Magnetic attraction driving engine using permanent magnet

Abstract: A magnetic attraction driving engine utilizing a permanent magnet is provided with a permanent magnet, an electromagnet formed by winding a coil on a magnetic core with one end thereof stuck to one magnetic pole end of the permanent magnet, an excitation controller for exciting the electromagnet to change a state of magnetic fluxes in the vicinity of the magnetic pole end of the permanent magnet, a movable member having magnetic attractivity set in the vicinity of the magnetic pole end of the permanent magnet by being supported and guided so as to be capable of coming close to or separating away from the permanent magnet and a returning force applying member for causing by pressure the movable member to retreat against a magnetic attracting force and move back and forth by changing a magnetic attracting force of the permanent magnet.

Description: Background of the Invention Field of the Invention The present invention relates to a magnetic attraction driving engine for converting electrical energy into kinetic energy by utilizing a permanent magnet. Prior Art Conventionally, various energy converters utilizing permanent magnets haue been used. Typical of those which convert electrical energy into kinetic energy is a motor. In the case of a DC motor, a DC current is caused to flow to the coil of a rotor placed in a magnetic field generated by a permanent magnet and the rotor is rotary-driven by working with a magnetic field thus generated. In an AC synchronizing motor or an AC inductive motor which has also been conventionally used, an exciting current is caused to flow by applying an AC voltage to an exciting coil provided in a magnetic pole of a stator with a required phase difference to generate a rotating magnetic field, and a rotor is rotated by being synchronized therewith. In the case of a linear motor, likewise, an exciting current is caused to flow by applying an AC voltage to a number of linearly arrayed exciting coils with a required phase difference, a straight advance magnetic field is generated and a propelling power is imparted to a magnetic movable body. However, the energy converters of these conventional types, represented by the above-described DC motor, are not structured to directly extract magnetic energy possessed by a permanent magnet to the outside and thus the energy converting efficiency thereof is relatively low. Furthermore, a driving engine having an electromagnet and a permanent magnet is known from the EP 0 252 402 A1. The driving engine disclosed therein also uses the magnetic energy of an electromagnet to move a movable member back and forth. As described above, this leads to a relatively low energy converting efficiency. Finally, DE 34 10 596 A1 discloses an electromagnetic leakage current switch comprising an electromagnet and a permanent magnet. The electromagnetic switch does not provoke an active, controlled driving movement of a movable member. It rather works passively and reacts on non-permissible variations of a current flowing through a coil of the electromagnet. Moreover the electromagnetic switch also uses the magnetic energy of the electromagnet to move the movable member back and forth. Summary of the Invention The present invention was made in view of the above-described problems, and it is an object of the invention to provide a new magnetic attraction driving engine directly utilizing the magnetic energy of a permanent magnet. The invention is designed to intermittently or continuously extract the required mechanical energy from a permanent magnet by using an electromagnet as a means for switching magnetic fluxes from the permanent magnet when mechanical energy is to be made by utilizing the permanent magnet. More specifically, a magnetic attraction driving engine utilizing a permanent magnet provided by the invention is characterized in the following way: The magnetic attraction driving engine according to the invention is defined in claim 1. The dependent claims describe particular embodiments of the invention. The magnetic attraction driving engine comprises a permanent magnet. Furthermore, it is provided with an electromagnet formed by winding a coil around a magnetic core. One end of the magnetic core is closely adhered to one magnetic pole end of the permanent magnet. An excitation controller for exciting the electromagnet is connected to the electromagnet. By exciting the electromagnet the direction of a magnetic flux in the electromagnet is alternated. Thereby, a state of a magnetic flux in the vicinity of the magnetic pole end of the permanent magnet is changed. A movable member having magnetic attraction is disposed in the vicinity of the magnetic pole end of the permanent magnet. The movable member is supported and guided to be capable of approaching close to or separating away from the magnetic pole end of the permanent magnet. Finally, there is a returning force applying member for generating a required returning force by pressure in a direction in which the movable member is moved away from the permanent magnet and thereby