JP2019218933A - Starter - Google Patents

Abstract

To provide a starter capable of further enhancing its waterproof performance, suppressing its manufacturing cost, and reducing its size.SOLUTION: A contact mechanism 7 includes a contact housing 127, a contact cover 136, a switch shaft 30, a first fixed contact plate 161b and a second fixed contact plate 162b, a movable contact plate 8 provided on the switch shaft 30, and an oil seal 143 which seals a space between the contact housing 127 and the contact cover 136 and through which the switch shaft 30 is inserted. The oil seal 143 has a press-in part 152 whose whole periphery is pressed by the contat cover 136. An electromagnetic device 9 includes a shift lever 120 for transmitting the movement of a switch plunger 27 to the switch shaft 30.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a starter mounted on an automobile, for example.

  2. Description of the Related Art As a starter used for starting an automobile, a jump-in type starter in which a pinion gear is jumped into a ring gear when the engine is started and the pinion gear meshes with the ring gear is known. In such a starter, the ring gear is driven by the pinion gear, and the crankshaft is further rotated to start the engine.

The starter is arranged, for example, in an engine room of a vehicle body. For this reason, the starter is required to have waterproofness due to its arrangement environment, and various techniques for improving the waterproof performance of the starter have been proposed.
For example, there is a device in which an electromagnetic device (magnet switch) is provided outside a motor housing of a starter, and a contact case is provided in the electromagnetic device. A waterproof connector attached to a lead wire wired from the key switch side is fitted and fixed to the contact case (for example, see Patent Document 1).
Further, in a starter in which an electromagnetic device is provided outside the motor housing as in Patent Literature 1, the pinion gear often jumps into the ring gear by a shift lever that connects the electromagnetic device and the motor.

JP-A-8-240170

By the way, in a situation in which the starter is rapidly cooled from a high-temperature and high-humidity environment such as an engine room, dew condensation water may be generated at the contact. If a water drop adheres to the contact itself, in the above-described related art, there is a possibility that the water drop may enter the starter. In addition, when water droplets attached to the contacts change to ice at a low temperature, conduction of the contacts may not be possible.
Further, in the above-described conventional technology, there is a possibility that the cost of parts such as the provision of a waterproof connector is increased, and the manufacturing cost of the starter is increased.
Further, in the above-described conventional technology, the pinion gear is caused to jump into the ring gear side by the shift lever, so that a large load is likely to be applied to the shift lever. For this reason, there has been a problem that the size of the starter is easily increased to withstand this load.

  Therefore, the present invention provides a starter that can further improve waterproof performance, can reduce manufacturing costs, and can be reduced in size.

  In order to solve the above-described problems, a starter according to the present invention includes a motor unit that generates a rotational force by a first energization, an output shaft that rotates by receiving a rotational force of the motor unit, and at least one of the output shaft. A gear housing that rotatably supports an end on the side, a pinion gear slidably provided on the output shaft and meshable with a ring gear of an engine, and a pinion gear provided outside the gear housing, and the first energization is provided. A contact mechanism for performing a second energization, and an electromagnetic device for urging the pinion gear toward the ring gear side by a second energization and performing on / off control of the contact mechanism, wherein the contact mechanism includes the gear housing. A gear housing side communication portion communicating with the gear housing side communication portion, and a connector provided at a location different from the gear housing side communication portion and communicating with the gear housing side communication portion. A contact housing having a tact cover-side communication portion, a contact cover provided in the contact cover-side communication portion of the contact housing, and communicating with the contact cover-side communication portion, and the contact housing via the contact cover-side communication portion A switch shaft provided slidably in the inside and inside the contact cover along the axial direction; and a switch shaft provided on the contact cover and separately connected to the first power supply and the motor unit. A fixed contact, a movable contact housed in the contact cover, provided at a first end of the switch shaft on the contact cover side, and formed so as to straddle the two fixed contacts; The contact housing and the contact cover are provided in the cover-side communication portion, and And an oil seal through which the switch shaft is inserted.The oil seal has an entire outer peripheral portion pressed by the contact cover, and the electromagnetic device, by the second energization, A plunger movable in a direction for urging the pinion gear to apply a pressing force, the plunger being inserted into the gear housing side communication portion, one end being attached to the plunger, and the other end being the first end of the switch shaft. A shift lever attached to the opposite second end and transmitting the movement of the plunger to the switch shaft.

As described above, the contact mechanism is provided outside the gear housing, and the contact mechanism alone enhances the sealing performance, thereby preventing water droplets from entering the gear housing. The contact mechanism has a contact housing and a contact cover, and further seals between the contact housing and the contact cover with an oil seal. Therefore, intrusion of water droplets into the contact housing can be effectively prevented, and further, intrusion of water droplets into the gear housing can be reliably prevented.
Further, by pressing the entire circumference of the outer peripheral portion of the oil seal with the contact cover, it is possible to enhance the adhesion between the entire circumference of the outer peripheral portion of the oil seal and the contact cover. Moreover, unlike the prior art, the oil seal can reliably prevent water droplets from entering the contact housing without requiring a waterproof connector. Therefore, the waterproof performance of the starter can be improved, and the manufacturing cost of the starter can be reduced.
Further, the electromagnetic device includes a plunger movable in a direction for urging the pinion gear to apply a pressing force, and one end attached to the plunger and the other end attached to the second end of the switch shaft. And a shift lever for transmitting to the shift lever. That is, the switch shaft is operated by the shift lever while the pinion gear is pressed by the plunger. Therefore, the load on the shift lever can be reduced and the shift lever can be miniaturized, as compared with the conventional case where the pinion gear is pressed by the shift lever. As a result, the size of the starter can be reduced, and the starter can be operated efficiently.

  In the starter according to the present invention, the oil seal includes an annular metal base through which the switch shaft can be inserted, and an elastic seal body provided to cover at least an outer peripheral portion of the metal base. An outer peripheral portion of the seal body is pressed radially inward by the contact cover.

With this configuration, the seal body of the oil seal and the contact cover can be securely brought into close contact with each other.
The outer peripheral portion of the seal body is pressed radially inward by the contact cover. For this reason, the outer peripheral portion of the seal body can be uniformly pressed by the contact cover, and the pressing force can be easily applied. That is, for example, when the outer peripheral portion of the seal body is pressed in the axial direction by the contact cover, the outer peripheral portion of the seal body can be pressed uniformly over the entire circumference due to a manufacturing error of the axial end of the contact cover. It becomes difficult. Further, when the seal body is pressed in the axial direction, a structure for urging the contact cover with an axial force is required. For this reason, the waterproof performance of the starter can be reliably improved, and the manufacturing cost of the starter can be reliably reduced.

  In the starter according to the present invention, the seal body has an inner peripheral cylinder formed so as to cover an inner peripheral edge of the metal base, and the first end of the switch shaft is provided on the inner peripheral cylinder. The part side is rotatably supported.

  By providing the oil seal with the role of supporting the switch shaft in this way, the switch shaft can be reliably held and the number of parts can be reduced. Therefore, the operation of the starter can be stabilized, and the manufacturing cost can be reduced.

  The starter according to the present invention is characterized in that at least one annular ridge formed over the entire circumference is provided on the inner peripheral surface of the inner peripheral cylindrical portion.

With this configuration, the contact area between the seal body and the switch shaft can be reduced. Therefore, the sliding friction resistance of the switch shaft with respect to the seal body can be reduced, and the starter can be operated efficiently.
Further, by providing the protruding portion, the sealing performance between the seal body and the switch shaft can be reliably improved.

  In the starter according to the present invention, the first end portion and the inner portion of the switch shaft may be provided on the switch shaft, from the inner peripheral cylindrical portion to the position where the movable contact is attached from the movable contact side. It is characterized in that a resin portion is provided for ensuring insulation between the peripheral cylinder portion and the side opposite to the contact cover.

By providing the resin portion on at least a part of the switch shaft, the weight of the switch shaft can be reduced.
In addition, a resin portion is provided between the inner peripheral cylindrical portion of the seal body and a position where the movable contact is attached from the movable contact side. Therefore, insulation between the switch shaft and the movable contact can be reliably ensured, and malfunction of the starter can be prevented.

  A starter according to the present invention includes a shift holder provided in the gear housing and capable of supporting the shift lever, wherein the shift lever is rotatable between the one end and the other end by the shift lever. It is characterized by being supported.

  With this configuration, the load applied to the shift lever can be received by the shift holder. In addition, since the shift lever is rotatably supported by the shift holder, the resistance when the shift lever is driven can be minimized. Therefore, the starter can be operated more reliably and efficiently, and the size of the starter can be reduced more reliably.

According to the present invention, the contact mechanism is provided outside the gear housing, and the contact mechanism alone enhances the sealing performance, thereby preventing water droplets from entering the gear housing. The contact mechanism has a contact housing and a contact cover, and further seals between the contact housing and the contact cover with an oil seal. Therefore, intrusion of water droplets into the contact housing can be effectively prevented, and further, intrusion of water droplets into the gear housing can be reliably prevented.
Further, by pressing the entire circumference of the outer peripheral portion of the oil seal with the contact cover, it is possible to enhance the adhesion between the entire circumference of the outer peripheral portion of the oil seal and the contact cover. Moreover, unlike the prior art, the oil seal can reliably prevent water droplets from entering the contact housing without requiring a waterproof connector. Therefore, the waterproof performance of the starter can be improved, and the manufacturing cost of the starter can be reduced.

