JP2005180634A - Pulley unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pulley unit which can reduce a machining time for a sleeve and a machining cost. <P>SOLUTION: The pulley unit 20 comprises a fitting portion 40 on the inner peripheral surface of the sleeve 22, the output shaft 62 of a starter motor being fitted in the fitting portion 40, a machined portion 42 which serves for the datum in machining and the datum for positioning in mounting the pulley unit on the starter motor, and a roughly machined portion 41 having the machining accuracy lower than that of the machined portion 42 for the datum. The machined portion 42 for the datum and the roughly machined portion 41 are arranged between the fitting portion 40 and one end 22a of the sleeve 22 in the axial direction. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pulley unit, and more particularly to a pulley unit that is preferably used in a starter for starting an engine in an automobile with an idling stop function.

  As a conventional pulley unit, one that is applied to an alternator that is driven by the rotational driving force of a crankshaft of an automobile engine is known (for example, see Patent Document 1).

  As shown in FIG. 4, the pulley unit 1 disclosed in Patent Document 1 is arranged concentrically with the sleeve 2 that can be fitted and fixed to a rotating shaft (not shown) of an alternator, and is arranged on the outer peripheral surface. A pulley 3 on which an endless belt (not shown) is suspended. A roller clutch 4 and a pair of support bearings 5 and 5 are provided at both ends between the outer peripheral surface of the sleeve 2 and the inner peripheral surface of the pulley 3.

  The pair of support bearings 5 and 5 make the relative rotation of the pulley 3 and the sleeve 2 freely while supporting a radial load applied to the pulley 3. In the illustrated example, deep groove type ball bearings are used as the support bearings 5 and 5.

  The roller clutch 4 includes a clutch outer ring 6 that is fitted and fixed at a predetermined position on the inner diameter surface of the pulley 3, and a clutch inner ring 7 that is fitted and fixed at a predetermined position on the outer diameter surface of the sleeve 2. In consideration of the use conditions and purpose of use of the clutch, cam surfaces 8 are formed on the outer peripheral surface of the clutch inner ring 7 at equal intervals in the circumferential direction, and between the inner peripheral surface of the clutch outer ring 6 and the cam surface 8. A plurality of rollers 9 are disposed on the side.

  The plurality of rollers 9 are supported by a roller holder 10 that rotates together with the clutch inner ring 7 such that the rollers 9 can be slightly displaced in the rolling and circumferential directions. Further, a spring (not shown) is provided between the column portion provided on the roller holder 10 and each roller 9. Each of these springs directs each roller 9 to a portion of the cylindrical gap formed between the outer peripheral surface of the cam surface 8 and the intermediate inner peripheral surface of the clutch outer ring 6 that has a reduced diametric width. The roller retainer 10 is elastically pressed in the circumferential direction.

  Further, the roller retainer 10 restricts movement in the width direction by extending portions 11, 11 formed radially inward at both axial ends of the clutch outer ring 6. Therefore, the roller holder 10 is restricted from moving in the axial direction by the extending portion 11 and is maintained at an appropriate position inside the clutch. Further, since the roller 9 and the spring are held by the cage 10, the roller 9 and the cam surface 8 are kept at appropriate positions, and stable engagement and idling (overrun) performance can be ensured.

In order to attach the pulley unit 1 to the shaft of the alternator for DC power generation, a hexagonal hole portion 12 for tool insertion, a screw portion 13 for fitting with the shaft of the alternator, and a sleeve on the inner peripheral surface of the sleeve 2 2 and a reference processing portion 14 which is used as a reference at the time of attachment to the alternator shaft. In order to use the reference processing portion 14 as a reference portion at the time of processing and attachment, relatively strict values are set for the dimensional tolerance of the hole diameter and the finishing degree (surface roughness). For example, the hole diameter dimensional tolerance is set to H7, and the finished surface roughness is set to Ra 1.6.
JP 2001-271853 A (page 2-6, FIG. 1)

  However, in Patent Document 1, the reference processing portion 14 in the sleeve 2 of the pulley unit 1 has high processing accuracy (for example, dimensional tolerance: 7, finish surface roughness: Ra 1.6) over the entire axial direction. Once set, the alternator shaft is attached to the sleeve 2. For this reason, if it is attempted to ensure the processing accuracy of the reference processing portion 14 over the entire axial direction, there is a risk that an increase in processing time, that is, an increase in processing cost, occurs as the processing depth increases.

