JP4284243B2 - Vibration isolator - Google Patents

Description

  The present invention relates to a vibration isolator used as a cabin mount for an agricultural machine such as a tractor or a construction machine such as a bulldozer or an engine mount for an industrial machine.

  As an anti-vibration device applied as an engine mount or the like, for example, as shown in Patent Literature 1 and Patent Literature 2, a substantially cylindrical shape in which a flange portion extending to the outer peripheral side is formed at an end portion on the outer side in the axial direction. An outer cylinder, a substantially cylindrical inner cylinder disposed on the inner peripheral side of the outer cylinder, and a rubber elastic body disposed between the outer cylinder and the inner cylinder. A pair of anti-vibration rubbers, and the pair of anti-vibration rubbers are connected and fixed to the bracket member by sandwiching the bracket member between the pair of flange portions while abutting the axially inner ends of each other The plate-like stay member and the stopper member, which are respectively positioned on the axially outer sides of the pair of rubber elastic bodies, are connected and fixed by bolts inserted through the pair of inner cylinders, and are sandwiched between these stay members and the stopper member. Axial Moving to is limited, there is known a so-called sandwich type.

  FIG. 4 shows an example of a conventional vibration isolator having the above structure. The vibration isolator 50 is applied, for example, as an engine mount in a vehicle, and attenuates and absorbs vibration input from an engine that is a vibration generating unit, and suppresses vibration transmission to the vehicle body that is a vibration receiving unit. .

  As shown in FIG. 4A, the vibration isolator 50 includes a pair of vibration isolating rubbers 52 having a symmetrical structure and shape along the axial direction. As shown in FIG. 5, the anti-vibration rubber 52 is provided with a rubber elastic body 58 disposed between the outer cylinder 54 and the inner cylinder 56. The outer cylinder 54 is formed with a ring-shaped flange portion 60 that extends to the outer peripheral side at an end portion on the outer side in the axial direction. The rubber elastic body 58 is vulcanized and bonded to the inner peripheral surface of the outer cylinder 54 and the flange portion 60, and is also vulcanized and bonded to the outer peripheral surface of the inner cylinder 56 to elastically connect the outer cylinder 54 and the inner cylinder 56. It is connected.

  In the vibration isolator 50, the plate-shaped bracket 62 is sandwiched between the pair of flange portions 60 while the axial ends of the pair of anti-vibration rubbers 52 configured as described above face each other, and a pair of The anti-vibration rubber 52 is sandwiched between the connecting stay 64 and the stopper plate 66 from the outside in the axial direction. Here, the bracket 62 is connected and fixed to the engine side of the vehicle, and the connection stay 64 is connected and fixed to the vehicle body side of the vehicle. The stopper plate 66 and the connecting stay 64 are respectively provided with insertion holes 65 and 67 penetrating in the axial direction.

  In the vibration isolator 50, the bolt 68 is inserted into the insertion hole 67 of the stopper plate 66 from the axial direction outside, the pair of inner cylinders 56, and the insertion hole 65 of the connecting stay 64, and a small diameter is formed at the tip of the bolt 68. The washer 70 is fitted, and the nut 72 is further screwed into the assembly. At this time, the nut 70 is screwed into the bolt 68 until one end portions of the inner cylinder 56 in the pair of vibration-proof rubbers 52 are in pressure contact with each other. Thereby, the pair of rubber elastic bodies 58 are compressed by a predetermined preliminary compression amount (PC shown in FIG. 5) along the axial direction, respectively, and can generate a required reaction force against the load along the axial direction. It becomes a state. In the vibration isolator 50, when vibration is input via the pair of fixed plates 64 or the bracket 62, the rubber elastic bodies 58 in the pair of vibration isolating rubbers 52 are elastically deformed to attenuate and absorb the input vibration.

