JP2010007505A - Torque transmission device for starting engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque transmission device 1 for starting an engine capable of reducing cost by remarkably simplifying a heat treatment process. <P>SOLUTION: This torque transmission device 1 includes a first rotor 2 having a ring gear 7 at the whole periphery of the outermost diameter portion, a second rotor 4 rotatably assembled relative to the first rotor 2 through a rolling bearing 8 and fixed to the crankshaft 3 of the engine, a one-way clutch 5 intermitting torque transmission between the first rotor 2 and the second rotor 4 and the like. The clutch 5 is composed by using the outer ring 8a of the rolling bearing 8 as a clutch inner 5a to which the rotation of the first rotor 2 is transmitted, and the axial one end of the outer ring 8a is pressure-fitted and fixed to the inner periphery of the first rotor 2. Since only the ring gear 7 is subjected to induction hardening, the heat treatment process is remarkably simplified in comparison with an existing product. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an engine start torque transmission device in which a clutch is built in a ring gear of an engine and a starter driving torque is transmitted from the ring gear to the crankshaft of the engine via the clutch to start the engine.

In recent years, an idling stop system that automatically stops an engine when a signal stops at an intersection, for example, has been put into practical use as an exhaust gas countermeasure for automobiles, which is one of the causes of global warming. As a prior art employed in the system, there is a starter for an internal combustion engine described in Patent Document 1. The starting device includes a first rotating body having a ring gear provided on the outer periphery, a second rotating body (for example, a flywheel) fixed to the crankshaft of the engine, a first rotating body, and a second rotating body. And a one-way clutch disposed between the two.
When the engine is started, the drive torque of the starter is transmitted from the pinion gear to the ring gear, and the first rotating body having the ring gear rotates, whereby the rotation of the first rotating body is transmitted to the second rotating body via the clutch. Transmitted to crank the engine. On the other hand, when the rotation speed of the second rotating body exceeds the rotation speed of the first rotating body due to the start of the engine, the clutch is idled and torque transmission from the second rotating body to the first rotating body is interrupted. Is done.
JP 2000-274337 A

By the way, in the starter described above, a ring gear is formed at the outermost diameter portion of the first rotating body, and a clutch inner is provided at the innermost diameter portion of the first rotating body. The ring gear and the clutch inner are subjected to heat treatment (quenching) in order to improve wear resistance and fatigue resistance, but the types of quenching are different between the ring gear and the clutch inner. Specifically, carburizing quenching is performed on the clutch inner and induction hardening is performed on the ring gear. Explaining the heat treatment process, first, a carburizing agent is applied to the portion excluding the clutch inner (most part of the first rotating body including the ring gear), and then carburized and quenched in the clutch inner in a furnace in a gas atmosphere. I do. Thereafter, the previously applied carburizing agent is removed, and further, distortion generated in the first rotating body due to quenching in the furnace is removed, and then the ring gear is subjected to induction hardening. As described above, the structure of the starter according to the prior art has a problem that the heat treatment process is very complicated and the cost is increased accordingly.
The present invention has been made based on the above circumstances, and an object of the present invention is to provide an engine starting torque transmission device that can greatly simplify the heat treatment process and reduce the cost.

(Invention of Claim 1)
The present invention is an engine starting torque transmission device that transmits torque generated by a starter to an engine crankshaft, and includes a first rotating body having a ring gear that always meshes with a pinion gear of the starter, and the first rotating body. A second rotating body assembled so as to be relatively rotatable via a rolling bearing and connected to a crankshaft, and when the first rotating body is driven by a starter to rotate, the first rotating body is rotated to the second rotating body. A one-way clutch that transmits torque from the second rotating body to the first rotating body when the second rotating body rotates by being driven by the engine. The one-way clutch includes a clutch inner that rotates integrally with the first rotating body, a clutch outer that is disposed radially outside the clutch inner and rotates integrally with the second rotating body, And a clutch engaging member having a function of intermittently the transmission of torque between the Na and the clutch outer, characterized by using the outer ring of the rolling bearing on the clutch inner.

  For example, as an example of a rolling bearing, a ball bearing that is a JIS standard product is composed of a hard material (SUJ2 or the like) that has been heat-treated originally, so the outer ring of the ball bearing is used as a clutch inner. There is no need to perform a new heat treatment (carburizing and quenching). That is, the outer ring of the rolling bearing is not newly heat treated and can be used as it is as a clutch inner. On the other hand, the first rotating body having a ring gear does not need to be subjected to a charcoal-proofing process (a process of applying a carbon-proofing agent) on a portion excluding the ring gear, can be induction-hardened only on the ring gear, and the furnace Since it is not necessary to perform quenching in the inside, distortion associated with heat treatment does not occur. As a result, when compared with the conventional product in which the ring gear and the clutch inner are integrally provided on the first rotating body, the heat treatment process can be greatly simplified and the outer ring of the rolling bearing, which is conventionally a separate component, can be obtained. Since the number of parts can be reduced by sharing the clutch inner, the cost can be significantly reduced.

