JP2011064194A - Buffer and metal cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a buffer having stably improved vibration damping characteristics, and to provide a metal cover using the same when mounted. <P>SOLUTION: The buffer 31 is arranged between a bolt boss 34 provided on an exhaust manifold 1 as a vibration source and a heat insulator 3 to be connected thereto for connecting the bolt boss 34 provided on the exhaust manifold 1 to the heat insulator 3 to damp the transmission of vibration from the bolt boss 34 provided on the exhaust manifold 1 to the heat insulator 3. It includes a spiral spring 32 for damping the vibration, a grommet 33 for joining the spiral spring 32 to the heat insulator 3, and a collar member 39 existing between a mounting bolt 6 to be fastened to the bolt boss 34 provided on the exhaust manifold 1 and the spiral spring 32, the spiral spring 32 being formed of a spiral wire rod. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a shock absorber used for mounting a cover, a housing, or the like on a member that generates vibration, for example. More specifically, the cover is attached to an exhaust manifold (for an internal combustion engine). Hereinafter, the present invention relates to a shock absorber used for attachment to an exhaust manifold and the like, and a metal cover attached using the shock absorber.

  For example, as shown in FIG. 9, the exhaust manifold 1 attached to the side surface of the engine 2 vibrates itself because combustion exhaust gas pulsating in pressure and temperature passes through the inside according to the driving of the engine. , Generate vibration noise. Further, the exhaust manifold 1 is heated by the high-temperature combustion exhaust gas passing through the interior, and the exhaust manifold 1 itself generates heat. As described above, the heat insulator 3 is attached so as to cover the exhaust manifold 1 in order to prevent the vibration sound and heat generated from the exhaust manifold 1 from propagating to the periphery of the engine 2.

  However, if the heat insulator 3 is directly attached to the exhaust manifold 1 or the engine 2 that vibrates, the heat insulator 3 resonates and the heat insulator 3 itself becomes a vibration source, which may increase noise.

  Therefore, in Patent Document 1, as described above, a shock absorber 5 having a floating mount structure for attaching the heat insulator 3 to the exhaust manifold 1 of the engine 2 is proposed (see FIG. 17). FIG. 17 shows a sectional view of the shock absorber 5 proposed in the following patent document.

  The shock absorber 5 of the prior art is formed of an annular buffer member 8 formed by knitting metal fibers in a mesh shape and forming it into a flat mat shape, and an aluminum alloy, and has a substantially S-shaped cross section. It is comprised with the grommet 9 which is a member, and the collar member 10 arrange | positioned between the buffer member 8 and the attachment bolt 6. FIG.

  A gap 17 in the axial direction and the radial direction of the mounting bolt 6 is formed between the collar member 10 and the buffer member 8. The clearance 17 suppresses transmission of vibration input from the exhaust manifold 1 from the collar member 10 to the buffer member 8, that is, has excellent vibration damping properties.

  Specifically, the buffer member 8 itself bends due to the vibration transmitted from the collar member 10 to the buffer member 8. By such a bending motion, the shock absorber 5 can convert the vibration energy of the vibration transmitted from the collar member 10 into the bending kinetic energy of the buffer member 8 and suppress the vibration transmitted to the heat insulator 3. Has been.

  However, by providing the gap 17 between the collar member 10 and the buffer member 8, the buffer member 8 vibrates in the collar member 10, so that the buffer member 8 collides with the collar member 10. There is a risk that a rattling noise may occur due to the collision between the buffer member 8 and the collar member 10. For example, this noise has a considerably large sound pressure in an audible frequency band of 150 Hz or less, and the gap 17 for suppressing vibration transmission from the collar member 10 to the buffer member 8 is formed between the collar member 10 and the buffer member 8. As a result, there was a risk of new noise being generated. The generation of noise in this way is considered to be a new vibration and to inhibit the vibration control.

  Further, the buffer member 8 formed by knitting metal fibers into a mesh shape and forming a mat shape tends to vary the cutting size of the metal fibers to a predetermined fiber length, and affects the elasticity of the buffer member 8. There is a possibility that the vibration damping performance of the device 5 may vary.

Japanese Patent Laid-Open No. 2004-360596

  An object of the present invention is to provide a shock absorber having a stable and excellent vibration damping property and a metal cover to be attached using the shock absorber.

The present invention is arranged between a vibration-side target member that is a vibration source and a connection target member that is a connection target, connects the vibration-side target member and the connection target member, and from the vibration-side target member A shock absorber for buffering transmission of vibration to a connection target member, the buffer member for buffering the vibration, a coupling member for coupling the buffer member and the connection target member, and a vibration side target member A collar member interposed between the fastening member and the buffer member; the coupling member surrounding the buffer member; and a first holding portion for holding the connection target member on a radially outer side; and the buffer member A second holding part that holds the member inside the diameter, and a connecting part that connects the first holding part and the second holding part, and the buffer member is gradually increased in the height direction along the spiral direction. changes in a spiral spiral wire Configured, the collar member mounting portion to allow the mounting of the collar member, with provided in the radial center portion of the helical spiral, a held portion held by the second holding portion, the diameter of the helical spiral Rutotomoni provided in the outward portion, relative to the vibration-side target member, the fastening member insertion of the held portion is disposed in a direction away from the collar member mounting portion, said collar member to permit insertion of said fastening member And a shock-absorbing member holding portion for holding the collar member mounting portion on the radially outer side.

