FR2882107A1 - Engine starter for motor vehicle, has clutch allowing armature shaft to rotate in normal direction and preventing reverse rotation of armature shaft when output shaft applies reverse torque from motor rotating in reverse direction - Google Patents

Abstract

The starter has an electric motor generating a torque in an armature shaft (13), and an output shaft (5) coupled to the shaft (13). A pinion (7) is disposed on the shaft (5). A clutch allows the shaft (13) to rotate in a normal direction to actuate the motor in the normal direction and prevents a reverse rotation of the shaft (13) when the output shaft applies a reverse torque from the motor rotating in the reverse direction.

Description

PERMANENT GEAR TYPE STARTER

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a permanent engagement type starter that can be used on a vehicle.

  2. Description of the Related Art

  A permanent meshing starter allows a motor to be restarted before the motor is completely shut down, because a starter gear is still meshing with a motor crown directly or through an intermediate gear or the like as disclosed in Japanese Patent Application Laid Open No. 2004-225 544. In addition, a vehicle with the permanent meshing type starter is quiet compared to a vehicle with a push-type starter. conventional electromagnet configured to push its pinion to an engagement position with a motor-side rim when starting the engine, since no meshing noise occurs between the pinion and the rim.

  In the permanent meshing type starter, when an engine starts a complete explosion, as a result of which the engine rotation speed exceeds that of the starter, the gear is driven into the gear. At this time, the armature of the electric starter motor can be forced to rotate at a high speed shifts to the rotational speed of the motor multiplied by a reduction ratio between the crown and pinion (usually 8 to 15), and further by a speed reduction ratio of an internal speed reduction device when included in the starter. As a result, the armature can be broken due to the centrifugal force. To avoid this, such a permanent meshing type starter is provided with a freewheel clutch configured to run idle when the rotational speed of the motor exceeds that of the starter.

  However, the freewheel clutch does not block the transmission of the engine torque to the starter when the engine is operating in the opposite direction, that is to say when the engine is running with its crankshaft which turns in the opposite direction , because the freewheel clutch couples the crown to the pinion when the motor rotates in the opposite direction. Accordingly, there is a possibility that the armature is forced to rotate at a high speed and is therefore broken when the motor rotates in the opposite direction.

  The reverse rotation of an engine may occur during the period when the engine is stopping, because, when the engine is stopping, the reciprocating movements of the pistons of the engine. engine, before they arrive at stable stopping positions, in the cylinders can cause fluctuations between the normal direction and the opposite direction of the crankshaft rotation movement. Although the overrunning clutch can block torque transmission from the engine to the starter when the crankshaft rotates in the normal direction, it can not block torque transmission from the engine to the starter when the crankshaft rotates in the opposite direction.

  Therefore the armature behind the freewheel clutch, when viewed from the engine side, may be forced to rotate in the opposite direction due to the fluctuation of the rotational movement of the crankshaft. If the reverse rotation of the armature occurs each time the motor is stopped, the life of a starter motor motor broom is shortened. In addition, a noise caused by the sliding broom on a collector of the electric starter motor provides a feeling of discomfort to the driver.

  The reverse rotation of the crankshaft can take place also when a vehicle stalls on a road that goes up. If a vehicle, whose gearshift lever is in any forward gear position on an uphill road, and begins to reverse, a reverse torque is transmitted from the wheels to the engine, following which the crankshaft rotates. the opposite direction. This reverse torque is transmitted to the starter via the freewheel clutch, and it follows that the armature is rotated in the opposite direction. Reverse rotation of the electric starter motor armature continues until the vehicle driver presses a brake pedal or clutch pedal.

  SUMMARY OF THE INVENTION The present invention provides a permanent meshing type starter comprising: an electric starter motor generating a torque at an armature shaft thereof when electrically energized; output coupled to the armature shaft, a pinion disposed on the output shaft and always meshing with a gear wheel on the motor side, and a clutch preventing reverse rotation configured to allow the armature shaft to rotate in a normal direction to thereby start a motor in its normal direction, and to prevent the armature shaft from being rotated in the opposite direction when the output shaft is subjected to an inverse torque transmitted by the motor turning in the opposite direction.

  With the present invention, it becomes possible to prevent the armature of a starter motor of a starter of the permanent meshing type from rotating at a high speed in the opposite direction because of the action of the reverse torque. caused by the fluctuation of the rotational movement of the crankshaft of a vehicle engine during the period when the engine is stopping, or by the rearward movement of the vehicle when it has stalled. Thus, with the present invention, the breaking of the armature, and the reduction of the life of a starter motor electric motor brush can be prevented.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings.

