JPH0126414B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a power transmission mechanism for an automobile that transmits power from a crankshaft of an internal combustion engine to a main drive shaft of a transmission.

Generally, the crankshaft of an automobile internal combustion engine is subjected to three types of vibration: torsional vibration, bending vibration, and longitudinal vibration.

Of these vibrations, we particularly reduce torsional vibration,
Conventionally, a rigid flywheel has been fixed to the crankshaft in order to achieve smooth rotation, but this flywheel cannot sufficiently reduce the torsional vibration. Therefore, for example, by interposing a torsion spring between the clutch disk and the clutch hub, a torsion spring mechanism consisting of a compression coil spring or the like is connected from the crankshaft to the main drive of the transmission so as to act elastically in the torsional direction. These torsional vibrations are placed in the transmission system leading to the shaft in an attempt to reduce the torsional vibrations mentioned above, but damping only by compression coil springs such as torsion springs is insufficient.
Torsional vibration cannot be sufficiently reduced.

Therefore, we arranged a torsion spring mechanism that corresponds to the normal torque range and a torsion spring mechanism that corresponds to the high torque range in a parallel multi-stage system, and also designed to prevent vibrations that occur in the crankshaft etc. in the normal torque range. A clutch mechanism equipped with a coil spring of low spring stiffness that absorbs vibration with good response was proposed.

Here, we can change the spring stiffness by changing the number of springs with the same stiffness, or we can divide springs with different spring stiffness into two sets, one set with high spring stiffness, and the other set with spring stiffness. The torsion spring mechanisms with low rigidity are arranged in parallel, and the torsion spring mechanisms with high spring rigidity are provided with a relief part corresponding to the torsional angle while the torsion spring mechanisms with low spring rigidity are acting. The low part is designed to absorb vibrations in the normal torque range. Therefore, while the transmitted torque increases to a certain value, the first torsion spring mechanism acts, and then when it exceeds a certain value, the relief part disappears and the second torsion spring mechanism works together. Therefore, due to these differences in spring stiffness, the spring stiffness curve showing the relationship between the torsion angle and the torque becomes steep, and a shock due to the discontinuity of the spring stiffness curve occurs during the increase in torque.
This is because the torsion spring mechanisms are arranged in parallel, so there is not enough space for the coil spring, and therefore the torsion rotation angle cannot be large, and the torsion angle is not large relative to the torque. This is because there is a limit to the decrease in spring stiffness.

Therefore, this invention separates the power transmission mechanism into a region with low spring stiffness and a region with high spring stiffness by twisting it, and functionally connects the low region and high region in series to maintain the spring stiffness required for torque transmission. However, it is an object of the present invention to provide a power transmission mechanism for an automobile that can ensure a relatively large twist angle and smoothly increase the transmitted torque.

Hereinafter, the present invention will be specifically explained based on illustrated embodiments. On the end face of the crankshaft 1 of an internal combustion engine for an automobile, there is a second
As shown in the figure, a flywheel 3 is fixed with bolts 2. A clutch cover 4 is fixed to the outer peripheral end surface of the flywheel 3 by means of bolts or the like.
A diaphragm spring 5 is supported by a spring set bolt 6. The diaphragm spring 5 presses the protruding edge of the pressure plate 7 with its outer peripheral edge, and the pressure plate 7 pushes the clutch disk 8 against the flywheel 3.
It presses against the end face of the metal to achieve a clutch connection.

