JP2010144909A - Dynamic damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dynamic damper capable of surely absorbing vibration. <P>SOLUTION: The dynamic damper includes: a cylindrical body having a first opening at one end and a second opening at the other end; a rod-like shaft body inserted in the cylindrical body; and bridges made of elastic bodies with one side joined to the inside surface of the cylindrical body and with the other side joined to the outside surface of the shaft body to connect the cylindrical body to the shaft body, wherein one of the cylindrical body and the shaft body is formed as a weight. The dynamic damper includes first bridges disposed on the first opening side rather than an intermediate position between the first opening and second opening, and second bridges disposed on the second opening side. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a dynamic damper.

  Conventionally, in order to suppress vibration generated in a propeller shaft of an automobile, a dynamic damper is mounted in the hollow propeller shaft.

  The dynamic damper has a cylindrical cylindrical body that can be inserted into a cylindrical propeller shaft, a shaft body that is coaxially disposed in the cylindrical body, one of which is joined to the inner side surface of the cylindrical body, and the other. It is composed of a plurality of rubber bridges that join the outer surface of the shaft body to connect the cylinder and the shaft body.

  In this case, the shaft body is a weight having a predetermined weight, and the dynamic damper can absorb vibrations of a predetermined frequency by adjusting the size and shape of the bridge (see, for example, Patent Document 1 and Patent Document 2). ).

  Such a dynamic damper is a bridge formed by inserting a shaft into a cylinder, fixing the cylinder and the shaft with a mold for injection molding, and injecting rubber between the cylinder and the shaft. Is forming. In particular, the bridge can be molded into a desired size or shape by an injection mold.

Usually, a plurality of bridges are provided at equal angles in the circumferential direction of the shaft body, and are provided at an intermediate position between the first opening at one end of the cylindrical tube and the second opening at the other end.
Japanese Patent Laid-Open No. 08-290722 JP 09-053686 A

  However, in the dynamic damper, for example, as shown in a side view in FIG. 7A and in a vertical end view in FIG. 7B, a cylindrical weight is inserted into a cylindrical cylinder 100 via a plurality of bridges 210. If the thickness of the bridge 210 provided in the circumferential direction of the weight 300 is not sufficient, as shown in FIG. 8, the bridge 210 buckles due to the weight of the weight 300 and is absorbed. There was a risk that it would not be possible to absorb the vibration of the.

  Alternatively, for example, as shown in a side view in FIG. 9A and in a vertical end view in FIG. 9B, a cylindrical weight 300 is provided in a cylindrical tubular body 100 via a plurality of bridges 220. If the length of the bridge 220 in the longitudinal direction of the weight 300 is not sufficient, the weight 300 may be inclined with respect to the cylinder 100 as shown in FIG. When absorbing weight, abnormal vibration such as pitching is likely to occur in the weight 300, and there is a possibility that the vibration to be absorbed cannot be absorbed.

  Therefore, when forming the bridge 200, it is necessary to make the weight 300 larger than the desired thickness or length so that the weight 300 can be vibrated properly, and the design freedom of the bridge 200 is limited. Therefore, the weight 300 must be adjustable, and the shape of the weight 300 is likely to be diversified, which hinders cost reduction.

  In view of such a current situation, the present inventors provide a bridge structure with improved weight support, thereby increasing the degree of design freedom of the bridge and sharing the weight, enabling cost reduction, The present invention has been accomplished through research and development to provide a dynamic damper capable of reliably absorbing vibration.

  A dynamic damper according to the present invention has a cylindrical body having a first opening at one end and a second opening at the other end, a rod-shaped shaft inserted into the cylindrical body, and one side joined to the inner surface of the cylindrical body. In a dynamic damper having an elastic bridge that joins the other side to the outer surface of the shaft body to connect the cylinder body and the shaft body, and having either the cylinder body or the shaft body as a weight, The first bridge disposed on the first opening side with respect to the middle position of the second opening and the second bridge disposed on the second opening side are provided.

  Further, in the dynamic damper of the present invention, a plurality of first bridges and second bridges are arranged at a predetermined pitch in the circumferential direction of the shaft body, and the first bridge is disposed in the circumferential direction of the shaft body with respect to the second bridge. The number of the first bridges and the number of the second bridges are n, and the first bridge is projected in the axial direction of the shaft body with the second elastic piece. It is also characterized by being disposed at a position forming an angle of 360 / n / 2 degrees.

