JP4772811B2 - Starting motor - Google Patents

Description

  The present invention relates to a starter motor attached to an engine such as an automobile, and more particularly to a shaft cover member mounted on an end of an idle shaft that supports an idle gear meshing with an engine ring gear.

  In an engine used for an automobile, a motorcycle, a large generator, or the like, a starting operation is generally performed by a starting motor (starter motor) attached to the engine. As such a starter motor, a motor provided with an idle gear that is movable in the axial direction is known as disclosed in Patent Document 1. The idle gear is arranged so as to be able to mesh with and disengage from the engine ring gear. Both gears mesh with each other when the engine is started, and the meshing is released after the engine is started. The idle gear also meshes with a pinion that is rotationally driven by the starter motor, and the pinion is connected to the rotation shaft of the motor via an overrunning clutch.

  FIG. 11 is an explanatory diagram showing the configuration of such a conventional starting motor. The starting motor 201 is roughly composed of a motor unit 202, a gear unit 203, a magnet switch unit 204, a case unit 205, and an idle unit 206. The motor unit 202 is provided with a motor 211 that is a drive source. Further, the gear unit 203 is provided with a planetary gear mechanism 212, an overrunning clutch 213, a pinion gear 214, and the like that are reduction gears. Further, an idle gear 215 that meshes with the pinion gear 214 is disposed in the idle portion 206.

  FIG. 12 is a perspective view showing a configuration of the idle unit 206. The idle gear 215 is attached to the idle shaft 216 so as to be rotatable and movable in the axial direction (vertical direction in FIG. 12 and horizontal direction in FIG. 11). When the idle gear 215 moves upward in FIG. 12, it meshes with the ring gear 217 of the engine. As shown in FIG. 12, the idle shaft 216 is supported by bearing portions 221 and 222 formed on the gear cover 219, and is fixed to the gear cover 219 by a fixing screw 223. A rubber shaft cover 224 is attached to the upper end portion of the idle shaft 216. The shaft cover 224 includes a disc portion 225 and a semi-cylindrical portion 226 and is attached to a recess 227 formed in the gear cover 219.

In the starting motor 201, when the motor 211 rotates, the rotation is transmitted to the pinion gear 214 via the planetary gear mechanism 212 and the overrunning clutch 213. At that time, the pinion gear 214 moves to the left in the drawing by the action of the helical spline portion 218, and the idle gear 215 moves to the left while rotating together with the pinion gear 214. Thereby, the idle gear 215 meshes with the ring gear 217, the rotational force of the motor 211 is transmitted to the ring gear 217 via the idle gear 215, and the engine is started.
WO2007 / 034666A1 Publication

  However, in such a starter motor 201, the shaft cover 224 does not have a shape that takes into consideration the assembling property and the sealing property, and it is difficult to determine the position of the cover during assembling work, and the sealing property is sufficient even after assembling. There was a problem that could not be said. That is, first, regarding the assembling property, since the semi-cylindrical portion 226 is easy to rotate in the concave portion 227 having a semicircular cross section, the position of the cover in the circumferential direction is unambiguously attached to the concave portion 227. There was a problem that it was not decided. Therefore, the shaft cover 224 may be attached to the gear cover 219 in a state where the flat surface portion 228 of the semi-cylindrical portion 226 and the end surface 229 of the gear cover 219 are not flush with each other.

  Here, when attaching the starter motor 201 to the engine, a gasket is attached between the starter motor 201 and the engine so as to be in close contact with the flat portion 228. However, as described above, when the shaft cover 224 is not flush with the end surface 229 and the semi-cylindrical portion 226 protrudes from the end surface 229, a gap is formed between the gasket and the shaft cover 224. There is a possibility. For this reason, it is necessary to carefully perform the assembling work so that the semi-cylindrical portion 226 does not jump out of the end surface 229, and there is a problem that the assembling workability is impaired and the number of work steps is increased.

  Next, regarding the sealing performance of the shaft cover 224, there were the following problems. That is, in the starting motor 201, when the shaft cover 224 is attached to the recess 227, the outer end portion of the recess 227 is open to the outside, and there is a risk that moisture, dust, etc. may enter the recess 227 from there. There was a problem that there was. In this case, a rubber shaft cover 224 is fitted in the recess 227, and in a state where the starting motor 201 is attached to the engine, a pressing force is applied in the radial direction, and a certain degree of sealing performance is secured. However, as long as the end of the recess 227 is opened, it is inevitable that moisture penetrates into the recess 227 from the outside (from the direction of arrow X in FIG. 12) or dust enters. I couldn't say that it was enough in terms of defense.

  The object of the present invention is to improve the assembling and sealing properties of the shaft cover used in the starting motor, to enable easy and reliable positioning when the shaft cover is mounted, and to provide waterproof and dustproof properties for the cover portion. Is to improve.

  A starter motor of the present invention is driven by an electric motor and driven in an axial direction so as to mesh with an engine ring gear by moving in an axial direction, an idle shaft that supports the idle gear rotatably and movable in an axial direction, A cover member that is attached to the engine and includes a shaft hole through which the idle shaft is inserted, and a concave portion that is formed facing the shaft hole, and a shaft cover that is attached to the concave portion and covers one end side of the idle shaft The shaft cover includes: a disk part mounted in the shaft hole; a semi-cylindrical part having a substantially semicircular cross section formed integrally with the disk part and extending in the axial direction; A fitting attachment portion having a polygonal cross section formed integrally with the semicylindrical portion at an end of the semicylindrical portion, and the recess is formed in a substantially semicircular cross section. And having a semi-circular cross section cylindrical portion is mounted, and a corner section portion for mating with the mating mount portion is formed in a polygonal section.

  In the present invention, the fitting attachment portion of the shaft cover and the angular cross-section portion of the cover member are fitted in a predetermined positional relationship. Accordingly, the mounting position of the shaft cover, in particular, the mounting position in the rotational direction is defined without blurring. For this reason, the shaft cover can be positioned easily and reliably during the shaft cover assembling work, and the shaft cover can be prevented from jumping out from the end face of the cover member.

  In the starter motor, the fitting attachment portion may be added to the outer periphery of the semi-cylindrical portion. Moreover, it is good also as a structure which extends the said fitting attachment part in the axial direction from the edge part of the said semi-cylindrical part.

