JP7555879B2 - Anti-vibration device - Google Patents

Description

The present invention relates to an anti-vibration device, and in particular to an anti-vibration device that can improve the workability of installing the stopper rubber while preventing the stopper rubber from falling off.

There is a known technology for attaching a stopper rubber to a rubber film that covers the outer circumferential surface of an inner tube. For example, Patent Document 1 describes a technology in which a recess 7 is formed on the outer circumferential surface of the rubber film, while a protrusion 8 is formed on the inner circumferential surface of the side stopper 5 (stopper rubber), and the protrusion 8 is fitted into the recess 7 to attach the side stopper 5 to the inner tube 1.

JP-A-05-118367 (for example, paragraphs 0011 and 0012, FIG. 5)

However, in the conventional technology described above, although the side stopper 5 is relatively unlikely to fall off due to the engagement between the recess 7 and the protrusion 8, there is a problem in that it is difficult to fit the protrusion 8 into the recess 7 to attach the stopper rubber.

The present invention has been made to solve the above-mentioned problems, and aims to provide a vibration-damping device that can improve the workability of installing the stopper rubber while preventing the stopper rubber from falling off.

In order to achieve this object, the vibration-damping device of the present invention comprises a cylindrical outer tube fixed to a first member constituting either the support side or the vibration source side, a vibration-damping base made of a rubber-like elastic material connected to the inner peripheral surface of the outer tube, a cylindrical inner tube which is arranged on the inner peripheral side of the outer tube by connecting the vibration-damping base to the outer peripheral surface thereof and which is fixed to a second member constituting the other of the support side or the vibration source side, a rubber membrane made of a rubber-like elastic material covering the outer peripheral surface of the axial end side of the inner tube, and a rubber membrane attached to the outer peripheral surface of the rubber membrane and configured to prevent collision between the first member or the outer tube and the second member. and an annular stopper rubber that absorbs impacts during impact, the stopper rubber has a recess that is recessed into the axially outer end of the inner peripheral surface of the stopper rubber, the rubber film has a protrusion that protrudes from the outer peripheral surface of the rubber film toward the recess and is fitted into the recess, the protrusion has a first inclined surface that decreases in diameter from the top of the protrusion toward the axially inner side, and a second inclined surface that decreases in diameter from the top of the protrusion toward the axially outer side, and the inclination of the first inclined surface with respect to the axial direction is greater than the inclination of the second inclined surface with respect to the axial direction.

The vibration-proof device of claim 1 has the following effects. The stopper rubber has a recessed portion recessed into the axially outer end of its inner peripheral surface, and the rubber film has a protrusion protruding from its outer peripheral surface toward the recessed portion and fitted into the recessed portion. The protrusion has a first inclined surface that decreases in diameter from its top toward the axially inner side, and a second inclined surface that decreases in diameter from the top of the protrusion toward the axially outer side, so that the first inclined surface of the protrusion catches with the recessed portion of the stopper rubber, preventing the stopper rubber from falling off.

Since the inclination of the first inclined surface relative to the axial direction is greater than the inclination of the second inclined surface, the above-mentioned stopper rubber can be effectively prevented from falling off. On the other hand, since the inclination of the second inclined surface relative to the axial direction is smaller than the inclination of the first inclined surface, the resistance caused by the second inclined surface when inserting the inner tube (rubber membrane) into the stopper rubber can be reduced. This has the effect of preventing the stopper rubber from falling off while improving the workability of attaching the stopper rubber.

According to the vibration-proof device of claim 2, in addition to the effect of the vibration-proof device of claim 1, the following effect is achieved. When the stopper rubber is attached with the convex portion fitted into the concave portion, the top of the convex portion is not in contact with the inner surface of the concave portion, so it is easy to determine whether the convex portion is fitted into the concave portion. That is, when the stopper rubber is attached, for example, if the top of the convex portion is configured to contact the inner surface of the concave portion, the top of the convex portion will be in contact with the inner surface of the concave portion both during the insertion of the inner tube (rubber film) into the stopper rubber and at the insertion completion position where the convex portion fits into the concave portion. Therefore, it is difficult to change the feel (resistance) when inserting the inner tube into the stopper rubber, making it difficult to get a feel for whether the convex portion is fitted into the concave portion.

In contrast, the configuration of claim 2 makes it possible to increase the change in feel (resistance) between when the inner tube is being inserted into the stopper rubber and when the convex portion fits into the concave portion, making it easy to determine whether the convex portion is fitted into the concave portion. This has the effect of improving the workability of attaching the stopper rubber.

According to the vibration-proof device of claim 3, in addition to the effects of the vibration-proof device of claim 1 or 2, the following effect is achieved. The first inclined surface is a curved surface that is concave toward the inner tube in a cross-sectional view cut along a plane including the axis, and the inner surface of the recess that contacts the first inclined surface is a curved surface that follows the first inclined surface. This ensures a large contact area between the first inclined surface of the convex portion and the inner surface of the recess, while increasing the resistance due to friction therebetween, thereby preventing the convex portion from coming off the recess. This has the effect of preventing the stopper rubber from falling off.

According to the vibration-proof device of claim 4, in addition to the effect of the vibration-proof device of any one of claims 1 to 3, the following effect is achieved. The convex portion is formed at one location on a part of the rubber film in the circumferential direction, or at multiple locations on the rubber film in the circumferential direction, and the inner surface of the concave portion facing the circumferential direction contacts the convex portion, so that the rotation of the stopper rubber in the circumferential direction can be restricted by the engagement between the concave portion and the convex portion. Therefore, there is an effect that the stopper rubber can be positioned in the circumferential direction.

The vibration-damping device of claim 5 has the following effect in addition to the effect of the vibration-damping device of claim 4. Since the convex portion is formed at one location in a portion of the rubber film in the circumferential direction, even if the first inclined surface is undercut when vulcanizing the convex portion (rubber film), the removability of the convex portion can be ensured. Therefore, even if the inclination of the first inclined surface with respect to the axial direction is greater than the inclination of the second inclined surface, the rubber film having the convex portion can be easily vulcanized.

