JP2014238078A - Starter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To further reduce collision noise of a pinion and a ring gear in a starter.SOLUTION: In a starter 1, each of gear teeth 15 of a pinion 5 is formed by axially laminating a high-elasticity layer 26 formed from a steel plate 27 and a low-elasticity layer 25 (low-elasticity part 15a) formed from a resin plate 28. Thus, in the case where axial end faces of the gear teeth 15 of the pinion 5 collide with axial end faces of gear teeth 15 of a ring gear R, impact can be absorbed by the low-elasticity parts 15a, and gear end face collision noise can be reduced. Further, since the pinion 5 is partially formed from a resin, the pinion 5 becomes lightweight and collision power can be prevented from becoming excessive.

Description

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

In recent years, in order to deal with the problem of global warming, so-called idle stops have been introduced in automobiles that use internal combustion engines to improve fuel efficiency by stopping the engine when it is stopped for the purpose of reducing carbon dioxide (CO ₂ ). The movement to do is accelerating. However, in idling stop, the number of cases where a large number of vehicles start the engine at the same time on a general road in a traffic jam increases, so there is a concern about the noise problem around the road due to the sound generated when the engine is started. Therefore, in order to spread idle stop, it is considered that the reduction of sound generated at the time of engine start becomes a problem. The sound generated when the engine is started includes the operation sound of the starter.

  The main starter operating sounds are gear sounds generated when the pinion collides with the ring gear of the engine and meshes with it, and electromagnetic switch operating sounds. Reduction of these gear sounds and electromagnetic switch operating sounds This is important as a countermeasure for the source of sound generated at start-up.

  The gear noise generated between the pinion and the ring gear includes the gear end surface collision sound generated when the axial end surface of the pinion gear teeth collides with the axial end surface of the gear teeth of the ring gear, and the pinion meshes with the ring gear. There is a gear meshing sound that occurs when the motor rotates.

  In Patent Document 1, as a technique for reducing gear noise, a technique is disclosed in which a pinion is formed by laminating a plurality of steel plates, and the gear tooth portions of each steel plate are bent in the axial direction. Yes.

However, in this technique, since the pinion is composed only of a steel plate, the mass is large, and the collision force when the pinion collides with the ring gear tends to increase.
For this reason, although the gear noise can be reduced to some extent, there is a limit in this structure in order to meet the demand for further reducing the gear noise.

JP 2010-144554 A

  Therefore, the present invention has been made to solve the above-described problems, and an object thereof is to further reduce the collision noise between the pinion and the ring gear in the starter.

  The starter of the present invention includes a motor that generates a rotational force, a pinion that is rotatably and axially movable on an output shaft of the motor, and that can mesh with a ring gear of the engine, and the pinion is directed toward the ring gear. This is a starter that engages the pinion with the ring gear by moving in the axial direction.

  The pinion has a plurality of gear teeth arranged in the circumferential direction, and each of the plurality of gear teeth has a low elastic portion formed of a material having a smaller elastic coefficient than that of other portions.

  According to this, the impact at the time of the collision with the ring gear can be absorbed by the low elastic portion, and the collision sound can be reduced.

1 is an overall configuration diagram of a starter (Example 1). FIG. (A) is a top view of a pinion, (b) is a side view of a pinion (Example 1). FIG. 3 is a sectional view taken along the line III-III in FIG. 2 (Example 1). (Example 1) which is a fragmentary perspective view of a pinion. (Example 1) which is a top view of the state which the pinion and the ring gear meshed | engaged. (A), (b) is VI-VI sectional drawing of FIG. 5 before and behind a deformation | transformation (Example 1). (Example 2) which is a top view of a pinion. (Example 2) which is VIII-VIII sectional drawing of FIG. (Example 3) which is a top view of a pinion. (Example 3) which is XX sectional drawing of FIG.

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

[Example 1]
[Configuration of Example 1]
The configuration of the first embodiment will be described with reference to FIGS.
The starter 1 includes a motor 2 that generates a rotational force, an output shaft 3 to which the rotation of the motor 2 is transmitted, a one-way clutch 4 and a pinion 5 arranged on the output shaft 3, and a shift lever (not shown). 1) and the function of pushing the one-way clutch 4 and the pinion 5 to the ring gear R side (left direction in FIG. 1) and the function of switching the power supply to the motor 2 by opening and closing the main contact provided in the motor circuit. It is composed of a switch 8 and the like.

  The motor 2 is a well-known DC motor that is supplied with power from a battery (not shown) and generates a rotational force on an armature shaft (not shown) when the main contact is closed by the electromagnetic switch 8.

  One end side (left side in the figure) that is on the side opposite to the axial direction is rotatably supported by the housing 12, and the other end side end is connected to the armature shaft. Note that a reduction device (for example, a planetary gear reducer) may be provided between the armature shaft and the output shaft 3, and the rotation of the armature shaft may be reduced by the reduction device and transmitted to the output shaft 3.