  Another starting motor of the present invention includes an idle gear that is rotationally driven by the motor and moves in the axial direction to mesh with the ring gear of the engine, and an idle shaft that supports the idle gear so as to be rotatable and movable in the axial direction. A cover member that is attached to the engine and includes a shaft hole through which the idle shaft is inserted, and a recess formed to face the shaft hole, and is attached to the recess and covers one end side of the idle shaft A starter motor having a shaft cover, wherein the shaft cover is formed integrally with the disc portion in an axial direction in a state of being eccentric with the disc portion attached to the shaft hole. It has a semi-cylindrical portion extending in a semi-elliptical section, and the concave portion is formed in a semi-elliptical cross-section fitting with the semi-cylindrical portion.

  In the present invention, the semi-cylindrical portion of the shaft cover and the concave portion of the cover member, both of which have a semi-elliptical cross section, are fitted in a predetermined positional relationship. Accordingly, the mounting position of the shaft cover, in particular, the mounting position in the rotational direction is defined without blurring. For this reason, the shaft cover can be positioned easily and reliably during the shaft cover assembling work, and the shaft cover can be prevented from jumping out from the end face of the cover member.

Still another starting motor of the present invention includes an idle gear that is rotationally driven by the electric motor and meshes with an engine ring gear by moving in the axial direction, and an idle shaft that supports the idle gear so as to be rotatable and movable in the axial direction. And a cover member that is attached to the engine and has a shaft hole through which the idle shaft is inserted, and a recess formed facing the shaft hole, and is attached to the recess and covers one end side of the idle shaft The shaft cover includes: a disc portion mounted in the shaft hole; and a semicircular cylinder having a substantially semicircular cross section formed integrally with the disc portion and extending in the axial direction. And a fitting piece formed on the outer peripheral end of the semi-cylindrical portion and extending in the radial direction,
The concave portion has a semicircular cross-sectional portion that is formed in a substantially semicircular cross section and is fitted with the semicylindrical portion, and a fitting groove that fits the fitting piece.

  In the present invention, the fitting piece of the shaft cover and the fitting groove of the cover member are fitted in a predetermined positional relationship. Accordingly, the mounting position of the shaft cover, in particular, the mounting position in the rotational direction is defined without blurring. For this reason, the shaft cover can be positioned easily and reliably during the shaft cover assembling work, and the shaft cover can be prevented from jumping out from the end face of the cover member.

  The starter motor may further include a bellows portion provided with a plurality of irregularities along the axial direction on an outer periphery of the semi-cylindrical portion of the shaft cover. As a result, when the starter motor is attached to the engine, the shaft cover is pushed in the radial direction from the engine side, whereby the convex portion vertex of the bellows portion is pressed against the concave portion, and the sealing performance of the shaft cover portion is improved.

  According to the starter motor of the present invention, the shaft cover that covers one end side of the idle shaft is provided with a disk portion, a semi-cylindrical portion having a substantially semicircular cross section, and a fitting attachment portion having a polygonal cross section. Since the concave portion of the cover member to which the shaft cover is attached is provided with a semicircular cross-sectional portion where the semi-cylindrical portion is attached and a square cross-sectional portion which is formed in a polygonal cross-section and engages with the fitting mounting portion, the shaft cover The fitting mounting portion and the angular cross-section portion of the cover member are fitted in a predetermined positional relationship, and the shaft cover can be easily and reliably positioned during the shaft cover assembling operation. For this reason, the assembly workability is improved, the number of work steps can be reduced, and the cost of the product can be reduced. Also, the shaft cover can be prevented from jumping out from the end face of the cover member, and when the starter motor is attached to the engine, a gap may be created between the gasket and the shaft cover due to the shaft cover jumping out. Can be prevented.

  According to another starter motor of the present invention, the shaft cover that covers one end side of the idle shaft is provided with a disc portion and a semi-cylindrical half-cylindrical portion that is eccentric to the disc portion, and the shaft cover Since the concave portion of the cover member to be mounted is formed in a semi-elliptical cross section that fits with the semi-cylindrical portion, the semi-cylindrical portion of the shaft cover and the concave portion of the cover member are fitted in a predetermined positional relationship, and the shaft cover is assembled. It becomes possible to easily and reliably position the shaft cover at the time. For this reason, the assembly workability is improved, the number of work steps can be reduced, and the cost of the product can be reduced. Also, the shaft cover can be prevented from jumping out from the end face of the cover member, and when the starter motor is attached to the engine, a gap may be created between the gasket and the shaft cover due to the shaft cover jumping out. Can be prevented.

  According to still another starter motor of the present invention, the shaft cover that covers one end side of the idle shaft is formed on the disc portion, the semi-cylindrical portion having a substantially semicircular cross section, and the outer peripheral end portion of the semi-cylindrical portion. A fitting piece extending in the radial direction is provided, and a semicircular cross-sectional portion to which the semi-cylindrical portion is attached and a fitting groove to be fitted to the fitting piece are provided in the concave portion of the cover member to which the shaft cover is attached. Therefore, the fitting piece of the shaft cover and the fitting groove of the cover member are fitted in a predetermined positional relationship, and the shaft cover can be easily and reliably positioned during the shaft cover assembling operation. For this reason, the assembly workability is improved, the number of work steps can be reduced, and the cost of the product can be reduced. Also, the shaft cover can be prevented from jumping out from the end face of the cover member, and when the starter motor is attached to the engine, a gap may be created between the gasket and the shaft cover due to the shaft cover jumping out. Can be prevented.

  Further, according to the starter motor of the present invention, by providing the bellows portion on the outer periphery of the semi-cylindrical portion of the shaft cover, when the starter motor is attached to the engine, the convex vertex of the bellows portion is pressed against the inner periphery of the recess. It becomes possible to improve the sealing performance of the shaft cover portion.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing a configuration of a starter motor that is Embodiment 1 of the present invention. A starter motor (starter) 1 shown in FIG. 1 is used for starting an automobile engine, and gives the engine that is stopped to rotate necessary for fuel intake, atomization, compression, and ignition.