causing the movable member to retreat back. In this way, the movable member can be moved back by means of a magnetic attracting force of the permanent magnet and forth by means of the returning force of the returning force applying member. A coil which is part of the electromagnet can be made of normal electrically conductive wire, using such generally known materials as copper, aluminum and others. However, a superconductive magnet made of a superconductive material may be adopted. Moreover needless to say, a single coil can be used or two coils independent of each other can be provided in the magnetic core. In a case where the electromagnet is strucured by using a single coil, switching of magnetic polarity in one end of the magnetic core can be performed by supplying, for instance, a rectangular wave signal from the excitation controller to the single coil. As a result, it is possible to change the condition of magnetic fluxes in the vicinity of one magnetic pole end of the permanent magnet. On the other hand, in case where two coils independent of each other are wound an the magnetic core, the excitation controller can be structured so as to be capable of switching magnetic polarity in one end of the nagnetic core by alternately switching supplying of a current between one coil and the other. As a magnetic material of the movable body, such generally known ones as iron, nickel, ferrite and others can be used. However, it is possible to obtain required nagnetic attractivity by integrating a magnetic member into a nonmagnetic member formed of aluminum, plastic or the like. When the exciting condition of the electromagnet is controlled by the excitation controller, magnetic polarity in one end of the magnetic core closely adhered to one end of the permanent magnet changes and thus density of magnetic fluxes in the vicinity of one magnetic pole end thereof is caused to change. As a result, magnetic attraction between the movable member and the permanent magnet changes, making it possible to move the movable body back and forth by cooperatively working with the returning force applying member. In a magnetic attraction driving engine of the invention, it is possible by means of the above-described driving principle to utilize magnetic fluxes formed from magnetic poles of a permanent magnet as mechanical energy in a state where supplying of energy from an outside system is shut off. It is also possible to expect a great deal of energy switching efficiency since an input from a DC power source necessary for this to function as a driving engine works in the same way as electricity supplied to an ignition plug in a gasoline engine and only an extremely small amount of this input is necessary for a generated driving power. Moreover, as a structure for taking out mechanical energy, one of a back and forth movement engine can be utilized and thus losses in a movement system caused by frictions can be reduced to a practical level. Brief Description of the Drawings Other features and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings wherein: Fig. 1 is a structural view showing a magnetic attraction driving engine utilizing a permanent magnet in a first preferred embodiment; and Fig. 2 is a structural view showing a magnetic attraction driving engine utilizing a permanent magnet in a second preferred embodiment; Detailed Description of the Preferred Embodiments First Preferred Embodiment Fig. 1 shows a prime mover structured by using a magnetic attraction driving engine which utilizes a permanent magnet in a first preferred embodiment of the invention. This prime mover 10 transmits hack and forth movement energy obtained firom a magnetic attraction driving engine 20 structured according to the invention to a puri 12 by using a crank shaft 11 and in this way rotary motion is taken out by rotating the puri 12. First, explanation will be made of a structure of the magnetic attraction driving engine 20. In Fig. 1, a sign 21 indicates a fixed frame made of a rigid nonmagnetic material such as brass and the like, and a sign 22 indicates a permanent magnet fixed in a first arm 21A of the fixed frame 21 by proper means of bolts, etc. In the embodiment, an axial line of the permanent magnet 22 is extended roughly horizontally to a base part 21 C of the fixed frame 21 and S magnetic pole end 22A thereof is fixed in the first arm 21A. An electromagnet 23 is provided between an N magnetic pole end 22B which is a free end of the permanent magnet 22 and the base part 21 C. The electromagnet 23 is composed of a magnetic core 24 and a coil 25 wound thereon and the coil 25 indudes two exciting coils 25A and 25B. In the embodiment, an axial line of the magnetic core 24 is roughly perpendicular to that of the permanent magnet 22, one end surface 24A of the magnetic core member 24 is closely adhered to a side surface of the N magnetic pole end 22B of the permanent magnet 22 and the electromagnet 23 is fixed in the fixed frame 21 by proper means of bolts, etc. The magnetic core member 24 can be structured as a bar-shaped member of iron, nickel, ferrite or permalloy or a thin plate laminated