JP4655672B2 - Flywheel magnet rotor and manufacturing method thereof - Google Patents

Description

  The present invention relates to a flywheel magnet rotor used as a rotor of a magnetic AC generator and a method for manufacturing the same.

  As a generator attached to the internal combustion engine, a magnet type AC generator as shown in FIGS. 11 and 12 is used. 11 and 12, reference numeral 10 'denotes a flywheel magnet rotor, which is an iron cup-shaped flywheel having a peripheral wall portion 11a and a bottom wall portion 11b that closes one end side in the axial direction of the peripheral wall portion. 11 and a permanent magnet 12 attached to the inner periphery of the peripheral wall of the flywheel. A boss portion 11c is provided at the center of the bottom wall portion of the flywheel 11, and a crankshaft of an internal combustion engine (not shown) is fitted into a tapered hole 11d provided in the axial center portion of the boss portion. A stator (not shown) fixed to an engine case, a cover, or the like is disposed inside the rotor 10 ', and the stator and the rotor 10' constitute a magnet type AC generator. A stator (not shown) includes an armature core having a magnetic pole portion facing the magnetic pole of the rotor 10 'and an armature coil wound around the armature core.

  In general, an internal combustion engine requires engine speed information and crank angle information (information on the rotation angle position of the crankshaft) in order to control the ignition timing, fuel injection time, and the like. As a means for obtaining engine rotation speed information and crank angle information, a pulse generator that generates a pulse signal in accordance with rotation of the crankshaft of the engine is used. Various types of pulse generators are known, but when a magnet generator equipped with a flywheel magnet rotor is attached to an engine, a reluctator (induction) provided on the outer periphery of an iron flywheel is used. In many cases, a pulse signal is generated by detecting the edge of a child.

  This type of pulse generator includes an iron core having a magnetic pole portion facing the reluctor at the tip, a signal coil wound around the iron core, and a permanent magnet magnetically coupled to the iron core. When starting to face the magnetic pole part (when detecting the front end edge in the rotation direction of the reluctator) and when the reluctator finishes facing the magnetic pole part of the iron core (detecting the rear end edge in the rotation direction of the relaxor) In this case, a pulse signal is induced in the signal coil by a change in magnetic flux generated in the iron core.

  In the example shown in FIG.11 and FIG.12, the annular protrusion 13 extended over the full length of the circumferential direction of this flywheel is formed in the outer periphery of the surrounding wall part 11a of the flywheel 11, This protrusion 13 Are formed at a distance in the circumferential direction of the flywheel, and the protrusions formed on both sides of the recesses 14, 14,... 15, 15, ..., 15.

  The ridge 13 is formed by turning the outer periphery of the flywheel. In addition, the recess forming recesses 14, 14,... Are formed by using the portions where the respective recess forming recesses are formed near the outer periphery of the protrusion 13 as shown in FIG. It is formed by cutting with a cutting tool (end mill) 16 that moves in the axial direction of the flywheel.

A magnet type AC generator provided with a flywheel magnet rotor as shown in FIGS. 11 and 12 is disclosed in, for example, Patent Document 1.
JP-A-11-355989

  In the flywheel magnet rotor as described above, when the projecting portion 13 is cut by the cutting tool 16 to form the recess forming recess 14, the burr 17 (see FIG. 13) is formed on the peripheral portion of the recess 14 on the side from which the tool comes out. See). Since this burr is formed in a state protruding from the side surface of the ridge portion 13, if left as it is, the operator flies by hand in a later process (a process of attaching a permanent magnet or an assembly process of a magnet generator). There is a risk of injury when touching the ridges of the wheel. For this reason, in the conventional flywheel magnet rotor, it is necessary to perform polishing for removing the burr 17 after forming the reluctator, which increases the number of manufacturing steps of the flywheel magnet rotor and the manufacturing cost. There was a problem of becoming.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a flywheel magnet rotor that eliminates the risk of injury to an operator who assembles a magnetic AC generator due to burrs generated when a signal generating reluctator is formed by cutting, and a method of manufacturing the same. Is to provide.

