DE3331013A1 - Displacement transducer for the slidable valve element especially of a hydraulic plunger valve - Google Patents

Abstract

The invention relates to a displacement transducer for determining the position of the valve element (2) in a plunger valve. For this purpose a slide (4) of brass or the like is fixed on the valve element (2), which slide carries a permanent magnet (5). When the valve is adjusted the latter moves in relation to two proximity sensors (8, 9), which are enclosed by a plastic support (6). Sphere of application: automation or safeguard to prevent incorrect operation, especially in hydraulic circuits. <IMAGE>

Description

CU v3 «3 I Kf I

Patent attorneys
Dipl.-Ing. W. Beyer
Dipl.-Wirtsch.-Ing. B. Jochem

Frankfurt / Main Staufenstrasse 36

Note: Bennes Marrel SA
Zone Industriel Sud
Andrezieux Boutheon - Loire
(France)

Description; Position transmitter for the displaceable valve member of an in particular hydraulic piston valve

Position transmitter for the displaceable valve member of a particular hydraulic piston valve

The invention relates to a position transmitter for the shift Valve member of a particularly hydraulic piston valve.

A wide variety of hydraulic piston valves with a displaceable valve member are known, the actuation of which takes place in different ways, namely by hand, automatically or remotely. The valve member is moved from one to another of different positions, which is able to take it and corresponding to each of a given switching state in the hydraulic circuit.

The object of the invention is to provide a simple and reliably working position transmitter for such a piston valve create, which at every moment the determination of the position of the valve member with delivery of information allowed, the characteristic of the respective valve member position is.

The advantage of such a position transmitter is not only that it enables a display to be made at any given moment makes the connection effected by the valve visible, but also in the delivery of information that is, for example can be processed in an electronic data center. It is known that the development of automation and allows the electronics to automatically trigger certain successive programs or to block them certain movements of a machine, if specified conditions etc. are met. The invention allows Delivery of information that can be used at any time in such automation computers.

-Z-

As a particular application example, but not limited thereto, the invention aims at a hydraulic distributor or Directional control valve as it is provided for controlling the movements of a lifting arm carried by a truck. It is known that in order to avoid any wrong actuation and to suppress any risk of reverse movement of the vehicle container there is a need to provide automatic devices, which certain movements of the lifting arm depending on the weight of the load to be handled, the inclination of the floor surface supporting the truck, the length of the telescopic boom of the lifting arm etc. allow or block.

A trained according to the invention position transmitter for the displaceable valve member of a piston valve, which this Satisfies requirements and meets the aforementioned advantages, is characterized by a sliding piece made of non-magnetic Material that moves in a fixed connection with the valve member together with this and at least one permanent magnet carries, while non-magnetic support means are arranged around the slider, which with at least one magnetic proximity sensors are provided, which generates an electrical signal every time the permanent magnet moves is in the vicinity of the proximity sensor, or none Signal generated when it is at a distance.

According to a first feature of the advantageous embodiment of the invention, each proximity sensor is a reed switch (Protective tube contact) formed.

When the invention relates to a position transmitter for a piston valve with three switching positions of the valve member, namely a middle position and two end positions is used, there is a further advantageous embodiment aarin "that the magnetic support means two magnetic approximation

-A-

- ε-

wear sensors in adjacent positions which the Permanent magnet occupies when the valve member is in the one or the other of the two end positions is located, while the permanent magnet is in the middle position of the valve member between the two proximity sensors.

Finally, there is one final design feature of the Invention is that the position sensor has a non-magnetic casing with a terminal box for fixed connection to a having electronic monitoring or display circuit.

The invention is explained in more detail below with reference to a preferred exemplary embodiment shown in the drawing. Show it

a longitudinal section through a hydraulic piston valve with one designed according to the invention Positioner and

Fig. » 2 shows a cross section along line II-II in FIG. 1.

In the drawing, a piston valve is shown, the fixed housing of which has various channels for connection to one another or on the contrary to the separation from one another according to the respective position of a displaceable piston-shaped Valve member 2 contains. The illustrated embodiment is a standard version with three switch positions, namely

= a middle position shown in FIG. 1;

- two end positions taken by shifting to the left or right, " each of which is a specific one

Supply of the hydraulic circuit corresponds.

According to the invention, a connecting piece 3 is attached to one end of the valve member 2, on which a sliding piece 4 from is attached to non-magnetic material. The slider 4 can for example consist of brass. A permanent magnet 5 is fitted into it.

The slider 4 follows the movements of the valve member 2 and thereby slides inside a fixed support 6, which in turn consists of non-magnetic material such as a plastic, super polyamide or other. The arrangement is in a non-magnetic Sheath 7 added, which consists for example of aluminum. In the plastic of the support 7 are two magnetic proximity sensors 8 and 9 fitted, for example formed by so-called reed switches (protective tube contacts) could be. Such switches are known to consist of magnetic contacts which are fused into a glass tube and by a magnetic field of an external coil, a Electromagnet or a permanent magnet are operated.

These reed switches are in an electronic circuit (not shown) switched on, which can be of any known design.

A socket provided with terminals for a permanent connection allows the reed switches 8 and 9 to be connected and their connection with the electronics circuit.

The function of the arrangement described above is as follows:

When the piston valve is in its neutral position, the valve member 2 takes the middle position shown in FIG. 1 on »In this case the permanent magnet 5 is at the same distance between the two reed switches 8 and 9, which do not provide any electrical signal.

If the valve member 2 is now shifted to the right to a corresponding circuit of the hydraulic circuit, the permanent magnet 5 comes close to the reed switch 9, which then sends a pulse to the electronic monitoring circuit.

Conversely, when the valve member 2 moves to the left in order to produce a different hydraulic switching state, the permanent magnet 5 approaches the reed switch 8 and this now supplies a signal to the electronic circuit.

As can be seen, the position transmitter according to the invention can Piston valves can be adapted with two or three positions. It enables the user to be informed that the valve member 2 was subject to movement »

In the embodiment shown, the transferred motion is interrupted _t when the valve member 2 in the neutral central position is returned (for example, under the action of a return spring 11).

Blank page

Claims (1)

Claims β J Position sensor for the displaceable valve member of a piston valve, characterized by a slider (4) made of non-magnetic material, which moves in a fixed connection with the valve member (2) together with it and carries at least one permanent magnet (5) while around the slider non-magnetic support means (6) are arranged which are provided with at least one magnetic proximity sensor (8, 9) which generates an electrical signal every time the permanent magnet (5) is in the vicinity of the proximity sensor (8 or 9), or does not provide a signal if it is at a distance. ο Position transmitter according to claim 1, characterized that each proximity sensor (8, 9) is designed as a reed switch (protective tube contact). 3 "detector according to claim 1 or 2 for a piston valve having three positions of the valve member, namely a middle position and two end positions, characterized f in that the non-magnetic support means (6) comprises two magnetic proximity sensor (8, 9) in each case adjacent to carry the positions which the Permanent magnet (5) occupies ₍ when the valve member is in one or the other of the two end positions, while the permanent magnet (5) is in the middle position of the valve member (2) between the two proximity sensors (8, 9). ο Position transmitter according to one of the preceding claims, characterized in that it is a non-magnetic Sheathing (7) with a terminal box (1o) for permanent connection to an electronic monitoring s- ~ or Display circle has »