  Further, when the pulley unit is used in a belt type starter motor for starting the engine, the axial length of the sleeve may be extended due to the structure on the starter motor side. Even in the case of the sleeve having the axial length extended as described above, if it is attempted to ensure the processing accuracy of the reference processing portion over the entire axial direction, the processing time may be further increased and the processing cost may be increased. .

  This invention is made | formed in view of the said situation, The objective is to provide the pulley unit which can aim at reduction of the processing cost in a sleeve.

The above object of the present invention is achieved by the following configurations.
(1) A starter motor side motor pulley and an engine side crank pulley are connected by a belt, and the rotational force of the starter motor is transmitted from the motor pulley to the crank pulley via the belt to be used in a starter for starting the engine. Pulley unit,
A sleeve arranged concentrically with the motor pulley and into which the output shaft on the starter motor side is inserted;
A one-way clutch for transmitting rotation of the output shaft on the starter motor side to the motor pulley;
A support bearing disposed at both ends of the one-way clutch and supporting a radial load applied to the motor pulley;
With
The one-way clutch is rotated with the cam surface formed on the inner peripheral surface of the clutch outer ring or the outer peripheral surface of the clutch inner ring, and the clutch outer ring or the clutch inner ring formed with the cam surface, and the cam is A roller clutch having a roller retainer for holding it at an appropriate position on the surface,
On the inner peripheral surface of the sleeve, a fitting portion in which the output shaft on the starter motor side is fitted, and a reference processing portion that serves as a reference for processing and serves as a positioning reference for attachment to the starter motor And a simple machining portion having a machining accuracy lower than that of the reference machining portion,
The pulley unit, wherein the reference processing portion and the simplified processing portion are disposed between the fitting portion and one end of the sleeve in the axial direction.
(2) The pulley unit according to (1), wherein an inner peripheral surface of the sleeve has the simplified processed portion on both sides of the fitting portion.

  According to the pulley unit of the present invention, on the inner peripheral surface of the sleeve, the fitting portion into which the output shaft on the starter motor side is fitted, the reference for processing, and the positioning reference for mounting with the starter motor And a simple processing portion having a surface roughness lower than that of the reference processing portion, and the reference processing portion and the simple processing portion are provided between the fitting portion and one end of the sleeve in the axial direction. Placed in. Therefore, it is not necessary to perform high-precision processing over the entire axial direction between the fitting portion and one end of the sleeve. As a result, the processing time can be shortened and the processing cost can be greatly reduced, so that the problem of an increase in processing cost due to an increase in processing time accompanying an increase in processing depth can be solved. The processing cost of the sleeve can be reduced.

  In addition, in the case where there are simple processing portions on both sides of the fitting portion, not only the reference processing portion but also the axial length of the hole for tool insertion that requires high processing accuracy can be shortened. The processing time can be shortened and the processing cost can be reduced.

  Hereinafter, a pulley unit according to each embodiment of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a partial cross-sectional view showing a state in which a pulley unit according to the present invention is incorporated in a starter of an automobile engine, and FIG. 2 is a cross-sectional view showing the pulley unit of the first embodiment.

  As shown in FIG. 1, the pulley unit 20 according to the first embodiment of the present invention connects a motor pulley 21 on the starter motor side and a crank pulley 70 on the engine side with an endless belt 80, and the rotational force of the starter motor 60 is Is transmitted from the motor pulley 21 to the clan pulley 70 via the endless belt 80, and used for a starter for starting the engine 71.

  The pulley unit 20 includes a motor pulley 21 and a sleeve 22 arranged concentrically with the motor pulley 21 inside the motor pulley 21. An endless belt 80 is suspended on the outer peripheral surface of the motor pulley 21 and is connected to a crank pulley 70 fixed to the end of the crankshaft 72 of the engine 71. Further, the sleeve 22 is inserted with the tip of the output shaft 62 of the speed reducer 61 connected to the output shaft on the starter motor side, specifically, the output shaft (not shown) of the starter motor 60.

  The rotational driving force of the starter motor 60 is increased (decelerated) by the speed reducer 61 and transmitted to the sleeve 22 as the rotational driving force of the output shaft 62. In addition, as such a reduction gear 61, the thing of various structures, such as a planetary gear type, can be used.

  The pulley unit 20 is a roller clutch 23 that is a one-way clutch of the present invention that transmits the rotation of the output shaft 62 on the starter motor side to the motor pulley 21 between the inner peripheral surface of the motor pulley 21 and the outer peripheral surface of the sleeve 22. And a pair of support bearings 24, 24 disposed at both ends of the roller clutch 23 in the axial direction.

