DE102015205549A1 - METHOD FOR CALIBRATING A HYDRAULIC MACHINE - Google Patents

Abstract

The invention relates to a method for calibrating an adjustable hydraulic machine with an electronic control unit and an adjusting device having an adjusting element which is movable via an electrically controllable coil in a lying between a first end position and a second end position angle range proportional to a coil current. In this case, a first current value passing through the coil and an associated first deflection value are detected in the first end position, and a second current value passing through the coil with an associated second deflection value is detected in the second end position. From the first angle value and the first current value and from the second angle value and the second current value, the machine-specific deflection value-current characteristic of the adjustment element is determined by linear interpolation and provided to a control software of the control electronics. The invention further relates to a hydraulic machine which is designed for carrying out the method.

Description

The invention relates to a method for calibrating an electronic control unit of an adjustable hydraulic motor with an adjusting device having an adjusting element which is movable via an electrically controllable coil in a lying between a first end position and a second end position adjustment range proportional to a coil current, according to the preamble of the claim 1. The invention also relates to an adjustable hydraulic machine according to the preamble of claim 6, which is particularly suitable for carrying out the method.

The invention is based on an adjustable hydraulic machine in axial piston design, as for example DE 10 2005 060 960 A1 is known. This hydraulic machine has a cylinder block which is arranged on a valve segment pivotally mounted in a housing. The valve segment is connected via a pin with an actuating piston whose movement is electrically actuated via a proportional solenoid. For this purpose, the proportional magnet adjusts the position of a control cylinder, whereby hydraulic fluid flows, which act on the control piston, are changed. As a result, the position of the adjusting piston changes, which carries over the pin the valve segment and thus the cylinder block. By pivoting the valve segment with the cylinder block, the displacement of the hydraulic machine can be specified.

In DE 101 19 236 C1 is a largely similar hydraulic machine described in which the pivoting of the adjusting element designed as a yoke with the cylinder block is limited by adjusting screws on the housing. The adjusting screws form stops for the yoke and determine its end positions of the pivoting.

Hydraulic machines according to the prior art usually have an electronic control unit, which may be an integral assembly of the hydraulic machine. Often, however, the control electronics is a separate assembly of the hydraulic machine remote from the hydraulic machine and is mounted at a different location on the work machine, particularly as part of the main control of a work machine. However, the control electronics of the hydraulic machine is usually connected to the same via electrical lines. For the sake of simplicity, it is assumed in the context of the present invention description that the control electronics form a unit together with the hydraulic machine.

By means of the control electronics, the adjustment or deflection of the actuating piston and thus the intake or delivery volume of the hydraulic machine can be commanded or predetermined. However, the control electronics requires this knowledge of the control characteristic of the hydraulic machine, which indicates the relationship between the coil current at the proportional solenoid and the associated value of the adjustment or deflection of the adjustment. Here, the Verstellwert in hydraulic machines in axial piston design, for example, the displacement of a control piston, of which the pivot angle depends in a non-linear manner. Frequently, however, the swivel angle is used directly as Auslenkwert and the Verstellkennlinie the hydraulic machine indicated as a linear relationship between the swivel angle and coil current. In hydraulic machines in radial piston design of the adjustment value corresponds for example to a displacement, which z. B. is a measure of the set eccentricity of the machine shaft.

Due to tolerances in production, the characteristics of otherwise identical hydraulic machines of a series are different. Ie. Although these characteristics generally have a similar linear course, but the current value at a minimum or maximum angle of the deflection differs tolerances from hydraulic to hydraulic machine. This means that the slope and the respective position of the characteristic can be different in a Verstellwert-current diagram for different hydraulic machines of the same series. This is exemplary in 1 shown. In practice, this means that when specifying a general, average characteristic for all hydraulic machines of a series inaccuracies in the control of the hydraulic machine must be taken into account, or that a calibration of each hydraulic machine is carried out on a test bench. Both are undesirable. The latter is also complicated and costly, since such a calibration in the prior art usually takes place on the volume flow delivered or discharged by the hydraulic machine. A calibration via the only indirectly determinable volume flow is also associated with measurement errors that adversely affect the accuracy of the control of the hydraulic machine.

