Starter having resilient shift lever for driving pinion gear

CROSS REFERENCE TO RELATED APPLICATION

The present application is based on and incorporates herein by reference Japanese Patent Applications No. 2000-7853 filed Jan. 17, 2000, No. 2000-273953 filed Sep. 8, 2000, No. 2000-325479 filed Oct. 25, 2000 and No. 2000-351440 filed Nov. 17, 2000.

BACKGROUND OF THE INVENTION

The present invention relates to improvements in starters, particularly to improvements in a shift lever for driving a pinion gear of a starter.

In a starter disclosed in, for example, Japanese Patent Laid-Open No. 5-180131 and No. 50-65806, a shift lever for driving a pinion gear by an electromagnetic switch is constructed with a resilient drive spring.

The drive spring may comprise two-layered leaf springs supported inclinedly at a middle portion thereof and having contact portions at both ends thereof. However, when the drive spring is operated, loss of kinetic energy by friction is caused because the respective leaf springs slide relative to each other. Therefore, kinetic energy necessary for driving the drive spring is requested to be larger by an amount of the loss by friction and load of an electromagnetic switch is increased by that amount. As a result, the size of the electromagnetic switch is large and heavy, thus consuming larger power.

Further, when a pinion gear is meshed with a ring gear of an engine, return force is exerted to the pinion gear by operation of a helical spline. Therefore, friction heat is generated at an end portion of the shift lever receiving the return force (for example, a portion in contact with a one-way clutch). As a result, there occurs permanent set in fatigue (reduction of resiliency) in the leaf spring by influence of the friction heat.

Moreover, the shift lever has no set load before being brought into contact with a movable cylindrical body including the pinion gear. Since the movable cylindrical body is not kicked impulsively, performance of bringing the pinion gear in mesh with the ring gear becomes insufficient. In the case of the pinion gear and the ring gear fail to mesh each other sufficiently, frictional wear occurs therebetween and the durability becomes insufficient.

SUMMARY OF THE INVENTION

It is therefore an object of the invention to provide a starter capable of improving construction and performance of a shift lever formed by a resilient leaf spring.

According to one aspect of the present invention, a shift lever is constructed with a plurality of leaf springs layered to have gaps at least at end portions thereof where the ends of the springs contact an opposing member such as a movable body of a pinion gear or an electromagnetic switch. As the ends of the springs contact the opposing member at different locations, sliding frictional loss among the springs is minimized.

According to another aspect of the present invention, a shift lever is constructed with a lever holder and a leaf spring. A low heat conductive member is attached to an end portion of the holder so that the low heat conductive member contacts a movable body of a pinion gear. The low heat conductive member suppresses heat transfer between the movable body and the spring at the time of overrun of the pinion gear.

According to a further aspect of the present invention, a shift lever is constructed with a support portion, a lever portion, a leaf spring, and a pin supported by the support portion for pivoting the lever. The lever is constructed to apply a set load to the leaf spring by pinching the leaf spring. Thus, a pinion gear is advanced forward impulsively for engagement with a ring gear of an engine.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the drawings:

FIG. 1

is a sectional view showing partly a starter according to a first embodiment of the present invention;

FIG. 2

is an enlarged view showing a shift lever of the starter in the first embodiment;

FIG. 3

is an enlarged view showing a slit end of the shift lever in the first embodiment;

FIG. 4

is a development view showing a shape of one sheet of leaf spring used in the shift lever in the first embodiment;

FIG. 5

is a sectional view showing partly a first modification of the shift lever in the first embodiment;

FIG. 6

is an enlarged view showing a slit end of the shift lever in the first modification of the first embodiment;

FIG. 7

is an enlarged view showing partly a second modification of the shift lever in the first embodiment;

FIGS. 8A and 8B

are a sectional view and a front view of a shift lever of a starter according to a second embodiment of the present invention, respectively;

FIG. 9

is a partial view showing the shift lever holding a low heat conductive member in the second embodiment;

FIG. 10

is a sectional view showing partly a stationary state of the shift lever in the second embodiment;

FIG. 11

is a sectional view showing partly an operating state of the shift lever in the second embodiment;

FIG. 12

is a sectional view showing a starter according to a third embodiment of the invention;

FIGS. 13A and 13B

are a sectional view and a front view of a shift lever of the starter in the third embodiment, respectively;

FIGS. 14A and 14B

are sectional views showing partly an operating state and a stationary state of the shift lever in the third embodiment, respectively; and

FIGS. 15A and 15B

are a sectional view and a front view of a shift lever of the starter according to a modification of the third embodiment, respectively;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention will be described in detail with reference to various embodiments.

(First Embodiment)

Referring first to

FIG. 1

, a starter includes an electromagnetic switch

3

, a unit of a pinion gear

204

and a one-way clutch

5

movable forward and rearward along an axial direction, and a shift lever

1

for driving the unit of pinion gear

204

and clutch

5

by the electromagnetic switch

3

.

The shift lever

1

comprises a plurality of, for instance three, sheets of resilient leaf springs

1

a

through

1

c

which are layered as shown in FIG.

2

. The shift lever

1

is inclinedly supported at a middle portion

13

thereof and have contact portions at both longitudinal ends

11

and

12

thereof. In this case, the middle portion

13

of the shift lever

1

is held or pinched by a pivot

2

in a cylindrical shape perforated to cross with a through hole and is axially supported to be inclinable in the forward and rearward directions. At the rear end

11

of the shift lever

1

, three sheets of the leaf springs

1

a

through

1

c

are aligned with the same length and layered each other to thereby form an end portion. Further, the rear end

11

of the shift lever

1

is inserted into a through hole

30

formed in a plunger front end portion

32

of the electromagnetic switch

3

and follows movement of the plunger front end portion

32

with predetermined play.

