SE531289C2 - Methods, apparatus and systems for operating a valve - Google Patents

Description

25 30 151 DJ .ä h) III: ut At least some of the above syllables and other advantages are achieved by a method, apparatus and system as set forth in the appended independent claims.

Additional advantageous properties appear from the non-independent claims.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be described in more detail in the following with reference to the accompanying drawings, in which: Fig. 1 is a schematic block diagram illustrating a control device connected to a valve, which device operates in accordance with the invention, Fig. 2 (a), (b) and (c) are the schematic block diagrams illustrating three positions of a valve having a transient, third valve element position, which valve is particularly suitable for use in a preferred embodiment of the invention, Fig. 3 is a schematic the timing diagram (tirning) diagram and illustrates characteristics of the valve shown in fi g. Fig. 4 is a schematic timing diagram illustrating further characteristics of the valve shown in Fig. 2; Fig. 5 is a schematic block diagram illustrating a preferred embodiment of a control device according to the invention, and Fig. 6 is a schematic flow diagram illustrating a method according to the invention.

DETAILED DESCRIPTION OF THE INVENTION None Fig. 1 is a schematic block diagram illustrating a control device connected to a valve and operating in accordance with the invention. 53% 239 The valve 1 10 is generally arranged to open or close a fluid flow from the flow output 122 to the flow output 124 as a function of a time varying control signal 104 supplied to the valve 110.

More specifically, the resulting flow through the valve is determined by an orifice area a of the fate limiter represented by the valve. The orifice area a is variable and is determined by the position of a valve element which is included in the valve. The valve element is movable between three positions, each representing a certain orifice area: a first, stable position corresponding to a closed valve position (orifice area a = A1 which is normally equal to zero) a second, transition position (transient position), corresponding to a semi-open valve position ( orifice area a = A 2), and a third, stable position corresponding to an open valve position (orifice area a = A 3). In general, A1 The position of the valve element is affected by a control element, more particularly a solenoid, which causes the valve element to move between the first and third positions of the valve as a function of the control signal 104.

The control signal typically consists of a pulsed, digital (on / off fi signal. During normal operation, the valve element will thus switch between its first, closed position and its third, open position, while the second, semi-open position becomes an unstable, transitional position. or transverse position of the valve.

The control device 100 is arranged to receive an input signal 102 corresponding to a desired valve action. More specifically, the input signal 102 represents a value representative of the resulting fate fate characteristic of the valve, such as a desired mean fate value. Normally, the value of the flow through the valve is highly dependent on pressure drying conditions and fluid characteristics. Therefore, in the case of a drawn embodiment, the input signal 102 represents a desired average orifice area ad of the fate limiter represented by the valve.

Figs. 2 (a), (b) and (c) are schematic block diagrams illustrating, by way of example, a valve 1 which may be used in connection with the invention, shown in three different positions. 10 15 20 25 30 53¶ The EâZ-S Valve 110 is a bistable on / off solenoid valve arranged to open or close the fl uidum fl flow from a fluid urn input 122 to a fl uidum output 124. The design features of the valve 110 are the same in each condition shown ( a) - (c).

The valve 110 comprises a movable valve element 112, more particularly a substantially cylindrical piston 112, made at least in part of a ferro-magnetic material.

The valve member 112 is slidably movable in a hollow, cylindrical sleeve which is open at a lower end and closed by a connected iron core 118 at the adjacent upper end.

More specifically, the valve member 112 is movable between a first, stable position, a second, transient position and a third, stable position, depending on the actuation of the actuating element 114, which typically consists of an electromagnetic coil formed as the cylindrical sleeve and concentrically arranged relative to the valve member 1 12.

The first, normal position of the valve element 112, shown in FIG. 2 (a), corresponds to a closed valve position, where the input 122 output 122 and thus the output 124 output 124 is zero. In this position, the control element 14 is not switched on. A spring 120 is arranged between the valve element 112 and the iron jaw 118, which causes the valve element 112 to be pressed against the valve seat 16 so that the valve is kept closed.

