JP4273198B2 - Starter for internal combustion engine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starter for an internal combustion engine mounted on an automobile or the like.
[0002]
[Prior art]
As a starting device for starting an internal combustion engine of an automobile, a starter motor using a vehicle battery as a power source is generally used. This type of starting device includes a pinion gear that meshes with a ring gear provided on the outer periphery of an internal combustion engine flywheel or the like. The pinion gear meshes with the ring gear at the start, and after the start is completed, the pinion gear is separated from the ring gear and returns to the original position. Therefore, a spur gear is used for the pinion gear and the ring gear of the conventional starting device in order to facilitate the engagement and disengagement of each other.
[0003]
Since the conventional starter uses spur gears for the pinion gear and the ring gear, relatively large vibrations and noises are generated due to backlash between the gears during rotation. However, in conventional vehicles, the pinion gear and the ring gear mesh only when the driver turns on the starter switch at the start, and when the starter switch is turned off, the gear is disengaged. Even if spur gears were used, no major problem occurred.
[0004]
[Problems to be solved by the invention]
However, in a vehicle such as an idle stop vehicle or a hybrid car in which the internal combustion engine is repeatedly started or stopped automatically by a signal from the in-vehicle computer, the internal combustion engine is started regardless of the driver's intention. Further, since the starting frequency increases, the noise generated from the starting device becomes annoying. Even in the case of an automobile that is started by a normal starter switch, it is desirable that the noise at the start is low from the viewpoint of quietness. In order to reduce noise, it is necessary to increase the meshing ratio and meshing accuracy of the teeth. However, since the gear ratio or the tooth width is restricted due to the starter capacity and layout, etc., the meshing ratio is reduced with the conventional spur gear. There is a limit to improvement, and simply improving the engagement rate and engagement accuracy makes it difficult for the pinion gear to mesh with the ring gear at the start and makes it difficult for the pinion gear to separate from the ring gear after the start. .
[0005]
Accordingly, an object of the present invention is to provide a starter for an internal combustion engine that can reduce noise generated from the starter and realize a more comfortable vehicle or the like.
[0008]
[Means for Solving the Problems]
The starting device according to claim 1 for achieving the object is provided with a detachable pinion gear, and the pinion gear rotates in the tooth width direction toward the ring gear side in the rotational direction of the pinion gear. The ring gear is formed of a helical gear that can mesh with the pinion gear, and the pinion gear formed of the helical gear is a main gear. A scissor gear mechanism having a gear, a sub-gear, and a torque spring that biases the sub-gear so that the position of the sub-gear is shifted in the circumferential direction, and each tooth surface of the main gear and the sub-gear has a tooth surface of the ring gear. By pinching the tooth surface, the backlash between the pinion gear and the ring gear is eliminated, and the pinion gear is When each of the helical gears constituting the ring gear protrudes toward the ring gear, the thrust force generated on the contact surfaces of the helical gears is generated by the pinion gear that rotates at the time of starting. When the pinion gear disengages from the ring gear that rotates in the direction that further meshes the gear and the ring gear and rotates after starting, the thrust force generated on the contact surfaces of the helical gears causes the pinion gear to Inclined to act in the direction to be separated from the ring gear, and at the end of each ring gear tooth on the side where the pinion gear enters, the distance between the teeth toward the pinion gear is different from that of the main gear. A tapered surface is formed that extends to allow the sub gear to enter.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a starting device of a first reference example will be described with reference to FIGS.
A starter 11A of an automobile internal combustion engine 10 shown in FIG. 1 includes a starter motor 12, a pinion gear 14 attached to an output shaft 13 of the starter motor 12, and a ring that always meshes with the pinion gear 14. A gear 15 is provided. The pinion gear 14 and the ring gear 15 are each formed of a helical gear (helical gear) described later.
[0010]
A flywheel 21 is fastened to the crankshaft 20 of the internal combustion engine 10 by bolts 22 so that the crankshaft 20 and the flywheel 21 are integrated with each other and rotate in the same direction. The ring gear 15 is supported by a bearing 23 provided on the flywheel 21 so as to be rotatable about the crankshaft 20.
[0011]
A one-way clutch 30 is provided between the ring gear 15 and the crankshaft 20 to allow only transmission of driving force from the starter motor 12 side to the internal combustion engine 10 side (crankshaft 20). In the case of the reference example shown in FIG. 1, the one-way clutch 30 is built in between the ring gear 15 and the flywheel 21. A manual transmission clutch mechanism 31 is attached to the flywheel 21. In the case of an automatic transmission, a torque converter that rotates integrally with the crankshaft 20 is attached instead of the clutch mechanism 31, and the ring gear 15 is provided in the torque converter.
[0012]
The pinion gear 14 is constituted by a helical gear provided with a scissor gear mechanism 40 as shown in FIGS. The scissor gear mechanism 40 includes a main gear 41, a sub gear 42, a torque spring 43, and the like, and is attached to the output shaft 13 by a nut 44. The sub gear 42 is biased so as to be displaced in the circumferential direction with respect to the main gear 41 by the repulsive load of the torque spring 43, and the teeth of the main gear 41 and the sub gear 42 sandwich the teeth of the ring gear 15. The backlash between the gears 14 and 15 is eliminated.
