DE102006006563B4 - Starter of the design with constant engagement - Google Patents

Abstract

Constant engagement type starter comprising: a starter motor generating a torque at its armature shaft when supplied with electric power; an output shaft coupled to the armature shaft; a pinion provided on this output shaft and always engaged with a gear on the side of an internal combustion engine and a counter rotation preventing clutch configured to allow the armature shaft to rotate in the normal direction to the internal combustion engine in the normal direction, and prevents the armature shaft from rotating in the reverse direction when counteracting the output shaft with an opposing torque transmitted from the counter-rotating internal combustion engine, the armature shaft and the output shaft with each other coupled by a speed reducer configured to transmit a rotational movement of the armature shaft to the output shaft while reducing the rotational speed of this rotational movement, the clutch being provided for preventing counterrotating rotation on the armature shaft and configured i that is, it prevents the armature shaft from rotating in the opposite direction when the counter torque is transmitted to the clutch for preventing reverse rotation by the speed reducing device.

Description

BACKGROUND OF THE INVENTION

1. Technical field of the invention

The present invention relates to a constant-contact type starter applicable to automobiles.

2. Description of the Related Art

A constant engagement type starter makes it possible to restart the engine before the engine is stopped completely, because a pinion of the starter is constantly engaged with a ring gear of the engine directly or indirectly via an intermediate gear or the like, as disclosed in US Pat Japanese Patent Application No. JP 2004-225 544 A is described. In addition, a vehicle provided with a constant-engagement type starter is quiet in comparison with a vehicle provided with a conventional electromagnetic feed type starter designed such that when starting an engine, its pinion is in an engaged position with an engine motor-side ring gear is pressed because no locking noise between the pinion and the ring gear occur.

In the constant engagement type starter, when the engine performs a full stroke, as a result of which the engine rotational speed exceeds that of the starter, the pinion is driven by the ring gear. At this time, an armature of a starter motor may be forced to rotate at a high speed equal to the engine speed multiplied by the gear ratio between the ring gear and the pinion (generally 8 to 15), and further with the speed reduction ratio of an internal speed reduction device. if it is included in the starter. As a result, the armature can be destroyed by the centrifugal force. To avoid this, such a constant engagement type starter is provided with an overrunning clutch configured to idle when the engine speed is higher than that of the starter.

However, the overrunning clutch is unable to block torque transmission from the engine to the starter when the engine is running in the opposite direction, that is, when the engine is running and the crankshaft is rotating in the opposite direction because the overrunning clutch engages the ring gear with the engine Pinion engages when the engine is running in the opposite direction. Accordingly, there is a possibility that the armature is forced to rotate at a high speed and thereby be destroyed when the engine rotates in the opposite direction.

The reverse rotation of the internal combustion engine may occur during the period in which the engine is stopped, because when stopping the internal combustion engine, the reciprocating movements of the pistons of the internal combustion engine, before they reach stable stop positions in the cylinders, in the rotational movement of the Crankshaft may cause a fluctuation between the normal direction and the opposite direction. Although the overrunning clutch may block torque transfer from the engine to the starter as the crankshaft rotates in the normal direction, it can not block torque transfer from the engine to the starter as the crankshaft rotates in the opposite direction.

Therefore, the armature located behind the overrunning clutch seen from the engine side can be forced to rotate in the opposite direction by the fluctuation in the rotational movement of the crankshaft. If the opposing movement of the armature occurs every time when stopping the internal combustion engine, the life of the brushes of the starter motor is shortened. In addition, the noise caused by the grinding of the brushes via the commutator of the starter motor is uncomfortable to the driver.

The reverse rotation of the crankshaft may also occur when a vehicle is strangled on a rising road. If a vehicle whose gearshift lever is in any forward drive associated drive position is strangled on a slope and starts to move backwards, an opposite torque is transmitted from the wheels to the engine, as a result, the crankshaft in the opposite direction rotates. This opposite torque is transmitted through the overrunning clutch on the starter and as a result, the armature is rotated in the opposite direction. The reverse rotation of the starter motor armature continues until a driver of the vehicle depresses a brake pedal or a clutch pedal.

Further relevant prior art can be found in AT 99 819 B such as JP S63-277 859 A , Especially AT 99 819 B discloses a starting device for motor vehicles, characterized in that two freewheel devices are provided, one of which prevents the reverse rotation of the internal combustion engine and the Andrehmotors in which rests against a fixed housing or frame part.