(Invention of Claim 2)
The engine start torque transmitting device according to claim 1, wherein the seal member is disposed on one end side in the axial direction of the clutch engagement element, and is fixed to the inner periphery of the clutch outer, and is in sliding contact with the outer peripheral surface of the outer ring of the rolling bearing. It is characterized by providing.
According to said structure, when compared with the case where a sealing member is arrange | positioned on the outer periphery of a clutch outer, the peripheral speed of the sliding contact surface which a sealing member slides can be made small, Therefore The durability of a sealing member can be improved. Further, since the seal member can be arranged closer to the clutch engagement element compared to the case where the seal member is arranged on the outer periphery of the clutch outer, the amount of lubricant (for example, grease) used in the clutch can be reduced, When expensive squalene is used for grease, the cost can be kept low.

(Invention of Claim 3)
3. The engine start torque transmitting device according to claim 1, wherein the outer ring of the rolling bearing has an other end side in the axial direction used as a clutch inner and an engagement member engaged with one end side in the axial direction. The first rotating body is fixed so as not to rotate relative to the first rotating body.
As an example of the engaging member, fixing with a key can be considered. That is, a key groove is formed in each of the contact surfaces (the inner peripheral surface of the first rotating body and the outer peripheral surface of the outer ring) where the first rotating body and the outer ring abut, and a key is inserted into both the key grooves. By inserting, the relative rotation between the first rotating body and the outer ring can be restricted.

(Invention of Claim 4)
The torque transmission device for starting an engine according to claim 1 or 2, wherein the outer ring of the rolling bearing has the other end in the axial direction as a clutch inner, and one end in the axial direction is on the inner periphery of the first rotating body. It is characterized by being press-fitted and fixed.
In this case, the first rotating body and the outer ring of the rolling bearing can be fixed easily and reliably only by appropriately setting the press-fitting allowance.

(Invention of Claim 5)
5. The engine starting torque transmission device according to claim 4, wherein the rolling bearing is provided such that one end side in the axial direction extends in the axial direction, and one end side in the axial direction of the outer ring including the extending portion is provided inside the first rotating body. It is characterized by being press-fitted and fixed around the circumference.
In this case, since the press-fitting length can be set longer, the fixing strength can be increased correspondingly, and deformation and distortion of the outer ring due to the press-fitting can be suppressed.

  The best mode for carrying out the present invention will be described in detail by the following examples.

FIG. 1 is a cross-sectional view of an engine starting torque transmission device (hereinafter abbreviated as torque transmission device 1) according to a first embodiment.
As shown in FIG. 1, the torque transmission device 1 of the present embodiment is driven by a starter (not shown) and rotates, and the first rotating body 2 and the axial direction (left and right in the drawing). And a clutch 5 provided between the first rotator 2 and the second rotator 4, and a second rotator 4 that is disposed close to the direction) and is fixed to the crankshaft 3 of the engine. The seal member 6 is configured to prevent the lubricant (for example, grease) used in the clutch 5 from flowing out.

The first rotating body 2 is provided in a disc shape, and a ring gear 7 is formed on the entire circumference of the outermost diameter portion. A starter pinion gear (not shown) is always meshed with the ring gear 7.
The second rotating body 4 is, for example, a flywheel for MT cars or a drive plate for AT cars, and is assembled with the first rotating body 2 via a rolling bearing 8 so as to be relatively rotatable. The second rotating body 4 is provided with a boss portion 4 a at the innermost diameter portion, a bolt 9 is passed through an axial through hole formed in the boss portion 4 a, and the bolt 9 is fastened to the crankshaft 3 to be fixed. Has been.
The rolling bearing 8 is a ball bearing in which a plurality of balls 8c are rotatably arranged between an outer ring 8a and an inner ring 8b, and one end in the axial direction of the outer ring 8a is press-fitted and fixed to the inner periphery of the first rotating body 2. Then, the inner ring 8b is fitted into the outer periphery of the boss portion 4a of the second rotating body 4 with a gap. Between the outer ring 8a and the inner ring 8b, seal plates 8d are respectively attached to both sides of the ball 8c in the axial direction so as to maintain sealing performance.