As shown in

FIG. 3

, the front end

12

of the shift lever

1

has a slit portion formed with gaps

120

among the respective leaf springs

1

a

through

1

c

not only at contact portions

121

but up to the vicinity of the middle portion

13

(FIG.

1

). At the front end

12

, the respective leaf springs

1

a

through

1

c

are provided with differences of front end positions ΔL longer than a thickness “t” of each of the leaf springs

1

a

through

1

c

. With respect to a degree of the difference ΔL, the degree is so large as to form a gap (slit) having a predetermined spacing “s” between contiguous ones of the respective leaf springs

1

a

through

1

c

at the front end

12

.

As a result, the leaf springs

1

a

through

1

c

constituting the shift lever

1

are provided with the contact portions

121

in contact with a rear face

51

of the one-way clutch

5

constituting an opposing member at positions of three locations different from each other. Further, grease is coated on the rear face

51

of the one-way clutch

5

with which the front end

12

of the shift lever

1

is brought into sliding contact.

As representatively shown in

FIG. 4

as a development view of the frontmost one of the leaf spring

1

a

, each of the leaf springs

1

a

through

1

c

is a punched-out sheet having substantially a shape of inverse Y and the front end

12

at two locations of lower ends thereof, are brought into contact with the one-way clutch

5

at the contact portions

121

. The respective leaf springs

1

a

through

1

c

are made of spring steel material (SK5 or S60CM in JIS standards).

Referring back to

FIG. 1

, the shift lever

1

is inclinedly supported at the middle portion

13

and the rear end

11

of the shift lever

1

is inserted into the plunger front end portion

32

of the electromagnetic switch

3

. Therefore, when the electromagnetic switch

3

is operated and the plunger front end portion

32

is attracted, the shift lever

1

moves forward forwardly the pinion gear

204

and the one-way clutch

5

at the front end

12

while flexing due to spring resiliency.

In this case, the respective leaf spring

1

a

through

1

c

are bundled together at the middle portion

13

. Accordingly, significant relative displacement is not caused among contiguous ones of the leaf springs

1

a

through

1

c

. Therefore, at the middle portion

13

, even when the respective leaf springs

1

a

through

1

c

are brought into sliding contact with each other, the stroke of the displacement is small. Accordingly, loss of kinetic energy by friction is not caused significantly.

When the electromagnetic switch

3

is operated, bending moment is applied to the shift lever

1

and the respective leaf springs

1

a

through

1

c

flexes and resiliently deforms, at the front end

12

of the respective leaf springs

1

a

through

1

c

, significant relative displacement is caused among the front end

12

. Therefore, when the respective leaf springs

1

a

through

1

c

are brought into contact with each other even at the front end

12

of the shift lever

1

, friction is caused among the respective leaf springs

1

a

through

1

c

causing loss of kinetic energy.

However, the front end

12

of the shift lever

1

has the gaps

120

among the respective leaf springs

1

a

through

1

c

not only at the contact portions

121

but up to a vicinity of the middle portion

13

. Therefore, in the vicinity of the front end

12

having considerable relative displacement, the respective leaf springs

1

a

through

1

c

are not brought into sliding contact with each other and loss of kinetic energy by friction is reduced. As the kinetic energy necessary for driving the shift lever

1

is not increased considerably to compensate for friction loss of the front end

12

of the shift lever

1

, the load of the electromagnetic switch

3

is alleviated and the configuration of the electromagnetic switch

3

need not be enlarged considerably.

Further, as shown in

FIG. 3

, the respective leaf springs

1

a

through

1

c

are respectively provided with the contact portions

121

in contact with the rear face

51

of the one-way clutch

5

at positions different from each other at the front end

12

. Accordingly, press force exerted to the contact portions

121

is dispersed when the electromagnetic switch

3

is operated. Oil films are formed at the respective contact portions

121

since grease is coated on the rear face

51

of the one-way clutch

5

, at the front end

12

, friction force at the contact portions

121

of the shift lever

1

is reduced and friction loss of kinetic energy is further reduced. Further, amounts of wearing the respective contact portions or the opposing member are also reduced.

In the above embodiment, a lever case (not shown) may be provided to contain the front end

12

of the shift lever

1

on the rear side of the one-way clutch

5

. The lever case is held rotatably relative to the one-way clutch

5

via a bearing (not shown) and is moved only in the forward and rearward direction. In this instance, wear of the front end

12

is minimized since the front end

12

of the shift lever

1

is contained in the lever case and is not brought into sliding contact with other member.

(Modification of First Embodiment)

As shown in

FIGS. 5 and 6

, the front end

12

forms a slit end portion having large gaps

120

and front end portions

12

of the respective leaf springs

1

a

through

1

c

are bent to fold back rearwardly. Further, as shown in

FIG. 6

, three sheets of the leaf springs

1

a

through

1

c

constituting the shift lever

1

are respectively provided with contact portions

121

which are brought into contact with the rear face

51

of the one-way clutch

5

by curved faces each having a proper radius of curvature. The slit end portions forming the front end

12

of the shift lever

1

are brought into contact with the rear face

51

of the one-way clutch

5

with the curved faces, and therefore friction and wear at the contact portions

121

are also reduced. That is, since the contact portion

121

of the front end

12

is constructed with the curved face, an oil film of grease is thickly formed between the contact portion

121

and the one-way clutch

5

. Pressure between the contact portion

121

of the front end

12

and the one-way clutch

5

is also considerably reduced. Therefore, not only friction resistance is reduced by the oil film but also the contact portion

121

of the front end

12

and the one-way clutch

5

are not directly brought into sliding contact with each other. Accordingly, wear of the contact portion

121

is considerably reduced. As a result, load of the electromagnetic switch

3

for operating the shift lever

1

is further reduced, the electromagnetic switch

3

is further made to be small-sized and light-weighted.