  The present invention includes a cup-shaped flywheel having a ridge portion provided around the outer periphery of the peripheral wall portion, and a permanent magnet fixed to the inner periphery of the peripheral wall portion of the flywheel, and cuts the ridge portion. Flywheel magnets in which a plurality of recesses for forming a relaxor are formed at intervals in the circumferential direction of the flywheel, and the protrusions formed on both sides of each recess for forming a relaxor are used as signal generating retractors Intended for rotors.

In the present invention, a groove portion extending over the entire circumference of the flywheel is formed on the side surface of the outer ridge portion of the peripheral wall portion of the flywheel, and the recess for forming the relaxor is positioned at the bottom corresponding to the deepest portion of the groove portion. Alternatively , it is provided in a state where it is located at a position corresponding to the vicinity of the deepest part of the groove part, so that burrs generated when cutting the recesses for forming the relaxor are accommodated in the groove part.

  When configured as described above, the burr generated when the recess for forming the reluctator is cut is arranged in the groove, so that the burr can be prevented from touching the operator's hand, and the work for removing the burr is not performed. However, it is possible to eliminate the risk that the operator engaged in assembling the flywheel magnet rotor and the magnet generator will be injured by the burr. Therefore, the polishing step for removing burrs can be omitted, and the manufacturing cost of the flywheel magnet rotor can be reduced and the manufacturing cost can be reduced.

  The present invention also provides a cup-shaped flywheel in which a signal generating reluctator including a plurality of protrusions arranged at intervals in the circumferential direction is formed on the outer periphery of the peripheral wall, and is fixed to the inner periphery of the peripheral wall of the flywheel. The manufacturing method of the flywheel magnet rotor provided with the made permanent magnet is made into object.

In the manufacturing method according to the present invention, a ridge portion forming step for forming a ridge portion extending over the entire circumference of the peripheral wall portion on the outer periphery of the peripheral wall portion of the flywheel, and extending over the entire periphery of the flywheel. A groove portion forming step for forming the groove portion on at least one side surface of the ridge portion, and a plurality of workpieces arranged at predetermined intervals in the circumferential direction of the flywheel are set as the ridge portion, By cutting each workpiece with a cutting tool that moves in the axial direction of the flywheel, a plurality of recesses for forming a reluctator are formed in the ridge , and each bottom is located at a position corresponding to the deepest part of the groove or the deepest part of the groove. formed in a state of being positioned at a position corresponding to the vicinity of parts, the projections formed on both sides of each reluctor forming recess perform a reluctor forming step of the reluctor. In addition, the moving direction of the cutting tool is set so that burrs generated when the respective recesses for forming the relaxors are cut are accommodated in the grooves.

  The ridge portion forming step can be easily performed by performing turning (turning) on the outer periphery of the peripheral wall portion of the flywheel. Further, the groove forming step can be easily performed by turning the side surface of the projecting portion before cutting the recess for forming the relaxor.

  In the relaxor forming step, the moving direction of the cutting tool is set so that the cutting tool is detached from the ridge on the side surface side of the ridge where the groove exists.

  As described above, according to the present invention, a groove is formed on the side surface of the protrusion on the outer periphery of the peripheral wall portion of the flywheel, and the burr generated when the recess for forming the relaxor is cut is accommodated in the groove. As a result, it is possible to prevent the burr from touching the operator's hand, and the worker who is engaged in the assembly of the flywheel magnet rotor and the magnet generator without performing polishing to remove the burr. Can eliminate the risk of injury from burr. Therefore, the polishing step for removing burrs can be omitted, and the manufacturing cost of the flywheel magnet rotor can be reduced and the manufacturing cost can be reduced.

Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 9, the flywheel magnet rotor 10 manufactured in the embodiment of the present invention includes an iron cup having a peripheral wall portion 11 a and a bottom wall portion 11 b that closes one end side in the axial direction of the peripheral wall portion. And a permanent magnet 12 attached to the inner periphery of the peripheral wall portion of the flywheel. A boss portion 11c is provided at the center of the bottom wall portion of the flywheel 11, and a crankshaft of an internal combustion engine (not shown) is fitted into a tapered hole 11d provided in the axial center portion of the boss portion. On the outer periphery of the peripheral wall portion of the flywheel 11, an annular ridge 13 extending over the entire length in the circumferential direction of the flywheel is formed. By cutting the ridge 13, A large number of recesses 14 for forming the relaxor are formed on both the radial side and the axial direction. .. Are formed so as to be arranged at a predetermined interval in the circumferential direction of the flywheel, and the protrusions formed on both sides of the recesses 14 for forming the relaxor are formed. Reluctors 15, 15,... The basic configuration of these magnet rotors is the same as the conventional one.

In this embodiment, as shown in FIGS. 6 and 7, a groove 20 is formed on the side surface of the protrusion 13 on the outer periphery of the peripheral wall 11 a of the flywheel, and the protrusion 13 is connected to the flywheel. A burr 17 ( FIG. 7B ) generated when the recess 14 for forming the reluctor is formed by cutting with a cutting tool (end mill) 16 moving in the axial direction is accommodated in the groove 20.

  More specifically, in the present embodiment, as shown in FIG. 1 and FIG. 2, first, a fly having integrally a peripheral wall portion 11a, a bottom wall portion 11b, and a boss portion 11c is formed by drawing iron. Wheel 11 is manufactured. Next, a step portion 11f for positioning the magnet 12 in the axial direction of the flywheel is formed by cutting the inner periphery of the peripheral wall portion 11a. A mounting hole 11e is formed in the bottom wall portion 11b of the flywheel for mounting a component part of an internal combustion engine starting device, for example, a component part of a recoil starter.

  In the manufacturing method of the present invention, after the cup-shaped flywheel 11 having the peripheral wall portion 11a and the bottom wall portion 11b is formed, the peripheral wall portion 11a of the flywheel is cut by a lathe so that the outer periphery of the flywheel 11 is formed. The ridge part formation process which forms the cyclic | annular ridge part extended over the full length of the circumferential direction of this flywheel is performed. 3 and 4 show a state in which the annular ridge 13 is formed by this ridge formation process.

  Next, as shown in FIGS. 5 and 6, a groove portion forming step is performed in which groove portions 20 are formed on both side surfaces of the ridge portion 13 so as to extend over the entire length in the circumferential direction of the flywheel. This groove portion forming step is performed by cutting the side surface of the ridge portion 13 with a lathe.

  Thereafter, a plurality of recesses 14 for forming a relaxor arranged at predetermined intervals in the circumferential direction of the flywheel are formed in a portion near the outer periphery of the ridge 13, and as shown in FIG. A process of forming a relaxor is performed in which the protrusions formed on both sides of the recesses 14, 14,. In this relaxation forming step, a portion of the ridge portion 13 where the recess for forming the relaxor is formed is set as a processed portion, and cutting that moves in the axial direction of the flywheel as shown in FIG. By cutting each workpiece with a tool (end mill) 16, as shown in FIG. 7 (B), the recess forming recesses 14 opened on the outer diameter side and both sides in the axial direction of the flywheel are formed.

  In the relaxor forming step, as shown in FIG. 7B, the moving direction of the cutting tool 16 and the relaxor are set so that the burrs 17 generated when the respective recesses 14 for forming the relaxor are cut are accommodated in the grooves 20. The depth of the forming recess 14 is set. Preferably, as shown in FIG. 7B, the bottom portion 14a of the recess 14 for forming the relaxor is located at a position corresponding to the deepest portion (the deepest portion) 20a (see FIG. 7B) of the groove portion 20 or near the deepest portion of the groove portion 20. The depth of the recess 14 for forming the relaxor is set so as to be positioned at a position corresponding to the above.

