A magneto electric generator rotor

Abstract: By inserting a male screw for fixing a ratchet claw into a nut placed on an insert core and the like to prevent rotation, it is possible to eliminate additional screw processing on the insert core, to increase magnetic resistance between a magnet (6) and the insert core provided with the former, to concentrate irradiation of magnetic flux from the second magnet pole toward outside and to fix the magnet and the second magnet pole onto the insert core with screws. Further, by tapering an axial hole of the rotor, it is possible to easily and accurately attach the insert core or the rotor to a crankshaft. Furthermore, by inserting a removal part of a removal tool into a perforation hole of the rotor, it is possible to realize quick and simple removal of the rotor from the crankshaft.

Description: This invention relates to a magneto electric generator rotor used in an internal combustion engine spark plug (see US-A-5 118 978). Figs 5 and 6 show a broken down section of a small size engine used in a conventional operating machine. In said figures numeral 1 is a small size engine, 12 is a cylinder for said engine 1, and 13 is a conrod supporting a piston that moves in this cylinder 12. Also, 14 is a crankshaft for eccentric driving the end of said conrod 13, and 15 is a nut to fix rotor B attached to the end of this crankshaft 14. One side of said rotor B, that is on the opposite side of an axial hole part through which the crankshaft 14 is inserted, secures a magnet 2 and forms a pole piece part P together with a magnetic pole 3, while the other side is composed of an insert core 26 of a ferromagnetic material that becomes counterweight part 4. Further, a cooling fan and the like is installed to this insert core 26 to form one body. Numeral 6 is a non-magnetic material layer such as a synthetic resin layer formed in a discoidal shape so as to cover said insert core 26. On one hand 7 is a ratchet claw which is supported in a freely revolving manner to an axle part 8 having a hole 8a as a cylinder part. Also, as shown in Fig. 46, a male screw 10 is inserted through this axle part 8. and the tip of this male screw 10 is screwed into and fixed to female screw 27 which has been formed beforehand in said insert core 26. Numeral 9 is a ratchet spring of which one end is fixed to said axle part 8, and the other end is fixed to said ratchet claw 7 and this gives a rotating force in one direction to the ratchet claw 7. Also, a reel axle 29 is provided in one body so as to project into an operating machine frame 28 opposite to said rotor B. A reel 16 having continuously wound thereon a rope 17 is supported on this reel axle 29 in a freely rotating manner. On to this reel 16 provided with an engagement part 30 which catches said ratchet claw 7 and gives an rotating force to the reel 16. A spiral spring 18 is installed in the periphery of said reel axle 29 to apply to said reel 16 a rotating force around this reel axle 29. 31 is a washer fixed to the end of the reel axle 29 by a screw 32 and serves as a protector to prevent the axle hole of the reel 16 from coming off of the reel axle 29. Moreover, the reel axle 29, the reel 16, the rope 17, the spiral spring 18, the engagement part 30, the ratchet claw 7 and the like form a recoil starter. Also, 19 is a coil unit formed a power generating coil, ignition coil, ignition control circuit and the like in one body with thermosetting or thermoplastic synthetic resin and is fixed to said cylinder 12 side. 20 is a plug cap connected to said coil unit 19 through a cable 33. This plug cap 20 is connected to a plug 21 next to the cylinder 12. 28 is the operating machine frame housing an engine. In a small size engine made of such a construction, the reel 16 rotates by manually pulling the rope 17 wound on this reel 16, and the engagement part 30 installed on said reel 16 catches on the ratchet claw 7 on rotor B which has a magnet 2 buried in the insert core 26, and rotates rotor B. In this way, because said rotor B is attached to the crankshaft 14 of the engine 1, the crankshaft 14 is driven to rotate by said rotor B and the engine 1 is cranked up. On one hand, at that time the magnetic flux of the magnet 2 attached to said rotor B interlinks with the coil unit 19 having an ignition control circuit fixed to the cylinder 12 side of said engine 1. Said coil unit 16 will thus generate a power output, and this power output will be supplied to the ignition plug 2 through the cable 33 and the plug cap 20, and by this, the ignition plug 21 will generate a spark, ignite the gas mixture in the cylinder 12, and start up the engine 1. Further, the fixing of the ratchet claw 7 described previously is done by screwing in the