GB2271655A

GB2271655A - Computer-bus-controlled valve trigger

Info

Publication number: GB2271655A
Application number: GB9319139A
Authority: GB
Inventors: Peter Saffe; Georg Geier; Hans F Meyer; Huu-Tri Nguyen
Original assignee: Mannesmann AG
Current assignee: Vodafone GmbH
Priority date: 1992-09-22
Filing date: 1993-09-15
Publication date: 1994-04-20
Anticipated expiration: 2013-09-15
Also published as: IT1272597B; FR2696017A1; ITMI931933A0; ITMI931933A1; DE4232519C2; DE4232519A1; GB9319139D0; FR2696017B1; GB2271655B

Abstract

To obtain a computer-bus-controlled power valve trigger in a compact, application-specific design for use with valve batteries, the computer bus is connected via a corresponding bus line (11) with the input of an ASIC (21) (Application Specific Integrated Circuit) for decoding and control signal preparation. Further the power valve (1) is triggered by the control signal output of the ASIC (21) via a semi-conductor micromechanical pilot valve (22). <IMAGE>

Description

- I- COMPUTER BUS-CONTROLLED VALVE TRIGGER 2271655 The invention relates

to a computer bus-controlled valve trigger.

European Patent Application 0155751 describes a computer bus-controlled valve trigger in which a microcomputer is triggered via a data bus. This microcomputer processes the trigger signal and defines a control command which is supplied to a "valve-actuator" as designated therein, or pilot valve, via a DA convertor. The valve-actuator triggers the power valve at the output. No information is given about any particular construction of the pilot valve.

The use of a conventional microcomputer to evaluate the computer bus signal is extremely expensive, since the solution is one of software. Although such a software-type computer bus-controlled valve trigger can be individually adapted to a series of functions for each specific application by simple access to the software, it has been shown that in most cases valve triggers operate according to a specifically defined control pattern which is sufficient for the corresponding specific application. If the application of such computer bus-controlled valve triggers is in the field of valve batteries, central decoding would seem oversized and consequently too expensive.

It is amongst the objects of the invention to provide a computer buscontrolled valve trigger in a compact and application specific design, in particular, for use for valve batteries.

In accordance with the present invention, the trigger comprises a computer bus connected via an appropriate bus line to the input of an ASIC for decoding and control signal preparation, the power valve being triggerable by the control signal output of an ASIC via a micromechanical semiconductor. Preferably the ASIC and the micromechanical pilot valve f or each power valve to be triggered are combined to form a unit.

The above-mentioned ASIC is an Application Specific 2 Integrated Circuit component, the circuitry of which, compared with a microcomputer, is reduced to a minimum of integrated components necessary exclusively for the specific application thereof. The essential function of the ASIC used in the context of the invention is decoding and control signal preparation. Use of an ASIC for decoding and control signal preparation with a view to use f or an entire valve battery means that such an ASIC is provided for each individual power valve. ASICs are considerably cheaper as a rule than complex microcomputers and thus represent a solution to the price problem. However, the invention does not merely consist in the use of an ASIC, but rather also in such usage in conjunction with a semi-conductor micromechanical pilot valve, suitably connected downstream. The stipulation of both features ASIC and micromechanical pilot valve - is based on the knowledge that micromechanical pilot valves can, as a rule, be triggered with extremely small electrical control signals. Use of the micromechanical pilot valve thus enables power amplifier at the control signal output of the ASIC to be dispensed with and the micromechanical pilot valve to be triggered virtually directly via the ASIC. Such triggering represents a substantial simplification compared to computer bus-controlled valve triggers known hitherto. Since both ASICs and semi-conductor micromechanical valves can be produced in bulk with constant reproducible quality, altogpther a reliable, simple and economical solution results.

The unit formed by the combination of ASIC and pilot valve is so small that it may, if necessary, be easily integrated into a plug-in connection housing. Simple retrofitting is thus also possible. To this end, it is provided in one exemplary embodiment that the ASIC and the semi-conductor micromechanical pilot valve be integrated on a common semi-conductor substrate body. Such an interconnected pilot component may then also be manufactured in bulk in a manner tailor-made for any specific application.

