JP5095577B2 - Anti-vibration connecting rod - Google Patents

Description

  The present invention relates to an anti-vibration connecting rod that can be used as, for example, a torque rod for connecting an automobile engine to a vehicle body while preventing vibration.

  An anti-vibration connecting rod called a torque rod is provided between an automobile body and an engine which is a vibration generation source in order to suppress movement and vibration in the roll direction of the engine. Such an anti-vibration connecting rod generally includes a pair of anti-vibration rods provided in each cylindrical portion of the rod body, including a rod body having cylindrical portions at both ends in the longitudinal direction, an inner cylindrical bracket and a rubber-like elastic portion. A bush, and is attached to the engine or the vehicle body using the inner cylinder fitting as an attachment member.

  In recent years, there has been a strong demand for weight reduction of automobiles, and it has been proposed that the rod body be formed of a resin material as a means for reducing the weight (see Patent Document 1 below). When the rod body is made of a resin material, the vibration isolating bush provided in the cylindrical portion on the large-diameter side in particular is composed of an inner cylinder fitting and an anti-vibration base made of a rubber elastic body vulcanized on the outer periphery thereof. The rod body is injection-molded by setting it in a mold, and is integrally coupled and held in the cylindrical portion. In the vibration-proof bushing that does not have such an outer cylinder fitting, when an excessive load is input in the tensile direction (the direction in which the vibration-proof bushes at both ends are separated) in the longitudinal direction of the torque rod, the large-diameter resin tubular portion There is a problem that cracks are formed and the durability is inferior.

  The problem of durability can be solved by adding an outer cylinder fitting to the vibration-proof bushing and coupling and holding it within the resin cylindrical portion via the outer cylinder fitting. However, in this case, if a simple circular cylinder is used as the outer cylinder fitting, when an excessive load is applied and a force in the rotational direction acts on the outer cylinder fitting, the gap between the outer cylinder fitting and the cylindrical portion is reduced. There is a problem that the joint breaks.

In Patent Document 2 below, in order to prevent such damage due to rotation of the outer cylinder fitting, a recess or a projection is provided in the circumferential direction and part of the axial direction of the outer cylinder fitting, or the outer peripheral surface of the outer cylinder fitting It has been proposed that a surface shape for preventing rotation different from the curved surface of the general part is added to at least a part of the surface. As a result, the effect of preventing rotation of the outer cylinder fitting is obtained, but the configuration of the concave and convex portions provided in the circumferential direction and part of the axial direction of the outer cylinder fitting as in the same document makes the shape of the outer cylinder fitting complicated. Cost.
Japanese Patent Laid-Open No. 8-233030 JP 2006-292074 A

  The present invention has been made in view of the above points, and an object thereof is to provide a vibration-proof connecting rod that is excellent in durability and low in cost.

  The vibration-isolating connecting rod according to the present invention includes a rod body made of a resin material having a first cylindrical portion at one end and a second cylindrical portion at the other end, and a first body provided in the first cylindrical portion. An anti-vibration bush and a second anti-vibration bush provided in the second cylindrical portion, and the first anti-vibration bush is arranged in an axially parallel manner in the first cylindrical portion. A metal fitting, an outer cylinder metal fitting that surrounds the inner cylinder metal fitting in an axially parallel manner, and an anti-vibration base made of a rubber-like elastic body that is interposed between the inner cylinder metal fitting and the outer cylinder metal fitting to connect them. The anti-vibration base is connected and supported between the inner tube fitting and the outer tube fitting on both sides of the inner tube fitting in a direction perpendicular to the opposing direction of the first tubular portion and the second tubular portion. A direction perpendicular to the facing direction rather than a difference in the facing direction. Definitive form a large non-circular cross section of the tubular towards the across, characterized in that the coupled held by the first cylindrical portion by injection molding of the rod body.