  The clutch 5 includes a clutch inner 5a that uses the outer ring 8a of the rolling bearing 8, a clutch outer 5b that is disposed on the radially outer side of the clutch inner 5a and is fixed to the second rotating body 4, a clutch inner 5a and a clutch A clutch engaging element 5c (for example, a roller, a sprag, a cam, etc.) that intermittently transmits torque to and from the outer 5b is formed. When the first rotating body 2 is driven by the starter and rotates, the clutch 5 is rotated by the outer ring 8a of the rolling bearing 8 fixed to the first rotating body 2, that is, the clutch inner 5a. The rotation of the clutch inner 5a is transmitted to the clutch outer 5b via the coupling 5c. On the other hand, when the second rotating body 4 is driven to rotate by the engine, the clutch engagement element 5c rotates idly between the clutch outer 5b and the clutch inner 5a, thereby causing torque from the clutch outer 5b to the clutch inner 5a. Block transmission.

  The seal member 6 is disposed between the clutch engagement element 5c and the first rotating body 2 in the axial direction, and its outer peripheral end is fixed to the inner periphery of the clutch outer 5b by press fitting or the like, and the inner peripheral end is a rolling bearing. By slidingly contacting the outer peripheral surface of the outer ring 8a, the space between the clutch outer 5b and the clutch inner 5a is hermetically sealed.

Next, the operation of the torque transmission device 1 will be described.
a) When starting the engine When the first rotating body 2 is driven and rotated by the starter, the clutch 5 enters an engaged state (a state where the clutch inner 5a and the clutch outer 5b are connected via the clutch engaging member 5c). Torque is transmitted in the order of first rotating body 2 → clutch 5 → second rotating body 4 → crankshaft 3 to start cranking.
b) After engine start The engine is completely exploded from cranking, and the rotation of the crankshaft 3 is transmitted to the second rotating body 4. The rotating speed of the second rotating body 4 is the rotating speed of the first rotating body 2. Is exceeded, the clutch 5 is idling and torque transmission from the second rotating body 4 to the first rotating body 2 is interrupted. Thereby, the rotation of the engine is not input to the starter side.

(Effect of Example 1)
The torque transmission device 1 of the present embodiment can obtain the following effects by using the outer ring 8a of the rolling bearing 8 as the clutch inner 5a.
For example, as an example of the rolling bearing 8, a ball bearing which is a JIS standard product is composed of a hard material (SUJ2 or the like) that is originally heat-treated. The clutch inner 5a does not need to be newly heat treated (carburized and quenched).

  On the other hand, the first rotating body 2 having the ring gear 7 does not need to be subjected to a charcoal-proofing process (a process of applying a carburizing agent) on the portion excluding the ring gear 7, and can be induction-hardened only on the ring gear 7. In addition, since it is not necessary to perform quenching in a furnace, there is no distortion caused by heat treatment. Thereby, when compared with the conventional product in which the ring gear 7 and the clutch inner 5a are integrally provided on the first rotating body 2, the heat treatment process can be greatly simplified, and in the past, rolling, which is a separate component in the past. By sharing the outer ring 8a of the bearing 8 and the clutch inner 5a, the number of parts can be reduced, so that the cost can be significantly reduced.

Further, the torque transmission device 1 according to the present embodiment has a structure in which the seal member 6 is disposed on one end side in the axial direction of the clutch engagement element 5c and hermetically seals between the clutch outer 5b and the clutch inner 5a. Compared with the case where the seal member 6 is arranged on the outer periphery of the clutch outer 5b, the peripheral speed of the slidable contact surface with which the seal member 6 slidably contacts can be reduced, so that the durability of the seal member 6 can be improved.
Further, since the seal member 6 can be disposed closer to the clutch engagement element 5c as compared with the case where the seal member 6 is disposed on the outer periphery of the clutch outer 5b, the amount of lubricant (for example, grease) used for the clutch 5 is increased. In particular, when expensive squalene is used for the grease, the cost can be kept low. The anti-seal member side of the clutch engagement element 5 c is sealed by the sealing function of the rolling bearing 8.