  Further, the electromagnetic device includes a plunger movable in a direction for urging the pinion gear to apply a pressing force, and a plunger having one end attached to the plunger and the other end attached to the second end of the switch shaft. And a shift lever for transmitting to the shift lever. That is, the switch shaft is operated by the shift lever while the pinion gear is pressed by the plunger. Therefore, the load on the shift lever can be reduced and the shift lever can be miniaturized, as compared with the conventional case where the pinion gear is pressed by the shift lever. As a result, the size of the starter can be reduced, and the starter can be operated efficiently.

It is a sectional view of a starter in an embodiment of the present invention. FIG. 2 is an enlarged view of a portion corresponding to a motor unit in FIG. 1. FIG. 2 is an enlarged view of a portion corresponding to a clutch mechanism and a pinion mechanism in FIG. 1. FIG. 2 is a perspective view illustrating a configuration of a part of an electromagnetic device and a contact mechanism according to the embodiment of the present invention. FIG. 2 is an enlarged view of a portion corresponding to the contact mechanism of FIG. 1. It is a perspective view of the contact mechanism in the embodiment of the present invention. FIG. 2 is an enlarged cross-sectional perspective view of a part of the contact mechanism according to the embodiment of the present invention.

  Next, an embodiment of the present invention will be described with reference to the drawings.

(Starter)
FIG. 1 is a sectional view of the starter 1.
In FIG. 1, the stationary state of the starter 1 is shown above the center line, and the energized state of the starter 1 (the state where the pinion gear 74 and the ring gear 23 are engaged) is shown below. The energization state referred to herein means a state in which both the first energization and the second energization described in the claims are performed.

The starter 1 is for generating a rotational force necessary for starting an engine (not shown).
As shown in FIG. 1, the starter 1 is provided with a motor unit 3, an output shaft 4 connected to one side of the motor unit 3 (the left side in FIG. 1), and slidably provided on the output shaft 4. A clutch mechanism 5 and a pinion mechanism 70; a contact mechanism 7 arranged radially outside of the motor section 3 and the clutch mechanism 5 to open and close a power supply path to the motor section 3; a movable contact plate 8 of the contact mechanism 7; An electromagnetic device 9 for moving the pinion mechanism 70 along the axial direction. Note that the axial direction refers to the axial direction of the output shaft 4. The same applies to the following description. In the following description, the circumferential direction of the output shaft 4 is simply referred to as the circumferential direction, and the radial direction of the output shaft 4 orthogonal to the axial direction and the circumferential direction is simply referred to as the radial direction.

(Motor part)
FIG. 2 is an enlarged view of a portion corresponding to the motor unit 3 in FIG.
As shown in FIGS. 1 and 2, the motor unit 3 is connected to a brushed DC motor 51 and a rotating shaft 52 of the brushed DC motor 51, and transmits the rotating force of the rotating shaft 52 to the output shaft 4. And a planetary gear mechanism 2.
The brushed DC motor 51 includes a substantially cylindrical motor yoke 53 and an armature 54 disposed radially inside the motor yoke 53 and rotatably provided with respect to the motor yoke 53. A plurality 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.

An end plate 55 for closing the opening 53a of the motor yoke 53 is provided at an end of the motor yoke 53 on the opposite side (right side in FIG. 1) to the output shaft 4. At the radial center of the end plate 55, a slide bearing 56a for rotatably supporting the other end of the rotary shaft 52 and a thrust bearing 56b are provided.
The armature 54 has a rotating shaft 52, an armature core 58 externally fitted and fixed at a position corresponding to the permanent magnet 57 of the rotating shaft 52, and a planetary gear mechanism 2 side (see FIG. 1) with respect to the armature core 58 of the rotating shaft 52. And a commutator 61 fixed to the outside (left side).

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

The commutator 61 is provided with a plurality of segments 62 along the circumferential direction and at predetermined intervals so as to be electrically insulated from each other.
At the end of the armature core 58 side of each segment 62, there is provided a riser (not shown) which is bent so as to be folded back. The terminal of the coil 59 wound around the armature core 58 is connected to the riser.

(Planetary gear mechanism)
On the opposite side of the motor yoke 53 from the end plate 55, a substantially 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 integrally formed with the rotation shaft 52, a plurality of planetary gears 14 meshed with the sun gear 13, and revolves around the sun gear 13, and an annular inner gear provided on an outer peripheral side of the planetary gear 14. And a tooth ring gear 15.

  The plurality of planetary gears 14 are connected by a carrier plate 16. A plurality of support shafts 16a are erected on the carrier plate 16 at positions corresponding to the respective planetary gears 14, and the planetary gears 14 are rotatably supported here. The output shaft 4 is engaged with the center of the carrier plate 16 in the radial direction by serration engagement.

  The internal gear 15 is integrally formed on the inner peripheral surface of the top plate 12 on the armature core 58 side. A sliding bearing 12a is provided at the radial center of the inner peripheral surface of the top plate 12. The slide bearing 12 a rotatably supports one end 104 a of the output shaft 4 on the rotation shaft 52 side, which is coaxial with the rotation shaft 52.

(Gear housing)
An opening 17a of a bottomed cylindrical gear housing 17 is externally fitted and fixed to the top plate 12. The gear housing 17 is formed by aluminum die casting. The output shaft 4, the clutch mechanism 5, the pinion mechanism 70, the electromagnetic device 9, and the like are housed in the gear housing 17. The gear housing 17 has a role of fixing the starter 1 to an engine (not shown).

  A female screw portion 17b is engraved on the outer peripheral surface of the gear housing 17 on the opening 17a side along the axial direction. Further, a bolt hole 55a is formed in a position corresponding to the female screw portion 17b in the end plate 55 arranged at the end of the motor yoke 53 opposite to the gear housing 17. The motor part 3 and the gear housing 17 are integrated by inserting a bolt 95 into the bolt hole 55a and screwing the bolt 95 into the female screw part 17b.

  A ring-shaped stopper 94 for restricting displacement of the clutch outer 18 to the motor unit 3 side, which will be described later, is provided on the inner wall substantially at the center of the gear housing 17 in the axial direction. The stopper 94 is formed of resin, rubber, or the like, and can reduce an impact when the clutch outer 18 comes into contact.

A bearing recess 47 having a substantially circular cross section is formed coaxially with the output shaft 4 on the bottom 17 c of the gear housing 17. The sliding bearing 17d is press-fitted and fixed in the bearing recess 47. The slide bearing 17d is a radial bearing for rotatably supporting the other end 104b of the output shaft 4 opposite to the rotating shaft 52. The sliding bearing 17d is impregnated with a lubricating oil composed of a desired base oil, so that the output shaft 4 inserted into the inner peripheral surface thereof can smoothly slide.
A thrust plate 50 that receives a thrust load of the output shaft 4 is provided at the bottom of the bearing recess 47.

  At one end 104a of the output shaft 4, a recess 4a into which the end 52a of the rotary shaft 52 on the output shaft 4 side can be inserted is formed. A sliding bearing 4b is press-fitted into the inner peripheral surface of the recess 4a. The output shaft 4 and the rotating shaft 52 are connected by the sliding bearing 4b so as to be relatively rotatable. A helical spline 19 is formed substantially at the center of the output shaft 4 in the axial direction. The helical spline 19 is helically meshed with a clutch outer 18 of the clutch mechanism 5 described later.

(Clutch mechanism)
FIG. 3 is an enlarged view of a portion corresponding to the clutch mechanism 5 and the pinion mechanism 70 of FIG.
As shown in FIGS. 1 and 3, the clutch mechanism 5 includes a substantially cylindrical clutch outer 18 having a bottom, a clutch inner 22 formed concentrically with the clutch outer 18, a peripheral wall 18 a of the clutch outer 18, and a clutch. A cylindrical clutch roller 111 and a coil spring 112 arranged between the inner wall 22a and the peripheral wall 22a; a thrust plate 113 arranged on the opening 18b side of the clutch outer 18; and a thrust plate 113 and the clutch outer 18 And a clutch cover 114 that covers the outside from the outside.

  On the bottom wall 18c of the clutch outer 18, a sleeve 18d is formed so as to protrude toward the motor section 3 at the center in the radial direction. The diameter of the sleeve 18 d is smaller than that of the peripheral wall 18 a of the clutch outer 18, and the sleeve 18 d is fitted around the output shaft 4. A helical spline 18e that meshes with the helical spline 19 of the output shaft 4 is formed on the inner peripheral surface of the sleeve 18d.

  In addition, a step 18f is formed on the inner peripheral surface of the bottom wall 18c of the clutch outer 18 at the connection with the sleeve 18d. The later-described movement restricting portion 20 abuts on the step portion 18f. Further, a plurality of recesses 115 are formed on the inner peripheral surface of the peripheral wall 18a of the clutch outer 18 at equal intervals in the circumferential direction. The clutch roller 111 and the coil spring 112 are housed in the recess 115.

The thrust plate 113 disposed on the opening 18b side of the clutch outer 18 receives the thrust load when the clutch roller 111 and the coil spring 112 are subjected to a thrust load in the direction in which the clutch outer 18 is disengaged. The coil spring 112 is prevented from coming off.
The thrust plate 113 is formed in a substantially annular shape so as to surround the peripheral wall 22a of the clutch inner 22 when viewed from the axial direction.
A clutch cover 114 covers the thus formed thrust plate 113 and the clutch outer 18 from outside. Thus, the clutch outer 18, the clutch roller 111, the coil spring 112, and the thrust plate 113 are integrated.

