JP6004074B2 - Starter - Google Patents

Description

  The present invention relates to a starter for starting an engine.

  Conventionally, an automatic engine stop / restart device (hereinafter, referred to as an idle stop device) that automatically controls stop and restart of the engine is known.

  For example, the idle stop device disclosed in Patent Document 1 includes pinion pushing means for pushing a pinion gear to the ring gear side, and motor energizing means for turning on / off the energization current of the motor, and the pinion pushing means and the motor energizing The means can be operated independently and independently. With this configuration, even if a restart request is generated during the deceleration period before the engine is completely stopped, the pinion gear is pushed into the rotating ring gear and engaged, and the motor is energized after the engagement is established. It is possible to restart the engine. According to this method, it is not necessary for the driver to feel that the restart is slow as compared with the case where the restart is performed after the engine is completely stopped.

  Further, according to the known technique according to Patent Document 1, even when the restart request is not generated during the deceleration period of the engine, the pinion gear is engaged with the ring gear when the rotation speed of the ring gear decreases to a predetermined rotation speed. It is also possible to keep the pinion gear engaged with the ring gear until the engine is completely stopped without energizing the motor. In this case, when the restart request is next generated, the pinion gear is already engaged with the ring gear, so that the time required for restart can be shortened.

Japanese Patent Laying-Open No. 2005-330813

  By the way, when the number of vehicles equipped with an idle stop device increases, for example, it is assumed that many vehicles start the engine at the same time on a general road in a traffic jam. There is concern about noise problems.

  The main operation noise of the starter is the collision sound generated when the end face of the pinion gear collides with the end face of the ring gear, the collision sound between the tooth faces when the pinion gear is actually engaged with the ring gear, and the pinion pushing means This is considered to be divided into the operation sound of the electromagnetic solenoid (the collision sound generated when the plunger collides with the iron core).

  However, as described above, when the pinion gear is engaged with the rotating ring gear during the deceleration period of the engine and the motor is not energized, the plunger of the electromagnetic solenoid moves the iron core substantially simultaneously with the end surface of the pinion gear colliding with the end surface of the ring gear. The impact sound resulting from the collision between the two is added and generated. In addition, since the motor is not energized at this time, no sound is generated due to the driving of the motor, and as a result, only the impact sound is conspicuous, and this causes discomfort to the driver. Yes.

  The present invention has been made based on the above circumstances, and an object of the present invention is to provide a starter that can reduce the noise generated at the time of starting the engine by mitigating the impact generated when the pinion gear and the ring gear collide. .

(Invention of Claim 1)
The present invention includes a motor that generates a rotational force when energized;
An output shaft that rotates when the rotational force of the motor is transmitted;
A clutch that fits a helical spline on the outer periphery of the output shaft;
A pinion gear to which the rotational force of the motor is transmitted via the clutch;
The pinion gear is axially integrated with the clutch, and has a function of pushing the pinion gear toward the ring gear of the engine ;
Motor energization means for turning on / off the energization current to the motor;
While independently controlling the operation of the pinion pushing means and the operation of the motor energizing means,
When the engine is stopped, the starter is controlled to push out the pinion gear by the pinion pushing means during the deceleration period before the engine is completely stopped, and extends from the clutch in a cylinder shape in the anti-motor direction. And has an inner tube that holds the pinion gear in a relatively non-rotatable manner and is slidable in the axial direction on the outer periphery of the pinion gear and the inner tube, both of which have a predetermined interval in the axial direction. A gear side pressure receiving surface on the pinion gear side and a tube side pressure receiving surface on the inner tube side are formed, and a buffer member is disposed between the gear side pressure receiving surface and the tube side pressure receiving surface,
The buffer member bends at the time of a collision between a rotating ring gear end surface and a pinion gear end surface during a deceleration period of the engine,
The buffer member is provided with an initial load sufficient to prevent the pinion gear from moving in the motor direction against vibration acceleration acting on the starter from the outside when the pinion gear meshes with the ring gear. To do.