BRIEF DESCRIPTION OF THE INVENTION

The present invention provides a constant engagement type starter comprising:
a starter motor generating a torque at its armature shaft when supplied with electric power;
an output shaft coupled to the armature shaft;
a provided on this output shaft and always with a gear on the side of an internal combustion engine engaged pinion and
a reverse rotation preventing clutch configured to allow the armature shaft to rotate in the normal direction to make the engine rotate in the normal direction and prevent the armature shaft from rotating in the opposite direction; When the output shaft is subjected to an opposite torque, which is transmitted from the rotating in the opposite direction of the internal combustion engine.

With the present invention, it becomes possible to prevent the armature of a starter motor of a constant engagement type starter from being counteracted under the effect of a fluctuation in the rotational motion of the crankshaft of the vehicle engine during the period in which the engine is stopped Turning torque or by the reverse movement of the stalled vehicle at high speed in the opposite direction. With the present invention, damage to the armature and reduction in the life of a brush of the starter motor can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

From the attached drawings

1 a view, half in longitudinal section, of a constant-engagement type starter according to an embodiment of the present invention

2 a part of a longitudinal section of the constant-engagement type starter showing the construction of a speed-reducing device and a counter-rotation preventing clutch associated therewith;

3 a portion of a cross section of the coupling for preventing an opposite rotation, of which one of its cam chambers is visible;

4 a cross section through the clutch for preventing an opposite rotation in a state when starting the internal combustion engine and

5 a cross section through the clutch for preventing an opposite rotation in a state in which the internal combustion engine rotates in the opposite direction.

PREFERRED EMBODIMENTS OF THE INVENTION

The 1 is a view, half as a longitudinal section, of a starter 1 Constant-engagement type according to an embodiment of the present invention.

The ignition 1 closes a starter motor 3 one at his anchor 2 generates a torque, as well as an electromagnetic relay 4 for opening and closing a main contact of a (not shown) power supply circuit of the starter motor 3 , a speed reducing device 8th to reduce the speed of the armature 2 and their transmission to an output shaft 5 , a pinion carried by the output shaft 7 and a clutch 8th to prevent an inverse rotation affecting the anchor 2 prevents it from being turned in a direction in which the anchor 2 when starting an internal combustion engine rotates.

The electric motor 3 includes a field generator consisting of a plurality of permanent magnets 10 at regular intervals on an inner circumference of a yoke 9 are attached and form a magnetic circuit, as well as the inside of the yoke 9 rotatable built-in anchor 2 and a brush 12 in sliding contact with one in the anchor 2 provided commutator 11 stands. When the main contact through the electromagnetic relay 4 is closed, the electric motor 3 supplied with electric power from a vehicle battery (not shown), thereby at the armature 2 to generate a torque. The permanent magnets 10 can be replaced by a field coil. The electromagnetic relay 4 includes a solenoid that generates an electromagnetic force when supplied with a current from the vehicle battery to close the main contact.

As in 2 As shown, the speed reducing device is a sun gear 14 formed at one end of a rotatable shaft 13 of the anchor 2 (hereinafter referred to as "armature shaft") is formed, a ring gear 15 its rotation by a shock absorbing device 18 is limited, and a plurality of planetary gears 16 that with the sun wheel 14 and the ring gear 15 engage. If the anchor 2 rotated at a state in which the ring gear 15 is prevented from its rotation, the rotation of the armature 2 through the sun wheel 14 on the planet wheels 16 transmitted, causing the planet gears 16 around the sun wheel 14 move. The orbital motion the planet wheels 16 will be on the output shaft 5 through trunnions 17 transferred, on which the planet gears are rotatably mounted.

As in 2 is shown, the shock absorbing device 18 from a solid disk 21 formed, fixed to a middle part of the housing 20 is attached, one between the middle part of the housing 20 and the solid disc 21 inserted rotatable, with the ring gear 15 the speed reduction device 6 engaged disc 22 and a plate spring 23 holding the rotatable disc 22 over the solid disc 21 in the direction of the middle part of the housing 20 biases. The rotatable disc 22 is due to friction with the solid disc 22 and the middle part of the housing 20 , which serve as a friction disc, prevented from rotating. When an excessive torque, greater than a holding torque of the rotating disc 22 , on the ring gear 15 is exercised, the ring gear 15 allowed to rotate because of the rotatable disc 22 against the friction with the solid disc 21 and the middle part of the housing 20 twisted so that the excessive torque is absorbed.

The output shaft 5 coaxial with the armature shaft 13 is arranged, is rotatable by a front housing part 19 about a camp 24 worn at its one end and is with its other end with the armature shaft 13 via the speed reducer 6 connected. The wedge-like with the output shaft 5 connected pinions 7 stands permanently with the sprocket 25 of the internal combustion engine engaged.