The inner diameter of the clutch inner 22 is larger than that of the sleeve 18 d of the clutch outer 18. A gap is formed between the clutch inner 22 and the output shaft 4, and the return spring 21 is inserted into the gap.
On the opposite side of the thrust plate 113 of the clutch inner 22 from the motor portion 3, a reduced diameter portion 22b whose outer peripheral surface is reduced in diameter by a step is integrally formed. The thrust plate 113 contacts the step surface of the reduced diameter portion 22b. Further, the end of the clutch inner 22 on the side opposite to the reduced diameter portion 22b abuts on the bottom wall 18c of the clutch outer 18. Thus, the clutch inner 22 is held in the axial direction by the thrust plate 113 and the bottom wall 18c of the clutch outer 18. Therefore, the relative positions of the clutch outer 18 and the clutch inner 22 are determined.

On the one end 104a side (left side in FIG. 1) of the output shaft 4 with respect to the helical spline 19, a substantially ring-shaped movement restricting portion 20 is externally fitted. The movement restricting portion 20 is restricted from moving to one side in the axial direction by the circlip 20a.
The outer diameter of the movement restricting portion 20 is set to a size that can contact the step portion 18f of the clutch outer 18. Thereby, when the clutch mechanism 5 slides to the opposite side to the motor section 3, the sleeve 18d of the clutch outer 18 and the movement restricting section 20 interfere with each other. Thereby, the sliding movement amount of the clutch mechanism 5 is regulated.

The return spring 21 inserted into the output shaft 4 is compressed and deformed between the movement restricting portion 20 and the sleeve 18d of the clutch outer 18. Thus, the clutch outer 18 is constantly urged to be pushed back toward the motor unit 3 side.
In the clutch mechanism 5 configured as described above, a pinion mechanism 70 is integrally provided at the tip of the clutch inner 22.

  With such a configuration, the clutch mechanism 5 transmits the torque from the clutch outer 18 to the clutch inner 22 but does not transmit the torque from the clutch inner 22 to the clutch outer 18. Has a one-way clutch function. That is, when the clutch outer 18 rotates forward, the clutch roller 111 is nipped by the clutch outer 18 and the clutch inner 22. Due to the sliding friction generated thereby, the clutch outer 18 and the clutch inner 22 rotate together.

  On the other hand, when the clutch inner 22 rotates reversely, the clutch roller 111 crushes the coil spring 112 and moves with the clutch inner 22. This prevents the clutch roller 111 from rotating freely, and prevents the rotation of the clutch inner 22 from being transmitted to the clutch outer 18. Then, when the engine is in an overrun state in which the clutch inner 22 is faster than the clutch outer 18 when the engine is started, the rotational force from the ring gear 23 of the engine (not shown) is cut off.

  When the torque difference between the clutch outer 18 and the clutch inner 22 and the rotation speed difference are within a predetermined value, the clutch mechanism 5 transmits the torque to each other, while the torque difference and the rotation speed difference are equal to the predetermined value. The torque limiter function, in which the transmission of the rotational force is interrupted when the torque exceeds the threshold, is provided.

(Pinion mechanism)
The pinion mechanism 70 has a cylindrical pinion inner 71 integrally formed at the tip of the clutch inner 22. Two sliding bearings 72 for slidably supporting the pinion inner 71 on the output shaft 4 are provided on the inner peripheral surface of the pinion inner 71 on both sides in the axial direction.

  Here, from the pinion inner 71 to the clutch inner 22, the outer peripheral surface is formed so as to gradually increase in diameter due to a step. That is, the pinion inner 71 is integrally formed with the first cylindrical portion 171 disposed on one side (the left side in FIG. 3) and the clutch inner 22 side of the first cylindrical portion 171 and has an outer diameter of the first cylindrical portion 171. And a second cylindrical portion 172 set to be larger than the outer diameter of the second cylindrical portion 172. The outer diameter of the second cylindrical portion 172 is set to be the same as the outer diameter of the reduced diameter portion 22b of the clutch inner 22. That is, the outer peripheral surface of the second cylindrical portion 172 and the outer peripheral surface of the reduced diameter portion 22b are smoothly connected.

  A helical spline 73 is formed on the outer peripheral surface of the first cylindrical portion 171. A pinion gear 74 meshable with the ring gear 23 of the engine (not shown) is helically spline-fitted to the helical spline 73.

  A helical spline 74a that meshes with the helical spline 73 is formed on the inner peripheral surface of the pinion gear 74 on the tip side (left side in FIG. 3). This allows the pinion gear 74 to slide while slightly rotating on the pinion inner 71. The teeth of the pinion gear 74 are helical teeth.

Further, on the inner peripheral surface of the pinion gear 74, an enlarged diameter portion 75 having an enlarged diameter due to a step is formed closer to the clutch mechanism 5 than the helical spline 74a. Due to the enlarged diameter portion 75, a storage portion 76 is formed between the first cylindrical portion 171 of the pinion inner 71 and the pinion gear 74. An opening formed on the clutch mechanism 5 side of the storage portion 76 is closed by the second cylindrical portion 172 of the pinion inner 71.
That is, the pinion gear 74 has a distal end side (left side in FIGS. 1 and 3) slidably supported by the first cylindrical portion 171 and a proximal end side (clutch mechanism 5 side, right side in FIGS. 1 and 3). ) Are slidably supported by the second cylindrical portion 172. As a result, the pinion gear 74 slides in the axial direction without much play with respect to the pinion inner 71.

The pinion spring 11 formed so as to surround the outer peripheral surface of the first cylindrical portion 171 is stored in the storage portion 76. When the pinion spring 11 is stored in the storage portion 76, the pinion spring 11 is compressed by the step surface 75 a of the enlarged diameter portion 75 formed on the pinion gear 74 and the end surface 172 a of the second cylindrical portion 172 of the pinion inner 71. It has been transformed. As a result, the pinion gear 74 is urged toward the ring gear 23 with respect to the pinion inner 71.
In addition, a retaining ring 77 is provided on the outer peripheral surface on one side (the left side in FIG. 3) of the pinion inner 71. Thereby, it is possible to prevent the pinion gear 74 from slipping out of the pinion inner 71 to one side of the output shaft 4.

  On the other hand, the teeth of the ring gear 23 are also helical teeth. Here, the torsion direction of the teeth of the ring gear 23 and the pinion gear 74 is such that the pinion gear 74 drives the ring gear 23, that is, the direction in which the ring gear 23 jumps into the pinion gear 74 while rotating at a higher speed than the pinion gear 74 (FIG. 1). , Left direction in FIG. 3). Thus, when the pinion gear 74 and the ring gear 23 mesh with each other, a force that is pushed into the ring gear 23 acts on the pinion gear 74.

(Electromagnetic device)
On the inner peripheral surface of the gear housing 17, a yoke 25 constituting the electromagnetic device 9 is fixedly fitted on the motor unit 3 side of the clutch mechanism 5. The yoke 25 is formed in the shape of a bottomed cylinder made of a magnetic material, and a large portion at the radial center of the bottom 25a is largely opened. An annular plunger holder 26 made of a magnetic material is provided at an end of the yoke 25 opposite to the bottom 25a.
An excitation coil 24 formed in a substantially cylindrical shape is housed in a housing recess 25b formed radially inward by the yoke 25 and the plunger holder 26. The excitation coil 24 is electrically connected to an ignition switch (both not shown) via a connector.

A plunger mechanism 37 is provided between the inner peripheral surface of the exciting coil 24 and the outer peripheral surface of the output shaft 4 so as to be slidable in the axial direction with respect to the exciting coil 24.
The plunger mechanism 37 is disposed between the gear plunger 80 and the inner peripheral surface of the exciting coil 24, and is formed of a magnetic material. The gear plunger 80 is provided in a substantially cylindrical shape so as to surround the outer peripheral surface of the output shaft 4. And a substantially cylindrical switch plunger 27. The gear plunger 80 and the switch plunger 27 are provided concentrically with each other, and are provided so as to be relatively movable in the axial direction.

The gear plunger 80 includes a plunger inner 81 disposed radially inward, a plunger outer 85 disposed radially outward, 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 by resin or the like. The inner diameter of the plunger inner 81 is formed slightly larger than the outer diameter of the output shaft 4 so that it can be extrapolated to the output shaft 4. Thus, the plunger inner 81 is provided to be slidable in the axial direction with respect to the output shaft 4.

An outer flange portion 82 projecting radially outward is integrally formed with an end portion 81a of the plunger inner 81 on the clutch mechanism 5 side. When the plunger inner 81 slides toward the clutch mechanism 5, the end 81 a of the plunger inner 81 comes into contact with the sleeve 18 d of the clutch outer 18. This causes the clutch mechanism 5 and the pinion mechanism 70 to slide toward the ring gear 23.
On the other hand, at the end 81b of the plunger inner 81 on the motor portion 3 side, a plurality of claw portions 83 projecting radially outward are provided in a plurality of positions in the circumferential direction. A groove 84 is formed in the plunger inner 81 on the clutch mechanism 5 side of the claw portion 83 along the circumferential direction.

  The plunger outer 85 is formed in a substantially cylindrical shape with resin or the like, similarly to the plunger inner 81. The inner diameter of the plunger outer 85 is set slightly larger than the outer diameter of the outer flange portion 82 of the plunger inner 81, and is externally inserted into the plunger inner 81.

  An inner flange portion 86 protruding radially inward is integrally formed with an end portion 85a of the plunger outer 85 on the motor portion 3 side. The inner diameter of the inner flange portion 86 is set to be smaller than the outer diameter of the claw portion 83 of the plunger inner 81 and larger than the outer diameter of the bottom of the groove portion 84 of the plunger inner 81. By disposing 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.