  According to the above configuration, since the outer cylindrical fitting has a cylindrical shape with a non-circular cross section, the outer cylindrical fitting coupled and held in the first cylindrical portion is prevented from rotating in the circumferential direction to improve durability. Can do. Moreover, since the outer metal fitting is set to have a large difference in the direction perpendicular to the opposing direction in which the elastic coupling portion of the vibration isolating base is provided, the length of the elastic coupling portion is increased to increase the length of the vibration isolating base. Durability can also be improved. Therefore, the durability of the vibration-proof base can be improved while providing the anti-rotation function due to the shape of the outer cylindrical fitting. In addition, with such a non-circular cylindrical body, the shape of the outer cylinder fitting is simplified as compared with the case where the conventional outer cylinder fitting is provided with recesses or projections in the circumferential direction and part of the axial direction. Cost.

In the vibration-isolating connecting rod according to the present invention, the outer cylinder fitting is bent into a diameter-enlarged cylinder part or a diameter-reduced cylinder part in which both end parts in the axial direction are expanded or reduced in diameter than the central part in the axial direction through a step part. It is formed composed. In this way, by providing the enlarged diameter cylindrical portion or the reduced diameter cylindrical portion via the stepped portions at both ends of the outer cylindrical fitting, it is possible to prevent the outer cylindrical fitting from coming off from the first cylindrical portion in the axial direction. At the same time, the strength of the outer tube fitting itself can be increased.

  In the vibration-isolating connecting rod, the outer peripheral surface of the outer cylindrical metal fitting is covered with an elastic film made of a rubber-like elastic body, and the outer peripheral surface of the outer cylindrical metal fitting is inside the first cylindrical portion via the elastic film. You may join to a surrounding surface. In this way, by interposing the elastic film between the outer cylindrical fitting and the first cylindrical portion made of resin, the difference in expansion coefficient between the resin and the metal is absorbed, and the outer cylindrical fitting and the first cylindrical portion are The bonding strength between the two can be increased.

  ADVANTAGE OF THE INVENTION According to this invention, the anti-vibration coupling rod excellent in durability can be provided at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  1 to 5 show a torque rod (upper torque rod) 10 which is a vibration-proof connecting rod according to an embodiment. The torque rod 10 is assembled between the body of an automobile and an engine that is a vibration generation source, and suppresses movement and vibration in the roll direction of the engine.

  The torque rod 10 is provided in the first cylindrical portion 12 with a rod body 16 provided with a first cylindrical portion 12 having a large diameter and a second cylindrical portion 14 having a small diameter at both ends in the longitudinal direction L. The first vibration isolating bush 18 and the second vibration isolating bush 20 provided in the second cylindrical portion 14.

  The rod main body 16 includes the first cylindrical portion 12, the second cylindrical portion 14, and a main body connecting portion 22 that extends in the longitudinal direction L that connects both the cylindrical portions 12 and 14, which are made of polyamide or the like. It is integrally formed of a thermoplastic resin material. The first cylindrical portion 12 and the second cylindrical portion 14 are provided with their axes O1 (see FIG. 5) and O2 (see FIG. 4) perpendicular to the longitudinal direction L of the rod body 16, and the first cylindrical portion. The axis O1 of the part 12 and the axis O2 of the second cylindrical part 14 are also provided vertically.

  The main body connecting portion 22 is provided with a plurality of (here, three) reinforcing ribs 24 extending in the longitudinal direction L. These reinforcing ribs 24 extend from the main body connecting portion 22 toward the first cylindrical portion 12, and are provided over the entire circumference on the outer peripheral surface of the first cylindrical portion 12. Reference numeral 26 denotes an injection gate serving as a molten resin injection port when the rod body 16 is injection-molded.

  The first anti-vibration bush 18 provided in the first cylindrical portion 12 includes a first inner cylindrical fitting 28 arranged in parallel in the first cylindrical portion 12 and an axial parallel of the first inner cylindrical fitting 28. And a first anti-vibration base 32 made of a rubber elastic body interposed between the first inner cylinder fitting 28 and the outer cylinder fitting 30 to connect them.