When the control element 114 is switched on by means of the control signal 104, the valve element 112 is retracted towards the iron core 118 to its third, open position, as shown in fi g. 2 (c). The valve element 112 is thus adapted to move between the first, closing position in fi g. 2 (a) and the third, open position in fig. 2 (c) as a function of the control signal 104.

Fig. 2 (b) shows the second, transient position of the valve 110, corresponding to a semi-open valve position. The lower end of the valve member 112 is provided with a guide chamber 111 at its lower end. The guide chamber 111 comprises an upper inlet mouth and a vertically movable disc 113 with a lower mouth. The provision of the control chamber 11 connected to the lower end of the valve element 112 means that the valve 110 will assume its second transient position, in which the flow through the valve is partly limited by the control chamber 11 and the mouth of the disc 113.

The control element 114 is switched on by the control signal 104. When the control element 114 consists of an electromagnetic coil, the control signal 104 can be represented by the voltage signal which is applied to the coil.

Those skilled in the art will appreciate that there are a number of different valve types than the valve shown in the example. 2 can be used in connection with the present invention. Suitable valves have a valve element which is movable between a first, stable position, corresponding to a closed valve position, a second, transient position corresponding to a semi-open valve position, and a third, stable position, corresponding to an open valve position. They also have an operating element for causing the valve element to move between said first and third positions as a function of a pulsed operating signal.

F ig. 3 is a schematic timing (timing) diagram showing certain timing and area characteristics of valves that may be utilized with the invention, such as the valve 110 shown in fi g. 2 (a) - (c).

The diagrams include two curves with a common time base along the horizontal axis.

The upper curve in Fig. 3 shows an illustrative example of an operating signal 104 supplied to the valve 110. The lower curve in fi g. 3 illustrates the flow area at the mouth of the valve 110 when the control signal 104 is applied.

Area A1 corresponds to the estuary area at the first, closed position, shown in fi g. 2 (a).

Normally A1 is equal to zero.

IA g orifice corresponding to the second, intermediate position, shown in fi g. 2 (b), the gap 122, 124 through the valve 110 is partially throttled by the guide chamber 111 with the disc 113.

A 3 is the mouth area corresponding to the third, fully open position, shown in fi g. 2 (c). 53% E85 The preferred control signal 104 makes a unit step from passive to active position at time T 0. Thereafter, the control signal 104 is kept constant until time T; when the activation signal returns to its passive state.

The resulting flow through the estuary area starts at A 1, which is normally 0. After T 0, the area changes and reaches its second value A 2 at time T 1. in the interval between T 0 and T; the area is not clearly defined.

Thus, T; valve 110 half-open time. It should be understood that T; as well as other characteristics shown in fi g. 3 can be easily determined by measurements and / or very simple experiments. Such characteristics can alternatively be communicated by a manufacturer as pre-given rating data for the valve.

The valve orifice is kept at A 2 as long as the vertically movable disc 113 abuts against the valve seat 116. When the valve element 112 begins to lift the movable disc 113, at time T 2, the effective orifice area changes again. In the interval between T 2 and T3, the area is not clearly defined.

At time T 3 the valve is completely open and the mouth area is equal to A 2.

At T4, the control signal returns to the passive state. The spring 120 will then retract the valve element 112 so that the resulting orifice area will return to its closed value A; (normally zero) at time T 5.

For simplicity, it is assumed that the closing time of the valve is equal to T 5-T 4 regardless of its position (ie its second, transient position or its third, stable position) at time T 4, when the control signal 104 is deactivated.

Fig. 4 is a schematic timing diagram showing further characteristics of the valve shown in Fig. 2. In contrast to the diagrams in fi g. 3, the control signal is switched back to its passive position before the valve has reached its third, fully open position. 10 15 20 25 30 531 E39 The diagram in fi g. 4 contains two curves with a common time base along the horizontal axis.

The upper curve in fi g. 4 illustrates an illustrative example of an operating signal 104 fed to the valve 110. The lower curve in fi g. 4 illustrates the resulting flow area in the mouth of the valve 110 when the control signal 104 is applied.

Area A1 corresponds to the first, closed position, shown in fi g. 2 (a). Normally A 1 is equal to zero.

