JP2015190437A - Stater and method of assembling starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a starter capable of easily carrying out assembling work, and a method of assembling the starter.SOLUTION: A starter includes: a motor portion 3; a drive shaft 4 rotated by receiving the rotational force of the motor portion 3; a transmission pinion gear 70 provided on the drive shaft 4; an idle shaft 102 extending in a parallel direction with the drive shaft 4; an idle gear 101 provided on the idle shaft 102, and engaged with the transmission pinion gear 70; a drive pinion gear 110 provided on the idle shaft 102, and capable of being engaged with a ring gear of an engine; a gear cover 172 rotatably supporting a part of the drive shaft 4 and the idle shaft 102, and storing the transmission pinion gear 70 and the idle gear 101; and a bracket portion 171 provided between the motor portion 3 nd the gear cover 172, and rotatably supporting an axial one end of the idle shaft 102.

Description

  The present invention relates to a starter and a starter assembling method.

  For example, in a starter used for starting an engine of an automobile, a motor unit that generates a rotational force by energization, a drive shaft that rotates by receiving the rotational force of the motor unit, and a ring gear of the engine can be engaged and disengaged. A drive pinion gear that is provided and transmits the rotational force of the drive shaft to the ring gear, and an electromagnetic device that energizes and shuts off the motor unit and generates a pressing force toward the ring gear on the drive pinion gear. There is what I did.

Here, the drive pinion gear may be slidably provided on the drive shaft, or may be provided slidably on an idle shaft extending in a direction parallel to the drive shaft for convenience of a starter layout or the like.
A so-called two-axis type starter having two shafts, a drive shaft and an aisle shaft, is provided with a transmission pinion gear on the drive shaft and an idle gear meshed with the transmission pinion gear on the idle shaft. Thereby, the rotational force of a drive shaft can be transmitted to a ring gear via an idle gear (for example, refer patent document 1).

International Publication No. 2007/034666

  By the way, in the above-mentioned two-axis type starter, since the drive shaft and the aisle shaft are arranged in parallel, it is necessary to assemble two shafts when assembling the starter, and one drive shaft Is supported by the base plate and the gear cover, and the other idle shaft is supported by the gear cover at both ends. For this reason, after installing the drive shaft and pinion in the gear cover, it is necessary to incorporate the idle shaft into the gear cover while holding the idle gear so as to mesh with the pinion. is there.

  Therefore, the present invention has been made in view of the above-described circumstances, and provides a starter and a starter assembling method capable of easily performing an assembling operation.

  In order to solve the above-described problems, a starter according to the present invention includes a motor unit that generates a rotational force when energized, a drive shaft that rotates in response to the rotational force of the motor unit, and a sliding movement on the drive shaft. A transmission gear provided on the drive shaft, and an idle shaft that extends in a direction parallel to the drive shaft, is rotatable about a central axis, and is slidable in the central axis direction in conjunction with the sliding movement of the transmission gear. An idle gear that is provided on one end side in the axial direction of the idle shaft and meshes with the transmission gear, a drive gear that is provided on the other end side in the axial direction of the idle shaft and meshes with the ring gear of the engine, and the drive shaft And a part of the idle shaft that rotatably supports the transmission gear and the idle gear. A gear cover section to containers, provided between the motor unit and the gear cover section, characterized in that it and a bracket portion for rotatably supporting the axial end of the idle shaft.

Thus, the member that rotatably supports the drive shaft and the idle shaft, the gear cover that rotatably supports a part of the drive shaft and the idle shaft, and the bracket portion that rotatably supports one end of the idle shaft in the axial direction, Further, a motor part is provided separately from the gear cover and the bracket part. For this reason, positioning of a drive shaft and an idle shaft can be performed easily, and assembly work of a starter can be facilitated.
Further, it is possible to provide a starter capable of adjusting a torque-oriented type or a rotation-oriented type by changing the gear ratio between the transmission gear and the idle gear.

  The starter according to the present invention is characterized in that the other axial end side of the idle shaft protrudes axially outward from the gear cover portion, and the drive gear is provided at the protruding portion.

  By comprising in this way, other gears except a drive gear can be sealed with a gear cover, a bracket part, and a motor part. For this reason, it becomes possible to reliably prevent the meshing failure between the gears and the damage of the bearing due to dust or the like.

  The starter according to the present invention is characterized in that the idle shaft and the idle gear are integrally formed.

  With this configuration, the number of parts can be reduced. For this reason, the assembling work of the starter can be further facilitated.

  The starter according to the present invention is provided between the transmission gear and the motor unit, and is provided in the bracket unit, a clutch mechanism that transmits and blocks the rotational force of the drive shaft to the transmission gear, and the motor unit. And an electromagnetic device for generating a pressing force toward the ring gear on the drive gear via the clutch mechanism.

  With this configuration, it is possible to prevent an extra load such as a reverse force being generated in the motor unit when the drive shaft rotates at a higher speed than the motor unit. In addition, the drive gear can be reliably engaged with the ring gear using the electromagnetic device. For this reason, a starter with high operation reliability can be provided.

  The electromagnetic device in the starter according to the present invention includes an excitation coil, and a gear plunger that slides along the drive shaft based on energization of the excitation coil and generates a pressing force in the clutch mechanism, It is provided coaxially with the drive shaft.

  With this configuration, the structure of the electromagnetic device can be simplified and reduced in size, and the space for arranging the electromagnetic device can be saved.

  In the starter according to the present invention, the bracket portion is assembled as a subunit in a state where the electromagnetic device is assembled in the bracket portion and the motor portion is assembled, and the bracket portion is moved from the bracket portion to the gear cover portion side. It is characterized by having a retaining portion for restricting the electromagnetic device from coming off.

  With this configuration, the motor unit and the electromagnetic device can be assembled into a subunit in which the electromagnetic device cannot be removed in advance, and a gear cover, a drive shaft, and an idle shaft can be assembled to the subunit. . Thus, since each can be assembled | attached separately, the assembly operation | work of a starter can be further facilitated.

  The starter according to the present invention is characterized in that a drainage portion is provided on a contact surface between the gear cover portion and the bracket portion.

  By comprising in this way, even if it is a draining part of a complicated shape like a labyrinth structure, it can comprise easily and the water which permeated in the gear cover part or the bracket part can be discharged | emitted rapidly outside. For this reason, a starter with higher operational reliability can be provided.

  The starter according to the present invention is characterized in that a drainage groove is formed in the contact surface of the bracket portion, and the drainage portion is configured by the drainage groove and the contact surface of the gear cover portion. To do.

  With this configuration, even when the gear cover portion is changed due to a specification change or the like, the drainage portion can be easily configured on the contact surface between the gear cover portion and the bracket portion. For this reason, the manufacturing cost of a starter with high operation reliability can be reduced.

  In the starter assembly method according to the present invention, the drive cover, the transmission gear, the idle gear, and the idle shaft are assembled in advance to the gear cover portion, and after the preliminary assembly step, the gear cover portion A bracket part assembling step for assembling the bracket part.

  By setting it as such a method, since a drive shaft and an idle shaft can be previously fixed to the gear cover part, positioning of these two shafts becomes easy. For this reason, the assembling work of the starter can be facilitated.

  The starter assembling method according to the present invention includes an electromagnetic device assembling step of assembling an electromagnetic device that generates a pressing force toward the ring gear on the drive gear before the bracket portion assembling step, The bracket part assembling step is performed in a state where the electromagnetic device is assembled to the bracket part by the electromagnetic apparatus assembling step.

  By adopting such a method, the assembling work of the starter can be further facilitated.

  According to the present invention, the member that rotatably supports the drive shaft and the idle shaft, the gear cover that rotatably supports a part of the drive shaft and the idle shaft, and the bracket that rotatably supports one axial end of the idle shaft. In addition, the motor part is provided separately from the gear cover and the bracket part. For this reason, positioning of a drive shaft and an idle shaft can be performed easily, and assembly work of a starter can be facilitated.

It is sectional drawing of the starter in embodiment of this invention. It is a component expanded view which shows schematic structure of the starter in embodiment of this invention. It is the perspective view which looked at the bracket part in embodiment of this invention from the gear cover side. It is the perspective view which looked at the gear cover in the embodiment of the present invention from the bracket part side. It is the top view which looked at the state which assembled | attached the gear cover, bracket part, and motor part in embodiment of this invention from the gear cover side. It is the top view which looked at the state which assembled | attached the gear cover, bracket part, and motor part in embodiment of this invention from the motor part side. It is the perspective view which looked at the state which assembled | attached the gear cover, bracket part, and motor part in embodiment of this invention from diagonally lower side. It is an expanded sectional view of the idle gear unit in the embodiment of the present invention. It is a perspective view of the switch plunger in the embodiment of the present invention. It is sectional drawing of the switch plunger in embodiment of this invention. It is the A section enlarged view of FIG. It is explanatory drawing which shows the assembly | attachment procedure of the starter in embodiment of this invention, Comprising: (a)-(d) shows each process. It is explanatory drawing which shows the generation | occurrence | production state of the magnetic flux around a switch plunger and a gear plunger in embodiment of this invention.

(Starter)
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a cross-sectional view of a starter, and FIG.
As shown in FIGS. 1 and 2, the starter 1 is for generating a rotational force necessary for starting an engine (not shown), and includes a motor unit 3 and one of the motor units 3 (the left side in FIG. 1). ), A clutch mechanism 5 provided on the drive shaft 4 so as to be slidable, and an idle gear unit 100 for transmitting the rotational force of the drive shaft 4 to a ring gear 23 of an engine (not shown). The switch unit 7 opens and closes the power supply path to the motor unit 3, and the electromagnetic device 9 moves the movable contact plate 8 of the switch unit 7 along the axial direction.

(Motor part)
The motor unit 3 is connected to the brushed DC motor 51 and the rotating shaft 52 of the brushed DC motor 51, and the planetary gear mechanism 2 as a reduction mechanism for transmitting the rotational force of the rotating shaft 52 to the drive shaft 4. It is comprised by.
The brushed DC motor 51 includes a substantially cylindrical motor yoke 53, and an armature 54 that is disposed on the radially inner side of the motor yoke 53 and is rotatable with respect to the motor yoke 53. A plurality (for example, six in the present embodiment) of permanent magnets 57 are provided on the inner peripheral surface of the motor yoke 53 so that the magnetic poles alternate in the circumferential direction.

At the other end (right side in FIG. 1) of the motor yoke 53, an end plate 55 for closing the opening 53a of the motor yoke 53 is provided. At the center in the radial direction of the end plate 55, a sliding bearing 56a and a thrust bearing 56b for rotatably supporting the other end of the rotating shaft 52 are provided.
The armature 54 includes an armature core 58 that is externally fitted and fixed at a position corresponding to the permanent magnet 57 of the rotating shaft 52, and the planetary gear mechanism 2 side of the armature core 58 of the rotating shaft 52 (in FIG. 1). And a commutator 61 that is externally fitted and fixed to the left side).

