JP2008240539A - Starting motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce cost by reducing a processing process of an idle shaft, and to increase efficiency in idle shaft installing work. <P>SOLUTION: A shaft hole 102 for inserting the idle shaft 89 is arranged in a bearing part 99 of a gear cover 24. A pin hole 103 is formed in the innermost part of the shaft hole 102. A rotation preventive pin 105 is pressed in and fixed to the pin hole 103. A step part 104 is formed in an end part of the idle shaft 89, and the rotation preventive pin 105 is inserted into the step part 104. A slipping-out preventive screw 106 is installed in a bearing part 98 of the gear cover 24 by facing a shaft hole 101. A head part 108 of the slipping-out preventive screw 106 is allowed to abut on an end surface 89a of the idle shaft 89. The idle shaft 89 is prevented from rotating by the rotation preventive pin 105, and is installed in the gear cover 24 in a slipping-out prevented state by the slipping-out preventive screw 106. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a starter motor attached to an engine such as an automobile, and more particularly to a starter motor provided with an idle gear that is rotationally driven by an electric motor and movable in an axial direction.

  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. 4 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 as a driving source, and the gear unit 203 is provided with a planetary gear mechanism 212, an overrunning clutch 213, a pinion gear 214 and the like as speed reducers. The idle portion 206 is provided with an idle gear 215 that meshes with the pinion gear 214. The idle gear 215 is accommodated in a gear cover 219 of the case portion 205, and is rotatably attached to an idle shaft 220 attached to the gear cover 219. The idle gear 215 is movable in the axial direction (left and right direction in the figure), and meshes with the ring gear 216 of the engine when moved in the left direction in the figure. The right end surface of the idle gear 215 in the drawing is in contact with a flange portion 217 formed on the pinion gear 214.

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. As a result, the idle gear 215 meshes with the ring gear 216, the rotational force of the motor 211 is transmitted to the ring gear 216 via the idle gear 215, and the engine is started.
JP 2006-274874 A

  On the other hand, in such a starter motor, the idle shaft 220 is fixed to the gear cover 219 by a fixing screw 221 as shown in FIG. However, in the case of such a screwing structure, various processes such as a screw insertion hole of the idle shaft 220 and a female screw hole of the gear cover 219 are required. FIG. 5 is an explanatory view showing the machining process of the idle shaft 220. Here, first, in (1) the cutting / forging step, the rod-shaped blank material is cut into a predetermined length, and a screw hole index 222 indicating the screw hole forming direction is provided in a concave shape on one end face. At the same time, a planar insertion hole forming part 223 is formed at the end of the shaft. Thereafter, (2) in the first cutting process, a screw insertion hole 224 is formed in the insertion hole forming portion 223 and a chamfering process is performed on one side (front side) of the screw insertion hole 224 (chamfering process (a)). ). After performing the first cutting, (3) in the second cutting step, the other side (back side) of the screw insertion hole 224 is chamfered (chamfering (b)). After finishing these processes, (4) heat treatment is performed, and (5) the shaft surface is finished by grinding to form the idle shaft 220.

  A fixing screw insertion hole 225 and a female screw hole 226 are also formed on the gear cover 219 side in order to screw the idle shaft 220 with screws. The idle shaft 220 is inserted into a shaft hole 227 formed in the gear cover 219, and a fixing screw 221 is inserted in this state. The fixing screw 221 is screwed into the female screw hole 226, whereby the idle shaft 220 is fixed to the gear cover 219. As described above, in order to fix the idle shaft 220 to the gear cover 219 with screws, a number of processing steps are required. For this reason, the starter motor as shown in FIG. 4 has a problem that the processing cost increases and the product cost increases.

  Further, in the starting motor shown in FIG. 4, when screwing the idle shaft 220, the screw insertion hole 224 cannot be directly viewed from the outside. For this reason, although the screw shaft index 222 is provided on the idle shaft 220 to improve workability, it is still difficult to align the screw holes from the outside of the gear cover 219, and there is a problem that the assemblability is not good. It was. Furthermore, since the idle shaft 220 is fixed from the radial direction, the idle shaft 220 is likely to be misaligned, and there is a possibility that the operating noise during starter operation may increase or vibration noise may occur due to vehicle vibration. there were.

  An object of the present invention is to reduce costs by reducing idle shaft machining steps and to improve the efficiency of idle shaft fixing work. Another object of the present invention is to suppress the misalignment of the idle shaft and reduce the starter operating noise.

  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 starter motor attached to an engine and having cover members for supporting both end portions of the idle shaft, wherein the cover member is formed with an engagement portion formed in a cutout at one end side of the idle shaft and extending in the axial direction. A detent member attached to one end side of the idle shaft and inserted into the engaging portion; and a retaining member attached to the other end side of the idle shaft of the cover member and contacting the other end side end surface of the idle shaft And a member.