  In the dynamic damper of the present invention, a cylinder having a first opening at one end and a second opening at the other end, a rod-shaped shaft inserted into the cylinder, and one of the cylinders abutting against the inner surface of the cylinder And an elastic bridge that connects the cylindrical body and the shaft body by bringing the other into contact with the outer surface of the shaft body, and a dynamic damper using either the cylindrical body or the shaft body as a weight. By providing a first bridge disposed on the first opening side with respect to the intermediate position between the opening and the second opening and a second bridge disposed on the second opening side, the shaft body is arranged on the center line of the cylindrical body. It is easy to install, and it is possible to prevent the shaft body from pitching due to vibration, and the thickness of the first bridge and the second bridge can be increased, so that the first bridge and the second bridge are buckled. Desired vibration It can provide a dynamic damper having the possibility and the vibration absorbing property absorbed.

  The dynamic damper of the present invention has a first opening 11 at one end and a second end as shown in a side view in FIG. 1 (a), a vertical end view in FIG. 1 (b), and a perspective view in FIG. The cylindrical body 10 having the second opening 12 at the end, the rod-shaped shaft body 30 inserted into the cylindrical body 10, one of them is joined to the inner surface of the tubular body 10 and the other is joined to the outer surface of the shaft body 30. The plurality of elastic bridges 20 connecting the cylindrical body 10 and the shaft body 30 are configured. In this embodiment, the shaft body 30 has a weight of a predetermined weight.

  In particular, the bridge 20 has a first bridge 21 disposed closer to the first opening 11 than an intermediate position K between the first opening 11 and the second opening 12, and an intermediate position K between the first opening 11 and the second opening 12. The second bridge 22 is arranged on the second opening 12 side.

  A plurality of first bridges 21 and second bridges 22 are arranged at a predetermined pitch in the circumferential direction of the shaft body 30, are provided so as to protrude outward, and are joined to the inner surface of the cylinder 10. Yes.

  The same material as that of the first bridge 21 and the second bridge 22 is joined to the inner peripheral surface of the cylindrical tube body 10 and the outer peripheral surface of the columnar shaft body 30 in the form of a film. The bridge 21 and the second bridge 22 can be firmly joined.

  Thus, in the dynamic damper, the first bridge 21 and the second bridge 22 are provided, and the shaft body 30 is supported at two positions in the longitudinal direction, so that the posture of the shaft body 30 can be easily maintained in an appropriate posture. The degree of freedom in designing the first bridge 21 and the second bridge 22 can be increased. Accordingly, not only can a dynamic damper capable of reliably absorbing a desired vibration be provided, but the adjustment range of the shape of the first bridge 21 and the second bridge 22 can be widened, so that the shaft body 30 can be easily shared and the manufacturing cost can be reduced. Therefore, an inexpensive dynamic damper can be provided.

  In the present embodiment, the number of the first bridge 21 and the number of the second bridges 22 is three. However, the number of the first bridges 21 and the number of the second bridges 22 is not limited to three, and may be four or more. . Furthermore, if necessary, the number of the first bridges 21 and the number of the second bridges 22 is not necessarily the same, for example, the number of the first bridges 21 is three and the number of the second bridges 22 is four. In addition, as shown in FIG. 2, each first bridge 21 is provided on the same circumference of the shaft body 30, but may be shifted from each other in the longitudinal direction of the shaft body 30 as necessary. The second bridges 22 may be arranged so as to be shifted from each other in the longitudinal direction of the shaft body 30 as necessary.

  The first bridge 21 is arranged so as to be shifted in the circumferential direction of the shaft body 30 with respect to the second bridge 22 so that the first bridge 21 and the second bridge 22 do not overlap each other in a side view. It is desirable to provide it at a shifted position.

  Thus, by shifting the first bridge 21 and the second bridge 22 in a side view, the first bridge 21 and the second bridge 22 can be easily formed in a desired shape.

  That is, the dynamic damper normally forms the first bridge 21 and the second bridge 22 by injecting rubber or the like of an elastic material to be the first bridge 21 and the second bridge 22 with an injection molding machine. This is because sometimes the mold used to form the first bridge 21 and the second bridge 22 can be easily removed.