  FIG. 1 is a longitudinal cross-sectional view of a permanent meshing type starter according to an embodiment of the invention; FIG. 2 is a partial cross-sectional view of the permanent meshing type starter representing structures of a speed reduction device and its clutch preventing. FIG. 3 is a partial cross-sectional view of the clutch preventing reverse rotation showing a cam chamber thereof; FIG. 4 is a cross-sectional view of the clutch preventing reverse rotation in a state where a motor is started, and FIG. 5 is a cross-sectional view of the clutch 5 preventing reverse rotation in a state where the motor is rotating in a reverse direction.

  PREFERRED EMBODIMENTS OF THE INVENTION

  FIG. 1 is a longitudinal transverse half-sectional view of a permanent-engagement type starter 1 according to one embodiment of the invention.

  The starter 1 comprises an electric starter motor 3 generating a torque at its armature 2, an electromagnetic relay 4 intended to open and close a main contact of a power supply circuit (not shown) of the electric starter motor 3, a speed reduction device 6 for reducing the speed of rotation of the armature 2 and for transmitting it to an output shaft 5, a pinion 7 supported by the output shaft 5, and a clutch preventing reverse rotation 8 intended to prevent the armature 2 is rotated in a direction opposite to the direction in which the armature 2 rotates at the time of starting the engine.

  The electric motor 3 comprises a field generator consisting of a plurality of permanent magnets 10 mounted at regular intervals on an inner periphery of a yoke 9 forming a magnetic circuit, the armature 2 installed with the possibility of rotation inside. of the cylinder head 9, and a brush 12 which is in sliding contact with a manifold 11 disposed in the frame 2. When the main contact is closed by the electromagnetic relay 4, the motor 3 is powered electrically by a vehicle battery (no shown) to thereby generate a torque at the frame 2. The permanent magnets 10 may be replaced by a field coil. The electromagnetic relay 4 comprises an electromagnet that generates an electromagnetic force when it receives a current from the vehicle battery to close the main contact.

  As shown in FIG. 2, the speed reduction device is constituted by a sun gear 14 formed in one end of a rotary shaft 13 of the frame 2 (called "armature shaft" below), a gear annular 15 whose rotation is restricted by a shock absorbing device 18, a plurality of planet gears 16 meshing with the sun gear 14 and the annular gear 15. When the armature 2 turns into a state where the As the ring gear 15 is prevented from rotating, the rotation of the armature 2 is transmitted to the planet gears 16 via the sun gear 14, whereby the planet gears 16 rotate around the sun gear 14. orbital of the planet gears 16 is transmitted to the output shaft 5 by means of a transmission shaft 17 which rotatably supports the planet gears 16.

  As indicated in FIG. 2, the shock absorbing device 18 consists of a fixed disk 21 fixedly installed on a central housing 20, a rotating disk 22 placed between the central housing 20 and the fixed disk 21 and meshing with the annular gear 15 of the speed reduction device 6, and a disc spring 23 urging the rotating disc 22 towards the central housing 20 via the fixed disc 21. The rotating disc 22 is prevented from spinning by friction with the fixed disk 21 and the central housing 20 which serve as a friction plate. When an excessive torque greater than a holding torque of the rotating disc 22 is applied to the annular gear 15, the annular gear 15 is rotatable because the rotating disc 22 rotates in opposition to friction with the fixed disc 21 and the central housing 20, so that excessive torque can be absorbed.

  The output shaft 5, which is arranged coaxially with the armature shaft 13, is rotatably supported by a front housing 19 by means of a bearing 24 at one end thereof, and coupled to the armature shaft 13 via the speed reduction device 6 at its other end. The pinion 7, which is splinedly connected to the output shaft 5, is permanently engaged with the ring gear 26 of the engine.

  The clutch preventing reverse rotation 8 is constituted by an outer clutch portion 26 arranged in a fixed manner between the central housing 20 and the cylinder head 9, an inner clutch portion 27 disposed on the armature shaft 13, clutch rollers 29 disposed in the cam chambers 28 (see Fig. 3) formed between the clutch outer portion 26 and the clutch inner portion 27, and springs 30 biasing the clutch rollers 29 to higher height parts in the cam chambers 28.

  As shown in Fig. 3, the cam chamber 28 is formed to have a wedge-like shape whose height (the gap distance between the outer periphery of the clutch inner portion 27 and the inner periphery of the outer portion clutch 26) progressively decreases along its circumferential direction. The height of the cam chamber 28 is greater than the diameter of the clutch roller 29 at its right-hand portion as seen in FIG. 3, and smaller than the diameter of the clutch roller 29 at the its left side, as seen in Figure 3.