  The vibration-side target member can be, for example, an engine body such as an automobile, an exhaust pipe (particularly an exhaust manifold) or a catalyst portion in a portion mounted on the engine, a frame constituting a vehicle body, or the like.

The connection target member may be a heat insulator that covers and covers the engine main body, the exhaust pipe, the catalyst portion, or the like, or an undercover that covers the bottom of the vehicle body.
The coupling member may be a so-called grommet.

The fastening member can be, for example, a member such as a bolt or nut for screwing the vibration side target member and the connection target member, or a caulking jig by caulking.
The spiral spiral shape that gradually changes in the height direction along the spiral direction is a three-dimensional curve that moves in a direction having a vertical component on the swivel plane as it turns, and can be a so-called helix.

The wire is a wire that is appropriately selected according to various use conditions such as the frequency band and amplitude of vibration to be suppressed, temperature under use, etc., and is round, oval, substantially rectangular, or any other closed curved surface shape. It can be set as the wire which is the cross-sectional shape.
The inside of the diameter is the center side with respect to the outside in a plan view in the spiral spiral shape , and the outside of the diameter is the outside in a plan view with respect to the center in the spiral spiral shape .

According to the present invention, it is possible to stably exhibit excellent vibration damping properties.
Specifically, the buffer member is formed of a spiral spiral wire, and a collar member mounting portion that allows the collar member to be mounted is provided at a central portion in the radial direction of the spiral spiral. Since the buffer member holding portion to be held is provided on the outer diameter side of the collar member, the buffer member itself formed of a spiral spiral wire performs a bending motion due to the vibration transmitted from the collar member to the buffer member. By such a bending motion, the shock absorber can convert the vibration energy of the vibration transmitted from the collar member into the bending motion energy of the buffer member and suppress the vibration transmitted to the connection target member.

In addition, the collar member mounting portion that allows the collar member to be mounted is provided in the central portion in the radial direction of the spiral spiral , and the buffer member holding portion that holds the color member mounting portion is provided outside the diameter of the color member. In addition, transmission of vibration can be suppressed without collision between the buffer member and the collar member. Therefore, vibration transmission from the collar member to the buffer member can be suppressed, that is, excellent damping performance can be achieved without generating a rattling noise due to the collision between the buffer member and the collar member.

In addition, since the buffer member is formed of a spiral spiral wire, there is less variation in the product compared to a buffer member formed by knitting metal fibers into a mesh and forming a mat. Therefore, a buffer member having stable elasticity can be configured. Therefore, it is possible to configure a shock absorber having stable vibration damping properties.

Specifically, since the buffer member is composed of a wire formed into a spiral spiral shape , there is no need to handle fine inorganic fibers, and the fiber length management and the final product in the process of cutting the inorganic fibers into a predetermined fiber length This eliminates the difficulty of high-precision management of the dimensional accuracy in the processing step of the above-described processing. Thereby, dimensional accuracy can be improved and the accuracy and stability of the damping performance of the shock absorber can be improved.
Therefore, by setting the shock absorber to the above-described configuration, the vibration-side target member that is the vibration source and the connection target member can be connected without transmitting vibration.

Further, the buffer member is formed in a spiral spiral shape that gradually changes in the height direction along the spiral direction, and the held portion is away from the collar member mounting portion with respect to the vibration side target member. The vibration damping performance in the shock absorber can be improved.

Specifically, by forming the buffer member in a spiral spiral shape, the elasticity in the height direction can be adjusted in addition to the elasticity in the plane direction. That is, it is possible to adjust the elasticity of the buffer member that greatly affects the damping performance of the buffer member in three dimensions.

  Further, by disposing the buffer member in a direction in which the held portion is separated from the collar member mounting portion with respect to the vibration side target member, the diameter of the spiral spiral buffer member from the inner diameter color member mounting portion becomes larger. The outer held portion is separated from the vibration side target member. That is, the connection target member held by the first holding portion of the connection member that holds the held portion by the second holding portion is arranged farther from the vibration side target member than the collar member wound around the color member mounting portion. The Rukoto.

  Therefore, even when the connection target member itself vibrates due to the vibration transmitted through the collar member and the buffer member, it is compared with the case where the color member is arranged farther from the vibration side target member than the connection target member. Thus, the possibility that the connection target member itself collides with the vibration side target member can be reduced. Therefore, the generation of noise due to the collision between the connection target member itself and the vibration side target member can be suppressed.
As described above, the damping performance can be further improved by adopting the above-described configuration of the shock absorber.

As an aspect of this invention, the pitch angle of the helical spiral can be formed by 5 degrees or less.
In the spiral spiral shape, the pitch angle is an angle of the wound wire rod with respect to the horizontal direction perpendicular to the height direction that gradually changes along the spiral direction.

