JP2025003192A - Suspended type fluid-filled vibration isolation device - Google Patents

Abstract

To provide a new fluid sealed type vibration control device which enables an outer cylinder metal fitting having an abnormal shape in an axial view to be fitted into a bracket member stably.SOLUTION: In a hanging fluid sealed type vibration control device 10, an outer cylinder metal fitting 20 has a straight part 34 and a taper part 36. The outer cylinder metal fitting 20 is provided with a caulking piece 40 fixedly caulked to a caulking part 50. A thickness dimension of the caulking piece 40 is larger than that of the caulking part 50. The straight part 34 is formed in a long cylindrical shape having a pair of two-face width parts 42 and a pair of curved parts 44. The hanging fluid sealed type vibration control device 10 is further provided with a bracket member 76 into which the straight part 34 is fitted. The bracket member 76 is spaced apart from the caulking piece 40 in a downward direction and spaced apart from the taper part 36. A press-in margin in the two-face width part 42 is larger than that in the curved part 44. A circumferential length dimension C of the two-face width part 42 is larger than or equal to one-fourth times of a long diameter dimension L of the straight part 34.SELECTED DRAWING: Figure 3

Description

The present invention relates to a fluid-filled vibration-damping device used, for example, in engine mounts of automobiles, and in particular to a so-called suspended type fluid-filled vibration-damping device.

Conventionally, anti-vibration devices used in engine mounts of automobiles and the like have a structure in which an inner member and a cylindrical outer member are elastically connected by a main rubber elastic body. Another type of anti-vibration device known is a fluid-filled anti-vibration device that utilizes the vibration-proofing effect exerted based on the flow action of a non-compressible fluid sealed inside. Among such fluid-filled anti-vibration devices, those in which the inner member is located lower than the outer member are called suspended type (inverted type), and are proposed, for example, in JP 2019-207022 A (Patent Document 1).

JP 2019-207022 A

However, in recent years, there has been a demand for smaller vehicles, and it may not be possible to secure sufficient installation space for the fluid-filled vibration isolation device. In such cases, it may be possible to give the outer member a shape other than the typical perfect circle shape in a plan view (axial view) to fit the installation space, but this could make it difficult to press the outer member into the bracket.

The present invention was made against the background of the above-mentioned circumstances, and the problem to be solved is to provide a new suspended type fluid-filled vibration-damping device that can stably press-fit an outer tubular metal fitting having a different shape when viewed in the axial direction into a bracket member.

First, the inventors considered making the outer tubular metal fitting roughly rectangular when viewed in the axial direction to accommodate the required installation space. However, in conventional fluid-filled vibration-damping devices, simply making the outer tubular metal fitting roughly rectangular when viewed in the axial direction was not enough to ensure sufficient rigidity in each wall, making it difficult to press-fit into the bracket member. After extensive research, the inventors discovered a structure that would allow an irregularly shaped outer tubular metal fitting to be stably pressed into the bracket member, leading to the invention.

The following describes preferred embodiments for understanding the present invention. However, each embodiment described below is merely an example, and may be combined with one another as appropriate. The multiple components described in each embodiment may be recognized and used independently as far as possible, and may also be combined with any of the components described in another embodiment as appropriate. As a result, the present invention is not limited to the embodiments described below, and various alternative embodiments may be realized.

In the first embodiment, an inner shaft member is inserted into the lower opening of an outer tubular metal fitting, and the inner shaft member and the outer tubular metal fitting are connected by a main rubber elastic body, and a pressure-receiving chamber whose wall is partly made of the main rubber elastic body and an equilibrium chamber whose wall is partly made of a flexible membrane are formed inside, and in the suspended type fluid-filled vibration-proof device in which a non-compressible fluid is filled in the pressure-receiving chamber and the equilibrium chamber, the upper part of the outer tubular metal fitting is a straight part extending with a constant cross section, and the lower part is a tapered part whose diameter decreases downward, and the upper end of the outer tubular metal fitting is provided with a crimping piece that is press-crimped and fixed to the crimping part of the fixing member fixed to the flexible membrane, and the thickness dimension of the crimping piece is made larger than the thickness dimension of the crimping part. The straight portion of the outer tubular metal fitting is an elongated cylindrical shape having a pair of linear two-face width portions when viewed in the axial direction and a pair of curved portions that connect the pair of two-face width portions in the circumferential direction, a bracket member is provided into which the straight portion of the outer tubular metal fitting is press-fitted, the bracket member is spaced downward from the crimping piece of the outer tubular metal fitting, and the bracket member is spaced from the tapered portion of the outer tubular metal fitting, the press-fit allowance of the straight portion in the two-face width portion into the bracket member is larger than the press-fit allowance of the straight portion in the curved portion into the bracket member, and the circumferential length dimension of the two-face width portion is 1/4 or more times the major axis dimension of the straight portion.