  The thickness of the inner flange portion 86 of the plunger outer 85 is set smaller than the width of the groove portion 84 of the plunger inner 81. Thus, a clearance is provided 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 that protrudes radially outward is integrally formed with the end portion 85a of the plunger outer 85 on the motor portion 3 side. The outer flange portion 87 functions as a contact portion that contacts the inner flange portion 28b of the link plunger 28.
A ring-shaped iron core 88 is provided on the outer peripheral surface of the plunger outer 85 on the clutch mechanism 5 side of the outer flange portion 87. The iron core 88 is formed integrally with the plunger outer 85 by, for example, a resin mold. The iron core 88 is attracted by the magnetic flux generated when the excitation coil 24 is energized (second energization in the claims).

A storage portion 90 is formed between an outer flange portion 82 of the plunger inner 81 and an 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 stored in the storage section 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 stored in the storage portion 90. The plunger inner 81 is biased toward the clutch mechanism 5, and the plunger outer 85 is biased toward the motor section 3.

  In the stationary state of the starter 1 (the state above the center line in FIGS. 1 and 3), the end 81a of the plunger inner 81 on the clutch mechanism 5 side and the end of the sleeve 18d of the clutch outer 18 do not come into contact with each other. It has become. Then, the clutch outer 18 is pressed against the stopper 94 by the urging force of the return spring 21. Thus, when the starter 1 is at rest, the clutch mechanism 5 is not pushed out by the biasing force of the plunger spring 91, that is, the pinion mechanism 70 is not pushed out carelessly.

  On the other hand, in the energized state of the starter 1 (the state below the center line in FIGS. 1 and 3), when the gear plunger 80 is maximally displaced toward the clutch mechanism 5, the end 81a of the plunger inner 81 on the clutch mechanism 5 side. Is always in contact with the sleeve 18d of the clutch outer 18. That is, the plunger spring 91 is configured to prevent an axial gap from being formed between the clutch mechanism 5 and the gear plunger 80, and to absorb rattling of the clutch mechanism 5.

  A switch return spring 27a is provided between the switch plunger 27 and the plunger holder 26 forming the storage recess 25b in which the excitation coil 24 is stored. The switch return spring 27a is formed of a leaf spring material. The switch return spring 27a urges the switch plunger 27 toward the motor unit 3 (the right side in FIG. 1) with respect to the plunger holder 26.

  The clutch outer 18 of the clutch mechanism 5 is urged toward the gear plunger 80 by the return spring 21. Therefore, in the stationary state of the starter 1 (above the center line in FIGS. 1 and 3), the clutch mechanism 5 moves the switch plunger 27 to the motor unit 3 side via the gear plunger 80 and the inner flange 28b of the link plunger 28. Is pressed.

An outer flange portion 29 that protrudes radially outward is integrally formed at an end of the switch plunger 27 on the motor portion 3 side. A substantially cylindrical link plunger 28 is press-fitted and fixed to the inner peripheral surface of the switch plunger 27 on the motor section 3 side.
The link plunger 28 has a substantially cylindrical tube portion 28a whose outer peripheral surface is press-fitted into the inner peripheral surface of the switch plunger 27, and an inner flange formed by bending the cylindrical portion 28a radially inward from an end of the clutch mechanism 5 on the clutch mechanism 5 side. A portion 28b and an outer flange portion 28c formed to be bent radially outward from an end of the cylindrical portion 28a on the motor portion 3 side.

The inner flange portion 28b is in contact with and separated from the gear plunger 80. Accordingly, when the switch plunger 27 moves toward the ring gear 23, the gear plunger 80 is initially pressed toward the ring gear 23.
On the other hand, the outer flange portion 28c is arranged at a predetermined distance from the outer flange portion 29 of the switch plunger 27. Therefore, an annular shift lever holding concave portion 31 is formed by the outer flange portion 28c and the cylindrical portion 28a of the link plunger 28 and the outer flange portion 29 of the switch plunger 27. One end of the shift lever 120 is held in the shift lever holding recess 31.

FIG. 4 is a perspective view showing a configuration of a part of the electromagnetic device 9 and the contact mechanism 7.
As shown in FIGS. 1 and 4, the shift lever 120 transmits the movement of the switch plunger 27 to the contact mechanism 7. The shift lever 120 has a lever body 121 extending in the radial direction, a plunger holding part 122 integrally formed at an end of the lever body 121 on the switch plunger 27 side, and an end opposite to the plunger holding part 122 of the lever body 121. And a shaft holding portion 123 integrally formed with the shaft.

  The lever main body 121 has a substantially rectangular cross section. At a substantially central portion in the longitudinal direction of the lever main body 121, a columnar supporting convex portion 121b is formed so as to protrude from two opposed side surfaces 121a. These support projections 121b are rotatably held by a shift holder 124 provided on the outer surface of the top plate 12 on the side opposite to the motor unit 3.

  The shift holder 124 is formed by integrally forming a fixed portion 125 fixed to the top plate 12 and two support arms 126 projecting from the fixed portion 125 toward the lever body 121. The interval between the two support arms 126 is set to be substantially equal to or slightly larger than the width of the two side surfaces 121a of the lever main body 121. The two support arms 126 have through holes 126a at positions corresponding to the support protrusions 121b, into which the support protrusions 121b can be inserted. By inserting the support protrusion 121b into the through hole 126a, the shift holder 124 supports the lever body 121 rotatably about the support protrusion 121b.

  The plunger holding portion 122 integrally formed at the end of the lever main body 121 on the switch plunger 27 side has two arm portions 122a extending along the bottom surface of the shift lever holding concave portion 31, and is formed in a forked shape. I have. Each of the two arms 122a is extended by about １ ／ of the shift lever holding recess 31. For this reason, the plunger holding portion 122 has a shape extending over about a half circumference of the shift lever holding concave portion 31. Each of the arm portions 122a is formed such that the width in the axial direction tapers toward the tip. The axial width at the root of each arm portion 122a is formed to be substantially equal to or slightly smaller than the groove width of the shift lever holding concave portion 31.

A substantially circular fulcrum 122b is formed at the tip of each arm 122a as viewed from the radial direction. The diameter of the fulcrum portion 122b is set substantially equal to the groove width of the shift lever holding recess 31.
With such a configuration, the shift lever 120 is configured such that the axial width of each arm portion 122a is smaller than the groove width of the shift lever holding concave portion 31, and the shift lever holding concave portion 31 Can be slightly swung within.

  On the other hand, the shaft holding portion 123 integrally formed at the end of the lever body 121 opposite to the plunger holding portion 122 has two arm portions 123a extending along the extending direction of the lever body 121. I have. The switch shaft 30 constituting the contact mechanism 7 is interposed between the two arm portions 123a.

(Contact mechanism)
FIG. 5 is an enlarged view of a portion corresponding to the contact mechanism 7 of FIG. FIG. 6 is a perspective view of the contact mechanism 7.
As shown in FIGS. 1, 4, 5, and 6, the contact mechanism 7 has a substantially bottomed cylindrical contact housing 127 provided on the outer peripheral surface of the gear housing 17 and near the opening 17a. ing. The switch shaft 30 is housed in the contact housing 127.

  The contact housing 127 is arranged with the opening 127a facing the motor unit 3 side (the right side in FIGS. 1 and 5). The opening 127a is a contact cover-side communication portion 128 that communicates with a contact cover 136 described later. A fitting portion 127c whose diameter is increased by a step is formed on the inner peripheral surface of the opening 127a. A contact yoke 137 described later is fitted into the fitting portion 127c.

  On the peripheral wall of the contact housing 127, a gear housing-side communication portion 129 that connects the inside of the contact housing 127 and the inside of the gear housing 17 is formed at a position where it contacts the gear housing 17. The communication section 129 on the gear housing side is largely open, and also communicates with the opening 127a.

  A substantially rectangular parallelepiped fixing portion 12b that fits into the gear housing-side communication portion 129 is formed on the top plate 12 that is fixed inside the opening 17a of the gear housing 17 so as to project radially outward. The shift holder 124 is fixed to the fixing portion 12b. That is, the shift holder 124 is located on the gear housing side communication portion 129. The shift lever 120 rotatably supported by the shift holder 124 is interposed in the gear housing 17 and the contact housing 127 via the gear housing side communication portion 129.

  A slide bearing 130 is provided on the bottom 127 b of the contact housing 127. The end of the switch shaft 30 is rotatably and slidably supported by the slide bearing 130.

The switch shaft 30 includes a metal shaft main body 30a, a metal reduced diameter portion 30b that protrudes from the shaft main body 30a toward the bottom 127b of the contact housing 127, and has a diameter slightly reduced from the shaft main body 30a. A resin portion 30c made of resin, which protrudes from the end opposite to the reduced diameter portion 30b of 30a and is formed to be smaller in diameter than the shaft main body 30a, is integrally formed.
An outer flange portion 35 projecting radially outward is integrally formed at an end of the shaft main body 30a on the reduced diameter portion 30b side. The outer flange 35 regulates the movement of a switch shaft spring 158 described later.

  The sliding bearing 130 provided on the bottom 127b of the contact housing 127 supports the tip of the reduced diameter portion 30b on the side opposite to the shaft main body 30a so as to be rotatable and slidable.

  On the shaft main body 30a side of the reduced diameter portion 30b, a constricted portion 132 whose diameter is further reduced by a step than the reduced diameter portion 30b is formed. The constricted portion 132 is inserted between two arm portions 123a constituting the shaft holding portion 123 of the shift lever 120. For this reason, when the shift lever 120 rotates around the support protrusion 121b and the shaft holding portion 123 moves, the switch shaft 30 also slides with this movement.