  More specifically, when the dynamic damper is formed by the injection molding machine, the cylinder body 10 is mounted on a predetermined first mold (not shown) of the injection molding machine, and the shaft body 30 is mounted on the cylinder body 10. The cylindrical body 10 and the shaft body 30 are inserted into the first mold and mounted on the first mold, and the first mold and a second mold (not shown) provided to face the first mold. The rubber to be the first bridge 21 and the second bridge 22 is injected into the gap formed by the cylinder 10, the shaft 30, the first mold, and the second mold. Yes.

  At this time, the first mold and the second mold are each provided with a plurality of molding pieces (not shown) to be inserted between the cylindrical body 10 and the shaft body 30 in a protruding shape. One molded piece provided in the second mold is inserted between two molded pieces provided in the first mold, and the first mold is provided between the two molded pieces provided in the second mold. The first bridge 21 and the second bridge 22 are formed by injection molding in a state where one molding piece provided in the mold is inserted.

  After the first bridge 21 and the second bridge 22 are formed, the injection molding machine can be removed simply by separating the first mold and the second mold as they are, and can perform complicated operations or have a complicated structure. The first bridge 21 and the second bridge 22 can be formed without using a mold.

  Note that an adhesive is applied in advance to the inner peripheral surface of the cylindrical body 10 and the outer peripheral surface of the shaft body 30, and the rubbers constituting the first bridge 21 and the second bridge 22 are joined via the adhesive. By doing so, it is possible to join firmly. The first bridge 21 and the second bridge 22 are not limited to rubber, and an appropriate elastic material can be used.

  In the injection molding machine, the first bridge 21 and the second bridge 22 are formed on the inner peripheral surface of the cylindrical body 10 and the outer peripheral surface of the cylindrical shaft body 30 with the formation of the first bridge 21 and the second bridge 22. The first bridge 21 and the second bridge 22 can be firmly joined to the cylindrical body 10 and the shaft body 30 by injection molding the same material as the film.

  The molding pieces used for forming the first bridge 21 and the second bridge 22 may be detachable from the first mold or the second mold as separate molds from the first mold and the second mold, respectively. Good.

  When the first bridge 21 is formed to be shifted in the circumferential direction of the shaft body 30 with respect to the second bridge 22, the number of the first bridges 21 and the number of the second bridges 22 are set to n, respectively. The first bridge 21 may be disposed at a position that forms an angle of 360 / n / 2 degrees with the second elastic piece 22 in the axial projection of the shaft body 30.

  That is, for example, as shown in FIG. 1, when three each of the first bridge 21 and the second bridge 22 are provided, the first bridge 21 is the second elastic piece 22 in the axial projection of the shaft body 30. And 60 degrees. In this case, as a matter of course, the second bridge 22 is positioned at an angle of 360/3/2 = 60 degrees with the first elastic piece 21 in the axial projection of the shaft body 30.

  Thus, when the first bridge 21 is disposed at a position that forms an angle of 360 / n / 2 degrees with the second elastic piece 22 in the axial projection of the shaft body 30, the structural symmetry of the dynamic damper is obtained. Therefore, the dynamic damper itself is less likely to generate unexpected vibrations, and the vibration absorption effect as expected can be easily obtained.

  In the dynamic damper of the above-described embodiment, the first bridge 21 and the second bridge 22 are formed in a quadrangular prism shape, but the first bridge 21 and the second bridge 22 are not limited to a quadrangular prism shape. As shown in a side view in FIG. 3 (a), the first bridge 21 'and the second bridge 22' are fan-shaped with the circumferential length gradually increased from the shaft body 30 'toward the cylinder body 10'. In addition, as shown in a vertical end view in FIG. 3B, the length in the length direction of the shaft body 30 ′ may be gradually shortened from the shaft body 30 ′ toward the cylinder body 10 ′. .

  That is, the shapes and sizes of the first bridges 21 and 21 ′ and the second bridges 22 and 22 ′, and the number and positions of the first bridges 21 and 22 ′ may be appropriately set according to the vibration to be absorbed.

  As shown in FIG. 3 (b), in this embodiment, the cylindrical body 10 'has a central portion in the axial direction that is recessed from both end portions to facilitate insertion into the propeller shaft. However, if necessary, the cylindrical body 10 'is provided with a slit (not shown) along the axial direction so as to be inserted into the propeller shaft as described in Japanese Patent Application Laid-Open No. 09-053686. It may be easy to do. In this case, only one slit may be provided, or a plurality of slits may be provided at predetermined intervals along the circumferential direction of the cylinders 10 and 10 ′.