  As shown in Fig. 4, when the inner clutch portion 27 rotates clockwise as shown by an arrow in this figure, the clutch roller 29 moves to the right side where it can rotate. freely, as a result of which the inner clutch portion 27 can continue to rotate.

  On the other hand, as shown in FIG. 5, when the inner clutch portion 27 rotates counterclockwise indicated by an arrow on this figure, the clutch roller 29 moves toward the side portion. left where it is blocked between the outer clutch portion 26 and the inner clutch portion 27, whereby the inner clutch portion 27 is prevented from rotating.

  The reverse rotation preventing clutch 8 is configured such that its clutch rollers 29 turn idle to allow the clutch inner portion 27 to rotate in the normal direction so that the torque of the armature 2 rotates in the opposite direction. the normal direction is transmitted to the output shaft 5 via the speed reduction device 6 to thereby start the engine, and that the clutch rollers 29 are locked to prevent the inner clutch portion 27 from rotating in the opposite direction to prevent a reverse torque from being transmitted from the motor to frame 2.

  Next, the operation of the starter 1 having the structure described above is explained. When the main contact of the electric motor 3 is closed by the electromagnetic relay 4, a current flows in the frame 2 from the vehicle battery, and as a result a torque is developed at the frame 2. As explained above, when the armature 2 rotates in the normal direction, the armature 2 is not prevented from rotating by the clutch preventing a reverse rotation 8, since the clutch rollers 29 turn empty at this time. moment. As a result, the rotation of the armature 2 is transmitted to the output shaft 5 via the speed reduction device 6, and is further transmitted to the ring gear 25 via the pinion 7 to thereby start. engine.

  After the engine is started, the freewheel clutch (not shown) prevents rotation in the normal direction of the crankshaft being transmitted to the ring 25 to thereby prevent the armature 2 from being rotated. Obviously, when the crankshaft rotates in the opposite direction, the clutch preventing reverse rotation 8 acts to prevent the inner clutch portion 27 from being rotated to prevent the frame 2 from being driven. rotating in the opposite direction.

  With the present embodiment, it becomes possible to prevent the armature 2 from being rotated in the opposite direction at a high speed due to the action of the reverse torque caused by the fluctuation of the rotational movement of the crankshaft. during the period when the engine is stopping, or by the rearward movement of the stalled vehicle. Thus, with the present embodiment, the breaking of the frame 2, and the reduction of the life of the blade 12 can be prevented.

  In the starter 1 of this embodiment, as the clutch preventing reverse rotation 8 is disposed on the armature shaft 13 which is arranged, when viewed from the engine side, downstream of the reduction device 6 which reduces a torque that is transmitted from the motor to the armature shaft 13 through its speed reduction ratio, the clutch preventing a reverse rotation 8 may have a low torque capacity and consequently a small structure compared to a case where the clutch preventing reverse rotation 8 is disposed upstream of the speed reduction device 6.

  In addition, since the starter 1 of this embodiment is provided with the shock absorbing device 18 which absorbs excessive torque greater than the holding torque of the rotating disc 22 and transmitted from the engine, various components arranged between the crown 25 and the output shaft 5 may have low resistances and small structures without decreasing the reliability of the starter 1.

  Since the pinion 7 is still in mesh with the ring gear 25, the starter 1 of this embodiment can restart a vehicle engine quickly, and has the added advantage of being quiet because no meshing noise occurs. between pinion 7 and crown 25.

  The starter 1 of this embodiment can also eliminate the noise that occurred previously when the vehicle is stopped by causing the armature 2 to turn in the opposite direction and thereby causing the blade 12 to slide on the manifold 11.

  Accordingly, the starter 1 of this embodiment can be advantageously used in a vehicle equipped with an automatic engine stop / restart system (also referred to as an "idle stop system" or "economical operating system"). ") which automatically stops a vehicle engine when the vehicle is stopped at a red light or by a traffic jam, and automatically restart the engine shortly thereafter, as the frequency of the engine restart is much greater compared to a case where the vehicle is not equipped with such a system.

  In the embodiment described above, the overrunning clutch configures: d to idle when the rotational speed of the motor exceeds that of the starter can be arranged inside a starter instead of being disposed between the crankshaft and the crown 25. For example, it can be made integral with the pinion 7 on the output shaft 5.

  The pinion 7 can be integrally formed with the output shaft 5 when the freewheel clutch is disposed between the crankshaft and the ring 25 as is the case with the embodiment, because it It is not necessary to move the pinion 7 in the axial direction of the output shaft 5, unlike a conventional electromagnetic thrust type starter configured to push its pinion into a meshing position with a motor-side crown. .