The axial groove width of the constricted portion 132 of the switch shaft 30 is set slightly larger than the axial width of each arm 123a. Therefore, the inclination of the shift lever 120 with respect to the switch shaft 30 is allowed within a predetermined range.
Further, the constricted portion 132 is formed with two chamfered portions 132a opposed to each other with the central axis of the constricted portion 132 interposed therebetween. A constricted portion 132 is inserted between the two arm portions 123a such that the flat portion 132a is sandwiched between the two arm portions 123a. This prevents the switch shaft 30 from rotating around the central axis of the switch shaft 30.

  The resin portion 30c of the switch shaft 30 protrudes from the contact housing 127 via the opening 127a of the contact housing 127. A flat portion 131 is formed at the tip 30d of the resin portion 30c on the opposite side to the shaft body 30a so as to be tapered. A substantially disk-shaped movable contact plate 8 is slidably inserted into the resin portion 30c on the resin portion 30c. A snap ring 134 is provided at the root of the flat portion 131 of the resin portion 30c (on the side of the shaft body 30a). The retaining ring 134 prevents the movable contact plate 8 from coming off from the resin portion 30c.

  Further, a coil spring 135 is provided on the resin portion 30c so as to surround the resin portion 30c. Both ends of the coil spring 135 are in contact with the end face of the shaft main body 30 a and the end face of the movable contact plate 8. The coil spring 135 is provided between the end face of the shaft main body 30a and the end face of the movable contact plate 8 in a slightly compressed and deformed state. Therefore, the movable contact plate 8 is constantly urged toward the retaining ring 134 by the coil spring 135.

  That is, the movable contact plate 8 is slidably attached to the resin portion 30c of the switch shaft 30 along the axial direction, and is supported by the coil spring 135 in a floating manner. Since the movable contact plate 8 is supported by the resin portion 30c, the movable contact plate 8 is insulated from the shaft main body 30a by the resin portion 30c. In addition, the movable contact plate 8 approaches and separates from a fixed contact 160 provided on a contact cover 136 described later as the switch shaft 30 slides.

FIG. 7 is an enlarged sectional perspective view of a part of the contact mechanism 7.
As shown in FIGS. 5 and 7, the contact cover 136 is formed in a substantially cylindrical shape with a bottom so as to close the opening 127 a of the contact housing 127. The contact cover 136 is arranged with the opening 136a facing the opening 127a of the contact housing 127. The outer peripheral surface of the opening 136a side of the contact cover 136 is formed to have a larger diameter to form a yoke mounting portion 154. The contact yoke 137 is mounted on the yoke mounting portion 154. Then, the contact cover 136 is fixed to the contact housing 127 via the contact yoke 137.

The contact yoke 137 includes an outer peripheral portion 138 that covers the yoke mounting portion 154 of the contact cover 136, an inner flange portion 139 bent radially inward from an end of the outer peripheral portion 138 on the contact housing 127 side, and an inner flange portion 139. A substantially cylindrical fitting portion 140 protruding from the inner peripheral edge toward the contact housing 127 side.
A caulking portion 138a is formed on a peripheral edge of the outer peripheral portion 138 opposite to the inner flange portion 139. On the other hand, an inclined portion 154a is formed on the yoke mounting portion 154 of the contact cover 136 at a position corresponding to the caulking portion 138a. The inclined portion 154a is formed so as to gradually decrease in diameter as the distance from the opening 136a of the contact cover 136 increases. By caulking the caulking portion 138a of the contact yoke 137 to such an inclined portion 154a, the contact cover 136 and the contact yoke 137 are integrated.

  The inner flange portion 139 is formed in a substantially annular shape when viewed from the axial direction. The inner flange portion 139 is sandwiched between the end of the contact housing 127 on the opening 127 a side and the end of the contact cover 136 on the opening 136 a. A part of the inner flange portion 139 is an exposed portion 139a that is exposed to the outside in the radial direction of the contact housing 127. The exposed portions 139a are formed one by one on both sides of the contact housing 127. The exposed portion 139a is provided with a male screw portion 139b protruding toward the contact housing 127 side.

  On the outer peripheral surface of the contact housing 127, a fixing table 141 is formed at a position corresponding to the male screw portion 139b so as to protrude radially outward. The fixing base 141 has a through hole 141a through which the male screw portion 139b can be inserted. The distal end of the male screw portion 139b protrudes through the through hole 141a to the opposite side of the fixed base 141 from the contact cover 136. A nut 142 is screwed into the tip of the protruding male screw portion 139b. Thus, the contact cover 136 is fastened and fixed to the contact housing 127 via the contact yoke 137.

  The outer peripheral surface of the fitting portion 140 is fitted to the fitting portion 127c of the contact housing 127. For this reason, the inside of the contact housing 127 and the inside of the contact cover 136 are communicated via the fitting portion 140. In other words, the opening 127a (contact cover side communication portion 128) of the contact housing 127 communicates the inside of the contact housing 127 with the contact cover 136.

At the inner peripheral edge of the opening 136a of the contact cover 136, an enlarged diameter portion 136b whose diameter is enlarged via a step portion 136c is formed. A substantially disk-shaped oil seal 143 is provided on the enlarged diameter portion 136b.
The oil seal 143 is provided so as to close the fitting portion 140 of the contact yoke 137 (the opening 127a of the contact housing 127). Specifically, the oil seal 143 includes a substantially disc-shaped metal base 144 and a seal body 145 that covers the entire surface of the metal base 144 on the contact housing 127 side.

The metal base 144 has a substantially cylindrical fitting portion 146 formed on the outer peripheral portion and bent toward the contact housing 127. The outer diameter of the fitting portion 146 is set smaller than the inner diameter of the enlarged diameter portion 136b of the contact cover 136. Therefore, a first gap K1 is formed between the fitting portion 146 and the enlarged diameter portion 136b of the contact cover 136.
A through hole 144a through which the shaft main body 30a of the switch shaft 30 can be inserted is formed substantially at the center of the metal base 144 in the radial direction. The hole diameter of the through hole 144a is set to be larger than the shaft diameter of the shaft main body 30a. Therefore, a second gap K2 is formed between the inner peripheral edge of the through hole 144a and the shaft main body 30a.

  The seal body 145 has elasticity. The seal body 145 includes an annular portion 151 formed in a substantially annular shape as viewed from the axial direction so as to cover a surface of the metal base 144 on the side opposite to the contact housing 127, and a first annular portion 151 extending from the outer peripheral surface of the annular portion 151. A substantially cylindrical press-fit portion 152 protrudingly formed so as to fill the gap K1 and a substantially cylindrical bearing portion 153 protruding from the inner peripheral edge of the annular portion 151 so as to fill the second gap K2. It is configured.

The press-fit portion 152 is radially compressed by the fitting portion 146 of the metal base 144 and the enlarged diameter portion 136b of the contact cover 136. That is, the press-fit portion 152 is pressed inward in the radial direction by the large-diameter portion 136 b of the contact cover 136. Further, the movement of the press-fitting portion 152 in the direction away from the contact housing 127 is regulated by the step portion 136c of the enlarged diameter portion 136b.
The bearing portion 153 supports the end of the switch body 30 on the resin portion 30c side of the shaft main body 30a in a rotatable and slidable manner. On the inner peripheral surface of the bearing 153, two annular ridges 155 formed over the entire circumference are provided side by side in the axial direction. The tips of the ridges 155 are slidably contacted with the shaft main body 30a of the switch shaft 30 while being slightly compressed and deformed.

  A substantially disc-shaped spring retainer 156 is provided between the end of the contact cover 136 on the opening 136 a side and the inner flange 139 of the contact yoke 137. The spring retainer 156 is sandwiched between an end of the contact cover 136 on the opening 136 a side and the inner flange 139 of the contact yoke 137. At a radial center of the spring retainer 156, a substantially cylindrical cylindrical portion 157 through which the shaft main body 30a of the switch shaft 30 can be inserted is bent toward the contact housing 127 side. The inner diameter of the cylindrical portion 157 is set sufficiently larger than the shaft diameter of the shaft main body 30a.

  Between the spring retainer 156 and the outer flange portion 35 of the shaft main body 30a, a switch shaft spring 158 formed in a spiral shape so as to surround the periphery of the shaft main body 30a is provided. An end 158a of the switch shaft spring 158 on the spring retainer 156 side surrounds the outer peripheral surface of the cylindrical portion 157 of the spring retainer 156. For this reason, the radial displacement of the end 158 a of the switch shaft spring 158 is restricted by the cylindrical portion 157.

  The switch shaft spring 158 is disposed between the spring retainer 156 and the outer flange portion 35 of the shaft main body 30a in a slightly compressed state. Therefore, the switch shaft spring 158 constantly urges the switch shaft 30 toward the bottom 127b of the contact housing 127 (the force that moves away from the fixed contact 160 described later).

A fixed contact 160 composed of two terminals 161 and 162 of a power terminal 161 and a motor terminal 162 is fixed to the bottom 136d of the contact cover 136.
The power terminal 161 has a substantially cylindrical power terminal body 161a, a first fixed contact plate 161b integrally formed at one end of the power terminal body 161a, and a side opposite to the first fixed contact plate 161b of the power terminal body 161a. And a male screw part 161c integrally formed at the end. The first fixed contact plate 161b is formed in a substantially semicircular shape when viewed from the axial direction, and has a flattened portion 161d.

  The configuration of the motor terminal 162 is basically the same as the configuration of the power supply terminal 161. That is, the motor terminal 162 includes a substantially cylindrical power terminal body 162a, a plate-shaped second fixed contact plate 162b integrally formed at one end of the power terminal body 162a, and a second fixed contact plate of the power terminal body 162a. 162b and an externally threaded portion 162c integrally formed at the opposite end. The second fixed contact plate 162b is formed in a substantially semicircular shape when viewed from the axial direction, and has a flattened portion 162d.