body made of these. In the electromagnet 23, an excitation control unit 26 is provided for exciting the electromagnet 23 so as to cyclically change a condition of magnetic fluxes in the vicinity of the N magnetic pole end 22B of the permanent magnet. The excitation control unit 26 is provided with a battery 27 as a DC power source, a negative electrode of the battery 27 is connected to each end of the exciting coils 25A and 25B and positive electrode thereof is connected to the other end of the exciting coils 25A and 25B via a relay contact circuit 28. A relay contact point 28A of the relay contact circuit 28 is structured as an always closed contact point while another relay contact point 28B is structured as an always opened contact point. To a relay coil 29 for switching ON/OFF both relay contact points 28A and 28B a pulse voltage P of a specified constant frequency is applied from a pulse generator 30. A cycle of the pulse voltage P is set so as not to exceed a response speed for operation of the contact points 28A and 28B by the relay coil 29 and in response to changes in a level of the pulse voltage P the relay contact points 28A and 28B are alternately closed. As a result, exciting currents IA and IB are caused to flow to the exciting coils 25A and 25B. A direction for winding the exciting coil 25A is reverse to that for the exciting coil 25B, and when the exciting current IA flows to the exciting coil 25A, an N magnetic pole is generated on one end surface 24A of the magnetic core 24, and when the exciting current IB flows to the exciting coil 25B, an S magnetic pole is generated on one end surface thereof. As a result, in case where an S magnetic pole is generated on one end surface 24A of the electromagnet 23, leakage of magnetic fluxes from the N magnetic pole end 22B of the permanent magnet 22 is extremely small thanks to closely adhered arrangement of the permanent magnet 22 and the electromagnet 23, most of the fluxes return through the magnetic core 24 to the S magnetic pole end thereof and thus the number of those going out of the N magnetic pole end 22B is extremely small (hereinafter, this is called "a state of magnetic flux OFF"). Conversely, in case where an N magnetic pole is generated on one end surface 24A of the electromagnet 23, no magnetic fluxes from the magnetic pole end 22B of the permanent magnet 22 pass through the magnetic core 24 and thus a condition of magnetic fluxes in the vicinity of the N magnetic pole end 22B is the same as that in case where no electromagnet 23 is provided (hereinafter, this is called "a state of magnetic flux ON"). Therefore, in accordance with changes in a level of the pulse voltage P, a condition of magnetic fluxes, that is, density of magnetic fluxes, in the vicinity of the N magnetic pole end 22B of the permanent magnet 22 changes. In order to transform a change in the density of magnetic fluxes into an electromagnet attracting force and take this out as mechanical energy, a movable member 31 is provided in the vicinity of the N magnetic pole end 22B. In the embodiment, as shown in the drawing, the movable member 31 is formed of iron which is a magnetic material so as to provide magnetic attractivity and guiding rollers 32A and 33A on an upper end of supporting legs 32 and 33 vertically provided in the fixed frame 21 are freely slidably engaged with and fitted into a supporting and guiding groove 31A formed in the movable member 31. Thus, the movable member 31 is supported by the supporting legs 32 and 33 so that axial line thereof is roughly parallel to that of the permanet magnet 22 and this is also guided so as to capable of moving back and forth in a direction of axial line thereof. Furthermore, in case where a movable member 31 is made of both nonmagnetic and magnetic members (this can also be structured to obtain required magnetic attractivity by means of the magnetic member), it is preferable for the movable member 31 to be strutured so that the magnetic member is placed as close as possible to the permanent magnet. A contracting coil spring 34 is provided between the movable member 31 and a second arm 21B of the fixed frame 21. The contracting coil spring 34 is used to give a required returning force for pull the movable member away from the permanent magnet 22 so as to allow the movable member 31 to move back and forth thereto in accordance with a change in a magnetic attracting force worked between the movable member 31 and the permanent magnet 22. A force of the contracting coil spring 34 allows, in a state of magnetic flux ON, the movable nember 31 to move in a direction of an arrow X by means of a magnetic attracting force of the permanet nagnet 22. In a stete of magnetic flux OFF, on the other hand, this allows the movable member 31 to be fully pulled back in a direction of an arrow Y. Instead of the contracting coil spring, it is possile to use a plate spring, a natural or a synthetic rubber member, or an appropriate elastic member. A supporter 35 is fixed in an upper part of the movable member 31, one end of a crank shaft 10 is pivotally supported on the supporter and other end