A2 is the myrmíng corresponding to the second, intermediate position, shown in fi g. 2 (b), the gap 122, 124 through the valve 110 being partially throttled by the guide chamber 111 with the disc 113.

The preferred control signal 104 makes a unit step from passive to active state at time To. Thereafter, the control signal 104 is kept constant in the active state until the time T6, when the activation signal returns to its passive state. i The resulting flow area begins at A 1 which is typically zero. After T 0, the area changes and reaches its second value A2 at time T 1. In the interval between T 0 and T 1, the area is not clearly defined. Thus, T1-TÛ constitutes the half-open time of the valve 1 10.

This is similar to the example shown in fi g. 3.

The valve mouth is maintained at A2 as long as the vertically movable disc 1 13 abuts against the valve seat 1 16.

In this case, the control signal 104 returns to its passive state at T 6, which is earlier than the point T 2 (also compare fi g. 3) when the valve element 112 would begin to raise the movable disk 113 if the control signal had still been active. The spring 120 will retract the valve member 112, while the resulting orifice area returns to its closed value A 1 (typically zero) at time T 7. '10 15 20 25 30 531 E89 For simplicity, it is assumed that the valve closing time Ty-Tó is equal to as T 5-T 4 (as in fi g. 3) regardless of the position of the valve at the time (T 6) when the control signal 104 was deactivated.

Fig. 5 is a schematic block diagram illustrating the constructive design of the hardware for a wired embodiment of a control device in accordance with the invention.

The control device 100 is suitably implemented as one. functional part of a known device in the automotive industry as an electronic control unit, hereinafter referred to as Electronic Control Unit (ECU).

An Electronic Control Unit (ECU) is a centralized digital control unit, arranged in a vehicle, which unit can be used to regulate various functions in the vehicle. For example. For example, the ECU can regulate engine functions such as fuel injection or brake restrictions, such as the control of locking brakes. Alternatively or in addition, the ECU can regulate the transmission functions of the vehicle. In the case of automatic transmissions, for example, the ECU may set parameters associated with automatic transmission procedures.

In the present invention, a special ECU can be provided and configured in accordance with the invention to control a valve in the vehicle. The valve can e.g. consists of a control valve for a coupling.

The control device 100 comprises an internal line (bus) 510, which is operatively connected to a computer unit 550, in particular a microcomputer. A memory 520 is operatively connected to the line 510. The memory 520 includes a RAM portion 530 for storing temporary data during processing and a persistent memory portion 540, e.g. a Flash memory component for storing program instructions and fixed data.

The input signal 102 is supplied to the I / O adapter 560, which is operatively connected to the line 510. This enables the computer unit 550 to read the input signal 102. 53% EBS The output signal 104 provided by the I / O adapter 560 is operatively connected to the control element input of the valve 110. In this example, it is assumed that the I / O adapter 560 also contains the necessary drive circuits to drive the solenoid coil of the valve 1. Alternatively, such driving circuits are transmitted externally to the control device 00.

Although the signals 102, 104 are shown as separate signal lines to simplify the illustration, those skilled in the art will recognize that particular digital "bus technology" of the type commonly used in the automotive industry, such as CAN bus, may be suitably used for communication between the ECU and external components. the valve. In accordance with the present invention, the memory 520, and in particular the persistent memory portion 540, contains instructions for the computer which cause the computer unit 550 to perform the method of the present invention as described in detail below with particular reference to fi g. 6.

Suitably a split ECU is used. In this case, the hardware convolution in fi g. 5 represent the whole ECU. An operating system included in the memory 520 is provided for low level control of the hardware and to enable higher level computer program modules or parts held in the memory 520 to implement various control functions related to the operation of the vehicle. The present invention can in this case be put into operation by the described, shared hardware construction and a computer program part which performs the method according to the invention, operating in cooperation with the operating system.

Alternatively, the control device 100 may be implemented as a separate unit, Lex. as a separate unit similar to the ECU shown in fi g. 5.

Fig. 6 is a schematic flow diagram illustrating a method according to the invention.

The purpose of the method is to operate a three-position fl uidum valve, such as a valve described with reference to fi gur 2 (a) ~ (c) and fi g. 3 above, in accordance with the reference input signal ad. More specifically, the valve should be operated to exploit the potential of such a valve, especially the second, transient position of the valve element.

