JPS5973643A - Internal combustion engine camshaft vibration suppression device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a method for damping vibrations caused by torsion of a camshaft in a valve mechanism of an internal combustion engine by attaching a torsional damper device comprising a weight unit to an end portion of the camshaft. The present invention relates to a camshaft vibration suppression device for an internal combustion engine.

Caused by torsion of the camshaft in the valve mechanism of an internal combustion engine
This section explains the vibrations that occur. In FIG. 8, internal combustion engine 1
The valve mechanism 00 opens and closes the pulp 105, which is disposed in the opening 104 of the cylinder head 101 so as to completely communicate with and block the combustion chamber 102 and the intake hole (or exhaust hole) 103. The mechanism is a support shaft 108Q) due to the periodic contact relationship between a camshaft 106 connected to a crankshaft (not shown) via a rotary motion transmission mechanism, and a cam 107 formed on the camshaft 106. Repeat the saw movement 9iy-times to remove the rear end 1 of the pulp 105 against the pulp spring 110 at the right end 109a in the figure.
05a″f: Consists of a rocker arm 109 that periodically pushes down the pulp 105 to open and close it.

In addition, the pulp 109 has its rod-shaped stem connected to the pulp guide 1.
11, and a spring receiver 105b' is installed at the rear thereof.
The valve mechanism is provided in a cylinder head cover 112 that is fixedly mounted on the cylinder head 101, and is elastically supported by a pulp spring 110 that contacts the valve mechanism.

In the above, as shown in FIG.
When the cam 107 rotates and the cam 107 tries to push up the left end of the rocker arm 109 in FIG. On the other hand, the rotational force of the gear 116 of the crankshaft 115 acts on the camshaft gear 113 fixed to the camshaft 106 through a chain 114 or the like, and as a result, the cam 107 and the camshaft gear 113 A difference in rotation occurs between the two, causing twisting in the camshaft between the two. After the cam 107 pushes up the rocker arm 109, a restoring force is generated based on the above-mentioned torsion. In this way, each time the cam 107 acts on the rocker arm 109, twisting and restoration are repeated between the cam 107 and the camshaft gear 113, and the camshaft 106
Vibrations caused by the torsion are generated, and when these vibrations match the natural vibration of the camshaft itself in terms of frequency, resonance occurs and the vibrations caused by the torsion become even larger.

When the above-mentioned torsional vibration occurs, tensile force is repeatedly applied to the chain 114, etc., which is a driving force transmission member between the camshaft gear and the crankshaft gear, which causes an abnormal load on the chain 114 etc. It's not a bad thing. Therefore, in order to remove the above-mentioned abnormal load, it is necessary to take measures to prevent the occurrence of torsional vibration in the camshaft 106.

The present inventor has devised the present invention in order to effectively solve the above problem, and in principle, the resonance point of the camshaft is at a rotation speed of 300 orpm in a 4-cycle internal combustion engine.
Based on the experimental knowledge that when the number of cylinders is 4, the vibration is a low frequency of about 100 Hz, the camshaft is provided with a torsional damper device that absorbs the vibration of about 100 Hz.

An object of the present invention is to attach a weight unit, which includes an annular weight disposed around the outer periphery of an annular member via an elastic connecting body, to an end of a camshaft of an internal combustion engine. It absorbs the torsional vibrations generated in the camshaft, thereby preventing the occurrence of abnormal loads on drive force transmission members such as chains and belts, extending their lifespan, and simplifying their assembly. The purpose is to provide full camshaft vibration suppression for internal combustion engines.

Another object of the present invention is to provide the camshaft vibration suppressing device, in which the elastic coupling body is divided into a plurality of parts in the radial direction and formed into continuous layers in the circumferential direction, and a rigid plate is interposed between them. Alternatively, camshaft vibration suppression for an internal combustion engine is provided in which a member is provided to completely restrict deformation in the elastic coupling body, thereby regulating the shape change of the elastic coupling body and effectively reducing torsional vibration generated in the camshaft. The goal is to provide equipment.