3 In a further embodiment, both electrical and pressure medium-conveying lines are integrated in the semi-conductor substrate body. In conjunction with the proposed possible embodiment integrating this pilot component into a plug, it is possible for the pressure medium supply of the micromechanical pilot valve to be effected via the pressure mediumactuated connection with the pressure medium lines of the power valve to be triggered.

This means that a valve battery may be constructed in such a way that pressure medium supply is directly effected exclusively at the power valve battery and the pilot valve is supplied at the same time, such that only the bus line is linked up externally to the attachment plug, which bus line is optionally connected through from one plug to the next. The bus line may then simultaneously be the carrier for the supply voltage for the respective ASIC(s) and at the same time carry the coding signal for triggering the associated valve(s). Each attachment module associated with a valve, which module in turn includes the ASIC, defines or represents the corresponding decoding key for the individual valve. This means that, although the coding signal is present at each valve as a result of the loopingthrough of the bus line from one valve to the next, only the appropriately coded ASIC accepts the trigger command and then triggers its valve.

In a preferred form of the further embodiment, components for temperature compensation may be provided on the semi-conductor substrate body. It is further proposed to integrate a micromechanical semi-conductor pressure sensor on the semi-conductor substrate body.

Overall therefore, decentralised decoding of the coded bus signal is achieved. The arrangement thus represents a hardware solution with the aid of the ASIC, in contrast to the known microcomputer solution, which is a software solution and thus more expensive. The design of the proposed computer bus-controlled valve trigger ensures that 4 triggering of pressure-medium actuated valves is at last effected via a single coherent component. The combination of an ASIC and micromechanical valve is, moreover, as a series of tests has shown, a pneumatically low- loss combination, especially as the pilot part is substantially simplified with respect to known valves as a result of the micromechanical construction form thereof.

The invention will now be further described by way of example only with reference to the drawings, in which:- Figure 1 is a schematic diagram illustrating the individual interacting parts of a trigger of the invention; and Figure 2 shows a practical embodiment of the trigger.

Figure 1 shows in a schematic form the interaction of the individual components forming the trigger. From a control apparatus 10, which is in turn also connected with an SPS, there runs a bus line 11 to a pilot unit 20. The pilot unit 20 consists of an ASIC 21, a micromechanical pilot valve 22 and an integrated electrical and pressure medium-conveying line system 23. Both the power valve 1 and the line system 23 of the pilot unit 20 are connected via the pressure medium supply line P. Information is supplied from the control apparatus 10 to the ASIC 21 via the bus line 11.

In the valve battery, in which there are a plurality of power valves and accordingly a plurality of pilot units, each ASIC 21 is responsible, as a result of appropriate coding thereof, for accepting or not the control command of the control apparatus 10. In such a valve battery, the bus line 11 is conveyed to each ASIC 21 of each pilot unit 20. Thus, a control command emitted by the control apparatus 10 is present simultaneously at all the pilot groups or at all the ASICs 21 of the entire valve battery. The individual ASICs are coded in such a way that the only pilot unit 20 which accepts the control command is that which also comprises the code emitted by the control apparatus 10.

After acceptance of the control command by the ASIC 21, a control signal is electrically generated which is supplied to the pilot valve 22 without additional electrical power amplification outside the ASIC. The control signal amplifier internal to the ASIC is completely sufficient for triggering. The pilot valve 22 is constructed as a micromechanical semiconductor valve and accordingly is actuated by a correspondingly small trigger signal. A connection exists with the pressure medium supply connection P via the integrated line system 23, such that the pilot valve 22, triggered via the ASIC 21, switches the pressure medium present to a control surface 2 of the power valve 1. In this exemplary embodiment the power valve 1 is actuated against a reset spring 3, such that, when the control command is removed via the bus line 11 of the ASIC 21, the micromechanical pilot valve 22 is deactivated and the control pressure at the control surface 2 thus drops. When the control pressure at the control surface 2 has dropped, the desired switching state is achieved in a construct ion-dependent manner. In this illustrated example the pressure medium line P is switched into the working line A when the power valve I is in the rest state.