When calibrating a characteristic curve of an adjustable hydraulic machine, it should be noted that the deflection range of the adjusting element is limited between two end positions. Although the current position of the actuating piston via sensors can be detected, such as in DE 101 19 236 C1 is described, but it lacks a reliable and accurate indication of what conditions / at which parameter values the respective end position of the pivoting is reached. Only if a sensor with further commanded change in the deflection of the adjustment no further Changes in the position recorded, it can be assumed that an end position is reached and a further command for the adjustment is no longer required. Furthermore, this also means that no clear information is available for adjustment parameters in which the adjustment leaves an end position. Thus, in the case of the methods known in the prior art for commanding an adjustment, for example, for a deflection of the adjusting device from the minimum position with a force equal to zero, the force can be increased substantially linearly. However, only above a certain threshold, the force is large enough to effect an adjustment. The time that elapses until the power is ramped up is called dead time. In this time, there is no change in the deflection, ie no change in volume flow on the hydraulic machine. If, in the calibration methods known hitherto, the force could suddenly rise, ie, the force for swinging out abruptly set to a value which theoretically corresponds to the threshold value of the force, the jerking swinging out of the adjusting element can occur if the real threshold value is lower due to tolerance , Especially when starting or accelerating a traction drive, this is an undesirable effect. Accordingly, such a jerky adjustment continues over the entire deflection range, since all Ausschwenkpositionen are commanded oversteered.

The invention is therefore based on the object to provide a simple method for individual calibration of the characteristic of a hydraulic machine, and to provide a hydraulic machine which is suitable for carrying out the method. The costs for carrying out the calibration and the components required for this purpose should be as low as possible. Furthermore, the method should largely avoid dead times in the control of the deflection of the hydraulic machine, as well as a jerky deflection behavior, d. H. Starting, accelerating or decelerating a work machine.

The solution of this object with regard to the method is carried out according to the characterizing part of claim 1, characterized in that in a first end position, a coil passing through the first current value and an associated first angle value is detected, that in a second end position, a coil passing through the second current value and an associated second deflection value is detected and that from the first Auslenkwert and the first current value and from the second Auslenkwert and the second current value, the machine-individual Auslenkwert-current characteristic of the adjustment is determined by linear interpolation and that the Auslenkwert -Strom characteristic of a control Software of the control electronics is provided.

In a preferred embodiment of the invention, means for detecting the reaching or leaving an end position of the adjusting element are provided. It is further preferred to design these means as electrical sensors or switches which, upon reaching or leaving an end position, generate an electrical signal which can be transmitted to an electronic computer control of the hydraulic machine or to an external evaluation unit.

Preferred means for determining the two end positions of the pivoting of the adjusting elements are mechanical components of the hydraulic machine and can be carried out, for example, by adjusting screws or other fixed or adjustable stops in the path of movement serving for adjusting the displacement or delivery volume assemblies. These assemblies are, for example, an adjusting piston, a cylinder block bearing yoke, a swash plate, the shaft of a radial piston unit or the like.

When carrying out the method according to the invention, the coil current is ramped starting or decreasing, for example, starting from a minimum or maximum value, and the value of the current when reaching or leaving an end position of the adjusting element is determined and detected. For this purpose, z. B. via the control software of the hydraulic machine, or via an external input device, the coil current through the proportional solenoid of the adjusting increases from a value "zero" rising ramped. Upon reaching a first threshold value of the applied current, the actuating piston starts to move. It is assumed that the adjustment initially in a rest position at a contact area, for. B. is located on a housing which corresponds to a first end position and which may be defined by a stop. The stop can also, for example, the adjustment, z. B. the adjusting piston, the valve segment or the yoke of the cylinder block. When leaving the end position, ie when the adjusting element is released from the stop, a sensor or switch responds and transmits a corresponding signal to the control electronics, which then determines and stores the current value currently applied to the proportional magnet. Upon further increase of the current fed to the coil of the adjusting piston or the yoke reaches the second end position, which is determined for example by a further stop. An additional sensor associated with this end position is responsive to this and transmits a signal to the control electronics upon reaching it. This determines and stores the associated second current value. The rise of the coil current is stopped. Preferably, however, the threshold for the current required to reach an end position is slightly exceeded. or below, depending on whether it is the maximum or minimum position of the deflection. This provides a certainty that the respective end stop has been reached safely.