A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

In FIGS. 1 and 2, a plurality of cams are driven by a crankshaft gear (or crankshaft pulley, etc.), which is a driving rotary body fixed to a crankshaft (not shown), on the small diameter portion 2a at one end of the camshaft 2. Rotational motion can be transmitted through a chain (or belt, etc.) 3 that is a force transmitting member. A camshaft gear (or camshaft pulley, etc.) 4, which is a driven rotating body, is fixed. The camshaft 2 is used to periodically swing the corresponding rocker arms as described above based on its rotational motion, thereby operating the valve mechanism that controls intake and exhaust air in an internal combustion engine. .

A torsional damper device 6 is fixed to the left end of the camshaft 20 in the drawing by a port 5.

The torsional damper device 6 consists of a weight body unit, and specifically, an inner ring member 7 having a U-shaped cross section and having a hole 7a' that fits into the small diameter portion 2a of the camshaft 2;
1. An annular elastic connecting body 8 made of rubber or the like is attached to the outer periphery of the inner ring member 7, and an annular weight body 9 is integrated with the annular elastic connecting body 8 made of rubber or the like. By fitting the hole 78 into the small diameter portion 2a of the camshaft 2, inserting the washer 10 into the threaded hole 2b of the camshaft 2, and screwing the port 5, the torsional damper device 6 is attached to the camshaft 2. Tie it to the middle left end.

According to the above configuration, the aforementioned low-frequency torsional vibration generated in the camshaft 2 during rotation can be absorbed by the elastic coupling body 8 and the annular weight body 9 and can be reduced. The hardness of the elastic coupling body 8 is appropriately selected depending on the frequency of torsional vibration.

FIG. 3 shows a modified embodiment in which the elastic connectors are all formed into spoke shapes. In this figure, for example, three elastic connectors 11 are arranged at equal intervals between the inner ring member 7 and the annular weight body 9.・・・
・There is an intervention. According to this, the weight can be reduced by completely reducing the amount of elastic bodies. In addition, in view of the fact that the deformation of the elastic coupling bodies 11 in the circumferential direction and radial direction increases when the camshaft rotates due to the reduction in the amount of elastic bodies, an annular weight is inserted between the elastic coupling bodies 11... A substantially trapezoidal deformation regulating member 12 made of rubber or the like, for example, can be provided fixedly attached to the inner surface of the member 9 . This makes it possible to suppress vibrations caused by vibration input in the eccentric direction, such as secondary vibrations of an in-line four-cylinder engine.

Figures 4 and 5 show an embodiment in which the above-mentioned elastic connector is provided with a reinforcing plate, and in explaining this embodiment, the same elements in the above embodiment will be denoted by the same reference numerals in the drawings. do. In Figures 4 and 5, the camshaft 2
A torsional damper device 6 is fixedly installed at the left end in FIG. An annular elastic body 14°1 continuous in the circumferential direction
5.16, and an annular rigid plate 17.18 made of a steel plate, an aluminum plate, etc., interposed between them, elastic bodies 14, 15 made of, for example, rubber etc. 16, and a rigid plate 17,
18, the inner ring member 7 and the annular weight body 9 are integrally bonded to each other with the same degree of baking.

In the above configuration, the elastic connectors 13 are formed continuously in the circumferential direction in an annular shape, but as shown in FIG. 6, for example, three elastic connectors 19 may be provided in a spoke shape. It is possible. In this case as well, the elastic connector 19
... consists of three layered elastic bodies 20, 21, 22 and rigid plates 23, 24 interposed between them. In addition, as shown in the figure (the eccentric displacement of the annular weight body 9 due to the deformation of the elastic coupling bodies 19... should be completely restricted) (as in FIG. 3, the deformation regulating members 25...・It is placed between.

According to the above configuration, for example, the spoke-shaped elastic connector 11
As shown in FIGS. 7A and 7B, which compare the elastic connector 19 and the elastic connector 19, the elastic connector 19 is better in the compression direction than the elastic connector 11 because of the rigid plates 23 and 24. When force is applied, the circumferential bulge of the elastic body becomes smaller,
The degree of deformation as an elastic connector is reduced. In the annular weight body 9, when the torsional elastic constant in the rotational direction of the elastic connecting body 11 is set low in order to set the resonance frequency in the rotational direction to be full, the elastic constant in the eccentric direction also becomes low.
Vibration increases due to the imbalance, but the elastic constant in the eccentric direction can be set high by the action of the rigid plate, thereby making it possible to further suppress the vibration.