The coupling 8th to prevent an opposite movement is from a clutch outer part 26 formed, the fixed between the middle part of the housing 20 and the yoke 9 is arranged, one on the armature shaft 13 provided clutch inner part 27 , Clutch rollers 29 in between the clutch outer 26 and the clutch inner part 27 trained cam chambers 28 (please refer 3 ) and the clutch rollers 29 towards the sections of greater height in the cam chambers 28 biasing springs 30 ,

As in 3 shown is the chamber 28 formed so that it has a wedge-shaped shape such that its height (the distance between the outer circumference of the clutch inner part 27 and the inner circumference of the clutch outer 26 ) decreases gradually in the circumferential direction. As in 3 to see is the height of the cam chamber 28 larger in its right portion and smaller than the diameter of the clutch pulley in the left portion thereof 29 ,

As in 4 shown, the clutch inner rotates 27 in the clockwise direction, as indicated by an arrow in this figure, the clutch roller 29 moves towards the right section, where it can rotate freely, which is why the clutch inner part 27 this rotation can continue.

On the other hand, as in 5 shown when the clutch inner rotates counterclockwise in the direction indicated by an arrow in this figure, the clutch roller 29 towards the left section, where they are between the clutch outer 26 and the clutch inner part 27 is blocked, causing the clutch inner part 27 is prevented from rotating.

The coupling 8th to prevent an inverse rotation is designed so that their clutch rollers 29 turn loosely around the clutch inner part 27 to allow it to rotate in the normal direction, so that the torque of the armature rotating in the normal direction 2 for cranking the internal combustion engine via the speed reduction device 6 on the output shaft 5 is transferred, and that the clutch rollers 29 to prevent rotation of the clutch inner part 27 be blocked in the opposite direction, to prevent a reverse torque from the engine to the armature 2 is transmitted.

Next is the action of the starter 1 explained with the structure explained above. When the main contact of the electric motor 3 through the electromagnetic relay 4 is closed, flows from the vehicle battery, a current in the anchor 2 and that's why at anchor 2 developed a torque. As explained above, the anchor is 2 if it turns in the normal direction, not through the clutch 8th to prevent reverse rotation from rotating in the opposite direction because the clutch rollers 29 to turn loose at this time. As a result, the rotation of the armature becomes 2 through the speed reducing device 6 on the output shaft 5 and for cranking the engine further over the pinion 7 on the sprocket 25 transfer.

When the engine is started, the overrunning clutch (not shown) prevents the transmission of the rotational movement in the normal direction of the crankshaft to the ring gear 25 to thereby rotate the armature 2 to avoid. Of course, upon rotation of the crankshaft in the opposite direction, the clutch will occur 8th to prevent reverse rotation in action to the clutch inner part 27 to prevent rotation and thereby avoid the anchor 2 turns in the opposite direction.

By the present embodiment, it becomes possible to rotate the armature 2 to avoid at high speed in the opposite direction by the effect of fluctuations in the rotational movement of the crankshaft during the period for stopping the internal combustion engine or during reverse rotation of the stopped vehicle. However, with the present embodiment, the damage of the armature 2 and reducing the life of the brushes 12 be prevented.

At the starter 1 This embodiment, the clutch 8th to prevent an opposite rotation, because they are on the armature shaft 13 is provided, as seen from the internal combustion engine after the Drehzahlreduziervorrichtung 6 is arranged, the one from the internal combustion engine to the armature shaft 13 transmitted torque reduced by their small speed reduction ratio, a small torque capacity and consequently a small size compared to the case that the clutch 8th for preventing reverse rotation in front of the speed reducing device 6 is arranged.

Besides, because the starter 1 this embodiment with the shock absorbing device 18 is provided, which has an excessive torque, greater than the holding torque of the rotatable disc 22 and transmitted from the internal combustion engine, absorbed, various, between the sprocket 25 and the output shaft 5 arranged components have lower strengths and smaller designs, without the reliability of the starter 1 to lower.

Because the pinion 7 always with the sprocket 25 is engaged, the starter according to this embodiment is able to quickly restart a vehicle engine and has the additional advantage that it is quiet, because no engagement noise between the pinion 7 and the sprocket 25 occur.

The ignition 1 This embodiment is also able to eliminate the noise that occur so far when stopping the vehicle da9 anchor 2 is caused to rotate in the opposite direction and thereby the brush 12 is initiated via the commutator 11 to delete.