  By the way, in the vibration isolator 50 having the above structure, when an excessive compressive load (load load) is input via the connecting stay 64 or the bracket 62, the rubber elastic body 58 is excessively deformed to exceed the precompression amount. It is necessary to prevent this from occurring. That is, in the vibration isolator 50, for example, if excessive compression deformation exceeding the precompression amount occurs in the axial direction in the rubber elastic body 58 on the stopper plate 66 side (upper side in FIG. 4), the connection stay 64 side (FIG. The rubber elastic body 58 on the lower side in FIG. 4 is deformed (restored) in the tension direction, and the preliminary compression is lost. As a result, the connecting stay 64 hardly receives an elastic reaction force from the other rubber elastic body 58 and vibrates with little resistance to the vibration input, that is, between the bracket 62 and the connecting stay 64. It will be in the state where the backlash occurred.

Therefore, as shown in FIG. 5, the rubber elastic body 58 is integrally formed with a stopper portion 72 on the outer periphery thereof, and the stopper portion 72 is formed along the axial direction of the flange portion of the outer cylinder 54. It overlaps 60 and faces the connecting stay 64 or the stopper plate 66 at a predetermined interval. Thereby, for example, as shown in FIG. 4B, when an excessive compressive load is input to the vibration-proof rubber 52 on the stopper plate 66 side and the rubber elastic body 58 is deformed, the stopper portion 72 is moved to the stopper plate 66. The anti-vibration rubber 52 is prevented from undergoing large deformation (compression deformation) exceeding the pre-compression amount due to its deformation resistance.
Japanese Utility Model Publication No.59-191452 Japanese Utility Model Publication No. 60-7433

  However, in the vibration isolator 50 as described above, an excessive compressive load (load load) is input to one rubber elastic body 58 via the connecting stay 64 or the bracket 62, as shown in FIG. When the stopper portion 72 is in close contact with the stopper plate 66, a phenomenon in which the stopper portion 72 sticks to the stopper plate 66 due to the influence of rubber viscosity or the like (so-called sticking phenomenon) may occur. When such a sticking phenomenon progresses, the stopper portion 72 adheres to the stopper plate 66 and a local breakage occurs, which may be a factor of reducing the durability of the vibration isolator 50. Such a sticky phenomenon can occur in the same manner when an excessive compressive load (load load) is input to the other rubber elastic body 58 and the stopper portion 72 of the rubber elastic body 58 is in pressure contact with the connecting stay 64. .

  In view of the above fact, the object of the present invention is to provide an anti-vibration that can prevent the sticking phenomenon of the stay member and the stopper member from occurring in the stopper portion of the rubber elastic body even if an excessive compressive load is input to the rubber elastic body. To provide an apparatus.

  In order to achieve the above object, a vibration isolator according to the present invention is connected to one of a vibration generating part and a vibration receiving part via a bracket member, and extends to the outer peripheral side at an axially outer end. A substantially cylindrical outer tube formed on the inner side of the outer cylinder, connected to the other of the vibration generating part and the vibration receiving part via a stay member, A rubber elastic body disposed between the outer cylinder and the inner cylinder, and a pair of anti-vibration rubbers provided respectively. While abutting each other, a bracket member is sandwiched between the pair of flange portions to be connected and fixed to the bracket member, and a fastening member that is inserted through the pair of inner cylinders to the outside of the pair of rubber elastic bodies in the axial direction. Connected to stay member and stopper member A vibration isolator that is sandwiched between the stay member and the stopper member to restrict movement in the axial direction, on the outer peripheral side of the rubber elastic body, on the outer side in the axial direction of the flange portion. A stopper portion that is disposed and fixed to the flange portion is integrally formed. The stopper portion extends along a circumferential direction centering on the inner cylinder, and the stopper member is attached to one of the stay member and the stopper member. A stopper support surface is formed opposite to each other at a predetermined interval along the axial direction, and a ring-shaped stopper fitting is fixed to the stopper support surface.