  When the engine is stopped, the starter of the present invention engages the pinion gear with the rotating ring gear by pushing out the pinion gear by the operation of the pinion pushing means even during the deceleration period before the engine is completely stopped. After the meshing is established, the motor can be energized by the operation of the motor energizing means to restart the engine.

  Further, when the pinion gear is pushed out integrally with the clutch to the ring gear side of the engine by the operation of the pinion pushing means and the end surface of the pinion gear collides with the end surface of the ring gear, the shock generated at the time of the collision can be reduced by the buffer member. . As a result, it is possible to suppress the impact from being transmitted to the output shaft or the like, so that the collision sound generated by the collision between the pinion gear and the ring gear is less propagated to the output shaft or the like, and the generated sound at the time of engine start can be reduced .

  The buffer member is given an initial load that can prevent the pinion gear from moving in the direction of the motor against vibration acceleration acting on the starter from the outside when the pinion gear meshes with the ring gear.

  According to the above configuration, when the pinion gear meshes with the ring gear due to the initial load applied to the buffer member, the pinion gear does not move in the motor direction due to external vibration, so that the pinion gear and the ring gear are reliably meshed. be able to.

(Invention of Claim 2)
2. The starter according to claim 1, wherein the initial load is generated when the pinion gear is in a motor direction with respect to vibration acceleration acting on the starter from the outside when the pinion gear is engaged with the ring gear during a deceleration period until the engine is completely stopped. The starter is characterized by an initial load sufficient to prevent movement.

  According to the above configuration, when the pinion gear meshes with the rotating ring gear, the pinion gear can be prevented from moving in the motor direction, so that the contact state between the pinion gear and the rotating ring gear is maintained, and the ring gear and the pinion gear mesh. Since it rotates to a possible position, meshing is established.

It is a general view of a starter. (Example 1) which is sectional drawing of a pinion moving body. It is sectional drawing of the solenoid for pinion extrusion, and the solenoid for motor energization. It is an electric circuit diagram of a starter. (A) Sound pressure generated during starter operation, (b) Engine speed, (c) Starter current waveforms. It is the result of measuring the sound pressure at the time of pinion presetting. (Example 2) which is sectional drawing of a pinion moving body. (Example 3) which is sectional drawing of a pinion moving body. (Example 4) which is sectional drawing of a pinion moving body.

    The mode for carrying out the present invention will be described in detail with reference to the following examples.

Example 1
The starter 1 of this embodiment can be applied to an idle stop device that automatically controls stop and restart of the engine. As shown in FIG. 1, the starter 1 is provided with a motor 2 that generates a rotational force, an output shaft 3 that is driven by the motor 2 to rotate, and an outer periphery of the output shaft 3 that is movable in the axial direction. The pinion moving body (described later), a pinion pushing solenoid 5 that operates to push the pinion moving body in the counter-motor direction (left direction in FIG. 1) via the shift lever 4, and a motor contact (described later) It consists of a motor energizing solenoid 6 that opens and closes. A reduction gear (for example, a planetary gear reduction gear) that reduces the rotation of the armature 2a and transmits it to the output shaft 3 is provided between the armature 2a (see FIG. 4) of the motor 2 and the output shaft 3. You can also

  The pinion moving body includes a clutch 7 and a pinion gear 8 described below.

  As shown in FIG. 1, the clutch 7 has a spline barrel 7a that fits helically on the outer periphery of the output shaft 3, an outer 7b that is provided integrally with the spline barrel 7a, and an inner periphery of the outer 7b. And a roller 7d that interrupts transmission of rotational force between the outer 7b and the inner 7c, and the like, and a well-known one direction that transmits rotational force from the outer 7b to the inner 7c only in one direction. It is provided as a clutch.

  The clutch 7 has an inner tube 9 provided integrally with the inner 7 c, and the inner tube 9 is fitted to the outer periphery of the output shaft 3 via a bearing 10 so as to be relatively rotatable.

  As shown in FIG. 2, the inner tube 9 is provided so as to extend in a cylindrical shape from the inner 7 c in the anti-motor direction (left direction in the drawing), and a straight spline 9 a is formed on the outer periphery along the axial direction. . Further, a flange portion 9b larger than the outer diameter of the straight spline 9a is provided at the inner end portion of the inner tube 9, and the end surface on the axially opposite inner side (the left side in the drawing) of the flange portion 9b is the tube of the present invention. A side pressure receiving surface 9c is formed.