  In order to accommodate the burr 17 generated when the recess 14 for forming the relaxor is cut into the groove 20, the cutting tool 16 is protruded on the side surface of the ridge 13 where the groove 20 is present in the relaxor forming step. What is necessary is just to set the moving direction of the cutting tool 16 so that it may detach | leave from the strip part 13. FIG. When the groove portion 20 is formed on both side surfaces of the ridge portion 13 as in this embodiment, the moving direction of the cutting tool is the direction from the opening side of the flywheel toward the bottom wall portion 11b and the bottom of the flywheel. Any of the direction from the wall part 11b side to the opening part side of this flywheel may be sufficient.

  In the state where the recess forming recess 14 is formed in the protrusion 13 as described above, the groove 20 is divided by the recess forming recess 14, but the position of the bottom 14 a of the recess forming recess 14 is the deepest of the groove 20. If it is set so as to be located at a position corresponding to the groove or a position corresponding to the vicinity of the deepest part of the groove 20, the burr 17 does not protrude from the groove 20.

  .. Are formed on the outer periphery of the peripheral wall portion 11a of the flywheel 11 as described above, and then permanent magnets 12, 12,... Are formed on the inner periphery of the peripheral wall portion of the flywheel 11 as shown in FIG. It arrange | positions, each permanent magnet is contact | abutted to the step part 11f of the inner periphery of a flywheel, and each permanent magnet 12 is positioned in the axial direction of a flywheel. In this state, the permanent magnets are fixed to the flywheel 11 by bonding to complete the flywheel magnet rotor 10.

  When a permanent magnet 12 such as a ferrite magnet is used, a cover for protecting the magnet 12 may be attached to the inner peripheral side of the permanent magnets 12, 12,.

  In the flywheel magnet rotor manufactured as described above, as shown in FIG. 7B, burrs 17 generated when the recess 14 for forming the reluctor is cut are formed on the side surfaces of the ridge 13. Is accommodated in the groove 20. Therefore, even if the operator touches the outer peripheral portion of the flywheel when assembling the generator, the burr does not touch the hand, so that the risk of the burr damaging the operator can be eliminated.

  In the above embodiment, the groove portions 20 are formed on both side surfaces of the ridge portion 13 formed on the outer periphery of the peripheral wall portion of the flywheel. However, when the ridge portion 13 is cut to form the retractor-forming recess portion 14. Since the burr 17 is generated only on the side where the cutting tool 16 is detached from the ridge 13, as shown in FIG. 10, the flywheel is formed only on the side surface of the ridge 13 on the side where the cutting tool 16 is detached. You may make it form the groove part 20 extended over the whole circumferential direction.

  In the above embodiment, four arc-shaped permanent magnets 12 are attached to the peripheral wall portion of the flywheel on the inner periphery with a predetermined angular interval to form a magnet field. A ring-shaped permanent magnet is configured by attaching a plurality of permanent magnets to the inner periphery of the peripheral wall portion without any interval, or an integral ring-shaped permanent magnet is attached to the inner periphery of the flywheel. The permanent magnet may be magnetized so that a predetermined number of magnetic poles are arranged in the circumferential direction to constitute a magnet field.