The method has the desired effective (resulting) valve orifice area ad as input.

The output of the method consists of the control signal 104, which is a digital pulse signal, which is suitably characterized by a pulse frequency f [Hz] and a relative pulse length level of dc [%] - For simplicity, it is assumed that the effective valve orifice area is A; and during the time interval T Û-T 1, i.e. at the transition from the first to the second position of the valve. In fact, the area is not clearly defined in this time interval, as indicated by a dashed, sloping line in Figures 3 and 4.

Furthermore, also for the sake of simplicity, it is assumed that the effective valve orifice area is equal to A 2 during the time interval T g-T 3. In fact, the area is not clearly defined in this time interval, as indicated by the dashed, sloping line in fi g. 3.

Furthermore, also for the sake of simplicity, it is assumed that the effective valve orifice area is equal to A 3 during the time interval T 4 ~ T 5. In fact, the area is not clearly defined in this time interval, as indicated by the broken, sloping line in Fig. 3. .

Furthermore, also for the sake of simplicity, it is assumed that the effective valve orifice area is equal to A 3 during the time interval T á-T 7. In fact, the area is not clearly defined in this time interval, as indicated by the dashed, sloping line in fi g. 4.

Furthermore, it is assumed that the pressure drop across the valve is constant and therefore does not affect the time delay of the valve.

The following constants are defined in the method: ATmode 1_ 2 is the time required to move the valve from the first, open position to the second, semi-open position, ie. AT Mg, 1.2 = T; - TO 10 15 20 25 30 535 2853 ll Aßäng, is the time required for the valve to return to the closed position, ie. AT s, ä ,, g, = T 5-1 '4 (or correspondingly, AT S ,, -, - ,, g, = T 7-T6) AT spike 1-3 = Tg - T 0 [ms ] is the time interval from the closed position of the valve (T 0) to its fully open position (T 3).

T glue, is the period length of the PWM pulse signal 104, when the valve is operated in the semi-open position, i.e. by means of the small valve curve A 2. Suitably this value is used for the signal period: Yjüen = AT position 1-3 = T 3- T 0. fi fzen = 1 / T but [Hz] is the PWM frequency of the pulse signal 104, when the valve is operated in semi-open position, ie. using the small valve opening A 2.

T m, [ms] is the period length of the pulse signal 104 in cases where the valve is operated in the fully open position, i.e. by means of the large valve mouth A 3. Suitably the value of T m is selected, which is mainly twice the value of T but, i.e. T 5.0, = 2 T ma, 12.0, = 1 / T ,,. ,, [Hz] is the PWM frequency of the pulse signal 104 in cases where the valve is operated in the fully open position, ie. by means of the large valve mouth A 3.

A 2 [mmz] is the small orifice area of the valve, ie. a predetermined valve parameter.

A 3 [mmz] is the large orifice area of the valve, ie. a predetermined valve pair.

Those skilled in the art will appreciate that all the parameters, characteristics or constants discussed above can be readily determined by measurements and / or very simple experiments based on the present description and the particular valve to be used in the invention. Some of these characteristics may alternatively be provided by the manufacturer as pre-given rating data. With a suitable valve for use in the invention, the value of A 3 is 4-8 times the value of A 2. The most suitable value of A 3 can be determined as a compromise between real time delay and precision requirements. As an example, A 3 can be set as 6'A2.

The method begins with the starting step 600.

In step 610, the reference input signal ad is obtained as the desired average valve orifice area [mm2].

The reference input signal ad can either be input as an existing physical signal or created as an output variable in another process performed by the control device.

In the comparison step 620, the process determines if the reference input signal ad is less than a predetermined first limit value amg. This limit value is previously determined based on the characteristics of the valve, including area and timing characteristics. More specifically, the limit value is suitably determined as alåg = A gAT fl âng / Th-æn.

If this test is positive, the process is repeated in step 610. Alternatively, the process continues in ironing step 630. Preferably, the relative pulse length of the pulsed control signal 104 is set to substantially zero, or the signal 104 is set to zero in another suitable manner, if the test is positive.