FIG. 2A is a cross-sectional view of the torque transmission device 1 according to the second embodiment.
In the first embodiment, an example in which the outer ring 8a of the rolling bearing 8 is press-fitted and fixed to the inner periphery of the first rotating body 2 is described. However, in the second embodiment, the outer ring 8a of the rolling bearing 8 is connected to one end side in the axial direction. The first rotating body 2 is fixed so as not to rotate relative to the first rotating body 2 through an engaging member that engages with the first rotating body 2.
As an example of the engaging member, for example, as shown in FIG. That is, a key groove is formed in each of the contact surfaces (the inner peripheral surface of the first rotating body 2 and the outer peripheral surface of the outer ring 8a) where the first rotating body 2 and the outer ring 8a are in contact with each other. By inserting the key 10 into the groove, the relative rotation between the first rotating body 2 and the outer ring 8a can be restricted.

FIG. 3 is a cross-sectional view of the torque transmission device 1 according to the third embodiment.
As in the first embodiment, the third embodiment is an example in which the outer ring 8a of the rolling bearing 8 is press-fitted and fixed to the inner periphery of the first rotating body 2, but the press-fitting length is increased. That is, as shown in FIG. 3, the rolling bearing 8 is provided such that one end side in the axial direction is extended in the axial direction, and one end side in the axial direction of the outer ring 8 a including the extending portion 8 e is the first rotating body 2. It is press-fitted and fixed to the inner circumference. In addition, the 1st rotary body 2 has the innermost diameter part formed in a cylindrical shape long in the axial direction corresponding to the extending part 8e of the rolling bearing 8, and ensures the press-fitting length with the extending part 8e.
According to the above configuration, since the press-fit length can be set longer than in the case of the first embodiment, the fixing strength can be increased correspondingly, and the deformation and distortion of the outer ring 8a due to the press-fit can be suppressed. Can do.

(Modification)
In the first embodiment, the seal member 6 is disposed on the inner peripheral side of the clutch outer 5b in the vicinity of one end side in the axial direction of the clutch engagement element 5c. For example, the outer side in the radial direction of the clutch outer 5b shown in FIG. A seal member (for example, an oil seal) can also be disposed in the space S formed in FIG.
Further, the rolling bearing 8 of the present invention need not be limited to a ball bearing, and for example, a roller bearing using a roller as a rolling element may be employed.

(Example 1) which is sectional drawing of a torque transmission apparatus. (A) Cross-sectional view of torque transmission device, (b) Cross-sectional view showing a method of fixing the first rotating body and the outer ring (Example 2). (Example 3) which is sectional drawing of a torque transmission device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine start torque transmission device 2 1st rotary body 3 Crankshaft 4 2nd rotary body 5 One-way clutch 5a Clutch inner 5b Clutch outer 5c Clutch engagement element 6 Seal member 7 Ring gear 8 Rolling bearing 8a Rolling bearing outer ring 8e Extending part of rolling bearing 10 Key (engaging member)

Claims (5)

An engine starting torque transmission device for transmitting torque generated by a starter to an engine crankshaft,
A first rotating body having a ring gear that always meshes with the pinion gear of the starter;
A second rotating body assembled to the first rotating body via a rolling bearing so as to be relatively rotatable, and connected to the crankshaft;
When the first rotating body rotates by being driven by the starter, torque is transmitted from the first rotating body to the second rotating body, and the second rotating body is driven by the engine to rotate. A one-way clutch that cuts off torque transmission from the second rotating body to the first rotating body,
The one-way clutch includes a clutch inner that rotates integrally with the first rotating body, a clutch outer that is disposed radially outside the clutch inner and rotates integrally with the second rotating body, and the clutch inner And an outer ring of the rolling bearing is used as the clutch inner. The torque transmission device for starting the engine has a clutch engaging member for interrupting transmission of torque between the clutch outer and the clutch outer. The torque transmission device for starting an engine according to claim 1,
An engine starting torque transmission comprising: a seal member disposed on one end side in the axial direction of the clutch engagement element, fixed to an inner periphery of the clutch outer, and slidably contacting an outer peripheral surface of an outer ring of the rolling bearing. apparatus. In the engine starting torque transmission device according to claim 1 or 2,
The outer ring of the rolling bearing is fixed to the first rotating body so as not to rotate relative to the first rotating body through an engaging member that is used as the clutch inner at the other end side in the axial direction and engages with one end side in the axial direction. A torque transmission device for starting an engine. In the engine starting torque transmission device according to claim 1 or 2,
The outer ring of the rolling bearing has an axial other end side used as the clutch inner, and an axial one end side is press-fitted and fixed to the inner periphery of the first rotating body. Torque transmission device. In the engine starting torque transmission device according to claim 4,
The rolling bearing is provided such that one end side in the axial direction extends in the axial direction, and one end side in the axial direction of the outer ring including the extending portion is press-fitted and fixed to the inner periphery of the first rotating body. Torque transmission device for starting the engine.

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