It is the front view which showed the state before the protrusion part of the flywheel used in embodiment of this invention was formed. It is the II-II sectional view taken on the line of FIG. It is the front view which showed the state which formed the protrusion part in the outer periphery of the surrounding wall part of the flywheel shown in FIG. It is the IV-IV sectional view taken on the line of FIG. It is the front view which showed the state which formed the groove part in the side surface of the protrusion part of the flywheel shown in FIG. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. (A) enlarges a protrusion part and a part of peripheral wall part of a flywheel in order to demonstrate the method of cutting the protrusion part of the outer periphery of a flywheel, and forming a reluctator in other embodiment of this invention. Sectional drawing shown with a cutting tool, (B) is sectional drawing of the protrusion part in which the recessed part for relaxor formation was formed. It is the front view of the principal part which showed the state which formed the reluctator in the protrusion part of the outer periphery of a flywheel in this embodiment. It is a front view of the flywheel magnet rotor of this embodiment. In another embodiment of the present invention, in order to explain a method of cutting a protrusion on the outer periphery of a flywheel to form a reluctator, the protrusion and a part of the peripheral wall of the flywheel are enlarged, and a cutting tool It is sectional drawing shown with. It is the front view which showed the conventional flywheel magnet rotor. It is the XII-XII sectional view taken on the line of FIG. In order to explain the conventional method of cutting the protrusion on the outer periphery of the flywheel to form the reluctator, the protrusion and the part of the peripheral wall of the flywheel are enlarged and shown in a sectional view together with the cutting tool. is there.

DESCRIPTION OF SYMBOLS 10 Flywheel magnet rotor 11 Flywheel 11a Peripheral wall part of flywheel 11b Bottom wall part of flywheel 12 Permanent magnet 13 Projection part 14 Retractor formation recessed part 15 Retractor 16 Cutting tool 17 Burr 20 Groove part

Claims (3)

Ridges on the outer periphery of the peripheral wall portion (11a) (13) and is circumferentially provided cup-shaped flywheel (11), the peripheral wall portion of the flywheel (11a) inner fixed permanent magnet in the peripheral (12) And a plurality of recesses (14) for forming a relaxor formed by cutting the protrusion (13) at intervals in the circumferential direction of the flywheel. In the flywheel magnet rotor in which the protrusions formed on both sides are signal generating reluctators (15) ,
A groove (20) extending over the entire circumference of the flywheel is formed on the side surface of the outer ridge (13) of the outer peripheral wall (11a) of the flywheel (11) ,
The relaxor-forming recess (14) has a bottom (14a) positioned at a position corresponding to the deepest part (20a) of the groove (20) or a position corresponding to the vicinity of the deepest part (20a) of the groove (20). Provided in the state,
A flywheel magnet rotor in which burrs generated when the recess for forming the relaxor is cut are accommodated in the groove (20) . A cup-shaped flywheel (11) having a signal generating reluctator (15) formed of a plurality of protrusions arranged at intervals in the circumferential direction on the outer periphery of the peripheral wall portion (11a) , and a peripheral wall portion of the flywheel. In a method of manufacturing a flywheel magnet rotor comprising a permanent magnet (12) fixed to the inner periphery,
On the outer periphery of the peripheral wall portion of the flywheel (11) , a ridge portion forming step for forming a ridge portion (13) extending over the entire circumference of the peripheral wall portion;
A groove forming step for forming a groove (20) extending over the entire circumference of the flywheel (11) on at least one side surface of the ridge (13) ;
A plurality of workpieces arranged at predetermined intervals in the circumferential direction of the flywheel are set as the ridges (13) , and the workpieces of the ridges are set in the axial direction of the flywheel. By cutting with a moving cutting tool, the protrusion (13) has a plurality of recesses (14) for forming a reluctator , and each bottom (14a) corresponds to the deepest part (20a) of the groove or A relaxor forming step in which the protrusions formed on both sides of each recess forming recesses are formed in a state corresponding to the vicinity of the deepest part (20a) of the groove part (20), and the protrusions formed on both sides of each of the recesses for forming the relaxor,
With
The manufacturing method of the flywheel magnet rotor by which the moving direction of the said cutting tool is set so that the burr | flash produced when each recessed part (14) for reluctator formation is cut may be accommodated in the said groove part (20) .   3. The flywheel magnet rotation according to claim 2, wherein in the relaxor forming step, the moving direction of the cutting tool is set so that the cutting tool is separated from the protruding portion on the side surface side of the protruding portion where the groove portion is present. Child manufacturing method.

Images