  Further, the second vibration isolating bush 20 provided in the second cylindrical portion 14 having a smaller diameter than the first cylindrical portion 12 is a second inner cylindrical metal fitting 34 disposed in the second cylindrical portion 14 in an axially parallel manner. And a second anti-vibration base 36 made of a rubber elastic body interposed between the second inner cylindrical fitting 34 and the second cylindrical portion 14.

  The second cylindrical portion 14 has a circular cross section, and a second inner cylindrical fitting 34 is provided on the axis O2. The second vibration isolation base 36 is a cylindrical rubber member provided over the entire circumference between the second inner cylindrical fitting 34 and the second cylindrical portion 14, and is vulcanized and bonded to the outer peripheral surface of the second inner cylindrical fitting 34. Has been. Then, the second vibration isolating bush 20 having the second vibration isolating base 36 vulcanized and formed on the outer periphery of the second inner cylindrical metal fitting 34 is press-fitted in the axial direction with respect to the second cylindrical portion 14 of the rod body 16. It is installed by.

  On the other hand, the first vibration isolating bush 18 is coupled and held in the first cylindrical portion 12 by injection molding of the rod body 16. That is, after the first vibration-proof base 32 is vulcanized and molded between the first inner cylinder fitting 28 and the outer cylinder fitting 30, the vulcanized molded body is set in an injection mold, and the resin material is injected from the injection gate 26. By injection molding, the rod body 16 is formed integrally with the first vibration isolating bush 18, and thereby, the outer cylinder fitting 30 is configured to be coupled and held in the first cylindrical portion 12.

  As shown in FIG. 2, the outer cylindrical fitting 30 of the first vibration isolating bush 18 is different in the opposing direction of the first cylindrical portion 12 and the second cylindrical portion 14 (that is, the longitudinal direction L of the main body connecting portion 22). The cross section D2 in the direction M perpendicular to the longitudinal direction L is larger than the cross section D1, and has a cylindrical shape with a non-circular cross section. In this example, the cross section (that is, the diameter) D1 in the longitudinal direction L is smaller than the cross section (that is, the diameter) D2 in the direction M perpendicular to the longitudinal direction. The oval shape may be a track shape composed of two opposing semicircular portions and a pair of linear portions connecting between the two semicircular portions as shown in FIG. 6, or may be an elliptical shape.

  Further, as shown in FIGS. 7 and 8, the outer tube fitting 30 has an enlarged cylindrical portion 38 in which both axial end portions 30A and 30A are larger in diameter than the axial central portion 30C via stepped portions 30B and 30B. , 38 are bent. The enlarged diameter cylindrical portion 38 is formed over the entire circumference at both axial end portions 30 </ b> A and 30 </ b> A of the outer cylindrical fitting 30. Thereby, the outer cylinder fitting 30 is formed in a concave shape in which the axial center portion 30 </ b> C is depressed inward in the direction perpendicular to the axis in the cross-sectional shape along the axial direction X.

  A rectangular opening window 40 penetrating the inside and the outside is provided on the side wall on the main body connecting portion 22 side in the axial center portion 30C of the outer cylinder fitting 30 (see FIGS. 5, 7, and 8). As a result, an outer peripheral surface 30 </ b> D of the outer cylinder fitting 30 is covered with an elastic film 42 made of a rubber elastic body that is continuous with the first vibration isolation base 32. As shown in FIGS. 4 and 7, the elastic film 42 is formed on the outer peripheral surface 30 </ b> D of the outer tube fitting 30 with the axial center portion 30 </ b> C, the step portions 30 </ b> B and 30 </ b> B on both sides thereof, and the outer diameter-enlarged tube portions 38 and 38. It is formed over substantially the whole of the axial direction X including a part of it, and over the entire circumference in the circumferential direction. However, the tip ends of both axial end portions 30A and 30A are exposed without being covered with the elastic film 42. By providing the elastic film 42 in this way, as shown in FIGS. 4 and 5, the outer cylindrical member 30 has its outer peripheral surface 30 </ b> D joined to the inner peripheral surface of the first cylindrical portion 12 via the elastic film 42. Has been.