  In the vibration isolator according to the present invention, a stopper portion fixed to the flange portion of the outer cylinder is integrally formed on the outer peripheral side of the rubber elastic body, and the stopper portion extends along the circumferential direction centering on the inner cylinder. A bracket support member is formed by forming a stopper support surface on one of the stay member and the stopper member facing each other at a predetermined interval along the axial direction, and fixing a ring-shaped stopper fitting to the stopper support surface. Alternatively, even if an excessive compressive load is input to one rubber elastic body via the stay member, the stopper portion is always pressed against the stay member or the stopper member via the stopper fitting, and the rubber portion of the stopper portion is the stay member. Or, since there is no direct pressure contact with the stopper member, the phenomenon that the stopper part sticks to the stay member or the stopper member due to the influence of rubber viscosity or the like (so-called stickiness) ) Can be reliably prevented that may occur.

  As a result, according to the vibration isolator according to the present invention, even if an excessive compressive load is input to the rubber elastic body, the sticking phenomenon to the stay member and the stopper member is surely prevented from occurring in the stopper portion of the rubber elastic body. it can.

  As described above, according to the vibration isolator of the present invention, even if an excessive compressive load is input to the rubber elastic body, it is possible to prevent the sticking phenomenon of the stay member and the stopper member from occurring in the stopper portion of the rubber elastic body. .

  Hereinafter, a vibration isolator according to an embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 shows a vibration isolator according to an embodiment of the present invention. The vibration isolator 10 is applied, for example, as an engine mount in a vehicle, and attenuates and absorbs vibrations input from an engine that is a vibration generating unit to a vehicle body that is a vibration receiving unit, and suppresses vibration transmission to the vehicle body. It is.

  As shown in FIG. 1A, the vibration isolator 10 includes a pair of vibration isolating rubbers 12 having a symmetrical structure and shape along the axial direction. The anti-vibration rubber 12 includes an outer cylinder 14 formed in a substantially cylindrical shape, a cylindrical inner cylinder 16 disposed substantially coaxially on the inner peripheral side of the outer cylinder 14, and the outer cylinder 14 and the inner A rubber elastic body 18 disposed between the cylinder 16 and the cylinder 16 is provided.

  Here, the outer cylinder 14 is formed with a flange portion 15 extending to the outer peripheral side at an axially outer end portion (outer end portion). The inner cylinder 16 has an axially inner end (inner end) positioned between the flange 15 and the inner end of the outer cylinder 14 along the axial direction, and an outer end of the inner cylinder 16 in the outer cylinder 14. Protruding from. The rubber elastic body 18 is vulcanized and bonded to the inner peripheral surface of the outer cylinder 14 and the flange portion 15, and is vulcanized and bonded to the outer peripheral surface of the inner cylinder 16 to elastically connect the outer cylinder 14 and the inner cylinder 16. It is connected.

  As shown in FIG. 1, the rubber elastic body 18 is formed with a groove portion 20 extending in the circumferential direction on the outer surface on the outer side in the axial direction over the entire circumference. This groove part 20 is arrange | positioned so that it may correspond with the inner peripheral edge part of the flange part 15 of the outer cylinder 14 along a radial direction. In the rubber elastic body 18, the inner peripheral side portion is a vibration absorbing portion 22 through the groove portion 20, and the outer peripheral side portion is a stopper portion 24. The vibration absorbing portion 22 of the rubber elastic body 18 absorbs input vibration by elastically deforming when vibration is input. Moreover, the stopper part 24 is arrange | positioned so that it may overlap with the flange part 15 of the outer cylinder 14 along an axial direction, and the cross-sectional shape along the radial direction is made into the substantially rectangular shape. A flat stopper support surface 26 is formed on the stopper portion 24 on the outer side in the axial direction, and this stopper support surface 26 extends in an annular shape along the circumferential direction centering on the inner cylinder 16.