In jäniforse step 630, the process is correct if the iriput signal ad is larger than a second, predetermined limit value ahøgr. The second limit value is suitably determined in advance based on the characteristics of the valve, including area and timing characteristics.

More specifically, the second limit value is suitably determined as ahög, = (Af (A fl âge 1-3- ATzage 14) / ATlagez-s) If this test is negative, the process continues with the small orifice control step 640.

If the test is positive, the process continues with the large orifice control step 650.

In step 640, the control signal 104 is formed to provide small orifice control.

The control signal 104 is then formed as a pulse signal with relative pulse length calculated as a function of the reference input ad. Suitably, the pulse length is calculated as a first linear function of the reference input ad. The function suitably has constant parameters, based on calce, including area and timing characteristics. In particular, it is suitable that the relative pulse length is determined mainly as follows: dc z [position I-TATs force / T small + Ûd / AZ] In this case, in step 640, it is assumed that the frequency of the control signal is set to = f1, -, which is an advantageous feature of the invention.

The control signal is determined and generated directly by the control device 100 or that the frequency value and the value of the relative pulse length are transmitted to a PWM controller.

The control of the small orifice enables adjustment of the resulting fl uidum fl fate, in particular within a lower fault range of the total valve des range.

The resulting control signal is transmitted to the valve. Then, the process is repeated in step 610.

In step 650, the control signal 104 is formed to obtain control of the large orifice.

The control signal 104 is then created as a pulse signal with a relative pulse length calculated as a function of the reference input. Suitably, the relative pulse length is calculated as a second, linear function of the reference input ad. The function suitably has constant parameters that are based on valve characteristics, including area and timing characteristics. In particular, it is convenient if the relative pulse length is calculated mainly as follows: tsna- Antara i la; ha á uan fl uuann- a fi anawnnwøwn fi das -__- ëïi ”t” “- '? ~ ATW§:. + i., _ i rn i ~ a: 5-10094: 10 15 20 25 30 531 289 14 The relative pulse length of course also limited to a maximum of 100%.

In this case, in step 650, it is assumed that the frequency of the control signal is set to f = j}, o ,, which is an advantageous feature of the invention.

As will be appreciated from the above discussion, fm, (the frequency used to control the large orifice) is normally less than the flm (the frequency used to control the small orifice). Normally fw, = men / Z.

The control signal is determined and generated directly by the control device 100 or that the frequency value and the value of the relative pulse length are transmitted to a PWM controller.

The regulation of the large orifice enables coarse control of the resulting fl uidum fl fate, especially within an upper region of the total valve fl fate region.

The control signal is transmitted to the valve. In this case, the process is repeated in step 610.

Although not explicitly shown in fi g. 6, the process can of course be terminated by means of suitable operating conditions or operating means.

Although the invention has been described in particular with reference to a three-stage vacuum valve, the person skilled in the art realizes that the principles of the invention can also be applied to valves where a valve element has more than one transient position between its outer positions (closed and fully opened).

In accordance with the exemplary embodiment which we have explained in detail, the frequency of the control signal changes between two distinct values in two operating modes of the valve (small-mouthed - large-mouthed). However, those skilled in the art will recognize that there are alternative embodiments of the invention, where the frequency may be varied more than with respect to the two proposed values. The present invention is particularly applicable to clutch actuation valves. However, those skilled in the art will recognize that the invention can be used for a wide variety of hydraulic and pneumatic applications.

Claims (21)