From the stored first and second current values and the associated deflection values of the first and second end positions, the control electronics calculates the characteristic curve defined in each case by these current values, wherein preferably a linear profile is used as the basis. This individually calibrated characteristic is transmitted to the control software of the hydraulic machine and stored there. Such a customized and individual for each hydraulic machine individually determined characteristic curve for the dependence of the angular position of the coil flow of the adjustment is thus available for the exact control of the intake or delivery volume of the hydraulic machine. This is a clear advantage over the prior art, in which no individual determination and exact specification of the control characteristic is provided, but only an empirically determined, which is often available only as one of a limited number of hydraulic machines averaged desired characteristic.

With regard to the device, the solution according to the invention of the object consists in that the hydraulic machine has means for detecting and detecting the reaching or leaving of an end position of the adjusting element. These means are preferably mechanical, electrical or magnetic sensors or switches, of which in each case one sensor is assigned to an end position of the adjusting element. Alternatively, it is also possible to use only one sensor or switch, which detects the entire deflection range of the adjusting element, including the two end positions. Such a sensor may for example be an angle sensor on the yoke of the cylinder block or on the swash plate of an adjustable axial piston machine. In a further preferred embodiment, such a sensor detects at least a partial region of the deflection region and remaining deflection regions of the displacement element until reaching switches arranged in the end position (s) are linearly interpolated. Swivel angle sensors, which sense the entire deflection range, can thus be further avoided.

Preferably, the hydraulic machine has electrical components as part of a sensor device for detecting the end positions, of which each one of the first end position and another of the second end position is assigned and which form part of an electronic measuring circuit in the respective end position of the adjusting element. In the embodiment of the invention, these electrical components may be arranged concretely on or in components of the hydraulic machine which, upon pivoting of the adjusting element between the two end positions, come into electrically conductive contact with the adjusting element, eg. B. the yoke on the cylinder block or involved in its adjustment components. Examples include known adjusting screws, which serve as stops for the adjusting element, for example. The cylinder block or its yoke. Also conceivable is an arrangement on the adjusting device for the cylinder block, such as in a movable between two end positions servo piston, wherein the servo piston in its respective end position makes contact of the components with an electrically conductive part of the hydraulic machine. It is understood that the arrangement according to the invention can also be used to determine only a single end position.

In the embodiment of the invention, it is preferred that the hydraulic machine has an adjusting device for the adjusting element that can be actuated by a solenoid and that the magnetic coil is part of the measuring circuit. It is advantageous if the hydraulic machine has control electronics, via which the current through the magnetic coil can be predetermined and monitored. In this case, such control electronics is usually arranged away from the hydraulic machine on a work machine and connected via, for example, electrical lines to the hydraulic machine. For the explanation of the invention, however, it is assumed that the control electronics with the hydraulic machine structurally forms a unit.

In a particularly preferred embodiment of the invention, the hydraulic machine has at least one adjusting screw for fixing the first or the second end position of the adjusting element, wherein a first terminal of an electrical component is arranged insulated from a contact surface of the adjusting screw, which contact surface with electrically conductive components of the hydraulic machine at Reaching the respective end position can come into contact. Upon reaching the end position of the adjusting element of the first terminal of the electrical component is grounded, so that an electric current can flow through the component. This additional flowing current is provided by the current or voltage source of the measuring circuit, which is operatively connected to a second terminal of the electrical component. The occurrence of the additional current, which starts when reaching the end position, is detected by the evaluation unit of the measuring circuit and provided as a signal. The evaluation unit of the measuring circuit can be integrated, for example, in the electronic control of the hydraulic machine.