The main drive shaft 9, which is coaxially supported with the crankshaft 1, has a spline shaft portion 10 at its shaft end, and a spline hub 11 is fitted into the spline shaft portion 10. The spline hub 11 is integrally provided with a flange 13 that supports a first torsion spring mechanism 12, and the first torsion spring mechanism 12 has a retaining plate 15 and a transfer plate 1.
6. Consisting of a retainer 12b and a rubber piece 12a,
The flange 13 has a plurality of window holes 1 as shown in FIG.
4 is formed. A rubber piece 1 which is a component of the torsion spring mechanism 12 is provided in the window hole 14.
2a are fitted on both sides via retainers 12b. There are also slits 14a between the window holes 14, and stopper pins 15a provided on the retaining plate 15 and transfer plate 16 provided along one end surface of the flange 13 are located between the slits 14a. There is. Further, a transfer plate 16 is arranged along the opposite end surface of the flange 13, and the transfer plate 16 and the retaining plate 15 have window holes 1 for receiving the torsion spring mechanism 12.
6a and 15b are provided. Further, the boss portion of the transfer plate 16 is provided with dog clutch teeth 17, and the transfer plate 19, which has dog clutch teeth 18 on the end surface of the boss portion that mesh with the dog clutch teeth 17, supports the second torsion spring mechanism 20. There is. Both transfer plates 16 and 19 are rotatably supported by the spline hub 11 via ball bearings 21. As shown in FIG. 1B, which is a sectional view taken along line B in FIG. The transfer plate 19 is composed of a plurality of rubber pieces 20a, which are compressed elastic bodies, arranged in parallel and a retainer 20b arranged between them.
The transfer plate 19 is disposed in an arc-shaped window hole 19c (see FIG. 3, which is a component diagram of the transfer plate 19). In order to prevent the rubber piece 20a from coming off the retainer 20b due to centrifugal force, the retainer 20b has a convex portion with a rivet head, and the rubber piece 20
A is provided with a recess into which it is placed. Furthermore, if necessary, the retainers 20b at both ends are engaged with the jaws of the abutment part 19a formed on the transfer plate 19, and the intermediate retainer 20b is connected to the boss part 20d via the twisted arm part 20c. There is. Another contact portion 19b is formed on the transfer plate 19 in the opposite direction to the contact portion 19a.

Retaining plates 22 and 23 are arranged on both sides of the transfer plate 19.
The clutch disk 8 is fixed by torque stoppers 24 and 25 which also serve as rivets. The above torque stopper 24 and 25
The contact portions 19a and 19b of the transfer plate 19 are opposed to each other in the rotational direction.
A window hole 26 for receiving the torsion spring mechanism 20 is provided.
and 27 are provided on the retaining plates 22 and 23.

When the internal combustion engine is driven and the crankshaft 1 is rotated in the direction of arrow A (counterclockwise) in FIG. 1B, the flywheel 3 is rotated integrally. In a drive state in which the protruding edge of the pressure plate 7 is pressed by the diaphragm spring 5 and the clutch disk 8 is frictionally engaged with the flywheel 3, the retaining plates 22 and 23 are moved as shown in FIG. One of the torque stoppers 25 rotates in a direction in which it comes into contact with the contact portion 19b of the transfer plate 19, and a retainer 20b is disposed on one end side at one edge of the window holes 26 and 27 of the retaining plates 22 and 23. The retainer 20b and the retainer 20b disposed on the other end press the rubber pieces 20a interposed therebetween. When this rubber piece 20a is compressed, the spring force increases, and during normal torque transmission, the compressive deformation of the rubber piece 20a stops at a position where this spring force and the pressing force of the retaining plates 22 and 23 are balanced. The torque fluctuation of the crankshaft 1 is absorbed by compressive deformation of the rubber piece 20a.

Since a plurality of the rubber pieces 20a are arranged along the circumferential direction, which is the torque transmission direction, with the retainer 20b interposed between the opposing surfaces, the rubber pieces 20a
The twist angle can be quite large. Therefore, the rise of the transmitted torque during torque transmission is relatively gradual. Thus, the retaining plates 22 and 23 are rotated relative to the transfer plate 19 to a position corresponding to the torque force until the torque stopper 24 collides with one of the abutting portions 19a. Above transfer plate 1
9 and another transfer plate 16 have a dog clutch structure (dog clutch teeth 17 and 18).
Due to the series arrangement with respect to the transmission system, the first torsion spring mechanism 12 additionally acts on the torque transmission to the main drive shaft 9. That is, the torque applied to the transfer plate 16 is transferred to the rubber piece 12 via the retainer 12b.
a and further flange 13 through its deflection.
Power is transmitted to the stopper pin 15a until the flange 13 comes into contact with the stopper pin 15a. During normal torque transmission, the rubber piece 12a is hardly compressed, but when high torque occurs such as during sudden acceleration, the compression of the rubber piece 20a of the second torsion spring mechanism 20 progresses, causing the torque stop. 2
4 is in a state where it collides with the collision part 19a,
The relative rotation between the retaining plates 22, 23 and the transfer plate 19 stops, and from this point on, the first torsion spring mechanism 12 functions to absorb torque fluctuations of the crankshaft 1 by compression deformation of the rubber piece 12a. There is.