  The pinion gear 8 has a fitting hole that fits on the outer periphery of the inner tube 9, and a straight spline 8 a (see FIG. 2) is formed on the inner periphery of the fitting hole, and the straight spline 8 a is formed in the inner tube 9. It engages with the formed straight spline 9a, rotates together with the inner tube 9, and is arranged so as to be movable in the axial direction on the outer periphery of the inner tube 9. As shown in FIG. 2, the movement of the pinion gear 8 in the counter-clutch direction is regulated by a pinion stopper 11 disposed at the end of the inner tube 9 on the counter-inner side.

  A large-diameter hole having an inner diameter larger than the inner diameter of the fitting hole in which the straight spline 8a is formed is formed on the inner periphery of the pinion gear 8. As shown in FIG. 2, the large-diameter hole is formed on the clutch side (right side in the drawing) from the fitting hole in the axial direction of the pinion gear 8, and a step is provided between the fitting hole and the large-diameter hole. Yes. This step forms a gear side pressure receiving surface 8b of the present invention that faces the tube side pressure receiving surface 9c with a predetermined distance in the axial direction. The inner diameter of the large-diameter hole is formed so as to be slidable on the outer periphery of the flange portion 9 b provided in the inner tube 9.

  The axial length of the pinion gear 8 is slightly longer than the axial distance between the pinion side end surface of the pinion stopper 11 and the tube side pressure receiving surface 9c. In other words, as shown in FIG. 2, the pinion gear 8 has its rear end located slightly on the clutch side from the tube side pressure receiving surface 9c with its axial tip in contact with the pinion side end surface of the pinion stopper 11. ing.

  The buffer member 12 of the present invention is disposed on the inner periphery of the large-diameter hole formed in the pinion gear 8. The buffer member 12 is an elastic body made of, for example, rubber or an elastomer that is a composite material of rubber and resin, and an initial load is applied between the tube-side pressure receiving surface 9c and the gear-side pressure receiving surface 8b. It is pinched in a state where the elasticity is stored. The pinion gear 8 is pressed against the pinion stopper 11 by the initial load applied to the buffer member 12. The initial load applied to the buffer member 12 is desirably large enough to prevent the pinion gear 8 from moving in the anti-pinion stopper direction against vibration acceleration acting on the starter 1 from the outside.

  Next, the pinion pushing solenoid 5 and the motor energizing solenoid 6 will be described.

  The pinion push-out solenoid 5 and the motor energization solenoid 6 have a fixed iron core 13 that is commonly used for both, and are configured integrally in the axial direction with the fixed iron core 13 interposed therebetween, as shown in FIG. The starter housing 14 is fixed in parallel with the motor 2.

  As shown in FIG. 3, the pinion push-out solenoid 5 includes a solenoid case 15, an excitation coil 16 accommodated in the solenoid case 15, and an axial center facing the fixed iron core 13 in addition to the fixed iron core 13. A plunger 17 that is movable in the direction, a joint 18 that transmits the movement of the plunger 17 to the shift lever 4, and the like.

  As shown in FIG. 4, the exciting coil 16 has one end connected to the connector terminal 19 and the other end connected to the surface of the fixed iron core 13 by welding or the like and grounded. The connector terminal 19 is connected to electrical wiring connected to the starting relay 20.

  The start relay 20 is on / off controlled by an ECU 21 (electronic control unit) that controls the operation of the starter 1. When the start relay 20 is on-controlled, the exciting coil 16 is energized from the battery 22 through the start relay 20. .

  When the fixed iron core 13 is magnetized by energizing the exciting coil 16, the plunger 17 is attracted to the fixed iron core 13 against the reaction force of the return spring 23 disposed between the plunger 17 and the plunger 17. The plunger 17 is provided in a substantially cylindrical shape having a cylindrical hole in the central portion in the radial direction. The cylindrical hole opens on one end side in the axial direction of the plunger 17 (left end side in FIG. 3), and has a bottom surface on the other end side in the axial direction.