As a further modification, as shown in

FIG. 7

, the rear end

11

of the shift lever

1

has a slit end portion forming large gaps

110

among three sheets of the leaf springs

1

a

through

1

c

of the shift lever

1

. That is, a rear end of each of the leaf springs

1

a

through

1

c

is respectively press-formed out of an elongated spring steel plate toward its rear side and the rear end

11

of each of the leaf springs

1

a

through

1

c

is bent in a shape of a crank by a predetermined radius of curvature in press-forming thereof. Therefore, not only the rear end

11

of the shift lever

1

is divided into three sheets of the leaf springs

1

a

through

1

c

with gaps thereamong but also each of the leaf springs

1

a

through

1

c

is brought into contact with a contact face

31

of the plunger front end portion

32

at the contact portion

111

having a curved face.

Thus, loss of kinetic energy by friction is remarkably reduced not only at the front end

12

of the shift lever

1

but also at a vicinity of the rear end

11

, and load applied on the electromagnetic switch

3

is reduced.

Further, when the plunger front end portion

32

returns to the original position, there is a case in which the rear end

11

of the shift lever

1

is brought into contact with the plunger front end portion

32

at a contact portion

111

′ of the rear face of the leaf spring

1

c

. In this case, the contact portion

111

′ is brought into contact with the plunger front end portion

32

by a curved face. Therefore, wear is reduced and load of a return spring (not shown) is reduced. Accordingly, there also is achieved an effect in which the return spring can be made weak and load of the electromagnetic switch

3

is reduced by that amount.

(Second Embodiment)

In a second embodiment, as shown in

FIG. 10

, a starter includes an output shaft

201

rotated by being transmitted with rotation of a motor armature (not shown), a one-way clutch

203

(inner

203

a

, roller

3

b

, outer

203

c

) fitted to the output shaft

201

via a helical spline

202

, a pinion gear

204

transmitted with rotation of the output shaft

201

via the one-way clutch

203

, a shift lever

206

for pushing out the pinion gear

204

to a side of a ring gear

200

by receiving attraction force of an electromagnetic switch (not shown), and so on. This starter starts an engine by transmitting rotational force from the pinion gear

204

to the ring gear

200

by bringing the pinion gear

204

move forward via the shift lever

206

in mesh with the ring gear

200

in a known manner.

The shift lever

206

is constructed as shown in

FIGS. 8A and 8B

. Specifically, the shift lever

206

is constructed with a leaf spring

207

made of resilient metal used as a drive spring and a lever holder

208

made of metal for holding the leaf spring

207

. The shift lever

206

is provided with a low heat conductive member

209

at a front end (lower end portion) of the lever holder

208

.

The leaf spring

207

exerts resilient force to the lever holder

208

by engaging a rear end (upper end portion) thereof with a joint point

210

of an electromagnetic switch and with a support pin

211

as a fulcrum. The lever holder

208

holds to incorporate the leaf spring

207

supported pivotably by the support pin

211

and inserted between the support pin

211

and the lever holder

208

. Further, as shown in

FIG. 8B

, the leaf spring

207

and the lever holder

208

are provided such that lower sides thereof are respectively bifurcated and arranged to ride over a barrel

212

of the one-way clutch

203

.

The low heat conductive member

209

is provided at a position which is brought into contact with a rear end face

203

d

of the one-way clutch

203

(

FIG. 10

) when the pinion gear

204

is moved forward to the side of the ring gear

200

via the shift lever

206

. Specifically, as shown in

FIG. 8

, the low heat conductive members

209

are held at two bifurcated lower end portions of the lever holder

208

. The low heat conductive member

209

is molded by, for example, a resin member excellent in wear resistance. It is provided to project to a side forward from a front end face of the lever holder

208

(side of the pinion gear

204

) by a predetermined amount in a plate thickness direction (front and rear direction) of the lever holder

208

. A front end face

209

a

of the low heat conductive member

209

is constructed with a gradually projected curve face (circular arc face) as shown in FIG.

8

A.

Further, the low heat conductive member

209

may adopt a structure in which the low heat conductive member

209

is integrally provided with a lock piece

209

b

and the lock piece

209

b

is supported by the leaf spring

207

as shown in

FIG. 9

to prevent detachment from the lever holder

208

.

When a starter switch (not shown) is turned on, an inner contact of the electromagnetic switch is closed and electricity is conducted to an armature and the armature starts rotating. Rotation of the armature is transmitted to the output shaft

201

via a speed reduction apparatus (not shown) and transmitted further from the output shaft

201

to the pinion gear

204

via the one-way clutch

203

.

By transmitting attraction force of the electromagnetic switch to the one-way clutch

203

via the shift lever

206

, the pinion gear

204

is moved forward to a front side (left direction of

FIG. 10

) on the output shaft

201

integrally with the one-way clutch

203

. The pinion gear

204

is brought in mesh with the ring gear

200

as shown in

FIG. 11

to thereby rotate the ring gear

200

and crank the engine.

After starting the engine, when the starter switch is turned off, the attraction force of the electromagnetic switch is nullified. The pinion gear

204

is pulled back on the output shaft

201

integrally with the one-way clutch

203

via the shift lever

206

, detached from the ring gear

200

and returns to an initial position shown in FIG.

10

. Further, by opening the inner contact of the electromagnetic switch, current to the armature is shut off and rotation of the armature is stopped.