The upper part of Figure 2 shows an arrangement of power valves 1 with attachment plugs 30. The complete pilot unit 20 or at least the ASIC 21 and the micromechanical pilot valve 22 is integrated into the attachment plug 30. From the control apparatus 10, the bus line 11 is "looped through" from one plug 30 to the other through the entire valve battery 4 as illustrated in the lower part of Figure 2. The integrated pressure medium and electrical line system 23 of the pilot unit 20 may also be so constructed that the pressure medium supply line P is looped through from one valve 1 to the other to supply the micromechanical pilot valves 22 whilst, separately therefrom, the line 11 passes from one valve to the other.

6 The control apparatus 10 is usually supplied with 24 volt,direct voltage via an electrical supply connection 12. At the same time it is possible for the electrical supply of the individual ASICs 21 as well as, optionally, the components integrated on the semi-conductor substrate body of the ASICs 21 to be effected via the bus line 11. The coded control command can readily be modulated upon the "bus line" which then, in fact, serves as an electrical supply line.

In an alternative advantageous arrangement, the ASICs 21 and the pilot valve 22 are combined into one unit 20 which is also combined in a pilot module 11, such that the plug 30 has only a purely electrical connecting function.

In a further, very important, embodiment, the decoding function of the ASICs 21 is extended additionally to guidance or coding and decoding of sensor signals of externally triggered actuators. This means guiding signals from sensors via the given bus system, which sensors are arranged on the actuators, are triggered by the corresponding valve. This is made possible by the computer bus-controlled valve arrangement.

Overall the described arrangements allow a central decoding unit, which is associated centrally with a valve assembly, to be dispensed with. Such a central decoding unit is electronically very expensive and is only worthwhile for a large number of valves in a valve battery or valve unit. With a relatively small number of valves in a valve battery the capacity of such a central decoding unit is excessive. In the present arrangement, each valve is provided with its own "decoder key" with integrated pilot valve, moreover, such that the valve battery may be extended to an unlimited individual number of valves without provision having to be made for an, otherwise usual, central decoding unit. Even with a relatively small number of valves, for example two or three, the otherwise oversize arrangement of a central decoding unit with 7 superfluous, unused control outputs can be dispensed with. A further constructive or electrical simplification consists in the fact that the bus signals may also be applied or modulated on the supply voltage.

Claims

8 1. A computer bus-controlled trigger, for at least one power valve comprising a computer bus connected via a corresponding bus line with the input of an ACIS (Application fipecific Integrated Circuit) for decoding and control signal preparation, the power valve being triggerable by the control signal output of the ASIC via a micromechanical semiconductor pilot valve.
2. A trigger as claimed in Claim 1, wherein the ASIC and the micromechanical pilot valve for the or each power valve to be triggered are combined to form a unit.
3. A trigger as claimed in Claim 2, wherein the unit is integrated inside a plug element.
4. A trigger as claimed in either Claim 2 or 3, wherein the unit is combined in a pilot module.
5. A trigger as claimed in any one of Claims 2 to 4, wherein the ASIC and the respective micromechanical pilot valve are integrated on a common semi-conductor substrate body.
6. A trigger as claimed in Claim 5, wherein the semi-conductor substrate body is provided with both electrical and pressure medium connections and pressure medium lines are integrated in the semi-conductor substrate body.
7. A trigger as claimed in either Claim 5 or Claim 6, wherein the semi-conductor substrate body is provided with an integrated semi-conductor micromechanical pressure sensor.
8.

1 A trigger as claimed in any one of Claims 5 to Q 1 9 wherein compensation components or circuits are integrated on the semi- conductor substrate body.
9. A trigger as claimed in any preceding Claim for a series of power valves, wherein an ASIC and a micronechanical semi-conductor pilot valve are provided f or each power valve and the bus line is connected through f rom one valve to another.
10. A trigger as claimed in any preceding Claim, wherein the bus signals are modulated on thesupply voltage.
11. A trigger as claimed in any preceding Claim, wherein the ASIC(s) additionally guides and/or codes and/or decodes sensor signals externally triggered actuators.
12. A trigger substantially as hereinbef ore described and illustrated in the accompanying drawings.