Accordingly, the starter 1 According to this embodiment advantageously be used in a vehicle, which is provided with an automatic system for stopping and restarting the internal combustion engine (also called "ecorun system"), which automatically stops the internal combustion engine of a vehicle when the vehicle at a stop red light or in a traffic jam, and shortly thereafter restart the engine because the frequency of the engine restart is considerably greater compared to the case where the vehicle is not provided with such a system.

In the above-described embodiment, the overrunning clutch, which is configured to be idling when the rotational speed of the engine exceeds that of the starter, may be inside the starter instead of between the crankshaft and the ring gear 25 be provided. For example, she may be in the pinion 7 on the output shaft 5 be integrated.

The pinion 7 Can be integral with the output shaft 5 be formed when the overrunning clutch between the crankshaft and the ring gear 25 is arranged, as is the case in the embodiment, because it is not necessary, the pinion 7 to move in the axial direction of the output shaft, unlike a conventional starter type in which the pinion is pushed electromagnetically into an engaged position with a motor-side ring gear.

The preferred embodiments discussed above are exemplary of the invention according to the present application, which is described solely by the appended claims. It should be understood that modifications of the preferred embodiments can be made as will be apparent to those skilled in the art.

Claims (8)

Constant engagement type starter comprising: a starter motor generating a torque at its armature shaft when supplied with electric power; an output shaft coupled to the armature shaft; a pinion provided on this output shaft and always engaged with a gear on the side of an internal combustion engine and a counter rotation preventing clutch configured to allow the armature shaft to rotate in the normal direction to the internal combustion engine in the normal direction, and prevents the armature shaft from rotating in the reverse direction when counteracting the output shaft with an opposing torque transmitted from the counter-rotating internal combustion engine, the armature shaft and the output shaft with each other are coupled by a speed reducing device which is designed so that it transmits a rotational movement of the armature shaft to the output shaft, while the rotational speed of this Reduces rotational movement, wherein the coupling for preventing an opposite rotational movement on the armature shaft is provided and designed so that it prevents the armature shaft from rotating in the opposite direction, when the opposing torque is transmitted through the speed reduction device to the coupling for preventing an opposite rotational movement. The constant-engagement type starter according to claim 1, wherein the clutch for preventing counterrotating rotation comprises a clutch outer, a clutch inner mounted on the armature shaft and clutch rollers disposed between the fixed clutch outer and clutch inner, and the clutch for preventing counterrotating rotation is that the clutch rollers rotate loosely to allow the clutch inner part to rotate when the armature shaft rotates in the normal direction for cranking the engine, and are locked in a gap between the fixed clutch outer part and the clutch inner part to the clutch inner part at a To prevent rotation, so that the armature shaft is prevented from rotating in the opposite direction under the action of the counter-rotating torque. The constant-engagement type starter according to claim 1, wherein the speed-reducing device is provided with a shock absorbing device for absorbing a larger torque than a predetermined torque transmitted from the engine to the output shaft. The constant-engagement type starter according to claim 2, wherein the speed reducing device is provided with a shock absorbing device for absorbing a larger torque than a predetermined torque transmitted from the engine to the output shaft. The constant-engagement type starter according to claim 3, wherein the speed reducing device includes a sun gear formed at one end of the armature shaft and a ring gear coaxial with this sun gear and a plurality of planetary gears meshing with the sun gear and the ring gear wherein a rotation of the planetary gears caused by the rotation of the armature shaft is transmitted to the output shaft around the sun gear, and wherein the shock absorbing device comprises a rotatable disc coupled to the ring gear and a fixed friction disc which frictionally engages the rotary disc. The constant-contact type starter according to claim 4, wherein the speed reducing device includes a sun gear formed at one end of the armature shaft and a ring gear coaxial with this sun gear and a plurality of planetary gears meshing with the sun gear and the ring gear wherein a rotation of the planetary gears caused by the rotation of the armature shaft is transmitted to the output shaft around the sun gear, and wherein the shock absorbing device comprises a rotatable disc coupled to the ring gear and a fixed friction disc which frictionally engages the rotary disc. The constant engagement type starter according to claim 1, further comprising an overrunning clutch integrally connected to the pinion on the output shaft, the overrunning clutch being configured to permit transmission of torque from the output shaft to the pinion as the rotational speed of the output shaft becomes larger is than the rotational speed of the pinion, and the torque transmission from the pinion to the output shaft blocked when the rotational speed of the pinion is greater than the rotational speed of the output shaft. The constant-engagement type starter according to claim 1, further comprising a power supply circuit that controls the power supply of the starter motor in accordance with a command received from an external automatic system for stopping and restarting the internal combustion engine.

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