  The armature core 58 has a plurality of teeth (not shown) formed radially and a plurality of slots (not shown) formed between the teeth adjacent in the circumferential direction. A coil 59 is wound by, for example, wave winding between each slot spaced a predetermined distance in the circumferential direction. The terminal portion of the coil 59 is drawn toward the commutator 61.

The commutator 61 is provided with a plurality of (for example, 26 in the present embodiment) segments 62 along the circumferential direction and at a predetermined interval so as to be electrically insulated from each other.
A riser 63 that is bent so as to be folded is provided at the end of each segment 62 on the armature core 58 side. A terminal part of a coil 59 wound around the armature core 58 is connected to the riser 63.

On the opposite side of the motor yoke 53 from the end plate 55, a bottomed cylindrical top plate 12 is provided. The planetary gear mechanism 2 is provided on the inner surface of the top plate 12 on the armature core 58 side.
The planetary gear mechanism 2 includes a sun gear 13 formed integrally with a rotating shaft 52, a plurality of planetary gears 14 that mesh with the sun gear 13 and revolve around the sun gear 13, and an annular inner gear provided on the outer peripheral side of the planetary gears 14. The tooth ring gear 15 is used.

  The plurality of planetary gears 14 are connected by a carrier plate 16 as an output unit. The carrier plate 16 is provided with a plurality of support shafts 16a at positions corresponding to the planetary gears 14, and the planetary gears 14 are rotatably supported thereon. Further, an engagement hole 16b having a serration is provided at the radial center of the carrier plate 16, and the serration portion 4e of the other end 4d of the drive shaft 4 is engaged by serration engagement.

  The internal ring gear 15 is integrally formed on the inner surface of the top plate 12 on the armature core 58 side. A sliding bearing 12 a is provided at the radial center of the inner peripheral surface of the top plate 12. The plain bearing 12a rotatably supports the other end portion 4d of the drive shaft 4 that is disposed coaxially with the rotary shaft 52.

(housing)
As described above, the top plate 12 on which the planetary gear mechanism 2 is provided is housed and fixed in the housing 17. The housing 17 has a role of fixing the starter 1 to an engine (not shown) and a role of housing the top plate 12 (planetary gear mechanism 2), the electromagnetic device 9, the clutch mechanism 5, the idle gear unit 100, and the like.

  The housing 17 is mounted on one side (the left side in FIG. 1) and the other side (the right side in FIG. 1), the bracket part 171 having the openings 171a and 171c, and one of the bracket parts 171 (the left side in FIG. 1). The gear cover 172 is divided. The bracket portion 171 and the gear cover 172 are each made of aluminum and are formed by die casting. And the top plate 12 is provided so that the other opening part 171c of the bracket part 171 may be obstruct | occluded.

  The bracket portion 171 has a female screw portion 171b formed along the axial direction on the outer peripheral surface on the other opening portion 171c side. Further, a bolt hole 55a is formed at a position corresponding to the female screw portion 171b in the end plate 55 disposed on the other side of the motor yoke 53 (the right end side in FIG. 1). By inserting the bolt 95 into the bolt hole 55a and screwing the bolt 95 into the female screw portion 171b, the motor portion 3 and the bracket portion 171 are integrated.

A ring-shaped stopper 94 is provided on the inner wall of the bracket portion 171 to restrict displacement of a clutch outer 18 (described later) toward the motor portion 3 side. The stopper 94 is made of resin, rubber, or the like, and can relieve an impact when the clutch outer 18 abuts.
Further, the inner wall of the bracket portion 171 is provided with a reduced diameter portion 171 d that is formed with a reduced diameter by a step closer to the one opening 171 a than the stopper 94. The stepped surface of the reduced diameter portion 171d functions as a retaining portion for preventing the electromagnetic device 9 from slipping out from one opening 171a in the bracket portion 171.

FIG. 3 is a perspective view of the bracket portion viewed from the gear cover side.
As shown in FIGS. 1 to 3, a shaft hole 174 is formed on the outer side in the radial direction of the opening 171 a on the one opening 171 a side (the front side in FIG. 3) of the bracket portion 171. The shaft hole 174 is for rotatably supporting the vicinity of one end 102a (the left end in FIG. 1) of the idle shaft 102 described later.

  In addition, an outer flange portion 171t projecting outward is integrally formed on the one opening 171a side of the bracket portion 171. A surface of the outer flange portion 171t facing the gear cover 172 is a contact surface (matching surface) 171e with the gear cover 172. A meat stealing portion 169 is formed on the contact surface 171e except for the outer peripheral portion. By forming the meat stealing portion 169, the weight of the bracket portion 171 is reduced, and the processing area of the contact surface 171e can be reduced, thereby reducing the manufacturing cost.

  Here, in a state where the starter 1 is attached to an engine (not shown), the upper side shown in FIG. 3 is the upper side in the vertical direction of the starter 1, and the lower side shown in FIG. In the following description, the lower side in the vertical direction (the lower side shown in FIG. 3) in a state where the starter 1 is attached to the engine (not shown) is simply referred to as the lower side, and the upper side in the vertical direction (the upper side shown in FIG. 3). In some cases, it is simply referred to as the upper side.

  On the contact surface 171e of the outer flange portion 171t, a drain groove 168 is formed at a lower position. The drain groove 168 is for discharging water droplets generated by entering or condensing into the housing 17 to the outside. The drain groove 168 has a labyrinth structure that is bent with respect to the vertical direction. By making the drain groove 168 have a labyrinth structure, it is possible to prevent water from entering the housing 17 from the outside while allowing water droplets to be discharged out of the housing 17.

In addition, a plurality of bolt insertion holes 175 are formed in the outer peripheral portion of the outer flange portion 171t at intervals in the circumferential direction. Furthermore, on the upper side of the outer flange portion 171t, a female screw portion 167 is formed at a position corresponding to a later-described bolt insertion hole 183 of the gear cover 172. The bolt insertion holes 175 and the female screw portions 167 are arranged at substantially equal intervals in the circumferential direction.
Further, a pin insertion hole 166 into which a positioning pin 184 described later of the gear cover 172 can be inserted is formed between the drain groove 168 and the bolt insertion hole 175 below the outer flange portion 171t. The bolt insertion hole 175, the female screw part 167 and the pin insertion hole 166 of the bracket part 171 are used to fix the bracket part 171 and the gear cover 172.

  4 is a perspective view of the gear cover as viewed from the bracket portion side, FIG. 5 is a plan view of the gear cover, the bracket portion and the motor portion as assembled from the gear cover side, and FIG. 6 is a plan view of the gear cover, the bracket portion and the motor portion. It is the top view which looked at the assembled state from the motor part side.

  As shown in FIGS. 1, 2, 4 to 6, the gear cover 172 has a contact surface (matching surface) 172 s that contacts the outer flange portion 171 t of the bracket portion 171 on the side facing the bracket portion 171. doing. On the contact surface 172s, a meat stealing portion 181 is formed at a position corresponding to the meat stealing portion 169 of the bracket portion 171 except for the outer peripheral portion. By forming the meat stealing portion 181, the weight of the gear cover 172 can be reduced, and the processing area of the contact surface 172 s can be reduced, thereby reducing the manufacturing cost.

  Further, a female screw portion 172a is engraved on the outer peripheral portion of the contact surface 172s at a position corresponding to the bolt insertion hole 175 of the bracket portion 171. Further, a flange portion 182 projecting to the outer peripheral side is integrally formed at a position corresponding to the female screw portion 167 of the bracket portion 171 on the outer peripheral portion of the contact surface 172s, and a bolt insertion hole 183 is formed here. Is formed. A positioning pin 184 is press-fitted and fixed to the outer peripheral portion of the contact surface 172s at a position corresponding to the pin insertion hole 166 of the bracket portion 171.

  With this configuration, when the bracket portion 171 and the gear cover 172 are assembled, the positioning pin 184 of the gear cover 172 is inserted into the pin insertion hole 166 of the bracket portion 171, and the contact surface 171 e of the bracket portion 171. The contact surface 172s of the gear cover 172 is overlapped.

  Then, as shown in FIGS. 2, 5, and 6, four bolts 177a are inserted into the bolt insertion holes 175 of the bracket portion 171 from the motor portion 3 side, and these bolts 177a are screwed into the female screw portion 172a of the gear cover 172. Enter. Further, a bolt 177 b is inserted into the bolt insertion hole 183 of the gear cover 172 from the side opposite to the motor portion 3, and the bolt 177 b is screwed into the female screw portion 167 of the bracket portion 171. Thus, the bracket portion 171 and the gear cover 172 are integrated so that the bolts 177a and 177b are fastened from both sides across the contact surface 171e of the bracket portion 171 and the contact surface 172s of the gear cover 172. .

Here, the bolt insertion hole 175, the female screw part 167, the female screw part 172a, and the bolt insertion hole 183 for fastening and fixing the bracket part 171 and the gear cover 172 are arranged at substantially equal intervals in the circumferential direction. ing. For this reason, the fastening and fixing force acts on the bracket portion 171 and the gear cover 172 in a balanced manner in the circumferential direction, and the bracket portion 171 and the gear cover 172 are securely fixed.
Further, the bolts 177a and 177b are fastened from both sides across the contact surface 171e of the bracket portion 171 and the contact surface 172s of the gear cover 172, so that the starter 1 is attached to an engine (not shown). The starter 1 cannot be easily disassembled.

FIG. 7 is a perspective view of a state where the gear cover, the bracket portion, and the motor portion are assembled as seen obliquely from below.
As shown in the figure, since the drainage groove 168 is formed in the lower position on the contact surface 171e of the outer flange portion 171t in the bracket portion 171, the bracket portion 171 and the gear cover 172 are integrated. In this state, a drainage portion (drainage hole) 185 is formed by the drainage groove 168 and the contact surface 172 s of the gear cover 172.

As described above, since the drainage portion 185 is formed between the outer flange portion 171t of the bracket portion 171 and the gear cover 172, water droplets generated by entering or condensing the bracket portion 171 or the gear cover 172 are quickly discharged. be able to.
Further, by providing the drainage groove 168 in the bracket portion 171, the shape of the gear cover 172 is changed, or the position of the bolt insertion hole 172 b for fixing to the casing described later is changed. Even if there is a change, the drain part 185 can be easily configured by sharing the bracket part 171.

As shown in FIGS. 1, 2, and 4, the gear cover 172 opens to the side facing the bracket portion 171, and includes the clutch mechanism 5, the transmission pinion gear (transmission gear) 70, and an idle gear 101 described later. A housing recess 173 for housing is formed.
The housing recess 173 includes a pinion gear housing recess 173a in which the transmission pinion gear 70 is housed and an idle gear housing recess 173b in which the idle gear 101 is housed, and is formed so that the housing recesses 173a and 173b communicate with each other. Has been.