Particularly preferred is in the embodiment of the invention that the second terminal of the electrical component is electrically connected to the magnetic coil. This connection has thus the same power or voltage supply, as the solenoid and uses the already existing in the hydraulic machine control and monitoring of the current through the solenoid coil by using this as part of the measuring circuit. To complete the measuring circuit then only an electrical component is required. It should be noted here that the partial current flowing via the electrical component should be significantly lower than the current through the magnetic coil. Otherwise, the coil current would be weakened too much and the force on the adjustment of the hydraulic machine would be affected. The resistance or the impedance of the electrical component, which may be a resistor, a capacitor or an induction coil, must therefore be high compared to the corresponding value of the magnetic coil.

It is particularly preferred that the electrical component is a resistor which is electrically connected in parallel to the magnet coil in the respective end position of the adjusting element.

The invention will be explained in more detail purely by way of example with reference to embodiments of an axial piston motor in oblique-axis design, which are illustrated in the figures. However, the explanations on the method according to the invention and on the adjustment device according to the invention with an electronic control unit can be interrogated by any hydraulic machine known from the prior art. This applies analogously to hydraulic pumps or motors, which are electronically controlled in their displacement or delivery volume, and equally for hydraulic machines in axial or radial piston design. Therefore, all known in the art hydraulic machines are included in the spirit of the invention. Show it:

1 a deflection value / coil current diagram for hydraulic machines;

2 a deflection value / coil current characteristic determined according to the invention;

3 a detail of a sectional view of a hydraulic motor according to the prior art;

4 a detail view of an embodiment of a hydraulic machine according to the invention;

5 a detailed view of another embodiment.

In 1 For example, a deflection value / coil current diagram for hydraulic machines is shown. The dependency of the swivel angle α of an adjusting device of an axial piston machine as a function of the coil current applied to the magnetic coil is shown by way of example 1 is marked. But also the displacement X of the servo piston depending on the height of the coil current could be used here for the determination of an individual characteristic curve. It should be noted in axial piston machines that the relationship between the displacement path X of the servo piston and the pivoting angle α of the adjusting element is present as an only approximately linear relationship. In radial piston machines could be used according to the displacement X as a measure of the eccentricity of the motor shaft.

The all or X / I characteristic is here, for example, when using a proportional solenoid for adjusting a hydraulic machine substantially linear, or results from the conversion of the linear displacement of the proportional solenoid to a corresponding displacement of the adjustment of the geometric conditions in the adjustment. Due to unavoidable tolerances in the production of the individual hydraulic machines, even if they are otherwise identical, the individual characteristics lie in a range which is limited, for example, by the characteristics A and B. For example, with a minimum value α _{1 of} a swivel angle α, which is assigned to a first end position, the associated current value I _1min according to the characteristic A is lower than the corresponding current value I _{1 max} according to the characteristic B. In the constructively predetermined maximum value α ₂ of Pivoting angle α, which corresponds to the second end position, there are analogous, but usually much larger differences in the current _values I _2min and I _2max according to the characteristics A and B. In the usual practice until now this fact is taken into account that, for example, statistical or arithmetic Mean values I ₁ and I _{2 are} formed, which are provided as a characteristic curve C of the control software of the hydraulic machine. This leads to a not exactly defined control behavior of the respective hydraulic machine. In particular, it is not exactly determined which maximum / minimum coil current I ₁ / I _{2 is} to be applied so that the maximum / minimum tilt angle α ₁ / α _{2 is} reached. In particular, hydraulic motors can generally only be disengaged from a mechanical drive train if their displacement is reliably set to zero in order to prevent over-rotation of the hydraulic machine in the no-load state. Is how out 1 shown for the prior art, no clear control current value I ₁ assigned to a zero-displacement volume, so further measures must be taken in general, which detect a zero-displacement and / or ensure so that a mechanical disengagement of a hydraulic motor can be done without damage.