  As shown in FIG. 2, the first anti-vibration base 32 of the first anti-vibration bush 18 has a first inner cylinder fitting 28 on both sides of the first inner cylinder fitting 28 in the direction M perpendicular to the longitudinal direction L. And a pair of upper and lower elastic connecting portions 44, 44 that connect and support the outer cylindrical fitting 30. Specifically, as shown in FIGS. 6 and 7, the first vibration isolation base 32 includes a pair of hollow portions 46 that penetrate in the axial direction X on both sides of the first inner cylindrical fitting 28 in the longitudinal direction L. 46, whereby a pair of upper and lower elastic connecting portions 44, 44 connecting the pair of upper and lower side surfaces of the first inner cylinder fitting 28 and the upper and lower inner peripheral surfaces of the outer cylinder fitting 30 opposed thereto are provided. Is provided. In other words, the elastic connecting portion 44 connects the first inner cylinder fitting 28 and the outer cylinder fitting 30 on the larger delivery D2 side of the outer cylinder fitting 30.

  The pair of cavities 46, 46 are provided with stopper rubber portions 48, 50, respectively. The stopper rubber portion 48 on the main body connecting portion 22 side has two straight portions 52 in the axial direction X having a circular cross section. One is provided.

  In the torque rod 10 constructed as described above, the first inner cylinder fitting 28 is connected to either the vehicle body or the engine, and the second inner cylinder fitting 34 is connected to either the vehicle body or the engine. Specifically, in this example, the longitudinal direction L is the front-rear direction, and the direction M perpendicular to the longitudinal direction L is the up-down direction, and the first inner cylinder fitting 28 is on the engine side and the second inner cylinder fitting 34 is on the vehicle body side. Combined.

  In the torque rod 10 of the present embodiment, the outer cylinder fitting 30 of the first vibration isolating bush 18 on the large diameter side has a cylindrical shape with an oval cross section, and is thus coupled and held in the first cylindrical portion 12. Further, rotation of the outer tubular fitting 30 in the circumferential direction can be prevented. Therefore, it is possible to improve the durability by preventing adhesion failure between the outer tubular fitting 30 and the first tubular portion 12.

  In addition, since the outer cylinder fitting 30 has a large difference in the direction M perpendicular to the longitudinal direction L in which the elastic connection portion 44 of the first vibration isolation base 32 is provided (D2> D1), the elastic connection The durability of the first vibration isolation base 32 can be improved by increasing the length of the portion 44.

  Therefore, the durability of the first anti-vibration base 32 can be improved while the anti-rotation function is provided by the shape of the outer cylinder fitting 30. In addition, since the rotation preventing function can be provided with a relatively simple shape of a cylindrical body having an oval cross section, the cost can be reduced.

  The cross-sectional shape of the outer cylinder fitting 30 is not limited to such an oval shape (track shape, oval shape), and various noncircular shapes such as a rectangular shape with rounded corners are applied. be able to.

  In the torque rod 10 of the present embodiment, since the diameter-expanded cylindrical portions 38 and 38 are provided at both axial end portions 30A and 30A of the outer cylindrical fitting 30 via the step portions 30B and 30B, respectively. The outer tubular fitting 30 can be prevented from coming off from the first tubular portion 12. Further, by adopting such a bent shape, it is possible to increase the strength of the outer tubular fitting 30, and it is possible to improve durability from this point.

  Instead of providing the diameter-expanded cylindrical portion 38, a diameter-reduced cylindrical portion having a diameter smaller than that of the central portion in the axial direction may be bent at both end portions in the axial direction of the outer cylinder fitting. Thereby, the outer cylinder fitting is formed in a convex shape in which the central portion in the axial direction swells outward in the direction perpendicular to the axis in the cross-sectional shape along the axial direction. Even when such a reduced diameter cylindrical portion is provided, it is possible to prevent the outer cylinder fitting from coming off and increase the strength, as in the case where the enlarged diameter cylindrical portion 38 is provided.