  The starter motor 1 is roughly composed of a motor unit 2, a gear unit 3, a magnet switch unit 4, a case unit 5 and an idle unit 6. A motor (electric motor) 11 as a drive source is disposed in the motor unit 2, and a planetary gear mechanism 12, an overrunning clutch 13, a pinion gear 14, and the like as a reduction device are disposed in the gear unit 3. An idle gear 15 that meshes with the pinion gear 14 is disposed in the idle portion 6. The idle gear 15 is attached so as to be movable in the axial direction (left-right direction in the figure), and when moved in the left direction in the figure (hereinafter, the left-right direction is omitted from the description in the figure with reference to FIG. 1). Meshes with the ring gear 16 of the engine. The rotational force of the motor 11 is transmitted to the pinion gear 14 via the planetary gear mechanism 12 and the overrunning clutch 13, and is transmitted from the idle gear 15 to the ring gear 16 to start the engine.

  The motor 11 has a configuration in which an armature 22 is rotatably disposed in a cylindrical motor housing 21. The motor housing 21 also serves as the yoke of the motor 11 and is made of a magnetic metal such as iron. A metal end cover 23 is attached to the right end portion of the motor housing 21. On the other hand, the left end portion of the motor housing 21 is attached to the gear cover 24 of the case portion 5. The end cover 23 is fixed to the gear cover 24 by a set bolt 25, and the motor housing 21 is fixed between the end cover 23 and the gear cover 24.

  A plurality of permanent magnets 26 are fixed in the circumferential direction on the inner peripheral surface of the motor housing 21, and the armature 22 is disposed inside the permanent magnet 26. The armature 22 includes an armature core 28 fixed to the motor shaft 27 and an armature coil 29 wound around the armature core 28. The right end portion of the motor shaft 27 is rotatably supported by a metal bearing 31 attached to the end cover 23. On the other hand, the left end portion of the motor shaft 27 is rotatably supported by an end portion of a drive shaft (output shaft) 32 to which the pinion gear 14 and the like are attached. A bearing 33 is recessed at the right end of the pinion shaft 32, and the motor shaft 27 is rotatably supported by a metal bearing 34 attached thereto.

  A commutator 35 that is externally fitted and fixed to the motor shaft 27 is disposed adjacent to one end of the armature core 28. A plurality of commutator pieces 36 formed of a conductive material are attached to the outer peripheral surface of the commutator 35, and the end of the armature coil 29 is fixed to each commutator piece 36. A brush holder 37 is attached to the left end portion of the motor housing 21. In the brush holder 37, four brush accommodating portions 38 are arranged at intervals in the circumferential direction. Each brush accommodating portion 38 is internally provided with a brush 39 that can be moved in and out. The protruding tip end portion (inner diameter side tip portion) of the brush 39 is in sliding contact with the outer peripheral surface of the commutator 35.

  A pigtail (not shown) is attached to the rear end side of the brush 39 and is electrically connected to the conductive plate 41 of the brush holder 37. The conductive plate 41 is provided with a switch portion 42, and when the switch plate 43 contacts the conductive plate 41, the power terminal 44 and the brush 39 are electrically connected, and power is supplied to the commutator 35. The switch plate 43 is attached to the switch shaft 45, and when the magnet switch unit 4 is energized, the switch shaft 45 moves to the left and the switch plate 43 comes into contact with the conductive plate 41.

  The planetary gear mechanism 12 of the gear unit 3 is provided with an internal gear unit 46 and a drive plate unit 47. The internal gear unit 46 is fixed to the right end portion of the gear cover 24, and an internal gear 48 is formed on the inner peripheral side thereof. A metal bearing 49 is housed in the center of the internal gear unit 46, and the right end side of the pinion shaft 32 is rotatably supported. The drive plate unit 47 is fixed to the right end of the pinion shaft 32, and the planetary gears 51 are attached at equal intervals. The planetary gear 51 is rotatably supported by a support pin 53 fixed to the base plate 52 via a metal bearing 54. The planetary gear 51 is in mesh with the internal gear 48.

  A sun gear 55 is formed at the left end of the motor shaft 27. The sun gear 55 meshes with the planetary gear 51, and the planetary gear 51 revolves between the sun gear 55 and the internal gear 48 while rotating. When the motor 11 is operated, the sun gear 55 rotates with the motor shaft 27, and the planetary gear 51 revolves around the sun gear 55 while meshing with the internal gear 48 as the sun gear 55 rotates. As a result, the base plate 52 fixed to the pinion shaft 32 rotates, and the rotation of the motor shaft 27 is decelerated and transmitted to the pinion shaft 32.

  The overrunning clutch 13 transmits the rotation decelerated by the planetary gear mechanism 12 to the pinion gear 14 in one rotation direction. The overrunning clutch 13 has a configuration in which a roller 58 and a clutch spring 59 are arranged between the clutch outer 56 and the clutch inner 57. The clutch outer 56 includes a boss portion 56 a and a clutch portion 56 b, and the boss portion 56 a is attached to the helical spline portion 61 of the pinion shaft 32. A spline portion 62 that meshes with the helical spline portion 61 is formed on the inner peripheral side of the boss portion 56a. As a result, the clutch outer 56 can move in the axial direction along the helical spline portion 61 on the pinion shaft 32.

  A stopper 63 is attached to the pinion shaft 32. The stopper 63 is restricted from moving in the axial direction by a circlip 64 attached to the pinion shaft 32. One end of a gear return spring 65 is attached to the stopper 63. The other end side of the gear return spring 65 is in contact with the inner end wall 66 of the boss portion 56a. The clutch outer 56 is urged to the right by the gear return spring 65, and the clutch outer 56 is held at a position in contact with a clutch stopper 67 fixed to the gear cover 24 during normal operation (when power is not supplied). Is done.

  A clutch inner 57 formed integrally with the pinion gear 14 is disposed on the inner periphery of the clutch portion 56 b of the clutch outer 56. A plurality of sets of rollers 58 and clutch springs 59 are arranged between the clutch outer 56 and the clutch inner 57. A clutch cover 68 is externally provided on the outer periphery of the clutch portion 56 b, and a clutch washer 69 is attached between the left end surface of the clutch portion 56 b and the clutch cover 68. By this clutch washer 69, the roller 58 and the clutch spring 59 are accommodated on the inner peripheral side of the clutch portion 56b in a state where movement in the axial direction is restricted.

