JPH04316745A - Fly wheel - Google Patents

Abstract

PURPOSE:To prevent the generation of an excessive impact force occasioned by the fluctuation in rotation of an engine by assembling a mass body to another mass body fixed on a crank shaft and locating a spring member, intercoupling two mass bodies when a centrifugal force exceeding a given value is exerted, between the two mass bodies. CONSTITUTION:During low speed rotation wherein the number of revolutions of an engine attains in short of the number of idle revolutions, a centrifugal force exerted on a compression coil spring 20 of a spring member 17 is lower than the spring force of a tension coil spring 19, and the compression spring 20 is located in a spring receiving part 16 of an output member 12. Thus, second mass bodies 2 and 3 are integrally rotated by means of a frictional force generating means 24. Meanwhile, the number of revolutions of an engine attains the given number of revolutions approximately equal to the number of idle revolutions and a centrifugal force is increased to a value higher than the spring force of a tension spring 19, the compression coil spring 20 is radially slid within the spring receiving part 16 and engaged with a spring receiving part 9 of a retainer 10, the two mass bodies 2 and 3 are resiliently intercoupled through the compression coil spring 20, and impulsive rotation is relaxed.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flywheel attached to the end of a crankshaft.

0002

[Prior Art] This type of flywheel reduces rotational fluctuations of the crankshaft due to fluctuations in engine torque, damps torsional vibrations of the crankshaft, and enables smooth power transmission to the output shaft via the clutch. Various efforts have been made to do so.

For example, in the flywheel disclosed in Japanese Utility Model Publication No. 2-6285, as shown in FIG.
At the same time, a centrifugal clutch 104 is interposed between both mass bodies 101 and 102,
05) is in a low rotation range where the engine rotation speed does not reach the idle rotation speed, the centrifugal clutch 104 rotates both mass bodies 101 and 102 together to avoid resonance, while the engine rotation speed exceeds a predetermined rotation speed. When the engine reaches a normal rotation range above idle rotation, the centrifugal clutch 104 is unlocked by centrifugal force (the state shown in FIG. 5), and the torsional damper 103 elastically connects the mass bodies 101 and 102. to suppress rotational fluctuations.

0004

[Problems to be Solved by the Invention] However, in such conventional examples, when the engine speed drops to a low speed range that does not reach the idle speed, the centrifugal clutch 1
Since the elastic force of the spring 106 of 04 becomes larger than the centrifugal force acting on the lock pin 107, both mass bodies 101 and 102 rotate relative to each other by a predetermined angle (θ/2) from the neutral position N as the engine torque fluctuates. When the lock pin 107 is biased radially inward by the spring 106, the lock pin 107 moves into the lock groove 108.
The two mass bodies 101 and 102 are rotated together.

Therefore, when both mass bodies 101 and 102 are integrated by centrifugal clutch 104, both mass bodies 1
The torsional damper (compression coil spring) 103 that connects 01 and 102 is in a compressed state. This state is maintained when the engine speed is below a predetermined number of revolutions or when the engine is stopped, so the torsional
Compressive force will be applied to the damper 103 for a long time, and there is concern that the function of the torsional damper 103 will deteriorate over time.

[0006] The present invention aims to eliminate such problems of the conventional example.

[0007]

[Means for Solving the Problems] That is, the flywheel of the present invention has a mass body divided into parts, one mass body being fixed to a crankshaft, and the other mass body being able to rotate relative to this mass body. and form spring receivers at corresponding positions on both of these mass bodies, and when a centrifugal force of a predetermined amount or more is applied to one of these spring receivers, the spring moves within the spring receiver. It is characterized by housing a spring member that also engages with the other spring receiving portion and elastically connects both the mass bodies.

[0008]

[Operation] Not only when the engine (crankshaft) is stopped, but also in the low-speed rotation range where the engine speed does not reach the idle speed, when the centrifugal force acting on the spring member does not reach the specified level, the spring member Since the bodies are not connected, the spring member is not subjected to excessive compression force or excessive impact force due to fluctuations in engine rotation.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a sectional view of a flywheel installed according to an embodiment of the present invention, and in this figure, reference numeral 1 indicates a crankshaft. A first mass body 2 and a reinforcement plate 3 are fixed to the shaft end of the crankshaft 1 with bolts 4. The first mass body 2 includes a substantially disk-shaped elastic plate 5 whose inner peripheral end is fixed to the crankshaft 1.
A ring gear 6 and a side plate 7 are fitted to the outer peripheral end of the elastic plate 5, and an operating chamber 8 is formed between the elastic plate 5 and the side plate 7. A retainer 10 is provided with a spring receiving portion 9 on the outer peripheral side within the working chamber 8.
The retainer 10 is fixed to the elastic plate 5 and the side plate 7 with bolts 11, respectively.

12 is an output member. This output member 12
The plate portion 13 is engaged with the elastic plate 5 so as to be relatively rotatable, and the boss portion 14 is rotatably supported by a bearing 15 attached to the reinforcement plate 3. Further, the plate portion 13 of the output member 12 has a spring receiving portion 16 corresponding to the spring receiving portion 9 of the retainer 10.
A spring member 17 is housed in the spring receiving portion 16 so as to be slidable in the radial direction (vertical direction in FIG. 1).

This spring member 17 is composed of a tension spring 19 whose one end is fixed to the bottom wall 18 of the spring receiving part 16 by welding or the like, and a compression coil spring 20 which is fixed to the other end of this tension spring 19 by welding or the like. (See Figure 2). When a centrifugal force of a predetermined value or higher is applied to the spring member 17, the compression coil spring 20 slides within the spring receiving portion 16 against the spring force of the tension spring 19, and as shown in FIGS. It also engages with the spring receiving part 9 of.

