JP3713800B2 - Starter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a starter for starting an engine.
[0002]
[Prior art]
Conventionally, a starter provided with a planetary gear reduction device and a one-way clutch is known (see Japanese Utility Model Laid-Open No. 50-45522). Since this starter requires a clutch cover, the number of parts increases, and the assembly man-hour accompanying it increases. Further, since the outer is centered only on one side of the roller in the axial direction, the balance of the outer is easily lost during high-speed rotation. Furthermore, there has been a problem that the entire length in the axial direction becomes longer due to the necessity of setting the press-fitting length of the pin press-fitted into the outer.
[0003]
Therefore, the present applicant has applied for a starter (Japanese Patent Application No. 7-238127) for solving the above problems. In this starter, a pin supporting the planetary gear is press-fitted into the outer through the side of the roller. Thereby, since an outer and a planet carrier can be made into the same component, the length of an axial direction can be shortened rather than the conventional starter (The starter of the structure where the outer and the planet carrier shifted | deviated to the axial direction). Further, a restriction plate for restricting the axial movement of the roller is disposed on the end face of the outer, and this restriction plate is press-fitted and fixed to the pin. For this reason, since the clutch cover for fixing the restriction plate is not required, the number of parts and the number of assembling steps can be reduced. Further, the outer plate is integrally provided with a regulating portion for regulating the movement of the roller together with the regulating plate. The inner circumferential surface of the regulating portion and the inner circumferential surface of the regulating plate are the outer circumferential surface of the inner or the outer circumferential surface of the output shaft. It is possible to reliably center the outer by abutting against.
[0004]
[Problems to be solved by the invention]
However, the following problems occur in the starter of the prior application.
(1) When a pin is press-fitted into the outer, a tensile stress is generated on the cam surface of the outer and the stress remains in the outer, so that the fatigue resistance of the outer is lowered. For this reason, the design is subject to a restriction that the thickness of the outer pin hole and the cam surface must be increased.
(2) Since it is necessary to form a press-fitting hole for press-fitting a pin into the outer by deep hole machining, the number of machining steps is increased and the cost is increased.
(3) Since a plurality of pins are press-fitted into the regulation plate, it is necessary to process each hole opened in the regulation plate with high accuracy.
(4) If the regulating plate is not completely in close contact with the outer end face, the grease in the cam chamber may come off, which may cause the roller to wear.
The present invention has been made based on the above circumstances, and an object thereof is to provide a starter that solves the above-described problems.
[0005]
[Means for Solving the Problems]
Claims inventions Section 1, the planetary gear reduction device for reducing the rotational speed of the motor, the outer rotation of the motor is transmitted through the planetary gear reduction device, the inner peripheral surface formed cam chamber of the outer And a one-way clutch having an inner to which rotation of the outer is transmitted through the roller, and a support shaft for supporting the planetary gear of the planetary gear reduction device is press-fitted into the outer. The outer is composed of an outer cylindrical member and an inner cylindrical member that divide the press-fitting hole into which the support shaft is press-fitted in the radial direction, and the outer cylindrical member and the inner cylindrical member are fixed to each other by press-fitting. Therefore, it is possible to form a press-fitting hole by forming a groove recessed in a semicircular cross section in each cylindrical member and combining the grooves. In this case, conventional deep hole machining is not required to form the press-fitting hole, and grooves can be easily formed by pressing or cold forging when machining each cylindrical member. You can go down.
[0006]
In the invention of claim 2, at least a part of the support shaft is press-fitted into the press-fitting hole so as to overlap in the radial direction of the roller. In this case, since the cam surface (inner wall surface of the cam chamber) is formed on the inner periphery of the inner cylindrical member that overlaps the radial direction of the roller, the inner cylindrical member has a tensile force generated when the support shaft is press-fitted into the press-fitting hole. Stress and tensile stress generated by being pressed so as to be expanded from the roller during torque transmission are applied. With respect to this tensile stress, a compressive stress is applied to the inner cylindrical member by press-fitting with the outer cylindrical member, and the compressive stress works to improve the fatigue resistance of the inner cylindrical member. As a result, the thickness of the outer (inner cylindrical member) can be made thinner than before, so that a reduction in size and weight can be achieved.
[0007]
According to the third aspect, the movement of the roller in the axial direction can be restricted by the one wall portion of the outer cylindrical member and the other wall portion of the inner cylindrical member. For this reason, in addition to the outer cylindrical member and the inner cylindrical member, there is no need for a regulating plate for regulating the movement of the roller. ) Is not necessary, and the cost can be reduced.
