Patents by Inventor Christian Hoffmann
Christian Hoffmann has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
-
Patent number: 6459244Abstract: A method and a device for charging a capacitive actuator are described. The capacitive actuator, in particular for a fuel injection valve of an internal combustion engine, is charged or discharged with different charging and discharging times. In order to shorten the charging time, the capacitance of the recharging capacitor which is dimensioned for a maximum charging time is reduced at a predefined time during the charging process. Two exemplary embodiments of a device for carrying out the method are explained in more detail.Type: GrantFiled: January 7, 2002Date of Patent: October 1, 2002Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Wolfgang Lingl, Richard Pirkl
-
Patent number: 6441535Abstract: A control element, in particular a piezoelectrically operated fuel injection valve in an internal combustion engine, is charged, in order to compensate for stochastic reactions in the internal combustion engine, with a constant nominal voltage applied to a series circuit that includes a charge capacitor and a charge reversal capacitor, and it is discharged into the charge reversal capacitor to a prescribed voltage value. The remaining residual charge of the control element is charged into the charge capacitor via a limiter path.Type: GrantFiled: January 16, 2001Date of Patent: August 27, 2002Assignee: Siemens AktiengesellschaftInventors: Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Christian Hoffmann, Richard Pirkl, Günther Riedel
-
Publication number: 20020093313Abstract: A method and a device for charging a capacitive actuator are described. The capacitive actuator, in particular for a fuel injection valve of an internal combustion engine, is charged or discharged with different charging and discharging times. In order to shorten the charging time, the capacitance of the recharging capacitor which is dimensioned for a maximum charging time is reduced at a predefined time during the charging process. Two exemplary embodiments of a device for carrying out the method are explained in more detail.Type: ApplicationFiled: January 7, 2002Publication date: July 18, 2002Inventors: Christian Hoffmann, Wolfgang Lingl, Richard Pirkl
-
Publication number: 20020088741Abstract: In a high gradient magnetic separator with a separation zone consisting of a matrix of parallel magnetic wires arranged in parallel planes and channels formed by a non-magnetic material and extending in each plane between adjacent parallel magnetic wires for conducting a fluid including magnetic particles through the matrix, and a magnetizing structure disposed adjacent the matrix for generating a magnetic field with field lines which extend essentially normal to the parallel planes, separating walls are disposed in parts of the channels in the area ahead of the end of the magnetic field generated in the matrix and adjacent the flow exit end of the matrix so as to extend parallel to the planes and normal to the magnetic field lines and form partial flow channels receiving partial fluid flows of magnetic particle-enriched and, respectively, magnetic particle-depleted flow volumes.Type: ApplicationFiled: January 18, 2002Publication date: July 11, 2002Inventors: Matthias Franzreb, Wolfgang Holl, Christian Hoffmann
-
Publication number: 20020074266Abstract: In a high gradient magnetic separator with a separation zone consisting of a matrix of parallel magnetic wires arranged in parallel planes and channels formed by a non-magnetic material and extending in each plane between adjacent parallel magnetic wires for conducting a fluid including magnetic particles through the matrix, and a magnetizing structure disposed adjacent the matrix for generating a magnetic field with field lines which extend essentially normal to the parallel planes, separating walls are disposed in parts of the channels in the area ahead of the end of the magnetic field generated in the matrix and adjacent the flow exit end of the matrix so as to extend parallel to the planes and normal to the magnetic field lines and form partial flow channels receiving partial fluid flows of magnetic particle-enriched and, respectively, magnetic particle-depleted flow volumes.Type: ApplicationFiled: February 19, 2002Publication date: June 20, 2002Inventors: Matthias Franzreb, Wolfgang Holl, Christian Hoffmann
-
Patent number: 6366868Abstract: A method of diagnosing an actuator includes supplying a predeterminable amount of energy to an actuator through a charge-reversal circuit. Faulty functional statuses of the actuator and its supply lines and/or its drive circuits, short- or long-term interruptions, short-circuits within the actuator or its supply lines, or excessively low capacitance values may be deduced from a discrepancy between reference values and determined variables including actuator voltage, actuator current, and actuator charge. A short-circuit of an electrical connection within the actuator or an electrical connection between the drive circuit and the actuator can be deduced if the actuator voltage is less than a lower voltage value. An interruption in the electrical connection within is the actuator or an electrical connection between the drive circuit and the actuator may be deduced if an actuator peak current is less than a lower current value. An apparatus for performing the method is also provided.Type: GrantFiled: March 30, 2001Date of Patent: April 2, 2002Assignee: Siemens Aktiengesellschaft AGInventors: Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Christian Hoffmann, Richard Pirkl, Walter Schrod