  The preferred embodiments explained above are examples of the invention of the present application which is described only by the appended claims below. It should be understood that modifications of the preferred embodiments may be made as would be apparent to those skilled in the art. i

Claims (9)

  1. Starter of the type with permanent meshing (1), characterized in that it comprises: an electric starter motor (3) generating a torque at its armature shaft (13) when it is electrically powered, a output shaft (5) coupled to said armature shaft (13), a pinion (7) disposed on said output shaft (5) and always meshing with a gear wheel on the motor side, and a clutch preventing reverse rotation (8) configured to allow said armature shaft (13) to rotate in the normal direction to thereby drive a motor in the normal direction, and to prevent said armature shaft (13) from being rotated in the direction inverse when said output shaft (5) is applied a reverse torque transmitted from said motor rotating in a reverse direction.   2. A permanent engagement type starter (1) according to claim 1, characterized in that said armature shaft (13) and said output shaft (5) are coupled to each other via a speed reduction device (6) configured to transmit a rotation of said armature shaft (13) to said output shaft (5) while reducing the speed of said rotation, said reverse rotation preventing clutch (8) being disposed on said armature shaft (13) and configured to prevent said armature shaft (13) from being rotated in the opposite direction when said reverse torque is transmitted to said clutch preventing reverse rotation (8) through said speed reduction device (6).   3. A permanent engagement type starter (1) according to claim 2, characterized in that said clutch preventing reverse rotation (8) comprises a fixed outer clutch portion (26), an inner clutch portion (27). disposed on said armature shaft (13), and clutch rollers (29) disposed between said fixed clutch outer portion (26) and said clutch inner portion (27), said clutch preventing reverse rotation ( 8) being configured so that said clutch rollers (29) rotate idle to allow said inner clutch portion (27) to rotate when said armature shaft (13) rotates in the normal direction to start said motor, and are locked in a gap between said fixed clutch outer portion (26) and said clutch inner portion (27) to prevent said clutch inner portion (27) from rotating such that said armature shaft (27) 13) is prevented from entering 1'né rotation in the opposite direction under the action of said reverse torque.   4. A permanent engagement type starter (1) according to claim 2, characterized in that said speed reduction device (6) is provided with a shock absorbing device (18) for absorbing a larger torque. a predetermined torque transmitted from said motor to said output shaft (5).   A permanent engagement type starter (1) according to claim 3, characterized in that said speed reduction device (6) is provided with a shock absorbing device (18) for absorbing a larger torque. a predetermined torque transmitted from said motor to said output shaft (5).   A permanent meshing type starter (1) according to claim 4, characterized in that said speed reduction device (6) comprises a sun gear (14) formed in a first end of said armature shaft (13), an annular gear (15) coaxial with said sun gear (14), and a plurality of planet gears (16) meshing with said sun gear (14) and said ring gear (15), orbital motion of said planet gears ( 16) around said sun gear (14) resulting from the rotation of said armature shaft (13) being transmitted to said output shaft (5), and wherein said shock absorbing device comprises a rotatable disc (22) coupled to said ring gear (15), and a fixed friction plate (20) which is in frictional contact with said rotary disk (22). z   A permanent meshing type starter (1) according to claim 5, characterized in that said speed reduction device (6) comprises a sun gear (14) formed in a first end of said armature shaft (13), an annular gear (15) coaxial with said sun gear (14), and a plurality of planet gears (16) meshing with said sun gear (14) and said ring gear (15), orbital motion of said planet gears ( 16) around said sun gear (14) resulting from the rotation of said armature shaft (13) being transmitted to said output shaft (5), and wherein said shock absorbing device comprises a rotating disk (22) coupled to said ring gear (15), and a fixed friction plate (20) which is in frictional contact with said rotary disk (22).   8. Starter of the type with permanent meshing (1) according to claim 1, characterized in that it further comprises a freewheel clutch integral with said pinion (7) on said output shaft (5), said clutch freewheeling being configured to allow torque transmission from said output shaft (5) to said pinion (7) when the rotation speed of said output shaft (5) is greater than the rotational speed of said pinion (7), and to block the transmission torque of said pinion (7) to said output shaft (5) when said rotational speed of said pinion (7) is greater than said rotational speed of said output shaft (5).   9. A permanent engagement type starter (1) according to claim 1, characterized in that it further comprises a supply circuit controlling the supply of said starter motor (3) according to a command received from a external system for automatic engine shutdown / restart.