  At the bottom 136d of the contact cover 136, two insertion holes 163 and 164, which are a power terminal insertion hole 163 and a motor terminal insertion hole 164, penetrating in the axial direction, are formed in a radial direction. The power supply terminal 161 is inserted into the power supply terminal insertion hole 163 with the male screw portion 161c facing the power supply terminal insertion hole 163 from the opening 136a side of the contact cover 136. Then, the power terminal 161 is inserted into the power terminal insertion hole 163 until the first fixed contact plate 161b contacts the bottom 136d of the contact cover 136. In a state where the power terminal 161 is completely inserted into the power terminal insertion hole 163, a portion extending from the root of the male screw portion 161 c of the power terminal 161 to the tip protrudes from the bottom 136 d of the contact cover 136.

  In the power supply terminal insertion hole 163, an enlarged diameter portion 163a having an enlarged diameter due to a step is formed on the side opposite to the opening 136a of the contact cover 136. An O-ring 165 and a flange washer 166 are mounted on the enlarged diameter portion 163a. The O-ring 165 seals between the power supply terminal insertion hole 163 and the power supply terminal 161.

  The flange washer 166 is an annular washer having a substantially L-shaped cross section along the axial direction. That is, the flange washer 166 includes a substantially cylindrical fitting portion 166a inserted into the enlarged diameter portion 163a, and an outer flange portion bent and extended radially outward from an end of the fitting portion 166a opposite to the contact cover 136. 166b and 166b are integrally formed. The outer flange 166b is in contact with the outer surface of the bottom 136d of the contact cover 136.

  A first nut 167, a flat washer 168, and a second nut 169 are mounted on the male screw part 161 c of the power terminal 161 on the outer flange part 166 d of the flange washer 166 in this order from the tip side. The first nut 167 cooperates with the flange washer 166 to fasten and fix the power supply terminal 161 to the contact cover 136. The first nut 167 and the flange washer 166 cooperate with the flat washer 168 and the second nut 169 to fix the terminal connector 180 to the contact cover 136.

  The terminal connector 180 is fitted with an external connector (not shown) extending from an external power supply (not shown). The terminal connector 180 is formed in a substantially cylindrical shape so as to surround the first nut 167, the flange washer 166, the flat washer 168, and the second nut 169. On the inner peripheral surface of the terminal connector 180, an inner flange portion 180a protruding radially inward is integrally formed at a position corresponding to between the outer flange portion 166b and the flat washer 168 of the flange washer 166. The inner flange portion 180a is sandwiched between the outer flange portion 166b of the flange washer 166 and the flat washer 168. Therefore, removal of the terminal connector 180 from the contact cover 136 is restricted, and the terminal connector 180 is fixed to the contact cover 136.

  The motor terminal 162 is inserted into the motor terminal insertion hole 164 with the male screw portion 162c facing the opening 136a of the contact cover 136 toward the motor terminal insertion hole 164. The motor terminal 162 is inserted into the motor terminal insertion hole 164 until the second fixed contact plate 162b contacts the bottom 136d of the contact cover 136. In a state where the motor terminal 162 is completely inserted into the motor terminal insertion hole 164, a portion extending from the root to the tip of the male screw portion 162 c of the motor terminal 162 projects from the bottom 136 d of the contact cover 136.

  In the motor terminal insertion hole 164, an enlarged diameter portion 164a that is enlarged by a step is formed on the side opposite to the opening 136a of the contact cover 136. An O-ring 181 and a flange washer 182 are mounted on the enlarged diameter portion 164a. The O-ring 181 seals between the motor terminal insertion hole 164 and the motor terminal 162.

  The flange washer 182 is an annular washer having a substantially L-shaped cross section along the axial direction. That is, the flange washer 182 has a substantially cylindrical fitting portion 182a inserted into the enlarged diameter portion 164a, and an outer flange portion bent and extended radially outward from an end of the fitting portion 182a opposite to the contact cover 136. 182b are integrally formed. The outer flange 182b is in contact with the outer surface of the bottom 136d of the contact cover 136.

  A flange nut 183 is attached to the male screw portion 162c of the motor terminal 162 from above the outer flange portion 182d of the flange washer 182. The flange nut 183 is mounted such that the flange portion 183a contacts the outer flange portion 182d of the flange washer 182. By attaching the flange washer 182 in this manner, the motor terminal 162 is fastened and fixed to the contact cover 136.

  With such a configuration, the movable contact plate 8 is brought into contact with and separated from the first fixed contact plate 161b and the second fixed contact plate 162b as the switch shaft 30 slides. The first fixed contact plate 161b and the second fixed contact plate 162b are oriented so that the flattened portions 161d and 162d face each other across the switch shaft 30 in order to avoid interference with the tip of the resin portion 30c of the switch shaft 30. Are located in When the movable contact plate 8 abuts on the first fixed contact plate 161b and the second fixed contact plate 162b, the power terminal 161 and the motor terminal 162 are electrically connected. Here, the connection terminal 191 is sandwiched between the motor terminal 162 and the flange 183 a of the flange nut 183 and the outer flange 182 d of the flange washer 182. The connection terminal 191 is attached to one end of a lead wire 190 extending from the brush holder unit 33. Thus, the brush holder unit 33 and the motor terminal 162 are electrically connected.

(Brush holder unit)
As shown in FIGS. 1 and 2, a brush holder unit 33 is provided on the motor unit 3 side of the planetary gear mechanism 2 with a separate plate 193 interposed therebetween. The separate plate 193 is a metal plate-shaped member. The separate plate 193 is sandwiched between the end of the motor yoke 53 on the opening 53a side and the end of the gear housing 17 on the opening 17a side. The separate plate 193 has a role of separating the planetary gear mechanism 2 and the motor unit 3 and also has a function as a ground plate by being in contact with the gear housing 17 and the motor yoke 53 (details are described below). See below).

  The brush holder unit 33 has a holder body 40 made of resin. The holder main body 40 is formed so as to surround the commutator 61. A plurality of (for example, four) brushes 41 are arranged on the holder main body 40 so as to be able to advance and retreat toward the inside in the radial direction, that is, toward the commutator 61.

A brush spring 42 is provided on the base end side of each brush 41 opposite to the commutator 61. Each brush 41 is urged toward the commutator 61 by the brush spring 42. Thereby, the tip of each brush 41 slides on the segment 62 of the commutator 61.
Each brush 41 is composed of an anode brush and a cathode brush. Of these, one end of the pigtail 43 is connected to the anode-side brush. The other end of the pigtail 43 is connected to the other end of the lead wire 190 opposite to the connection terminal 191. The lead wire 190 is routed inside and outside the motor yoke 53 via a grommet 44 provided on the motor yoke 53.

  With such a configuration, when the movable contact plate 8 abuts on the first fixed contact plate 161b of the power terminal 161 and the second fixed contact plate 162b of the motor terminal 162, the power terminal 161 and the movable contact plate 8, a voltage is applied to the anode-side brush of the brush 41 via the motor terminal 162, the connection terminal 191, the lead wire 190, and the pigtail 43. Further, a current is supplied to the coil 59 via the commutator 61.

  On the other hand, the cathode side brush of the brush 41 is connected to the separate plate 193 via a pigtail (not shown in FIGS. 1 and 2). For this reason, the cathode brush is electrically connected to the cathode of the battery via the separate plate 193, the gear housing 17, and the vehicle body (not shown).

(Operation of starter)
Next, the operation of the starter 1 will be described with reference to FIG.
As shown in a state above the center line in FIG. 1, when the starter 1 is in a stationary state before the current is supplied to the exciting coil 24, the clutch outer 18 urged by the return spring 21 is connected to the pinion gear 74. The clutch unit 22 is fully urged toward the motor unit 3 (right side in FIG. 1) in a state where the integrated clutch inner 22 is pulled. Then, the clutch outer 18 of the clutch mechanism 5 is stopped at a position where the clutch outer 18 is in contact with the stopper 94, and the engagement between the pinion gear 74 and the ring gear 23 is disconnected.

  When the starter 1 is stationary, a slight clearance is formed between the end 81 a of the plunger inner 81 on the clutch mechanism 5 side and the sleeve 18 d of the clutch outer 18. Therefore, the clutch outer 18 is pressed by the stopper 94 by the urging force of the return spring 21. Thus, when the starter 1 is at rest, it is possible to prevent the biasing force of the plunger spring 91 from pressing the clutch mechanism 5, that is, to prevent the pinion mechanism 70 from being inadvertently pushed toward the ring gear 23.

  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 portion 28c of the link plunger 28 integrated with the switch plunger 27 is in contact with the top plate 12.

  Further, the shift lever 120 in which the plunger holding portion 122 is held by the switch plunger 27 and the link plunger 28 is turned around the support protrusion 121b. Therefore, the shaft holding portion 123 of the shift lever 120 swings in a direction away from the fixed contact 160, that is, toward the bottom 127 b of the contact housing 127. Accordingly, the switch shaft 30 held by the shaft holding portion 123 slides in a direction away from the fixed contact 160. As a result, the first fixed contact plate 161b and the second fixed contact plate 162b of the fixed contact 160 are separated from the movable contact plate 8, and the power terminal 161 and the motor terminal 162 are electrically disconnected.

  When an ignition switch (not shown) of the vehicle is turned on from this state, a current is supplied to the excitation coil 24 (second energization in the claims) to be excited, and a magnetic path through which a magnetic flux passes through the switch plunger 27 and the gear plunger 80 is formed. Is done. Thereby, the switch plunger 27 and the gear plunger 80 slide toward the ring gear 23 side (the left side in FIG. 1).