In particular, in a coupling operation of a hydraulic motor in a mechanical drive train, it is helpful to know the associated current value to a desired deflection / tilt angle. A stationary hydraulic motor to be coupled can thus be commanded by jumpers to an intended deflection, in which case the optimum point in time for the engagement process can be determined more precisely. By means of the calibration method according to the invention, the volume flow thus set by the hydraulic machine can thus be unambiguously determined by a more precise knowledge of the current value associated with a deflection value of the hydraulic machine, whereby the reaching of the engagement speed can be calculated more precisely. This not only the engagement process is shortened in time - as a ramp-like start of the hydraulic motor is avoided - but also achieves a smoother engagement, since relative speeds between the clutch discs, such as a multi-plate clutch, are significantly reduced. This also increases the life of a clutch and makes the hydrostatic drive more robust.

2 shows a deflection value / coil current characteristic curve D determined specifically for a hydraulic machine according to the invention. Since both the current value I ₁ for the minimum pivot angle and I ₂ for the maximum pivot angle, ie for the respective end position of the pivoting, are individually determined and determined, the characteristic curve D is specific and exactly adapted to the associated hydraulic machine. This hydraulic machine is thus calibrated individually and thereby exactly with respect to the deflection, for example, the pivot angle controllable. Tolerance-related inaccuracies are largely eliminated.

It can be seen that with the inventive method of individualized calibration of a hydraulic machine not only dead times can be avoided, in which a starting point for Begin a deflection of the hydraulic machine can be commanded directly and suddenly. From there, the ramp-like rise for the actual deflection start. This also prevents a "bucking", which occurs when the commanded current value does not correspond to the Auslenkwert that is to be controlled. As a result of the calibration, it is also possible to avoid a jerky startup or readjustment, since the exact current value required for controlling the deflection is known. This also reduces the component load of the components involved in the adjustment of a hydraulic machine.

In 3 is an example of an adjustable hydraulic machine 1 in a detailed view of a axial piston in Schrägachsenbauweise according to the prior art shown in section. In a machine housing 2 of which only a small section is shown here is a cylinder block 3 in a yoke 4 arranged. The pistons not shown here in the cylinder block 3 are operated in a known manner by a rotating engine or drive a drive shaft, depending on whether a pump or a motor operation of the hydraulic machine 1 is provided. These details are familiar to the expert, so that it is possible to dispense with further explanations.

The yoke 4 is together with the cylinder block 3 in the case 2 pivotally mounted, wherein the respective end positions of the pivoting by adjusting screws 5 or other fixed or adjustable components of the hydraulic machine can be specified. In 3 is just one example of these adjustment screws 5 shown. It is here associated with the minimum angle of pivoting. Upon reaching this minimum angle comes a first end 15 of the yoke 4 with an end face of the adjusting screw 5 in contact, which is thus a stop 6 forms. It is understood that even the maximum angle of the pivoting of the yoke 4 such an adjustment screw 5 may be assigned, against which the second end portion 16 of the yoke 4 strikes. The yoke 4 has the role of the adjustment in this embodiment 4 , In swash plate hydraulic machines, this would be the swash plate and hydraulic machines in radial piston design, the eccentricity adjusting shaft.

The pivoting of the yoke 4 with the cylinder block 3 via an adjusting device 7 whose housing 8th with the machine housing 2 the hydraulic machine 1 is firmly connected. In the case 8th the adjustment 7 is an adjusting piston 9 arranged longitudinally displaceable. The displacement of the adjusting piston 9 is from a magnetic coil 10 controlled, which acts on a spool, not shown. The spool, not shown here controls in a known manner fluid flows, which on the adjusting piston 9 act and determine its position. A feather 11 serves as feedback to the spool. The adjusting piston 9 acts over a pin 12 who serves as a taker on the yoke 4 the hydraulic machine 1 one. An axial displacement of the adjusting piston 9 thus leads to a corresponding deflection 1 Pivoting of the yoke 4 and thus the cylinder block 3 , In this way, the displacement or delivery volume of the cylinder in the cylinder block 3 set. The control, usually designed as a proportional solenoid coil 10 , ie their supply of current or voltage, is performed by a control electronics, not shown here for the hydraulic machine 1 ,

The housing 8th the adjustment 7 is according to 3 by way of example with an end cap 13 provided as a stop 14 for the maximum deflection of the adjusting piston 9 can serve. This stop 14 defines the maximum pivoting position of the yoke 4 , It can therefore function as one of an adjusting screw 5 formed stop 6 take.