According to this aspect, the straight portion at the upper part of the outer tubular metal fitting is formed into an elongated cylindrical shape having a pair of linear two-sided width portions and a pair of curved portions that connect the pair of two-sided width portions to each other in the circumferential direction. A bracket member is provided to press-fit the straight portion, and the press-fit allowance of the straight portion in the two-sided width portion into the bracket member is made larger than the press-fit allowance of the straight portion in the curved portion into the bracket member, so that a larger press-fit fixing force can be obtained in the two-sided width portion than in the curved portion. Here, when the two-sided width portions are connected by a wall portion that simply extends linearly (when the outer tubular metal fitting is made substantially rectangular in the axial view), there is a risk that sufficient rigidity is not obtained and deformation occurs during press-fitting. However, by adopting a structure in which the two-sided width portions are connected by a curved wall portion (curved portion), it is possible to improve the rigidity of not only the wall portion (curved portion) that connects the two-sided width portions, but also the two-sided width portion itself that continues from the curved portion. In addition, the thickness dimension of the crimping piece at the upper end of the outer tubular metal fitting is made larger than the thickness dimension of the crimping portion in the fixing member. This not only improves the strength of the crimping piece, enabling the fixing member to be stably crimped and fixed to the outer tubular fitting, but also achieves a further improvement in the rigidity of the straight portion of the outer tubular fitting that continues from the crimping piece. In particular, the circumferential length dimension of the two-face width portion is at least 1/4 the major axis dimension of the straight portion. This ensures a large area for the two-face width portion, further improving rigidity. As a result, even when the outer tubular fitting is oval in shape when viewed in the axial direction as described above, it is possible to effectively improve the rigidity of the two-face width portion, stably press-fit the outer tubular fitting into the bracket member, and stably obtain resistance to the outer tubular fitting coming out of the bracket member.

In addition, the bracket member is spaced apart from the tapered portion of the outer tubular fitting, and the bracket member does not abut against the outer tubular fitting in the axial direction. This allows the outer tubular fitting and the bracket member to be positioned with high axial accuracy, and prevents the outer tubular fitting and the bracket member from hitting each other and generating abnormal noise due to component variations, etc.

In the second aspect, in the suspended type fluid-filled vibration-proof device according to the first aspect, the upper part of the bracket member is a press-fit tubular part into which the straight part of the outer tubular metal fitting is press-fitted, and the lower part of the bracket member is a tapered reduced diameter part that becomes smaller in diameter toward the bottom, and the reduced diameter part of the bracket member is inserted onto the tapered part of the outer tubular metal fitting and is spaced axially downward from the tapered part.

According to this aspect, by providing a tapered reduced diameter portion in the bracket member, the rigidity of the bracket member as well as the outer tubular metal fitting can be improved. In addition, by covering the tapered portion of the outer tubular metal fitting with the reduced diameter portion of the bracket member, the tapered portion can be protected by the reduced diameter portion. Furthermore, by separating the reduced diameter portion of the bracket member downward from the tapered portion of the outer tubular metal fitting, the relative position in the axial direction between the outer tubular metal fitting and the bracket member can be set with high precision. And by providing a reduced diameter portion at the bottom of the bracket member, the space required for arranging the bracket member can be made smaller, making it possible to meet stricter space requirements, and for example, making it possible to arrange other members around the reduced diameter portion.

The third aspect is a suspended type fluid-filled vibration isolation device according to the first or second aspect, in which the vertical width dimension of the two-face width portion is at least half the circumferential length dimension of the two-face width portion.

According to this aspect, by setting the vertical width dimension of each two-face width portion within the above range, the area of each two-face width portion is secured, and a sufficiently large press-fit fixing force can be obtained. In addition, although there is no upper limit on the vertical width dimension of the two-face width portion, for example, by setting it to no more than three times the circumferential length dimension of the two-face width portion, the axial length of the straight portion of the outer cylindrical metal fitting can be prevented from becoming excessively long, making it possible to compact the fluid-filled vibration damping device in the vertical direction and also making it easier to avoid a decrease in overall rigidity due to an increase in length.