According to the vibration-proof device of claim 6, in addition to the effects of the vibration-proof device of any one of claims 1 to 5, the following effects are achieved. The stopper rubber is attached to the outer peripheral surface of the inner tube, and includes a cylindrical tube portion having a recess formed on the inner peripheral surface, and a protruding portion that protrudes radially from the outer peripheral surface of the tube portion to absorb the impact when the first member or the outer tube collides with the second member. The tube portion has a groove formed on its inner peripheral surface and extending axially outward from the axially inner end of the inner peripheral surface of the tube portion, and the rubber film has a protruding portion that protrudes radially outward from its outer peripheral surface and is fitted into the groove. As a result, by inserting the protruding portion into the groove from the axial direction, the insertion of the inner tube into the tube portion of the stopper rubber can be guided, which has the effect of improving the workability of attaching the stopper rubber. Furthermore, after the stopper rubber is attached, the rotation of the stopper rubber can be restricted by the circumferential engagement between the groove and the protruding portion.

The vibration-proof device of claim 7 has the following effect in addition to the effect of the vibration-proof device of claim 6. The protrusion extends axially inward from a position where the protrusion overlaps with a virtual plane that includes the convex portion and is perpendicular to the axis, so that the engagement length between the protrusion and the groove can be secured to be long in the axial direction. This improves the retention force of the stopper rubber due to the engagement between the protrusion and the groove, and has the effect of suppressing the stopper rubber from falling off.

The vibration-proof device of claim 8 has the following effect in addition to the effect of the vibration-proof device of claim 7. The tubular portion has a blocking portion that blocks the axially outer end of the groove, so the amount of rubber at the axially outer end of the tubular portion can be secured by the blocking portion. This makes it possible to suppress deformation of the tubular portion at the axially outer portion of the tubular portion, i.e., the region where the recess is formed, and therefore prevents the protrusion from coming off the recess. This has the effect of suppressing the stopper rubber from falling off.

According to the vibration-proof device of claim 9, in addition to the effect of the vibration-proof device of any one of claims 6 to 8, the following effect is achieved. The protruding portion has a notch portion formed with a radial dimension smaller than that of other portions, and the inner peripheral surface of the inner tube is formed in an elliptical shape for fixing the inner tube to the second member with the notch portion facing a predetermined direction. This predetermined direction is a direction in which there is a concern that the stopper rubber may come into contact with other surrounding parts when the inner tube (stopper rubber) is displaced by the input of vibration.

If a recess is formed near the area where the notch or groove is formed, the protrusion will easily come out of the recess. This is because the amount of rubber is reduced in the area where the notch or groove is formed, making it easier for deformation to occur in the stopper rubber. In contrast, in claim 9, the recess, groove, and notch are each formed in different positions in the circumferential direction, so the recess can be positioned in a position that avoids the area where the groove or notch is formed. This has the effect of preventing the stopper rubber from falling off, as the protrusion will not easily come out of the recess, even if a groove or notch is formed in the stopper rubber.

The vibration-isolating device of claim 10 has the following effects in addition to those of the vibration-isolating device of claim 9. The convex portion and the protruding portion are formed on the rubber film covering the outer peripheral surface of one axial end of the inner tube, and on the rubber film covering the outer peripheral surface of the other axial end. The concave portion and the groove are formed in positions that allow stopper rubbers of the same shape to be attached to both axial ends of the inner tube, so that the stopper rubbers attached to both axial ends of the inner tube can be molded using a common mold. Furthermore, because only one type of stopper rubber is attached to the inner tube, there is an effect that the stopper rubbers can be prevented from being attached incorrectly.

According to the vibration-proof device of claim 11, in addition to the effects of the vibration-proof device of claim 9 or 10, the following effect is achieved. Since the protrusion protrudes along the long axis direction of the elliptical inner peripheral surface of the inner tube, the orientation of the elliptical shape of the inner peripheral surface of the inner tube can be easily recognized by the protrusion. This makes it easy to grasp the orientation of the inner tube (the posture in which it should be attached) when fixing the inner tube to the second member, which has the effect of improving the workability of assembling the inner tube to the second member.

1 is an exploded perspective view of an anti-vibration device according to an embodiment of the present invention; FIG. 4 is a cross-sectional view showing an assembled state of the vibration isolation device. 3A is a partially enlarged cross-sectional view of the vibration isolation device obtained by enlarging a portion IIIa in FIG. 2, and FIG. 3B is a partially enlarged cross-sectional view of the vibration isolation device taken along line IIIb-IIIb in FIG. 3A. 4 is a cross-sectional view showing an assembled state of the vibration isolation device taken along line IV-IV in FIG. 2. 5A is a top view of the vibration isolation device as viewed in the axial direction, and FIG. 5B is a side view of the vibration isolation device as viewed in the direction of arrow Vb in FIG. 5A. 6A is a top view of the stopper rubber as viewed in the axial direction, and FIG. 6B is a cross-sectional view of the stopper rubber taken along line VIb-VIb in FIG. 6A.

Below, preferred embodiments of the present invention will be described with reference to the attached drawings. First, the configuration of the vibration isolation device 1 will be described with reference to Figs. 1 and 2. Fig. 1 is a cross-sectional view of the vibration isolation device 1 in one embodiment of the present invention, and Fig. 2 is a cross-sectional view showing the assembled state of the vibration isolation device 1. Note that Fig. 2 illustrates a cross-section cut along a plane along the axis O of the vibration isolation device 1.