In addition, since the outer cylindrical member and the inner cylindrical member overlap in the radial direction at the portion where the press-fitting hole is formed, the outer cylindrical member and the inner cylindrical member are formed over the entire radial direction from the inner peripheral surface to the outer peripheral surface of the outer. There is no place to contact in the axial direction. That is, there is no gap extending in the radial direction directly from the cam chamber to the outer peripheral surface of the outer, and a reliable oil retaining structure for the grease in the cam chamber can be provided.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the starter of the present invention will be described.
(First embodiment)
As shown in FIG. 3, the starter 1 is fitted with a starter motor 2 that generates a rotational force when energized, an output shaft 3 that rotates when the rotational force of the starter motor 2 is transmitted, and an outer periphery of the output shaft 3. A pinion gear 4 that rotates, a planetary gear reduction device that reduces the rotational speed of the starting motor 2 (described later), and a one-way clutch 5 that transmits the rotation reduced by the reduction device to the output shaft 3 (see FIGS. 1 and 2), The magnet switch 6 is configured to control energization to the starter motor 2 and generate a force for moving the pinion gear 4 on the output shaft 3.
[0009]
The starter motor 2 has an armature 9 in which both ends of a shaft 7 are rotatably supported via a bearing 8, a fixed magnetic pole 10 disposed on the outer periphery of the armature 9, and a cylindrical shape that holds the fixed magnetic pole 10 on the inner periphery. And a brush (not shown) that is in sliding contact with a commutator (not shown) provided at the other end (right side of FIG. 3) of the shaft 7. When the starter switch is turned on and a motor contact (not shown) built in the magnet switch 6 is closed, power is supplied through a brush from a battery (not shown) mounted on the vehicle.
[0010]
One end of the output shaft 3 is rotatably supported by the end of the housing 13 via the bearing 12, and the other end is rotatably supported by the center case 15 via the bearing 14. The other end of the output shaft 3 is formed with a hollow cylindrical recess 3a along the axial direction. The bearing 8 is disposed in the recess 3a to rotate one end of the shaft 7. Supports freely. A helical spline 3b is formed on the outer periphery of the output shaft 3, and a spline tube 16 provided integrally with the pinion gear 4 is fitted to the helical spline 3b.
The center case 15 covers the outer periphery of the speed reducer and the one-way clutch 5 and is sandwiched between the housing 13 and the yoke 11.
[0011]
The pinion gear 4 meshes with the ring gear 17 of the engine to transmit the rotational force of the starter motor 2 to the ring gear 17, and is provided integrally with the spline tube 16 so as to be able to advance and retreat on the output shaft 3 along the helical spline 3b. . However, the forward movement of the pinion gear 4 (the movement in the left direction in FIG. 3) is restricted by contacting a stop collar 18 attached to the outer periphery of the output shaft 3. The stop collar 18 is restricted from moving in the axial direction via a snap ring 19 fitted in a circumferential groove 3 c formed on the outer periphery of the output shaft 3.
[0012]
The speed reducer includes a sun gear 20 formed on the outer periphery of the shaft 7, a plurality of planetary gears 21 that mesh with the sun gear 20, and an internal gear 22 that meshes with each planetary gear 21.
The sun gear 20 rotates integrally with the shaft 7 to transmit the rotation of the shaft 7 to each planetary gear 21. The planetary gear 21 is rotatably supported on the outer periphery of a pin 24 (support shaft of the present invention) press-fitted into the outer 23 of the one-way clutch 5 via a bearing 25, and meshes with the sun gear 20 and the internal gear 22 to rotate. While rotating the outer periphery of the sun gear 20. The internal gear 22 is formed in the center case 15.
[0013]
As shown in FIG. 2, the one-way clutch 5 includes an outer 23, an inner 26, a roller 27, a spring 28, and the like.
As shown in FIGS. 1 and 2, the outer 23 includes an outer cylindrical member 23A and an inner cylindrical member 23B that are divided into two in the radial direction, and the outer cylindrical member 23A and the inner cylindrical member 23B are fixed to each other by press-fitting. Has been. Grooves 29a and 29b, each recessed in a semicircular cross section, are formed in the circumferential direction in the press-fitting surfaces of the outer cylindrical member 23A and the inner cylindrical member 23B, and both the cylindrical members 23A and 23B are fixed by press-fitting. The press-fitting hole 29 for press-fitting the pin 24 is formed by the grooves 29a and 29b formed in the cylindrical members 23A and 23B. The grooves 29a and 29b formed in the outer cylindrical member 23A and the inner cylindrical member 23B can be easily formed by a process such as pressing or cold forging.