[0013]
Next, the operation of the starter 11A having the above configuration will be described.
In the starter 11A, the pinion gear 14 and the ring gear 15 are always meshed. When a current is passed through the starting motor 12 to start the internal combustion engine 10 and the output shaft 13 is rotated, the driving force is transmitted to the one-way clutch 30 via the pinion gear 14 and the ring gear 15.
[0014]
When the driving force is transmitted from the starting motor 12 in the direction of the crankshaft 20 in this way, the one-way clutch 30 is connected, so that the rotation of the ring gear 15 is transmitted to the flywheel 21 via the one-way clutch 30 and integrated with the flywheel 21. When the crankshaft 20 rotates, the internal combustion engine 10 is cranked. When the starter motor 12 is stopped after the start is completed, the driving force is input to the one-way clutch 30 from the crankshaft 20 side, contrary to the start. Since the one-way clutch 30 idles in response to the input in this direction, the driving force of the crankshaft 20 is not transmitted to the ring gear 15, and therefore, it is avoided that the driving force is transmitted to the pinion gear 14 and the starting motor 12.
[0015]
Since the pinion gear 14 and the ring gear 15 of this reference example are made of a helical gear with a scissor gear mechanism 40, the meshing ratio between the gears 14 and 15 is extremely high and substantially no backlash occurs. Therefore, it can rotate with low vibration and low noise. Note that a scissor gear mechanism may be employed on the ring gear 15 side if cost permits .
[0016]
Further, as in the second reference example shown in FIG. 5, the one-way clutch 45 is interposed between the output shaft 13 and the pinion gear 14 of the starter motor, thereby driving from the starter motor side to the internal combustion engine side. Only the transmission of force may be allowed, and the output shaft 13 may not be rotated by the pinion gear 14 idling with respect to the input from the reverse direction.
[0017]
Next, the starting device 11B according to the first embodiment of the present invention will be described with reference to FIGS. In addition, the same code | symbol is attached | subjected to the part which is common in the starter 11A of the said 1st reference example , and description is abbreviate | omitted.
[0018]
The pinion gear 14 of the starting device 11B of this embodiment is a detachable type, and the direction of meshing with the ring gear 15 and the ring gear 15 by an electromagnetic coil and a plunger (not shown) incorporated in the starting electric motor 50 and the like. It can be moved in the direction of separation (indicated by arrow A). The pinion gear 14 is formed of a helical gear provided with a scissor gear mechanism 40 as in the first reference example . The ring gear 15 is formed of a helical gear that can mesh with the pinion gear 14.
[0019]
The pinion gear 14 of this embodiment is configured to mesh with the ring gear 15 by projecting toward the ring gear 15 when a current is supplied to the starter motor 50.
[0020]
The pinion gear 14 of this embodiment has a rotational direction of the pinion gear 14 toward the ring gear 15 side in the tooth width direction, as schematically shown in FIG. It is constituted by a helical gear having teeth inclined to the right. Further, a tapered surface 51 is formed on the main gear 41 of the pinion gear 14 in order to facilitate insertion into the ring gear 15.
[0021]
Further, tapered surfaces 52 and 53 are formed on end surfaces of the ring gear 15 and the sub gear 42 that face each other so that the pinion gear 14 can easily mesh with the ring gear 15 and to prevent tooth chipping during meshing. . In consideration of the mutual meshing properties, these tapered surfaces 52, 53 are arranged so that the angle θ (shown in FIGS. 7 and 10) formed with the tip surface with respect to the driving direction is approximately 90 °. 53 is preferably formed. When the angle θ is an acute angle, tooth missing is likely to occur during meshing.
[0022]
Next, the operation of the starter 11B will be described.
When the pinion gear 14 protrudes toward the ring gear 15 at the time of starting, the driving force F1 is input to the ring gear 15 from the pinion gear 14 side as shown in FIG. 7, and thus the contact surface 55 between the helical gears is inclined. The generated thrust force F2 acts in a direction in which these gears 14 and 15 are further meshed. For this reason, the pinion gear 14 is easily meshed with the ring gear 15.
[0023]
Then, when the output shaft 13 of the starter motor 50 rotates, the driving force of the output shaft 13 is transmitted to the crankshaft 20 of the internal combustion engine 10 via the ring gear 15, and cranking is performed to start the internal combustion engine 10. .
[0024]
Further, when the pinion gear 14 is disengaged from the ring gear 15 after the start is completed, the driving force is input to the pinion gear 14 from the ring gear 15 side as shown in FIG. A thrust force F <b> 3 generated on the contact surface 55 acts in a direction in which the pinion gear 14 is separated from the ring gear 15. For this reason, the pinion gear 14 is easily separated from the ring gear 15 after the start is completed.
