JP4731430B2 - Torsional damper and manufacturing method thereof - Google Patents

Description

  The present invention relates to a torsional damper that is attached to a propulsion shaft (propeller shaft) of an automobile, for example, to reduce its torsional vibration.

Conventionally, it is known to attach a torsional damper for reducing torsional vibration to an automobile propulsion shaft or an engine output shaft. For example, in Patent Documents 1 and 2, a steel plate damper plate is attached so as to rotate integrally with the crankshaft end of the engine, and annular weights (inertia) are attached to both side surfaces of the damper plate via rubber elastic bodies, respectively. A double-mass type with a body attached is described.
Utility Model Registration No. 2604944 Utility Model Registration No. 2607474

  By the way, the propulsion shaft (propeller shaft) of an automobile is normally arranged so as to extend in the front-rear direction below the floor of the vehicle body. On paved roads, there are many cases of interference with road surface protrusions, falling rocks, etc., which may cause damage.

  That is, in the torsional damper in which the damper plate and the weight are arranged in the front-rear direction as in the conventional example, the damper plate protrudes relatively outward in the radial direction. When it interferes with, it is easy to receive the impact of the front-back direction, and this causes permanent set (plastic deformation).

  If permanent deformation occurs in the damper plate due to the impact in the front-rear direction, excessive tensile strain will occur in the rubber elastic body with the subsequent rotation of the propulsion shaft, which makes the rubber elastic body extremely durable. It is thought that it will be damaged and lead to breakage.

  The present invention has been made in view of such a point, and the object of the present invention is to devise the shape of the weight attached to the front surface of the damper plate and impact due to interference with the convex portion of the road surface. Therefore, it is difficult to act on the damper plate to suppress a decrease in durability caused by the permanent distortion.

  In order to achieve the above object, in the present invention, at least the outer peripheral side of the vehicle front side surface of the weight is formed in a convex curved surface, and the weight is displaced obliquely upward when impacted there, It is designed to give a shock.

  Specifically, according to the first aspect of the present invention, a damper plate is attached so as to rotate integrally with a rotating shaft extending in the front-rear direction of the vehicle, and an annular shape is provided on the front surface of the damper plate via a rubber elastic body. For the torsional damper to which the weight is attached, the surface of the weight on the front side of the vehicle is inclined so that the outer peripheral side is located at the rear side of the vehicle at least in the range of the outer peripheral side, and the inclination is The outer circumferential edge of the weight is positioned more radially outward than the radially outer end of the damper plate.

  In the torsional damper having the above-described configuration, the damper plate rotates integrally with the rotation of the rotating shaft, and the weight also rotates through the rubber elastic body as the damper plate rotates. When the rotation speed of the rotation shaft and the damper plate changes, the weight becomes an inertial mass and the rubber elastic body is distorted to absorb the change in the rotation speed, so that the rotation fluctuation in a specific frequency band, that is, the torsional vibration of the rotation shaft Can be effectively reduced.

  Here, when the rotating shaft is a propulsion shaft disposed under the floor of an automobile, an impact in the front-rear direction may act on the weight due to interference with a convex portion of the road surface during traveling. The front side surface of the vehicle is inclined so that the outer peripheral side is located at the rear side of the vehicle at least in the outer peripheral side range, and the convex side is formed so that the inclination becomes stronger toward the rear side of the vehicle. When an impact in the front-rear direction acts on the weight, the entire weight or torsional damper is displaced obliquely upward, so that the impact is applied, and the impact is unlikely to act on the damper plate.

  Therefore, it becomes difficult for permanent deformation to occur in the damper plate even by interference with the convex portion of the road surface, and it is possible to suppress a decrease in durability of the rubber elastic body due to this permanent distortion. In addition, since the outer peripheral edge of the weight is positioned radially outward from the radial outer end of the damper plate, there is no fear that the impact in the front-rear direction acts directly on the damper plate.

  Preferably, the weight is a press-molded product made of a metal plate, and in this way, a three-dimensionally curved weight can be obtained at a relatively low cost. (Invention of Claim 2).