  The inner peripheral wall of the clutch portion 56b is a cam surface, and a wedge-shaped slope portion and a curved surface portion are formed. The roller 58 is normally pushed to the curved surface side by the clutch spring 59. When the clutch outer 56 rotates and the roller 58 is sandwiched between the wedge-shaped slope portion and the outer peripheral surface of the clutch inner 57 against the urging force of the clutch spring 59, the clutch inner 57 is engaged with the clutch via the roller 58. It rotates integrally with the outer 56. Thus, when the motor 11 is operated and the pinion shaft 32 rotates, the rotation is transmitted from the clutch outer 56 to the clutch inner 57 via the roller 58, and the pinion gear 14 rotates.

  On the other hand, when the engine is started and the clutch inner 57 rotates faster than the clutch outer 56, the roller 58 moves to the curved surface side, and the clutch inner 57 is idled with respect to the clutch outer 56. That is, when the clutch inner 57 is in an overrun state, the roller 58 is not sandwiched between the wedge-shaped slope and the outer peripheral surface of the clutch inner, and the rotation of the clutch inner 57 is not transmitted to the clutch outer 56. Therefore, even if the clutch inner 57 is rotated at a higher rotational speed from the engine side after the engine is started, the rotation is interrupted by the overrunning clutch 13 and is not transmitted to the motor 11 side.

  The pinion gear 14 is a steel member formed by cold forging and meshes with the idle gear 15. As the pinion gear 14 and the idle gear 15, chrome steel (for example, SCr 420H) subjected to carburizing treatment is used. The pinion gear 14 is formed integrally with the clutch inner 57, and a gear portion 71 and a boss portion 94 are formed on the left side of the clutch inner 57. The outer diameter of the boss portion 94 is smaller than the outer diameter of the bottom of the gear portion 71, so that the pinion gear 14 can be easily cold forged. Since the pinion gear 14 is formed by cold forging, the accuracy of the axial dimension of the gear portion 71 is high, the backlash between parts such as between the pinion gear 14 and the idle gear 15 is small, and wear and breakage are suppressed. . Further, by forming the gear portion 71 by cold forging, work hardening occurs, the strength of the gear portion 71 increases, and the strength of the gear connecting portion is improved.

  A steel pinion washer 72 is extrapolated to the boss portion 94. The pinion washer 72 is secured to the axial direction by a C-ring 73 attached to the boss portion 94. The outer peripheral portion of the pinion washer 72 is in contact with the left side surface of the idle gear 15. When the starter motor 1 stops after the engine is started, the idle gear 15 is moved to the right together with the pinion gear 14. Release from the ring gear 16. A flange portion 95 is formed on the right side of the gear portion 71.

  A shaft hole 74 and a spring accommodating portion 75 are formed on the inner diameter side of the pinion gear 14. A pinion gear metal 76 is attached to the shaft hole 74, and the pinion gear 14 is rotatably supported by the pinion shaft 32 via the pinion gear metal 76. The spring accommodating portion 75 is formed on the inner peripheral side of the clutch inner 57, and the stopper 63 and the gear return spring 65 are accommodated therein.

  The magnet switch unit 4 is arranged concentrically with the motor 11 and the planetary gear mechanism 12 on the left side of the planetary gear mechanism 12. The magnet switch portion 4 includes a steel fixed portion 77 fixed to the gear cover 24 and a movable portion 78 disposed so as to be movable in the left-right direction along the fixed iron core 82. The fixed portion 77 is provided with a case 79 fixed to the gear cover 24, a coil 81 accommodated in the case 79, and a fixed iron core 82 attached to the inner peripheral side of the case 79. The movable part 78 is provided with a movable iron core 83 to which the switch shaft 45 is attached, and a gear plunger 84 is attached to the inner peripheral side of the movable iron core 83. A switch return spring 90 is attached to the outer peripheral side (lower end in the figure) of the movable iron core 83. The other end side of the switch return spring 90 is in contact with the gear cover 24, and the movable iron core 83 is urged to the right.

  A bracket plate 85 is further fixed to the inner periphery of the movable iron core 83. One end of a plunger spring 86 is caulked and fixed to the bracket plate 85. The other end of the plunger spring 86 is in contact with the gear plunger 84 when the ignition key switch is OFF (in the state shown in FIG. 1), and the gear plunger 84 is urged to the left by the plunger spring 86. Yes. The gear plunger 84 is attached to the pinion shaft 32 so as to be movable in the axial direction, and a sliding iron core 87 is interposed between the inner peripheral surface of the movable iron core 83.

  The case portion 5 includes an aluminum die-cast gear cover 24, and the left end side of the pinion shaft 32 is rotatably supported by the gear cover 24 via a metal bearing 88. An idle shaft 89 that supports the idle gear 15 is also attached to the gear cover 24. The left end side of the idle shaft 89 is secured by an idle shaft stopper (not shown). As described above, the synthetic resin (for example, glass fiber reinforced polyamide) clutch stopper 67 and the case 79 are fixed in the gear cover 24, and the motor housing 21 and the end cover 23 are set bolts on the right end surface side. 25 is fixed.

  An idle gear 15 is disposed in the idle unit 6. An idle gear mounting portion 100 is provided on the gear cover 24, and the idle gear 15 is disposed in a state where the idle gear 15 is pivotally supported by the idle shaft 89. The idle gear 15 is provided with a gear portion 92 and a boss portion 93, and the gear portion 92 meshes with the gear portion 71 of the pinion gear 14. A collar 96 made of synthetic resin (for example, glass fiber reinforced polyamide) is externally mounted on the boss portion 93. The collar 96 is interposed between the end face of the idle gear 15 and the flange portion 95 of the pinion gear 14. Grease is applied as a lubricant between the collar 96 and the flange portion 95 and the idle gear 15 to improve the slidability. A C ring 97 attached to the boss portion 93 is in contact with the right end portion of the collar 96. The collar 96 is fixed and secured in the axial direction by the C ring 97.

  The idle gear 15 is rotatably supported on the idle shaft 89 via a metal bearing 91. The idle shaft 89 is pivotally supported by bearings 98 and 99 provided on the gear cover 24. A shaft hole 101 and a shaft hole 102 are formed in the bearing portions 98 and 99, respectively. The idle shaft 89 is attached between the shaft hole 101 and the shaft hole 102 with the idle gear 15 being pivotally supported. The idle shaft 89 is inserted into the gear cover 24 from the shaft hole 101 side and is inserted into the shaft hole 102. After the idle shaft 89 is inserted to the back of the shaft hole 102, the idle shaft 89 is fixed with a fixing screw 103 as shown in FIG. As a result, the idle shaft 89 is fixed to the gear cover 24 in a state where it is prevented from rotating and prevented from coming off.