  The joint 18 is inserted into the cylindrical hole of the plunger 17 together with the drive spring 24. The joint 18 is provided in a rod shape, and an engagement groove 18 a that engages one end of the shift lever 4 is formed at one end protruding from the cylindrical hole of the plunger 17, and at the other end. A flange portion 18b is provided. The flange portion 18 b has an outer diameter that is slidable on the inner periphery of the cylindrical hole, and is pressed against the bottom surface of the cylindrical hole under the load of the drive spring 24.

  In the drive spring 24, after the plunger 17 moves, the axial end surface of the pinion gear 8 pushed out in the anti-motor direction via the shift lever 4 comes into contact with the axial end surface of the ring gear 25, and then the plunger 17 contacts the fixed iron core 13. It is compressed while moving until it is attracted, and a reaction force for causing the pinion gear 8 to be engaged with the ring gear 25 is stored.

As shown in FIG. 3, the motor energizing solenoid 6 includes, in addition to the fixed core 13, a cylindrical yoke 26 integrally provided with the solenoid case 15 by extending the opening side of the solenoid case 15 in the axial direction. The exciting coil 27 disposed on the inner periphery of the yoke 26, the plunger 28 that moves in the axial direction facing the fixed iron core 13, and the resin contact cover 29 that is assembled by closing the opening of the yoke 26. The two terminal bolts 30, 31 fixed to the contact cover 29, the set of fixed contacts 32 connected to the motor circuit via the two terminal bolts 30, 31, and the set of fixed It is comprised from the movable contact 33 etc. which electrically connect between the contacts 32.

  As shown in FIG. 4, the exciting coil 27 has one end connected to the external terminal 34 and the other end connected to the surface of the fixed iron core 13 by welding or the like and grounded. The external terminal 34 protrudes from the end surface of the contact cover 29 and is connected to an electrical wiring connected to the ECU 21.

  An annular magnetic plate 35 that forms part of the magnetic circuit is disposed on the side of the exciting coil 27 opposite to the fixed core. In the magnetic plate 35, the outer peripheral end surface on the coil side (left side in the drawing) is in contact with a step provided on the inner periphery of the yoke 26, and the position on the coil side is regulated.

  When the fixed iron core 13 is magnetized by energizing the exciting coil 27, the plunger 28 is attracted to the fixed iron core 13 against the reaction force of the return spring 36 disposed between the plunger 28 and the plunger 28.

  The contact cover 29 has a cylindrical leg portion 29a. The leg portion 29a is inserted inside the yoke 26, and the end surface of the leg portion 29a is in contact with the surface of the magnetic plate 35. 26 is overtightened and fixed. The two terminal bolts 30 and 31 are a B terminal bolt 30 to which a battery cable 37 (see FIG. 4) is connected and an M terminal bolt 31 to which a motor lead wire 38 (see FIG. 1) is connected.

  For example, the set of fixed contacts 32 is provided separately from the two terminal bolts 30 and 31, and is fixed to the two terminal bolts 30 and 31 inside the contact cover 29.

  The movable contact 33 is disposed on the side opposite to the plunger (on the right side in the drawing) from the set of fixed contacts 32, and is pressed against the end face of the resin rod 39 fixed to the plunger 28 under the load of the contact pressure spring 40. . However, since the initial load of the return spring 36 is set larger than the initial load of the contact pressure spring 40, the movable contact 33 is in a state where the contact pressure spring 40 is compressed when the exciting coil 27 is not energized. It is seated on the inner seating surface of the cover 29.

  The motor contact is formed by a set of fixed contacts 32 and a movable contact 33, and the movable contact 33 abuts on the set of fixed contacts 32 and is urged by a contact pressure spring 40. When the electrical contact is established, the motor contact is closed, and the movable contact 33 is separated from the set of fixed contacts 32, and the electrical connection between the fixed contacts 32 is interrupted, thereby opening the motor contact.