Further, in the receiving recess 173, an opening portion 173c that fits in one opening portion 171a of the bracket portion 171 when the gear cover 172 and the bracket portion 171 are overlapped with each other is provided at the periphery of the opening portion of the pinion gear receiving recess portion 173a. Projected.
The inlay portion 173c is formed in a substantially C shape in which the idle gear housing recess 173b side is opened in plan view as viewed from the axial direction so as to correspond to the shape of the peripheral edge of the opening of the pinion gear housing recess 173a.

Here, the positioning pin 184 that is press-fitted and fixed to the contact surface 172s of the gear cover 172 is disposed in the vicinity of a position on the opposite side of the pinion gear housing recess 173a on the periphery of the opening of the idle gear housing recess 173b. It is in the state. In other words, the positioning pin 184 is located on the opposite side of the inlay portion 173c with the idle gear 101 (an idle shaft 102 described later) interposed therebetween. In other words, the inlay portion 173c and the positioning pin 184 are arranged as far as possible from each other on the contact surface 172s of the gear cover 172.
Thus, the substantially C-shaped inlay portion 173c and the opening 171a, the positioning pin 184, and the pin insertion hole 166 can be used for positioning with a simple structure.

In addition, a bottomed bearing recess 47 is formed coaxially with the drive shaft 4 at the bottom 173 d of the housing recess 173. Furthermore, a shaft through hole 179 through which an idle shaft 102 described later passes is formed in the bottom 173d of the housing recess 173 on the side of the bearing recess 47.
The bearing recess 47 has an inner diameter larger than the outer diameter of the drive shaft 4. A sliding bearing 178 for rotatably supporting one side end (left side end in FIG. 1) of the drive shaft 4 is press-fitted and fixed to the bearing recess 47. The sliding bearing 178 is impregnated with a lubricating oil made of a desired base oil so that the drive shaft 4 can be brought into sliding contact smoothly.

A load receiving member 50 is disposed between the bottom of the bearing recess 47 and the one end face 4 c of the drive shaft 4.
The load receiving member 50 is a flat metal member, and for example, a ring-shaped washer formed by pressing is employed. The load receiving member 50 is made of a material having higher hardness than the drive shaft 4 and excellent wear resistance. As a material of the load receiving member 50, for example, carbon tool steel such as SK85 is suitable.

  By disposing the load receiving member 50, even when a thrust load is generated on the drive shaft 4 toward one side (left side in FIG. 1), the movement of the drive shaft 4 is restricted by the load receiving member 50 provided on the gear cover 172. However, the thrust load of the drive shaft 4 can be received. Further, since the one end surface 4c of the drive shaft 4 and the load receiving member 50 are in sliding contact with each other when the drive shaft 4 is rotated, it is possible to prevent the one end surface 4c of the drive shaft 4 and the gear cover 172 from being in direct contact. Therefore, wear of the gear cover 172 can be prevented and the starter 1 having excellent durability can be obtained.

  In addition, grease for reducing friction at the time of sliding contact with the one end surface 4c of the drive shaft 4 is applied around the load receiving member 50, and the grease impregnated in the sliding bearing 178 is lubricated. Since oil containing the same type of base oil as that of oil is used, the lubricating oil of the sliding bearing 178 can be held for a long period of time.

  A recess 4a is formed at the other end 4d of the drive shaft 4 so that the one end (the left end in FIG. 1) of the rotating shaft 52 can be inserted and fitted therein. A slide bearing 4b is press-fitted into the inner peripheral surface of the recess 4a, and the drive shaft 4 and the rotary shaft 52 are connected so as to be relatively rotatable.

  An oil seal 190 and a ball bearing 180 are provided in the shaft through-hole 179 of the gear cover 172 in order from the one end surface 172r side opposite to the contact surface 172s. The oil seal 190 is for preventing dust and water from entering the gear cover 172 from the outside through the shaft through hole 179. The ball bearing 180 is for rotatably supporting an idle shaft 102 described later.

  Furthermore, an inner cylindrical portion 186 and an outer cylindrical portion 187 are provided on the one end surface 172r of the gear cover 172 so as to surround the shaft through hole 179 and project on a concentric circle. The inner cylindrical portion 186 and the outer cylindrical portion 187 also have a role to prevent dust and water from entering the gear cover 172 from the outside through the shaft through hole 179.

  In addition, the gear cover 172 is integrally formed with a pair of mounting bracket portions 172t formed on both sides of the housing recess 173 so as to project outward from the contact surface 172s. The mounting bracket portion 172t is formed to be tapered as it is separated from the housing recess 173, and a bolt insertion hole 172b is formed at each apex portion thereof. By inserting a bolt (not shown) into the bolt insertion hole 172b, the gear cover 172 can be fixed to a housing (engine, vehicle chassis, etc.) not shown.

(Clutch mechanism)
As shown in FIG. 1, a helical spline 19 is formed substantially at the center in the axial direction of the drive shaft 4. The clutch mechanism 5 is helically engaged with the helical spline 19.
The clutch mechanism 5 includes a substantially cylindrical clutch outer 18, a clutch inner 22 formed coaxially with the clutch outer 18, and a clutch cover 6 that integrally fixes the clutch outer 18 and the clutch inner 22. ing.

  The clutch mechanism 5 is provided with a so-called known one-way clutch function in which the rotational force from the clutch outer 18 side transmits power to the clutch inner 22, but the rotational force from the clutch inner 22 side is not transmitted to the clutch outer 18. ing. As a result, when the engine is started, when the engine is in an overrun state in which the rotational speed of the clutch inner 22 is faster than that of the clutch outer 18, the rotational force from the ring gear 23 side of the engine is cut off. The clutch mechanism 5 transmits the rotational force to each other when the torque difference generated between the clutch outer 18 and the clutch inner 22 and the rotational speed difference are within predetermined values. On the other hand, when the torque difference and the rotational speed difference exceed predetermined values, the transmission of the rotational force is interrupted. That is, the clutch mechanism 5 also has a so-called torque limiter function.

A sleeve 18a having a reduced diameter is integrally formed on the other side (right side in FIG. 1) of the clutch outer 18, and a helical spline 18b that meshes with the helical spline 19 of the drive shaft 4 is formed on the inner peripheral surface thereof. Yes. Accordingly, the clutch mechanism 5 is provided so as to be slidable in the axial direction with respect to the drive shaft 4.
A step portion 18 c is formed on one of the sleeves 18 a on the inner peripheral surface of the clutch outer 18. The inner peripheral surface of the stepped portion 18c is formed with a larger diameter than the inner peripheral surface of the sleeve 18a.
A clutch cover 6 described later is fixed to the outer peripheral surface of the clutch outer 18 by, for example, caulking.

The clutch inner 22 has a diameter larger than that of the sleeve 18 a of the clutch outer 18, and a space is formed between the inner peripheral surfaces of the clutch inner 22 and the stepped portion 18 c and the drive shaft 4. A return spring 21 described later is disposed in this space.
A substantially disc-shaped clutch washer 64 is externally fitted and fixed to the outer peripheral surface of the clutch inner 22 at a position corresponding to the one end surface of the clutch outer 18 in the radial direction.

The clutch cover 6 is a bottomed cylindrical member having a main body cylinder portion 68 and a bottom wall 66 of one of the main body cylinder portions 68 (left side in FIG. 1), and for example, a metal plate material such as iron is drawn. It is formed by.
The main body cylinder portion 68 is externally inserted into the clutch outer 18 and the clutch washer 64, and is fixed to the clutch outer 18 and the clutch washer 64 by crimping the other edge portion of the main body cylinder portion 68 to the other end surface of the clutch outer 18. Is done.
An opening penetrating one and the other is formed in the approximate center of the bottom wall 66, and a reinforcing cylinder portion 67 extending from the opening toward one side in the axial direction is formed. The reinforcing cylinder portion 67 is formed concentrically with the drive shaft 4, and the drive shaft 4 is inserted therethrough.

The drive shaft 4 is provided with a movement restricting portion 20 on one side (left side in FIG. 1) of the helical spline 19.
The movement restricting portion 20 is a substantially ring-shaped member that is externally fitted to the drive shaft 4. The movement restricting portion 20 is provided in a state in which movement in one axial direction is restricted by the circlip 20 a, and a step formed in the clutch outer 18. The diameter of the step portion 18c is larger than that of the inner peripheral surface so as to be able to interfere with the portion 18c. As will be described later, when the clutch mechanism 5 slides to one side, the step portion 18c of the clutch outer 18 and the movement restricting portion 20 interfere with each other. Thereby, the sliding movement amount to one side of the clutch mechanism 5 is regulated.

  A return spring 21 is provided between the movement restricting portion 20 and the sleeve 18 a of the clutch outer 18 and between the inner peripheral surface of the step portion 18 c and the outer peripheral surface of the drive shaft 4. The return spring 21 is formed so as to surround the drive shaft 4 and is provided in a compressed and deformed state. As a result, the clutch outer 18 is constantly biased so as to be pushed back toward the motor unit 3 side.

The clutch mechanism 5 thus formed is integrally provided with a transmission pinion gear 70 at the tip of the clutch inner 22.
The transmission pinion gear 70 is formed of a cylindrical portion 70a that is slidably fitted to the drive shaft 4 and an external gear portion 70b that is integrally formed on the outer peripheral surface and meshed with an idle gear 101 described later. . And the cylinder part 70a and the clutch inner 22 are integrally molded.

  An outer flange portion 73 is integrally formed on the clutch mechanism 5 side, which is the base end side of the cylindrical portion 70a, with an axial distance from the outer gear portion 70b of the transmission pinion gear 70. Two sliding bearings 72 and 72 for slidably supporting the transmission pinion gear 70 on the drive shaft 4 are provided on both axial sides of the inner peripheral surface of the cylindrical portion 70a.

(Idle gear unit)
FIG. 8 is an enlarged cross-sectional view of the idle gear unit. 1 and 8, the starter 1 is in a stationary state (a state in which the idle shaft 102 is retracted) below the center axis of the idle shaft 102, and the starter 1 is in an energized state (the idle shaft 102 moves forward). , A state in which a drive pinion gear (drive gear) 110 and a ring gear 23 of an engine (not shown) are engaged with each other.

  As shown in FIGS. 1 and 8, the idle gear unit 100 includes an idle shaft 102 disposed in parallel with the drive shaft 4, and an idle gear that is integrally formed with an intermediate portion in the axial direction of the idle shaft 102 and meshes with the transmission pinion gear 70. 101 and a drive pinion gear 110 that is provided at one end 102 a of the idle shaft 102 and can mesh with the ring gear 23.