  After the idle shaft 89 is screwed, a rubber shaft cover 104 is attached to the end of the idle shaft 89 on the bearing portion 98 side. A recess 105 for attaching the shaft cover 104 is formed in the gear cover 24, and the shaft cover 104 is attached to the shaft hole 101 and the recess 105.

  2 is a perspective view showing the configuration of the shaft cover 104 used in the starting motor 1 according to the first embodiment of the present invention, FIG. 3 is a side view of the shaft cover 104, and FIG. 4 is an attached state of the shaft cover 104. It is explanatory drawing shown. As shown in FIGS. 2 and 3, the shaft cover 104 is also mounted on one end side of the shaft hole 101 like the conventional shaft cover 224, and includes a disc portion 106 and a semi-cylindrical portion 107. The disc portion 106 is formed to have substantially the same diameter as the idle shaft 89, and the shaft cover 104 is attached to the gear cover 24 in such a manner that one end surface of the disc portion 106 contacts the end surface of the idle shaft 89. As with the conventional shaft cover 224, the semi-cylindrical portion 107 is formed integrally with the disc portion 106 on the other end surface side of the disc portion 106 and extends in the axial direction. A portion of the recess 105 on the side of the shaft hole 101 is a semicircular cross section 108, and the semicylindrical portion 107 is mounted in the semicircular cross section 108.

  Here, in the shaft cover 104 according to the present invention, as shown in FIGS. 2 and 3, unlike the conventional shaft cover 224, a fitting attachment portion 109 having a square cross section is added on the end side of the semi-cylindrical portion 107. Yes. The fitting attachment portion 109 is provided in such a manner that the outer peripheral portion of the semi-cylindrical portion 107 is expanded in a quadrangular shape, and is formed with a thickness T that is approximately half the axial direction of the semi-cylindrical portion 107. Therefore, the end surface of the semi-cylindrical portion 107 has a shape in which the quadrangular cross section 110 and the partial circular cross section 111 are combined. On the other hand, a fitting mounting portion 112 is formed in the recess 105 of the gear cover 24 in accordance with the fitting mounting portion 109. The fitting / mounting portion 112 is composed of an angular cross-sectional portion 112a in which a portion of the square cross-sectional portion 110 is fitted, and a circumferential cross-sectional portion 112b in which a portion of the partial circular cross-sectional portion 111 is fitted. The internal dimensions of the angular cross section 112a and the circumferential cross section 112b are substantially the same as the external dimensions of the square cross section 110 and the partial circular cross section 111, respectively.

  On the outer periphery of the semi-cylindrical portion 107, a bellows portion 113 in which a plurality of irregularities are continuously formed along the axial direction is provided. As shown in FIG. 4, the shaft cover 104 has a disc portion 106 inserted into the shaft hole 101, a semi-cylindrical portion 107 in the semicircular cross-sectional portion 108 of the recess 105, and a fitting attachment portion 109 in the fitting mounting portion. It is attached to the gear cover 24 so as to be fitted into the respective 112. At that time, the fitting attachment portion 109 and the square cross-section portion 112a formed in a quadrangular shape are fitted only in a predetermined positional relationship. Therefore, the mounting position of the shaft cover 104, in particular the mounting position in the rotational direction, is uniquely defined without blurring. For this reason, the shaft cover 104 can be easily and reliably positioned at the time of the shaft cover assembling work, and the assembling workability is improved, the work man-hours are reduced, and the product cost is reduced. Is possible.

  On the other hand, when the fitting mounting portion 109 and the fitting mounting portion 112 are fitted, the flat portion 114 of the shaft cover 104 is set to be flush with the end surface 115 of the gear cover 24. Therefore, when the shaft cover 104 is fitted and mounted on the gear cover 24 in the manner described above, the flat surface portion 114 and the end surface 115 are automatically flush with each other. For this reason, when the starter motor 1 is attached to the engine, there is no gap between the gasket and the shaft cover 104 due to the protruding of the shaft cover 104, and the sealing performance of the engine joint portion is improved.

  Further, when the shaft cover 104 is attached to the gear cover 24, the bellows portion 113 is in close contact with the inner peripheral surface 116 of the semicircular cross-sectional portion 108. The outer diameter of the bellows portion 113 is slightly larger than the outer diameter of the disc portion 106, and when the shaft cover 104 is attached to the gear cover 24, the convex portion apex of the bellows portion 113 contacts the inner peripheral surface 116. . In this state, when the starter motor 1 is attached to the engine, the bellows portion 113 is pushed in the radial direction from the engine side via a gasket, and the apex of the convex portion is pushed against the inner peripheral surface 116. As a result, the shaft cover 104 is attached in a sealed state to the gear cover 24, and even if the external opening end of the recess 105 is open to the atmosphere, moisture, dust, etc. enter the shaft hole 101 from there. Can be suppressed. Therefore, as compared with the conventional shaft cover, the sealing performance at the shaft cover portion is enhanced, and the product reliability is improved.

  Note that the flat surface portion 114 of the shaft cover 104 is provided with a protrusion 117 protruding in the radial direction. When the starter motor 1 is attached to the engine, the protrusion 117 is pressed in the radial direction from the opposed surface on the engine side via a gasket. As a result, the bellows portion 113 is more strongly pressed against the inner peripheral surface 116 of the semicircular cross section 108, and the sealing performance is improved. In addition, even if a gap is generated between the gasket and the shaft cover 104, a pressing force can be applied to the shaft cover 104 by the projection 117, so that the shaft cover 104 and the recess 105 (semicircular cross-section portion 108) can be applied. It is possible to ensure a sealing property between the two.