In the above operation, after starting the engine, when the pinion gear

204

is brought into the overrun state while being in mesh with the ring gear

200

, in the one-way clutch

203

, the inner

203

a

rotated integrally with the pinion gear

204

is idly rotated and idle rotation torque thereof is transmitted to the outer

203

c

via the roller

203

b

. As a result, rotation of the outer

203

c

is converted into force of regressing on the output shaft

201

by operation of the helical spline

202

. Accordingly, the pinion gear

204

is exerted with return force. At this occasion, as shown in

FIG. 11

, the low heat conductive members

209

held at the two lower end portions of the lever holder

208

are brought into contact with the rear end face

203

d

of the one-way clutch

203

and receive the return force of the pinion gear

204

. Accordingly, sliding friction is produced between the low heat conductive members

209

and the rear end face

203

d

of the one-way clutch

203

.

According to this embodiment, heat generated by the sliding friction is less likely to transmit to metal portions of the shift lever

206

(the helical spring

207

and the lever holder

208

). As a result, even when the leaf spring

207

made of metal is used as the drive spring, permanent set in fatigue of the leaf spring

207

caused by influence of heat can be restrained and a deterioration in the spring function can be prevented. Particularly, when the engine rotational number in starting is increased by promotion of the ignitability, the return force of the pinion gear

204

received by the shift lever

206

is increased, friction heat generated by the sliding friction is also increased. Therefore, an effect of providing the low heat conductive members

209

at the end portions of the lever is also increased.

Further, since permanent set in fatigue of the leaf spring

207

by heat can be reduced, an effect of using the leaf spring

207

(capable of shortening the shaft length of the starter) can be achieved and a starter which is small-sized and having stable service life can be provided.

(Modification of Second Embodiment)

The shift lever

206

may be applied to a starter having a structure in which the one-way clutch

203

is arranged on the rear side of the shift lever

206

and the pinion gear

204

is moved on the output shaft

201

by itself. Further, the shift lever

206

may be constructed with a single or a plurality of the leaf springs

207

, and the low heat conductive members

209

are provided at end portions of the leaf spring

207

.

(Third Embodiment)

In a third embodiment, as shown in

FIG. 12

, a starter

301

is constructed to include a starter motor

302

for generating rotational force by receiving electricity conduction, an output shaft

303

arranged coaxially with a rotating shaft of the starter motor

302

, a movable cylindrical body

304

fitted to a helical spline

303

a

of the output shaft

303

and movable forward and rearward in an axial direction along the helical spline

303

a

, a restricting member

305

for kicking out the movable cylindrical body

304

to advance by a predetermined amount by bringing a pinion gear

304

a

in mesh with a ring gear

300

while restricting the movable cylindrical body

304

from retreating in order to bring a teeth portion (pinion gear)

304

a

of the movable cylindrical body

304

in mesh with the ring gear

300

of the engine, and drive unit

306

for pushing out a lever

352

of the restricting member

305

in a direction to a side of the movable cylindrical body

304

. The lever

352

is used to generate a spring force.

The starter motor

302

is a direct current motor constructed to include an armature

321

, a fixed electromagnetic pole

322

, a yoke

323

and a brush

324

. When a key switch (starter switch not shown) is turned on and an inner contact (not shown) of the electromagnetic switch

306

is closed, electric power is fed to the armature

321

via the brush

324

and the armature

321

is rotated.

Further, the starter

301

is provided with a speed reduction device

325

for transmitting rotational force of the starter motor

302

to the output shaft

303

. The speed reduction device

325

is constructed with a sun gear

325

a

forming outer teeth at an outer periphery of an armature shaft

321

a

, an internal gear

325

b

in a ring-like shape forming inner teeth in a diametric direction of the sun gear

325

a

and planetary gears

325

c

arranged between the sun gear

325

a

and the internal gear

325

b

to be in mesh with the two gears

325

a

and

325

b

and by revolving the planetary gears

325

c

while being rotated at an outer periphery of the sun gear

325

a

, revolution of the planetary gears

325

c

is transmitted to the outer shaft

303

via pins

325

d

. The speed reduction device

325

is contained along with the armature

321

by the yoke

323

and a center case

326

and an end cover

327

arranged and fixed on a front side and a rear side of the yoke

323

.

The movable cylindrical body (pinion gear)

304

is constructed with including the pinion gear

304

a

to be in mesh with the ring gear

300

of the engine and a one-way clutch

304

b

fitted to the helical spline

303

a

of the output shaft

303

and movable forward and rearward in the axial direction along the helical spline

303

a.

That is, the one-way clutch

304

b

is provided movably in the forward and rearward direction on the output shaft

303

integrally with the cylindrical movable body

304

by being helical spline-fitted to the outer periphery of the output shaft

303

slidably via the helical spline

303

a

. The pinion gear

304

a

is fitted slidably to the outer periphery of the output shaft

303

via a bearing

304

a

1

, move forward on the output shaft

303

integrally with the one-way clutch

304

b

via the lever

352

and brought in mesh with the ring gear

300

to thereby transmit rotational force to the ring gear

300

. Meanwhile, the one-way clutch

304

b

transmits rotation of the output shaft

303

to the pinion gear

304

a

and blocks power transmission between the output shaft

303

and the pinion gear

304

a

when rotational speed of the pinion gear

304

a

exceeds rotational speed of the output shaft

303

by starting the engine.

The restricting member (shift lever device)

305

is constructed with a support portion

351

, the lever

352

supported by the support portion

351

and having a leaf spring

352

a

and a pin

352

c

supported by the support portion

351

for pivoting the lever

352

. In the shift lever device

305

, one side of the lever

352

is arranged to be capable of transmitting reciprocal movement of a movable portion

306

a

in the axial direction to the cylindrical movable body

304

by being brought into contact with the movable portion

306

a

of the drive unit

306

with the support portion

351

as a fulcrum and other side thereof is arranged to be capable of moving to a contact face

304

b

1

of the cylindrical movable body

304

with the support portion

351

as a fulcrum by operating the drive unit

306

when the engine is started. Further, as shown in

FIG. 12

, the shift lever device

305

is contained in a front cover

307

and incorporated in the starter

301

along with the drive unit

306

, the starter motor

302

and the output shaft

303

rotated integrally with the starter motor

302

.