  As shown in FIG. 2A, the anti-vibration rubber 12 is provided with a metal stopper fitting 28 formed in a thin ring shape having a substantially constant thickness on the stopper support surface 26. The stopper fitting 28 is fixed to the stopper support surface 26 by vulcanization and covers the entire stopper support surface 26. The stopper fitting 28 is arranged so that the inner peripheral end thereof extends in the circumferential direction along the outer peripheral end of the groove portion 20 of the rubber elastic body 18. Here, the stopper fitting 28 is made of a metal material such as iron or aluminum. However, the stopper fitting 28 may be formed of a resin material such as nylon in addition to the metal material and fixed to the stopper support surface 26 with an adhesive or the like.

  In the vibration isolator 10, as shown in FIG. 1B, a thick plate-like bracket is placed between the pair of flange portions 15 while the axially inner ends of the pair of vibration isolating rubbers 12 face each other. In addition, the pair of anti-vibration rubbers 12 is sandwiched between the connecting stay 30 and the stopper plate 32 from the outside in the axial direction. Here, the bracket 34 is connected to the engine side of the vehicle, and the bracket 34 is connected to the vibration isolator 10 and has a circular opening 36 having an inner diameter corresponding to the outer diameter of the outer cylinder 14 (see FIG. 1 (A)) is perforated. When the bracket 34 is sandwiched between the pair of flange portions 15, the inner ends of the pair of outer cylinders 14 are inserted into the openings 36 of the brackets 34 from the outside in the axial direction, and the flange portions 15 of these outer cylinders 14 are inserted. Thus, the bracket 34 is clamped.

  As shown in FIG. 1, a connecting stay 30 disposed on the outer side in the axial direction of one (the lower side in FIG. 1) vibration isolating rubber 12 is connected to the vehicle body side of the vehicle. An insertion hole 31 penetrating in the direction is formed. Further, an insertion hole 33 penetrating in the axial direction is also formed in the stopper plate 32 disposed on the outer side in the axial direction of the other (upper side in FIG. 1) vibration isolating rubber 12. The stopper plate is centered on the insertion hole 33. 32 extends to the outer peripheral side from the anti-vibration rubber 12. When the vibration isolator 10 is assembled, the connecting stay 30, the stopper plate 32, and the pair of vibration isolating rubbers 12 are respectively arranged so that the insertion hole 31 and the insertion hole 33 coincide with the openings of the pair of inner cylinders 16, respectively. The position is adjusted.

  As shown in FIG. 1C, the vibration isolator 10 has a single bolt 38 inserted into the insertion hole 33 of the stopper plate 32, the pair of inner cylinders 16, and the insertion holes 31 of the connecting stay 30 from the outside in the axial direction. After the washer 40 is fitted into the tip of the bolt 38 that is inserted and protrudes from the insertion hole 31, the nut 42 is screwed into the assembly. At this time, the nut 42 is screwed into the bolt 38 until one end portions of the inner cylinder 16 in the pair of vibration isolating rubbers 12 are in pressure contact with each other. Thereby, the rubber elastic bodies 18 in the pair of vibration-insulating rubbers 12 are respectively compressed in the axial direction by a predetermined preliminary compression amount (PC shown in FIG. 2B), and against the input load along the axial direction. The required reaction force can be generated. That is, in the vibration isolator 10, the reaction force against the load applied by the rubber elastic body 18 can be increased as the pre-compression amount of the rubber elastic body 18 is increased. On the contrary, the pre-compression amount of the rubber elastic body 18 is increased. The smaller the force, the less the reaction force against the load applied by the rubber elastic body 18.

  In the vibration isolator 10 configured as described above, for example, when vibration from an engine that is a vibration generating unit is input via the bracket 34, the rubber elastic body 18 in the pair of vibration isolating rubbers 12 extends along the axial direction. Each elastically deforms in the opposite direction (compression direction or tensile direction), and the input vibration is attenuated and absorbed by the rubber elastic body 18 of the anti-vibration rubber 12.

  In the vibration isolator 10, as shown in FIG. 1C, the stopper fitting 28 fixed to one rubber elastic body 18 in a state where the pair of rubber elastic bodies 18 are compressed by a predetermined preliminary compression amount. A gap S is formed along the axial direction between the connecting stay 30 and the connecting stay 30, and a gap S is also formed along the axial direction between the stopper fitting 28 fixed to the other rubber elastic body 18 and the stopper plate 32. Is formed. These gaps S are set such that the width along the axial direction is smaller than the pre-compression amount (= PC) of the rubber elastic body 18.