  According to the present invention, it is possible to configure a shock absorber having moderate elasticity in the three-dimensional direction. Specifically, when the pitch angle is set large, the height of the spiral spiral increases, and the elastic force in the height direction can be improved. On the other hand, the elasticity in the horizontal direction is reduced. That is, the balance of elasticity in the three-dimensional direction of the spiral spiral buffer member is lost, blurring increases in the elastic support state, and a sufficient vibration damping effect cannot be obtained. In this way, by forming the spiral spiral pitch angle at 5 degrees or less, the balance of elasticity in the three-dimensional direction is maintained while achieving the effect of forming the buffer member as described above in the spiral spiral form. A sufficient damping effect can be obtained.

  As an aspect of the present invention, the collar member mounting portion and the held portion are formed in an arc shape, and the buffer member holding portion is fitted to allow the collar member mounting portion to be fitted on the cylindrical side surface. It can be formed by a landing recess.

According to this invention, the buffer member and the collar member can be easily fitted, and the held portion can be held by the second holding portion.
Specifically, the collar member mounting portion and the held portion are formed in an arc shape, and the buffer member holding portion is formed by a fitting recess that allows the collar member mounting portion to be fitted on the cylindrical side surface. Therefore, the buffer member and the collar member can be easily fitted by fitting the collar member mounting portion formed in the arc shape into the fitting recess in the side surface of the cylindrical color member. In addition, since the collar member mounting portion formed in an arc shape and the fitting recess formed in the cylindrical side surface are fitted, the buffer member and the collar member can be easily formed regardless of the circumferential position with respect to the collar member. Can be fitted.
Moreover, since the said to-be-held part was formed in circular arc shape, it can hold | maintain with a 2nd holding | maintenance part regardless of the position of the circumferential direction.

  Thus, since the buffer member and the collar member can be easily fitted and the held portion can be held by the second holding portion, the assembling property of the buffer device can be improved.

  Further, for example, the collar member mounting portion formed in an arc shape is compared with the case where the collar member mounting portion of the buffer member is mounted on the buffer member holding portion of the color member using another member. The number of parts can be reduced by fitting in the fitting recess on the side surface of the collar member formed in the above. Accordingly, it is possible to reduce the weight and cost of the shock absorber.

As an aspect of the present invention, a gap can be provided between the buffer member holding portion and the collar member mounting portion, and between the second holding portion and the held portion.
With this configuration, it is possible to further improve the damping performance of the shock absorber. Specifically, since the gap is formed in a state in which the collar member mounting portion and the held portion formed in an arc shape are held by the fitting recess and the second holding portion, the collar member mounting portion, the fitting recess, and the held portion The vibration input through the collar member can be absorbed by the gap without causing a collision sound in the part and the second holding part. Further, the heat transfer can be blocked by the gap.

As an aspect of the present invention, the collar member mounting portion and the held portion can be formed in an arc shape having a central angle of 240 degrees or more and 300 degrees or less.
The circular arc shape having a central angle of 240 degrees or more and 300 degrees or less is an arc that is formed at a predetermined angle along the spiral direction from the end of the spiral spiral buffer member and does not change.

  With this configuration, it is possible to improve the product reliability of the shock absorber having high vibration damping properties. Specifically, the collar member mounting portion and the held portion are formed in an arc shape with a central angle of 240 degrees or more and 300 degrees or less, so that the collar member mounting portion and the held portion formed in an arc shape are fitted. In a state where the concave portion and the second holding portion hold the gap while providing a gap, it is possible to prevent inadvertent detachment. Therefore, stable vibration control can be ensured.

  Further, as an aspect of the present invention, the buffer member is formed by plastic working an alloy composed of Al content of 2 to 12% by weight, the balance Fe and inevitable impurities, cold-rolled the plastic-worked alloy, and cold-rolled. By annealing the alloy after processing, it can be composed of a wire rod made of Fe-Al vibration-damping alloy having a spring property so that the average crystal grain size is 250 μm or less.

With this configuration, it is possible to easily process a shock absorber having higher vibration damping properties.
Specifically, since the shock absorbing member is made of an Fe-Al vibration damping alloy having a vibration damping coefficient significantly larger than that of the conventional vibration damping metal, the vibration transmitted from the collar member to the shock absorbing member is caused by the vibration damping alloy itself. The amplitude can be damped based on a large vibration damping coefficient. Therefore, a great damping action can be realized by the damping alloy itself.

Moreover, since Fe-Al damping alloy has excellent workability, insulation, permeability, damping, high strength, etc., it is easily processed into a spiral spiral to form a highly insulating buffer member. be able to. Therefore, it is possible to easily process a shock absorber having higher vibration damping properties.

  Further, as an aspect of the present invention, each of the collar member, the buffer member, the coupling member, and the connection target member is made of materials that are close to each other in ionization tendency to prevent the occurrence of electrolytic corrosion. Can do.

  With this configuration, it is possible to improve the product reliability of the shock absorber having high vibration damping properties. Specifically, since the collar member, the buffer member, the coupling member, and the connection target member are composed of materials that are close to each other in ionization tendency, so-called galvanic corrosion, which is generated between materials having greatly different ionization tendencies. Can be prevented. That is, the corrosion resistance of the shock absorber can be improved and the life of the shock absorber can be extended.