  Here, when the starter 1 is at rest, the gap (axial clearance) between the switch plunger 27 and the plunger holder 26 is set smaller than the gap (axial clearance) between the iron core 88 of the gear plunger 80 and the plunger holder 26. ing. For this reason, the suction force generated in the switch plunger 27 is larger than the suction force generated in the gear plunger 80, so that the switch plunger 27 attempts to slide before the gear plunger 80.

  At this time, since the link plunger 28 is integrally provided on the inner peripheral surface of the switch plunger 27, the inner flange portion 28b of the link plunger 28 presses the gear plunger 80. By initially pressing the gear plunger 80 toward the ring gear 23, the switch plunger 27 and the gear plunger 80 slide together toward the ring gear 23.

  The clutch outer 18 has a sleeve 18d fitted to the output shaft 4 by a helical spline, and the sleeve 18d 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 toward the ring gear 23, the clutch outer 18 is pushed out while being slightly rotated relative to the output shaft 4 by the inclination angle of the helical spline 18e.

  Further, the pinion mechanism 70 is also pushed out toward the ring gear 23 in conjunction with the sliding movement of the gear plunger 80 via the clutch mechanism 5. Further, when the switch plunger 27 is sucked and slid toward the ring gear 23, the shift lever 120 is rotated, and the shaft holding portion 123 swings in a direction approaching the fixed contact 160. Accordingly, the switch shaft 30 slides in a direction approaching the fixed contact 160. Then, the movable contact plate 8 abuts on the first fixed contact plate 161b and the second fixed contact plate 162b.

  At this time, since the movable contact plate 8 is floatingly supported by the resin portion 30c of the switch shaft 30 so as to be displaceable along the axial direction, the pressing force of the coil spring 135 causes the movable contact plate 8 and each It will be added to the fixed contact plates 161b and 162b. As a result, an appropriate contact pressure is applied between the movable contact plate 8 and each of the fixed contact plates 161b, 162b, and the power supply terminal 161 and the motor terminal 162 are reliably conducted.

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 the anode brushes of the brushes 41, and the coil 59 is energized via the segments 62 of the commutator 61 (claim). 1st energization in the section).
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. Thus, the armature 54 starts rotating. Then, when the armature 54 rotates, the torque of the rotating shaft 52 of the armature 54 is transmitted to the output shaft 4 via the planetary gear mechanism 2, and the output shaft 4 starts rotating.

When the output shaft 4 starts rotating, the pinion gear 74 starts rotating. Further, as the switch plunger 27 and the gear plunger 80 slide toward the ring gear 23, the pinion gear 74 is pushed toward the ring gear 23 while rotating.
At this time, if the pinion gear 74 and the ring gear 23 are out of phase with each other, the pinion gear 74 comes into contact with the ring gear 23 and does not mesh. In this case, the pinion spring 11 accommodated in the accommodating portion 76 of the pinion mechanism 70 is compressed and deformed, and applies an urging force toward the ring gear 23 to the pinion gear 74 while absorbing the impact of the pinion gear 74 against the tooth of the ring gear 23. I do.

That is, even if the pinion gear 74 comes into contact with the ring gear 23 and fails to mesh, the pinion gear 74 continues to rotate in a state in which the urging force toward the ring gear 23 is applied while being in contact with the ring gear 23. Then, when the meshing phase with the ring gear 23 is matched, the pinion gear 74 jumps into the ring gear 23.
In this way, even when the pinion gear 74 is in tooth contact with the ring gear 23, the switch plunger 27 can be pushed out to a predetermined position, and wear of the ring gear 23 and the pinion gear 74 due to tooth contact can be suppressed. 1 can be improved in durability. Further, since the pinion gear 74 is pushed toward the ring gear 23 while rotating, the pinion gear 74 is easily meshed with the ring gear 23.

  When the rotation speed of the output shaft 4 increases after the pinion gear 74 meshes with the ring gear 23, an inertial force acts on the clutch outer 18 meshed with the helical spline 19 of the output shaft 4. At this time, since the pinion gear 74 and the ring gear 23 are helically engaged with each other, a thrust force is generated on the pinion gear 74 in the direction of the ring gear 23 (dive direction). Therefore, the pinion gear 74 moves toward the ring gear 23 (left side in FIG. 1) along the helical spline 19 against the urging force of the return spring 21 by the thrust force.

Further, the clutch outer 18 is also pushed toward the ring gear 23 (left side in FIG. 1) against the urging force of the return spring 21 along the helical spline 19 by inertia force.
At this time, a suction force toward the ring gear 23 is acting on the gear plunger 80. Therefore, the gear plunger 80 slides toward the ring gear 23 while pressing the clutch outer 18 so as to interlock with the sliding movement of the clutch outer 18. Thereby, the pinion gear 74 and the ring gear 23 are meshed at a predetermined meshing position.

When the pinion gear 74 and the ring gear 23 mesh with each other, the rotational force of the output shaft 4 is transmitted to the ring gear 23 via the pinion gear 74. Then, the ring gear 23 rotates a crankshaft (not shown) to start the engine.
When the engine starts and the rotation speed of the pinion gear 74 exceeds the rotation speed of the output shaft 4, the one-way clutch function of the clutch mechanism 5 operates to cause the pinion gear 74 to idle. When the energization of the excitation coil 24 is stopped with the start of the engine, the pinion gear 74 is disengaged from the ring gear 23 by the urging force of the return spring 21 with respect to the clutch outer 18, and the movable contact plate 8 is moved from the fixed contact plate 34. The brushed DC motor 51 stops after being separated. Thus, the operation of the starter 1 is completed.

  Here, since the pinion gear 74 and the ring gear 23 are in helical engagement, when the rotational force of the output shaft 4 is transmitted from the pinion gear 74 to the ring gear 23, the thrust load is applied to the pinion gear 74 in the diving direction (left side in FIG. 1). It takes. Therefore, the engagement between the pinion gear 74 and the ring gear 23 is reliably maintained.

However, when the engine is started by engaging the pinion gear 74 with the ring gear 23, the speed difference between the rotation speed of the ring gear and the rotation speed of the pinion gear when the crankshaft (not shown) passes through the top dead center and the bottom dead center. Repeats the reversal. In such a case, the direction of the thrust load applied to the output shaft 4 also repeats the reverse rotation.
That is, when the rotation speed of the pinion gear 74 is higher than the rotation speed of the ring gear 23, as described above, a thrust load is applied to the output shaft 4 toward one side, and the output shaft 4 slides toward one side. try to.

  On the other hand, when the rotation speed of the ring gear 23 is higher than the rotation speed of the pinion gear 74, a thrust load is applied to the pinion gear 74 in a direction away from the ring gear 23. By repeating this, the thrust load of the output shaft 4 is repeatedly applied to the bottom portion 17c of the gear housing 17. On the other hand, since the thrust plate 50 is provided on the bottom 17c of the gear housing 17, the impact of the output shaft 4 on the bottom 17c of the gear housing 17 can be reduced.

(About the waterproofness of the starter, the function and effect of the oil seal)
Next, the waterproofness of the starter 1 and the operation and effect of the oil seal 143 will be described with reference to FIGS.
As shown in FIGS. 1, 5, and 7, the starter 1 is provided with a gear so that the planetary gear mechanism 2, the clutch mechanism 5, the electromagnetic device 9, and the gear housing 17 in which the pinion mechanism 70 are housed are separated. The contact mechanism 7 is provided on the outer peripheral surface of the housing 17. The contact mechanism 7 includes a substantially bottomed cylindrical contact housing 127 provided on the outer peripheral surface of the gear housing 17 and near the opening 17 a, and a substantially closed contact housing 127 provided so as to close the opening 127 a of the contact housing 127. And a bottom cylindrical contact cover 136. An oil seal 143 is provided between the contact housing 127 and the contact cover 136 so as to close the opening 127a of the contact housing 127 (the communication portion 128 of the contact housing 127 on the contact cover side).

The oil seal 143 includes a substantially disk-shaped metal base 144 and a seal body 145 that covers the metal base 144 from the contact housing 127 side. Then, the contact cover 136 presses the press-fit portion 152 radially inward so as to radially compress the press-fit portion 152 (outer peripheral portion) of the seal body 145. For this reason, the adhesion between the oil seal 143 and the contact cover 136 is enhanced, and it is possible to prevent the water droplet W1 (see FIG. 7) from entering between the oil seal 143 and the contact cover 136.
Since the seal body 145 is provided so as to cover the metal base 144, it is easy to press the seal body 145 with the contact cover 136 by cooperating with the metal base 144.

  Here, for example, when the outer periphery of the seal body 145 is pressed in the axial direction by the contact cover 136, the outer periphery of the seal body 145 is made uniform over the entire circumference due to a manufacturing error of the axial end of the contact cover 136. Is difficult to press. When the seal body 145 is pressed in the axial direction, a structure for urging the contact cover 136 with an axial force is required. On the other hand, in the above-described embodiment, since the press-fit portion 152 (outer peripheral portion) of the seal main body 145 is pressed radially inward by the contact cover 136, the outer peripheral portion of the seal main body 145 is uniformly pressed by the contact cover 136. And the pressing force can be easily applied. For this reason, the waterproof performance of the starter 1 can be reliably improved.