4 shows a hydraulic machine according to the invention in a section according to 3 , All reference numerals are retained in the following figures to designate identical structural features. The general structure and operation of the hydraulic machine 1 correspond to the basis of 3 described details.

In 4 is a measuring circle 20 shown, which is a source of current or voltage 22 having. The voltage source 22 is part of a not shown control of the hydraulic machine 1 and serves as an example for feeding the solenoid coil 10 with which they have lines 23a . 23b is actively connected. The magnetic coil 10 thus forms part of the measuring circuit 20 , One of the pipes 23a or 23b lies on earth 26 that of the general mass of the hydraulic machine 1 is formed. It can be assumed that the hydraulic machine 1 consists of metal and thus is electrically conductive.

The other part of the measuring circuit 20 is according to the invention of another line 23c and resistors 27a and 27b formed parallel to the magnetic coil 10 on earth 26 are legible. The resistance 27a is the adjusting screw 5 assigned and the resistance 27b the yoke 4 , The resistance 27a and the associated line 23c are in the adjusting screw 5 arranged electrically isolated, with a part 29 the line 23c at the as stop 6 serving end face of the adjusting screw 5 empties. this part 29 the line 23c forms a contact area at the end face 17 , which is electrically isolated from the other end face. The adjusting screw 5 associated first end region 15 of the yoke 4 also carries a contact surface with the contact area 17 the adjusting screw 5 can come into electrically conductive contact. This case occurs when the yoke 4 is in the position of least pivoting, ie when the end area 15 of the yoke 4 in contact with the stop 6 the adjusting screw 5 located. In this position thus becomes a partial current from the current or voltage source 22 over the wires 23c and 29 and the resistors 27a and 27b on earth 26 placed. The resistance 27b This may already be due to the limited conductivity of the material of the hydraulic machine 1 be given, so that may have its own discrete resistance 27b can be omitted.

Is the electrical contact between the contact areas of the yoke 4 and the adjusting screw 5 closed, a first partial flow of the measuring circuit flows 20 as before, by the solenoid 10 and another partial flow through the from the lines 23c and 29 and the resistors 27a and 27b formed branch of the measuring circle 20 to the mass 26 , This manifests itself in a sudden change in the parameters of the measuring circuit 20 as soon as the contact is closed. This parameter change, which consists for example of a change in the voltage or the current in the measuring circuit, can be detected by the electronic control of the hydraulic machine. Their appearance is thus a sure indication that the yoke 4 has reached an end position of his pivoting.

When dimensioning the resistors 27a respectively. 27b Care must be taken that the partial current flowing through them should be significantly lower than that through the magnetic coil 10 flowing electricity. Otherwise, contact would be closed between the contact areas 30 the adjusting screw 5 and the yoke 4 an unacceptably high reduction of the current through the solenoid coil 10 take place, resulting in a sudden and undesirable change in the pivoting angle of the yoke 4 could lead.

In the embodiment of the invention, it is also possible, the resistors 27a and 27b by replacing capacitors and / or inductors. The contact between the adjusting screw 5 and the yoke 4 occurring impedance change in the measuring circuit 20 can then be detected for example via a frequency or amplitude change in a resonant circuit.

In 5 a further embodiment of the invention is shown, in which case similar components with the same reference numerals as in the 3 and 4 are designated. As before, a branch of the measuring circle 20 from the solenoid 10 and the wires 23a and 23b formed with the current or voltage source 22 are connected. The other branch of the measuring circle 20 leads over the line 23c about the resistances 28a and 28b to the mass 26 , The resistance 28a is here at / in the end cap 13 the adjustment 7 arranged, with its output terminal electrically isolated to a contact area 18 in the end cap 13 arranged stop 14 is guided. The contact area 18 lies in the in 3 shown end position of the adjusting piston 9 a contact area 19 of the adjusting piston 9 opposite, both contact areas 18 . 19 are electrically connected. From the contact area 19 in the adjusting piston 9 leads an insulated line over the resistor 28b to the mass 26 , In this embodiment, the adjusting piston 9 the role of the adjustment element 4 , Since the adjusting piston 9 over the cone 12 play free with the yoke 4 coupled, corresponds to the end position of the adjusting piston 9 Functional of the end position of the yoke 4 and thus the cylinder block 3 ,