  In the torque rod 10 of the present embodiment, the elastic film 42 is interposed between the outer tubular fitting 30 and the first cylindrical portion 12 made of resin, so that the difference in expansion coefficient between the resin and the metal is reduced. It can be absorbed by the elastic film 42 to increase the bonding strength between the outer tubular fitting 30 and the first cylindrical portion 12, and the durability can be improved also in this respect.

  In the above-described embodiment, the configuration in which the outer cylindrical metal fitting 30 is provided only in the first vibration isolating bush 18 provided in the first cylindrical portion 12 is employed, but the second cylindrical portion 14 on the small diameter side is provided. A similar configuration may be employed in the second vibration-proof bushing. Further, in addition to the torque rod, it can be applied as various anti-vibration connecting rods such as a stabilizer link rod and a suspension rod. Although not enumerated one by one, various modifications can be made without departing from the spirit of the present invention.

The perspective view of the vibration isolating connecting rod which concerns on embodiment Side view of the anti-vibration connecting rod Plan view of the anti-vibration connecting rod Sectional view taken along line IV-IV in FIG. VV sectional view of FIG. Side view of the first anti-vibration bush of the anti-vibration connecting rod VII-VII line sectional view of FIG. Perspective view of the outer cylinder fitting of the first anti-vibration bush

Explanation of symbols

10 ... Torque rod (anti-vibration connecting rod)
DESCRIPTION OF SYMBOLS 12 ... 1st cylindrical part 14 ... 2nd cylindrical part 16 ... Rod main body 18 ... 1st anti-vibration bush 20 ... 2nd anti-vibration bush 28 ... 1st inner cylinder metal fitting (inner cylinder metal fitting)
DESCRIPTION OF SYMBOLS 30 ... Outer cylinder metal fitting, 30A ... Axial direction edge part, 30B ... Step part, 30C ... Axial direction center part, 30D ... Outer peripheral surface 32 ... 1st vibration proof base (vibration proof base)
38 ... Diameter-expanded cylindrical part 42 ... Elastic film L ... Longitudinal direction (opposite direction of the first cylindrical part and the second cylindrical part)
M: direction perpendicular to the longitudinal direction (opposite direction) D1: difference in the longitudinal direction of the outer cylinder fitting D2: difference in the direction perpendicular to the longitudinal direction of the outer cylinder fitting

Claims (3)

A rod body made of a resin material having a first cylindrical part at one end and a second cylindrical part at the other end;
A first vibration isolating bush provided in the first tubular portion;
A second anti-vibration bush provided in the second tubular portion;
With
The first anti-vibration bush includes an inner cylinder fitting arranged in an axial parallel in the first cylindrical portion, an outer cylinder fitting surrounding the inner cylinder fitting in an axis parallel, and between the inner cylinder fitting and the outer cylinder fitting. An anti-vibration base made of a rubber-like elastic body interposed between the two and connecting the two,
The anti-vibration base is connected and supported between the inner tube fitting and the outer tube fitting on both sides of the inner tube fitting in a direction perpendicular to the opposing direction of the first tubular portion and the second tubular portion. Having a pair of elastic coupling parts,
The outer cylinder fitting has a cylindrical shape with a non-circular cross section in which the difference in the direction perpendicular to the facing direction is larger than the difference in the facing direction, and the first tubular shape is formed by injection molding of the rod body. Is held in the joint ,
The outer cylinder fitting is formed by bending both ends in the axial direction into a diameter-enlarged cylinder part or a diameter-reduced cylinder part whose diameter is larger or smaller than the center part in the axial direction through a step part. Vibration connecting rod. The outer cylinder metal fitting anti-vibration connecting rod of claim 1 wherein the form of an oval cross section of the tubular. The outer peripheral surface of the outer tubular metal fitting is covered with an elastic film made of a rubber-like elastic body, and the outer peripheral surface of the outer cylindrical metal fitting is joined to the inner peripheral surface of the first cylindrical portion via the elastic film. The anti-vibration connecting rod according to 1 or 2 .

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