In the following description, both ends of the vibration isolation device 1 in the axial O direction (upper and lower sides in Figures 1 and 2) are referred to as the "outer side in the axial O direction", the center side of the vibration isolation device 1 in the axial O direction is referred to as the "inner side in the axial O direction", the direction perpendicular to the axis O is referred to as the "radial direction", and the direction around the axis O is referred to as the "circumferential direction".

As shown in Figures 1 and 2, the vibration isolation device 1 is an anti-vibration device for suppressing the transmission of vibration from a vibration source (not shown) such as an automobile motor or engine to a support (not shown) such as a vehicle body. The vibration isolation device 1 includes an outer tube 2 that is attached to the support side via a first bracket 100 (see Figure 2). Note that the outer tube 2 may be attached to the vibration source side (with the inner tube 4, described later, attached to the support side).

The outer cylinder 2 is formed into a cylindrical shape using a metal material such as an aluminum alloy. The vibration isolation device 1 is attached to the first bracket 100 by pressing the outer cylinder 2 into the press-fit hole 101 (see FIG. 2) of the first bracket 100.

A vibration-isolating base 3 made of a rubber-like elastic body is vulcanized and bonded to the inner peripheral surface of the outer tube 2, and the inner tube 4 is connected to the inner peripheral side of the outer tube 2 via this vibration-isolating base 3. The vibration-isolating base 3 comprises a connecting portion 30 that connects the outer tube 2 and the inner tube 4 in the radial direction, and a membrane portion 31 that is connected to the connecting portion 30 and covers the outer peripheral surface of the inner tube 4, and these connecting portion 30 and membrane portion 31 are formed continuously in the circumferential direction. The membrane portion 31 extends outward from the connecting portion 30 in the axial O direction and covers almost the entire outer peripheral surface of the inner tube 4.

The inner tube 4 is a member fixed to the second bracket 200 on the vibration source side. The inner tube 4 is formed into a cylindrical shape using a metal material such as an aluminum alloy, and is arranged coaxially with the outer tube 2. The inner tube 4 is fastened and fixed to the second bracket 200 by an axial member 300 inserted into the inner circumference of the inner tube 4. Note that the axial member 300 can be, for example, a fastening means such as a bolt or a rivet, but FIG. 2 shows it diagrammatically, omitting the illustration of the fastening structure using the axial member 300.

By attaching the inner tube 4 to the second bracket 200 (vibration source side), the vibration source is supported by the support (first bracket 100) via the vibration isolation device 1. When the second bracket 200 is displaced in the axial O direction due to vibration of the vibration source, the second bracket 200 may come into contact with the outer tube 2 (first bracket 100). A stopper rubber 5 is attached to the inner tube 4 to reduce the impact (noise) that occurs when such contact occurs.

The stopper rubber 5 is a substantially annular member having a cylindrical tube portion 50 extending in the axial direction O and a protruding portion 51 that protrudes in a flange-like shape (diametrically outward) from the outer circumferential surface of the tube portion 50. The tube portion 50 and the protruding portion 51 are integrally formed using a rubber-like elastic body.

The inner diameter of the tube portion 50 is formed to be the same as (or slightly smaller than) the outer diameter of the membrane portion 31, and the stopper rubber 5 is attached to the outer peripheral surface of the membrane portion 31 by inserting the inner tube 4 (membrane portion 31) from the end face 50a side on the inner side in the axial O direction of the tube portion 50. The insertion of the inner tube 4 into the tube portion 50 is guided by the protrusion 32 (see FIG. 1 or FIG. 5) protruding from the membrane portion 31 and the groove 52 (see FIG. 1) formed in the stopper rubber 5.

The protruding portion 32 protrudes radially outward from the outer peripheral surface of the membrane portion 31, and is vulcanized integrally with the membrane portion 31 (vibration-proof base 3). On the other hand, a groove 52 into which the protruding portion 32 is fitted is formed on the inner peripheral surface of the tube portion 50 of the stopper rubber 5. The groove 52 extends from the end face 50a on the inner side of the axis O direction of the tube portion 50 to the outer side in the axis O direction, so that the protruding portion 32 can be inserted from the opening part on the inner side of the axis O direction of the groove 52 to guide the insertion of the inner tube 4 into the tube portion 50. This improves the workability of attaching the stopper rubber 5. After the stopper rubber 5 is attached, the rotation of the stopper rubber 5 can be restricted by the circumferential engagement between the groove 52 and the protruding portion 32. The restriction of the rotation of the stopper rubber 5 (positioning in the circumferential direction) is for determining the direction of the notch portion 53 (see FIG. 1) formed in the protruding portion 51, and the details of the notch portion 53 will be described later.

When the stopper rubber 5 is attached to the inner tube 4, the convex portion 33 protruding from the outer peripheral surface of the membrane portion 31 is fitted into the concave portion 54 recessed into the inner peripheral surface of the tube portion 50. This prevents the stopper rubber 5 from falling off from this attached state by the engagement between the convex portion 33 and the concave portion 54 (see Figure 2). In the following explanation, the state in which the stopper rubber 5 is attached to the inner tube 4 (membrane portion 31) and the convex portion 33 is fitted into the concave portion 54 is described as the "attached state of the stopper rubber 5".

Next, the detailed configuration of the convex portion 33 and the concave portion 54 will be described with reference to FIG. 3. FIG. 3(a) is a partially enlarged cross-sectional view of the vibration isolation device 1 enlarging the IIIa portion of FIG. 2, and FIG. 3(b) is a partially enlarged cross-sectional view of the vibration isolation device 1 taken along line IIIb-IIIb of FIG. 3(a).

As shown in FIG. 3, the protrusion 33 has a first inclined surface 33a that narrows in diameter from its apex (the radially outer end) toward the inside in the axial O direction (the lower side in FIG. 3(a)), and a second inclined surface 33b that narrows in diameter from the apex of the protrusion 33 toward the outside in the axial O direction (the upper side in FIG. 3(a)).