  Such a configuration is particularly useful in a so-called double mass type torsional damper in which two weights are attached to a damper plate. In other words, if there is only one weight, it may be arranged around the outer periphery of the damper plate, and the two may be connected in the radial direction by a rubber elastic body. In such a case, the weight interferes with the convex part of the road surface. This is because the impact in the front-rear direction does not act on the damper plate.

  Specifically, the damper plate is joined to the end surface of the rotating shaft, a cylindrical portion that is bent from the outer peripheral edge and extends in the direction of the rotating shaft, and is bent from the tip to radially outward. It is preferable that a weight is disposed on the front surface of the flange portion on the vehicle front side, and another annular weight is attached to the outer peripheral surface of the cylindrical portion via a rubber elastic body. (Invention of Claim 3).

  By attaching two weights to the damper plate in this way, the frequency band of torsional vibration that can be effectively reduced is widened. Further, since another weight disposed on the outer periphery of the cylindrical portion of the damper plate is located behind the flange portion, it is possible to easily prevent an impact from acting directly on the other weight. it can.

  A preferable method for manufacturing the torsional damper as described above is to first form a rubber elastic body and an annular metal flat plate on one surface of the damper plate by vulcanization, and then at least in the flat plate member. The outer peripheral side range is press-molded so that the outer peripheral side is inclined so as to be located on the other side of the damper plate, and is curved so that the inclination becomes stronger toward the other side. Invention).

  That is, first, a rubber plate and a metal flat plate are vulcanized and integrally formed on the damper plate, so that a flat plate serving as a weight can be attached relatively easily. In this case, if the plate material has a curved shape, there is a risk that it will be very difficult to split the rubber mold, but such a problem does not occur if it is a flat plate material. Thus, the torsional damper having the above-described configuration can be obtained by pressing and bending the flat plate material in a state of being attached to the damper plate.

  As described above, the torsional damper according to the present invention forms a convex curved surface on at least the outer peripheral side of the vehicle front side surface of the weight so as to perform the impact in the front-rear direction due to the interference with the convex portion of the road surface. As a result, it is difficult for permanent deformation to occur in the damper plate, and a decrease in durability due to this can be suppressed.

  Further, when manufacturing the torsional damper as described above, first, after the rubber elastic body and the flat plate material are integrally vulcanized and formed on the damper plate, the flat plate material is press-molded and curved, as described above. Even if the outer peripheral side of the weight is curved into a convex curved surface, it is not difficult to split the mold of the rubber elastic body.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  FIG. 1 shows an embodiment of a torsional damper A according to the present invention, which includes, for example, a rear end of a propulsion shaft P and a final reduction gear D in a power transmission system of an automobile as schematically shown in FIG. And is used to reduce torsional vibration. In the illustrated power transmission system, a propulsion shaft P extends from the engine E and the transmission T arranged vertically in the front of the vehicle body toward the rear of the vehicle body (hereinafter, the front-rear direction of the vehicle body is simply referred to as the front-rear direction). The rear wheel axle S is connected to the rear end thereof via a final reduction gear D. The rear wheel axle S extends in the vehicle width direction and is connected to a vehicle body (not shown) via a leaf spring L so as to be movable up and down.

  As shown in part in a cross-sectional view in FIG. 1 (b), the torsional damper A of this embodiment includes a damper plate 1 in which a steel plate is deep-drawn and formed into a hat shape, and rubber layers 2 and 3 respectively. It is of the double mass type provided with two annular weights 4 and 5 attached via each other. Specifically, as shown in FIG. 3, the damper plate 1 includes a rectangular plate-like joint 10 that is joined to a flange 60 (the rear end face of the shaft) of the hook-type joint 6 located at the rear end of the propulsion shaft P, and A cylindrical section 11 having a rectangular cross section that is bent forward from the entire outer periphery of the joint section 10, and a flange section 12 that is bent from the front end of the joint section 10 in a radially outward direction and has a circular outer periphery. .

  The joint portion 10 of the damper plate 1 is overlapped with the flange 60 of the hook joint 6 from the rear, and the flange 70 at the front end of the input shaft 7 of the final reduction gear D is overlapped from the rear to be sandwiched between the front and rear. It is. A round hole 13 is formed at the center of the joint 10 so that the protrusion at the front end of the input shaft 7 is fitted therein, and a plurality of through holes 14, 14,... Are fastened together with the front and rear flanges 60, 70 by means of 8, 8,... And nuts 9, 9,.