The present invention provides a suspended, fluid-filled vibration-damping device that can stably press-fit an outer tubular metal fitting having an irregular shape, such as an oval shape when viewed in the axial direction, into a bracket member.

FIG. 1 is a plan view of a fluid-filled vibration isolation device according to an embodiment of the present invention; FIG. 2 is a right side view of the fluid-filled type vibration isolation device shown in FIG. 3 is a cross-sectional view taken along line III-III in FIG. IV-IV cross-sectional view in FIG. FIG. 2 is a plan view showing a vibration isolator body in the fluid-filled type vibration isolator shown in FIG. VI-VI cross-sectional view in FIG. 5. Cross-sectional view taken along the line VII-VII in FIG.

In order to clarify the present invention more specifically, the following embodiment of the present invention will be described in detail with reference to the drawings.

First, Figures 1 to 4 show an engine mount 10 for an automobile as one embodiment of a suspended type fluid-filled vibration isolation device constructed according to the present invention. The engine mount 10 comprises a mount body 12 shown in Figures 5 to 7, and an inner bracket 14 and an outer bracket 16 fixed to the mount body 12. For example, the inner bracket 14 is fixed to a power unit (not shown), and the outer bracket 16 is fixed to a vehicle body (not shown), thereby mounting the engine mount 10 to the vehicle. In the following description, the vertical direction generally refers to the vertical direction in Figure 3. Also, the axial direction generally refers to the vertical direction in Figure 3, which is the central axial direction of the mount body 12.

More specifically, the mount body 12 comprises an inner shaft member 18 and an outer tubular metal fitting 20, the inner shaft member 18 being inserted into the lower opening of the outer tubular metal fitting 20, and the inner shaft member 18 and the outer tubular metal fitting 20 being connected by a main rubber elastic body 22. The mount body 12 also has formed therein a pressure-receiving chamber 24, part of whose wall is constituted by the main rubber elastic body 22, and an equilibrium chamber 28, part of whose wall is constituted by a flexible membrane 26, and the pressure-receiving chamber 24 and the equilibrium chamber 28 are filled with a non-compressible fluid.

The inner shaft member 18 is a generally circular or oval block shape extending vertically in the axial direction, and is a highly rigid member formed from metal, hard synthetic resin, or the like. A bolt hole 30 is formed on the lower surface of the inner shaft member 18, opening downward and extending vertically, and a bolt 74 (described later) is fastened to the bolt hole 30. In this embodiment, the outer diameter dimensions of the lower and upper parts of the inner shaft member 18 are different, and the outer diameter dimension of the lower part of the inner shaft member 18 is approximately constant, while the outer diameter dimension of the upper part of the inner shaft member 18 gradually increases upward. In other words, the outer peripheral surface of the upper part of the inner shaft member 18 is a tapered surface 32 whose outer diameter dimension gradually increases upward. The above-mentioned bolt hole 30 is formed in the lower part of the inner shaft member 18.

The outer tubular metal fitting 20 is a cylindrical member extending in the vertical direction as a whole, and is made of metal. The upper part of the outer tubular metal fitting 20 is a straight part 34 that extends in the vertical direction with a substantially constant cross section, and the lower part is a tapered part 36 that becomes smaller in diameter toward the bottom. That is, a bent part 38 is provided in the axial middle part of the outer tubular metal fitting 20, and the upper part of the bent part 38 is the straight part 34, and the lower part of the bent part 38 is the tapered part 36. The upper end part of the outer tubular metal fitting 20 is provided with a step part 39 that spreads out in an annular shape on the outer periphery side. A cylindrical part that protrudes upward is provided at the outer periphery end of this step part 39, and the cylindrical part (the upper end part of the outer tubular metal fitting 20) forms a crimping piece 40 that is press-crimped and fixed to the crimping part 50 of the fixing member 48 described later that is fixed to the flexible film 26. The crimping piece 40 is provided continuously around the entire circumference in the circumferential direction.

As shown in the plan view of the mount body 12 in Figure 5, the straight portion 34 of the outer tubular metal fitting 20 has an elongated cylindrical shape having a pair of two-sided width portions 42, 42 that are linear in the axial direction (plan view) and a pair of curved portions 44, 44 that circumferentially connect the pair of two-sided width portions 42, 42. That is, the outer tubular metal fitting 20 has a long diameter dimension L, which is the left-right dimension in Figure 6, and a short diameter dimension S, which is the left-right dimension in Figure 7, in the axial direction (plan view), and the circumferential length dimension C (see Figure 5) of each two-sided width portion 42 is 1/4 or more times the long diameter dimension L of the straight portion 34 ((L/4) ≦ C).