The first inclined surface 33a is an inclined surface that approaches the inner tube 4 as it moves inward in the direction of the axis O in a cross-sectional view cut along a plane including the axis O, and the second inclined surface 33b is an inclined surface that approaches the inner tube 4 as it moves outward in the direction of the axis O in such a cross-sectional view. The connection portion between the first inclined surface 33a and the second inclined surface 33b forms a curved surface 33c that is convex radially outward. The radially outer end of this curved surface 33c is the apex of the convex portion 33.

The recess 54 into which the protrusion 33 is fitted is formed on the inner circumferential surface of the tube portion 50 by cutting out the end face 50b on the outer side in the axial O direction. Thus, the recess 54 is formed with an inner surface 54a facing outward in the axial O direction, a pair of inner surfaces 54b facing in the circumferential direction, and an inner surface 54c facing radially inward.

By fitting the protrusion 33 into the recess 54, the first inclined surface 33a of the protrusion 33 comes into contact with the inner surface 54a of the recess 54, and the first inclined surface 33a and the inner surface 54a are caught together, preventing the stopper rubber 5 from falling off from the inner tube 4 (membrane portion 31). Since the inclination of the first inclined surface 33a is greater than the inclination (degree of inclination) of the second inclined surface 33b relative to the axial O direction, the first inclined surface 33a is more likely to catch on the inner surface 54a of the recess 54 when the stopper rubber 5 is displaced outward in the axial O direction. This effectively prevents the stopper rubber 5 from falling off.

On the other hand, since the inclination of the second inclined surface 33b with respect to the axial direction is smaller than the inclination of the first inclined surface 33a, the resistance caused by the second inclined surface 33b when inserting the inner tube 4 into the tubular portion 50 of the stopper rubber 5 can be reduced. In other words, since the taper of the second inclined surface 33b is gentle, it is easy to push the protrusion 33 into the inner periphery of the tubular portion 50. This improves the workability of installing the stopper rubber 5.

In addition, the first inclined surface 33a of the convex portion 33 is a curved surface that is concave toward the inner tube 4 side in a cross-sectional view cut along a plane including the axis O, and the inner surface 54a of the concave portion 54 is a curved surface that is convex toward the first inclined surface 33a side. This allows the inner surface 54a to come into contact along the first inclined surface 33a, so that the contact area between the first inclined surface 33a and the inner surface 54a can be made large while increasing the resistance due to friction therebetween. This makes it possible to prevent the stopper rubber 5 from falling off.

When the first inclined surface 33a is a curved surface, the "inclination (degree of inclination) with respect to the axis O" refers to the inclination with respect to the axis O of a straight line connecting the connection position (inflection point) of the outer peripheral surface of the membrane portion 31 and the first inclined surface 33a and the connection position (inflection point) of the first inclined surface 33a and the curved surface 33c in a cross-sectional view cut along a plane including the axis O.

Here, when the inner tube 4 is inserted into the inner circumference of the stopper rubber 5 (tubular portion 50), the curved surface 33c (the top of the convex portion 33) of the convex portion 33 comes into contact with the inner circumference of the tube portion 50, so resistance (the feeling when pushing the convex portion 33) occurs during this insertion. In this case, for example, if the curved surface 33c of the convex portion 33 comes into contact with the inner surface 54c of the recessed portion 54 when the stopper rubber 5 is attached, the curved surface 33c comes into contact with the inner surface 54c during insertion when the inner tube 4 is inserted into the stopper rubber 5 and at the insertion completion position where the convex portion 33 fits into the recessed portion 54. Therefore, it is difficult to change the feeling (resistance) between when the inner tube 4 is inserted into the stopper rubber 5 and when the insertion is completed, so it is difficult to get a feeling as to whether or not the insertion completion position has been reached.

In contrast, in this embodiment, the depth of the recess 54 from the inner peripheral surface of the tube portion 50 is formed deeper than the protruding dimension of the protrusion 33 from the membrane portion 31. Therefore, when the stopper rubber 5 is attached, the curved surface 33c (the top of the protrusion 33) of the protrusion 33 is not in contact with the inner surface 54c of the recess 54. This makes it possible to change the feeling (resistance) felt during the insertion of the inner tube 4 into the stopper rubber 5 and at the insertion completion position where the protrusion 33 fits into the recess 54. In other words, the insertion resistance generated by the contact between the protrusion 33 and the tube portion 50 when the inner tube 4 is inserted is released (a clicking feeling is obtained) when the insertion completion position is reached, so it is easy to determine whether the protrusion 33 is fitted into the recess 54. Therefore, the workability of attaching the stopper rubber 5 can be improved.

The vibration-proof base 3 including the protrusion 33 (the film portion 31 and the connecting portion 30 shown in FIG. 2) is vulcanized and molded as a single unit using a mold. A known mold can be used for this vulcanization molding, so a detailed description will be omitted, but such a mold generally has an upper mold and a lower mold for removing the mold in the axial O direction (see, for example, FIG. 3 of JP 2012-202460 A). When the vibration-proof base 3 is vulcanized and molded using such a mold, the first inclined surface 33a of the protrusion 33 becomes an undercut. Therefore, for example, if the protrusion 33 is formed continuously in the circumferential direction or if multiple protrusions 33 are formed in the circumferential direction, the area where the mold is forcibly removed becomes wide, and the demoldability is reduced.

In contrast, in this embodiment, the convex portion 33 is formed at only one location in the circumferential direction of the membrane portion 31, so that even if the first inclined surface 33a is undercut when the vibration-proof base 3 is vulcanized, the removability of the convex portion 33 can be ensured. In other words, even if the inclination of the first inclined surface 33a relative to the axis O direction is greater than the inclination of the second inclined surface 33b, the vibration-proof base 3 having the convex portion 33 can be easily vulcanized.