  FIG. 3 shows a state where an excessive load is input to the vibration isolator 10 through one of the connecting stay 30 and the bracket 34. When an excessive load is input to the vibration isolator 10, one (upper in FIG. 3) rubber elastic body 18 is elastically deformed in the compression direction, and the other (lower in FIG. 3) rubber elastic body 18 is in the pulling direction. Elastically deforms. At this time, when one of the rubber elastic bodies 18 undergoes compressive deformation close to the preliminary compression amount, the stopper fitting 28 fixed to the rubber elastic body 18 comes into pressure contact with the stopper plate 32. Accordingly, the stopper portion 24 causes an elastic reaction force to act on the stopper plate 32, and this reaction force limits the compression deformation of the rubber elastic body 18. That is, when one rubber elastic body 18 is compressed and deformed by an excessive load and the stopper portion 24 is pressed against the stopper plate 32 via the stopper fitting 28, the cross-sectional area of the rubber elastic body 18 that receives the load is the stopper portion. Since it increases by the area of 24, the compression load-strain characteristic of the rubber elastic body 18 rises steeply, and the rubber elastic body 18 is restricted from undergoing compressive deformation exceeding the pre-compression amount.

  In the vibration isolator 10 according to the present embodiment described above, the stopper portion 24 fixed to the flange portion 15 of the outer cylinder 14 is integrally formed on the outer peripheral side of the rubber elastic body 18, and the inner cylinder is formed on the stopper portion 24. A stopper support surface 26 that extends along the circumferential direction centered at 16 and that faces one of the connecting stay 30 and the stopper plate 32 at a predetermined interval along the axial direction is formed. Since the ring-shaped stopper fitting 28 is fixed to 26, even if an excessive compressive load is input to one rubber elastic body 18 via the bracket 34 or the connecting stay 30, the stopper portion 24 is always made of metal. 28, the connecting stay 30 or the stopper plate 32 is in pressure contact with each other, and the rubber portion of the stopper portion is not in direct contact with the stay member or the stopper member. Runode phenomenon that the stopper portion 24 sticks to the joint stay 30 or the stopper plate 32 due to the influence of the viscosity or the like of the rubber forming the rubber elastic body 18 (so-called stickiness phenomenon) can be reliably prevented that may occur.

  As a result, according to the vibration isolator 10 according to the present embodiment, even if an excessive compressive load is input to the rubber elastic body 18, the sticking phenomenon of the connecting stay 30 or the stopper plate 32 on the stopper portion 24 of the rubber elastic body 18. Can be reliably prevented.

  Further, in the vibration isolator 10 according to the present embodiment, since the rubber elastic body 18 is formed with the groove 20 extending in the circumferential direction along the inner peripheral end of the stopper fitting 28, the stopper portion of the rubber elastic body 18. When 24 is pressed against the connecting stay 30 or the stopper plate 32 via the stopper fitting 28, it can be deformed in the compression direction independently of the vibration absorbing portion 22 by an amount corresponding to the depth of the groove portion 20. Even if the elastic body 18 is repeatedly subjected to an excessive compressive load, it is possible to prevent cracks from occurring near the boundary between the stopper portion 24 and the vibration absorbing portion 22.

  FIG. 3C shows a modified example of the vibration isolating rubber applicable to the vibration isolating apparatus according to the embodiment of the present invention. The anti-vibration rubber 44 shown in FIG. 3C is different from the anti-vibration rubber 12 shown in FIG. 1 in that the intermediate portion between the flange portion 15 of the outer cylinder 14 and the stopper fitting 28 in the stopper portion 24 of the rubber elastic body 18. The ring-shaped partition metal fitting 46 is embedded and fixed. Similarly to the stopper fitting 28, the partition fitting 46 is made of, for example, a metal material such as iron or aluminum. When the rubber elastic body 18 is molded, it is loaded into the mold as an insert core. And vulcanized and bonded. By embedding the partition fitting 46 in the stopper portion 24 of the rubber elastic body 44, the rigidity along the axial direction of the stopper portion 24 can be increased. Even when is inputted, it is possible to prevent the rubber elastic body 18 from being compressed and deformed exceeding the pre-compression amount.