The driving device (electromagnetic switch)

306

is constructed with including a plunger

361

, a coil

362

and an inner contact (not shown). The plunger

361

is provided with a return spring

363

for urging the plunger

361

to a side of the lever

352

when electricity is not conducted to the coil

362

. When the electromagnetic switch

306

is brought into an operating state, that is, when electricity is conducted to the coil

362

and attraction force is generated, the built-in plunger

361

is moved in the right direction of FIG.

12

. In accordance with movement of the plunger

361

, the inner contact is opened and closed, the movable portion

306

a

capable of being brought into contact with the lever

352

of the shift lever device

305

is moved in the forward and rearward direction (left and right direction in

FIG. 12

) integrally with the plunger

361

to thereby move the cylindrical movable body

304

in the forward and the rearward direction (left and right direction in

FIG. 12

) on the output shaft

303

via the lever

352

.

Further, the movable portion

306

a

is provided at a front end of the plunger

361

on the side of the lever

352

. Further, the plunger

361

is provided with a contact spring

364

for applying set load to a movable cylindrical body contact (not shown) of the inner contact for movably arranging a plunger end portion

361

b

in the axial direction.

In this embodiment, when electricity is conducted to the coil

362

built in the electromagnetic switch

306

by operation of turning on the key switch (starter switch), the plunger

361

is attracted in the right direction in FIG.

12

. The movable portion

306

a

is brought into contact with the lever

352

supported by the support portion

351

of the shift lever device

305

and moves the cylindrical movable body

304

by a predetermined amount in accordance with an amount of moving the plunger

361

. That is, when the electromagnetic switch

306

is operated, the pinion gear

304

a

is moved forward on the output shaft

303

integrally with the one-way clutch

304

b

via the lever

352

. Thereby, the cylindrical movable body

304

advances and is brought into contact with the ring gear

300

.

Next, by contacting the pinion gear

304

a

to the ring gear

300

, the plunger is moved further in the right direction and closes the inner contact of the drive unit

306

via the lever

352

. When the inner contact is closed, the armature

321

is conducted with electricity and rotated and rotation of the armature

321

is decelerated by the speed reduction device

325

and is transmitted to the output shaft

303

.

Rotation of the output shaft

303

is transmitted to the pinion gear

304

a

in contact with the ring gear

300

. When the pinion gear

304

a

is rotated up to a rotational angular position capable of being brought in mesh with the ring gear

300

, the pinion gear

304

a

is moved forward impulsively by spring force of the leaf spring

352

a

held in the lever

352

. Accordingly, the pinion gear

304

a

can be brought into mesh with the ring gear

300

. Thereby, rotation of the pinion gear

304

a

is transmitted to the ring gear

300

to thereby start the engine.

Next, after starting the engine, when electricity conduction to the coil

362

of the electromagnetic switch

306

is stopped by operation of turning off the key switch, the plunger

361

which has been attracted, returns to an initial position by urge force of the return spring

363

. Thereby, the lever

352

regresses in the right direction in FIG.

13

. At this occasion, the pinion gear

304

a

is brought into a state of being detachable from the ring gear

300

since nothing restricts regression thereof. Therefore, by operation of the one-way clutch

304

b

, the pinion gear

304

a

is detached from the ring gear

300

integrally with the one-way clutch

304

b

and retreats on the output shaft

303

. Further, by opening the inner contact of the electromagnetic switch

306

, electricity conduction to the armature

321

is stopped to thereby stop rotation thereof.

As shown in

FIG. 13A

, the shift lever device

305

is constructed with the support portion

351

, and the lever

352

supported by the support portion

351

and having the leaf spring

352

a

. The lever

352

is constructed with the leaf spring

352

a

, a lever holder

352

b

for holding the leaf spring and a pin

352

c

for pinching the leaf spring

352

a

along with the lever holder

352

b

. The shift lever

352

operates as a spring force generating member S.

The lever holder

352

b

is formed by a metallic material, and provided with rib portions

352

b

R extended in the axial direction of the starter

301

to surround the leaf spring

352

a

. That is, the lever holder

352

b

is formed by a metallic material and is provided with the rib portions

352

b

R for containing the leaf spring

352

a.

As shown in

FIG. 13B

, to restrict rotation of the pinion gear

304

a

, one side of the lever holder

352

b

on the side of the pinion gear

304

a

is provided with bifurcated portions

352

b

F having two pieces of contact portions

352

d

, which are brought into contact with an outer peripheral side of the contact face

304

b

1

of the pinion gear

304

a

and formed to divide in a bifurcated shape. Further, as shown in

FIG. 13B

, other side thereof on the side of the electromagnetic switch

306

, is provided with a notched portion

352

K such that the movable portion

306

a

of the electromagnetic switch

306

and the leaf spring

352

a

can be brought into contact with each other.

When the pinion gear

304

a

is stationary, that is, before the electromagnetic switch

306

moves the shift lever device

305

to the pinion gear

304

a

, rib portions (corner portions)

352

b

T forming the notched portion

352

K, are brought into contact with the plunger

361

such that the leaf spring

352

a

, that is, a contact portion

352

a

T is not brought into contact with the movable portion

306

a

. Therefore, the leaf spring

352

a

is released in bringing the pinion gear

304

a

in mesh with the ring gear

300

, or when the movable portion

306

a

returns after bringing the pinion gear

304

a

in mesh with the ring gear

300

, load applied on the leaf spring, or impact load can be restrained and received by the corner portions

352

b

T of the lever holder

352

b

. Thereby, breakage of the shift lever device

305

, particularly, the leaf spring

352

a

by the impact load can be prevented.