Furthermore, the convex portion 33 is formed at one location in the circumferential direction of the membrane portion 31, and when the stopper rubber 5 is attached, the convex portion 33 comes into contact with a pair of inner surfaces 54b of the recessed portion 54. This allows the pair of inner surfaces 54b to hook onto the convex portion 33, thereby restricting the rotation of the stopper rubber 5. This restriction on the rotation of the stopper rubber 5 ensures that the notch portion 53 (see FIG. 1) of the stopper rubber 5 always faces in a specified direction. This configuration will be described with reference to FIGS. 4 to 6.

Figure 4 is a cross-sectional view showing the assembled state of the vibration isolation device 1 taken along line IV-IV in Figure 2. Figure 5(a) is a top view of the vibration isolation device 1 as viewed in the direction of axis O, and Figure 5(b) is a side view of the vibration isolation device 1 as viewed in the direction of arrow Vb in Figure 5(a). Figure 6(a) is a top view of the stopper rubber 5 as viewed in the direction of axis O, and Figure 6(b) is a cross-sectional view of the stopper rubber 5 taken along line VIb-VIb in Figure 6(a). Note that Figure 5 shows the vibration isolation device 1 with the stopper rubber 5 removed.

As shown in FIG. 4, the outer diameter of the protruding portion 51 of the stopper rubber 5 is larger than the outer diameter of the outer tube 2 (the inner diameter of the press-fit hole 101) except for the portion where the notch portion 53 is formed. This is because, as described above, the protruding portion 51 covers the end portion in the axial O direction of the outer tube 2 (around the press-fit hole 101), and the protruding portion 51 reduces the impact (noise) when the outer tube 2 (first bracket 100) and the second bracket 200 come into contact.

As described above, since the protruding portion 51 protrudes in the radial direction, if the inner tube 4 is displaced in the radial direction (left and right direction in FIG. 4) when vibration is input, the protruding portion 51 may come into contact with the first bracket 100 (or other surrounding parts). A notch 53 is formed in the protruding portion 51 to prevent such contact.

The radial dimension of the protrusion 51 is constant in the area where the notch 53 is not formed, but the radial dimension of the protrusion 51 is smaller in the area where the notch 53 is formed than in the area where the notch 53 is formed. Then, in order to position the notch 53 in a direction where contact with the first bracket 100 is a concern, the inner tube 4 is fixed in a state where it is positioned circumferentially relative to the second bracket 200.

Specifically, as shown in Figures 4 and 5, the inner peripheral surface 40 of the inner tube 4 is formed with an elliptical cross section (long hole). Although not shown, the shaft member 300 (see Figure 4) is also formed with an elliptical cross section corresponding to the inner peripheral surface 40 of the inner tube 4, and the shaft member 300 is fixed by welding or the like to a portion on one side (upper side in Figure 4) or the other side (lower side in Figure 4) of the second bracket 200 in the axial O direction. Therefore, by fastening the inner tube 4 to the second bracket 200 with the shaft member 300 inserted into the inner peripheral surface 40 of the inner tube 4, the inner tube 4 can be positioned in the circumferential direction relative to the second bracket 200.

Meanwhile, the stopper rubber 5 is positioned in the circumferential direction relative to the inner tube 4 by the engagement between the protrusion 32 and the groove 52, and the engagement between the convex portion 33 and the concave portion 54 (see FIG. 6). As a result, the cutout portion 53 is always positioned in a direction where contact with other surrounding parts such as the first bracket 100 is likely (see FIG. 4), thereby suppressing the generation of abnormal noise due to such contact.

In addition, since the protrusion 32 protrudes in the long axis direction (left and right direction in FIG. 5(a)) of the elliptical inner peripheral surface 40 of the inner tube 4, when inserting the shaft member 300 (see FIG. 4) into the inner peripheral side of the inner tube 4, the orientation of the elliptical inner peripheral surface 40 can be easily recognized by the protrusion 32. Therefore, the orientation of the inner tube 4 (the posture in which it should be attached) when fixing the inner tube 4 to the second bracket 200 can be easily grasped, improving the workability of assembling the inner tube 4 to the second bracket 200.

Here, if the plane including the convex portion 33 and perpendicular to the axis O is defined as the imaginary plane V1 (see FIG. 5(b)), the protrusion 32 extends inward in the axial O direction from the position overlapping with the imaginary plane V1, and is formed relatively long to the position where it is connected to the connecting portion 30 (see FIG. 4) of the vibration-proof base 3. Similarly, the tube portion 50 (groove 52) of the stopper rubber 5 also extends from the outer end of the membrane portion 31 in the axial O direction to the vicinity of the connecting portion 30 when the stopper rubber 5 is attached. This ensures that the fitting length between the protrusion 32 and the groove 52 is long in the axial O direction, so that the resistance due to friction between the protrusion 32 and the groove 52 can be increased. Therefore, the holding force of the stopper rubber 5 due to the fitting between the protrusion 32 and the groove 52 can be ensured, so that the stopper rubber 5 can be prevented from falling off.

Furthermore, since the groove 52 is formed up to a position overlapping with the imaginary plane V1 (see FIG. 6) including the recess 54, when the stopper rubber 5 is viewed from the outside in the axial O direction (the side where the recess 54 is formed), that is, when the stopper rubber 5 is viewed from an oblique direction as shown in FIG. 1, the formation position of the groove 52 can be easily grasped. This improves the workability of fitting the protrusion 32 into the groove 52.

On the other hand, if the groove 52 is formed at a position overlapping with the imaginary plane V1 including the recess 54, the amount of rubber in the area where the recess 54 is formed (the position where the recess 54 is formed in the axial O direction) is reduced, making it easier for the protrusion 33 to come out of the recess 54. This is because the stopper rubber 5 is more likely to deform in areas with less rubber. This deformation occurs when, for example, the inner tube 4 (stopper rubber 5) is displaced in the axial O direction from the state shown in FIG. 4, the protrusion 51 is pressed against the outer tube 2, and a force is applied that causes the stopper rubber 5 to come out.