  Next, the operation of the starter 1 will be described.

  a) When normal engine start is performed “when the engine is completely stopped and the user turns on an ignition switch (not shown) to start the engine”.

  In response to the engine start signal generated by turning on the ignition switch, the ECU 21 turns on the start relay 20. Thereby, the excitation coil 16 of the pinion push-out solenoid 5 is energized from the battery 22, and the plunger 17 is attracted and moved by the magnetized fixed iron core 13. As the plunger 17 moves, the pinion gear 8 is pushed together with the clutch 7 in the counter-motor direction via the shift lever 4, and the end surface of the pinion gear 8 comes into contact with the end surface of the ring gear 25 and stops.

  After a predetermined time has elapsed from the generation of the engine start signal, an ON signal is output from the ECU 21 to the excitation coil 27 of the motor energizing solenoid 6. As a result, the excitation coil 27 is energized, the plunger 28 is attracted to the fixed iron core 13, and the movable contact 33 comes into contact with the set of fixed contacts 32 and is urged by the contact pressure spring 40 to close the motor contact. To do. As a result, the motor 2 is energized to generate a rotational force in the armature 2 a, the rotational force is transmitted to the output shaft 3, and the rotation of the output shaft 3 is transmitted to the pinion gear 8 via the clutch 7. When the pinion gear 8 rotates to a position where it can mesh with the ring gear 25, the pinion gear 8 is meshed with the ring gear 25 by the reaction force stored in the drive spring 24, and the rotational force is transmitted from the pinion gear 8 to the ring gear 25 to crank the engine. .

When the engine is started, the energization of the excitation coil 16 of the pinion push-out solenoid 5 and the excitation coil 27 of the motor energization solenoid 6 is stopped by the off signal output from the ECU 21. As a result, the suction force of the pinion push-out solenoid 5 disappears and the plunger 17 is pushed back, so that the pinion gear 8 disengages from the ring gear 25 and rests on the outer periphery of the output shaft 3 integrally with the clutch 7 (see FIG. 1). Back to the indicated position) and stop. Further, when the attraction force of the motor energizing solenoid 6 disappears and the plunger 28 is pushed back, the motor contact is opened, the power supply from the battery 22 to the motor 2 is stopped, and the rotation of the armature 2a is gradually decelerated and stopped. To do.

  b) When idling stop is performed from the idling state or when the ignition switch is operated to the engine stop position by the user.

  An engine stop signal is output from the ECU 21, and fuel injection and intake air supply to the engine are stopped. As a result, the engine enters a stop process, and the rotation of the ring gear 25 (indicated by the engine speed in the figure) starts to drop as shown in FIG. 5B. When the rotation of the ring gear 25 is reduced to a predetermined rotation speed set in advance, an ON signal is output from the ECU 21 to the excitation coil 16 of the pinion pushing solenoid 5. As a result, when the pinion gear 8 is pushed together with the clutch 7 in the counter-motor direction and the end surface of the pinion gear 8 abuts on the end surface of the ring gear 25, the ring gear 25 rotates to a position where it can mesh with the pinion gear 8. The meshing of the gears 8 and 24 is established.

  Thereafter, the ring gear 25 continues to rotate down and stops, and the pinion gear 8 stops rotating together with the ring gear 25 while maintaining the state of meshing with the ring gear 25. During this period, the exciting coil 16 of the pinion push-out solenoid 5 is energized with a holding current that can hold the meshed state of the pinion gear 8 and the ring gear 25 as shown in FIG.

  Hereinafter, in the process of stopping the engine, operating the pinion pushing solenoid 5 while the ring gear 25 is rotating to engage the pinion gear 8 with the ring gear 25 is referred to as pinion preset. During the pinion preset, the exciting coil 27 of the motor energizing solenoid 6 is not energized.

  c) Engine restart after pinion preset.

  Next, when an engine restart signal is output from the ECU 21, the exciting coil 27 of the motor energizing solenoid 6 is energized, and the motor contact is closed. As a result, the motor 2 is energized and a rotational force is generated in the armature 2a. At this time, since the pinion gear 8 is already engaged with the ring gear 25, the rotational force of the motor 2 is transmitted from the pinion gear 8 to the ring gear 25 to crank the engine.