  In the present invention, an engaging portion is formed at the end of the idle shaft, and a non-rotating member is inserted into the engaging portion, and a retaining member that contacts the other end surface of the idle shaft is disposed on the cover member. Thus, the idle shaft is prevented from being rotated by the rotation preventing member and is attached to the cover member in a state of being prevented from being removed by the retaining member. This simplifies the configuration of the idle shaft and eliminates the need for threading and chamfering of the screw insertion hole that is carried out when manufacturing the idle shaft, thereby simplifying the machining process and reducing machining costs. It is done. In addition, the idle shaft can be assembled by inserting the idle shaft with the anti-rotation member attached to the cover member, and then attaching the retainer member, so that the idle shaft can be assembled easily. Improvement of sex is also achieved. Further, the idle shaft can be easily centered and misalignment is unlikely to occur.

  In the starting motor, a pin that can be inserted into the engaging portion may be used as the rotation preventing member, and a pin hole in which the pin can be attached may be provided in the cover member. Further, as the retaining member, a screw member capable of abutting against the other end face of the idle shaft may be used, and a screw hole to which the screw member can be attached may be provided in the cover member.

  According to the starter motor of the present invention, 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, an idle shaft that supports the idle gear rotatably and axially, and the engine A starter motor having a cover member that supports both ends of the idle shaft, and an engagement portion is cut out at one end of the idle shaft, and a detent member inserted into the engagement portion is provided. As well as being attached to the cover member, a retaining member that abuts against the other end surface of the idle shaft is attached to the cover member, so that the configuration of the idle shaft is simplified and the screw insertion hole is cut when the idle shaft is manufactured. Processing and chamfering can be omitted. Therefore, the idle shaft machining process is simplified, and the machining cost can be reduced.

  In addition, since the idle shaft can be assembled by inserting the idle shaft with the anti-rotation member attached to the cover member and then attaching the retainer member, the assembly work of the idle shaft is facilitated, and the conventional configuration As a result, it is possible to improve the assemblability. Further, since the idle shaft can be easily centered and misalignment is unlikely to occur, it is possible to reduce operating noise and vibration noise, and to reduce the noise of the apparatus.

  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 starting motor according to an embodiment 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. The motor unit 2 is provided with a motor (electric motor) 11 as a driving source, and the gear unit 3 is provided with a planetary gear mechanism 12, a overrunning clutch 13, a pinion gear 14 and the like as speed reducers. 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 an 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 disposed 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 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. A pin hole 103 is further formed in the inner portion of the shaft hole 102 so as to penetrate the bearing portion 99 in the axial direction. The pin hole 103 has a diameter slightly smaller than half the diameter of the shaft hole 102 and is provided on the lower end side of the shaft hole 102 in FIG. On the other hand, a stepped portion (engaging portion) 104 is notched at the end of the idle shaft 89 on the bearing portion 99 side. The step portion 104 has a D-cut cross section, and extends along the axial direction from the right end of the idle shaft 89 in the drawing. The height dimension h in the radial direction of the stepped portion 104 is slightly larger than the diameter d of the pin hole 103.

  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. FIG. 2 is a cross-sectional view showing a state of the idle shaft 89 inserted into the gear cover 24, and corresponds to a cross section taken along the line AA in FIG. As shown in FIGS. 1 and 2, in the starter motor 1, a rotation prevention pin (rotation prevention member) 105 is inserted into the step portion 104 of the idle shaft 89, and the rotation of the idle shaft 89 is caused by the rotation prevention pin 105. Being regulated. Here, first, the non-rotating pin 105 is press-fitted and fixed in the pin hole 103, and the idle shaft 89 is inserted into the gear cover 24 in this state. Then, the idle shaft 89 is appropriately rotated, the positions of the anti-rotation pin 105 and the stepped portion 104 are aligned, and the idle shaft 89 is inserted deep into the shaft hole 102. As described above, since the size of the step portion 104 is slightly larger than the diameter of the pin hole 103, the detent pin 105 is inserted into the step portion 104, whereby the idle shaft 89 is prevented from rotating with respect to the gear cover 24. .

  On the other hand, a retaining screw (a retaining member; screw member) 106 is attached to the bearing portion 98 side in order to prevent the idle shaft 89 from coming off. The retaining screw 106 is attached at a position facing the shaft hole 101, and is fixed to the bearing portion 98 such that its head portion 108 projects in front of the shaft hole 101. The retaining screw 106 is attached to the bearing portion 98 after the idle shaft 89 is inserted into the shaft hole 101 and the shaft hole 102 and the rotation prevention pin 105 is engaged with the stepped portion 104. A screw hole 107 is provided in the bearing portion 98 so as to face the shaft hole 101, and the retaining screw 106 is screwed and fixed to the screw hole 107. When the retaining screw 106 is attached to the screw hole 107, the head portion 108 is disposed at a position facing the end surface 89a of the idle shaft 89 on the bearing portion 98 side, as shown in FIG. The movement of the idle shaft 89 in the left direction in the figure is restricted by the end surface 89 a coming into contact with the head portion 108, whereby the idle shaft 89 is prevented from being detached from the gear cover 24.