In contrast, in this embodiment, as shown in FIG. 6, the tubular portion 50 of the stopper rubber 5 is formed with a blocking portion 55 that blocks the outer end of the groove 52 in the axial O direction, so that the amount of rubber at the outer end of the tubular portion 50 in the axial O direction can be secured by the blocking portion 55. This makes it possible to suppress the above-mentioned deformation of the tubular portion 50 at the outer portion of the tubular portion 50 in the axial O direction, i.e., at the axial O direction position where the recess 54 is formed. In other words, even if the groove 52 is formed at a position that overlaps with the imaginary plane V1 including the recess 54, it is possible to suppress the protrusion 33 from coming out of the recess 54. Therefore, it is possible to suppress the detachment of the stopper rubber 5 (displacement in the axial O direction of the tubular portion 50 when the vibration isolator 1 is assembled) and the positional deviation in the circumferential direction. Furthermore, by blocking the outer end of the groove 52 in the axial O direction with the blocking portion 55, it is possible to suppress the stopper rubber 5 from being attached to the inner tube 4 upside down (in the wrong orientation).

In this way, areas of the stopper rubber 5 with a small amount of rubber are areas where deformation is likely to occur. Therefore, as shown in FIG. 6(a), the area R1 where the notch 53 is formed and the area R2 where the groove 52 is formed are areas where the stopper rubber 5 is relatively likely to deform.

When viewed in the axial O direction, region R1 is the region between two imaginary lines V2 connecting both circumferential ends of cutout portion 53 (inflection points where the radial dimension of protrusion portion 51 begins to decrease) and axis O, and is the region in which cutout portion 53 exists. When viewed in the axial O direction, region R2 is the region between two imaginary lines V3 connecting both circumferential ends of groove 52 on the inner surface of tube portion 50 and axis O, and is the region in which groove 52 exists.

In this embodiment, the notch 53 is formed on the opposite side of the axis O from the groove 52, so that the regions R1 and R2 do not overlap in the circumferential direction, and the recess 54 is formed in a position that avoids the regions R1 and R2. That is, the groove 52, the notch 53, and the recess 54 are each formed in a different position in the circumferential direction, so that the recess 54 can be disposed in an area with a relatively large amount of rubber. This makes it possible to prevent deformation of the stopper rubber 5 near the area where the recess 54 is formed, so that even if the groove 52 and the notch 53 are formed in the stopper rubber 5, it is possible to prevent the protrusion 33 from coming out of the recess 54.

The protrusions 32 and the convex portions 33 (see FIG. 5) are formed on the membrane portions 31 that cover both sides of the inner tube 4 in the axial O direction, but in this embodiment, the stopper rubbers 5 of the same shape are configured to be attached to both sides of the inner tube 4 in the axial O direction.

Specifically, as shown in FIG. 5, the protrusion 32 is formed at a position shifted by 90° from the convex portion 33 in the circumferential direction. If a plane passing through the center of the inner cylinder 4 in the axial O direction and perpendicular to the axis O is defined as a virtual plane V4 (see FIG. 5(b)), the protrusion 32 and the convex portion 33 located at one end side in the axial O direction of the inner cylinder 4 (upper side in FIG. 5(b)) and the protrusion 32 and the convex portion 33 located at the other end side (lower side in FIG. 5(b)) are formed at positions that are plane-symmetrical with respect to the virtual plane V4.

As shown in FIG. 6, a pair of recesses 54 are formed in the stopper rubber 5, and these pair of recesses 54 face each other (across the axis O) at a position shifted 90° from the groove 52. In other words, the groove 52 and the recesses 54 are formed in positions that allow stopper rubbers 5 of the same shape to be attached to both ends of the inner tube 4 (membrane portion 31) in the axial O direction, so that the stopper rubbers 5 attached to both sides of the inner tube 4 in the axial O direction can be molded using a common mold. Furthermore, because only one type of stopper rubber 5 is attached to the inner tube 4, incorrect attachment of the stopper rubber 5 can be prevented.

The present invention has been described above based on the above embodiment, but the present invention is in no way limited to the above embodiment, and it can be easily imagined that various modifications and improvements are possible within the scope of the present invention.

In the above embodiment, the protrusion 32 and groove 52 are formed at one location in the circumferential direction, but this is not necessarily limited to this. For example, the protrusion 32 and groove 52 may be omitted, or the protrusion 32 and groove 52 may be formed at multiple locations in the circumferential direction. Note that when the protrusion 32 and groove 52 are omitted, the tubular portion 50 located below the overhang 51 may be omitted.

In the above embodiment, the protrusion 32 extends inward in the axial O direction from a position overlapping with the imaginary plane V1, but this is not necessarily limited to this. For example, the outer end of the protrusion 32 in the axial O direction may be positioned inward in the axial O direction from the imaginary plane V1.

In the above embodiment, the inner peripheral surface 40 of the inner tube 4 is formed in an ellipse, and the protruding portion 32 protrudes along the major axis direction of the ellipse. However, this is not necessarily limited to this. For example, the protruding portion 32 may protrude in the minor axis direction of the ellipse, or the protruding portion 32 may protrude in a direction different from the major and minor axis directions.

In the above embodiment, a case has been described in which the curved surface 33c (the top of the convex portion 33) is not in contact with the inner surface 54c of the concave portion 54 when the stopper rubber 5 is attached, but this is not necessarily limited to this. For example, a configuration in which the curved surface 33c (the top of the convex portion 33) is in contact with (bites into) the inner surface 54c of the concave portion 54 when the stopper rubber 5 is attached may also be used.

In the above embodiment, the apex of the convex portion 33 is a curved surface 33c, but this is not necessarily limited to this. For example, the apex of the convex portion 33 (the connection portion of the first inclined surface 33a and the second inclined surface 33b) may be a flat surface extending in the axial O direction, or multiple projections and recesses may be formed from the first inclined surface 33a to the second inclined surface 33b.

