EP1013941B1 - Assembly for controlling positioning members - Google Patents

Description

The invention relates to an assembly of a pilot valve and four Switching valves, in particular for controlling actuators, wherein the Pilot valve is a 4/3-way valve.

Such an assembly may form a 5/3 or 4/3-way valve and allows, for example, a double-acting hydraulic cylinder as an actuator head for. As pilot valves usually slide valves used, in particular two electromagnetic pilot valves, wherein the Valve center position is taken at non-energized pilot valves and for the first and the second eccentric switching position of the slider that one or the other pilot valve is controlled. A similarly high or even higher input tax expenditure exists with corresponding diaphragm valves in 5/3 and 4/3 ways. Especially when using These valves in valve islands lined-up design results in a high Effort for the preparation of the electrical connections of the solenoid contacts the pilot valves to an electrical control terminal block

From US-A-3,556,144 is an assembly according to the preamble of Claim 1 known. Here, a slide valve is used as a pilot valve.

The object of the invention is the control of fluidbetätigten To simplify 5 / 3- and 4/3-way valves such that all three switching positions the valves switched by a single solenoid of a pilot valve can be.

This object is characterized in an assembly of the type mentioned by solved that the pilot valve includes a housing in which two control chambers are formed, which are insulated from each other and each have a working connection and two pressure ports, with two of the ports each a sealing seat are provided, and a switching element which is pivotable in Housing is mounted and in each switching chamber has a sealing part, which with the sealing seats can interact such that these open or are closed, and an actuator for the switching element, wherein the Actuator can bring the switching element in three positions. To this Way reduce the effort and the volume of construction for the two so far provided electromagnetic pilot valves on the lower cost and the smaller volume for a single pilot valve. This facilitates the attachment of the valves to valve terminals and the interconnection of such Valves to a common electrical supply line and a fluid supply line.

Advantageous embodiments of the invention will become apparent from the Dependent claims.

• Figur 1 schematisch ein Stellglied mit verschiedenen Schaltungsvarianten;
• Figur 2 schematisch ein erstes Schaltschema für ein Stellglied;
• Figur 3 schematisch ein zweites Schaltschema für ein Stellglied;
• Figur 4 schematisch einen Teil eines Gehäuses eines Vorsteuerelementes mit Steuerkammer und darin angeordnetem Dichtteil;
• Figur 5 in einer schematischen Schnittansicht ein Vorsteuerelement;
• Figur 6 schematisch ein Betätigungsorgan, das bei den Vorsteuerelement von Figur 5 verwendet werden kann;
• Figur 7 in einer schematischen Draufsicht ein Schaltelement, das bei dem Vorsteuerelement von Figur 5 verwendet wird;
• Figur 8 einen schematischen Querschnitt durch die beiden Steuerkammern des Vorsteuerelements von Figur 5;
• Figur 9 schematisch das erste Schaltschema für ein Stellglied mit einem Vorsteuerelement gemäß einer ersten Ausführungsform;
• Figur 10 schematisch das erste Schaltschema für ein Stellglied mit einem Vorsteuerelement gemäß einer zweiten Ausführungsform;
• Figur 11 schematisch das zweite Schaltschema für ein Stellglied mit einem Vorsteuerelement gemäß einer ersten Ausführungsform;
• Figur 12 einen Schnitt durch eine Ventilinsel mit Vorsteuerelement; und
• Figur 13 in größerem Maßstab einen Ausschnitt aus der in Figur 12 gezeigten Ventilinsel.

The invention will be described below with reference to various embodiments, which are illustrated in the accompanying drawings. In these show:

• Figure 1 shows schematically an actuator with different circuit variants;
• Figure 2 schematically shows a first circuit diagram for an actuator;
• FIG. 3 schematically shows a second circuit diagram for an actuator;
• FIG. 4 shows schematically a part of a housing of a pilot control element with control chamber and sealing part arranged therein;
• Figure 5 is a schematic sectional view of a pilot element;
• Figure 6 shows schematically an actuator which can be used in the pilot element of Figure 5;
• Figure 7 is a schematic plan view of a switching element used in the pilot element of Figure 5;
• FIG. 8 shows a schematic cross section through the two control chambers of the pilot control element of FIG. 5;
• 9 shows schematically the first circuit diagram for an actuator with a pilot control element according to a first embodiment;
• FIG. 10 schematically shows the first circuit diagram for an actuator with a pilot control element according to a second embodiment;
• Figure 11 schematically shows the second circuit diagram for an actuator with a pilot element according to a first embodiment;
• Figure 12 is a section through a valve terminal with pilot element; and
• Figure 13 on a larger scale a section of the valve terminal shown in Figure 12.