The idle gear 101 is formed so as to expand from the idle shaft 102 to the outer peripheral side, and an outer gear portion 101b is formed on the outer peripheral surface thereof.
Here, the reduction ratio between the external gear portion 101 b of the idle gear 101 and the external gear portion 70 b of the transmission pinion gear 70 is set so that the rotational speed of the idle gear 101 decreases with respect to the rotational speed of the transmission pinion gear 70. Yes. Thereby, the rotational torque of the idle shaft 102 can be made larger than the rotational torque of the drive shaft 4. Thus, by adjusting the gear ratio between the transmission pinion gear 70 and the idle gear 101, a torque-oriented type or rotation-oriented type starter can be obtained.

  Further, the idle gear 101 and the transmission pinion gear 70 are constituted by helical gears (helical gears). The tooth twist direction of the idle gear 101 is set to the same direction as the tooth twist direction of the drive pinion gear 110 described later. On the other hand, the twist direction of the teeth of the transmission pinion gear 70 is set to the same direction as the twist direction of the teeth of the ring gear 23.

One end portion 102 a (the left end portion 102 a in FIGS. 1 and 8) of the idle shaft 102 passes through the shaft through hole 179 of the gear cover 172 and protrudes outward from the gear cover 172. That is, the front side of one end portion 102 a of the idle shaft 102 is rotatably supported by the ball bearing 180 provided on the gear cover 172.
The idle shaft 102 is supported by a shaft hole 174 having the other end 102b formed in the bracket portion 171 so as to be rotatable and slidable in the axial direction (thrust direction) via the slide bearing 103. Yes.

  Here, the gap K1 formed between the other end portion 102b of the idle shaft 102 and the shaft hole 174 of the bracket portion 171 serves as a lubricant for enhancing the slidability of the idle shaft 102 with respect to the slide bearing 103. The grease is filled. On the other hand, a grease reservoir 99 is recessed at the other end 102 b of the idle shaft 102.

  The grease reservoir 99 prevents the grease from flowing out from the gap K1 due to the pumping action when the other end 102b of the idle shaft 102 is inserted into the slide bearing 103 of the bracket 171. That is, when the volume of the gap K1 is changed by the sliding movement of the idle shaft 102 (when the volume of the gap K1 is changed to be small), the grease in the gap K1 is received by the grease reservoir 99. Thereby, it is possible to prevent grease from being scattered outside the bracket portion 171.

  The grease reservoir 99 is tapered so that the opening area gradually increases toward the end 102b. For this reason, for example, when the volume of the gap portion K1 changes so as to increase, the grease once accumulated in the grease pool portion 99 tends to flow out into the gap portion K1. Therefore, the slidability between the sliding bearing 103 and the idle shaft 102 is sufficiently ensured by the circulation of the grease between the gap K1 and the grease reservoir 99.

  Further, a disc-shaped idle washer 104 is externally fitted to the outer peripheral portion of the idle shaft 102 on the clutch mechanism 5 side with respect to the idle gear 101. Movement of the idle washer 104 in the direction of disengagement toward the clutch mechanism 5 is restricted by a retaining ring 105 attached to the idle shaft 102. Further, the outer diameter of the idle washer 104 is set to be substantially the same as the outer diameter of the external gear portion 101b. Further, the outer periphery of the idle washer 104 is inserted into an annular gap between the external gear portion 70 b of the transmission pinion gear 70 and the outer flange portion 73.

As a result, the idle shaft 102 having the idle gear 101 can move in the axial direction along with the transmission pinion gear 70 via the idle washer 104.
The idle washer 104 has a role for improving the slidability between the transmission pinion gear 70 and the idle gear 101. For this reason, the idle washer 104 is also coated with grease or the like as a lubricant.

  Further, in the idle shaft 102, a stepped portion 102d is formed on the idle gear 101 side of the portion inserted through the ball bearing 180 by increasing the outer diameter. When the stepped portion 102d hits the ball bearing 180, the amount of movement of the idle shaft 102 toward the drive pinion gear 110 is restricted.

  Further, a spline 108 is formed on the outer peripheral surface of one end portion 102 a of the idle shaft 102. The drive pinion gear 110 provided at one end 102a of the idle shaft 102 is formed with a spline 110a that can be spline-fitted to the spline 108 on the distal end side of the inner peripheral surface. The length of the spline 108 on the idle shaft 102 side is set to be longer in the axial direction than the length of the spline 110a of the drive pinion gear 110. As a result, the idle shaft 102 and the drive pinion gear 110 are provided in a state in which they cannot rotate relative to each other and are slidable in the axial direction.

The idle shaft 102 is formed with a stepped portion 102c having a diameter larger than that of the spline 108 side on the other side (right side in FIGS. 1 and 8) of the spline 108.
On the other hand, an extension cylinder portion 110d extends from the other end face (right side in FIGS. 1 and 8) of the drive pinion gear 110.

  The extension cylinder portion 110 d is formed concentrically with the idle shaft 102. The extension cylinder part 110d can come into contact with the step part 102c when the drive pinion gear 110 slides to the other axial direction (the right side in FIGS. 1 and 8). That is, when the drive pinion gear 110 slides in the axial direction with respect to the idle shaft 102, the extension cylinder portion 110d abuts against the step portion 102c, thereby restricting the movement of the drive pinion gear 110 to the other.

  A retaining ring 106 that is externally fitted and fixed to the idle shaft 102 is provided at one end 102 a of the idle shaft 102. As a result, the drive pinion gear 110 is restricted from slipping out of the idle shaft 102 to one side of the idle shaft 102.

Here, in the drive pinion gear 110, the pitch diameter D1 of the external gear portion 110g is smaller than the pitch diameter D2 of the external gear portion 101b of the idle gear 101.
It is preferable to set so as to satisfy D1 ≦ D2.
Moreover,
D1 <D2
It is preferable to set so as to satisfy the above.

  When the pitch diameter D2 of the external gear portion 101b of the idle gear 101 is larger than the pitch diameter D1 of the external gear portion 110g, the torque obtained by the external gear portion 101b becomes larger than the torque output from the drive pinion gear 110. That is, torque transmission from the idle gear 101 side, that is, the drive shaft 4 side to the drive pinion gear 110 can be performed efficiently.

  The ring gear 23 and the drive pinion gear 110 are helical gears, and the torsional direction of the teeth of the ring gear 23 and the drive pinion gear 110 is such that the drive pinion gear 110 drives the ring gear 23 with respect to the ring gear 23. Is set to generate a thrust load in the jumping direction.

Further, when cranking at the time of starting the engine, the rotational speed of the ring gear 23 is likely to vary. Here, when a rotational speed difference occurs between the helically meshed drive pinion gear 110 and the ring gear 23, the direction of the thrust load applied to the drive pinion gear 110 changes.
When the rotational speed of the ring gear 23 is lower than the rotational speed of the drive pinion gear 110, a thrust load is generated in the drive pinion gear 110 in a direction approaching the ring gear 23. When the rotational speed of the ring gear 23 is higher than the rotational speed of the drive pinion gear 110, a thrust load is generated in the drive pinion gear 110 in a direction away from the ring gear 23 (rightward in FIG. 1).

  However, in this case, since the rotational speed of the idle gear 101 is faster than the rotational speed of the transmission pinion gear 70, the thrust in the direction opposite to the thrust load acting on the idle gear 101 from the transmission pinion gear 70 and the driving pinion gear 110 from the ring gear 23. A load acts. For this reason, the thrust load acting on the drive pinion gear 110 in the direction away from the ring gear 23 is offset.

That is, the twist direction of the teeth of the idle gear 101 is set to the same direction as the twist direction of the teeth of the drive pinion gear 110, while the twist direction of the teeth of the transmission pinion gear 70 is the same direction as the twist direction of the teeth of the ring gear 23. Therefore, the direction of the thrust load generated in the drive pinion gear 110 and the direction of the thrust load generated in the idle gear 101 are reversed, so that the thrust loads of both are offset.
At this time, it is preferable to set the thrust load in the direction in which the drive pinion gear 110 is separated to be larger than the thrust load in the opposite direction acting on the idle gear 101. Further, the thrust load in the direction in which the drive pinion gear 110 is separated is preferably smaller than the attractive force by the electromagnetic device 9.

On the inner peripheral surface of the drive pinion gear 110, a diameter-increased portion 111 is formed on the rear end side of the spline 110a via a stepped portion 110b. The enlarged portion 111 is accommodated between the idle shaft 102 and the drive pinion gear 110. A portion 112 is formed.
In the storage portion 112, the opening formed on the idle gear 101 side is closed by a stepped portion 102 e provided on the spline 108 of the idle shaft 102 on the end portion on the idle gear 101 side. ing.

  In the storage portion 112, a pinion spring 113 formed so as to surround the outer peripheral surface of the idle shaft 102 is stored. The pinion spring 113 is made of a coil spring, for example.

The pinion spring 113 is compressed and deformed by the stepped portion 110 b of the enlarged diameter portion 111 of the drive pinion gear 110 and the stepped portion 102 e of the idle shaft 102 while being housed in the housing portion 112. As a result, the drive pinion gear 110 is biased toward the ring gear 23 with respect to the idle shaft 102.
Further, as will be described later, the pinion spring 113 functions as a so-called damper mechanism that absorbs an impact by elastically deforming in the axial direction when the drive pinion gear 110 and the ring gear 23 come into contact with each other. Thereby, the wear of the drive pinion gear 110 and the ring gear 23 is suppressed, and the durability of the starter 1 is improved.

(Electromagnetic device)
As shown in FIG. 1, a yoke 25 constituting the electromagnetic device 9 is fitted and fixed to the inner peripheral surface of the housing 17 (bracket portion 171) closer to the motor portion 3 than the clutch mechanism 5. The yoke 25 is formed in a bottomed cylindrical shape made of a magnetic material, and a large part of the center in the radial direction of the bottom portion 25a is greatly opened.

  Further, an annular plunger holder 26 made of a magnetic material is provided on the end of the yoke 25 opposite to the bottom 25a. The plunger holder 26 is integrally formed with an annular holder body 26a and a plunger holder-side cylindrical portion 26b that is bent and extended from the radially inner side of the holder body 26a toward the other side in the axial direction. As a result, the distance between the later-described gear plunger 80 and the iron core 88 is reduced, so that the suction force of the iron core 88 by the plunger holder 26 (hereinafter sometimes simply referred to as “suction force”) can be increased.

An exciting coil 24 formed in a substantially cylindrical shape is housed in a housing recess 25 b formed radially inward by the yoke 25 and the plunger holder 26. That is, the holder body 26 a of the plunger holder 26 is formed so as to cover one side surface of the excitation coil 24, and the plunger holder-side cylindrical portion 26 b is bent and extended so as to face the radially inner side of the excitation coil 24. ing.
The exciting coil 24 is electrically connected to an ignition switch (not shown) via a connector 150 provided on the outer peripheral surface of the bracket portion 171.