  A rubber layer 2 is formed on the outer peripheral surface of the cylindrical portion 11 of the damper plate 1, and a cylindrical first weight 4 is attached so as to surround the entire outer periphery. The first weight 4 can be obtained by deep drawing of a thin steel plate or cutting a steel pipe, but may be a casting. On the other hand, an annular rubber layer 3 is formed on the front side surface of the flange portion 12 of the damper plate 1. ing. Note that flange-shaped through holes 15, 15,...

  The feature of the present invention lies in the shape of the second weight 5, and the front side surface of the second weight 5 is in the range of about 2/3 of the radial dimension from the outer peripheral edge toward the inner peripheral side, that is, rubber. The range excluding the inner peripheral part attached to the flange portion 12 of the damper plate 1 via the layer 3 is inclined so that the outer peripheral side is located on the rear side, and the inclination is toward the rear side. It is formed in a convex curved surface that becomes stronger. And the outer periphery of the 2nd weight 5 is located so that the whole flange part 12 of the damper plate 1 may be enclosed from radial direction outer side.

  In this embodiment, the second weight 5 is made of a steel plate (may be another metal plate material), is vulcanized and integrally formed with the rubber layer 3 in a flat plate state, and is attached to the flange portion 12 of the damper plate 1. Later, it is press-molded to obtain a curved shape as described above. By using a press-molded product in this way, the second weight 5 having a three-dimensionally curved shape can be obtained relatively inexpensively.

  Specifically, at the time of manufacturing the torsional damper A, first, the damper plate 1 and the first weight 4 and the annular flat plate material 5 ′ to be the second weight 5 are respectively set in a rubber mold, A predetermined amount of the unvulcanized rubber composition that becomes the rubber layers 2 and 3 is also set, and these are heated and pressurized to be integrally vulcanized. Thus, at the time of vulcanization integral molding, the second weight 5 is not curved, but is a flat plate material 5 ', so that it is not difficult to split the mold. The damper plate 1, the first weight 4 and the flat plate material 5 'are preliminarily coated with an adhesive at the site where the rubber is applied.

  Then, the first weight 4 is attached to the outer peripheral surface of the intermediate product as shown in FIG. 4, that is, the cylindrical portion 11 of the damper plate 1 via the rubber layer 2, and on one surface of the flange portion 12. If the thing to which flat plate material 5 'was attached via the rubber layer 3 is obtained, this will be attached to a press molding machine. Then, as schematically shown by a black arrow in FIG. 5B, the flat plate 5 ′ is pressed by the movable die while holding the flange portion 12 of the damper plate 1 from the other side by the fixed die (white). It is tilted so that it is located on the other side toward the outer peripheral side, and curved so that the tilt becomes stronger toward the other side.

  When the torsional damper A manufactured as described above is attached to the propulsion shaft P of the automobile, the damper plate 1 rotates integrally with the propulsion shaft P during the traveling of the automobile, Thus, the first and second weights 4 and 5 also rotate through the rubber layers 2 and 3. At this time, the rotational fluctuation (torsional vibration) of the propulsion shaft P is absorbed by the first and second weights 4 and 5 becoming inertia masses and the rubber layers 2 and 3 being distorted. Thus, the first and second weights 4 and 5 are attached and each function as a dynamic damper, so that the frequency band of torsional vibration that can be effectively reduced is widened.

  Further, during traveling of the automobile, the second weight 5 located at the foremost portion of the torsional damper A attached to the rear end of the propulsion shaft P as described above may interfere with the convex portion of the road surface. Then, as schematically shown by the black arrow in FIG. 5, the impact F in the front-rear direction acts on the second weight 5, and thus the portion where the impact F acts (the outer peripheral side 2/3 of the vehicle front side surface). 2) is formed in a convex curved surface shape, the second weight 5 or the entire torsional damper A that has received the impact F is displaced rearward and obliquely upward as shown by the white arrow in the figure. .