With reference to Figure 1 is now generally the control of an actuator described, which is shown here as a double-acting actuator cylinder 1. The actuating cylinder 1 has a piston 2 and a working chamber 3 on the left side of the piston 2 and a working chamber 4 on the right side on the working chamber 3 is with a Terminal A provided, and the working chamber 4 is provided with a terminal B.

In the representations a) to c) of Figure 1 are different types of control shown the adjusting cylinder. In each example, a 4/3-way valve is used. In the each left switching position, the working chamber 3 with a pressure under a P. pressurized fluid, for example, compressed air, while the right working chamber. 4 is connected to a serving as a return port R. The piston 2 is thus after acted on the right. In the respective right switching position, the working chamber 4 via the Terminal B with the pressure P applied, while the left working chamber 3 with the Return line R is connected. Therefore, the piston 2 is urged to the left.

The three switching examples differ with regard to their center position. In the middle position shown in Figure a) a float circuit is realized at the two working chambers 3, 4 are connected to the return line R. The piston 2 is therefore free to move. The switching example in illustration b) realized in the middle position a blocking position in which the two working chambers 3, 4 each with the pressure P be charged. The piston 2 is thus blocked against movement. In the example of Representation c) is also a blocking position realized, in which case the two Working chambers 3, 4 are each closed off, so closed. Again, the piston is 2 blocked.

In Figure 2, an example of the control of an actuating cylinder is described, in which case solenoid valves M are used as pilot valves, which are connected to switching valves S ₁ and S ₂ . Depending on the assignment to the right or to the left working chamber of the actuator, the solenoid valves and switching valves are provided with the index L or R.

An excitation voltage U can be applied to the solenoid valves. The Switching valves are provided with a pressure port P and a return port R.

Depending on the control of the solenoid valves M can be achieved with the circuit shown in Figure 2 different types of control for the actuator 1. The various possibilities are given in Table 1 below. U _L U _R S _1L S _2L S _1R S _2R operating mode 1 0 0 P _too R _open P _too R _open Drive freely movable 2 L 0 P _open R _to P _too R _open Drive to the right 3 0 L P _too R _open P _open R _to Drive to the left 4 L L P _open R _to P _open R _to Drive fixed

The letter P stands in the table for a pressure connection, and the letter R stands for a pressureless return line.

The switching states 1 to 3 shown in the table correspond to the circuit FIG. 1a). The switching states 2 to 4 shown in the table correspond to the circuit FIG. 1b).

In Figure 3, another type of circuit of the actuator 1 is shown. The resulting operating modes are shown in Table 2 below. U _L U _R S _1L S _2L S _1R S _2R operating mode 1 0 0 P _too R _to P _too R _to Drive fixed 2 0 L P _too R _up P _on R _to Drive to the left 3 L 0 P _on R _to P _too R _up Drive to the right 4 L L P _on R _up P _on R _up Drive fixed

The switching states 1 to 3 shown in Table 2 correspond to the circuit according to Figure 1c). The switching state 4 shown in Table 2 corresponds to a short circuit from P to R.

Instead of pilot control by solenoid valves, the use of different Solenoid valves required, the same types of circuits by a single Precontrol can be achieved, which is designed as a 4/3-way valve.

With reference to the figures 4 to 8 is now generally the structure of such Pre-control element described. The pilot element 10 has a housing 12, in which two adjacent, mutually insulated control chambers 20, 30th formed, of which in Figure 4 only one can be seen. Each control chamber opens Working connection and two pressure connections, whereby the working connection with A or B is designated and the pressure ports are designated P and R respectively. Two of the connections in each control chamber 20 and 30 are provided with a sealing seat 21, 22 and 31, 32, respectively. With the sealing seats 21, 22 and 31, 32 operates generally by the reference numeral 14th provided switching element together. The switching element 14 can by acting on a Operating extension 15 from a rest position out into a first and a second position to be moved. Overall, therefore, three positions of the switching element 14 are possible. to Actuation of the switching element 14, an actuator 16 is provided (see in particular Figure 6), for example, as an electromagnetic drive with a polarized drive element is executed, the permanent magnet in the de-energized state a coil causes a middle position of the actuating extension 15 and at Current flow as a function of the current direction, the actuating arm either in Direction of the arrow 1 or in the direction of the arrow 2 adjusted.

In FIG. 6, the two positions 1 and 2 are one on the actuating extension 15 attached magnets 17 shown. The coil of the actuator is with the 18, and the switchable voltage source is shown in FIG Reference numeral 19 provided.

The basic structure of the switching element 14, which consists of a core 11 and a this surrounding elastomer 13, and the storage of the switching element in Housing 12 is basically known from German Utility Model 295 07 380, on the express reference is made. The details of the design of the switching element will therefore not be explained further here.