  Therefore, it is possible to prevent functional deterioration that may affect the damping performance of the shock absorber, such as a decrease in the holding force of the holding portion due to corrosion and a decrease in the elasticity of the shock absorber, and improve the product reliability of the shock absorber. can do.

  Further, the present invention is a metal cover having a three-dimensional shape formed of one or a plurality of aluminum alloy plates each having a corrugated shape extending in a direction intersecting with each other. The corrugated shape is crushed to form a substantially flat plate shape, and either one of the intersecting directions is defined as a direction intersecting a main ridge line corresponding portion constituting the three-dimensional shape, and the above-described shock absorber The vibration side target member is configured by an internal combustion engine and / or its exhaust path, and the crushing target portion is held by the first holding portion.

  According to the present invention, for example, a metal cover capable of suppressing heat dissipation and vibration transmission from an internal combustion engine such as an automobile and / or its exhaust path can be configured.

Specifically, for example, in order to attach a metal cover made of a material having an appropriate heat resistance performance with the above-described shock absorber having high vibration damping properties, heat dissipation from the internal combustion engine as a heat source and / or its exhaust path is prevented. In addition to preventing vibrations from the internal combustion engine that is also a vibration source and / or its exhaust path from being transmitted to the metal cover.
Therefore, for example, compared to the case where the metal cover itself resonates with respect to the vibration input from the vibration reduction, the metal cover can be attached with a high vibration damping property.

  Further, since the metal cover is composed of one or a plurality of aluminum alloy plates each having a corrugated shape extending in a direction crossing each other, a metal cover with high deformability can be configured. Therefore, for example, even in the case of an internal combustion engine having a complicated shape and / or its exhaust path, a metal cover having a shape corresponding to the shape can be formed. Further, since metal covers having shapes corresponding to those shapes can be attached, heat dissipation from the internal combustion engine and / or its exhaust path can be more reliably prevented.

  As an aspect of the present invention, the directions intersecting each other are defined as a first direction and a second direction orthogonal to each other, and the corrugated shape includes a raised portion and a trough portion each extending along the first direction. The ridges are alternately repeated in the second direction, and the ridges are alternately arranged with the first erection parts and the second erection parts rising from the valley parts along the first direction, The flat portions and the concave portions are alternately arranged along the first direction, and the first upright portion has a pair of side walls that rise in a substantially inverted trapezoidal shape from the valley portion, and a front end of the side wall is mutually The first upright portion is inwardly curved, and the distal end portion is wider than the proximal end portion of the first upright portion, and the first upright portion is wider. 2 Standing part is a pair of side walls rising from the flat part, and the tip of the side wall Is composed of a sintered the concave recess, said first upright portion and the concave portion, and said second upright portion and the flat portion may be formed so as to be continuous to each intermittently along the second direction.

  With this configuration, since the shape workability of the metal cover is further improved, it is possible to easily form a shape that matches the shape of the internal combustion engine to be attached and / or its exhaust path. Therefore, heat dissipation from the internal combustion engine and / or its exhaust path can be more reliably prevented.

  According to the present invention, it is possible to provide a shock absorber having a stable and excellent vibration damping property and a metal cover to be attached using the shock absorber.

The perspective view of a buffering device. Explanatory drawing of a buffering device. The top view of a shock absorber. The plane direction sectional view of a buffering device. Explanatory drawing of a color member. Explanatory drawing of a spiral spring. Explanatory drawing of a grommet. Sectional drawing about the mounting state of a shock absorber. The schematic front view about the mounting state of a shock absorber. Explanatory drawing about the corrugated board which comprises a heat insulator. The graph which shows the relationship between distortion amplitude and a loss factor. The graph which shows distribution of the damping performance with respect to the temperature of a Fe-Al damping alloy. The graph which shows the characteristic of a shock absorber. The graph which shows the other characteristic of a shock absorber. The graph which shows the further another characteristic of a shock absorber. The graph which shows the further another characteristic of a shock absorber. Sectional drawing about the mounting state of the shock absorber of a prior art. The schematic diagram explaining the buffer principle of a prior art. Graph explaining the first problem of the prior art The graph explaining the 2nd problem of a prior art. The table | surface of the result of an Example and a comparative example.

An embodiment of the present invention will be described with reference to the drawings.
1 is a perspective view of a shock absorber 31 according to the present embodiment, FIG. 2 is an explanatory view of the shock absorber 31, FIG. 3 is a plan view of the shock absorber 31, and FIG. The figure is shown. 2A shows a front view of the shock absorber 31, and FIG. 2B shows a cross-sectional view of the shock absorber 31.

5 shows an explanatory view of the collar member 39, FIG. 6 shows an explanatory view of the spiral spiral spring 32, and FIG. 7 shows an explanatory view of the grommet 33.
5A is a plan view of the collar member 39 of the shock absorber 31, FIG. 5B is a sectional view of the collar member 39, and FIG. 5C is an exploded sectional view of the collar member 39. Show. 6A is a plan view of the spiral spiral spring 32 of the shock absorber 31, FIG. 6B is a front view of the spiral spiral spring 32, and FIG. 6C is a cross section of the spiral spiral spring 32. The figure is shown. 7A shows a plan view of the grommet 33, FIG. 7B shows a cross-sectional view of the grommet 33, and FIG. 7C shows a bottom view of the grommet 33.