axle part 8 supporting it in a rotatable manner to the insert core 26 of the male screw 10. For this reason the female screw 27 conforming to the male screw 10 is machine tooled as aforementioned in the said rotor B. On one hand, the rotor shown in Figs. 7 and 8 has been proposed in the past as a rotor used in a magnetic power generating machine such as the one described above. This rotor B1 is a rotor having a hole piece part 44 with a magnet 42 on one side and an insert core 41 as a counterweight part 45 on the opposite side of an axial hole part 43 buried as an insert form within a synthetic resin (not shown). This rotor B1 is described in, for example Japanese Utility Model Publication 1993-10526. In this conventional rotor B1, the insert core 41 has been made into an integrated unit with a rivet 47 riveting together layers of multiple magnetic plates in multiple locations, and said axial hole part 43 is a straight hole with the diameter being equal in the direction of the axle. Also, of the three magnetic poles 46,46a and 46b forming the pole piece 44, said magnet 42 is inserted in an open hole 49 formed in the center magnetic pole 46, and both ends of the magnet protrude outward towards the axial fringe of each magnet pole 46,46a and 46b. In such insert core 41, the pole piece part 44 and the counterweight part 45 are formed in one body, and because there is no need for assembly work and machine tooling after die casting the advantage of a relatively low cost is achieved. However, with a rotor B of a conventional magnetic power generator such as that shown in Figs. 5 and 6, even at present when the non-processing of the rotor B has become advanced, but only the processing of the screw (female screw) 27, which is used for fixing said ratchet claw 7, cannot be eliminated. For this reason a reduction in cost could not be achieved. Also, with a rotor using an insert core of layered magnetic plates and formed into an approximately circular shape with plastic, the processing of said screw for use in attaching the ratchet could not be carried out without performing special work such as inserting aluminum parts. In a magnetic power generator rotor of this invention, a nut rotation blocking hole and an insert hole for said male screw are provided on a part of the insert core to which a rotation ratchet claw is fixed, whereby there is no need for a screw thread processing on this insert core itself latter, and said ratchet claw can be fixed to the insert core through an axial part supporting in freely rotating manner said ratchet claw by merely fastening said nut to said rotation blocking hole and screwing the tip of the male screw, which had been passed through said perforation. In addition, by forming the axial part supporting said ratchet claw in a manner enabling rotation in one body with said insert core during the formation of said insert core, it is not necessary to use a cylindrical part forming said axial part as a part and therefore lowering of costs can be planned. In the accompanying drawings:- Fig. 1 is a sectional drawing showing a partly broken down small size engine having a magnetic power generator rotor in accordance with the configuration for implementing this invention. Fig. 2 is a sectional drawing showing an enlargement of the principal parts of the rotor in Fig. 1. Fig. 3 is a left side view showing the principal parts of the rotor in Fig. 2. Fig. 4 is a sectional drawing showing an enlargement of the principal parts of a magnetic power generator rotor according to another configuration for implementing this invention. Fig. 5 is a sectional view showing a partially broken down conventional small size engine. Fig. 6 is a sectional view showing an enlargement of part of the rotor in Fig. 5. Fig. 7 is a dismantled view showing an insert core in a conventional magnetic power generator rotor. Fig. 8 is a longitudinal section view of the insert core shown in Fig. 7. In Figs. 1 and 2, identical symbols indicated previously are affixed to the parts identical with the past examples in Figs. 45 and 46. In rotor A of the magnetic power generator of the configuration according to this implementation, a ratchet claw 7 is provided as shown in Fig. 2 to an axial part 8 having a perforation 8a as it cylindrical part. Moreover, 10 is a male screw pushed through a perforation 23 which is formed by a perforation 8a of said axial part 8 and an insert core 5. Furthermore, 11 is a nut which is screwed on the end of said male screw 10 and secures said axial part 8 to said insert core 5. Moreover, nut 11 is located in a rotation blocking hole 24 formed in said insert core 5, and blocks rotation despite the screwing in operation of said male screw 10. Fig. 3 shows a hexagonal concave shape