The stop 14 is in 5 shown as a solid stop in the end cap 13 is arranged or formed by them. Of course, this stop 14 be designed adjustable in embodiment of the invention. This permits, if necessary, a fine adjustment of the assigned end position of the adjusting device 4 and thus the cylinder block 3 ,

The operation of this embodiment of the invention is as follows: At a position of the adjusting piston 9 there is no electrically conductive contact between the contact areas between the end positions of its movement 18 and 19 in the end cap 13 and the adjusting piston 9 , Consequently, no current flows in the line 23c and the resistors 28a and 28b , However, the adjusting piston reaches the in 5 shown end position, so touch the contact areas 18 and 19 at the stop 14 and on the adjusting piston 9 , making a current across the resistors 28a and 28b to the mass 26 flows. The resulting sudden change in the conditions in the measuring circuit 20 serves to detect the reaching of the end position of the adjusting piston 9 and thus the yoke coupled with it 4 the hydraulic machine 1 ,

In a modification of the invention may also be a change in the conditions in the measuring circuit 20 consist in that when the removal of the adjusting element 4 from an end position of the current through the one or more electrical components suspends, since the contact with ground 26 is interrupted. The result of this sudden jump in the current in the measuring circuit 20 is then an indication that the assigned end position has been left. Even such a signal can from the control electronics of the hydraulic machine 1 be used. This case can occur, for example, when the coil current of the value "zero" is ramped. Since the adjusting piston usually comes only from a certain minimum value of the coil current in motion, this value must be reached until the adjusting piston 9 or the adjusting element 4 detach from the stop and thereby the partial flow of the measuring circuit 20 in this branch. This method is thus suitable both for reaching and leaving an end position of the adjusting elements 4 . 9 display.

As the adjusting piston 9 usually made of metal and over the housing 8th or other components electrically conductive with the general mass of the hydraulic machine 1 is connected, it is possible in the embodiment of the invention to the resistance 28b to renounce and the contact area 18 at the stop 14 directly with the end face of the adjusting piston facing it 9 to bring into contact. In this case, the modification of the adjustment limited 7 only on the end cap 13 that with the resistance 28a , the contact area 18 at the ready 14 and the line 23c to be provided. The respective electrically conductive contact areas 17 . 18 and 19 are preferably formed so that they are raised relative to the surrounding surface. This ensures a secure electrical contact when opposite contact areas come into contact with each other.

In the embodiment of the invention, it is readily possible, both embodiments described above in a hydraulic machine 1 to unite. Here, for example, the one end position of the pivoting of the yoke 4 in which the end region 15 of the yoke 4 in contact with the end face of the adjusting screw 5 lies, through a measuring circle 20 according to 4 be recorded. The other end position of the pivoting, which in 5 is shown and the maximum pivoting of the yoke 4 corresponds, can then by means of a measuring circuit 20 according to 5 be determined.

The invention thus provides a simple and reliable method for calibrating an adjustable hydraulic machine in axial piston design and the construction of a hydraulic machine specified, which is designed to carry out the method in a special way, wherein a retrofit invention already existing hydraulic machines performed by a professional without much effort can be and is also included in the inventive concept. At the same time an adjustable hydraulic machine is provided which has means for detecting the achievement of at least one end position of the pivoting of a cylinder block. Since the additional components used to implement the method according to the invention are simple in construction and, moreover, inexpensive, the calibration method according to the invention can be implemented overall at low cost.