-
Patent number: 6361306Abstract: A tool arrangement for the manufacture of ring-shaped compacts using a rotary compression press wherein the rotary compression press has a rotatably driven die-plate having die holes in which die inserts are mounted, and upper and lower rams aligned towards the die inserts and rotating together therewith, which are moved by control portions towards each other or away from each other and wherein the bottom rams have a coaxial bore open to the operating end in which a central pin is disposed which is axially located relative to the die-plate by a transverse pin wherein the transverse pin extends through an axial slot of the lower ram, wherein the transverse pin is located in a ring which forms part of a guide bore for the lower ram which is formed in a radially outwardly facing projection of the die-plate, two bracket-shaped retaining clips are disposed on opposed sides of the lower ram a longer leg of which abuts against the underside of the ring and a short, second leg of which is bent over the projection, aType: GrantFiled: June 6, 2000Date of Patent: March 26, 2002Assignee: Wilhelm Fette GmbHInventors: Jürgen Hinzpeter, Ulrich Zeuschner, Christian Medicus, Christian Hoffmann, Jürgen Schikowski, Andreas Arning, Hans-Wilhelm Christiansen
-
Patent number: 6333585Abstract: A capacitive actuator (P), especially for a piezoelectrically operated injection valve for an internal combustion engine, is short-circuited by a discharge switch (M) after an actuation, the controlling input of the discharge switch (M) being connected to the actuator (P) so that the discharge switch (M) in case of a failure of the external control, is automatically rendered conductive by the actuator voltage (UP) and the actuator (P) is therefore automatically discharged.Type: GrantFiled: August 15, 2000Date of Patent: December 25, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Richard Pirkl
-
Publication number: 20010039484Abstract: A method of diagnosing an actuator includes supplying a predeterminable amount of energy to an actuator through a charge-reversal circuit. Faulty functional statuses of the actuator and its supply lines and/or its drive circuits, short- or long-term interruptions, short-circuits within the actuator or its supply lines, or excessively low capacitance values may be deduced from a discrepancy between reference values and determined variables including actuator voltage, actuator current, and actuator charge. A short-circuit of an electrical connection within the actuator or an electrical connection between the drive circuit and the actuator can be deduced if the actuator voltage is less than a lower voltage value. An interruption in the electrical connection within the actuator or an electrical connection between the drive circuit and the actuator may be deduced if an actuator peak current is less than a lower current value. An apparatus for performing the method is also provided.Type: ApplicationFiled: March 30, 2001Publication date: November 8, 2001Inventors: Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Christian Hoffmann, Richard Pirkl, Walter Schrod
-
Patent number: 6297941Abstract: A device for controlling an electromechanical actuator with an actuating element and an actuating drive. The actuating drive includes an electromagnet which has a core and a coil. The actuating drive, furthermore, has a moveable armature plate. A controller is provided, the control variable of which is the current through the coil and the actuating variable of which is a voltage applied to the coil. A voltage source generates a supply voltage and a pulse width modulator modulates the actuating variable as a function of the supply voltage.Type: GrantFiled: December 6, 1999Date of Patent: October 2, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Richard Wimmer, Achim Koch
-
Publication number: 20010020804Abstract: A control element, in particular a piezoelectrically operated fuel injection valve in an internal combustion engine, is charged, in order to compensate for stochastic reactions in the internal combustion engine, with a constant nominal voltage applied to a series circuit that includes a charge capacitor and a charge reversal capacitor, and it is discharged into the charge reversal capacitor to a prescribed voltage value. The remaining residual charge of the control element is charged into the charge capacitor via a limiter path.Type: ApplicationFiled: January 16, 2001Publication date: September 13, 2001Inventors: Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Christian Hoffmann, Richard Pirkl, Gunther Riedel
-
Patent number: 6271618Abstract: In a driving configuration for driving an actuator, component tolerances are compensated for by measuring a discharging current flowing in a measuring branch and the discharging voltage during a charge-transfer (reversing) operation. The measuring branch contains a series resonance circuit having a charging capacitor, a coil, an auxiliary switch and a measuring resistor. The current and voltage values measured at various instants are evaluated; and from them, initial parameters are determined for the subsequent driving operations.Type: GrantFiled: September 30, 1999Date of Patent: August 7, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken
-