  The one-way clutch 4 includes an outer 4a that is fitted to a helical spline portion 3a provided on the outer periphery of the output shaft 3, an inner 4b that is relatively rotatably disposed on the inner periphery of the outer 4a, and an outer 4a and an inner 4b. The roller 4c etc. which intermittently transmit transmission of a rotational force between them. A rotational force is transmitted in only one direction from the outer 4a to the inner 4b via the roller 4c.

  The pinion 5 is a rotating body having a plurality of gear teeth 15 arranged in the circumferential direction, and is directly splined to the outer periphery of an inner tube 4d that extends the inner 4b toward the opposite side of the motor in the axial direction. In other words, the pinion 5 is supported so as to rotate integrally with the inner tube 4d and to be movable by a predetermined distance in the axial direction with respect to the inner tube 4d. The inner tube 4d is fitted on the outer periphery of the output shaft 3 so as to be relatively rotatable.

  A pinion stopper 18 for restricting the movement of the pinion 5 on the inner tube 4d to the side opposite to the axial direction on the inner tube 4d is provided at the tip of the inner tube 4d. The tip end surface of the pinion 5 is in contact with the pinion stopper 18.

  The electromagnetic switch 8 is configured by using a well-known solenoid that forms an electromagnet by energizing a built-in electromagnetic coil (not shown) to attract a plunger (not shown). Is closed. When energization of the electromagnetic coil stops and the electromagnetic force disappears, the plunger is pushed back by the reaction force of a return spring (not shown) to open the main contact.

  The main contact is integrally movable with a set of fixed contacts connected to the motor circuit via two terminal bolts 20 and 21 fixed to the electromagnetic switch 8 and a plunger of the electromagnetic switch 8 and fixed together. It is formed with the movable contact which electrically connects between contacts.

  The shift lever is connected to a shift rod (not shown) having a lever end on one end side of the lever fulcrum serving as the pivot center, and the lever end on the other end side of the lever fulcrum is one. Engaging the directional clutch 4 transmits the movement of the plunger to the unidirectional clutch 4.

[Operation of starter 1]
By actuating the electromagnetic switch 8, the pinion 5 is pushed out in the counter-motor direction integrally with the one-way clutch 4 through the shift lever.
At this time, the gear teeth Ra of the ring gear R and the gear teeth 15 of the pinion 5 may not engage with each other, and the axial end surface of the gear tooth Ra of the ring gear R and the axial end surface of the gear tooth 15 of the pinion 5 may contact each other.

  Then, after the contact, when the relative position in the rotational direction of the pinion 5 and the ring gear R becomes a meshable position due to rotation by the motor 2 or the action of the helical spline portion 3a, the pinion 5 is further pushed out and the ring gear R The rotation of the motor 2 is transmitted from the pinion 5 to the ring gear R, and the engine is cranked.

[Features of this embodiment]
According to the starter 1 of the present embodiment, each of the plurality of gear teeth 15 has a low elastic portion 15a formed of a material having a smaller elastic coefficient than other portions.
In the present embodiment, the gear teeth 15 include an axial direction in which a high elastic layer 26 made of a material having a high longitudinal elastic modulus such as a steel material and a low elastic layer 25 having a lower longitudinal elastic modulus than a high elastic layer made of resin, rubber, or the like. It is laminated and configured. And the low elastic layer 25 makes the low elastic part 15a.

Specifically, the pinion 5 has a structure in which steel plates 27 and resin plate materials (hereinafter referred to as resin plates 28) having a lower longitudinal elastic modulus than the material of the steel plates 27 are alternately laminated in the axial direction. ing. The number of layers and the thickness of each layer are appropriately set according to the required strength and the like.
The steel plate 27 and the resin plate 28 are fixed at least at a portion on the inner diameter side of the tooth bottom by bonding, fastening, or the like.

  Each of the steel plate 27 and the resin plate 28 has a gear tooth shape, and the gear teeth 15 are formed by being laminated. That is, the gear teeth 15 have a structure in which the high elastic layer 26 made of the steel plate 27 and the low elastic layer 25 made of the resin plate 28 are alternately laminated.

Further, as shown in FIGS. 2A, 3, and 4, in the gear teeth 15, the tooth thickness of the low elastic layer 25 is larger than the tooth thickness of the high elastic layer 26 over the entire teeth. .
In this embodiment, the portion forming the gear teeth 15 of the resin plate 28 bulges in the circumferential direction than the portion forming the gear teeth 15 of the steel plate 27.

  Therefore, as shown in FIGS. 5 and 6 (a), when the pinion 5 and the ring gear R are engaged with each other and rotated, the position in the radial direction of the gear tooth 15 with which the ring gear R abuts is defined as a position A. When the tooth thickness in A is the pitch point tooth thickness, the pitch point tooth thickness t1 in the low elastic layer 25 is larger than the pitch point tooth thickness t2 in the high elastic layer 26.