[0014]
As shown in FIG. 2, a wedge-shaped cam chamber 30 that accommodates the roller 27 and a spring chamber 31 that accommodates the spring 28 are formed adjacent to each other on the inner peripheral side of the inner cylindrical member 23B. However, a plurality of cam chambers 30 and spring chambers 31 are formed at equal intervals in the circumferential direction of the inner cylindrical member 23B. The outer cylindrical member 23A has one wall portion 23a that closes one side of the cam chamber 30 and the spring chamber 31 along the axial direction of the pin 24 (left and right direction in FIG. 1). And the other wall portion 23b for closing the other side of the cam chamber 30 and the spring chamber 31 along the axial direction of the pin 24. Therefore, the cam chamber 30 and the spring chamber 31 include the inner peripheral surface of the inner cylindrical member 23B, the outer peripheral surface of the inner 26, one wall portion 23a of the outer cylindrical member 23A, and the other wall portion 23b of the inner cylindrical member 23B. To form a substantially sealed space. Further, as shown in FIG. 1, the inner peripheral surface of one wall 23 a is in sliding contact with the outer peripheral surface of the output shaft 3, and the inner peripheral surface of the other wall 23 b is in sliding contact with the outer peripheral surface of the inner 26. 23 and the output shaft 3 are centered.
[0015]
The inner 26 is provided integrally with the other end of the output shaft 3 on the inner periphery of the outer 23 and rotates integrally with the output shaft 3. The roller 27 is accommodated in the cam chamber 30, and movement in the axial direction is restricted by one wall portion 23a of the outer cylindrical member 23A and the other wall portion 23b of the inner cylindrical member 23B. The spring 28 is housed in the spring chamber 31 and biases the roller 27 toward the narrower side of the cam chamber 30 (counterclockwise direction in FIG. 2).
[0016]
The magnet switch 6 includes a coil (not shown) that is energized when the starter switch is turned on, a plunger (not shown) that is slidably disposed in the hollow interior of the coil, and the motor contact described above. By attracting the plunger by the magnetic force of the motor, the motor contact is closed and the lever 33 is driven through the joint 32 connected to the plunger.
The lever 33 has one end engaged with the joint 32 and the other end engaged with the outer periphery of the spline tube 16 so as to be swingable about a fulcrum 13 a provided on the housing 13.
[0017]
Next, the operation of this embodiment will be described.
When the starter switch is turned on, the motor contact in the magnet switch 6 is closed and the armature 9 is energized, whereby a rotational force is generated in the armature 9. Thereby, the sun gear 20 rotates together with the shaft 7 so that each planetary gear 21 revolves around the outer periphery of the sun gear 20 while rotating around the pin 24. The revolution force of the sun gear 20 is transmitted to the outer 23 through the pin 24, and further transmitted from the outer 23 to the inner 26 through the roller 27, whereby the output shaft 3 is rotationally driven.
[0018]
On the other hand, when the plunger suction force of the magnet switch 6 is transmitted to the spline tube 16 via the lever 33, the spline tube 16 and the pinion gear 4 move to the ring gear 17 side on the output shaft 3, and the pinion gear 4 meshes with the ring gear 17. Thus, the rotational force of the starting motor 2 is transmitted to the ring gear 17 to start the engine.
After the engine is started, when the pinion gear 4 rotates at a high speed and the rotation of the inner 26 becomes faster than the rotation of the outer 23, the roller 27 moves toward the wider side of the cam chamber 30 against the biasing force of the spring 28. Since the state of connection with the outer 23 is released and torque transmission from the inner 26 to the outer 23 is interrupted, overrun of the armature 9 can be prevented.
[0019]
(Effect of this embodiment)
In the present embodiment, the outer cylindrical member 23A and the inner cylindrical member 23B that divide the press-fitting hole 29 for press-fitting the pin 24 in the radial direction are fixed to each other by press-fitting. Thereby, compressive stress is given to inner cylinder member 23B which forms a cam surface by press-fitting with outer cylinder member 23A. The compressive stress is applied to the inner cylindrical member 23B against the tensile stress generated when the pin 24 is press-fitted into the press-fitting hole 29, and the tensile stress generated by being pressed so as to be expanded from the roller 27 during torque transmission. It works to improve fatigue strength. As a result, since the thickness from the cam surface to the press-fitting hole 29 (that is, the thickness of the inner cylindrical member 23B) can be reduced, the one-way clutch 5 can be reduced in size and weight.
[0020]
Further, when the outer cylindrical member 23A and the inner cylindrical member 23B are press-fitted, the press-fitting hole 29 can be formed by aligning the grooves 29a and 29b formed in both the cylindrical members 23A and 23B in the circumferential direction. In this case, the conventional deep hole processing is not required to form the press-fitting hole 29, and the grooves 29a and 29b can be easily formed by pressing or cold forging when processing the cylindrical members 23A and 23B. Costs can be reduced by reducing the number of processing steps.