10 15 20 25 30 531 E39 PATENT REQUIREMENTS 1. l. Method of operating a flow valve, characterized in that the valve comprises - a valve element movable between o a first, stable position corresponding to a closed valve position, o a second, transient position corresponding to a semi-open valve position and o a third, stable position corresponding to an open valve position, and - an operating element for causing the valve element to move between said first and third positions as a function of a pulsed actuating signal (actuating signal), the method comprising the step of varying the relative pulse length (duty cycle) of said pulsed control signal in accordance with a reference input for the purpose of utilizing the second, transient position of the valve element in the operation of the fluid valve. A method according to claim 1, wherein said reference input is a desired effective orifice area (ad) of the valve, and wherein the pulsed control signal is substantially set to zero if the desired effective orifice area (ad) is less than a first limit value (ajfåg,). A method according to claim 1 or 2, wherein the relative pulse length (dc) of the pulsed control signal is calculated as a first function of the reference input, if the desired effective field area (ad) is less than a second limit value (ahäg) The method of claim 3, wherein said first function of the reference input is a linear function of the reference input, the function having constant parameters, which are determined in advance, based on the characteristics of the valve, including area and timing characteristics. A method according to any one of claims 3 or 4, wherein the relative pulse length (dc) of the pulsed control signal is calculated as a second function of 10 53 53 l 289 f? the reference input, if the desired effective orifice area (ad) is greater than said second limit value (ahög) The method of claim 5, wherein said second function of the reference input is a linear function of the reference input, the function having constant parameters determined in advance on the basis of the valve characteristics, including area and timing characteristics. A method according to any one of claims 1-6, further comprising varying the frequency of said pulsed control signal in accordance with the reference input for operating the valve. The method of claim 7, wherein a first vens sequence (fl üen) is used for the pulsed control signal if the desired effective orifice area (ad) is less than said second limit value (ahögbt A method according to any one of claims 7 or 8, wherein a second frequency (fi u-jg) is used for the pulsed control signal, if the desired effective orifice area (ad) is greater than said second limit value (ahögg. A method according to any one of the preceding claims, wherein said limit values (amg, ahögg. Are dry hand determined, based on the characteristics of the valve, including area and timing characteristics. 11. l 1. Control device for operating a vacuum valve, characterized in that the valve comprises - a valve element which is movable between o a first, stable position corresponding to a closed valve position, o a second, transient position corresponding to a semi-open valve position and o a third, stable position corresponding to an open valve position, and - an operating element for causing the valve element to move between said first and third positions as a function of a pulsed operating signal (actuating signal), the operating element comprising a generator for said pulsed operating signal, configured to vary the relative pulse length of said pulsed control signal in accordance with a reference input for the purpose of using the second, transient position of the valve element in the operation of the vacuum valve. The control device of claim 11, wherein said reference input is a desired effective orifice area (ad) of the valve, and wherein the control device is configured to set the pulsed control signal to substantially zero if the desired effective orifice area (ad) is less than a first limit value (amg). A control device according to claim 11 or 12, wherein the control device is configured to calculate the relative pulse length (dc) of the pulsed control signal as a first function of the reference input, if the desired effective orifice area (ad) is less than a second limit value (ah) . The control device of claim 13, wherein said first function of the reference input is a linear function of the reference input, the function having constant parameters which are predetermined based on the characteristics of the valve, including area and timing characteristics. A control device according to any one of claims 11-14, wherein the control device is configured to calculate the relative pulse length (dc) of the pulsed control signal as a second function of the reference input, if the desired effective orifice area (ad) is greater than a second limit value ( ahög,> _ A control device according to claim 15, wherein said second function of the reference input is a linear function of the reference input, which function has constant parameters which are predetermined and based on valve characteristics, including area and timing characteristics. 10 15 20 25 53 "? 285 lci A control device according to any one of claims 11-16, wherein the control device is additionally configured to vary the frequency of said pulsed control signal in accordance with the reference input for operating the valve. A control device according to claim 17, wherein a first frequency (fi yoke) is used for the pulsed control signal, if the desired effective orifice area (ad) is less than said second limit value (a high). A control device according to any one of claims 17 or 18, wherein a second frequency (fi mg) is used for the pulsed control signal, if the desired effective orifice area (ad) is greater than said second limit value (ahögu A control device according to any one of claims 1 1-19, wherein said limit values (ahögf, amg) are predetermined and based on characteristics of the valve, including area and timing characteristics. 21. A system for operating a vacuum valve, characterized in that the system comprises - a vacuum valve, which comprises a valve element movable between a first, stable position corresponding to a closed valve position, a second, transient position corresponding to a semi-open valve position and a third, stable position corresponding to an open valve position, and - an operating element for causing the valve element to move between said first and third positions as a function of a pulsed actuating signal (actuating signal), and - a control device as claimed in any one of claims 11- 20 for operating the valve.