The vertical width dimension H (see FIG. 7) of each two-face width portion 42 is not limited, but is preferably, for example, 1/2 or more times the circumferential length dimension C of each two-face width portion 42 ((C/2)≦H). This ensures that the area of each two-face width portion 42 is sufficiently large, allowing the outer tubular fitting 20 to be stably press-fitted into the bracket member 76 as described below, and also ensuring a pull-out force (resistance to pull-out). Furthermore, it is preferable that the vertical dimension of each two-face width portion 42 is, for example, 3 times or less the circumferential length dimension C of each two-face width portion 42. This prevents the bracket member 76 from becoming excessively large in the vertical direction.

The inner shaft member 18 is arranged on the inner periphery of the outer tubular metal fitting 20 with their central axes aligned, and the inner shaft member 18 and the outer tubular metal fitting 20 are elastically connected by the main rubber elastic body 22. In this embodiment, the lower end of the inner shaft member 18 is located lower than the lower end of the outer tubular metal fitting 20. The main rubber elastic body 22 has an approximately elongated cylindrical shape as a whole, and the inner periphery of the main rubber elastic body 22 is fixed to the outer periphery of the upper part of the inner shaft member 18 (tapered surface 32), and the outer periphery of the main rubber elastic body 22 is fixed to the inner periphery of the tapered portion 36 of the outer tubular metal fitting 20. The upper part of the inner shaft member 18 is located above the tapered portion 36 of the outer tubular metal fitting 20, so that the main rubber elastic body 22 has a tapered cylindrical shape with the inner periphery located higher than the outer periphery. In this embodiment, the main rubber elastic body 22 is formed as an integrally vulcanized molded product that includes the inner shaft member 18 and the outer tubular metal fitting 20.

In addition, in the outer tubular metal fitting 20, a seal rubber layer 46 is provided on the inner peripheral surface of the straight portion 34, and the seal rubber layer 46 has a substantially constant thickness and is fixed over substantially the entire length of the straight portion 34 in the vertical direction. In this embodiment, the seal rubber layer 46 is formed integrally with the main rubber elastic body 22.

A flexible membrane 26 is attached to the integrally vulcanized molded product of the main rubber elastic body 22. The flexible membrane 26 is a thin rubber membrane having a generally disk or circular dome shape, and is easily deformable with sufficient slack in the axial direction. A fixing member 48 is fixed to the outer peripheral end of the flexible membrane 26. The fixing member 48 is generally cylindrical and extends in the axial direction as a whole, and is made of a hard material such as metal or synthetic resin. As a result, one opening of the fixing member 48 (the upper opening in FIG. 3) is blocked by the flexible membrane 26, and the other opening of the fixing member 48 is formed with a generally annular crimping portion 50 that protrudes toward the outer periphery.

The crimped portion 50 of the fixing member 48 is overlapped with the outer peripheral portion of the bottom plate member 58 of the partition member 54 as described below, and is press-crimped and fixed over the entire circumference by the crimped piece 40 provided at the upper end of the outer tubular metal fitting 20. As a result, the flexible film 26 is arranged facing the main rubber elastic body 22 at a distance upward, and the upper opening of the outer tubular metal fitting 20 is covered by the flexible film 26. In this embodiment, one end side of the fixing member 48 (the upper part in FIG. 3) is covered on the inner and outer surfaces by the rubber constituting the flexible film 26, and the crimped portion 50 at the other end of the fixing member 48 is exposed from the rubber constituting the flexible film. In particular, in this embodiment, the thickness dimension of the crimped piece 40 at the upper end of the outer tubular metal fitting 20 is made larger than the thickness dimension of the crimped portion 50 of the fixing member 48.

By attaching the flexible membrane 26 in this manner, a fluid chamber 52 is formed between the axially opposing surfaces of the main rubber elastic body 22 and the flexible membrane 26, sealed from the outside space and filled with a non-compressible fluid. The non-compressible fluid filled in the fluid chamber 52 is not limited, but water, alkylene glycol, polyalkylene glycol, silicone oil, or a mixture thereof is preferably used. In order to efficiently obtain the vibration-damping effect based on the flow action of the fluid described below, a low-viscosity fluid of 0.1 Pa·s or less is desirable.