The leaf spring

352

a

is formed by a spring member and an outer shape thereof is formed to align with the rib portions

352

b

R containing the leaf spring

352

a

of the lever holder

352

b

and is provided with bifurcated portions

352

a

F in correspondence with the bifurcated portions

352

b

F of the lever holder

352

b.

Further, as shown in

FIG. 13A

, it is preferable to form the contact portion

352

a

T in contact with the movable portion

306

a

by bending a leaf spring. Thereby, the contact portion

352

a

T of the leaf spring

352

a

is less likely to be brought into partial contact with a contact face of the movable portion

306

a

of the electromagnetic switch

306

. Accordingly, when the movable portion

306

a

is moved in the right direction in

FIG. 12

by operating the electromagnetic switch

306

, the movable portion

306

a

can advance stably and smoothly toward the pinion gear

304

a

of the lever

352

to be engaged with the movable portion

306

a

. Further, face contact can be carried out by the bent contact portion

352

a

T. Accordingly, the movable portion

306

a

and the contact portion

352

a

T can achieve promotion of reliability in the wear resistance.

The pin

352

c

is formed as a supporting member of a metallic material, arranged in a direction orthogonal to the output shaft

303

and is fixed to the lever holder

352

b

to penetrate the rib portions

352

b

R of the lever holder

352

b

. Pin end portions

352

c

1

projected from the lever holder

352

b

are supported by the support portion

351

as fulcrums of the lever

352

. Thereby, the pin

352

c

is supported by the support portion

351

, makes the lever

352

pivotable and pinches the leaf spring

352

a

by the pin

352

c

and the lever holder

352

b

. The leaf spring

352

a

can be provided with set load. That is, by using the pin

352

c

constituting an operating member for applying set load to the leaf spring

352

a

, the pin

352

c

also serves as the pin end portions

352

c

1

supported by the support portion

351

. Accordingly, the construction can be simplified and downsizing of the starter

301

, particularly, downsizing of the lever

352

can be carried out. The support portion

351

is formed by a resin member and supports the lever

352

constructed as described above with the pin

352

c

as the fulcrum.

When the lever holder

352

b

and the pin

352

c

for applying set load to the leaf spring

352

a

are subjected to material improvement or surface hardening by heat treatment, an increase in strength thereof can be achieved without enlarging configuration thereof. Therefore, a range of setting the set load to the leaf spring

352

a

can be enlarged. That is, the lever holder

352

b

and the pin

352

c

are formed by a metallic material. Accordingly, increase of strength by heat treatment can be carried out to provide desired set load. Therefore, it is not necessary to select means for enlarging configurations of the lever holder

352

b

and the pin

352

c

for increasing strength. Therefore, the configuration can be downsized in comparison with a material which cannot adopt means for increasing strength by material improvement or surface hardening by heat treatment as in a resin material.

Further, as means for fixing the pin

352

c

to the lever holder

352

b

, without using a bonding member of welding, the pin

352

c

can firmly be fixed by press-fitting the pin

352

c

into through holes

352

bc

of the lever holder

352

b.

Further, the leaf spring

352

a

of the lever

352

is provided with the bifurcated portions

352

a

F. Thereby, the leaf spring

352

a

can be prolonged. When set load is applied to the leaf spring

352

a

, an amount of deformation produced by applying load can be increased in accordance with the length. That is, the pin

352

c

for applying set load to the leaf spring

352

a

can be made to be easy to pinch the leaf spring

352

a.

An explanation will be given of a characteristic of promoting performance of bringing the pinion gear

304

a

and the ring gear

300

in mesh with each other by impulsively kicking the pinion gear

304

a

by using spring force of set load of the lever

352

by the shift lever device

305

.

FIG. 14A

is a schematic sectional view showing states of the lever

352

in which electromagnetic switch

306

is in an OFF state.

FIG. 14B

is a schematic sectional view showing a state of the lever

352

in which the electromagnetic switch

306

is in the ON state.

As shown in

FIG. 14A

, in the state in which the electromagnetic switch

306

is not operated, the lever

352

supported by the support portion

351

is arranged vertically with the pin

352

c

as a fulcrum. Since the leaf spring

352

a

is applied with set load, it is not necessary to bend the leaf spring

352

a

by bringing the movable portion

306

a

into contact with the leaf spring

352

a

of the lever

352

. Therefore, it is not necessary to bring the leaf spring

352

a

, that is, the lever

352

into contact with the movable portion

306

a

and the lever

352

may be brought into contact therewith or may be disposed in the vicinity of the movable portion

306

a

without being brought into contact therewith.

When the key switch is brought into the ON state, that is, the electromagnetic switch

306

is brought into the ON state, as shown in

FIG. 14B

, the electromagnetic switch

306

is brought into an operating state. That is, the movable portion

306

a

is moved in the right direction integrally with the plunger

361

from a state of

FIG. 14A

to a state of FIG.

14

B. At this occasion, the contact portion

352

a

T of the leaf spring

352

a

contained in the lever

352

of the shift lever device

305

, is brought into contact with the movable portion

306

a

. When the movable portion

306

a

is further moved in the right direction, the contact portions

352

d

of the lever

352

supported by the support portion

351

are moved by a predetermined amount to the side of the contact face

304

b

1

of the pinion gear

304

a

in accordance with an amount of moving the movable portion

306

a

. The contact portion

352

d

is brought into contact with the contact face

304

b

1

and moves forward and makes the pinion gear

304

a

of the cylindrical body

304

advance to be brought into contact with the ring gear

300

. That is, the pinion gear

304

a

is moved forward on the output shaft

303

and is brought into contact with the ring gear

300

.