A plunger mechanism 37 is provided in the gap between the inner peripheral surface of the excitation coil 24 and the outer peripheral surface of the drive shaft 4 so as to be slidable in the axial direction with respect to the excitation coil 24.
The plunger mechanism 37 includes a substantially cylindrical switch plunger 27 formed of a magnetic material, and a gear plunger 80 disposed in a gap between the switch plunger 27 and the outer peripheral surface of the drive shaft 4. .

9 is a perspective view of the switch plunger, FIG. 10 is a sectional view of the switch plunger, and FIG. 11 is an enlarged view of a portion A in FIG.
As shown in FIGS. 9 to 11, the switch plunger 27 is formed by pressing a metal plate made of a magnetic material. The switch plunger 27 is integrally formed with a switch plunger side cylindrical portion 121 provided so as to close a radially inner side of the housing recess 25 b formed by the yoke 25 and the plunger holder 26. One opening portion (the left opening portion in FIG. 10 and the opening portion on the clutch mechanism 5 side) 122 of the switch plunger side cylindrical portion 121 is an enlarged diameter portion 122a that is enlarged by a step. The enlarged diameter portion 122a functions as an escape portion for effectively suppressing the magnetic flux generated in the plunger holder 26 from leaking directly from the plunger holder side cylindrical portion 26b to the switch plunger 27 side (details). Will be described later).

  Note that the inner diameter of the enlarged diameter portion 122a is set to such a size that a switch return spring 27a, which will be described later, can reliably press the end portion on the one opening 122 side of the switch plunger side cylindrical portion 121. That is, if the inner diameter of the enlarged diameter portion 122a is made too large, the thickness of one opening 122 of the switch plunger side cylindrical portion 121 becomes too thin, and the switch return spring 27a becomes the switch plunger side cylindrical portion 121. Thus, the end on the one opening 122 side cannot be reliably pressed.

Further, on the inner peripheral surface of the switch plunger side cylindrical portion 121, a ridge 122b is formed over the entire circumference on the other side of the enlarged diameter portion 122a (the right side in FIG. 10, the motor portion 3 side). The diameter-expanded portion 122 a and the protruding portion 122 b are continuously formed on the inner peripheral surface of the switch plunger side cylindrical portion 121 from the one opening 122 side.
As a method of forming the enlarged diameter portion 122a and the protruding portion 122b, for example, after a jig is mounted on the inner peripheral surface of the switch plunger side cylindrical portion 121, the diameter is slightly larger than the inner diameter of the switch plunger side cylindrical portion 121. There is a method in which a large columnar jig is abutted from one opening 122 side of the switch plunger side cylindrical portion 121. Thereby, the diameter expansion part 122a is formed, and the remaining thickness of the switch plunger side cylindrical part 121 by having formed the diameter expansion part 122a can be made into the protruding item | line part 122b.

  An outer flange portion 29 projecting to the outer peripheral side is integrally formed with the other opening portion (the opening portion on the right side in FIG. 10, the opening portion on the motor portion 3 side) 123 of the switch plunger side cylindrical portion 121. Further, a shaft holder 29 a is formed to extend on one side of the outer flange portion 29. The shaft holder 29a is for holding a switch shaft 30 to be described later, and is formed in a U shape so as to receive an end of the switch shaft 30.

A ring member 27r is integrally provided on the inner peripheral surface of the switch plunger side cylindrical portion 121. The ring member 27r is for initially pressing the gear plunger 80 toward the ring gear 23 side when the switch plunger 27 moves toward one side (ring gear 23 side). The gear plunger 80 is provided so as to come into contact with and separate from the ring member 27r.
Further, a switch return spring 27a made of a leaf spring material that urges the switch plunger side cylindrical portion 121 on one opening 122 side and the plunger holder 26 in a direction away from each other is provided. .

  Returning to FIG. 1, the gear plunger 80 is provided on the radially inner side of the switch plunger side cylindrical portion 121 and concentrically with the switch plunger side cylindrical portion 121. The gear plunger 80 includes a plunger inner 81 disposed on the radially inner side, a plunger outer 85 disposed on the radially outer side, and a plunger spring 91 disposed between the plunger inner 81 and the plunger outer 85. ing.

  The plunger inner 81 is formed in a substantially cylindrical shape with resin or the like. The inner diameter of the plunger inner 81 is formed to be slightly larger than the outer diameter of the drive shaft 4 so that it can be inserted into the drive shaft 4. Thereby, the plunger inner 81 is provided so as to be slidable in the axial direction with respect to the drive shaft 4.

An outer flange portion 82 protruding outward in the radial direction is integrally formed at one end 81a (the left end in FIG. 1) of the plunger inner 81. As will be described later, when the plunger inner 81 slides in one direction, one end 81a of the plunger inner 81 comes into contact with the other end of the clutch outer 18, and the clutch mechanism 5 and the transmission pinion gear 70 slide in one direction. I am letting.
Plural claw portions 83 whose outer diameter gradually increases from the other side toward one side are provided at the other end 81b (right end in FIG. 1) of the plunger inner 81 in the circumferential direction. Further, a groove portion 84 is formed along the circumferential direction on one of the claw portions 83 (left side in FIG. 1).

The plunger outer 85 is formed in a substantially cylindrical shape with resin or the like, like the plunger inner 81. The inner diameter of the plunger outer 85 is formed to be slightly larger than the outer diameter of the outer flange portion 82 of the plunger inner 81, and is inserted into the plunger inner 81.
An inner flange portion 86 projecting radially inward is integrally formed at the other end 85a of the plunger outer 85 (the right end in FIG. 1). The inner flange portion 86 is formed so that the inner diameter is smaller than the outer diameter of the claw portion 83 of the plunger inner 81 and larger than the outer diameter of the bottom portion of the groove portion 84 of the plunger inner 81. Then, by arranging the inner flange portion 86 of the plunger outer 85 in the groove portion 84 of the plunger inner 81, the plunger inner 81 and the plunger outer 85 are integrated, and the plunger mechanism 37 is configured.

  The wall thickness of the inner flange portion 86 of the plunger outer 85 is formed thinner than the width of the groove portion 84 of the plunger inner 81. Thereby, a clearance is formed between the inner flange portion 86 of the plunger outer 85 and the groove portion 84 of the plunger inner 81. Therefore, the plunger inner 81 and the plunger outer 85 are relatively slidable in the axial direction by the clearance between the inner flange portion 86 of the plunger outer 85 and the groove portion 84 of the plunger inner 81.

An outer flange portion 87 protruding outward in the radial direction is integrally formed at the other end 85a (the right end in FIG. 1) of the plunger outer 85. The outer flange portion 87 functions as a contact portion that contacts the ring member 27r of the switch plunger 27.
A ring-shaped iron core 88 is provided on the outer peripheral surface of the plunger outer 85 on one of the outer flange portions 87 (left side in FIG. 1). The iron core 88 is integrally formed with the plunger outer 85 by, for example, a resin mold. As will be described later, the iron core 88 is attracted to the electromagnetic device 9 with a predetermined attraction force by a magnetic flux generated when a current is supplied to the exciting coil 24.

A storage portion 90 is formed between the outer flange portion 82 of the plunger inner 81 and the inner flange portion 86 of the plunger outer 85. A plunger spring 91 formed so as to surround the outer peripheral surface of the plunger inner 81 is accommodated in the accommodating portion 90.
The plunger spring 91 is compressed and deformed by the outer flange portion 82 of the plunger inner 81 and the inner flange portion 86 of the plunger outer 85 while being accommodated in the accommodating portion 90. The plunger inner 81 is biased toward one side (left side in FIG. 1) and the plunger outer 85 is biased toward the other side (right side in FIG. 1).

  Here, since the one end 81a of the plunger inner 81 and the other end of the clutch outer 18 are not in contact with each other, the clutch outer 18 is pressed against the stopper 94 by the spring load of the return spring 21. ing. Thus, when the starter 1 is stationary, the clutch mechanism 5 is not pushed out by the spring load of the plunger spring 91, that is, the transmission pinion gear 70 is not pushed out carelessly.

  On the other hand, in the energized state of the starter 1, when the gear plunger 80 is displaced to the maximum (left side in FIG. 1), the one end 81a of the plunger inner 81 is always in contact with the other end of the clutch outer 18 of the clutch mechanism 5. It will be in contact. That is, the plunger spring 91 functions as a backlash absorbing mechanism that prevents the occurrence of an axial gap between the clutch mechanism 5 and the gear plunger 80 and absorbs the backlash of the clutch mechanism 5.

  A switch shaft 30 is erected on the shaft holder 29a of the switch plunger 27 along the axial direction via the holder member 30a. The switch shaft 30 passes through the top plate 12 of the motor unit 3 and a brush holder 33 described later. A movable contact plate 8 of the switch unit 7 disposed adjacent to the commutator 61 of the brushed DC motor 51 is connected to the end of the switch shaft 30 protruding from the top plate 12.

  The movable contact plate 8 is attached to the switch shaft 30 so as to be slidable along the axial direction, and is floatingly supported by the switch spring 32. The movable contact plate 8 can be moved toward and away from the fixed contact plate 34 of the switch unit 7 fixed to a brush holder 33 described later.

  The fixed contact plate 34 includes a first fixed contact plate 34 a disposed on the radially inner side on the commutator 61 side with the switch shaft 30 interposed therebetween, and a second fixed disposed on the radially outer side opposite to the commutator 61. It is divided into contact plates 34b. The movable contact plate 8 is in contact with the first fixed contact plate 34a and the second fixed contact plate 34b. The movable contact plate 8 strokes along the drive shaft 4 and comes into contact with the first fixed contact plate 34a and the second fixed contact plate 34b, so that the first fixed contact plate 34a and the second fixed contact plate 34b are turned on. Become electrically connected.

Here, the clutch outer 18 of the clutch mechanism 5 is biased toward the plunger inner 81 by the return spring 21. Therefore, when the starter 1 is stationary, the clutch mechanism 5 presses the switch plunger 27 to the other side (the right side in FIG. 1) via the gear plunger 80 and the ring member 27r. Thereby, the movable contact plate 8 is pressed to the other side and is in an OFF state separated from the fixed contact plate 34.
On the other hand, when the electromagnetic device 9 slides the transmission pinion gear 70 and the movable contact plate 8 to one side (left side in FIG. 1), the movable contact plate 8 is turned on and the transmission pinion gear 70 contacts the ring gear 23.