  As shown in FIG. 2, the pair of support bearings 24, 24 supports a radial load applied to the motor pulley 21, while allowing relative rotation between the motor pulley 21 and the sleeve 22. In this embodiment, a deep groove ball bearing is used. I use it. Each support bearing 24 is rotatably provided between an outer ring 25 having an outer ring raceway 25a on the inner peripheral surface, an inner ring 26 having an inner ring raceway 26a on the outer peripheral surface, and a plurality of each between the outer ring raceway 25a and the inner ring raceway 26a. Ball 27 which is a rolling element. The outer ring 25 is fitted and fixed to the inner peripheral surface near the both ends of the motor pulley 21, and the inner ring 26 has both ends in the axial direction of the large-diameter portion 28 having a larger diameter than the other part formed in the intermediate portion in the axial direction of the sleeve 22. The sleeve 22 is fitted to the outer peripheral surface near the both ends while being in contact with the surface (step surface).

  Further, the support bearing 24 includes seal rings 29 and 29 for preventing leakage of the lubricant filled in the space where the roller clutch 23 and the support bearings 24 and 24 are installed.

  The roller clutch 23 includes a clutch inner ring 30 that is fitted and fixed to the large-diameter portion 28 of the sleeve 22 by an interference fit, and a clutch outer ring 31 that is fitted and fixed to the intermediate portion of the inner peripheral surface of the motor pulley 21 by an interference fit. Yes. On the inner peripheral surface of the clutch outer ring 31, a cam surface 32 is formed in which a plurality of cam recesses are formed at equal intervals in the circumferential direction. A plurality of rollers 33 are arranged in a wedge space formed between the outer peripheral surface of the clutch inner ring 30 and the cam surface 27.

  Further, between the outer peripheral surface of the clutch inner ring 30 and the inner peripheral surface of the clutch outer ring 31, there is a roller retainer 34 that rotates around the clutch outer ring 31 by engaging the outer peripheral edge with a part of the cam surface 32. Is provided. The roller 33 is held at an appropriate position on the cam surface 32 by the roller holder 34 and is supported so as to be slightly displaceable in the rolling and circumferential directions. In addition, a spring (not shown) is provided between the roller holder 34 and the roller 33 in the circumferential direction to press the roller 33 in a direction in which the cam recess is shallow.

  The inner peripheral surface of the sleeve 22 has a shaft hole 37 into which the output shaft 62 of the speed reducer 61 that is the output shaft on the starter motor side of the present invention is fitted. A tool hole portion 38 for tool insertion, a simplified processing portion 39, and an output shaft 62 on the starter motor side are fitted into the shaft hole 37 from the left side to the right side in FIG. A female thread portion 40 that is a fitting portion, a simplified processing portion 41, and a reference processing portion 42 are sequentially formed.

  The tool hole 38 is formed in a hexagonal hole shape that approximates the outer shape of the tool to be inserted, and a tool (not shown) is inserted when the pulley unit 20 is assembled to the output shaft 62 on the starter motor side. Used for The hole shape of the tool hole portion 38 is a hole shape corresponding to the serration shape when the tool is, for example, a shaft shape with serration.

  The female screw portion 40 is standardized so that a male screw (not shown) formed on the output shaft 62 of the speed reducer 61 is screwed.

  The reference processing section 42 serves as a reference when the sleeve 22 is processed, and serves as a positioning reference when the output shaft on the starter motor side, that is, the output shaft 62 of the speed reducer 61 is attached. The reference processing portion 42 is finished by cutting and finishing so that the dimensional tolerance of the hole diameter is H7 and the finished surface roughness is Ra 1.6.

  The simple processing portions 39 and 41 are arranged on both sides of the female screw portion 40, are finished with a minimum required processing accuracy, and have a surface roughness lower than that of the reference processing portion. When the sleeve 22 is created by forging, the simplified machining portions 39 and 41 are created by omitting cutting.

  The sleeve 22 is provided extending in the axial direction so as to protrude from one end of the motor pulley 21 toward the starter motor, and the reference processing portion 42 extends from the end portion 40 a of the female screw portion 40. It is partially formed in the axial direction length L1 between the one end 22a. That is, the reference processing portion 42 is formed over a portion having an axial length L2 shorter than the axial length L1, and a simplified processing portion 39 is formed in the remaining portion of the axial length L1. Yes.

  Therefore, the reference processing portion 42 and the simplified processing portion 41 are provided between the end portion 40a of the female screw portion 40 and the one end 22a of the sleeve 22, and the reference processing portion 42 that requires high processing accuracy is axially long. It is not necessary to provide the entire length L1, so that the processing time can be shortened and the processing cost can be reduced.

