JPH0622644U - Flywheel for internal combustion engine - Google Patents

Abstract

(57) [Summary] [Purpose] An object of the present invention is to provide a flywheel that can prevent the ring gear from slipping even when the fitting force between the ring gear and the flywheel is reduced. A flywheel 1 for an internal combustion engine, in which a ring gear 3 is press-fitted on the outer circumference, wherein a stopper portion S having a straight portion 3b is formed on an inner circumferential arc surface 3a of the ring gear 3,
A recess 1b into which the stopper S fits is formed on the outer circumference of the flywheel 1.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 This invention relates to an improvement of a flywheel used in an internal combustion engine.

[0002]

[Prior art and its problems]

 2. Description of the Related Art Conventionally, a flywheel for an internal combustion engine has an engine-side crankshaft 2 connected to the center of a flywheel 1 as shown in FIG. A ring-shaped ring gear 3 having teeth formed therein is press-fitted and integrated by shrink fitting or the like, and this ring gear 3 is meshed with a gear of a starter. In such a flywheel 1, as shown in an exploded view in FIG. 6, a fitting step portion 1a is formed on the outer periphery of the flywheel 1, and the inner peripheral surface of the ring gear 3 is press-fit into the fitting step portion 1a. If the fitting state is good, the torque of the starter is satisfactorily transmitted from the flywheel 1 to the crankshaft 2 via the ring gear 3 when the starter is driven when the engine is started.

However, when the flywheel 1 is heated due to clutch slippage or the like and the flywheel 1 expands, the ring gear 3 is not expanded and plastically deformed. 3 is incompletely fitted, slippage occurs between the flywheel 1 and the ring gear 3, and the driving force of the starter is not properly transmitted to the crankshaft, which makes it difficult to start the engine. It was

[0004]

[Means for Solving the Problems]

 The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a flywheel in which the flywheel and the ring gear are firmly fitted to each other and which does not slip. The first gist is, in a flywheel for an internal combustion engine, in which a ring gear is press-fitted on the outer periphery, a stopper portion having a straight portion is formed on the inner peripheral arc surface of the ring gear, and the stopper portion is fitted. That is, the concave portion is formed on the outer circumference of the flywheel.

A second gist of the invention is a flywheel for an internal combustion engine in which a ring gear is press-fitted on the outer circumference, and the inner circumferential arc surface of the ring gear and the outer circumferential surface of the flywheel respectively correspond to corresponding positions. That is, a key groove is formed and a key is fitted into the key groove.

[0006]

[Action]

 When the stopper formed on the inner peripheral surface of the ring gear is press-fitted into the recess formed on the outer circumference of the flywheel, the straight portion of the stopper and the recess are tightly fitted, and the stopper causes the ring gear to move the flywheel. It prevents slipping around the outer periphery of the car, and the driving force of the starter is transmitted well to the flywheel via the ring gear.

In the second aspect, a key groove is formed on the inner peripheral surface of the ring gear and the outer peripheral surface of the flywheel, and the key is fitted into the key groove, so that the flywheel and the ring gear slide. Will be prevented by the key.

[0008]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a front view of a main part of the flywheel. A ring gear 3 is press-fitted on the outer circumference of the flywheel 1. However, a part of the inner circumferential arc surface 3a of the ring gear 3 is directed inward. The bulging stopper portion S is integrally formed, and the inner surface of the stopper portion S is a linear portion 3b. On the other hand, on the outer periphery of the flywheel 1, a recess 1b into which the stopper S can be fitted is formed in a part of the fitting step 1a in a recessed shape. The concave portion 1b has a linear portion corresponding to the linear portion 3b of the stopper portion S formed on the bottom surface.

The stopper portions S may be formed at two symmetrical positions on the inner circumferential arc surface 3a of the ring gear 3, or may be formed at four symmetrical positions. In this case, two or four recesses 1b are formed correspondingly on the flywheel 1 side.