In addition, a partition member 54 is disposed in the fluid chamber 52. The partition member 54 has a generally circular disk shape overall, and in this embodiment, includes a partition member main body 56 and a bottom plate member 58.

The partition member body 56 is generally disk-shaped and is a hard member made of synthetic resin, metal, or the like. A circumferential groove 60 that opens to the outer periphery is formed on the outer periphery of the partition member body 56.

The bottom plate member 58 is a generally circular plate that is thinner than the partition member body 56, and is a hard member made of synthetic resin, metal, or the like, like the partition member body 56. In this embodiment, the outer diameter of the bottom plate member 58 is larger than the outer diameter of the partition member body 56, and a communication hole 62 is formed on the outer periphery of the bottom plate member 58, penetrating the bottom plate member 58 in the thickness direction and communicating with the peripheral groove 60 of the partition member body 56.

The partition member 54 is accommodated in the fluid chamber 52 and supported by the outer tubular metal fitting 20. That is, the partition member 54 is fixed to the outer tubular metal fitting 20 by crimping the crimping piece 40 at the upper end of the outer tubular metal fitting 20 to the inner circumferential side with the outer peripheral end of the bottom plate member 58 placed on the step portion 39 of the outer tubular metal fitting 20. In particular, in this embodiment, the crimping piece 40 is crimped in a state in which the crimping portion 50 of the fixing member 48 fixed to the flexible film 26 is overlapped from above on the outer peripheral end of the bottom plate member 58, thereby fixing the bottom plate member 58 and the flexible film 26 (crimping portion 50) to the outer tubular metal fitting 20. As a result, the partition member 54 is arranged to spread in the axis-perpendicular direction within the fluid chamber 52.

By disposing the partition member 54 in the fluid chamber 52, the fluid chamber 52 is divided into two, upper and lower, by the partition member 54. As a result, below the partition member 54, a pressure-receiving chamber 24 is formed, the wall of which is partly made up of the main rubber elastic body 22, and in which internal pressure fluctuations are induced when vibration is input. Moreover, above the partition member 54, an equilibrium chamber 28 is formed, the wall of which is partly made up of the flexible membrane 26, and in which volumetric changes due to deformation of the flexible membrane 26 are permitted.

As described above, the partition member 54 and the flexible membrane 26 are fixed to the outer tubular metal fitting 20 in a state where they are stacked vertically, so that the outer peripheral opening of the circumferential groove 60 in the partition member body 56 is covered with the fixing member 48 fixed to the flexible membrane 26. One circumferential end of the circumferential groove 60 is connected to the pressure receiving chamber 24 through a communication hole 62 formed in the bottom plate member 58, and the other circumferential end is connected to the equilibrium chamber 28 through a communication hole 64 formed in the partition member body 56. As a result, an orifice passage 66 that mutually connects the pressure receiving chamber 24 and the equilibrium chamber 28 is formed using the circumferential groove 60. The tuning frequency of the orifice passage 66 is not limited, but can be set to a low frequency of, for example, about 10 Hz, which corresponds to engine shake.

The aforementioned inner bracket 14 and outer bracket 16 are attached to the mount body 12 having such a structure.

The inner bracket 14 is a member that extends in the vertical direction as a whole in FIG. 1, and is a highly rigid member made of metal or the like. The inner bracket 14 has a generally rectangular cross section in the upper part in FIG. 1, and spreads out to both the left and right sides in the lower part in FIG. 1. The inner bracket 14 has a bolt insertion hole 68 that penetrates in the vertical direction in the lower part in FIG. 3, and multiple bolt insertion holes 70 are formed at the lower end in FIG. 1. In addition, a cushioning rubber 72 that protrudes outward is fixed to the outer peripheral surface of the part of the inner bracket 14 that is outside the bolt insertion hole 68 in the lower part in FIG. 3.

The inner bracket 14 is placed on the underside of the inner shaft member 18, and the bolt holes 30 in the inner shaft member 18 and the bolt insertion holes 68 in the inner bracket 14 are aligned with each other. Then, a bolt 74 is inserted into the bolt insertion hole 68 and fastened to the bolt hole 30, thereby fixing the inner bracket 14 to the inner shaft member 18.