  8 shows a sectional view of the mounting state of the shock absorber 31, FIG. 9 shows a schematic front view of the mounting state of the shock absorber 31, and FIG. 10 explains the corrugated sheet 120 constituting the heat insulator 3. The figure is shown.

  10 (a) shows a perspective view of the corrugated sheet 120, FIG. 10 (b) shows an II end view in FIG. 10 (a), and FIG. 10 (c) shows II in FIG. 10 (a). -II end view is shown, and FIG. 10 (d) shows a III-III end view in FIG. 10 (a).

  11 shows a graph showing the relationship between the strain amplitude and the loss coefficient, FIG. 12 shows a graph showing the distribution of the damping performance with respect to the temperature of the Fe—Al damping alloy, and FIG. 13 shows the characteristics of the shock absorber 31. 14 to 16 are graphs showing other characteristics of the shock absorber 31. FIG.

  As described in the background art, an exhaust manifold 1 is attached to a side surface of an engine 2 of a vehicle such as an automobile in order to discharge combustion exhaust gas (see FIG. 9). A heat insulator 3 that covers the exhaust manifold 1 is attached to the exhaust manifold 1. About the heat insulator 3 etc., since it is similar to the description in background art, description for the second time is abbreviate | omitted.

  The shock absorber 31 of the present invention is a shock absorber having a floating mount structure for attaching the heat insulator 3 to the exhaust manifold 1, and includes a spiral spiral spring 32, a grommet 33, and a collar member 39 for buffering vibration.

  The collar member 39 has a columnar shape with a low height with respect to the diameter, and is made of an iron-based material such as SPCC. Further, as shown in FIG. 5A, the collar member 39 includes a bolt hole 40 that allows insertion of the mounting bolt 6 in the center in plan view, and a collar member mounting portion of a spiral spiral spring 32 described later on the side surface. A fitting recess 41 that allows the fitting of 32a is provided.

  The collar member 39 is configured by being fitted with a lower collar 39a that protrudes downward and an upper collar 39b. Specifically, the lower collar 39a includes an annular flange portion 39aa provided with a circumferential circumferential groove 41a on the outer diameter side of the upper surface, and a cylindrical web portion 39ab protruding upward from the inner peripheral edge of the flange portion 39aa. Are integrally formed.

  The upper collar 39b has an annular shape provided with a circumferential circumferential groove 41b on the outer side corresponding to the circumferential groove 41a on the bottom surface and a fitting opening 39ba that allows the above-described web portion 39ab to be fitted on the inner circumferential portion. It is formed in a disk shape. The circumferential grooves 41a and 41b are formed with a depth slightly larger than the cross-sectional radius of a spiral spiral spring 32 described later.

  The lower collar 39a and the upper collar 39b configured in this manner are opposed to the top surface of the flange portion 39aa and the bottom surface of the upper collar 39b, and the web portion 39ab inserted into the fitting opening 39ba is caulked outward in the radial direction. Thus, the lower collar 39a and the upper collar 39b are integrated. At this time, the circumferential groove 41a of the lower collar 39a and the circumferential groove 41b of the upper collar 39b are circumferentially fitted in a concave shape from the side surface of the columnar collar member 39 toward the radially inner side. A joint recess 41 is formed. The fitting recess 41 is configured to face the circumferential grooves 41 a and 41 b having a depth slightly deeper than the cross-sectional radius of the spiral spiral spring 32, so that the fitting recess 41 is slightly higher than the cross-sectional diameter of the spiral spiral spring 32. A concave portion having a high circumferential shape in a plan view is formed.

  The spiral spiral spring 32 is formed of a spiral circular cross-section wire, and includes a collar member mounting portion 32a that allows the collar member 39 to be mounted at the central portion in the radial direction of the spiral shape, and a connecting portion 38 of a grommet 33 described later. The to-be-held part 32b hold | maintained is provided in the radial direction outer side part in a spiral shape.

  Specifically, the spiral spiral spring 32 gradually changes in the height direction (vertical direction in FIG. 6B) along the spiral direction, and a pitch angle as shown in the enlarged cross-sectional view of the part e in FIG. P is formed in a spiral spiral shape of 5 degrees. Note that the pitch angle P is an arrangement angle of the spiral wire relative to the horizontal plane. As shown in FIG. 6B, the spiral spiral spring 32 is formed in a spiral spiral shape of four turns in which the held portion 32b on the outer diameter side is higher than the collar member mounting portion 32a on the inner diameter side.

  Further, as described above, the spiral spiral spring 32 includes the arcuate collar member mounting portion 32a in the spiral spiral radial center portion and the arc-shaped held portion 32b in the spiral spiral radial outer portion. It has.