With reference to Figures 7 and 8, the operation of the pilot element will now described in more detail. The switching element 14 projects into each control chamber 20, 30 with a Seal member 24 and 34 into it. The two sealing parts 24, 34 are fixed to the Operating extension 15 are connected and simultaneously with the actuating extension emotional. The two sealing parts 24, 30 are arranged in different planes, ie mutually crossed. On the other hand, those on the upper side of the Control chambers 20, 30 arranged sealing seats 21, 31 as well as on the lower side of the Control chambers arranged sealing seats 22, 32 each at the same level.

If, starting from the rest position shown in FIG. 8, the sealing parts 24, 34 Be applied to the top, there is no in terms of the control chamber 20 Change in the switching state, since the sealing member 24 elastically deformed and continue to the sealing seat 21 is present, while the sealing member 34 in the control chamber 30 from the sealing seat 32 lifted and printed against the sealing seat 31. In contrast, if the sealing parts 24, 34 are applied downward, no results in terms of the control chamber 30 Change the switching state, while the sealing member 24 of the control chamber 20 from Sealing seat 21 lifted and pressed against the sealing seat 22. It is obvious that Deviating switching states can be achieved by the assignment of the connections suitable reversed. It is also possible, instead of mutually entangled Sealing parts to use those that are arranged in a plane, if at the same time mutually offset sealing parts 21 and 31 or 22 and 32 are used.

The circuit shown in FIG. 9 is based on the circuit shown in FIG used instead of the solenoid valves M shown there, the known from Figures 4 to 8 Pilot element. The circuit shown corresponds to the example shown in FIG. 1a). In the starting position shown in Figure 9, in which the two pressure ports P of Vorsteuerelementes are closed, a floating circuit is realized, in which the two Working chambers of the actuator are connected to R.

In Figure 10, a similar circuit is achieved, in which case the assignment of the Ports of the pilot element has been changed. The achieved circuit corresponds to the Example from FIG. 1b). In the initial position of the valve element, in which the two Return ports R are locked, the piston of the actuator is by bilateral Pressurization with P blocked.

FIG. 11 shows the pilot control element known from FIG. 9 with that from FIG. 3 known circuit of the switching valves combined. This results in the known from Figure 1c) Circuit, wherein in the rest position shown in Figure 11, in which the two Pressure ports P of the pilot element are blocked, both the two Working chambers of the actuator and the ports P, R are locked.

In the figures 12 and 13, finally, a valve block is shown by Combination of the switching valves S with a pilot element according to FIGS. 4 to 8 achieved. Well recognizable is the particularly compact design, which results because only one Pilot coil is required. In this way, a special suitability for the results Use in a valve series system with continuous pneumatic Supply strip and electrical connection strip for the power supply or Control of the coils with digital pulses from fieldbus technology. Furthermore results a high flow rate, since only a few flow diversions are required. Since all Components of the pilot control and the switching valves are made frictionless results a particular suitability for unlubricated use (without basic lubrication with dry compressed air) with little wear and a long service life.

Claims (5)

1. An assembly comprised of a pilot valve (10) and four switching valves (S), in particular for the driving of actuators (1), the pilot valve (10) being a 4/3-way valve, characterized in that the pilot valve includes a housing (12), in which two control chambers (20; 30) are formed which are isolated from one another and each include one working port as well as two pressure ports, two of the ports being provided with one respective sealing seat (21, 22; 31, 32), and a switching element (14) which is mounted for swivelling motion in the housing (12) and has a sealing part (24; 34) in each control chamber (20; 30), the sealing part (24; 34) being adapted to cooperate with the sealing seats (21, 22; 31, 32) such that they are opened or closed, and an actuating member (16) for the switching element (14), the actuating member (16) being adapted to move the switching element (14) into three positions.
2. The assembly as set forth in claim 1, characterized in that the sealing seats (21, 22; 31, 32) of a control chamber (20; 30) are arranged opposite each other on the one and the other side of the control chamber and the sealing part (24; 34) arranged in this control chamber is in contact with either the one or the other sealing seat.
3. The assembly as set forth in claim 2, characterized in that the sealing parts (24; 34) arranged in the two control chambers extend in different planes and in the resting position one of the sealing parts (24) is in contact with the sealing seat (21) arranged on the one side of the corresponding control chamber (20), while the other sealing part (34) is in contact with the sealing seat (32) arranged on the other side of the other control chamber (30).
4. The assembly as set forth in any of the preceding claims, characterized in that the switching valves (S) are diaphragm valves.
5. The assembly as set forth in any of the preceding claims, characterized in that the switching valves (S) have a flow boosting function.

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