  A brush holder 33 is provided on the other side (right side in FIG. 1) of the electromagnetic device 9 and the planetary gear mechanism 2. Here, on the outer peripheral side of the second fixed contact plate 34b, a cut and raised portion 34c that is integrally formed by bending in the axial direction is provided, and the shaft terminal 44a is inserted through the insertion hole of the cut and raised portion 34c. Are provided so as to penetrate the outer wall 33a of the brush holder 33 and protrude radially outward of the starter 1. Furthermore, a terminal nut 44b to which the anode of the battery is electrically connected is provided at the tip of the protruding side of the shaft terminal 44a.

  The brush holder 33 is provided with a cover 45 for protecting the fixed contact plate 34 and the periphery of the switch shaft 30. The brush holder 33 and the cover 45 are fixed while being sandwiched between the motor yoke 53 and the bracket portion 171.

  In the brush holder 33, four brushes 41 are arranged around the commutator 61 so as to be able to advance and retract along the radial direction. A brush spring 42 is provided on the base end side of each brush 41. Each brush 41 is urged toward the commutator 61 by the brush spring 42, and the tip of each brush 41 comes into sliding contact with the segment 62 of the commutator 61.

The four brushes 41 are constituted by two anode side brushes and two cathode side brushes, and two of these anode side brushes are first fixed contacts of the fixed contact plate 34 via a pigtail (not shown). It is connected to the plate 34a. On the other hand, the anode of a battery (not shown) is electrically connected to the second fixed contact plate 34b of the fixed contact plate 34 via a terminal nut 44b.
That is, when the movable contact plate 8 comes into contact with the fixed contact plate 34, voltage is applied to two anode-side brushes of the four brushes 41 via the terminal nut 44b, the fixed contact plate 34, and a pigtail (not shown). Is applied, and a current is supplied to the coil 59.

  Of the four brushes 41, two cathode-side brushes are connected to a ring-shaped center plate via a pigtail (not shown). Then, two cathode-side brushes among the four brushes 41 are electrically connected to the cathode of the battery via the center plate, the housing 17 and the vehicle body (not shown).

(Starter assembly method)
Next, a method for assembling the starter 1 will be described with reference to FIG.
FIG. 12 is an explanatory diagram showing the procedure for assembling the starter, and (a) to (d) show each step.

First, as shown in FIG. 12A, the electromagnetic device 9 is assembled in advance to the bracket portion 171 (electromagnetic device assembling step), and the motor is attached to the bracket portion 171 in a state where the electromagnetic device 9 is incorporated in the bracket portion 171. The part 3 is assembled and set as a subunit.
Here, the inner wall of the bracket portion 171 is provided with a reduced diameter portion 171d which is formed with a reduced diameter by a step closer to the one opening 171a than the electromagnetic device 9 (stopper 94). The reduced diameter portion 171d restricts the electromagnetic device 9 from coming out of the one opening 171a on the gear cover 172 side of the bracket portion 171, so that the electromagnetic device 9 does not come out of the bracket portion 171. can do.

Further, one end of the drive shaft 4 to which the clutch mechanism 5 is assembled is inserted into the sliding bearing 178 provided in the bearing recess 47 of the gear cover 172. Further, one end of the idle shaft 102 is inserted into the ball bearing 180 provided in the shaft through hole 179 of the gear cover 172 (preliminary assembly process). At this time, the meshing operation between the transmission pinion gear 70 and the idle gear 101 can be easily performed with good visibility.
Then, the drive pinion gear 110 is assembled to one end portion 102 a of the idle shaft 102. As a result, the drive shaft 4 and the idle shaft 102 are in a state where one side ends are supported by the gear cover 172.

In this state, the bracket portion 171 is moved toward the gear cover 172 so that the contact surface 171e of the bracket portion 171 and the contact surface 172s of the gear cover 172, which are sub-units of the electromagnetic device 9, the motor unit 3, and the gear cover 172 are overlapped. Move (see arrow in FIG. 12A).
At this time, as shown in FIG. 12B, first, the other end portion 102b of the idle shaft 102 is inserted into the slide bearing 103 provided in the shaft hole 174 of the bracket portion 171 (in FIG. 12B). (See part S1). At this time, the rotating shaft 52 of the motor unit 3 is not inserted into the recess 4a formed at the other end 4d of the drive shaft 4.

Further, when the bracket portion 171 and the gear cover 172 are moved toward each other, as shown in FIG. 12C, the other end of the drive shaft 4 is connected to the slide bearing 12a provided on the inner peripheral surface of the top plate 12. The side end 4d is inserted. Further, the positioning pin 184 of the gear cover 172 is inserted into the pin insertion hole 166 of the bracket portion 171 (see the portion S2 in FIG. 12C).
At this time, the positions of the bracket portion 171 and the gear cover 172 in the circumferential direction (the rotational direction of the drive shaft 4) are determined at two points (a point due to the sliding bearing 103 and the idle shaft 102, a point due to the pin insertion hole 166 and the positioning pin 184). It will be. For this reason, the relative position of the circumferential direction of the bracket part 171 and the gear cover 172 is determined.

  Here, the shaft diameter of the other end portion 102 b of the idle shaft 102 and the inner diameter of the slide bearing 103 of the bracket portion 171 cause some backlash (gap) between the other end portion 102 b and the slide bearing 103, respectively. It is set to a size of about. For this reason, even if a manufacturing error occurs in each of the pin insertion hole 166, the positioning pin 184, the shaft hole 174, etc., this manufacturing error is absorbed by the play between the other end 102b of the idle shaft 102 and the slide bearing 103. It can be done.

Further, when the positioning pin 184 of the gear cover 172 is inserted into the pin insertion hole 166 of the bracket portion 171, the other end portion 4 d of the drive shaft 4 is inserted into the slide bearing 12 a, but the carrier plate 16 is engaged. The hole 16b and the serration portion 4e of the drive shaft 4 are not engaged.
On the other hand, the axial length of the drive shaft 4 and the axial length of the rotary shaft 52 are determined so that the other side of the drive shaft 4 is inserted before the other end 102b of the idle shaft 102 is inserted into the slide bearing 103 of the bracket portion 171. The length is set such that the end 4d is not inserted into the sliding bearing 12a.

  Further, the fitting margin between the engagement hole 16b of the carrier plate 16 and the serration portion 4e of the other end 4d of the drive shaft 4 is such that the other end 102b of the idle shaft 102 is inserted into the shaft hole 174 of the bracket 171. It is set shorter than the generation. Also, the fitting allowance between the rotating shaft 52 and the drive shaft 4 is set shorter than the insertion allowance of the positioning pin 184 of the gear cover 172 with respect to the pin insertion hole 166 of the bracket portion 171.

Subsequently, when the bracket portion 171 and the gear cover 172 are further moved toward each other, as shown in FIG. 12 (d), the serration portion 4 e of the other side end portion 4 d of the drive shaft 4 is moved to the motor portion 3. The engagement holes 16b of the carrier plate 16 are engaged, and both engage with each other (see S3 in FIG. 12D).
Thus, the connection between the recess 4a of the drive shaft 4 that is difficult to visually recognize from the outside and the rotating shaft 52 of the motor unit 3 is performed after the relative position in the circumferential direction between the bracket unit 171 and the gear cover 172 is determined.

Also, almost simultaneously with the engagement of the serration portion 4e of the other end 4d of the drive shaft 4 and the engagement hole 16b of the carrier plate 16 of the motor portion 3, the one opening 171a of the bracket portion 171 is The spigot part 173c of the gear cover 172 is fitted with a spigot.
Subsequently, after the contact surface 171e of the bracket portion 171 and the contact surface 172s of the gear cover 172 are overlapped, both are fastened and fixed using bolts 177a and 177b (see FIG. 2) (bracket portion assembly step). Thereby, the assembly of the starter 1 is completed.

(Starter operation)
Next, the operation of the starter 1 will be described.
As shown in FIG. 1, when the starter 1 is in a stationary state before supplying current to the exciting coil 24, the clutch outer 18 biased by the return spring 21 is integrated with the transmission pinion gear 70. In a state where the inner 22 is pulled, it is fully urged toward the motor unit 3 side (the right side in FIG. 1). The clutch outer 18 of the clutch mechanism 5 stops at a position where it abuts against the stopper 94. Accordingly, the idle gear unit 100 having the idle gear 101 meshed with the transmission pinion gear 70 is disconnected with the drive pinion gear 110 and the ring gear 23 separated from each other.

  Further, the switch plunger 27 is pushed back by the switch return spring 27a, and is fully moved to the motor unit 3 side (the right side in FIG. 1). The outer flange 29 of the switch plunger 27 is stopped in contact with the top plate 12. Further, the movable contact plate 8 of the switch shaft 30 erected on the outer flange portion 29 is separated from the fixed contact plate 34 and is electrically disconnected.

When an ignition switch (not shown) of the vehicle is turned on from this state, a current is supplied to the exciting coil 24 to be excited, and a magnetic path through which the magnetic flux passes through the switch plunger 27 and the gear plunger 80 is formed. As a result, the switch plunger 27 and the gear plunger 80 slide and move toward the ring gear 23 side.
At this time, since the ring member 27r is integrally provided on the inner peripheral surface of the switch plunger 27, the ring member 27r presses the gear plunger 80, and the gear plunger 80 is initially directed toward the ring gear 23. By pressing, the switch plunger 27 and the gear plunger 80 are integrally slid and moved toward the ring gear 23 side.

  The clutch outer 18 is in helical spline engagement with the drive shaft 4, and the sleeve 18 a is in contact with the plunger inner 81 of the gear plunger 80. Therefore, when the switch plunger 27 and the gear plunger 80 slide to the ring gear 23 side, the clutch outer 18 is pushed out while slightly rotating relative to the drive shaft 4 by the inclination angle of the helical spline 18b. Further, the transmission pinion gear 70 and the idle gear unit 100 are also pushed toward the ring gear 23 side in conjunction with the sliding movement of the gear plunger 80 via the clutch mechanism 5.

  Further, when the switch plunger 27 moves to the ring gear 23 side, the movable contact plate 8 moves toward the fixed contact plate 34 side via the outer flange portion 29 and the switch shaft 30 and comes into contact with the fixed contact plate 34. Since the movable contact plate 8 is floatingly supported so as to be axially displaceable with respect to the switch shaft 30, the pressing force of the switch spring 32 is applied to the movable contact plate 8 and the fixed contact plate 34.

When the movable contact plate 8 comes into contact with the fixed contact plate 34, the voltage of a battery (not shown) is applied to two anode-side brushes of the four brushes 41, and the coil 59 is connected via the segment 62 of the commutator 61. Energized.
Then, a magnetic field is generated in the armature core 58, and a magnetic attractive force and a repulsive force are generated between the magnetic field and the permanent magnet 57 provided in the motor yoke 53. As a result, the armature 54 starts to rotate. When the armature 54 rotates, the rotational force of the rotating shaft 52 of the armature 54 (rotational force of the motor unit 3) is transmitted to the drive shaft 4 via the planetary gear mechanism 2, and the drive shaft 4 starts to rotate. .