  The collar member mounting portion 32a and the held portion 32b are formed in a circular arc shape with the same diameter at a central angle r of 270 degrees, which is 3/4 circle from the end (see FIG. 6A). The inner circumferential circle of the collar member mounting portion 32a is formed with a diameter slightly larger than the inner circle 41c of the fitting recess 41 in the collar member 39 described above. Specifically, it is formed with a diameter about 0.2 mm larger. Therefore, a gap s is formed between the inner periphery of the collar member mounting portion 32a and the inner circle 41c of the fitting recess 41 (see FIG. 2 (b) a portion enlarged view and FIG. 4c portion enlarged view).

  In addition, the spiral spiral spring 32 plastically processes an alloy composed of Al content of 2 to 12% by weight, the balance Fe and unavoidable impurities, cold-rolls the plastic-processed alloy, and performs the cold-rolled alloy. It is made of a wire rod made of Fe-Al damping alloy having a spring property that is manufactured so as to have an average crystal grain size of 250 μm or less by annealing.

  In addition, the spiral spiral spring 32 is configured in a spiral spiral shape of four turns with a circular cross-section wire, but according to various usage conditions such as the frequency band and amplitude of vibration to be suppressed, the temperature under use, It may be composed of other optional cross-section wire having a closed curved surface, and may be appropriately selected along with the diameter, material, or number of turns of the wire.

  The grommet 9 includes a first holding part 36 that holds the heat insulator 3, a second holding part 37 that holds the spiral spiral spring 32, and a connecting part 38 that connects the first holding part 36 and the second holding part 37. And has an insertion hole 35 in the center in plan view, and is formed in an annular shape having a substantially S-shaped section.

  Specifically, the first holding portion 36 that holds the heat insulator 3 on the outer diameter side has a predetermined radial length portion from the outer peripheral edge to the inner peripheral side of the annular metal plate from the upper side to the lower side in FIG. Folded from the radially inner periphery side to the outer periphery side, it is formed in a J-shape that is inverted radially outward. In addition, the 1st holding | maintenance part 36 is formed with the thickness which pinches | interposes the heat insulator 3 mentioned later.

  Further, the second holding portion 37 that holds the spiral spiral spring 32 on the inner diameter side has a predetermined radial length portion from the inner peripheral edge to the outer peripheral side of the annular metal plate from the lower side to the upper side in FIG. It is folded from the outer peripheral side to the inner peripheral side and formed into a J-shape that is inverted inwardly in the diameter. In addition, the 2nd holding | maintenance part 37 is formed in the thickness which pinches | interposes the above-mentioned spiral spiral spring 32. FIG. Further, a slight gap s is formed between the outer circumference of the held portion 32b of the spiral spiral spring 32 and the inside of the inverted J-shaped second holding portion 37 (FIG. 2B). Part enlarged view, see FIG. 4d part enlarged view).

  The connecting portion 38 is bent over the first holding portion 36 and the second holding portion 37, and is formed at the lower end on the inner side of the first holding portion 36 formed in a J-shape that is radially outwardly inverted. It is the structure which connects a part mutually. The second holding portion 37, the connecting portion 38, and the first holding portion 36 are arranged in this order from the bolt boss 34 provided on the exhaust manifold 1.

  As described above, the shock absorber 31 is configured by assembling the collar member 39, the spiral spiral spring 32, and the grommet 33 configured as described above. Specifically, the collar member 39 and the spiral spiral spring 32 are assembled by fitting the collar member mounting portion 32 a of the spiral spiral spring 32 into the fitting recess 41 of the collar member 39. At this time, as described above, a gap s is provided between the inner circle 41c of the fitting recess 41 and the inner peripheral side of the collar member mounting portion 32a of the spiral spiral spring 32, and the collar member mounting portion 32a A range of 3/4 can be wound around the circumferential surface of the circle 41c (see FIG. 4).

  Further, the grommet 33 and the spiral spiral spring 32 are assembled by fitting the held portion 32 b of the spiral spiral spring 32 to the second holding portion 37 of the grommet 33. At this time, as described above, a gap s is provided between the inner peripheral surface of the second holding portion 37 of the grommet 33 and the outer periphery of the held portion 32b of the spiral spiral spring 32, and the held portion 32b is It arrange | positions in the range of 3/4 with respect to the internal peripheral surface of the 2nd holding | maintenance part 37 (refer FIG. 4).

  Further, as shown in FIG. 2B, the spiral spring 32 is disposed between the shock absorber 31 and the collar member 39 so that the held portion 32b on the outer diameter side is higher than the collar member mounting portion 32a on the inner diameter side. Therefore, in the collar member 39 that fits the collar member mounting portion 32a in the fitting recess 41, the second holding portion 37 that holds the held portion 32b is at a high position (upward in FIG. 2B). Assembled.

  As shown in FIG. 8, the shock absorber 31 configured in this manner is mounted in a mounting hole 3 a formed in the heat insulator 3, and is attached by a mounting bolt 6 screwed into a bolt boss 34 formed in the exhaust manifold 1. The bolt boss 34 is fixed.

  As shown in FIG. 9, the heat insulator 3 is formed so as to cover the exhaust manifold 1 attached to the side surface of the engine 2, and the shock absorber 31 against the plurality of bolt bosses 34 provided on the exhaust manifold 1. And is fixed by the mounting bolt 6.