  In the dynamic damper of the above-described embodiment, the shafts 30 and 30 ′ provided inside the cylinders 10 and 10 ′ are weighted. FIG. 4A is a side view, and FIG. 4B is a vertical end surface. As shown in the figure, the cylindrical body 40 is a weight having a predetermined weight, and the shaft body 60 provided inside the cylindrical body 40 is used as a mounting bracket for disposing a dynamic damper at a predetermined position. And the shaft body 60 may be connected via the first bridge 51 and the second bridge 52.

  In particular, in this embodiment, the shaft body 60 is a cylindrical body having a hollow portion, but is not limited to the case of being configured by a cylindrical body. For example, as shown in FIG. In addition, a plate-like mounting piece 62 is provided at each end, an insertion hole 63 into which a bolt or the like is inserted is provided in the mounting piece 62, and a fixing bracket such as a bolt inserted into the insertion hole 63 is used. It may be attachable to a predetermined position.

  In this case, similarly to the dynamic damper shown in FIG. 4, the cylinder body 40 has a weight having a predetermined weight, and the cylinder body 40 and the shaft body 61 provided inside the cylinder body 40 are connected to the first bridge 51 and The second bridge 52 is connected.

  Further, the cylinder 40 itself is not used as a weight, but as shown in a side view in FIG. 6 (a) and a vertical end view in FIG. 6 (b), the cylindrical body 40 ′ has a predetermined outer peripheral surface. A cylindrical weight 70 having a weight of 1 mm may be attached by using fitting or an adhesive.

  That is, a cylindrical shaft body 60 ′ serving as a mounting bracket is arranged inside the cylindrical body 40 ′, and a plurality of first bridges 51 ′ and second bridges 52 ′ are formed to form the cylindrical body 40 ′ and the shaft body 60. After that, the weight 70 is attached to the cylindrical body 40 '.

  The shaft body 60 ′ may not be a cylindrical body, but may be a columnar shaft body 61 provided with attachment pieces 62 each provided with an insertion hole 63, as shown in FIG.

(A) The side view of the dynamic damper concerning embodiment of this invention, (b) The same longitudinal end view. It is explanatory drawing by the perspective view of the dynamic damper concerning embodiment of this invention. The dynamic damper according to the embodiment of the present invention (A) The side view of the dynamic damper of other embodiment, (b) The same longitudinal end view. It is a vertical end view of the dynamic damper of other embodiment. (A) The side view of the dynamic damper of other embodiment, (b) The same longitudinal end view. (A) The side view of the conventional dynamic damper, (b) It is the same longitudinal end view. It is a side view of the conventional dynamic damper. (A) The side view of the conventional dynamic damper, (b) It is the same longitudinal end view. It is a vertical end view of the conventional dynamic damper.

Explanation of symbols

10,10 ', 40,40' cylinder
11 1st opening
12 Second opening
20 bridge
21,21 ', 51,51' 1st bridge
22,22 ', 52,52' 2nd bridge
30,30 ', 60,60', 61 Shaft
62 Mounting piece
63 Insertion hole
70 weights

Claims (3)

A cylinder having a first opening at one end and a second opening at the other end;
A rod-shaped shaft inserted into the cylinder;
An elastic bridge that joins one side to the inner side surface of the cylindrical body and joins the other side to the outer side surface of the shaft body to connect the cylindrical body and the shaft body; and the cylindrical body and the shaft In a dynamic damper with one of the body weights,
A dynamic damper comprising a first bridge disposed closer to the first opening than an intermediate position between the first opening and the second opening, and a second bridge disposed closer to the second opening. A plurality of the first bridges and the second bridges are disposed as predetermined pitches in the circumferential direction of the shaft body, and
The dynamic damper according to claim 1, wherein the first bridge is arranged so as to be shifted in the circumferential direction of the shaft body with respect to the second bridge. The number of the first bridges and the number of the second bridges are n, respectively.
3. The dynamic damper according to claim 2, wherein the first bridge is disposed at a position that forms an angle of 360 / n / 2 degrees with the second elastic piece in an axial projection of the shaft body.

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