The outer bracket 16 is a highly rigid member made of metal, and includes a bracket member 76 into which the straight portion 34 of the outer tubular metal fitting 20 of the mount body 12 is press-fitted. The outer bracket 16 also includes a tubular portion 78 below the bracket member 76, and a pair of extensions 80, 80 that protrude to the sides (both left and right sides in FIG. 1) from the bracket member 76 and the tubular portion 78. A bolt insertion hole 82 is formed at the protruding end of each extension 80. One extension 80 (left in FIG. 1) has an attachment portion 84 that protrudes upward, and a bolt 86 that protrudes upward is fixed to the upper end of the attachment portion 84. The bracket member 76, the tubular portion 78, each extension 80, and the attachment portion 84 are fixed, for example, by welding, and the outer bracket 16 is integrally formed. Note that welding of each part of the outer bracket 16 may be performed, for example, after the mount body 12 is press-fitted into the bracket member 76.

The bracket member 76 has the same shape as the outer tubular metal fitting 20 in the axial view (plan view), and is generally an elongated cylindrical shape. In this embodiment, the upper part of the bracket member 76 is a press-in tubular part 88 into which the straight part 34 of the outer tubular metal fitting 20 is press-in, and the lower part of the bracket member 76 is a tapered reduced diameter part 90 that has a smaller diameter toward the bottom. That is, the press-in tubular part 88 of the bracket member 76 has a pair of straight parts 92, 92 corresponding to the pair of two-face width parts 42, 42 of the outer tubular metal fitting 20 in a plan view, and a pair of arc-shaped parts 94, 94 corresponding to the pair of curved parts 44. The press-in tubular part 88 has a certain vertical dimension with such a substantially oval cross-sectional shape. An inner flange-shaped part 96 that bends to the inner periphery and expands into an annular shape is provided at the lower end of the reduced diameter part 90, and a central hole 98 that penetrates in the vertical direction is formed on the inner periphery side of the inner flange-shaped part 96. When pressed into the bracket member 76 of the mount body 12 described below, the lower end of the inner shaft member 18 protrudes downward through the central hole 98 and is positioned within the cylindrical portion 78 provided below the bracket member 76.

Here, when the mount body 12 is pressed into the bracket member 76, the force generated by the press-fitting is applied more strongly to each two-face width portion 42 than to each curved portion 44 of the outer tubular metal fitting 20. Specifically, in the state of the bracket member 76 (outer bracket 16) alone before the mount body 12 is pressed into the bracket member 76, the distance S' (see FIG. 4) between the opposing surfaces of the pair of linear portions 92, 92 is slightly smaller than the distance between the outer surfaces of the two-face width portions 42 of the outer tubular metal fitting 20 (i.e., the minor axis dimension S of the outer tubular metal fitting 20). In addition, the distance L' (the left-right dimension in FIG. 3) between the opposing surfaces of the pair of arc-shaped portions 94, 94 is equal to or slightly smaller than the distance between the outer surfaces of the curved portions 44 of the outer tubular metal fitting 20 (i.e., the major axis dimension L of the outer tubular metal fitting 20). The press-fit allowance (S-S') of the straight portion 34 in the bracket member 76 at each two-face width portion 42 is set to be greater than the press-fit allowance (L-L') of the straight portion 34 in the bracket member 76 at each curved portion 44.

In this way, when the straight portion 34 of the outer tubular metal fitting 20 of the mount body 12 is press-fitted into the bracket member 76, as shown in Figures 3 and 4, the bracket member 76 is spaced downward from the crimping piece 40 and the step portion 39 of the outer tubular metal fitting 20. The bracket member 76 is also spaced from the tapered portion 36 of the outer tubular metal fitting 20. In this embodiment, since a reduced diameter portion 90 is provided at the lower portion of the bracket member 76, when the straight portion 34 is press-fitted into the bracket member 76, the reduced diameter portion 90 is inserted outside the tapered portion 36 and is spaced downward in the axial direction from the tapered portion 36.

After the mount body 12 is press-fitted into the bracket member 76, the inner bracket 14 is inserted into the cylindrical portion 78 of the outer bracket 16 and the bolts 74 are fastened to form the engine mount 10 of this embodiment. For example, the inner bracket 14 is bolted to a power unit (not shown) and the outer bracket 16 is bolted to a vehicle body (not shown), thereby elastically connecting the power unit and the vehicle body. In this embodiment, the cushioning rubber 72 provided on the outer peripheral surface of the inner bracket 14 is located within the cylindrical portion 78 of the outer bracket 16, and the cushioning rubber 72 comes into contact with the wall portion of the cylindrical portion 78 to form a stopper mechanism that limits the relative displacement between the inner bracket 14 and the outer bracket 16.