  As the drive shaft 4 rotates, the clutch outer 18 that meshes with the helical spline 19 of the drive shaft 4 is rotated, and an inertial force acts on the clutch mechanism 5. Then, the clutch mechanism 5 is pushed toward the ring gear 23 side along the helical spline 19 by the inertial force. Here, since the force toward the ring gear 23 is acting on the gear plunger 28, the gear plunger 28 also moves toward the ring gear 23 as the clutch mechanism 5 moves.

  When the clutch mechanism 5 is pushed out toward the ring gear 23 side, the idle gear 101 is pushed out while rotating toward the ring gear 23 side in conjunction with the transmission pinion gear 70 integrated with the clutch mechanism 5. Then, the drive pinion gear 110 provided at the end 102 b of the idle shaft 102 is also pushed out while rotating to the ring gear 23 side integrally with the idle gear 101.

  When the drive pinion gear 110 starts to rotate, if the one end surface 110f of the drive pinion gear 110 and the other end surface 23a of the ring gear 23 are in contact with each other, the contact state is released and the gears mesh with each other. . Then, the driving pinion gear 110 is pushed toward the ring gear 23 by the urging force of the pinion spring 113, and the driving pinion gear 110 and the ring gear 23 start to mesh.

  At this time, the one end face 110f of the drive pinion gear 110 and the other end face 23a of the ring gear 23 are in contact with each other, or the axial dimensional distance between them is zero. For this reason, when the one end surface 110f of the drive pinion gear 110 and the other end surface 23a of the ring gear 23 are in contact with each other, when the drive pinion gear 110 is further pushed out, the pinion spring 113 contracts. As a result, the one end face 110 f of the drive pinion gear 110 is biased toward the other end face 23 a of the ring gear 23.

  That is, the pinion spring 113 constitutes a damper mechanism that absorbs a thrust load when the drive pinion gear 110 and the ring gear 23 come into contact with each other. Accordingly, even when the one end surface 110f of the drive pinion gear 110 and the other end surface 23a of the ring gear 23 are in contact with each other, the switch plunger 27 can be pushed out to a predetermined position and the drive pinion gear 110 can be pushed. The wear of the one end face 110f and the other end face 23a of the ring gear 23 can be suppressed, and the durability of the starter 1 can be improved.

  At this time, as described above, since the drive pinion gear 110 and the ring gear 23 are helically meshed, a thrust load in the direction of the ring gear 23 (the jumping direction) is generated in the drive pinion gear 110. The drive pinion gear 110 moves toward the ring gear 23 by the thrust load. Further, the clutch outer 18 is also pushed out toward the ring gear 23 against the urging force of the return spring 21 along the helical spline 19 by the inertial force.

At this time, a predetermined suction force toward the ring gear 23 is applied to the gear plunger 80. Therefore, the gear plunger 80 slides toward the ring gear 23 while pressing the clutch outer 18 so as to be interlocked with the sliding movement of the clutch outer 18. In this way, the drive pinion gear 110 is pushed out to the ring gear 23 side, and the ring gear 23 is engaged at a predetermined engagement position.
Thus, the ring gear 23 and the drive pinion gear 110 mesh with each other, and the rotational force of the drive shaft 4 is transmitted to the ring gear 23, whereby the engine is started.

FIG. 13 is an explanatory view showing a state when the switch plunger and the gear plunger are completely slid toward the ring gear side, and showing a state of generation of magnetic flux around the switch plunger and the gear plunger in this state. .
As shown in the figure, when the switch plunger 27 is completely slid toward the ring gear 23, the outer flange portion 29 of the switch plunger 27 is in contact with the bottom 25a of the yoke 25. Further, the iron core 88 of the gear plunger 80 comes into contact with the plunger holder side cylindrical portion 26b.

  In this state, a magnetic path composed of magnetic flux passing through the yoke 25, the switch plunger 27, the iron core of the gear plunger 80 and the plunger holder 26 is formed. Then, the iron core 88 of the gear plunger 80 is magnetically attracted to the protruding portion 122b formed on the plunger holder side cylindrical portion 26b and the switch plunger side cylindrical portion 121 and is held in place. Yes.

Here, since the enlarged diameter portion 122a is formed in the one opening portion 122 of the switch plunger side cylindrical portion 121, the interval between the enlarged diameter portion 122a and the plunger holder side cylindrical portion 26b becomes wide. Yes. For this reason, magnetic flux leakage from the plunger holder side cylindrical portion 26b directly to the switch plunger 27 can be effectively suppressed.
Moreover, the space | interval between the protruding item | line part 122b of the switch plunger 27 and the iron core 88 of the gear plunger 80 is narrow compared with the case where the protruding item | line part 122b is not formed. For this reason, the magnetic flux density between the protrusion 122b and the iron core 88 can be increased.
Therefore, the position of the iron core 88 of the gear plunger 80 can be reliably held by the plunger holder side cylindrical portion 26b and the convex portion 122b of the switch plunger 27.

  Here, since the drive pinion gear 110 and the ring gear 23 are helically meshed, when the rotational force of the drive shaft 4 is transmitted from the drive pinion gear 110 to the ring gear 23, the drive pinion gear 110 is directed toward one side (left side in FIG. 1). Thrust load is generated. The thrust load generated in the drive pinion gear 110 is transmitted to a retaining ring 106 provided on one side of the drive pinion gear 110, and then the idle shaft 102, the idle gear 101, the transmission pinion gear 70, the clutch inner 22, the clutch outer 18 and the movement restriction. It is transmitted to the drive shaft 4 via the part 20 and the circlip 20a. For this reason, a thrust load is generated on the drive shaft 4 toward one side, and the drive shaft 4 slides toward the other side.

  However, a load receiving member 50 is provided on the gear cover 172 of the housing 17. Thereby, as for the drive shaft 4, the one side end surface 4c contact | abuts to the load receiving member 50, and the slide movement to one side of the drive shaft 4 is controlled. Thus, the load receiving member 50 can effectively receive the thrust load applied to the drive shaft 4.

  On the other hand, after the meshing of the drive pinion gear 110 and the ring gear 23, the crank speed at the time of engine start varies during the cranking. Thereby, a thrust load is generated in the drive pinion gear 110 toward one side (left side in FIG. 1) and the other side (right side in FIG. 1).

Specifically, when the rotational speed of the ring gear 23 is slower than the rotational speed of the drive pinion gear 110, a thrust load is generated in the drive pinion gear 110 in the direction approaching the ring gear 23 (left side in FIG. 1).
On the other hand, when the rotational speed of the ring gear 23 is faster than the rotational speed of the drive pinion gear 110, a thrust load is generated in the drive pinion gear 110 in a direction away from the ring gear 23 (right side in FIG. 4).
In particular, in a vehicle having an idle stop function, the engine is frequently stopped / started, and the use frequency is higher than that of a general starter. Therefore, the thrust load as described above is frequently generated.

  However, when the rotational speed of the ring gear 23 is higher than the rotational speed of the drive pinion gear 110, a thrust load is generated in the drive pinion gear 110 in a direction away from the ring gear 23 (right side in FIG. 4). From the helical meshing part between the transmission pinion gear 70 and the transmission pinion gear 70, a thrust load in the direction opposite to the thrust load acting on the drive pinion gear 110 from the ring gear 23 acts.

That is, the twist direction of the teeth of the idle gear 101 is set to the same direction as the twist direction of the teeth of the drive pinion gear 110, while the twist direction of the teeth of the transmission pinion gear 70 is the same direction as the twist direction of the teeth of the ring gear 23. Is set to In such a state, the rotational speed of the idle gear 101 is higher than the rotational speed of the transmission pinion gear 70, whereas the rotational speed of the ring gear 23 is faster than the rotational speed of the drive pinion gear 110. For this reason, the thrust load acting on the drive pinion gear 110 in the direction away from the ring gear 23 can be offset.
Therefore, even if a thrust load is generated in the direction away from the ring gear 23 in the drive pinion gear 110, the helical engagement between the drive pinion gear 110 and the ring gear 23 is not released, and an appropriate and stable helical engagement state can be maintained.

In addition to this, the switch plunger side cylindrical portion 121 is formed with an enlarged diameter portion 122a at one opening portion 122 and a protruding strip portion 122b. For this reason, the position of the iron core 88 of the gear plunger 80 is reliably held by the plunger holder-side cylindrical portion 26 b and the convex portion 122 b of the switch plunger 27.
Therefore, for example, the inertia of the idle shaft 102 (idle gear 101) is increased by the thrust load applied to the drive pinion gear 110 in the direction away from the ring gear 23, and the thrust load cannot be offset by the idle gear 101 and the transmission pinion gear 70. Even if it exists, since the position of the gear plunger 80 is hold | maintained, the helical meshing of the drive pinion gear 110 and the ring gear 23 is not cancelled | released. For this reason, the appropriate stable helical meshing state can be maintained.

  In addition, the thrust load generated in the drive pinion gear 110 is transmitted to a retaining ring 106 provided on one side of the drive pinion gear 110, and then the bottom wall of the clutch cover 6 via the idle shaft 102, the clutch inner 22, and the clutch washer 64. 66. However, since the reinforcing cylinder portion 67 is integrally formed on the bottom wall 66, deformation of the clutch cover 6 in the axial direction is suppressed.

  When the engine is completely started and the rotational speed of the drive pinion gear 110 exceeds the rotational speed of the drive shaft 4, the one-way clutch function of the clutch mechanism 5 acts and the drive pinion gear 110 rotates idly. When the energization of the exciting coil 24 is stopped as the engine is started, the drive pinion gear 110 is detached from the ring gear 23 by the urging force of the return spring 21 against the clutch outer 18 and the movable contact plate 8 is fixed to the fixed contact plate 34. The brushed direct current motor 51 stops moving away from the motor.

(effect)
Thus, in the above-described embodiment, the housing 17 that houses the top plate 12 (the planetary gear mechanism 2), the electromagnetic device 9, the clutch mechanism 5, the idle gear unit 100, and the like is divided into the bracket portion 171 and the gear cover 172. It is composed. A shaft hole 174 for rotatably supporting the other end portion 102b of the idle shaft 102 is formed in the bracket portion 171. The gear cover 172 is formed with a bearing recess 47 for rotatably supporting one end portion of the drive shaft 4 (left end portion in FIG. 1), and one side of the idle shaft 102 (left side in FIG. 1). ) Is rotatably supported. A shaft through hole 179 is formed. Further, the motor part 3 is provided separately from the bracket part 171 and the gear cover 172. For this reason, the drive shaft 4 and the idle shaft 102 can be easily positioned, and the assembly work of the starter 1 can be facilitated.