  Further, the shaft hole 37 of the sleeve 22 has a larger inner diameter D2 of the reference processing portion 42 than an inner diameter D1 of the simplified processing portion 41. Thus, after finishing with the minimum required processing accuracy over the axial length L1, the reference processing portion 42 may be processed in the axial length L2, so that the reference can be performed without using a complicated process. The processing part 42 can be created. Further, when the simplified processing portion 41 is created by forging, it is only necessary to process the reference processing portion 42, so that the processing time can be shortened and the processing cost can be reduced.

  Further, the shaft hole 37 of the sleeve 22 is provided with a simple processing portion 39 which is processed with a minimum necessary shape, size and accuracy between the tool hole portion 38 and the female screw portion 40 in the axial direction. As a result, the axial length of the tool hole 38 requiring high machining accuracy can be shortened, and the machining time can be further shortened, and the machining cost can be reduced.

  When such a pulley unit 20 is assembled to the output shaft 62 of the speed reducer 61, a tool is inserted into the tool hole 38, and the female screw portion 40 of the sleeve 22 is engaged with the male screw of the output shaft 62 while turning the tool. While aligning, the sleeve 22 is advanced to the output shaft 62, and the reference processing portion 42 of the sleeve 22 is extrapolated to the outer peripheral surface of the output shaft 62. Thereby, the pulley unit 20 is positioned concentrically with the output shaft 62.

  In an automobile having an idling stop function in which the pulley unit 20 configured as described above is incorporated, when the engine 71 is automatically stopped based on a vehicle speed zero signal detected by the vehicle speed sensor and the vehicle restarts. The engine 71 is automatically restarted based on a signal from a clutch sensor that detects the movement of the clutch pedal (in the case of a manual transmission vehicle) or an accelerator sensor that detects the movement of the accelerator pedal (in the case of an automatic transmission vehicle).

  When the engine 71 is restarted, when the output shaft 62 of the speed reducer 61 is rotationally driven by the starter motor 60, the roller clutch 23 is engaged, and the rotational force is transmitted from the output shaft 62 to the crankshaft 72. The rotation can be transmitted to the engine 71. On the other hand, when the engine 71 is restarted and the rotational speed of the crankshaft 72 becomes faster than the rotational speed of the output shaft 62, the roller clutch 23 is idled to prevent transmission of rotational force to the output shaft 62, and the engine that has started The rotation of 71 is prevented from being transmitted to the starter motor 60. Thus, by incorporating the pulley unit 20 of the present embodiment into a vehicle having an idling stop function, the time lag between the start of the operation for restarting the vehicle and the restart of the engine 71 is reduced. be able to.

  According to the pulley unit 20 of the first embodiment, the inner peripheral surface of the sleeve 22 is provided with a female screw portion 40 in which the output shaft 62 on the starter motor side is fitted, a reference for processing, and the starter motor. A reference processing portion 42 that serves as a positioning reference at the time of attachment and a simplified processing portion 41 having a surface roughness lower than that of the reference processing portion 42 are provided. The reference processing portion 42 and the simplified processing portion 41 are arranged in the axial direction. In FIG. 3, the internal thread portion 40 and the one end 22a of the sleeve 22 are disposed. Therefore, it is not necessary to perform highly accurate processing over the entire axial direction between the end portion 40a of the female screw portion 40 and the one end 22a of the sleeve 22. As a result, the processing time can be shortened and the processing cost can be greatly reduced, so that the problem of an increase in processing cost due to an increase in processing time accompanying an increase in processing depth can be solved. The processing cost of the sleeve 22 can be reduced.

  Further, according to the pulley unit 20 of the first embodiment, even if the sleeve 22 is extended in the axial direction due to the structure on the starter motor side, the reference processing portion 42 is connected to the end portion 40a of the female screw portion 40 and the sleeve 22. Since it is a part of the axial length L1 between the one end 22a, the reference processing portion 42 that requires high processing accuracy can be shortened regardless of the axial length of the sleeve, and the processing time can be shortened. The processing cost can be reduced.

  Further, according to the pulley unit 20 of the first embodiment, since the inner diameter D2 of the reference processing portion 42 is larger than the inner diameter D1 of the simplified processing portion 42, the minimum required processing accuracy over the axial length L1. Since the reference processing portion 42 has only to be processed in the portion having the axial length L2 after finishing in step S1, the reference processing portion 42 can be created without using a complicated process.