Patent number: 6236190Abstract: A constant displacement ds of a capacitive actuator, for instance a capacitor for a fuel injection valve of an internal combustion engine, is obtained within a wide temperature range. While the actuator is being charged, its current and the voltage across the actuator are multiplied with one another. The product of the current and the voltage are integrated and the integration value is compared with a predetermined setpoint value. The process of charging is interrupted when the integration value reaches or exceeds the actual value. In an alternative embodiment, the actuator is charged from a constant current source and only the voltage drop is integrated.Type: GrantFiled: April 26, 1999Date of Patent: May 22, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken
-
Patent number: 6212053Abstract: The device drives one or more capacitive actuators with a control circuit. The device has a series circuit with a charging capacitor, a discharging capacitor, an electric coil, and the one or more actuators each with an associated selector switch. A discharging switch has a drain terminal connected to the node point between the two capacitors, and a source terminal connected via decoupling diodes to the drain terminals of the selector switches.Type: GrantFiled: December 6, 1999Date of Patent: April 3, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Richard Pirkl
-
Patent number: 6198199Abstract: A short circuit between a negative pole GND and a capacitive actuator in a circuit with a charging capacitor, a recharging capacitor, a recharging coil and a selector switch is determined by calculating a value corresponding to the quantity of charge QL flowing off from the recharging capacitor during a charging operation. The quantity of charge is compared with an integral of current i flowing during the charging operation via the selector switch assigned to the actuator. A short circuit of the actuator to the negative pole is diagnosed when the integral is smaller than k*QL (k<1).Type: GrantFiled: September 8, 1999Date of Patent: March 6, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Richard Pirkl
-
Patent number: 6191929Abstract: A control device includes a magnetic actuator, a final control element, a regulating unit and a measuring device. The magnetic actuator has a coil, a core, and an armature. The actuator is connected to the final control element. The measuring device determines an inductance value L of the coil and generates, as a function of the inductance value L, a first control signal by which a theoretical value of the amplitude of the current through the coil is changed to a holding value. When a pulse signal P is present, the current through the coil is regulated to the theoretical value by the regulating unit.Type: GrantFiled: August 13, 1998Date of Patent: February 20, 2001Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Richard Wimmer, Achim Koch
-
Patent number: 6157174Abstract: In a drive process of a capacitive control element, especially for a fuel injection valve, a charging of a capacitor having a stipulated voltage is transferred during a stipulated charging time, at least partially, to the control element. A deviation of energy transferred to the control element in the charging time from an experimentally determined curve of stipulated, constant energy for the entire temperature range of the control element is corrected in the subsequent drive processes incrementally by a characteristic mapping of the control element voltage and time.Type: GrantFiled: June 18, 1999Date of Patent: December 5, 2000Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Benno Larisch
-
Patent number: 6137208Abstract: A device and a method for driving at least one capacitive actuator, in particular a piezoelectrically operated fuel injection valve of an internal combustion engine, by a microprocessor-controlled control circuit. The device has a charging capacitor which can be recharged by an energy source, which charges the at least one actuator via switches controlled by the control circuit, and into which the actuator is discharged again.Type: GrantFiled: February 16, 1999Date of Patent: October 24, 2000Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Georg Brasseur, Hellmut Freudenberg, Hartmut Gerken, Richard Pirkl
-
Patent number: 6133714Abstract: A method of driving at least one capacitive actuator with a charge voltage. From a charge quantity .DELTA.Q supplied to the actuator and from the actuator voltage U.sub.p applied to the actuator after the charging operation is terminated, the actuator capacitance is calculated by the equation C.sub.p =.DELTA.Q/U.sub.p. From these values, the energy E.sub.actual =0.5*C.sub.p *U.sub.p.sup.2 =0.5*.DELTA.Q*U.sub.p is calculated. The charge voltage is regulated such that the energy actually supplied is equivalent to a specified desired value.Type: GrantFiled: December 6, 1999Date of Patent: October 17, 2000Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Manfred Weigl, Hartmut Gerken, Martin Hecker, Richard Pirkl
-
Patent number: 6121715Abstract: A capacitive control element is charged with a defined charging voltage Uc. From a stored mapping KF, the instantaneous control element capacitance Cp is determined from the charge voltage Uc and a control element voltage Up. In addition, energy E supplied to the control element is determined from the charge voltage Uc and the control element capacitance Cp. According to a deviation of energy E fed to the control element from a stipulated amount of energy Ev, the charge voltage Uc for a next drive process of the control element is regulated. The same process occurs for additional control elements.Type: GrantFiled: June 18, 1999Date of Patent: September 19, 2000Assignee: Siemens AktiengesellschaftInventors: Christian Hoffmann, Hellmut Freudenberg, Hartmut Gerken, Martin Hecker, Richard Pirkl