DE2821136A1 - DOUBLE MEMBRANE BODY - Google Patents

Description

R. 45 1 * State of the art

The invention is based on a double membrane body according to the preamble of the main claim. Such a double membrane body is known (DE-OS 26 06 199).

In this known design, the membranes are flat disks with a sealing rim. A midrange does the switching work ^ and a between the central area and the clamping edge The lying ring area is exposed to stresses and deformations. The deformation resistance is proportionate high. As a result, a high pressure difference is required in order to switch such a double membrane body move. In addition, its service life is limited by the stresses that occur. Finally, its mid-range is as Closing body for a valve seat cannot always be used because it suffers deformations caused by stresses.

Advantages of the invention

The double membrane body with the characterizing features of the main claim has the advantages that it is more flexible and the switching work is not significantly influenced by intrinsic forces.

Furthermore, it is only small in its preformed ring area Exposed to deformations. This increases its service life. In addition, the individual switching membrane in their Use as a closing body, even with small pressure differences and low pressure levels, reliably sealing without

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too large effective diameter / f "" cTer with large pressure difference a Too high a load on the switching membrane would result. Furthermore

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each switching diaphragm in the area of a valve seat covered by it has only slight tension, so that it has the Valve seat slightly completely covered. Finally, two identical membranes can be used for the double membrane body are assembled with each other in opposite positions.

The use of the double diaphragm body in switching valves of brake anti-lock systems is particularly advantageous because there Low switching forces and fast switching at a low pressure level and a long service life despite the high pressure level are required are.

drawing

Several exemplary embodiments of the invention are shown in the drawing and explained in more detail in the description below. It shows: Figure, 1 "." The built-in double membrane body in its two end positions, FIG. 2 a neutral position of the double membrane body and FIG. 3 the initial shape of the not built-in, individual membranes of the double membrane body.

Description of the invention

A double membrane body 1 is with the interposition of an annular Spacer 2 clamped in a valve housing 3. That Spacer 2 has a contact surface 18 in the axial direction ei'wer membrane has a larger diameter and on a contact surface 19 a / jer membrane a smaller diameter. On the On one side of the double diaphragm body 1, a valve seat 4 is provided in the valve housing 3, which allows pressure medium to pass through is determined by a main valve, not shown, to an eccentrically arranged brake cylinder connection 4 ';

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the passage of pressure medium can be monitored by the double diaphragm body 1. On the other side of the double diaphragm body 1, a control chamber 5 is provided, which can be charged with control pressure medium is. The double membrane body 1 consists of two membranes 6 and 7, each of which has a thickening 8 and 9 in the middle, and between the diaphragms 6 and 7 is an annular intermediate piece 20 so that they are a certain distance from one another maintained. The intermediate piece 20 has a larger diameter in the axial direction on a contact surface 21 on the one membrane 7 and a smaller diameter on a contact surface 22 on the other membrane 6. It is built in the other way around as that Spacer 2.

As shown in FIG. 1 b , the double membrane body 1 rests in its one end position on a slightly raised floor 10 on one side of the control chamber 5. The valve seat 4 is open. When pressure medium is fed into the control chamber 5, the double diaphragm body 1 moves into its other end position, in which it closes the valve seat 4. This position of the double membrane body 1 is shown in Fig- * Xa .

It can be seen that at one transition 11 and 12 of the two Diaphragms 6 and 7 only show a slight deformation and thus little flexing work takes place.

FIG. 2 shows a neutral or inoperative position of the double diaphragm body 1. It can be seen that the arrangement is made so that the distance of the double diaphragm body 1 to the valve seat 4 is smaller than to the bottom 10 of the control room 5. This makes it easier to close the valve seat 4 guaranteed.

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Figure 3 shows the initial forms of the two not installed Membranes 6 and 7. It shows that both membranes are plate-shaped and identical and only in their Arrangement are mirror images of each other. Each membrane has a thickened outer edge 13, 13 ', on which it is interposed of the spacer 2 is clamped. Then follow inside a ring area 14, 14 'and a central area 15, 15', which the Thickening 8 or 9 carries.

Each ring area 14, 14 ″ is involved in the switching work of the double membrane body 1 exposed to flexing. In order to endure this better, the membrane parts 13, 13 '(outer edge) and 14, 14 '(ring area) or 14, 14' (ring area) and 15, 15 ' (Central area) arranged at an angle to one another and provided with a preformed transition 16, 16 '. This means that the plate-shaped membrane 6 or 7 in the delivery state with its transition 16, 16 'between the planar part and the conical part in the radial annular gap between the intermediate piece 20 and the spacer 2 lies.

If pressure is let into the control chamber 5, then the deformation is opposed the double membrane body 1 stood very small. There is substantial deformation of the preformed transition 16, 16 ' not necessary. A distortion of the double diaphragm body 1 in the area of the valve seat, which is common in known diaphragms 4 is significantly reduced here because the radius of curvature of the membrane 6 is retained. Through the great transition in the ring area 14 or 14 ', the same membrane can both valve seat and control room side can be used without one of the two diaphragms being overstretched. So it can do the the same membrane can be used with different effective diameters.

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The membrane 6, which is used as a closing body for the valve seat 4 is, is moved only in the area of their preform. This makes it very flexible and seals at a low pressure level even small pressure differences. Due to its low tension in the area of the valve seat, it is already tight with a small contact force. After all, it has a long service life and fatigue strength.

The use of the double membrane body described is particularly advantageous with switching valves of brake anti-lock systems, because there low switching forces and fast switching A long service life is required at a low pressure level and despite a high pressure level.

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Claims (6)

R. 46 N 1 April 17, 1978 He / Ht ROBERT BOSCH GMBH, 7000 Stuttgart 1 claims 1. Double diaphragm body as switching and closing body of a valve, which is clamped with its two outer edges in a valve housing with the interposition of a spacer, which also has a central area, optionally provided with a thickening, with which it is used to actuate the valve can move out of a starting position, and which has an annular area between the clamping edge and the central area, which is exposed to flexing stresses during the switching work of the double membrane body, characterized in that each membrane (6, 7) of the double membrane body (1) in the dismantled, tension-free state between two arranged at an angle to one another Membrane parts (13, 13 ', 14, 14') one in the sense of their pressure actuation preformed transition (16, 16 ') and that each of the two membranes (6, 7) is assembled with the other opposite position. 2. Double membrane body according to claim 1, characterized in that its two membranes (6, 7) are the same. 909846/0461 ORIGINAL INSPECTED 2821138 3. Double diaphragm body according to claim 1 or 2, characterized in that it is arranged between a valve seat (4) and a control chamber (5) and between the valve seat (4) and a bottom (10) of the control chamber (5) and that the Double diaphragm body (1) in its unactuated starting position
to the valve seat (4) has a smaller distance than to the bottom (10) of the control chamber (5) (Figure 2). 4. Double membrane body according to one of claims 1 to 3, characterized in that a
Intermediate piece is arranged, which has a larger diameter and its contact surface (22) on the other membrane (6) to achieve different membrane effective surfaces in the axial direction on its contact surface (21) on the one membrane (7)
has a smaller diameter. 5. Double membrane body according to claim 4, characterized in that the spacer (2) and the Zv / ischenstück (20) each have a contact surface (19 or 21) of larger diameter and a contact surface (18 or 22) of smaller diameter and that Spacer and spacer installed in opposite directions
are. 6. Double membrane body according to claim 4 or 5, characterized in that that the preformed membrane transitions (16, 16 ') in the 909846/0461 Annular gap between the spacer (2) and the intermediate piece (20) are arranged. 909846/0461