In the above embodiment, the first inclined surface 33a is a curved surface that is concave toward the inner tube 4, and the inner surface 54a of the recess 54 is a curved surface that follows the first inclined surface 33a, but this is not necessarily limited to this. For example, the first inclined surface 33a and the inner surface 54a of the recess 54 may be flat surfaces that are inclined with respect to the axis O, or the inner surface 54a of the recess 54 may be a flat surface that extends in the radial direction.

In the above embodiment, the protrusion 33 is formed at one location on a portion of the membrane portion 31 in the circumferential direction, but this is not necessarily limited to this. For example, the protrusion 33 may be formed at multiple locations on the membrane portion 31 in the circumferential direction, or the protrusion 33 may be formed continuously around the entire circumference of the membrane portion 31 in the circumferential direction. In either case, a recess 54 (with a shape corresponding to the protrusion 33) may be formed in the stopper rubber 5 at a position where the protrusion 33 can be fitted.

In the above embodiment, a case has been described in which both circumferential ends of the convex portion 33 contact the inner surface 54b of the concave portion 54 when the stopper rubber 5 is attached, i.e., the circumferential dimensions of the convex portion 33 and the concave portion 54 are approximately the same, but this is not necessarily limited to this. For example, a configuration in which both circumferential ends of the convex portion 33 do not contact the inner surface 54b of the concave portion 54 when the stopper rubber 5 is attached, i.e., a configuration in which the circumferential dimension of the concave portion 54 is larger than that of the convex portion 33, may also be used. A configuration in which the circumferential dimension of the concave portion 54 is slightly smaller than that of the convex portion 33 may also be used.

In the above embodiment, the second inclined surface 33b is a flat surface, but this is not necessarily limited to this. For example, the second inclined surface 33b may be formed as a curved surface that is convex toward the inner tube 4 side or the opposite side. When the second inclined surface 33b is a curved surface, the "inclination (degree of inclination) relative to the axis O direction" refers to the inclination, relative to the axis O, of a straight line connecting the connection position (inflection point) of the outer peripheral surface of the membrane portion 31 and the second inclined surface 33b and the connection position (inflection point) of the second inclined surface 33b and the curved surface 33c in a cross-sectional view cut along a plane including the axis O.

In the above embodiment, a case has been described in which the membrane portion 31 (the rubber membrane on which the protrusions 32 and the convex portions 33 are formed) is vulcanized and molded integrally with the connecting portion 30 of the vibration-proof base 3, but this is not necessarily limited to this. For example, the membrane portion 31 and the connecting portion 30 may be separate.

In the above embodiment, a case where the notch 53 is formed in the protrusion 51 has been described, but this is not necessarily limited to this. For example, the notch 53 may be omitted, and the radial dimension of the protrusion 51 may be constant over the entire circumference, or the radial dimension of the protrusion 51 may change stepwise or continuously in the circumferential direction. In other words, the shape of the protrusion 51 is not limited to the above form.

In the above embodiment, the inner circumferential surface 40 of the inner tube 4 is formed in an elliptical shape in order to orient the cutout portion 53 in a specific direction (determine the assembly direction of the inner tube 4), but this is not necessarily limited to this. For example, if there is no need to determine the assembly direction of the inner tube 4, the inner circumferential surface 40 of the inner tube 4 may be formed in a circular shape.

In the above embodiment, the formation regions R1, R2 of the groove 52 and the notch 53 do not overlap in the circumferential direction, and the recess 54 is formed at a position that avoids the regions R1, R2. However, this is not necessarily limited to this. For example, the regions R1, R2 may overlap in the circumferential direction, or the recess 54 may be formed within the regions R1, R2.

When forming the recess 54 in regions R1 and R2, it is preferable to form the recess 54 in the formation region R1 of the notch 53. This is because the region R1 where the notch 53 is formed is a region where the protrusion 51 does not come into contact with the outer tube 2 when the inner tube 4 is displaced in the axial O direction (a region where a force that causes the protrusion 33 to come out of the recess 54 is unlikely to be applied). Therefore, by forming the recess 54 (protrusion 33) in such region R1, it is possible to prevent the protrusion 33 from coming out of the recess 54.

In the above embodiment, the protrusion 32 and the convex portion 33 located at one end of the inner tube 4 in the axial O direction and the protrusion 32 and the convex portion 33 located at the other end are formed at positions that are plane-symmetrical with respect to the imaginary plane V4, and the groove 52 and the recess 54 are formed at positions where the stopper rubber 5 of the same shape can be attached to both ends of the inner tube 4 in the axial O direction, but this is not necessarily limited to the above.

For example, a point located on the axis O at the center of the inner tube 4 in the axial O direction may be set as a point of symmetry, and the protrusions 32 and convex portions 33 located at one end of the inner tube 4 in the axial O direction and the protrusions 32 and convex portions 33 located at the other end may be formed at positions that are point symmetrical. Also, the protrusions 32 and convex portions 33 may be formed at positions that are not symmetrical between one end and the other end of the inner tube 4 in the axial O direction, or the protrusions 32 and convex portions 33 may be formed only at one end in the axial O direction. Also, a configuration in which stopper rubbers 5 of different shapes are attached to one end and the other end of the inner tube 4 in the axial O direction may be used.

In the above embodiment, the outer end of the groove 52 in the axial O direction is blocked by the blocking portion 55, but this is not necessarily limited to this. For example, the blocking portion 55 may be omitted, and the outer end of the groove 52 in the axial O direction may be left open.

In the above embodiment, a configuration in which the protruding portion 51 protrudes from the outer peripheral surface of the tubular portion 50 of the stopper rubber 5, i.e., a case in which the axial O dimension of the tubular portion 50 is greater than the protruding portion 51, has been described, but this is not necessarily limited to this. For example, a configuration in which the axial O dimension of the stopper rubber 5 is approximately constant in the radial direction (the stopper rubber 5 is formed in a disk shape) may also be used.