  That is, the impact F in the front-rear direction due to the interference with the convex portion of the road surface is applied to the surface of the second weight 5 formed in the convex curved surface shape, and acts on the flange portion 12 of the damper plate 1. hard. For this reason, it is difficult for permanent deformation to occur in the flange portion 12 of the damper plate 1 even when traveling on rough roads, and it is possible to suppress the occurrence of excessive tensile distortion in the rubber layer 3 due to this permanent distortion. Therefore, a decrease in durability of the torsional damper A can be suppressed.

  Since the outer peripheral edge of the second weight 5 is located radially outward from the outer peripheral edge of the flange portion 12 of the damper plate 1, there is a concern that the front and rear impacts may act directly on the flange portion 12. Absent. Further, since the first weight 4 is located behind the flange portion 12 and radially inward from the flange portion 12, there is no possibility that an impact is directly applied thereto.

  As described above, the second weight 5 need not be a press-formed product of a steel plate, and may be a casting. In this way, as shown in FIG. 6, the entire second weight 5 can be curved as well as the outer periphery of the second weight 5, but the second weight 5 having such a curved shape is set in the mold. Since the rubber layers 2 and 3 are formed, it is difficult to split the mold.

  The torsional damper according to the present invention can be applied not only to the double mass type as in the above embodiment, but also to the torsional damper having only one weight.

  Furthermore, the torsional damper according to the present invention is not limited to the one attached to the propulsion shaft P of the automobile as in the above embodiment, and for example, there is a possibility that an impact from the front of the vehicle acts on the output shaft of the engine or motor. It is also applicable to cases.

  As described above, the torsional damper according to the present invention has a simple configuration in which the front surface of the weight located on the front side of the vehicle is formed in a convex curved surface shape, and durability resulting from interference with a convex portion of the road surface, etc. This is particularly suitable for use in a vehicle propulsion shaft.

It is a perspective view which shows the torsional damper which concerns on this invention, (a) shows the whole, (b) shows a part as a cross section. It is a schematic block diagram of the power transmission system of the motor vehicle using the damper. It is an expanded sectional view showing the attachment structure to the propulsion shaft end of the damper. FIG. 2 is a view corresponding to FIG. 1 showing a state of the intermediate product after vulcanization integral molding of the damper. It is explanatory drawing which shows typically a mode that the impact of the front-back direction by interference with the convex part etc. of a road surface is made. It is a figure equivalent to Drawing 1 (b) concerning a modification which formed a weight by casting.

Explanation of symbols

A Torsional damper P Propeller shaft (rotary shaft)
DESCRIPTION OF SYMBOLS 1 Damper plate 10 Joint part 11 Cylindrical part 12 Flange part 2, 3 Rubber layer (rubber elastic body)
4 First weight (another weight)
5 Second weight (weight)
5 'Metal flat plate

Claims (4)

This is a torsional damper in which a damper plate is attached so as to rotate integrally with a rotating shaft extending in the longitudinal direction of the vehicle, and an annular weight is attached to the front surface of the damper plate via a rubber elastic body. And
The front surface of the weight is inclined so that the outer peripheral side is located at the rear side of the vehicle at least in the outer peripheral range, and the inclined surface is formed in a convex curved surface shape that becomes stronger toward the rear side of the vehicle, and A torsional damper, wherein an outer peripheral edge of the weight is located radially outward from a radially outer end of the damper plate.   2. The torsional damper according to claim 1, wherein the weight is a press-formed product of a metal plate material. The damper plate includes a joining portion joined to the end surface of the rotating shaft, a cylindrical portion that is bent from the outer peripheral edge and extends in the direction of the rotating shaft, and a flange portion that is bent from the tip and extends radially outward. Prepared,
A weight is disposed on the front surface of the flange portion of the vehicle,
3. The torsional damper according to claim 1, wherein another annular weight is attached to the outer peripheral surface of the cylindrical portion via a rubber elastic body. A method for manufacturing a torsional damper according to any one of claims 2 and 3,
A rubber elastic body and an annular metal flat plate are integrally vulcanized on one surface of the damper plate,
Thereafter, at least the outer peripheral side range of the flat plate material is press-molded, and is inclined so that the outer peripheral side is positioned on the other side of the damper plate, and the inclination is curved so as to become stronger toward the other side. A method of manufacturing a torsional damper.

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