thereof is pivotally attached to the vicinity of an outer peripheral edge of the puri 12 axially provided freely rotatably in a supporter 36 fixed in the first arm 21A. In the prime mover 10 shown in Fig. 1, in the exciting control unit 26, when a pair of relay contact points 28A and 28B are alternately closed in response to a pulse voltage P exciting currents IA and IB are alternately supplied from the battery 27 to the exciting coils 25A and 25B and N and S magnetic poles are alternately generated on one end surface 24A of the exciting member 24. When an S magnetic pole is generated on one end surface 24A, magnetic fluxes from the N magnetic pole end 22B of the permanent magnet 22 return through the magnetic core 24 to the S magnetic pole end 22A without going toward the movable member 31. That is, a state of magnetic flux OFF is generated, no big magnetic attracting forces work between the permanent magnet 22 and the movabel member 31 is fully pulled back in a direction of an arrow Y by a contraction elastic force of the contracting coil spring 34. On the other hand, when an N magnetic pole is generated on one end surface 24A, magnetic fluxes from the N magnetic pole end 22B of the permanent magnet go toward an oppositely placed movable member together with those from the electromagnet 23, since these cannot go through the magnetic core 24 closely adhered thereto. That is, a state of magnetic flux ON is generated, a big magnetic attracting force works between the permanent magnet 22 and the movable member 31 and the movable member 31 is fully moved in a direction of an arrow X against a contracting elastic force of the contracting coil spring 34. In short, if no magnetic fluxes from the permanent magnet 22 are caused to go through the magnetic core 24 by actively forming an N magnetic pole an one end surface 24A, no leakage of magnetic fluxes occurs because most of those from the permanent magnet 22 go through the movable member 31, thereby improving efficiency. As clear from the above description, polarities of magnetic poles generated on one end surface 24A of the electromagnet 23 are alternately switched between N and S and thus the movable member 31 is caused to move back and forth cooperatively with the contracting coil spring 34 making it possible to obtain a rotational output from the puri 12. Here, since the number of magnetic fluxes Φ to determine strength of the electromagnet 23 necessary for switching magnetic fluxes from the permanent magnet 22 is proportional to a product between a winding number N of a coil thereof and a current I flowing thereto, the following expression is obtained: Φ = k N I A value of the number of magnetic fluxes Φ necessary for ON/OFF switching of the magnetic fluxes is set at specified constant one and thus a value of an exciting current I can be made small if the winding number N of a coil of the electromagnet is set large. DC energy supplied to the electromagnet 23 is V x I if an output voltage of the battery 28 is V and thus supplied DC energy can be reduced if a value of I is set small and the device can be actuated highly efficiently. Furthermore, in the description of the first preferred embodiment, reference was made to case where a usual electromagnet is used. It is needless to say, however, that efficiency can be further improved if superconductive electromagnets 31, 32,... 36 are used. One of magnetic poles of the permanent magnet 22 opposite to the movable member 31 was an N magnetic pole in the above-described embodiment. However, an S magnetic pole may be used for this. Moreover, it is not always necessary to set directions for winding the exciting coils 25A and 25B of the electromagnet reverse to each other and the same effect as in the case of the embodiment can be obtained by setting reverse directions for supplying currents to both exciting coils 25A and 25B. Second Preferred Embodiment Fig. 2 shows a prime mover structured by using a magnetic attraction driving engine which utilizes a permanent magnet in a second preferred embodiment of the invention. A device indicated by a sign 40 is an air compressor utilizing back and forth movement at it is obtained by a magnetic attraction driving engine 50 provided by the invention. In the magnetic attraction driving engine 50, a permanent magnet and an electromagnet 53 having a coil 55 wound thereon are attached to a fixed frame 51 made of a nonmagnetic material as shown in Fig. 2, this attachment is basically the same as in the case of the first embodiment and thus explanation thereof will be omitted. A coil 55 of the electromagnet 53 is a single coil and connected to an excitation control unit 56 for controlling excitation of the electromagnet 53. The excitation control unit 56 is provided with an inverter 57 capable of receiving AC power supplied from an AC power source 57 and outputting an AC rectangular wave voltage E of 0 to 60 [Hz]. In this preferred embodiment, an AC rectangular wave voltage E is outputted from the inverter 58 and applied to the coil member 55. Therefore, N and S magnetic poles are generated on one end surface 54A of a magnetic core 