In the above embodiment, the recess 54 is formed on the inner circumferential surface of the tubular portion 50 by cutting out the end face 50b on the outer side in the axial O direction, but this is not necessarily limited to this. For example, the recess 54 may be formed on the inner circumferential surface of the tubular portion 50 that is more inward in the axial O direction than the end face 50b on the outer side in the axial O direction.

In the above embodiment, a detailed description of the configuration in which the inner tube 4 having an elliptical inner peripheral surface 40 is fastened to the second bracket 200 by the shaft member 300 has been omitted, but an example of such a configuration will be described below. For example, when the shaft member 300 is a bolt, the shaft portion on the head side of the bolt is formed in an elliptical shape (corresponding to the shape of the inner peripheral surface 40) without a male thread, while the shaft portion on the tip side of the bolt is formed with a male thread. The head side of this shaft member 300 is fixed to one side of the second bracket 200 in the axial O direction (upper side in Figure 4) by welding or the like, and the inner tube 4 is fitted into the fixed shaft member 300. Then, the tip side of the shaft member 300 is inserted into the through hole on the other side of the second bracket 200 in the axial O direction (lower side in Figure 4) and a nut is fastened. As a result, the inner tube 4 can be fixed to the second bracket 200 in a state where it is positioned in the circumferential direction.

1 Vibration isolation device 2 Outer cylinder 3 Vibration isolation base 31 Film portion (rubber film)
32 Protruding portion 33 Convex portion 33a First inclined surface 33b Second inclined surface 4 Inner cylinder 40 Inner peripheral surface 5 Stopper rubber 50 Cylinder portion 51 Protruding portion 52 Groove 53 Cutout portion 54 Recesses 54a to 54c Inner surface of recess 55 Closing portion 100 First bracket (first member)
200 Second bracket (second member)
O axis V1 virtual plane

Claims (11)

A cylindrical outer cylinder fixed to a first member constituting one of the support side and the vibration source side;
a vibration-isolating base made of a rubber-like elastic material connected to an inner peripheral surface of the outer cylinder;
an inner cylinder having a cylindrical shape and disposed on an inner peripheral side of the outer cylinder by connecting the vibration-isolating base to an outer peripheral surface thereof, the inner cylinder being fixed to a second member constituting the other of the support body side or the vibration source side;
a rubber film made of a rubber-like elastic material covering an outer peripheral surface of the inner cylinder at an axial end portion thereof;
a ring-shaped stopper rubber attached to an outer circumferential surface of the rubber film to absorb impact when the first member or the outer cylinder collides with the second member,
the stopper rubber has a recess that is recessed at an axially outer end of an inner circumferential surface of the stopper rubber,
the rubber film includes a protrusion that protrudes from an outer circumferential surface of the rubber film toward the recess and is fitted into the recess,
The protrusion includes a first inclined surface that decreases in diameter from a top of the protrusion toward an inner side in the axial direction, and a second inclined surface that decreases in diameter from the top of the protrusion toward an outer side in the axial direction,
13. An anti-vibration device, comprising: a first inclined surface having a larger inclination with respect to an axial direction than a second inclined surface having a larger inclination with respect to the axial direction. The vibration isolation device according to claim 1, characterized in that, when the stopper rubber is attached with the protrusion fitted into the recess, the top of the protrusion is not in contact with the inner surface of the recess. the first inclined surface is a curved surface that is concave toward the inner tube side in a cross-sectional view taken along a plane including an axis,
3. The vibration isolation device according to claim 1, wherein an inner surface of the recess that contacts the first inclined surface is a curved surface that conforms to the first inclined surface. The protrusion is formed at one location in a circumferential direction of the rubber film, or at a plurality of locations in the circumferential direction of the rubber film,
4. The vibration isolation device according to claim 1, wherein an inner surface of the recess facing in a circumferential direction is in contact with the protrusion. The vibration isolation device according to claim 4, characterized in that the convex portion is formed at one location on a portion of the rubber film in the circumferential direction. the stopper rubber includes a cylindrical tube portion attached to an outer circumferential surface of the rubber film and having the recessed portion formed on an inner circumferential surface thereof, and a protruding portion protruding radially from the outer circumferential surface of the tube portion to absorb impact when the first member or the outer tube collides with the second member,
The cylindrical portion includes a groove extending axially outward from an axially inner end of an inner circumferential surface of the cylindrical portion,
6. The vibration-damping device according to claim 1, wherein the rubber film includes a protrusion that protrudes radially outward from an outer circumferential surface of the rubber film and is fitted into the groove. The vibration isolation device according to claim 6, characterized in that the protrusion extends from a position that overlaps with a virtual plane that includes the convex portion and is perpendicular to the axis, toward the axial center of the inner cylinder. The vibration isolation device according to claim 7, characterized in that the cylindrical portion has a closing portion that closes the axially outer end of the groove. The protruding portion includes a cutout portion that is formed so that a radial dimension of the protruding portion is smaller than other portions,
The inner peripheral surface of the inner tube is formed into an elliptical shape for fixing the inner tube to the second member with the notch portion facing a predetermined direction,
9. The vibration isolation device according to claim 6, wherein the recess, the groove, and the notch are each formed at different positions in the circumferential direction. the convex portion and the protruding portion are formed on a rubber film covering an outer circumferential surface of one axial end side of the inner cylinder and a rubber film covering an outer circumferential surface of the other axial end side of the inner cylinder,
10. The vibration isolation device according to claim 9, wherein the recess and the groove are formed at positions where the stopper rubbers having the same shape can be attached to both axial ends of the inner cylinder. An anti-vibration device according to claim 9 or 10, characterized in that the protrusion protrudes along the long axis direction of the elliptical inner peripheral surface of the inner cylinder.

Images