As shown in FIG. 2, when the inner peripheral circular arc surface 3 a of the ring gear 3 is press-fitted onto the outer periphery of the fitting step portion 1 a of the flywheel 1 by means such as shrink fitting, it is inserted into the concave portion 1 b of the flywheel 1. Even if the stopper portion S of the ring gear 3 is fitted to prevent the ring gear 3 from slipping relative to the flywheel 1 and the press-fit state is poor and the fitting force between the flywheel 1 and the ring gear 3 is reduced, the recess 1b The ring gear 3 is prevented from slipping around the outer circumference of the flywheel 1 by the engagement of the stopper portion S with the stopper portion S, and when a starter (not shown) is driven, the driving force is transmitted from the ring gear 3 to the flywheel 1 well. By the way, the crankshaft connected to the flywheel 1 can be reliably rotated to start the engine, and the problems that have conventionally occurred can be solved well. You can

Next, FIG. 3 shows a second embodiment. As shown in FIG. 3, a key groove 1c is formed in a hollow shape on the outer circumference of the flywheel 1, and a ring gear corresponding to this key groove 1c is formed. A key groove 3c is formed in a concave shape on the inner circular arc surface 3a of 3 and the key 4 is driven into each key groove 1c, 3c with the key grooves 1c, 3c aligned with each other. The key 4 can prevent the ring gear 3 from slipping with respect to the flywheel 1. Even in such a structure, even if the fitting force between the flywheel 1 and the ring gear 3 is reduced, the ring gear 3 will not move. The drive force of the starter can be transmitted to the crankshaft side satisfactorily and reliably without slipping on the outer periphery of the crankshaft. The key grooves 1c and 3c can be formed at two or four symmetrical positions, and a key can be driven into each key groove to prevent the ring gear 3 from slipping more reliably.

[0012]

[Effect of device]

 According to the present invention, in a flywheel for an internal combustion engine in which a ring gear is press-fitted on the outer periphery, a stopper portion having a straight portion is formed on an inner circumferential arc surface of the ring gear, and a recess portion to which the stopper portion is fitted is formed. By forming the ring on the outer circumference of the flywheel, even if the fitting force between the flywheel and the ring gear is reduced, the recess of the outer circumference of the flywheel and the stopper of the ring gear fit together to ensure that the ring gear slips. In addition, the drive force of the starter can be reliably transmitted from the ring gear to the crankshaft of the engine via the flywheel, and the engine can be reliably started.

Further, in a flywheel for an internal combustion engine in which a ring gear is press-fitted on the outer periphery, key grooves are formed at corresponding positions on an inner peripheral arc surface of the ring gear and an outer peripheral surface of the flywheel, respectively. By fitting the key in the key groove, the key fitted in the key groove prevents the ring gear from slipping on the flywheel, and the drive force of the starter is reliably transmitted from the ring gear to the flywheel. Has the effect that can be done.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a flywheel according to a first embodiment.

FIG. 2 is an exploded side sectional view of a flywheel and a ring gear before they are fitted together.

FIG. 3 is a front view of a main part of a flywheel according to a second embodiment.

FIG. 4 is an exploded side cross-sectional configuration diagram of FIG. 3 before fitting.

FIG. 5 is a front view of a main part of a conventional flywheel.

FIG. 6 is an exploded side cross-sectional view before fitting of FIG.

[Explanation of symbols]

 1 Flywheel 1a Fitting step 1b Recesses 1c, 3c Key groove 3 Ring gear 3a Inner circular arc surface 3b Straight part 4 Key S Stopper part

Claims (2)

[Scope of utility model registration request] 1. A flywheel for an internal combustion engine in which a ring gear is press-fitted on the outer circumference, wherein a stopper portion having a linear portion is formed on an arcuate surface of the inner circumference of the ring gear, and a recess into which the stopper portion is fitted. A flywheel for an internal combustion engine, wherein a flywheel is formed on the outer periphery of the flywheel. 2. In a flywheel for an internal combustion engine, wherein a ring gear is press-fitted on the outer periphery, key grooves are formed at corresponding positions on an inner peripheral arc surface of the ring gear and an outer peripheral surface of the flywheel, respectively, and the key is formed. A flywheel for an internal combustion engine, characterized in that a key is fitted in the groove.