  Further, the reduction ratio between the external gear portion 101 b of the idle gear 101 and the external gear portion 70 b of the transmission pinion gear 70 is set so that the rotational speed of the idle gear 101 decreases with respect to the rotational speed of the transmission pinion gear 70. . Thereby, the rotational torque of the idle shaft 102 can be made larger than the rotational torque of the drive shaft 4. In this way, by adjusting the gear ratio between the transmission pinion gear 70 and the idle gear 101, a torque-oriented type or rotation-oriented type starter can be obtained.

  Further, one end portion 102 a (the left end portion 102 a in FIGS. 1 and 8) of the idle shaft 102 passes through the shaft through hole 179 of the gear cover 172 and protrudes outward from the gear cover 172. For this reason, except for the idle gear unit 100 attached to one end portion 102 a of the idle shaft 102, each component constituting the starter 1 can be sealed with the housing 17 or the motor yoke 53. Therefore, it is possible to reliably prevent the meshing failure between the gears and the damage of each bearing due to dust or the like.

Moreover, since the idle shaft 102 and the idle gear 101 are integrally formed, the number of parts can be reduced. For this reason, the assembly work of the starter 1 can be further facilitated.
Further, the clutch mechanism 5 is provided on the drive shaft 4 so that the rotational force of the drive shaft 4 can be transmitted to and cut off from the transmission pinion gear 70. For this reason, when the engine is started, when the overrun state in which the clutch inner 22 is faster than the clutch outer 18 is entered, the rotational force from the ring gear 23 side of the engine can be cut off, and the motor unit 3 and the like. The starter 1 with high reliability can be provided.

  The yoke 25 constituting the electromagnetic device 9 is formed in a bottomed cylindrical shape, and a substantially cylindrical plunger mechanism 37 is provided on the inner peripheral surface side of the yoke 25, and the electromagnetic device 9 is coaxial with the drive shaft 4. It is arranged. For this reason, the structure of the electromagnetic device 9 can be simplified and reduced in size, and the arrangement space of the electromagnetic device 9 can be saved.

  Further, the inner wall of the bracket portion 171 is provided with a reduced diameter portion 171d that is formed with a reduced diameter by a step closer to the one opening 171a than the electromagnetic device 9 (stopper 94). It functions as a retaining portion that prevents the electromagnetic device 9 from slipping out from the bracket portion 171 to the gear cover 172 side. For this reason, the electromagnetic device 9 and the motor unit 3 can be assembled in advance in the bracket portion 171, and the drive shaft 4 and the idle shaft 102 can be assembled in the gear cover 172 in advance.

  Further, the axial length of the drive shaft 4 and the axial length of the rotary shaft 52 are such that the recess 4a of the drive shaft 4 is inserted before the other end 102b of the idle shaft 102 is inserted into the slide bearing 103 of the bracket portion 171. Further, the length is set such that the rotation shaft 52 is not inserted. Further, the axial length of the drive shaft 4 and the axial length of the rotary shaft 52 are set in the recess 4 a of the drive shaft 4 before the positioning pin 184 of the gear cover 172 is inserted into the pin insertion hole 166 of the bracket portion 171. The length is set such that the rotation shaft 52 is not inserted. For this reason, it is possible to connect the concave portion 4a of the drive shaft 4 that is difficult to visually recognize from the outside and the rotating shaft 52 of the motor portion 3 after the circumferential relative positions of the bracket portion 171 and the gear cover 172 are determined. Therefore, the assembling work of the starter 1 can be further facilitated.

A drainage groove 168 is formed in the outer flange portion 171t of the bracket portion 171. The drainage groove 168 and the contact surface 172s of the gear cover 172 constitute a drainage portion (drainage hole) 185. For this reason, the water droplet which generate | occur | produced in the bracket part 171 or the gear cover 172, or was generated by dew condensation can be discharged | emitted rapidly.
Further, since the drainage portion 185 is formed by superimposing the outer flange portion 171t of the bracket portion 171 and the gear cover 172, the shape of the gear cover 172 changes or a bolt for fixing to the housing. Even when the position of the insertion hole 172b is changed and the specification of the gear cover 172 is changed, the drain part 185 can be easily configured by using the bracket part 171 in common, and the bracket part It is not necessary to form a drainage portion 185 by forming holes on the side surfaces of the gear 171 and the gear cover 172, and the manufacturing cost can be reduced.

  Further, as a method for assembling the starter 1, a subunit in which the electromagnetic device 9 is assembled in advance to the bracket portion 171 is prepared (electromagnetic device assembling step), and further, the drive shaft 4 and the idle shaft 102 are assembled to the gear cover 172 (preliminary assembling step). Then, the bracket part 171 and the gear cover 172 are assembled (bracket part assembling step). For this reason, the assembly work of the starter 1 can be facilitated.

  The present invention is not limited to the above-described embodiment, and includes various modifications made to the above-described embodiment without departing from the spirit of the present invention.

  For example, in the above-described embodiment, the helical spline 19 is formed on the drive shaft 4, the helical spline 18 b is formed on the clutch outer 18, and the clutch mechanism 5 is spline-engaged with the drive shaft 4, thereby driving the clutch mechanism 5. The case where it is possible to slide in the axial direction with respect to the shaft 4 has been described. At this time, the inclination angles of the helical spline 19 of the drive shaft 4 and the helical spline 18b of the clutch outer 18 are such that when the switch plunger 27 and the gear plunger 80 begin to slide toward the ring gear 23, the clutch outer 18 It is only necessary to set so as to be extruded while slightly rotating relative to the surface.

In the above-described embodiment, the spline 108 is formed on the distal end side of the idle shaft 102, while the spline 110 a that meshes with the spline 108 is formed on the distal end side of the inner peripheral surface of the drive pinion gear 110. As a result, the idle shaft 102 and the drive pinion gear 110 are provided such that they cannot rotate relative to each other and can slide in the axial direction.
However, as described above, the present invention is not limited to the case where the idle shaft 102 and the drive pinion gear 110 are formed to be slidable by spline engagement. For example, the idle shaft 102 may be provided with a key, while the drive pinion gear 110 may be provided with a key groove so that the idle shaft 102 and the drive pinion gear 110 are slidable.

  Further, when the electromagnetic device 9 slides the drive pinion gear 110 and the movable contact plate 8 to one side (left side in FIG. 1), the drive pinion gear 110 is moved to the ring gear 23 before the movable contact plate 8 is turned on. You may make it contact | abut.

Furthermore, in the above-described embodiment, the case where the positioning pin 184 for positioning with the bracket portion 171 is press-fitted and fixed to the gear cover 172 at one place has been described. However, the present invention is not limited to this, and it is only necessary that the positioning pin 184 is provided on either the gear cover 172 or the bracket portion 171, and the positioning pin 184 is not press-fitted and fixed to the gear cover 172 or the bracket portion 171. You may form integrally. Further, a plurality of positioning pins 184 may be provided.
When a plurality of positioning pins 184 are provided, the gear cover 172 may not be provided with the spigot portion 173c.

  In the above-described embodiment, the starter 1 used for starting the automobile is described as an example. However, the application of the starter 1 is not limited to the automobile. For example, a motorcycle, an engine-type power generator is used. You may apply to a machine etc.

Furthermore, in the starter 1 of the above-described embodiment, the drive pinion gear 110 and the ring gear 23 can be helically meshed stably as described above. Therefore, among the vehicles to which the starter 1 is applied, the starter 1 is particularly suitable for a vehicle having an idling stop function that is frequently used.
In addition to this, the configuration described in the above embodiment can be selected or changed to another configuration as appropriate without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Starter 3 ... Motor part 4 ... Drive shaft 5 ... Clutch mechanism 9 ... Electromagnetic device 23 ... Ring gear 24 ... Excitation coil 70 ... Transmission pinion gear (transmission gear)
80 ... Gear plunger 101 ... Idle gear 102 ... Idle shaft 110 ... Drive pinion gear (drive gear)
168 ... Water drain groove 171 ... Bracket part 172 ... Gear cover (gear cover part)
185 ... Drain part

Claims (10)

A motor unit that generates rotational force when energized;
A drive shaft that rotates in response to the rotational force of the motor unit;
A transmission gear slidably provided on the drive shaft;
An idle shaft that extends in a direction parallel to the drive shaft, is rotatable around a central axis, and is slidable in the central axis direction in conjunction with the sliding movement of the transmission gear;
An idle gear provided on one axial end of the idle shaft and meshing with the transmission gear;
A drive gear provided on the other axial end of the idle shaft and meshable with an engine ring gear;
A gear cover portion that rotatably supports a part of the drive shaft and the idle shaft, and accommodates the transmission gear and the idle gear;
A bracket portion provided between the motor portion and the gear cover portion, and rotatably supporting one axial end of the idle shaft;
A starter comprising:   2. The starter according to claim 1, wherein the other end side in the axial direction of the idle shaft protrudes from the gear cover portion toward the outer side in the axial direction, and the drive gear is provided at the protruding portion.   The starter according to claim 1 or 2, wherein the idle shaft and the idle gear are integrally formed. A clutch mechanism that is provided between the transmission gear and the motor unit and transmits and interrupts the rotational force of the drive shaft to the transmission gear;
An electromagnetic device that is provided in the bracket portion, energizes and shuts off the motor portion, and generates a pressing force toward the ring gear on the drive gear via the clutch mechanism;
The starter according to any one of claims 1 to 3, further comprising: The electromagnetic device is
An excitation coil, and a gear plunger that slides along the drive shaft based on energization of the excitation coil and generates a pressing force in the clutch mechanism, and is provided coaxially with the drive shaft. The starter according to claim 4. The bracket portion is
The electromagnetic device is assembled in the bracket portion, and the motor portion is assembled into a subunit, and the bracket portion is provided with a retaining portion for restricting the electromagnetic device from being removed from the bracket portion to the gear cover portion side. The starter according to claim 5, wherein the starter is provided.   The starter according to any one of claims 1 to 6, wherein a drainage portion is provided on a contact surface between the gear cover portion and the bracket portion.   8. The drainage groove is formed in the contact surface of the bracket portion, and the drainage portion is configured by the drainage groove and the contact surface of the gear cover portion. Starter. A starter assembling method according to any one of claims 1 to 8,
A preliminary assembling step of assembling the drive shaft, the transmission gear, the idle gear and the idle shaft in advance to the gear cover portion;
After the preliminary assembling step, a bracket portion assembling step for assembling the bracket portion to the gear cover portion,
A starter assembling method characterized by comprising: Before the bracket part assembling step, the bracket unit has an electromagnetic device assembling step for assembling an electromagnetic device that generates a pressing force toward the ring gear on the drive gear,
The starter assembly method according to claim 9, wherein the bracket unit assembly step is performed in a state where the electromagnetic device is assembled to the bracket unit by the electromagnetic device assembly step.