slightly larger than said nut 11. Also, said rotation blocking hole 24 can be formed with a non magnetic layer 6 such as synthetic resin and aluminum without providing an insert core 5. Consequently, in the rotor of a small size engine with such a construction, in case said ratchet claw 7 is installed on the insert core 5, first the ratchet claw 7 is attached to said axial part 8 in a freely rotating manner, then the male screw 10 is screwed through the axial part 8. Next, after inserting said male screw 10 into the perforation 23 which has been pre-formed in the insert core 5, the nut 11 is screwed on to the end of said male screw 10 which is protruding out from the insert core 5. Said screwing on action can be easily and quickly effected by screwing on the male screw 10 to the nut 11, which has been installed in the rotation blocking hole 24, through the axial part 8. Therefore, according to the configuration of this embodiment, there is no need to purposely carry out the screw thread process for the male screw in order to screw the male screw 10 on to the insert core 5 and said ratchet claw 7 can be easily secured. Further, according to the configuration of this embodiment, the shape of said rotation blocking hole 24 is shown as being hexagonal, but it can be any shape if the rotation blocking effect can be achieved when the nut 11 is embedded. Next, Fig. 4 is a partial sectional view showing another configuration for implementing this invention, and the difference with the above described embodiment is in the point that the axial part 8 supporting the ratchet claw 7 in a free rotating manner has been formed into one unit with the insert core 5 when forming the latter. In all other respects it is identical with the embodiment described above, so a duplication of explanation will be omitted. With such a construction, the need to prepare said axial part 8 as a separate part will disappear, and it will be possible to plan a cost reduction by eliminating the number of parts used, and an improvement in the efficiency of assembly work. Further, in the configuration for implementation shown in Figs. 1 through 4, an insert core 5 formed by using a tempered bonding metal of a magnetic material was shown, but a layered magnetic plate would also have the same effect as that described previously. Moreover, in said configuration for implementation, the case where an insert core 5 is covered with a synthetic resin layer that is of a non-magnetic material and formed into a disc shape was described; however, as long as it is a non-magnetic material, anything can be used. For example, it can be covered with an aluminum die cast using aluminum. Furthermore, said configuration for implementation explained the case where an insert core 5 was used with the axial hole between a pole piece part P on one side and a counterweight part 4 on the other side; however it goes without saying that the present invention can also be applied when the pole piece part P and the counterweight part 4 are separated. It will thus be seen that the present invention, at least in its preferred forms, provides an inexpensive magnetic power generator rotor on which a claw can be easily and reliably attached without any special workmanship or screw processing.

Claims: A magneto electric generator rotor comprising an insert core (5) made of a magnetic material wherein an axial hole is formed between a pole piece part (P) at one end to hold a magnet and a counterweight (4) of a magnetic material at the other end thereof, a non-magnetic material layer (6) molded in a disk shape so as to cover said insert core, and a ratchet claw (7) attached to said insert core and arranged to be given a rotating force by being caught by an engagement part (30) of a rotating reel (16) by operation of a starter rope (17), characterized by an axial part (8) supporting said ratchet claw in freely rotatable manner, a male screw (10) inserted in a perforation formed in both said axial part and said insert core, a nut (11) which fixes said ratchet claw onto said insert core by said male screw which is screwed thereinto through said axial part, and a rotation blocking hole (24) formed in either said insert core or said non-magnetic material layer in order to block rotation of said nut. A magneto electric generator rotor as claimed in Claim 1, characterized in that an axial part (8) supporting said ratchet claw (7) in freely rotating manner is formed in a body with said insert core (5).

Inventors: IWATA MASAO, KAWAI NORIO, KITAMURA YOSHIKI, IWATA, MASAO, KAWAI, NORIO, KITAMURA, YOSHIKI
Applicants: OPPAMA KOGYO KK, OPPAMA INDUSTRY CO., LTD.
Application year: 1996
Main classification: H02K21
IPC codes: H02K1, H02K21, H02K15, F02B63, H02K7, F02N3, F02B1