Apparatus for detecting displacement of electromagnetic actuator

Abstract

A displacement detecting apparatus of an electromagnetic actuator includes an electromagnetic actuator having a movable core, a drive coil and a detection coil, a drive portion for supplying a drive current to the drive coil on the basis of a pulse width modulation signal, and a displacement detecting portion to which an output voltage of the detection coil is inputted, for outputting a displacement detection signal, wherein the displacement detecting portion has a sampling-signal generating portion for generating a sampling signal in synchronism with the pulse width modulation signal, and a synchronous sampling portion for outputting the displacement detection signal by sampling the output voltage in synchronism with the sampling signal. Based on the displacement detecting apparatus, the electromagnetic actuator in a traditional structure is added with the detection coil so as to ensure high design freedom and compact structure of the displacement detecting apparatus.

Description

technical field

[0001] The invention relates to a displacement detection device of an electromagnetic actuator driven by a pulse width modulation signal. Electromagnetic actuators are used to generate a reaction force to the user's operation and to allow automatic operation of, for example, operating elements or members, valves and the like. Background technique

[0002] In the keyboard device of the electronic keyboard musical instrument, a drive mechanism is provided for each key to perform control of increasing or decreasing the touch feeling of the key felt by the performer or player during performance operation, that is, force sense control (force sense control), or as follows As described in Patent Document 1, automatic operation of keys is allowed without a player's operation to realize automatic performance. The keyboard device uses bidirectionally driven electromagnetic actuators. More specifically, in the electromagnetic actuator, a forward solenoid (forward coil...

Examples

Embodiment Construction

[0076] figure 1 is a functional block diagram illustrating a detection device for detecting displacement of an electromagnetic actuator according to an embodiment of the present invention. figure 1 The detection device generally indicated by 150 is composed of an electromagnetic actuator 1 , a drive part 2 and a displacement position detection part 3 . figure 1 The shown electromagnetic actuator 1 includes a movable core (movable iron core) 11 a and a drive coil 12 . The movable core 11a is formed of a magnetic material and is figure 2 A constituent element of plunger 11 is shown. The electromagnetic actuator 1 transmits a driving force generated by electromagnetic induction to a mechanically movable member 5 of a performance operating element such as a valve of an internal combustion engine or a key or pedal of an electronic keyboard instrument. The electromagnetic actuator 1 also includes a detection coil 13 .

[0077] The driving unit 2 displaces the movable core 11 a ...

technical field

[0001] The invention relates to a displacement detection device of an electromagnetic actuator driven by a pulse width modulation signal. Electromagnetic actuators are used to generate a reaction force to the user's operation and to allow automatic operation of, for example, operating elements or members, valves and the like. Background technique

[0002] In the keyboard device of the electronic keyboard musical instrument, a drive mechanism is provided for each key to perform control of increasing or decreasing the touch feeling of the key felt by the performer or player during performance operation, that is, force sense control (force sense control), or as follows As described in Patent Document 1, automatic operation of keys is allowed without a player's operation to realize automatic performance. The keyboard device uses bidirectionally driven electromagnetic actuators. More specifically, in the electromagnetic actuator, a forward solenoid (forward coil...

Examples

Embodiment Construction

[0076] figure 1 is a functional block diagram illustrating a detection device for detecting displacement of an electromagnetic actuator according to an embodiment of the present invention. figure 1 The detection device generally indicated by 150 is composed of an electromagnetic actuator 1 , a drive part 2 and a displacement position detection part 3 . figure 1 The shown electromagnetic actuator 1 includes a movable core (movable iron core) 11 a and a drive coil 12 . The movable core 11a is formed of a magnetic material and is figure 2 A constituent element of plunger 11 is shown. The electromagnetic actuator 1 transmits a driving force generated by electromagnetic induction to a mechanically movable member 5 of a performance operating element such as a valve of an internal combustion engine or a key or pedal of an electronic keyboard instrument. The electromagnetic actuator 1 also includes a detection coil 13 .

[0077] The driving unit 2 displaces the movable core 11 a ...

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