(Effect of Example 1)
The starter 1 of the present embodiment can control the operation of the pinion push-out solenoid 5 and the operation of the motor energization solenoid 6 individually by the ECU 21. Therefore, when the engine is stopped from the idling state, the starter 1 Even after only the solenoid 5 is operated to engage the pinion gear 8 with the rotating ring gear 25 and the rotation of the ring gear 25 stops, the state where the pinion gear 8 and the ring gear 25 are engaged can be maintained. Thereafter, when the engine is restarted, since the pinion gear 8 is already engaged with the ring gear 25, it is only necessary to operate the motor energizing solenoid 6 to close the motor contact. That is, it is not necessary to push out the pinion moving body when the engine is restarted, and the time until the pinion gear 8 meshes with the ring gear 25 can be shortened, so that the engine can be restarted quickly.

  By the way, when performing pinion presetting, since the plunger 17 of the pinion push-out solenoid 5 collides with the fixed iron core 13 almost simultaneously with the end surface of the pinion gear 8 colliding with the end surface of the ring gear 25, the impact sound resulting from the collision between the two. It is generated by adding up. When the sound pressure generated during the operation of the starter 1 is measured, the sound level of the impact sound is higher than the operation sound of the starter 1 generated during normal engine start, as shown in FIG. . In addition, when the pinion preset is performed, the motor 2 is not energized, so that no sound is generated due to the driving of the motor 2, and as a result, only the impact sound is noticeable. FIG. 5 shows waveforms of (a) sound pressure generated when the starter 1 is operated, (b) engine speed, and (c) starter current, and point A in FIG. The sound pressure generated when the pinion preset is performed (when the pinion pushing solenoid 5 is operated while the ring gear 25 is rotating and the pinion gear 8 is engaged with the ring gear 25) is shown.

  On the other hand, in the starter 1 of this embodiment, the buffer member 12 is incorporated in the pinion moving body. Specifically, between the tube side pressure receiving surface 9c formed by the flange portion 9b of the inner tube 9 and the gear side pressure receiving surface 8b formed by the step between the fitting hole and the large diameter hole of the pinion gear 8, A buffer member 12 which is an elastic body such as rubber or elastomer is disposed. Thereby, when the end surface of the pinion gear 8 collides with the end surface of the ring gear 25, the shock at the time of collision is reduced by the buffer member 12 being bent between the tube side pressure receiving surface 9c and the gear side pressure receiving surface 8b. The sound generated by the starter 1 due to propagation of the impact at the time of collision to the output shaft 3 or the like can be reduced.

  FIG. 6 shows the result of measuring the sound pressure at the point A shown in FIG. 5A using the starter 1 of the present embodiment in which the buffer member 12 is incorporated in the pinion moving body and the conventional starter without the buffer member 12. Shown in Note that the horizontal axis in FIG. 6 indicates the number of meshing rotations between the pinion gear 8 and the ring gear 25, and the vertical axis indicates the sound pressure. As shown in FIG. 6, compared with the conventional starter, the starter 1 of the present embodiment was able to reduce the sound pressure at the time of pinion presetting.

  As described above, according to the starter 1 of the present embodiment, noise generated when the engine is restarted after idling stop (generated sound of the starter 1) can be reduced, so that it is comfortable for the user without impairing the environment along the road. An idle stop device can be provided.

  Further, in the pinion moving body of the present embodiment, since the buffer member 12 is disposed on the inner periphery of the large-diameter hole formed in the pinion gear 8, the spread preventing means of the present invention is provided on the outer periphery side of the buffer member 12. be able to. That is, as shown in FIG. 2, the boss portion 8c of the pinion gear 8 that forms a large-diameter hole is provided on the outer peripheral side of the buffer member 12, so that the boss portion 8c can have a function of an expansion preventing means. The buffer member 12 can be prevented from expanding radially outward by centrifugal force when the pinion moving body rotates. Thereby, when the pinion moving body is pushed out to the ring gear 25 side of the engine and the end face of the pinion gear 8 collides with the end face of the ring gear 25, the function of the buffer member 12 for reducing the impact generated at the time of the collision is not lowered. The desired effect can be exhibited.