According to the engine mount 10 of the present embodiment, which is constructed as described above, the straight portion 34 is provided at the upper portion of the outer tubular metal fitting 20, and the crimping piece 40 is provided continuously from the straight portion 34 through the step portion 39 at the upper end of the outer tubular metal fitting 20. The crimping piece 40 is provided in an annular shape over the entire circumference in the circumferential direction, and the crimping piece 40 exerts a reinforcing effect, improving the rigidity of the straight portion 34. In particular, the thickness dimension of the crimping piece 40 is set to be larger than the thickness dimension of the crimping portion 50, and the crimping piece 40 (i.e., the straight portion 34) has a certain thickness dimension, so that the rigidity of the straight portion 34 is stably improved. The straight portion 34 has a pair of two-face width portions 42, 42 and a pair of curved portions 44, 44. Therefore, the space is reduced compared to when the straight portion 34 is a perfect circle in plan view, and the rigidity of the straight portion 34 is improved compared to when the straight portion 34 is a rectangular shape in plan view, so that both miniaturization and improved rigidity are achieved. In addition, the circumferential dimension C of each two-face width portion 42 is set to be 1/4 times or more the major axis dimension L of the straight portion 34, and the circumferential dimension C of each two-face width portion 42 has a certain degree of size. This allows the area of each two-face width portion 42 to be larger, and the rigidity of each two-face width portion 42 to be improved. Furthermore, since the press-fit allowance of each two-face width portion 42 is larger than that of each curved portion 44, a larger press-fit fixing force is obtained in each two-face width portion 42, and by adopting multiple structures that improve the rigidity of each two-face width portion 42 as described above, the press-fit of the straight portion 34, which has an elongated cylindrical shape, can be realized without deformation of each two-face width portion 42. Furthermore, the press-fit of the straight portion 34 into the bracket member 76 is stably realized, and the resistance to the removal of the mount body 12 from the bracket member 76 can also be improved.

In addition, in the engine mount 10, the bracket member 76 is located below the crimping piece 40 and the step portion 39, and is spaced apart from the tapered portion 36 of the outer tubular metal fitting 20. In other words, the straight portion 34 of the outer tubular metal fitting 20 does not come into contact with the bracket member 76 in the axial direction (up and down direction), and this prevents the outer tubular metal fitting 20 and the bracket member 76 from hitting each other and generating abnormal noise due to component variations such as manufacturing errors.

In particular, in this embodiment, the lower portion of the bracket member 76 is a reduced diameter section 90 that reduces in diameter toward the bottom. This improves the rigidity of the bracket member 76 compared to when the bracket member is simply a straight tube. Furthermore, since the bracket member 76 and the outer tubular metal fitting 20 are spaced apart in the axial direction (up and down), and axial contact is avoided, the position of the mount body 12 relative to the bracket member 76 can be set with high precision even if there is variation in the components due to manufacturing errors, etc. Furthermore, by providing the reduced diameter section 90 to the bracket member 76, the engine mount 10 can be made even more compact.

In addition, in this embodiment, the vertical width dimension H of each two-face width portion 42 is set to be at least half the circumferential length dimension C of each two-face width portion 42. This ensures that the vertical width dimension H and rigidity of each two-face width portion 42 are sufficiently large, allowing stable press-fitting of the mount body 12 into the bracket member 76. It is preferable that the vertical width dimension H of each two-face width portion 42 be set to, for example, three times or less the circumferential length dimension C of each two-face width portion 42, which allows the outer cylindrical fitting 20, and therefore the engine mount 10, to be made smaller.

Although one embodiment of the present invention has been described in detail above, the present invention is in no way limited by the specific description of the embodiment, and can be implemented in various forms with various changes, modifications, improvements, etc. based on the knowledge of those skilled in the art, and it goes without saying that all such embodiments are included within the scope of the present invention as long as they do not deviate from the spirit of the present invention.

For example, in the above embodiment, a tapered reduced diameter portion 90 is provided at the bottom of the bracket member 76, but the shape of the bracket member is not limited thereto, and it may extend substantially straight over its entire length in the vertical direction.

