EP0184940A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
A method of controlling electromagnetic actuators and a controller therefor
Assignee: Kawasaki Motors Ltd
•
Filing: 1985-12-12
•
Granted: —
•
Expires: 2005-12-12
Abstract
Abstract An electromagnet device has a pair of electromagnets (10a, 10b) and a movable body (13, 13a, 16) movable by alternately switching the electromagnetic forces thereof. A controller (20, 21) for the device has a drive circuit (20) with switches (QL1, QL2, QR1, QR2) controlled by control means (21) which receives a command signal which initiates displacement of the body and current reference values. Comparators (CM1, CM2) compare these reference values with currents flowing throughthe coils (SR, SL) of the electromagnets. The control means (21) functions to cause the drive circuit (20) to supply current to both coils (SR, SL) of the electromagnets to maintain the movable body in an electromagnetically held state. When a first of the coils (SR) is in a state of holding the movable body the control means causes a current (IH) to be supplied to the first coil (SR) to maintain the holding state and causes a pre-energising current (IE) to be supplied to the second coil (SL). When the command signal signifies the body is to be displaced the holding current in the first coil (SR) maintaining the holding state is suddenly reduced.
Inventors
- 👤 Osamu Nagata
- 👤 Toshiharu Ozaki
- 👤 Takashi Kajima
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 23:55
CPC Classifications
F; F02; F02D; F02D41/00; F02D41/20; H; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/04113; H03K17/51; H03K17/56; H03K17/60; H03K17/64; F02D2041/2017; F02D2041/202; F02D2041/2024; F02D2041/2027; F02D2041/2044; F02D2041/2058; F02D2041/2068; F02D2041/2079
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
132 words
A controller for use with an electromagnetic device of the type employing a pair of electromagnetic coils (SL, SR) and a body (13, 16) movable in relation to the coils; said controller comprising drive means (20) with switches (QRl, QR2, QL1, QL2) for establishing current paths through the coils (SR, SL) in response to a change-over command signal to move the body between first and second positions and control means (21) for controlling the drive means to supply energising currents of different levels to both the first and second coils (SR, SL) to maintain the body (13, 16) in a first position and which responds to the command signal to decrease the current in the first coil (SR) rapidly to effect the movement of the body (13, 16) to the second position.
Claim 2
Dependent Claim
132 words
A controller for use with an electromagnetic device of the type employing a pair of electromagnetic coils (SL, SR) and a body (13, 16) movable in relation to the coils; said controller comprising drive means (20) with switches (QRl, QR2, QL1, QL2) for establishing current paths through the coils (SR, SL) in response to a change-over command signal to move the body between first and second positions and control means (21) for controlling the drive means to supply energising currents of different levels to both the first and second coils (SR, SL) to maintain the body (13, 16) in a first position and which responds to the command signal to decrease the current in the first coil (SR) rapidly to effect the movement of the body (13, 16) to the second position.
Claim 3
Dependent Claim
41 words
A controller according to claim 1, wherein the control means (21) also serves to increase the current in the second coil (SL) in response to the command signal to effect the movement of the body (13, 16) to the second position.
Claim 4
Dependent Claim
59 words
A controller according to claim 1 or 2, wherein there is provided a series circuit in parallel with each coil (SR, SL), each series circuit comprising a diode (CR1, L12) with opposite polarity to that of the coil energising current and a non-linear device (ZDR, ZDL) which conducts when the back e.m.f. in the coil exceeds a pre-determined value.
Claim 5
Dependent Claim
24 words
A controller according to claim 1, 2 or 3, wherein the drive means (20) provides chopped mode energising currents to the coils (SR, SL).
Claim 6
Dependent Claim
62 words
A controller according to any one of claims 1 to 4, wherein the control means (21) includes comparators (CM1, CM2) receiving inputs representing the currents through the coils (SR, SL) and current reference values (IE, IH), timers (TM1, TM2) for providing time-delayed signals and a series of logic gates which serves to control the operation of the switches (QR1, QL1, QR2, QL2).
Claim 7
Dependent Claim
37 words
A controller according to claim 5, wherein the control means (21) further comprises switches (SW1, SW2) which respond to the command signal to input the current reference values to one or other of the comparators (CM1, CM2).
Claim 8
Dependent Claim
38 words
A controller according to claim 5 or 6, wherein the control means (21) further comprises an edge detector (ED) for detecting changes in the command signal and for enabling the timers (TM1, TM2) in response to such changes.
Claim 9
Dependent Claim
26 words
A controller according to claim 1, wherein the control means (21) serves to increase the current in the first coil (SR) prior to its rapid decrease.
Claim 10
Independent Claim
78 words
A method of controlling an electromagnetic device of the type employing a pair of electromagnetic coils and a body movable by energising the coils; said method comprising supplying current to a first coil to hold the body in a first position and, in order to move the body to a second position, supplying current to a second coil prior to the movement while maintaining the current supply to the first coil and the de-energising the first coil rapidly.
Claim 11
Independent Claim
78 words
A method of controlling an electromagnetic device of the type employing a pair of electromagnetic coils and a body movable by energising the coils; said method comprising supplying current to a first coil to hold the body in a first position and, in order to move the body to a second position, supplying current to a second coil prior to the movement while maintaining the current supply to the first coil and the de-energising the first coil rapidly.
Claim 12
Dependent Claim
27 words
A method according to claim 9, and further comprising prior to the movement and then de-energisation of the first coil, increasing the current in the first coil.
Claim 13
Dependent Claim
27 words
A method according to claim 9, and further comprising increasing the current in the second coil to effect the movement of the body to the second position.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.