  Note that the fitting attachment portion 109 may be substantially rectangular in a shape in which the partial circular cross-section portion 111 of the shaft cover 104 is deleted. FIG. 5 is a perspective view showing the configuration of such a modification. In the shaft cover 118 of FIG. 5, a fitting attachment portion 109 having a square cross section extends in the axial direction from the end portion of the semi-cylindrical portion 107. The fitting attachment portion 109 has a substantially rectangular shape, and the portion of the partial circular cross-section portion 111 does not protrude like the shaft cover 104 of FIGS. In addition, a fitting mounting portion 112 is formed in the recess 105 on the gear cover 24 side in accordance with the fitting mounting portion 109. The fitting mounting portion 112 is not provided with the circumferential cross-section portion 112b, but is provided with only the angular cross-section portion 112a having a square cross section. Also in such a shaft cover 118, the fitting mounting portion 109 and the fitting mounting portion 112 that are formed in a square shape are fitted only in a predetermined positional relationship, and the mounting position of the shaft cover 118 is not blurred. It is uniquely defined.

  Next, the engine starting operation using such a starting motor 1 will be described. First, when the ignition key switch of the automobile is OFF, the clutch outer 56 is in contact with the clutch stopper 67 by the biasing force of the gear return spring 65 as shown in FIG. At this time, the switch plate 43 is separated from the conductive plate 41 and no power is supplied to the motor 11. Further, the idle gear 15 is in the right disengagement position and is not engaged with the ring gear 16. On the other hand, when the ignition key switch is turned on, the idle gear 15 moves to the left and meshes with the ring gear 16.

  That is, when the ignition key switch is turned on, first, a current flows through the coil 81 and an attractive force is generated in the magnet switch unit 4. When the coil 81 is excited, a magnetic path passing through the case 79 and the fixed iron core 82 is formed, and the movable iron core 83 is attracted to the left. When the movable iron core 83 moves to the left against the urging force of the switch return spring 90, the switch shaft 45 also moves to the left, the switch plate 43 contacts the conductive plate 41, and the contact is closed. As a result, the power terminal 44 and the brush 39 are electrically connected, power is supplied to the commutator 35, the motor 11 is started, and the armature 22 rotates. Further, the bracket plate 85 also moves to the left, and accordingly, the plunger spring 86 is also compressed.

  When the armature 22 rotates, the pinion shaft 32 rotates through the planetary gear mechanism 12. As the pinion shaft 32 rotates, the clutch outer 56 attached to the helical spline portion 61 also rotates. The helical spline portion 61 has a twisting direction set in consideration of the rotational direction of the pinion shaft 32. When the rotational speed of the clutch outer 56 increases, the inertial mass causes the clutch outer 56 to move along the helical spline portion 61. Move to the left (stationary position → operating position). When the clutch outer 56 jumps out to the left, the pinion gear 14 moves to the left together with the clutch outer 56. At this time, the gear return spring 65 is also pressed by the clutch outer 56 and contracted.

  When the clutch outer 56 moves to the left, the idle gear 15 is also pushed by the pinion flange portion 95 to move to the left and meshes with the ring gear 16. When the idle gear 15 meshes with the ring gear 16, the rotation of the motor 11 is transmitted to the ring gear 16, and the ring gear 16 rotates. The ring gear 16 is connected to the crankshaft of the engine. As the ring gear 16 rotates, the crankshaft is rotated and the engine is started. When the engine starts, the pinion gear 14 is rotated at a high speed from the ring gear 16 through the idle gear 15, but the rotation is not transmitted to the motor 11 side due to the action of the overrunning clutch 13.

  When the clutch outer 56 moves to the left, the gear plunger 84 moves to the left by the urging force of the plunger spring 86 that has been compressed, and the gear plunger 84 abuts against the right end surface of the clutch outer 56. At this time, the plunger spring 86 is in a natural length state, and a slight gap is generated between the gear plunger 84 and the plunger spring 86 that are in contact with the clutch outer 56.

  Here, when the engine is started, the pinion gear 14 is rotated at a high speed, and the overrunning clutch 13 is rotated in the idling direction. When the overrunning clutch 13 is rotated in the idling direction, idling torque is generated in the clutch, and a rotational force called cutting torque acts on the clutch outer 56. Due to this rotational force, a thrust force to the right is generated in the clutch outer 56 via the helical spline portion 61, and the clutch outer 56 may move to the right and the idle gear 15 may be detached from the ring gear 16. For this reason, in the starting motor 1, the clutch outer 56 is held at the operating position by the gear plunger 84, and the movement of the idle gear 15 to the right is restricted to prevent the idle gear 15 from being detached.

  On the other hand, when the engine is started and the ignition key switch is turned off, the energization to the magnet switch unit 4 is also stopped and the attractive force disappears. Then, the bracket plate 85 is pushed to the right by the urging force of the switch return spring 90, and the movable iron core 83 that has been held to the left by the suction force by the fixed iron core 82 moves to the right. When the movable iron core 83 moves to the right, the switch shaft 45 also moves to the right, the switch plate 43 is separated from the conductive plate 41, and the contact is opened. Thereby, the power supply to the motor 11 is interrupted, the rotation of the pinion shaft 32 is stopped, and the rotation of the clutch outer 56 is also stopped.

  When the rotation of the clutch outer 56 stops, the moving force in the axial direction due to the inertia mass disappears. For this reason, the clutch outer 56 moves to the right from the operating position to the stationary position along the helical spline portion 61 by the biasing force of the gear return spring 65 that has been compressed. At this time, the gear plunger 84 is also pushed by the clutch outer 56 and returns to the state shown in FIG. The biasing force of the gear return spring 65 is set to be larger than the biasing force of the plunger spring 86 at this time.

  When the clutch outer 56 moves to the right, the pinion gear 14 also moves to the right. When the pinion gear 14 moves to the right, the pinion washer 72 comes into contact with the left end surface of the idle gear 15. As a result, the idle gear 15 is moved to the right by the pinion washer 72, and the idle gear 15 is detached from the ring gear 16 to be in the state shown in FIG.

  Next, a starter motor that is Embodiment 2 of the present invention will be described. 6 is a perspective view showing the configuration of a shaft cover 121 used in a starting motor that is Embodiment 2 of the present invention, FIG. 7 is a plan view of the shaft cover 121 (arrow Y in FIG. 6), and FIG. 8 is a shaft cover. FIG. 12 is an explanatory view showing a state where 121 is attached. The configuration is the same as that of the first embodiment except for the configuration of the shaft cover 121 and its mounting portion. In the following embodiments, the same members and portions as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

  As shown in FIG. 6, the shaft cover 121 is formed of a circular disc part 122 and a semi-cylindrical part 123, and a bellows part 124 is formed on the outer periphery of the semi-cylindrical part 123. In the shaft cover 121 used in the present embodiment, the cross section of the semi-cylindrical portion 123 is substantially semi-elliptical as shown in FIG. The center of the semi-cylindrical portion 123 is arranged at a position different from the center of the disc portion 122, and as shown in FIG. 7, the disc portion 122 and the semi-cylindrical portion 123 are joined in an eccentric state. Further, the gear cover 24 is formed with a concave portion 125 having a substantially semi-elliptical cross section in accordance with the semi-cylindrical portion 123. The inner dimension of the recess 125 is substantially the same as the outer dimension of the semi-cylindrical part 123.