If the torque fluctuation occurs in a portion extending from the second torsion spring mechanism 20 to the first torsion spring mechanism 12, the spring stiffness of the second torsion spring mechanism 20 is made smaller than that of the first torsion spring mechanism 12, and the second torsion spring mechanism Torsion spring mechanism 2
If 0 is selected as a value that takes into account the spring stiffness in the maximum load state and the initial spring stiffness of the first torsion spring mechanism 12, the spring stiffness curve obtained by both torsion spring mechanisms 12 and 20 will be at the node. They are not smooth and can also be placed in series with each other and
Since each of them has a sufficient twist angle, the effect that the transmission torque rises relatively slowly can be obtained.

Furthermore, during engine braking, that is, when power is transmitted from the main drive shaft 9 to the crankshaft 1, the power is transmitted along a path opposite to that in the drive state. That is, the torque applied to the flange 13 is applied to the first torsion spring mechanism 1.
2 to the retaining plate 15 and the transfer plate 16, from the transfer plate 16 via the dog clutch mechanism to the transfer plate 19, and further via the second torsion spring mechanism 20 to the retaining plate 15 and the transfer plate 16. 22 and 23. As the torque gradually decreases, the torsion angles of the first torsion spring mechanism 12 and the second torsion spring mechanism 20 decrease in this order, so that torque is transmitted along a smooth spring stiffness curve in this case as well.

In this embodiment, transfer plates 16 and 19 are used as intermediate drive members that support each torsion spring mechanism 12 and 20, and these are rotatably supported by spline hub 11 via ball bearings 21. This makes it easy to center each transfer plate and minimize rotational vibration.

Furthermore, in this embodiment, the torque stoppers 24 and 25 also function as rivets for fixing the clutch disk 8 to the retaining plates 22 and 23, so the number of parts can be reduced and the structure can be simplified.

As described in detail above, the present invention provides a torsional system for transmitting torque from the crankshaft of an internal combustion engine to the main drive shaft of a transmission via a clutch disk. A plurality of torsion spring mechanisms that act elastically in the direction are functionally interposed in series between the clutch disk and the main drive shaft along the rotational axis direction of the main drive shaft, and the plurality of torsion springs At least one of the mechanisms is a torsion spring mechanism in which a plurality of compressed elastic bodies with retainers interposed between opposing surfaces are arranged along the circumferential direction, which is the torque transmission direction, so a relatively large torsion angle is achieved. It is possible to bring about a gradual change in the rise of torque, and the spring stiffness can be made relatively small. Further, by arranging the torsion spring mechanisms in series with each other in the transmission system, there is an effect that a more sufficient torsion angle can be obtained.

[Brief explanation of drawings]

FIG. 1A is a sectional view taken along line A in FIG. 2 (between the retaining plate and flange located on the crankshaft side) and shows the first torsion spring mechanism; FIG. , is a cross-sectional view along line B (between the retaining plate and the transfer plate located on the crankshaft side) of FIG. 2, showing the second torsion spring mechanism. FIG. 3 is a front view and a sectional view showing the transfer plate, and FIG. 4 is an explanatory view showing the operating state of the second torsion spring mechanism. . 1... Clamp shaft, 8... Clutch desk, 9... Main drive shaft, 15... Retaining plate, 16... Transfer plate, 17, 18... Dog clutch tooth, 12,
20...Torsion spring mechanism, 12a, 20a...Rubber piece, 12b, 20b...Retainer, 19...Transfer plate, 22, 23...Retaining plate, 24, 25, 15a...Stopper pin.

Claims (1)

[Scope of Claims] 1. In a device that transmits torque from a crankshaft of an internal combustion machine to a main drive shaft of a transmission via a clutch disk, a plurality of torsion spring mechanisms that act elastically in the torsional direction are connected to the clutch disk and the above-mentioned clutch disk. The torsion spring mechanism is functionally interposed in series with the main drive shaft along the rotational axis direction of the main drive shaft, and at least one of the plurality of torsion spring mechanisms has a retainer interposed between opposing surfaces. A power transmission mechanism for an automobile, characterized in that it is a torsion spring mechanism in which a plurality of compression type elastic bodies are arranged along a circumferential direction, which is a torque transmission direction. 2. The power transmission mechanism for an automobile according to claim 1, wherein the compressible elastic body is made of rubber. 3 In what is stated in claim 1,
A power transmission mechanism for an automobile, wherein a torque stopper that restricts the relative rotation of a transfer plate supporting the torsion spring mechanism having a compression type elastic body with respect to the retaining plate is also used as a rivet for attaching a clutch disk to the retaining plate. . 4 In what is stated in claim 1,
A power transmission mechanism for an automobile, characterized in that transfer plates, which are intermediate drive members that support each torsion spring mechanism, are connected to each other by a dog clutch and supported on a spline hub via bearings.