LIST OF REFERENCE NUMBERS

1

hydraulic machine

2

casing

3

cylinder block

4

Yoke / adjustment

5

adjustment

6

attack

7

adjustment

8th

casing

9

adjusting piston

10

Kitchen sink

11

feather

12

spigot

13

endcap

14

attack

15

first end area

16

second end area

17

Contact area adjusting screw

18

Contact area End cap

19

Contact area adjusting piston

20

measuring circuit

22

Current or voltage source

23a, 23b, 23c

management

26

Dimensions

27a, 27b

resistance

28a, 28b

resistance

29

Part of the line

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102005060960 A1 [0002]
• DE 10119236 C1 [0003, 0007]

Claims (15)

Method for calibrating an electronic control unit of an adjustable hydraulic machine ( 1 ) with an adjusting device ( 7 ), which is an adjusting element ( 4 . 9 ), which via an electrically controllable coil ( 10 ) is movable in a lying between a first end position and a second end position deflection proportional to a coil current, characterized in that - in the first end position, a coil ( 10 ) passing first current value and an associated first Auslenkwert is detected, - that in the second end position, a coil ( 10 ) and a corresponding second deflection value is detected and - that from the first deflection value and the first current value as well as from the second deflection value and the second current value, the machine individual deflection value-current characteristic of the adjustment element ( 4 . 9 ) is determined by linear interpolation and - that the Auslenkwert-current characteristic of a control software of the control electronics is provided. A method according to claim 1, characterized in that means for detecting the reaching or leaving an end position of the adjusting element are present. A method according to claim 1 or 2, characterized in that the coil current is changed starting from a minimum or maximum value ramping starting or decreasing. A method according to claim 3, characterized in that the value of the current when reaching or leaving an end position of the adjustment is determined and stored. A method according to claim 4, characterized in that the first and / or the second end position of the adjusting element can be predetermined by mechanical means. Hydraulic machine with a coil electrically controllable by an electronic control unit ( 10 ), which in such a way on a movable adjusting element ( 4 . 9 ) can act, that the adjusting element between a first end position and a second end position is adjustable, characterized in that the hydraulic machine detecting means for detecting the reaching or leaving an end position of the adjusting element ( 4 . 9 ) and means with which the reaching or leaving the end position of the adjusting element ( 4 . 9 ) can be transmitted to the control electronics. Hydraulic machine according to claim 6, characterized in that the detection means are mechanical, electrical or magnetic sensors or switches, each of which a sensor or switch an end position of the adjusting element ( 4 . 9 ) assigned. Hydraulic machine according to claim 6, characterized in that the detection means comprise a mechanical, electrical or magnetic sensor which detects the deflection region including the first and the second end position at least partially. Hydraulic machine according to one of claims 6 to 8, characterized in that the hydraulic machine ( 1 ) Electronic Components ( 27a . 27b ; 28a . 28b ), of which one of the first end position and another of the second end position is assigned, and in the respective end position of the adjusting element ( 4 . 9 ) Part of an electrical measuring circuit ( 20 ) form. Hydraulic machine according to claim 9, characterized in that the coil ( 10 ) Part of the measuring circuit ( 20 ). Hydraulic machine according to one of claims 6 to 10, characterized in that the hydraulic machine ( 1 ) has an electronic control unit, via which the current through the coil ( 10 ) can be specified and monitored. Hydraulic machine according to one of claims 6 to 11, characterized in that the hydraulic machine ( 1 ) each have an adjustable stop ( 5 ) for determining the first and the second end position of the adjusting element ( 4 . 9 ) and that a first terminal of an electrical component ( 27a . 27b ; 28a . 28b ) isolated in a mechanical contact area ( 17 ) of the stop ( 5 ), which contact area ( 17 ) with electrically conductive components of the hydraulic machine ( 1 ) can come into contact when reaching the respective end position. Hydraulic machine according to claim 12, characterized in that a second connection of the electrical component ( 27a , b; 28a , b) with the coil ( 10 ) is electrically connected. Hydraulic machine according to one of claims 9 to 13, characterized in that the electrical component ( 27a . 27b ; 28a . 28b ) is a resistor or a capacitor or an induction coil. Hydraulic machine according to one of claims 9 to 14, characterized in that the electrical component is a resistor ( 27a . 27b ; 28a . 28b ), which in the respective end position of the adjusting element ( 4 . 9 ) electrically parallel to the coil ( 10 ) is switched.

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