  Such a shaft cover 121 is attached to the gear cover 24 in such a manner that the disc portion 122 is inserted into the shaft hole 101 and the semi-cylindrical portion 123 is fitted into the recess 125 having a substantially semi-elliptical cross section. As can be seen from FIGS. 7 and 8, the shaft cover 121 having such a cross-sectional shape is fitted to the recess 125 only in a predetermined positional relationship. For this reason, the mounting position of the shaft cover 121 is uniquely defined without blurring, and the shaft cover 104 can be easily and reliably positioned during the shaft cover assembling work. Improved.

  Also in the shaft cover 121 used in the starting motor of the second embodiment, as in the first embodiment, when the semi-cylindrical portion 123 and the concave portion 125 are fitted, the flat portion 114 of the shaft cover 121 becomes the end surface 115 of the gear cover 24. And become the same. Therefore, when the shaft cover 121 is fitted and attached to the gear cover 24, the flat surface portion 114 and the end surface 115 are flush with each other, and the gap between the gasket and the shaft cover 121 is not generated by the protrusion of the shaft cover 121. . Also, in the shaft cover 121, the bellows portion 124 is in intimate contact with the inner peripheral surface 126 of the recess 125 when attached to the gear cover 24, so that the sealing performance at the shaft cover portion is improved.

  Next, a starter motor that is Embodiment 3 of the present invention will be described. FIG. 9 is a perspective view showing a configuration of a shaft cover 131 used in a starting motor that is Embodiment 3 of the present invention, and FIG. 6 is an explanatory view showing a state in which the shaft cover 131 is attached. In the third embodiment, the configuration is the same as that of the first embodiment except for the configuration of the shaft cover 131 and its attachment portion.

  As shown in FIG. 9, the shaft cover 131 is also formed of a circular disc part 132 and a semi-cylindrical part 133 having a semicircular cross section, and a bellows part 134 is formed on the outer periphery of the semi-cylindrical part 133. Yes. However, in the shaft cover 131 used in the present embodiment, a pair of fitting pieces 135 project from the outer periphery of the semi-cylindrical portion 133. The fitting piece 135 is formed in a rectangular flat plate shape, and the lower surface side in FIG. 9 is flush with the flat portion 114 of the semi-cylindrical portion 133. The fitting piece 135 is radially extended from the outer peripheral end of the semi-cylindrical portion 133 (the end of the semicircular outer peripheral arc and both ends of the string) in a wing shape, and is semi-finished along the axial direction. The cylindrical portion 133 is provided over the entire lower end portion. Accordingly, when the semi-cylindrical portion 133 is viewed from the direction indicated by the arrow Z, a square shape is formed by combining the flat portion 114 and the fitting piece 135.

  On the other hand, the gear cover 24 is formed with a recess 136 for attaching the shaft cover 131. The recess 136 is formed on the semicircular cross section 136 where the semicircular cross section of the semicylindrical part 133 is mounted, and on the outside of the semicircular cross section 136 (on the end face 115 side of the gear cover 24), and the fitting piece 135 is mounted. And a fitting groove 137. Such a shaft cover 131 is a gear cover in which the disc portion 132 is inserted into the shaft hole 101, the semi-cylindrical portion 123 is fitted into the semicircular cross-sectional portion 136, and the fitting piece 135 is fitted into the fitting groove 137. 24. At this time, the fitting pieces 135 and the fitting grooves 137 that are formed in a rectangular shape are fitted only in a predetermined positional relationship. For this reason, the mounting position of the shaft cover 131 is uniquely defined without blurring, and the shaft cover 131 can be easily and reliably positioned during the shaft cover assembling work. Improved.

  In the shaft cover 131 used in the starting motor of the third embodiment, when the shaft cover 131 is mounted in the recess 136, the flat portion 114 of the shaft cover 131 including the fitting piece 135 is flush with the end surface 115 of the gear cover 24. Become. Therefore, when the shaft cover 131 is fitted and attached to the gear cover 24, the flat surface portion 114 and the end surface 115 are flush with each other, and the gap between the gasket and the shaft cover 131 is not generated by the protrusion of the shaft cover 131. . In the shaft cover 131 as well, when the shaft cover 131 is attached to the gear cover 24, the bellows portion 134 is in close contact with the inner peripheral surface 138 of the recess 136, so that the sealability at the shaft cover portion is improved.

  It goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

  For example, in the above-described embodiment, the configuration in which the fitting mounting portion 109, the fitting mounting portion 112, the fitting piece 135, and the fitting groove 137 are formed in a square shape is shown, but those shapes are not limited to a square shape, Polygons such as triangles and pentagons can be used as appropriate. Further, the fitting mounting portion 109 and the fitting mounting portion 112 may have an eccentric elliptical shape as in the starting motor of the second embodiment. Furthermore, the fitting piece 135 and the fitting groove 137 may be formed in a U shape with a circular tip at the end instead of a square shape.

  In the above-described embodiment, the starter motor is shown in which the overrunning clutch 13 is attached to the pinion shaft 32 that is rotated by the motor 11 via the planetary gear mechanism 12, but the overrunning clutch is attached to the tip of the motor shaft 27. The present invention can also be applied to a starter motor having a configuration in which the idle gear is mounted, or a starter motor having a configuration in which the idle gear is moved by a lever or the like.