  Furthermore, according to the pulley unit 20 of the first embodiment, since the simplified processing portions 39 and 41 are provided on both sides of the female screw portion 40, not only the reference processing portion 42 but also the tool hole portion 38 that requires high processing accuracy. The length in the axial direction can also be shortened, and the processing time can be further reduced and the processing cost can be reduced.

(Second Embodiment)
Next, the pulley unit of 2nd Embodiment is demonstrated with reference to FIG. FIG. 3 is a cross-sectional view showing the pulley unit of the second embodiment. Note that the same or equivalent parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted or simplified.

  As shown in FIG. 3, the pulley unit 50 of the second embodiment includes a reference processing portion 51 having an inner diameter D <b> 3 that is smaller than the inner diameter D <b> 1 of the simplified processing portion 41. The reference processing portion 51 is a reference for processing and a positioning reference for mounting with the starter motor 60, and has a hole diameter dimensional tolerance of H7 and a finished surface roughness of Ra 1.6. Finished by processing and finishing. Other configurations are the same as those of the first embodiment.

  Therefore, according to the pulley unit 50 of the second embodiment, the size of the inner diameter D3 of the reference processing portion 51 can be set according to the outer diameter of the output shaft 62 on the starter motor side, and such a positional relationship In this case, it is not necessary to provide the reference processing portion 51 over the entire axial length L1 of the end portion 40a of the female screw portion 40 and the one end 22a of the sleeve 22, and the same effect as that of the first embodiment can be obtained. .

In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.
In this embodiment, the cam surface is formed on the inner peripheral surface of the clutch outer ring. However, the present invention is not limited to this, and the cam surface may be applied to a one-way clutch in which the cam surface is formed on the outer peripheral surface of the clutch inner ring. it can.
Further, the reference processed portion and the simplified processed portion may have the same inner diameter, and the surface roughness on one side may be finely formed, and that portion may be used as the reference processed portion.
In addition, the length of the reference processing part and the simple processing part is selected and set according to the conditions under which the pulley unit is used, but if the mounting accuracy may be low, the length of the reference processing part is set. You may shape | mold short.
Further, the roller clutch can be provided directly between the motor pulley and the output shaft of the starter motor without using a reduction gear.
The support bearing is not limited to the deep groove ball bearing, and various rolling bearings such as an angular ball bearing and a cylindrical roller bearing may be applied.

It is a fragmentary sectional view showing the state where the pulley unit concerning the present invention was built in the starter of the engine for vehicles. It is sectional drawing which shows the pulley unit of 1st Embodiment. It is sectional drawing which shows the pulley unit of 2nd Embodiment. It is sectional drawing of the conventional pulley unit.

Explanation of symbols

20, 50 Pulley unit 21 Motor clutch 22 Sleeve 23 Roller clutch (one-way clutch)
24 Support bearing 30 Clutch inner ring 31 Clutch outer ring 32 Cam surface 33 Roller 34 Roller retainer 38 Tool hole 39, 41 Simplified machining part 40 Female thread part (fitting part)
42,51 Reference processing part 60 Starter motor 70 Crank pulley 71 Engine 80 Endless belt

Claims (2)

A pulley unit used in a starter for starting the engine by connecting a motor pulley on the starter motor and a crank pulley on the engine side with a belt, and transmitting the rotational force of the starter motor from the motor pulley to the crank pulley via the belt. Because
A sleeve arranged concentrically with the motor pulley and into which the output shaft on the starter motor side is inserted;
A one-way clutch for transmitting rotation of the output shaft on the starter motor side to the motor pulley;
A support bearing disposed at both ends of the one-way clutch and supporting a radial load applied to the motor pulley;
With
The one-way clutch is rotated with the cam surface formed on the inner peripheral surface of the clutch outer ring or the outer peripheral surface of the clutch inner ring, and the clutch outer ring or the clutch inner ring formed with the cam surface, and the cam is A roller clutch having a roller retainer for holding it at an appropriate position on the surface,
On the inner peripheral surface of the sleeve, a fitting portion into which the output shaft on the starter motor side is fitted, and a reference processing portion that serves as a reference for processing and serves as a positioning reference for attachment to the starter motor And a simple processing portion having a lower surface roughness than the reference processing portion,
The pulley unit, wherein the reference processing portion and the simplified processing portion are disposed between the fitting portion and one end of the sleeve in the axial direction.   2. The pulley unit according to claim 1, wherein an inner peripheral surface of the sleeve has the simplified processed portion on both sides of the fitting portion.

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