[Effects of Example 1]
In the starter of this embodiment, the gear teeth 15 are configured by laminating a high elastic layer 26 made of a steel plate 27 and a low elastic layer 25 (low elastic portion 15a) made of a resin plate 28 in the axial direction.

According to this, the impact when the axial end surface of the gear teeth 15 of the pinion 5 collides with the axial end surface of the gear teeth 15 of the ring gear R can be absorbed by the low elastic portion 15a, and the gear end surface collision noise can be reduced. it can.
In addition, since a part of the pinion 5 is formed of resin, it is possible to avoid the pinion 5 being light in weight and the collision force becoming excessive.

Further, the gear teeth 15 have a tooth thickness at the low elastic layer 25 larger than a tooth thickness at the high elastic layer 26.
According to this, as shown in FIG. 6, when the pinion 5 and the ring gear R are meshed and rotated, the low elastic portion 15a comes into contact with the ring gear R first, and the low elastic portion 15a is elastically deformed (FIG. 6B). ))) To absorb the impact. Thereby, a gear meshing sound can be reduced.

  That is, the impact at the time of collision with the ring gear R can be absorbed by the low elastic portion 15a, and collision noise can be reduced.

[Example 2]
A second embodiment will be described with reference to FIGS. 7 and 8 with a focus on differences from the first embodiment.
In addition, the same code | symbol as Example 1 shows the same functional thing, Comprising: The previous description is referred.
In this embodiment, the resin layer 31 (low elastic layer 25) and the metal layer 32 (high elastic layer 26) are formed on the gear teeth 15 by insert molding.
For example, the resin layers 31 are formed on both ends of the gear teeth 15 in the axial direction, and the resin layers 31 are insert-molded so that the resin layers 31 are connected by the connecting portions 33 on the inner diameter side of the gear teeth 15.
Also according to the present embodiment, the same effects as those of the first embodiment can be obtained.

Example 3
A third embodiment will be described with reference to FIGS. 9 and 10 with a focus on differences from the first embodiment.
In addition, the same code | symbol as Example 1 shows the same functional thing, Comprising: The previous description is referred.
In the present embodiment, resin portions 35 that bulge in the circumferential direction are attached to both side surfaces of each gear tooth 15 in the circumferential direction with respect to the gear teeth 15 formed of metal by insert molding.
For example, in this embodiment, three resin portions 35 are provided on each side surface in the axial direction.

According to this, when the resin portion 35 forms the low elastic portion 15a and the pinion 5 and the ring gear R are engaged with each other and rotated as in the first embodiment, the low elastic portion 15a comes into contact with the ring gear R first and the low Due to the elastic deformation of the elastic portion 15a, it is possible to absorb the impact and reduce the collision sound.
In this embodiment, unlike the first and second embodiments, the low elastic layer 25 and the high elastic layer 26 are not alternately laminated in the axial direction. Example 2 is higher.

(Modification)
The starter 1 of the first embodiment is a type in which both the pinion 5 and the one-way clutch 4 are pushed out by the shift lever 7, but may be a type in which only the pinion 5 is pushed out.
Further, the electromagnetic switch 8 may be a tandem type that includes two solenoids, a solenoid that pushes the pinion 5 in the axial direction and a solenoid that turns on and off the energization current of the motor.

1 Starter, 2 Motor, 3 Output shaft, 5 Pinion, 15 Gear teeth, 15a Low elastic part

Claims (3)

A motor (2) for generating a rotational force;
A pinion (5) disposed on the output shaft (3) of the motor (2) so as to be rotatable and movable in the axial direction, and capable of meshing with an engine ring gear (R);
A starter of a type in which the pinion (5) is engaged with the ring gear (R) by moving the pinion (5) in the axial direction toward the ring gear (R),
The pinion (5) has a plurality of gear teeth (15) arranged in the circumferential direction,
Each of the plurality of gear teeth (15) has a low elastic part (15a) formed of a material having a smaller elastic coefficient than that of the other part in each of the plurality of gear teeth (15). The starter according to claim 1,
The gear teeth (15) include a high elastic layer (26) made of a material having a high elastic modulus, and a low elastic layer (25) made of a material having a lower elastic modulus than the material forming the high elastic layer (26). Are stacked in the axial direction,
The starter characterized in that the low elastic layer (25) forms the low elastic portion (15a). The starter according to claim 2,
When the tooth thickness of the gear teeth (15) at the position where the ring gear (R) abuts when the pinion (5) and the ring gear (R) rotate while meshing with each other,
The pitch point tooth thickness t1 in the low elastic layer (25) is larger than the pitch point tooth thickness t2 in the high elastic layer (26).

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