[0021]
Further, the movement of the roller 27 in the axial direction can be restricted by the one wall portion 23a of the outer cylindrical member 23A and the other wall portion 23b of the inner cylindrical member 23B. For this reason, in addition to the outer cylindrical member 23A and the inner cylindrical member 23B, there is no need for a regulating plate for regulating the movement of the roller 27. Therefore, high-precision processing of the regulating plate (for press-fitting a plurality of pins 24) No hole processing is required, and the cost can be reduced.
Further, since the outer cylindrical member 23A and the inner cylindrical member 23B are overlapped in the radial direction at the portion where the press-fitting hole 29 is formed, the outer cylindrical member 23A and the outer cylindrical member 23A are formed over the entire radial direction from the inner peripheral surface to the outer peripheral surface of the outer 23. A location where the inner cylindrical member 23B abuts in the axial direction does not occur. That is, there is no gap extending in the radial direction from the cam chamber 30 directly to the outer peripheral surface of the outer 23 (outer cylindrical member 23A), and a reliable oil retaining structure for the grease in the cam chamber 30 can be provided.
[0022]
The inner cylindrical member 23B forming the cam surface has the outer cylindrical member 23A press-fitted to the outer periphery thereof, and the one wall portion 23a of the outer cylindrical member 23A on the opposite side of the other wall portion 23b with the roller 27 interposed therebetween. Therefore, even when the cam surface is pressed from the roller 27 during torque transmission, the mouth does not open. As a result, uniform pressure can be applied between the cam surface of the inner cylindrical member 23B and the roller 27, so that the inner 26 receiving pressure from the roller 27 can be prevented from being peeled off early, and the life of the one-way clutch 5 can be extended. Can be achieved.
[0023]
(Second embodiment)
FIG. 4 is a sectional view along the axial direction of the one-way clutch 5.
In the present embodiment, an example in which the pin 24 that pivotally supports the planetary gear 21 does not overlap the radial direction of the roller 27 of the one-way clutch 5 is shown. In this case, since it is not necessary to form a cam surface on the inner cylindrical member 23B, the radial position of the press-fitting hole 29 can be moved to the inner peripheral side as compared with the case of the first embodiment. As a result, it is possible to reduce the diameter of the one-way clutch 5 by reducing the thickness of the outer cylindrical member 23A. Further, according to the present embodiment, similarly to the first embodiment, it is not necessary to form the press-fitting hole 29 by deep hole processing, and the number of processing steps can be reduced, and a regulation plate for regulating the movement of the roller 27 is necessary. Therefore, it is not necessary to process the regulating plate with high accuracy, so that the cost can be reduced. Further, since there is no gap extending in the radial direction from the cam chamber 30 directly to the outer peripheral surface of the outer 23 (outer cylindrical member 23A), a reliable oil retaining structure for the grease in the cam chamber 30 can be provided.
(Modification)
In the first embodiment, the case where the pin 24 that pivotally supports the planetary gear 21 is press-fitted into the press-fitting hole 29 to the position where it overlaps with the entire roller 27 is shown. However, as shown in FIG. A structure that partially overlaps the direction may be used.
[Brief description of the drawings]
FIG. 1 is a sectional view along an axial direction of a one-way clutch.
FIG. 2 is a cross-sectional view taken along the radial direction of the one-way clutch.
FIG. 3 is an overall view of a starter.
FIG. 4 is a sectional view taken along the axial direction of a one-way clutch (second embodiment).
FIG. 5 is a cross-sectional view along the axial direction of the one-way clutch (modified example).
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Starter 5 One-way clutch 21 Planetary gear 23 Outer 23A Outer cylindrical member 23B Inner cylindrical member 23a One wall part 23b The other wall part 24 Pin (support shaft)
27 Roller 29 Press-fit hole 30 Cam chamber

Claims (3)

A planetary gear reduction device for reducing the rotational speed of the motor;
An outer to which the rotation of the motor is transmitted through the planetary gear speed reducer, a roller housed in a cam chamber formed on the inner peripheral surface of the outer, and a rotation of the outer through the roller and a one-way clutch having an inner support shaft for supporting the planetary gears of the planetary gear reduction device to the outer is a starter is press-fitted,
The outer includes an outer cylindrical member and an inner cylindrical member that divide the press-fitting hole into which the support shaft is press-fitted in the radial direction, and the outer cylindrical member and the inner cylindrical member are fixed to each other by press-fitting. A characteristic starter. The support shaft, a starter according to claim 1, characterized by being press-fitted into the press-in hole so as to at least partially overlap before in the radial direction of kilometers over la. The outer cylindrical member has one wall portion that closes one side of the cam chamber along the axial direction of the support shaft,
The inner cylindrical member has the other wall portion that closes the other side of the cam chamber along the axial direction of the support shaft,
The starter according to claim 1 or 2, wherein the roller is restricted in movement in an axial direction by the one wall portion and the other wall portion.

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