It is sectional drawing which shows the structure of the starting motor which is Example 1 of this invention. It is a perspective view which shows the structure of the shaft cover used for the starting motor of FIG. 2 is a side view of the shaft cover. It is explanatory drawing which shows the attachment state of the shaft cover of FIG. It is explanatory drawing which shows the modification of the shaft cover of FIG. It is a perspective view which shows the structure of the shaft cover used for the starter motor which is Example 2 of this invention. It is a top view of the shaft cover of FIG. It is explanatory drawing which shows the attachment state of the shaft cover of FIG. It is a perspective view which shows the structure of the shaft cover used for the starter motor which is Example 3 of this invention. It is explanatory drawing which shows the attachment state of the shaft cover of FIG. It is explanatory drawing which shows the structure of the conventional starter motor. It is a perspective view which shows the structure of the idle part in the starting motor of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Starter motor 2 Motor part 3 Gear part 4 Magnet switch part 5 Case part 6 Idle part 11 Motor 12 Planetary gear mechanism 13 Overrunning clutch 14 Pinion gear 15 Idle gear 16 Ring gear 21 Motor housing 22 Armature 23 End cover 24 Gear cover 25 Set bolt 26 Permanent magnet 27 Motor shaft 28 Armature core 29 Armature coil 31 Metal bearing 32 Pinion shaft 33 Bearing portion 34 Metal bearing 35 Commutator 36 Commutator piece 37 Brush holder 38 Brush housing portion 39 Brush 41 Conductive plate 42 Switch portion 43 Switch plate 44 Power supply terminal 45 Switch shaft 46 Internal gear unit 47 Drive plate unit 48 Internal gear 49 Metal bearing 5 Planetary gear 52 Base plate 53 Support pin 54 Metal bearing 55 Sun gear 56 Clutch outer 56a Boss part 56b Clutch part 57 Clutch inner 58 Roller 59 Clutch spring 61 Helical spline part 62 Spline part 63 Stopper 64 Circlip 65 Gear return spring 66 Inner end wall 67 Clutch stopper 68 Clutch cover 69 Clutch washer 71 Gear part 72 Pinion washer 73 C ring 74 Shaft hole 75 Spring accommodating part 76 Pinion gear metal 77 Fixed part 78 Movable part 79 Case 81 Coil 82 Fixed iron core 83 Movable iron core 84 Gear plunger 85 Bracket plate 86 Plunger spring 87 Sliding iron core 88 Metal bearing 89 Idle shaft 90 Switch return spring 91 Metal bearing Second gear portions 93 boss 94 the boss portion 95 the flange portion 96 collar 97 C-ring 98 bearing portion
100 Idle gear mounting
101 shaft hole
102 Shaft hole
103 Fixing screw
104 Shaft cover
105 recess
106 disc
107 Semi-cylindrical part
108 Semicircular cross section
109 Mating mount
110 square section
111 Partial circular section
112 Mating attachment
112a square section
112b Circumferential cross section
113 bellows
114 Plane section
115 End face
116 Inner surface
117 protrusion
118 Shaft cover
121 Shaft cover
122 disc
123 Semi-cylindrical part
124 bellows
125 recess
126 Inner surface
131 Shaft cover
132 disc
133 Semi-cylindrical part
134 Bellows
135 Mating piece
136 recess
137 Mating groove
138 Inner surface
201 Starter motor
202 Motor section
203 Gear
204 Magnet switch
205 Case
206 Idol Club
211 motor
212 Planetary gear mechanism
213 Overrunning clutch
214 pinion gear
215 idle gear
216 idle shaft
217 ring gear
218 Helical spline section
219 Gear cover
221 Bearing
222 Bearing
223 fixing screw
224 Shaft cover
225 disc
226 Semi-cylindrical part
227 recess
228 Plane section
229 End face

Claims (6)

An idle gear that is rotationally driven by an electric motor and meshes with an engine ring gear by moving in an axial direction;
An idle shaft that supports the idle gear so as to be rotatable and movable in the axial direction;
A cover member that is attached to the engine and includes a shaft hole through which the idle shaft is inserted, and a recess formed facing the shaft hole;
A starter motor having a shaft cover attached to the recess and covering one end side of the idle shaft;
The shaft cover includes a disc portion mounted in the shaft hole, a semi-cylindrical portion that is formed integrally with the disc portion and extends in the axial direction, and an end portion of the semi-cylindrical portion. A semi-cylindrical part and a fitting attachment part having a polygonal cross section formed integrally;
The concave portion has a semicircular cross-sectional portion that is formed in a substantially semicircular cross-section and to which the semi-cylindrical portion is mounted, and an angular cross-sectional portion that is formed in a polygonal cross-section and engages with the fitting attachment portion. Start motor.   2. The starter motor according to claim 1, wherein the fitting attachment portion is added to an outer periphery of the semi-cylindrical portion.   2. The starter motor according to claim 1, wherein the fitting attachment portion extends in an axial direction from an end portion of the semi-cylindrical portion. An idle gear that is rotationally driven by an electric motor and meshes with an engine ring gear by moving in an axial direction;
An idle shaft that supports the idle gear so as to be rotatable and movable in the axial direction;
A cover member that is attached to the engine and includes a shaft hole through which the idle shaft is inserted, and a recess formed facing the shaft hole;
A starter motor having a shaft cover attached to the recess and covering one end side of the idle shaft;
The shaft cover includes: a disc portion mounted in the shaft hole; and a semi-cylindrical portion having a semi-elliptical cross section formed integrally with the disc portion and extending in the axial direction in an eccentric state with the disc portion. Have
The starter motor is characterized in that the recess is formed in a semi-elliptical cross section that fits into the semi-cylindrical part. An idle gear that is rotationally driven by an electric motor and meshes with an engine ring gear by moving in an axial direction;
An idle shaft that supports the idle gear so as to be rotatable and movable in the axial direction;
A cover member that is attached to the engine and includes a shaft hole through which the idle shaft is inserted, and a recess formed facing the shaft hole;
A starter motor having a shaft cover attached to the recess and covering one end side of the idle shaft;
The shaft cover includes a disc portion mounted in the shaft hole, a semi-cylindrical portion that is formed integrally with the disc portion and extends in the axial direction, and an outer peripheral end portion of the semi-cylindrical portion. Having a fitting piece formed and extending in the radial direction,
The starter motor is characterized in that the recess has a semicircular cross section formed in a substantially semicircular cross section and fitted with the semicylindrical part, and a fitting groove fitted into the fitting piece.   The starter motor according to any one of claims 1 to 5, wherein the shaft cover further includes a bellows portion formed on an outer periphery of the semi-cylindrical portion and provided with a plurality of irregularities along the axial direction. A starting motor characterized by that.

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