  In this way, the heat insulator 3 having a shape covering the exhaust manifold 1 has been made of an aluminum-plated steel plate in the past. However, in recent years, a corrugated sheet 120 made of light metal obtained by corrugating aluminum in two directions intersecting each other is used. It is used after being processed into a predetermined shape (see FIG. 10).

  Specifically, in the corrugated sheet 120, as shown in FIGS. 10B and 10C, the ridges 121 and the valleys 122 are alternately and continuously connected in the X direction, and the ridges 121 in the Y direction. As shown in FIG. 10 (d), the corrugated aluminum plate is formed by repeating the top (121a, 122a) and the bottom (121b, 122b) at regular intervals. is there.

The raised portion 121 and the valley portion 122 form the corrugated shape by alternately repeating wide and narrow at regular intervals at regular intervals in the X direction.
More specifically, in the corrugated shape of the corrugated sheet 120, the ridges 121 and the valleys 122 each extending along the Y direction are alternately repeated in the X direction.

  The ridges 121 are alternately arranged with the tops 121a and the bottoms 121b rising from the valleys 122 along the Y direction, and the valleys 122 are the tops of the flats 122a and the bottoms along the Y direction. The recesses 122b are alternately arranged.

  The top part 121a is composed of a pair of side walls that rise in a substantially inverted trapezoidal shape from the valley part 122, and a relatively flat top part that is formed by connecting the tips of the side walls to each other. The tip end portion is wider than the base end portion of the top 121a.

  The bottom part 121b is composed of a pair of side walls rising from the flat part 122a, and a concave concave part 122b in which the tips of the side walls are connected to each other. The top part 121a and the concave part 122b, and the bottom part 121b and the flat part 122a are arranged in the X direction. Are formed so as to be intermittently connected to each other.

  In the heat insulator 3 in which the corrugated sheet 120 is processed into a predetermined shape, the mounting hole 3a is formed at a location corresponding to the bolt boss 34 provided in the exhaust manifold 1, and the corrugated shape around the mounting hole 3a is crushed. The crushing portion 3b formed in a substantially flat plate shape is held by the first holding portion 36.

  Further, the heat insulator 3 formed in a three-dimensional shape is defined in a direction in which any one of the corrugated shapes intersecting with each other intersects with a main ridge line corresponding portion constituting the three-dimensional shape.

  More specifically, since the heat insulator 3 is formed into a three-dimensional shape that conforms to the three-dimensional appearance of the exhaust manifold 1 as described above, the heat insulator 3 has one or more ridge line corresponding portions that are bent portions. It is formed. In the present embodiment, the corrugated shape is pressed into a three-dimensional shape so that the longitudinal direction of the corrugated shape intersects the main ridge line equivalent portion of the plurality of ridge line equivalent portions.

  Here, the main ridge line equivalent part is a part where a bent part having a relatively large curvature characterizing the overall shape of the heat insulator 3 continues. That is, among the various bent portions formed on the heat insulator 3, the bent portion extends over a relatively long length that substantially determines the external shape of the heat insulator 3.

  When the heat insulator 3 is attached to the exhaust manifold 1, the heat insulator 3 also vibrates due to the transmission of vibration from the exhaust manifold 1. When the heat insulator 3 vibrates due to this vibration, the portions of the heat insulator 3 on both sides of the portion corresponding to the main ridge line are vibrated greatly like butterfly wings. When such vibration is generated, a portion near the ridge line portion of the heat insulator 3 is subject to metal fatigue due to repeated bending, and cracks are likely to occur.

  On the other hand, the heat insulator 3 according to the present embodiment is such that one direction of the corrugated shape formed in the heat insulator 3 intersects the main ridge line corresponding portion, and is preferably orthogonal. Therefore, the corrugated shape realizes the action of the rib against the vibration centered on the ridge line corresponding portion. Thereby, the vibration of the heat insulator 3 can be suppressed, the occurrence of cracks in the heat insulator 3 can be prevented, and the quality of the heat insulator 3 can be significantly improved.

  By configuring in this way, the heat insulator 3 is, as shown in FIG. 8, a bolt boss provided in the exhaust manifold 1 via a shock absorber 31 mounted in a mounting hole 3a formed in the heat insulator 3. 34 can be fixed.

  As described above, the shock absorber 31 is disposed between the bolt boss 34 provided on the exhaust manifold 1 that is a vibration source and the heat insulator 3 that is the connection target, and the bolt boss 34 provided on the exhaust manifold 1 and the heat insulator. 3, and a device for buffering vibration transmission from the bolt bosses 34 provided on the exhaust manifold 1 to the heat insulator 3. As described above, the shock absorber 31 is stable and excellent. It can exhibit vibration damping properties.

  Specifically, the shock absorber 31 includes a spiral spiral spring 32 that cushions vibration, a grommet 33 that couples the spiral spiral spring 32 and the heat insulator 3, and a mounting bolt 6 and a spiral that are fastened to a bolt boss 34 provided on the exhaust manifold 1. The collar member 39 is interposed between the spiral spring 32.