In addition, in the above embodiment, the vertical width dimension H of each two-sided width portion 42 is set to be at least half the circumferential length dimension C of each two-sided width portion 42, but the vertical width dimension of each two-sided width portion is not limited.

In addition, in the above embodiment, the partition member 54 is composed of the partition member main body 56 and the bottom plate member 58, but in the partition member, instead of or in addition to the vibration-proof mechanism using an orifice passage as in the above embodiment, a known vibration-proof mechanism using a movable plate or movable membrane may be used in combination.

In the above embodiment, an engine mount is used as an example of a suspended type fluid-filled vibration-damping device, but the invention is not limited to this embodiment. The fluid-filled vibration-damping device according to the present invention may be a fluid-filled vibration-damping device for a vehicle other than an engine mount, such as a body mount or a differential mount, or may be a fluid-filled vibration-damping device for a vehicle other than a vehicle.

The outer bracket is not limited in shape as long as it is provided with a bracket member into which the straight portion of the outer tubular metal fitting is press-fitted, and it does not have to have a cylindrical portion, extension, or mounting portion. In addition, the suspended type fluid-filled vibration isolation device of the present invention does not have to include an inner bracket.

10 Engine mount (suspended type fluid-filled vibration isolation device)
Reference Signs List 12 mount body 14 inner bracket 16 outer bracket 18 inner shaft member 20 outer tubular metal fitting 22 main rubber elastic body 24 pressure-receiving chamber 26 flexible membrane 28 equilibrium chamber 30 bolt hole 32 tapered surface 34 straight portion 36 tapered portion 38 bent portion 39 step portion 40 crimping piece 42 two-face width portion 44 curved portion 46 seal rubber layer 48 fixing member 50 crimping portion 52 fluid chamber 54 partition member 56 partition member body 58 bottom plate member 60 circumferential groove 62, 64 communication hole 66 orifice passage 68, 70 bolt insertion hole 72 cushion rubber 74 bolt 76 bracket member 78 tubular portion 80 extension portion 82 bolt insertion hole 84 mounting portion 86 bolt 88 press-fit tubular portion 90 reduced diameter portion 92 linear portion 94 Arc-shaped portion 96 Inner flange-shaped portion 98 Central hole

Claims (3)

The inner shaft member is inserted into the lower opening of the outer tubular metal fitting, and the inner shaft member and the outer tubular metal fitting are connected by a main rubber elastic body.
A suspended type fluid-filled vibration isolation device in which a pressure-receiving chamber, the wall of which is partly constituted by the main rubber elastic body, and an equilibrium chamber, the wall of which is partly constituted by a flexible membrane, are formed inside, and in which a non-compressible fluid is filled in the pressure-receiving chamber and the equilibrium chamber,
The outer tubular metal member has an upper portion which is a straight portion extending with a constant cross section, and a lower portion which is a tapered portion whose diameter decreases downward,
a crimping piece is provided at an upper end of the outer tubular metal fitting, the crimping piece being press-crimped and fixed to a crimping portion of a fixing member fixed to the flexible film,
The thickness dimension of the crimping piece is made larger than the thickness dimension of the crimping portion,
the straight portion of the outer tubular member has an elongated cylindrical shape having a pair of linear two-face width portions when viewed in the axial direction and a pair of curved portions connecting the pair of two-face width portions to each other in the circumferential direction,
a bracket member into which the straight portion of the outer tubular member is press-fitted and fixed is provided,
the bracket member is spaced downward from the crimping piece of the outer tubular fitting,
the bracket member is spaced apart from the tapered portion of the outer tubular member,
a press-fit allowance of the straight portion in the two-face width portion with respect to the bracket member is set to be larger than a press-fit allowance of the straight portion in the curved portion with respect to the bracket member,
A suspended type fluid-filled vibration-damping device, wherein the circumferential length of the two-face width portion is at least 1/4 of the major axis of the straight portion. an upper portion of the bracket member is a press-fitting tubular portion into which the straight portion of the outer tubular fitting is press-fitted,
2. A suspended-type fluid-filled vibration-damping device as described in claim 1, wherein a lower portion of the bracket member is a tapered reduced diameter portion having a smaller diameter toward the bottom, and the reduced diameter portion of the bracket member is externally inserted into the tapered portion of the outer tubular fitting and is spaced axially downward from the tapered portion. The suspended type fluid-filled vibration isolation device according to claim 1 or 2, wherein the vertical width dimension of the two-sided width portion is at least half the circumferential length dimension of the two-sided width portion.

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