  Further, in the pinion moving body of the present embodiment, the maximum diameter of the gear side pressure receiving surface 8b and the tube side pressure receiving surface 9c is smaller than the root diameter of the pinion gear 8, and the minimum diameter of the gear side pressure receiving surface 8b and the tube side pressure receiving surface 9c is. It is formed larger than the outer diameter of the inner tube 9. According to this configuration, the space for disposing the buffer member 12 can be secured between the root diameter of the pinion gear 8 and the outer diameter of the inner tube 9, and the buffer member 12 is disposed within the axial dimension of the pinion gear 8. Therefore, the buffer member 12 can be incorporated into the pinion moving body without increasing the size of the pinion moving body.

(Example 2)
The second embodiment is an example in which a compression coil spring 41 is used for the buffer member 12 as shown in FIG. In this case, since a general-purpose compression coil spring 41 can be used, cost reduction can be achieved.

(Example 3)
The third embodiment is an example in which an elastic body such as rubber or elastomer and a compression coil spring 41 are used in combination with the buffer member 12 as shown in FIG.

  In this case, it is possible to obtain an impact buffering effect by the compression coil spring 41 and an impact damping effect by the elastic body, thereby further enhancing the effect of reducing the generated sound.

Example 4
The fourth embodiment is an example in which the axial length of the tooth portion is shortened with respect to the boss portion 8 c of the pinion gear 8.

  Since the teeth of the pinion gear 8 need only have an axial length necessary for meshing with the ring gear 25, the axial length of the tooth portion is shortened with respect to the boss portion 8c as shown in FIG. You can also On the other hand, the boss portion 8c of the pinion gear 8 can be provided with the function of preventing the expansion of the buffer member 12 on the outer periphery of the large-diameter hole by making the axial length longer than the tooth portion.

1 starter 2 motor 3 output shaft 5 solenoid for pinion extrusion (pinion extrusion means)
6 Motor energizing solenoid (Motor energizing means)
7 Clutch 7 c Clutch inner 8 Pinion gear 8 b Gear side pressure receiving surface 8 c Pinion gear boss (expansion prevention means)
9 Inner tube 9c Tube side pressure receiving surface 11 Pinion stopper 12 Buffer member 25 Ring gear

Claims (2)

A motor that generates rotational force when energized;
An output shaft that rotates when the rotational force of the motor is transmitted;
A clutch that fits a helical spline on the outer periphery of the output shaft;
A pinion gear to which the rotational force of the motor is transmitted via the clutch;
The pinion gear is axially integrated with the clutch, and has a function of pushing the pinion gear toward the ring gear of the engine ;
Motor energization means for turning on / off the energization current to the motor;
While independently controlling the operation of the pinion pushing means and the operation of the motor energizing means,
A starter that is controlled to push out the pinion gear by the pinion pushing means during the deceleration period before the engine is completely stopped when the engine is stopped, and extends in a cylindrical shape from the clutch in the direction opposite to the motor. And has an inner tube that holds the pinion gear in a relatively non-rotatable manner and is slidable in the axial direction on the outer periphery of the pinion gear and the inner tube, both of which have a predetermined interval in the axial direction. A gear side pressure receiving surface on the pinion gear side and a tube side pressure receiving surface on the inner tube side are formed, and a buffer member is disposed between the gear side pressure receiving surface and the tube side pressure receiving surface,
The buffer member bends at the time of a collision between a rotating ring gear end surface and a pinion gear end surface during a deceleration period of the engine,
The buffer member is provided with an initial load sufficient to prevent the pinion gear from moving in the motor direction against vibration acceleration acting on the starter from the outside when the pinion gear meshes with the ring gear. Starter to do. 2. The starter according to claim 1, wherein the initial load is applied to the vibration acceleration acting on the starter from the outside when the pinion gear is engaged with the ring gear during a deceleration period until the engine is completely stopped. A starter characterized by an initial load sufficient to prevent movement in the motor direction.

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