  Thus, the idle shaft 89 is attached to the gear cover 24 in a state in which the idle shaft 89 is prevented from being rotated by the rotation preventing pin 105 and is prevented from being removed by the retaining screw 106. And, when such an idle shaft mounting structure is adopted, the configuration of the idle shaft is simplified as compared with the case of adopting the conventional mounting structure, and the screw insertion hole cutting process and the chamfering process of the idle shaft become unnecessary. Therefore, the machining process is simplified and the assembly of the shaft is improved. FIG. 3 is an explanatory view showing the machining process of the idle shaft 89. Here, first, (1) in the cutting and forging step, the rod-shaped blank material is cut into a predetermined length, and a stepped portion 104 is formed at one end. Then, after the cutting / forging process, (2) heat treatment is performed, and (3) the shaft surface is finished by grinding to form an idle shaft 89.

  As is apparent from a comparison between FIG. 2 and FIG. 5, the idle shaft 89 does not require the first and second cutting processes (2) and (3) in FIG. In other words, the production of the idle shaft can be reduced to 3 processes, which conventionally required 5 processes. Further, the idle shaft 89 is not cut and can be manufactured entirely by press processing. Therefore, it is possible to reduce the number of manufacturing steps of the idle shaft 89 as compared with the prior art, and to reduce the shaft processing cost.

  In addition, since the idle shaft 89 is inserted in the state in which the rotation prevention pin 105 is attached to the gear cover 24 and then the retaining screw 106 is attached, the assembly work of the idle shaft 89 is easy and the assembling property is improved. Is also planned. Furthermore, since the center position accuracy of the idle shaft 89 depends solely on the accuracy of the shaft hole 101 and the shaft hole 102, centering is easy, and since there is no restriction from the radial direction, misalignment hardly occurs. For this reason, the operation sound at the time of starter operation | movement and the vibration sound by vibration of a vehicle can be reduced, and the apparatus can be silenced.

  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. In the starter motor 1, even when the idle gear 15 moves, the idle shaft 89 has little misalignment and the pitch accuracy between the idle gear 15 and other gears is high, so that the operation noise and vibration noise are small. It can be suppressed.

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 example in which the D-cut stepped portion 104 is formed as the engagement portion to be cut out on one end side of the idle shaft is shown, but the shape of the engagement portion is not limited to this. Alternatively, a key groove shape or a hole shape may be used. Moreover, although the example which uses the non-rotation pin 105 as a detent | locking member was shown, this may also use things other than a pin. For example, the pin hole 103 may be formed in a female screw hole, and a screw member may be screwed into the female screw hole and inserted into the engaging portion. Further, the retaining member may be a pin or the like instead of the retaining screw 106.

  On the other hand, in the above-described embodiment, the starter motor in which the overrunning clutch 13 is attached to the pinion shaft 32 rotated by the motor 11 via the planetary gear mechanism 12 is shown. 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 one Example of this invention. It is sectional drawing along the AA line of FIG. It is explanatory drawing which shows the process of an idle shaft. It is explanatory drawing which shows the structure of the conventional starter motor. It is explanatory drawing which shows the process of an idle shaft in the conventional starter motor.

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 (cover member)
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 accommodating portion 39 brush 41 conductive plate 42 switch portion 43 switch plate 44 Power terminal 45 Switch shaft 46 Internal gear unit 47 Drive plate unit 48 Internal gear 49 Metal bearing 51 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 Pulling 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 89a End face 90 Switch return spring 91 Metal bearing 92 Gear portion 93 Boss portion 94 Boss portion 95 Flange portion 96 Collar 97 C ring 98 Bearing portion 99 Bearing portion
100 Idle gear mounting
101 shaft hole
102 Shaft hole
103 pin hole
104 Step (engagement part)
105 Non-rotating pin (non-rotating member)
106 Retaining screw (Retaining member; Screw member)
107 Screw hole
108 head
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 ring gear
217 Flange
218 Helical spline section
219 Gear cover
220 Idle shaft
221 fixing screw
222 Screw hole index
223 Insertion hole forming part
224 Screw insertion hole
225 fixing screw insertion hole
226 Female screw hole
227 Shaft hole

Claims (3)

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 starting electric motor having a cover member attached to the engine and supporting both end portions of the idle shaft;
An engagement part formed in a cutout on one end side of the idle shaft and extending in the axial direction;
A detent member attached to one end side of the idle shaft of the cover member and inserted into the engagement portion;
A starter motor having a retaining member attached to the other end side of the idle shaft of the cover member and abutting against an end surface of the other end side of the idle shaft.   2. The starter motor according to claim 1, wherein the detent member is a pin that can be inserted into the engaging portion, and the cover member has a pin hole to which the pin can be attached. Electric motor.   3. The starter motor according to claim 1, wherein the retaining member is a screw member capable of contacting the other end surface of the idle shaft, and the cover member is a screw to which the screw member can be attached. A starter motor having a hole.

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