When the pinion gear

304

a

moves forward via the lever

352

and comes into contact with the ring gear

300

, the movable portion

306

a

with which the contact portions

352

d

formed at the leaf spring

352

a

of the lever

352

are brought into contact, that is, the plunger

361

moves further in the right direction against set load of the lever

352

and closes the inner contact of the electromagnetic switch

306

.

Further, when the inner contact is closed, the armature

321

is conducted with electricity and rotated and rotation of the armature

321

is decelerated by the speed reduction device

325

and is transmitted to the output shaft

303

. Rotation of the output shaft

303

is transmitted to the pinion gear

304

a

in contact with the ring gear

300

. At this occasion, as shown in

FIG. 14B

, the pinion gear

304

a

is applied with spring force in correspondence with load added with set load of the leaf spring

352

a

of the lever

352

which is detached from a set load operating point

352

S of the lever holder

352

b

and is further bent, and load of a set amount. Therefore, when the pinion gear

304

a

is rotated up to a rotational angular position capable of being brought in mesh with the ring gear

300

, the pinion gear

304

a

is moved forward impulsively in the left direction of

FIG. 14B

by the spring force in correspondence with the load added with the set load and the load of the bent amount.

That is, by operating the electromagnetic switch

306

, the pinion gear

304

a

can be move forward impulsively by the spring force of the lever

352

, that is, the shift lever device

305

provided with the spring force in correspondence with the load added with the load of the bent amount by which the lever

352

in contact with the movable portion

306

a

is detached from the load operating point

352

S and bent in accordance with the predetermined amount of moving until the lever

352

contacting with the movable portion

306

b

brings the pinion gear

304

into contact with the ring gear

300

, and the set load. Thereby, the performance of bringing the pinion gear

304

a

in mesh with the ring gear

300

can be promoted. Therefore, the pinion gear

304

a

and the ring gear

300

are brought in mesh with each other without being brought into mesh with each other insufficiently and the engine can be started swiftly.

Further, as urging means for moving the plunger

361

further in the right direction after the pinion gear

304

a

has been brought into contact with the ring gear

300

and closing the inner contact of the electromagnetic switch

306

, by using the set load of the lever

352

, it is not necessary to include urging means (drive spring) for urging the plunger

361

arranged in the plunger

361

in the right direction. Accordingly, as shown in

FIG. 12

, the plunger

361

can be formed in a cylindrical shape which is not hollow. Therefore, by using the lever

352

having the set load of the leaf spring

352

a

, downsizing of the plunger

361

of the electromagnetic switch

306

, that is, downsizing of the starter

301

can be carried out.

(Modification of Third Embodiment)

As shown in

FIG. 15A

, the leaf spring

352

a

is layered with a plurality of spring members (layered with two sheets of spring members in FIG.

15

A), and the contact portion

352

a

T in contact with the movable portion

306

a

of the electromagnetic switch

306

is formed by bending a spring member

352

a

1

in two sheets of spring members

352

a

1

and

352

a

2

. Thereby, the spring characteristic of the leaf spring

352

a

can be adjusted by combining to select plate thickness of the spring members

352

a

1

and

352

a

2

. Therefore, there can be suppressed a dispersion in respective products of the spring force of impulsively kicking the pinion gear

304

a

. Therefore, desired spring force can be set and the performance of bringing the pinion gear

304

a

and the ring gear

300

in mesh with each other can further be promoted.

The contact portion

352

a

T in contact with the electromagnetic switch

306

of the leaf spring

352

a

is formed by bending one sheet of the spring member

352

a

1

in the leaf spring layered with the spring members

352

a

1

and

352

a

2

. Accordingly, it is easy to bend the contact portion

352

a

T by press-forming and fabrication cost can be reduced. Therefore, stability of operation of advancing the lever

352

of the pinion gear

304

a

by using the electromagnetic switch

306

as well as promotion of reliability of wear resistance of the movable portion

306

a

of the electromagnetic switch

306

and the contact portion

352

a

T of the lever

352

.

Further, as shown in

FIG. 15B

, the leaf spring

352

a

is provided with projected portions

352

a

K locked by notched portions

352

b

K of the lever holder

352

b

. Accordingly, an integration operation of applying set load to the leaf spring

352

a

by pinching the leaf spring

352

a

by the lever holder

352

b

and the pin

352

c

, the leaf spring

352

a

and the lever holder

352

b

are less likely to shift from each other. Thus, the integration operation of integrating the pin

352

c

to the lever holder

352

b

can be facilitated. Further, it is preferable to provide the projected portions

352

a

K at front ends of the bifurcated portions

352

a

F as shown in FIG.

15

B.

The contact portion (brake shoe portion)

352

d

in contact with the contact face

304

b

1

of the pinion gear

304

a

is formed by a resin member and may be fixed to the lever holder

352

b

formed by a metallic material. Therefore, there is a case in which the pinion gear

304

a

is excessively rotated when the pinion gear

304

a

continues to be driven by the engine at an instance of starting the engine after the pinion gear

304

a

of has been kicked impulsively and brought in mesh with the ring gear

300

. However, even when the pinion gear

304

a

is rotated excessively, the lever

352

is brought into contact with the pinion gear

304

a

via the brake shoe portions

352

d

formed by a resin material. Accordingly, owing to heat conductivity of the resin material, heat conduction to the lever holder

352

b

containing the leaf spring

352

a

can be alleviated.