The oil seal 143 has a bearing 153 provided at the center of the seal body 145 in the radial direction. On the inner peripheral surface of the bearing 153, two annular ridges 155 formed over the entire circumference are provided side by side in the axial direction. The tips of the ridges 155 are slidably contacted with the shaft body 30a of the switch shaft 30 while being slightly compressed and deformed.
Therefore, the seal between the oil seal 143 and the switch shaft 30 can be reliably ensured while the switch shaft 30 is rotatably and slidably supported by the oil seal 143. Therefore, the number of members that support the switch shaft 30 can be reduced, and the number of components of the starter 1 can be reduced. Further, it is possible to prevent the water droplet W2 (see FIG. 7) from entering between the oil seal 143 and the switch shaft 30.

  In addition, since the switch shaft 30 is in sliding contact with the ridge 155 of the bearing 153, the contact area between the seal body 145 and the switch shaft 30 can be reduced. Therefore, the sliding friction resistance of the switch shaft 30 against the seal body 145 can be reduced, and the starter can be operated efficiently.

  A power terminal insertion hole 163 through which the power terminal 161 is inserted and a motor terminal insertion hole 164 through which the motor terminal 162 is inserted are formed in the bottom 136d of the contact cover 136. O-rings 165 and 181 are attached to these insertion holes 163 and 164, respectively. Therefore, it is possible to prevent the water droplet W3 (see FIG. 7) from entering between the power terminal 161 and the power terminal insertion hole 163. Further, it is possible to prevent the water droplet W4 (see FIG. 7) from entering between the motor terminal 162 and the motor terminal insertion hole 164.

(About insulation of movable contact plate)
Next, the insulating property of the movable contact plate 8 will be described.
The switch shaft 30 to which the movable contact plate 8 is attached is made of a metal shaft body 30a and a metal projecting from the shaft body 30a toward the bottom 127b of the contact housing 127 and having a slightly smaller diameter than the shaft body 30a. Of the shaft main body 30a and a resin portion 30c made of a resin projecting from the end opposite to the reduced diameter portion 30b and having a smaller diameter than the shaft main body 30a. Since the movable contact plate 8 is attached to the resin portion 30c, insulation between the shaft body 30a and the movable contact plate 8 can be ensured.

  The switch shaft 30 has an end on the resin portion 30c side of the shaft body 30a supported by a bearing portion 153 of the oil seal 143. That is, the portion of the switch shaft 30 protruding from the oil seal 143 into the contact cover 136 is substantially only the resin portion 30c. Therefore, even if the inside of the contact cover 136 is dewed, it is possible to prevent the shaft main body 30a and the movable contact plate 8 from being short-circuited via water droplets. Therefore, malfunction of the starter 1 can be prevented.

  As described above, the above-described starter 1 does not require a waterproof connector as in the related art, and can reliably increase the waterproofness by the oil seal 143. Therefore, the manufacturing cost is reduced because the waterproof connector and the like are not required. Can be suppressed. Further, the starter 1 can be operated stably.

  In addition, the electromagnetic device 9 includes a switch plunger 27 that can move in a direction to apply a pressing force to the pinion mechanism 70 (the pinion gear 74), and a shift lever 120 that transmits the movement of the switch plunger 27 to the switch shaft 30. ing. That is, the switch shaft 30 is operated by the shift lever 120 while the pinion mechanism 70 is pressed by the switch plunger 27. For this reason, the load on the shift lever 120 can be reduced and the shift lever 120 can be downsized, as compared with the case where the pinion mechanism 70 (pinion gear 74) is pressed by the shift lever 120 as in the related art. As a result, the size of the starter 1 can be reduced, and the starter 1 can be operated efficiently.

  Further, a shift holder 124 is provided on the fixing portion 125 of the top plate 12, and the lever main body 121 of the shift lever 120 is rotatably supported by the shift holder 124. Therefore, the load applied to the shift lever 120 can be received by the shift holder 124. Further, since the lever body 121 is rotatably supported by the shift holder 124, the resistance when the shift lever 120 is driven can be minimized. Therefore, the starter 1 can be operated more reliably and efficiently, and the size of the starter 1 can be reduced more reliably.

Note that the present invention is not limited to the above-described embodiment, and includes various modifications of the above-described embodiment without departing from the spirit of the present invention.
For example, the above-described starter 1 can be applied to starting an automobile, a motorcycle, or the like.

  In the above-described embodiment, the contact cover 136 presses the press-fit portion 152 radially inward so as to compress the press-fit portion 152 (outer peripheral portion) of the seal body 145 in the radial direction. explained. However, the present invention is not limited to this, and the outer periphery of the seal body 145 may be axially pressed by the end of the contact cover 136 on the opening 136a side.

  Further, in the above-described embodiment, the switch shaft 30 includes the resin portion 30c made of a resin protruding from the end of the shaft main body 30a opposite to the reduced-diameter portion 30b and having a smaller diameter than the shaft main body 30a. The case has been described. The case where the movable contact plate 8 is attached near the tip 30d of the resin portion 30c has been described. However, the present invention is not limited to this. In a state where the switch shaft 30 is supported by the bearing 153 of the oil seal 143, the movable contact plate 8 is attached from the tip 30d side of the bearing 153 of the switch shaft 30. While reaching the location, insulation between the shaft body 30a (on the opposite side of the contact cover 136 than the bearing 153 of the switch shaft 30) and the tip 30d (here, the meaning of the entire tip of the switch shaft 30) is ensured. What is necessary is just to provide a resin part.

  In the above-described embodiment, the case where the seal body 145 of the oil seal 143 covers the entire surface of the metal base 144 on the contact housing 127 side has been described. However, the present invention is not limited to this, and the seal body 145 only needs to cover at least the outer peripheral portion and the inner peripheral portion of the metal base 144. That is, the seal body 145 only needs to have at least the press-fit portion 152 and the bearing portion 153.

  Further, in the above-described embodiment, the case has been described in which the bearing portion 153 of the oil seal 143 is formed with two protruding portions 155 on the inner peripheral surface. However, at least one ridge 155 may be formed, and three or more ridges 155 may be provided.

DESCRIPTION OF SYMBOLS 1 ... Starter, 3 ... Motor part, 4 ... Output shaft, 7 ... Contact mechanism, 8 ... Movable contact plate (movable contact), 9 ... Electromagnetic device, 17 ... Gear housing, 23 ... Ring gear, 27 ... Switch plunger (plunger) , 28: Link plunger (plunger), 30: Switch shaft, 30a: Shaft main body, 30b: Reduced diameter portion (second end), 30c: Resin portion, 30d: Tip (first end), 70: Pinion mechanism 74, a pinion gear, 80, a gear plunger (plunger), 104b, (one end), 120, a shift lever, 121, a lever body, 122, a plunger holder (one end), 123, a shaft holder (other end) ), 124: shift holder, 127: contact housing, 128: contact cover side communication part, 129: gear housing side communication part, 136: connector 143: oil seal, 144: metal base, 145: seal body, 152: press-fit portion (outer peripheral portion), 153: bearing portion (inner cylindrical portion), 155: convex ridge portion, 160: fixed contact, 161 ... Power supply terminal, 161b: first fixed contact plate (fixed contact), 162: motor terminal, 162b: second fixed contact plate (fixed contact)

Claims (6)

A motor unit that generates a rotational force by the first energization;
An output shaft that rotates by receiving the rotation force of the motor unit,
A gear housing rotatably supporting at least one end of the output shaft;
A pinion gear slidably provided on the output shaft and meshable with a ring gear of an engine;
A contact mechanism that is provided outside the gear housing and performs the first energization;
An electromagnetic device that urges the pinion gear toward the ring gear side by the second energization and controls on / off of the contact mechanism;
With
The contact mechanism,
A contact housing having a gear housing side communication portion communicating with the gear housing, and a contact cover side communication portion provided at a location different from the gear housing side communication portion and communicating with the gear housing side communication portion;
A contact cover provided in the contact cover side communication portion of the contact housing and communicating with the contact cover side communication portion;
A switch shaft slidably provided in the contact housing through the contact cover side communication portion and in the contact cover along the axial direction;
Two fixed contacts provided on the contact cover and separately connected to the first power supply and the motor unit;
A movable contact that is housed in the contact cover, is provided at a first end of the switch shaft on the contact cover side, and is formed to straddle the two fixed contacts;
An oil seal provided in the contact cover side communication portion, for sealing between the contact housing and the contact cover, and through which the switch shaft is inserted;
With
The oil seal is pressed by the contact cover over the entire periphery of the outer peripheral portion,
The electromagnetic device,
A plunger movable in a direction for urging the pinion gear to apply a pressing force by the second energization;
One end is attached to the plunger, the other end is attached to a second end of the switch shaft opposite to the first end, and the movement of the plunger is inserted into the gear housing side communication portion. A shift lever transmitting to the switch shaft,
A starter characterized by comprising: The oil seal,
An annular metal base through which the switch shaft can be inserted,
An elastic seal body provided to cover at least the outer peripheral portion of the metal base,
Has,
The starter according to claim 1, wherein an outer peripheral portion of the seal body is pressed radially inward by the contact cover. The seal body has an inner peripheral cylindrical portion formed to cover an inner peripheral edge of the metal base,
The starter according to claim 2, wherein the first end side of the switch shaft is rotatably supported by the inner peripheral cylindrical portion. 4. The starter according to claim 3, wherein at least one annular convex portion formed over the entire circumference is provided on an inner peripheral surface of the inner peripheral cylindrical portion. 5. In the switch shaft, the contact between the first end portion and the inner peripheral cylinder portion of the switch shaft may be located between the movable contact side from the inner peripheral cylinder portion and a location where the movable contact is attached. 5. The starter according to claim 3, wherein a resin portion for securing insulation from a side opposite to the cover is provided. 6. A shift holder provided in the gear housing and capable of supporting the shift lever;
The starter according to claim 1, wherein the shift lever is rotatably supported between the one end and the other end by the shift lever.

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