54 of the electromagnet 53 in accordance with a cycle of this AC rectangular wave voltage E and thereby density of magnetic fluxes in the vicinity of an N magnetic pole end 52B of the permanent magnet 52 is caused to change based on the same principle as in the case of the first embodiment. In the vicinity of the N magnetic pole end 52B of the permanent magnet 52, a movable member 59 made of iron which is a magnetic material is provided. The movable member 59 is stuck to a free end of a rod 62A of a piston 62 slidably provided in an air cylinder 61 supported and fixed by second and third arms 51B and 51C of the fixed frame 51. An airtight state is maintained beween an outer peripheral surface 62B of the piston 62 and an inner wall surface 61A of the air cylinder 61 and a pressurizing chamber 61B is plotted in the air cylinder 61. In the air cylinder 61, an air intake valve 63 for introducing air from the air pressurizing chamber 61A and a check valve 65 for discharging compressed air pressurized in the air cylinder 61 to an output pipe 64 are provided including a generally known air pressurizing device 70. In the air pressurizing device 70, outside air is introduced from the air intake valve 63 into the pressurizing chamber 61B when the piston 62 moves in a direction of an arrow A, intaken air is pressurized in the pressurizing chamber 61B when the piston 62 moves in a drection of an arrow B, and when pressurizing force thereof exceeds a specified value, the check valve 65 is opened and the air is compressed and discharged to the output pipe 64. In order to obtain back and forth movement of the piston 62 necessary for intaking and compressing air by means of the magnetic attraction driving engine 50, the movable member 59 is directly connected to the piston 62. A contracting coil spring 60 is provided between the movable member 59 and the air cylinder 61 and a rerturning force is given to pull back the movable member 59 in a direction of an arrow B by an elastic contracting force of the contracting coil spring 60. According to the above-described structure, by alternately generating S and N magnetic poles on one end surface 54A of the electromagnet 53, as in the case of the first embodiment shown in Fig. 1, the movable member 59 is caused to move back and forth at the same cycle as that of an AC rectangular wave voltage E by intermittently generated magnetic attracting forces of the permanent magnet 52 and returning forces of the contracting spring 60 and thus the piston 62 can be moved back and forth. As a result, an air compressor 40 can take compressed air out of the output pipe 64 by excitation control of the electromagnet device 52 using an AC rectangular wave voltage E from the excitation control unit 56. A pump can be structured in the same way as the air compressor shown in Fig. 2.

Claims: Magnetic attraction driving engine (10; 40) utilizing a permanent magnet comprising: a permanent magnet (22; 52); an electromagnet (23; 53) formed by winding a coil (25; 55) around a magnetic core (24; 54) provided with one end (24A; 54A) thereof adhered to one magnetic pole end (22A, 22B; 52B) of said no under-lining in claim 1 permanent magnet (22; 52); an excitation controller (26; 56) for exciting said electromagnet (23; 53) in order to alternate the direction of a magnetic flux in said electromagnet (23; 53) and to thereby change a state of a magnetic flux in the vicinity of said magnetic pole end (22A, 22B; 52B) of said permanent magnet (22; 52); a movable member (31; 59) having magnetic attraction, disposed in the vicinity of said magnetic pole end (22A, 22B; 52B) of said permanent magnet (22; 52) by being supported and guided to be capable of approaching close to or separating away from said magnetic pole end (22A, 22B; 52B) of said permanent magnet (22; 52); and a returning force applying member (34; 60) for causing by pressure the movable member (31; 59) to retreat and move back and forth against a magnetic attracting force by means of changes in a magnetic attracting force of said permanent magnet (22; 52). Driving engine (10; 40) according to claim 1, characterized in that a rectangular wave signal from the excitation controller (26) is caused to flow through said coil (25). Driving engine (10; 40) according to claim 1, characterized in that said coil (25) includes two exciting coils (25A, 25B) wound in opposite directions around said magnetic core (24) and that exciting currents (IA, IB) with the same direction are caused to flow alternately through said exciting coils (25A, 25B). Driving engine (10; 40) according to claim 1, characterized in that said coil (25) includes two exciting coils (25A, 25B) wound in the same direction around said magnetic core (24) and that exciting currents (IA, IB) with opposite directions are caused to flow alternately through said exciting coils (25A, 25B) .

Inventors: ASAOKA KEIICHIRO, OGINO SANSHIRO, ASAOKA, KEIICHIRO, OGINO, SANSHIRO
Applicants: ASAOKA KEIICHIRO, OGINO SANSHIRO, ASAOKA, KEIICHIRO, OGINO, SANSHIRO
Application year: 1995
Main classification: H01F7
IPC codes: H02K37, H02K21, H01F7, H02K25, H02K33, H02K29