According to the present invention, the following effects are achieved.

First, it completely absorbs and reduces the low-frequency torsional vibrations generated in the camshaft, thereby preventing abnormal loads from being applied to the drive force transmission member and extending the life of the drive force transmission member. . Eccentric displacement in the radial direction of the annular weight body can be prevented by attaching the entire regulating member or by providing a rigid plate in the elastic connecting body, thereby absorbing and suppressing torsional vibration even more effectively. can. In particular, the torsional damper device can be easily fixed to the end of the camshaft with bolts or the like as a unit, and its assembly is extremely easy.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, and FIG. 1 is a longitudinal cross-sectional view of a torsion damper installed at the end of the camshaft;
2 is a rotational view in direction A in FIG. 1, FIG. 3 is a front view showing a modified embodiment of the torsional damper device, FIG. 4 is a view similar to FIG. 1 according to another invention, and FIG. The figure is a rotational view in the B direction in Fig. 4, Fig. 6 is a front view showing a modified embodiment of a torsional damper device according to another invention, and Figs. 7 (A) and (B) are deformations of the elastic coupling body. FIG. 8 is a partial longitudinal sectional view of the internal combustion engine showing the entire valve mechanism, and FIG. 9 is a diagram for explaining the occurrence of torsional vibration. In the drawings, 1 is a cam, 2 is a camshaft, 3 is a chain, 4 is a camshaft gear, 6 is a torsional damper device consisting of a weight unit, 7 is an inner ring member, 8, 11, 1
3.19 is an elastic coupling body, 9 is an annular weight body, 12.25 is a deformation regulating member, and 17° 18.23.24 is a rigid plate. Patent Applicant Honda Motor Co., Ltd. Agent Patent Attorney 2 1) Part 1 Patent Attorney Kuni Ohashi Intention Patent Attorney 2
Yama Yu Figure 8 Figure 9 269-

Claims (7)

[Claims] (1) In an internal combustion engine in which a driving rotary body fixed to a crankshaft and a driven rotary body fixed to a camshaft are connected by a driving force transmission member, and the rotational motion of the crankshaft is transmitted to the camshaft, the above-mentioned cam A camshaft vibration suppressing device for an internal combustion engine, characterized in that a weight body unit comprising an annular weight entirely disposed by an elastic connecting body around the outer periphery of an annular member is attached to an end of the shaft. (2) The camshaft vibration suppressing device for an internal combustion engine as set forth in Patent No. 1, wherein the elastic connecting body is annular and is provided so as to be filled between the annular member and the annular weight. (3) A camshaft for an internal combustion engine according to claim 1, wherein the elastic coupling body is formed into a spoke shape and is provided at a plurality of locations between the annular member and the annular weight body. Vibration suppressor. (4) In an internal combustion engine in which a driving rotary body fixed to a crankshaft and a driven rotary body fixed to a camshaft are connected by a driving force transmission member, and the rotational motion of the crankshaft is transmitted to the camshaft, the cam A weight body unit is attached to the end of the shaft, which is made up of an annular weight with an elastic connecting body around the outer periphery of an annular member, and the elastic connecting body is formed of a plurality of continuous layers in the circumferential direction. A camshaft vibration suppression device for an internal combustion engine, characterized in that a rigid plate is interposed between each layer. (5) The camshaft vibration suppressing device for an internal combustion engine as set forth in claim 4, characterized in that the elastic coupling body and the rigid plate are formed in the shape of IJ. (6) A camshaft for an internal combustion engine according to claim 4, characterized in that the connecting portion between the annular member and the annular weight, which is composed of the elastic connecting body and the rigid plate, is entirely formed in a spoke shape. Vibration suppressor. (7) In an internal combustion engine in which a driving rotary body fixed to a crankshaft and a driven rotary body fixed to a camshaft are connected by a full driving force transmission member, and the rotational motion of the crankshaft is transmitted to the camshaft, the cam A weight body unit is attached to the end of the shaft, and the annular weight body is arranged around the outer periphery of an annular member via a plurality of spoke-shaped elastic connecting bodies. A camshaft vibration suppression device for an internal combustion engine, characterized in that a deformation regulating member is disposed fixed to the inner surface of a weight body.