As shown in

FIG. 15A

, a packing

353

formed by a rubber member is provided on a surface of a rear face portion

351

a

fixed to the electromagnetic switch

306

and the starter motor

302

(center case

326

). Thereby, a match face of the electromagnetic switch

306

and the starter motor

302

can be sealed by using the packing. Therefore, invasion of water or oil into an inner space of the starter including the shift lever device

305

can be prevented. Further, the packing

353

is provided with a projected wall

353

a

inserted into and fixed by a positioning hole

351

a

H of the rear face portion

351

. Thereby, promotion of disassembling and assembling operational performance and a reduction in a cost of a spare part in the market are compatible.

Further, as shown in

FIG. 15B

, corner portions

352

b

T are provided on the side of the electromagnetic switch of the lever holder

352

b

of the lever

352

. Therefore, the lever holder

352

b

can be projected to be longer than the leaf spring

352

a

in a direction orthogonal to the shaft of the pin

352

c.

Thereby, the corner portions

352

b

T can be brought into contact with the plunger

361

such that the contact portion

352

a

T of the leaf spring

352

a

is not brought into contact with the movable portion

306

a

when the pinion gear

304

a

is stationary. Therefore, when the pinion gear

304

a

is brought in mesh with the ring gear

300

or after the pinion gear

304

a

has been in mesh therewith, impact load applied on the leaf spring can be restrained and can be received by the corner portion

352

b

T.

Further, it is preferable that the corner portion is provided with an end portion shape

352

b

TC capable of being brought into face contact with the plunger

361

constituting the driving device regardless of attitude, that is, inclination of the lever holder

352

b

. The end portion shape

352

b

TC may be a curved shape of R shape as shown in

FIG. 15A

to thereby carry out the face contact.

Further, other than the construction of the shift lever device

305

for applying set load to the leaf spring

352

a

explained in the embodiment, in which the shift lever device

305

is constructed with the apparatus of including the leaf spring

352

a

and the lever holder

352

b

for holding the leaf spring

352

a

, there may be constructed any construction of the shift lever device for only holding the leaf spring without applying the set load so far as the performance of bringing the pinion gear and the ring gear in mesh with each other is improved by utilizing spring force by the leaf spring.

The above modification of the second embodiment has the shift preventive structure of the leaf spring

352

a

and the structure of preventing breakage of the leaf spring

352

a

by excessive load in the lever

352

constituting the spring force generating apparatus S.

When the projected end portion

352

a

K does not catch the lever holder

352

b

by bending thereof but as shown in

FIG. 15A

, formed on a developed plane of the leaf spring

352

a

, there can be constructed a construction in which stress concentration is less likely to operate at the projected end portion

352

a

K even when the notched portion

352

b

K of the lever holder

352

b

is caught thereby.

Further, as shown in

FIG. 15B

, it is preferable that the projected portion

352

a

K is provided at a front end of at the bifurcated portion

352

a

F. Thereby, according to the lever

352

constituting the spring force generating apparatus S, load can be absorbed in accordance with a length to the projected portion

352

a

K constituting the end portion of the leaf spring

352

a.

Next, as shown in

FIG. 15A

, the pin

352

c

constituting the support member is formed in a cylindrical shape. Accordingly, movement of an operating point for applying set load to the leaf spring

352

a

can be made smaller than in a polygonal shape such as a rectangular shape. Accordingly, excessive load accompanied by moving the leaf spring

352

a

can be made less likely to occur at the end portion

352

a

K.

Further, it is preferable to set to arrange the end portion

352

a

K as follows in relation to the pin

352

c

constituting the support member. That is, a distance of separating the pin

352

c

and the end portion

352

a

K is set to be larger than a movement amount for moving the leaf spring

352

a

owing to deformation thereof. Thereby, interference of the end portion

352

a

K with the pin

352

c

by deforming the leaf spring

352

a

can be avoided. Accordingly, excessive load can be prevented from being loaded on the leaf spring

352

a.

According to the brake shoe portion

352

d

, as shown in

FIG. 15B

, it is preferable to provide a guide portion

352

d

G for guiding the end portion

352

a

K of the leaf spring

352

a

. Thereby, when the end portion

352

a

K is fixed by catching the lever holder

352

b

, performance of settling the end portion

352

a

K is promoted. Accordingly, positioning of the leaf spring

352

a

is facilitated.

The present invention should not be limited to the disclosed embodiments and modifications, but may be implemented in various ways without departing from the spirit of the invention.

Number	Date	Country
2000-007835	Jan 2000	JP
2000-273953	Sep 2000	JP
2000-325479	Oct 2000	JP
2000-351440	Nov 2000	JP

Number	Name	Date	Kind
3177728	Farison	Apr 1965	A
3283595	Masanori	Nov 1966	A
3788151	Campau	Jan 1974	A
3955427	Squires	May 1976	A
4296342	Young et al.	Oct 1981	A
4353449	Lamy et al.	Oct 1982	A
4579010	Colvin et al.	Apr 1986	A
4779470	Morita et al.	Oct 1988	A
4958097	Woodward et al.	Sep 1990	A
5222401	Fasola et al.	Jun 1993	A
5341697	Isozumi	Aug 1994	A
6202497	Kuragaki et al.	Mar 2001	B1

Number	Date	Country
0 349 281	Jan 1990	EP
0 425 158	May 1991	EP
2 423 650	Nov 1979	FR
1 519 950	Aug 1978	GB
2 180 889	Apr 1987	GB
56-70156	Nov 1954	JP
54-1512724	Dec 1979	JP
8-8040	Jan 1996	JP

Starter having resilient shift lever for driving pinion gear

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Term Extension

Abstract

Description

Claims

Priority Claims (4)

US Referenced Citations (12)

Foreign Referenced Citations (8)

Non-Patent Literature Citations (3)

Entry
Journal of Nippondenso Technical Disclosure No. 57-057.
Journal of Nippondenso Technical Disclosure No. 55-043.
Journal of Nippondenso Technical Disclosure No. 55-036.