As shown in FIGS. 2 and 4, the circumferential length of the spring receiving portion 9 formed on the retainer 10 is the same as that of the output member 1.
The circumferential length of the second spring receiving portion 16 is slightly larger than that of the second spring receiving portion 16 . Therefore, as shown in FIG.
When the output member 12 and the output member 12 rotate slightly relative to each other, the first mass body 2 and the output member 12 are elastically connected by the spring member 17.

A disc-shaped member 21 is fixed to the boss portion 14 of the output member 12 with bolts 22, and this disc-shaped member 21 and the output member 12 constitute a second mass body 23. .

24 is a friction force generating means. The frictional force generating means 24 is interposed between the elastic plate 5 and the output member 12, and includes a friction plate 25, a retainer plate 26, and a disc spring 27. This frictional force generating means 24 is configured to connect the first mass body 2 and the second mass body 23.
Both mass bodies 2, 23 are rotated together unless a rotational force exceeding a predetermined value acts on either one of them, while both mass bodies 2, 2
When a rotational force of more than a predetermined value is applied to either one of the mass bodies 2 and 3, the two mass bodies 2 and 23 are allowed to rotate relative to each other. Incidentally, this friction force generating means 24 is configured to act on the friction plate 2 when both the mass bodies 2 and 23 rotate relative to each other.
Frictional resistance is generated at the sliding contact surface between the elastic plate 5 and the elastic plate 5, thereby damping torsional vibration of the crankshaft system.

28 is the second mass body 23 of the flywheel A.
The clutch disk 28 is frictionally engaged with the clutch disk 28, and the boss portion 29 of the clutch disk 28 is spline-fitted to the output shaft 30. 31 is the second flywheel A.
This is a clutch cover assembly attached to a mass body 23. The ring gear 6 is meshed with a pinion gear of a starter motor (not shown).

According to the structure of the embodiment described above, when the engine rotation speed (the rotation speed of the crankshaft 1) is at a low speed that does not reach the idle rotation speed, the centrifugal force acting on the compression coil spring 20 of the spring member 17 causes tension. The compression coil spring 20 is smaller than the spring force of the coil spring 19 and is located within the spring receiving portion 16 of the output member 12 (see FIGS. 1-2). In this case, the first mass body 2 and the second mass body 23 are rotated together by the frictional force generating means 24. Generally, the resonance point of the torsional vibration of the crankshaft system is set at an engine rotation speed lower than the idle rotation speed. Therefore, even if excessive torque is input to the flywheel A at an engine speed near the resonance point of the torsional vibration, the frictional force generating means 24 will slip, causing the first mass body 2 and the second mass body 23 to slip. rotates relative to each other without compressing the compression coil spring 20. Therefore, excessive impact force due to engine rotational fluctuations does not act on the spring member 17.

When the engine speed reaches a predetermined speed near the idle speed and the centrifugal force acting on the compression coil spring 20 of the spring member 17 becomes larger than the spring force of the tension spring 19, the compression coil spring 20 becomes the output member. The first mass body 2 and the second mass body 2
3 are elastically connected by a compression coil spring 20 (see FIGS. 3 and 4). As a result, when the first mass body 2 and the second mass body 23 rotate relative to each other due to engine rotational fluctuations, the impact force due to the engine rotational fluctuations is buffered by the spring member 17, and torsional vibration is suppressed by the frictional force generating means. 24. As a result, engine power is smoothly transmitted to the output shaft 30 via the crankshaft 1, flywheel A, and clutch disc 28.

[0019]

Effects of the Invention As is clear from the above description, the flywheel of the present invention has a mass body divided into parts, one mass body fixed to the crankshaft, and the other mass body rotated relative to this mass body. These mass bodies are assembled in a movable state, and spring receiving parts are formed at corresponding positions of both of these mass bodies, and when a centrifugal force of a predetermined amount or more is applied to one of these spring receiving parts, the inside of that spring receiving part is Since the spring member moves and engages with the other spring receiving part and elastically connects the two mass bodies, excessive impact force is prevented when the engine is stopped or due to fluctuations in engine rotation. In the low-speed rotation range where the input speed is input, no excessive compressive force or impact force is applied to the spring member. Therefore, according to the flywheel of the present invention, the durability of the spring member is improved, and the desired function of the flywheel is exhibited over a long period of time.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a flywheel in an attached state showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB in FIG. 1;

FIG. 3 is a sectional view of the flywheel showing the operating state of the spring member.

FIG. 4 is a sectional view taken along line CC in FIG. 3;

FIG. 5 is a sectional view of main parts of a conventional flywheel.

[Explanation of symbols]

A... Flywheel, 1... Crankshaft, 2... Mass body (first mass body), 9, 16... Spring receiver, 17... Spring member, 23... Mass body (second mass body).

Claims (1)

[Claims] Claim 1: A mass body is divided, one mass body is fixed to a crankshaft, and the other mass body is assembled to this mass body in a relatively rotatable state, and the two mass bodies are placed at corresponding positions. A spring receiving portion is formed, and when a centrifugal force of a predetermined amount or more is applied to one of these spring receiving portions, the spring receiving portion moves within the spring receiving portion and engages with the other spring receiving portion. A flywheel characterized by housing a spring member that elastically connects both mass bodies.