[0025]
In addition, the comparative example shown in FIG. 9 shows a case where the inclination directions of the helical gear teeth of the pinion gear 14 ′ and the ring gear 15 ′ are opposite to those in the above-described embodiment (FIGS. 7 and 8). In such a comparative example (FIG. 9), when the driving force F1 is input from the pinion gear 14 'side at the time of starting, the thrust force F4 generated on the contact surface 55' inclined between the helical gears is changed to the pinion gear 14 '. Acts in the direction of pushing out from the ring gear 15 '. For this reason, it becomes difficult for the pinion gear 14 'to mesh with the ring gear 15'. In addition, after starting, when the driving force is input from the ring gear 15 'side, the thrust force acts in a direction to hold the meshing of the gears 14' and 15 ', so that the pinion gear 14' is detached from the ring gear 15 '. It becomes difficult to do.
[0026]
As in the scissor gear mechanism 40 of the pinion gear 14 of the second embodiment shown in FIG. 10, the main gear 41 is positioned on the side facing the ring gear 15. The sub gear 42 may be configured to mesh with the ring gear 15 after the fitting. In this case, the sub gear 42 is formed with a tapered surface 60 in order to facilitate insertion into the ring gear 15. Since the other configuration and operation are the same as those of the first embodiment, the same reference numerals are given to the portions common to the first embodiment, and the description thereof will be omitted.
[0027]
Na us, carrying out the invention of this, including the pinion gear, starting motor and the ring gear, such as one-way clutch, it is needless to say that the elements constituting the present invention can be modified and implemented as appropriate respectively.
[0028]
【The invention's effect】
According to the starting apparatus as claimed in claim 1, in the case of using the fitting de type pinion gears, the pinion gear consisting of helical gears is easily able to mate the ring gear, after starting the pinion gear It can be easily detached from the ring gear. In the present invention , since the pinion gear and the ring gear are helical gears each having a scissor gear mechanism, the meshing ratio between the gears is extremely high, and substantially no backlash is generated. Can rotate with noise.
[Brief description of the drawings]
FIG. 1 is a side view showing a starting device of a first reference example with a partial cross section.
FIG. 2 is a cross-sectional view of a pinion gear provided with a scissor gear mechanism used in the starting device shown in FIG.
3 is a perspective view of the pinion gear shown in FIG. 2. FIG.
4 is an exploded perspective view of the pinion gear shown in FIG.
FIG. 5 is a side view showing a partial cross section of a pinion gear including a one-way clutch according to a second reference example .
FIG. 6 is a side view of the starting device showing the first embodiment of the present invention.
7 is a schematic view showing a tooth movement path when the pinion gear shown in FIG. 6 meshes with a ring gear. FIG.
FIG. 8 is a schematic diagram showing a tooth movement path when the pinion gear shown in FIG. 6 is separated from the ring gear;
FIG. 9 is a schematic view showing a thrust force generated when a pinion gear of a comparative example meshes with a ring gear.
FIG. 10 is a schematic view showing a tooth movement path when the pinion gear according to the second embodiment of the present invention meshes with the ring gear.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 ... Internal combustion engine 11A, 11B ... Starter 12 ... Starter motor 13 ... Output shaft 14 ... Pinion gear 15 ... Ring gear 20 ... Crankshaft 30, 45 ... One-way clutch 50 ... Starter motor

Claims (2)

A pinion gear provided on the output shaft of the starter motor is detachably engaged with a ring gear that rotates integrally with the crankshaft of the internal combustion engine, and power is transmitted from the starter motor to the crankshaft to transmit the power to the crankshaft. In the starting device for starting
The pinion gear is formed by a helical gear constituted by teeth inclined in the rotation direction of the pinion gear as it goes toward the ring gear in the tooth width direction, and the ring gear is meshable with the pinion gear. Formed by helical gears,
The pinion gear constituted by the helical gear is composed of a scissor gear mechanism having a main gear, a sub gear, and a torque spring that urges the sub gear to be displaced in the circumferential direction with respect to the main gear. by each tooth surface of the main gear and the sub-gear is sandwich the tooth surface of the ring gear state, and are not to eliminate the backlash between the pinion gear and the ring gear, and,
When each of the helical gears constituting the pinion gear and the ring gear protrudes toward the ring gear, the thrust force generated on the contact surfaces of the helical gears when the pinion gear rotating at the time of start-up protrudes toward the ring gear. Acts in the direction in which these pinion gear and ring gear further mesh, and when the pinion gear disengages from the ring gear that rotates after starting, the thrust force generated on the contact surface between the helical gears is the pinion gear. Inclines to act in the direction to disengage the gear from the ring gear, and
A tapered surface is formed at the end of each ring gear tooth on the side where the pinion gear enters, so that the distance between the teeth toward the pinion gear widens to allow the main gear and the sub gear to enter. starting system for an internal combustion engine, characterized in that it is. The starter for an internal combustion engine according to claim 1 , wherein the main gear or the sub gear of the pinion gear is formed with a tapered surface for smooth insertion into the ring gear.

Images