  In the anti-vibration rubber 44 shown in FIG. 3 (C), only one partition fitting 46 is embedded and fixed in the stopper portion 24 in the rubber elastic body 18, but two or more such partition fittings 46 are provided. Further, the stopper portion 24 may be embedded and fixed, and the rigidity of the stopper portion 24 along the axial direction can be increased as the number of the partition metal fittings 46 is increased.

It is side surface sectional drawing which shows the structure of the vibration isolator which concerns on embodiment of this invention, (A) is the state which decomposed | disassembled the vibration isolator along the axial direction, (B) matched a pair of anti-vibration rubber | gum mutually The state (C) shows the state assembled as a vibration isolator. (A) and (B) are a top view and a side sectional view of the vibration isolator in the vibration isolator shown in FIG. 1, and (C) is a rubber elastic body applicable to the vibration isolator according to the embodiment of the present invention. It is side surface sectional drawing which shows a modification. It is side surface sectional drawing which shows the state into which the excessive compression load was input into the vibration isolator shown by FIG. It is side surface sectional drawing which shows the structure of the conventional vibration isolator, (A) shows the state in which the load is not input into the vibration isolator, (B) shows the state in which the load is input into the vibration isolator, respectively. Yes. It is side surface sectional drawing which shows the structure of the vibration isolator in the vibration isolator shown by FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Anti-vibration device 12 Anti-vibration rubber 14 Outer cylinder 15 Flange part 16 Inner cylinder 18 Rubber elastic body 20 Groove part 22 Damping part 24 Stopper part 26 Stopper support surface 28 Stopper metal fitting 30 Connection stay (stay member)
32 Stopper plate (stopper member)
34 Bracket (Bracket member)
38 bolt (fastening member)
40 Washer (fastening member)
42 Nut (fastening member)
44 Anti-vibration rubber 46 Partition bracket

Claims (3)

A substantially cylindrical outer cylinder that is connected to one of the vibration generating part and the vibration receiving part via a bracket member, and has a flange part that extends to the outer peripheral side at the outer end in the axial direction, and the vibration generating part and the vibration A substantially cylindrical inner cylinder connected to the other receiving portion via a stay member and disposed on the inner peripheral side of the outer cylinder, and a rubber elasticity disposed between the outer cylinder and the inner cylinder A pair of anti-vibration rubbers each provided with a body,
The pair of anti-vibration rubbers are connected and fixed to the bracket member by sandwiching the bracket member between the pair of flange portions while abutting the axially inner ends thereof, and the pair of inner cylinders. The pair of rubber elastic bodies are connected and fixed to the stay member and the stopper member respectively positioned on the outer sides in the axial direction by the inserted fastening members, and are sandwiched between these stay members and the stopper member to move in the axial direction. Anti-vibration device limited,
On the outer peripheral side of the rubber elastic body, a stopper portion that is disposed on the outer side in the axial direction of the flange portion and fixed to the flange portion is integrally formed,
A stopper support surface is formed on the stopper portion along a circumferential direction centering on the inner cylinder, and is opposed to one of the stay member and the stopper member at a predetermined interval along the axial direction. A vibration isolator having a ring-shaped stopper fitting fixed to the stopper support surface.   The vibration isolator according to claim 1, wherein a ring-shaped partition fitting is embedded and fixed between the flange portion and the stopper fitting in the stopper portion.   The vibration isolator according to claim 1 or 2, wherein a groove portion extending in the circumferential direction along an inner peripheral end portion of the stopper fitting is formed in the rubber elastic body.

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