  The grommet 33 surrounds the spiral spiral spring 32, holds the heat insulator 3 on the radially outer side, a second holding portion 37 that holds the spiral spiral spring 32 on the radially inner side, The first holding unit 36 and the second holding unit 37 are connected to each other.

  In addition, the spiral spiral spring 32 is formed of a spiral wire, and a collar member mounting portion 32a that allows the mounting of the collar member 39 is provided at the central portion in the radial direction of the spiral shape and is held by the second holding portion 37. The held portion 32b is provided on the radially outer side of the spiral shape.

  Further, the collar member 39 is provided with a bolt hole 40 that allows the attachment bolt 6 to be inserted on the inside of the diameter, and is provided with a fitting recess 41 that holds the collar member mounting portion 32a on the outside of the diameter.

  As described above, the spiral spiral spring 32 is formed of a spiral wire, and the collar member mounting portion 32a that allows the mounting of the collar member 39 is provided in the central portion in the radial direction in the spiral shape, and the collar member mounting portion 32a is provided. Since the holding concave portion 41 to be held is provided on the outer side of the collar member 39, the spiral spiral spring 32 composed of a spiral wire rod performs a bending motion by the vibration transmitted from the collar member 39 to the spiral spiral spring 32.

  By such a bending motion, the shock absorber 31 can convert the vibration energy of the vibration transmitted from the collar member 39 into the bending kinetic energy of the spiral spiral spring 32 and suppress the vibration transmitted to the heat insulator 3. .

  In addition, the collar member mounting portion 32a that allows the mounting of the collar member 39 is provided in the spiral central portion in the radial direction, and the fitting recess 41 that holds the collar member mounting portion 32a is provided outside the diameter of the collar member 39. Transmission of vibration can be suppressed without causing the spiral spiral spring 32 and the collar member 39 to collide with each other. Therefore, the transmission of vibration from the collar member 39 to the spiral spiral spring 32 is suppressed without generating a rattling noise caused by the collision between the spiral spiral spring 32 and the collar member 39 as in the above-described conventional shock absorber 5. In other words, excellent vibration damping can be achieved.

  Specifically, as shown in FIG. 17, the conventional shock absorber 5 is formed of an annular buffer member 8 formed by knitting metal fibers in a mesh shape and forming it into a flat mat shape, and an aluminum alloy. The grommet 9 is a coupling member having a substantially S-shaped cross section, and a collar member 10 disposed between the buffer member 8 and the mounting bolt 6.

The collar member 10 is disposed between the annular buffer member 8 and the mounting bolt 6 that is screwed onto the mounting boss 18.
The collar member 10 includes a cylindrical portion 14 and flange portions 15 and 16 integrally formed at both ends in the axial direction of the cylindrical portion 14. The collar member 10 includes a mounting bolt 6 between the collar member 10 and the buffer member 8. A gap 17 in the axial direction and the radial direction is formed.

  The heat insulator 3 to which the shock absorber 5 is attached via the grommet 9 is disposed on the exhaust manifold 1 so that the shock absorber 5 is located at a position corresponding to the mounting boss 18 of the exhaust manifold 1. Then, the heat insulator 3 can be attached to the exhaust manifold 1 via the shock absorber 5 by screwing the attachment bolt 6 to the attachment boss 18.

  In this prior art shock absorber 5, since the gap 17 is provided, the shock absorber 8 vibrates in the collar member 10. The principle will be described with reference to the schematic diagram shown in FIG.

  First, a vibrating object including the collar member 10 to which vibration from the exhaust manifold 1 is directly transmitted is defined as a collision object m in FIG. For the vibration of the collision body m, a resistance element k related to vibration and a leveling element c corresponding to an electrical capacitor are set.

  The shock-absorbing member 8 on which the collar member 10 collides due to vibration is assumed to be a collision target in FIG. Such a modelization can realize the formulation of the vibration phenomenon.

  In the above configuration, the vibration that is input from the exhaust manifold 1 and transmitted from the collar member 10 to the buffer member 8 can be suppressed by the gap 17 described above. Further, the buffer member 8 itself bends by the vibration transmitted from the collar member 10 to the buffer member 8.

  As described above, the shock absorber 5 can convert the vibration energy of the vibration transmitted from the collar member 10 into the bending kinetic energy of the buffer member 8 and suppress the vibration transmitted to the heat insulator 3.

  In addition, the buffer device 5 of the prior art reduces the contact between the buffer member 8 and the collar member 10 by providing the gap 17, and reduces the fiber diameter of the buffer member 8 made of metal fiber. The heat transfer area related to heat transfer from the collar member 10 to the buffer member 8 is reduced. Further, heat dissipation from the buffer member 8 due to an increase in the surface area of the buffer member 8 is promoted. Therefore, the amount of heat transfer from the exhaust manifold 1 to the heat insulator 3 is reduced through the collar member 10 and the buffer member 8.

  Further, the buffer member 8 vibrates in the collar member 10 due to the gap 17. The vibration of the buffer member 8 can prevent the buffer member 8 from always contacting the collar member 10. Therefore, the amount of heat transferred from the collar member 10 to the buffer member 8 and the amount of heat transferred from the exhaust manifold 1 to the heat insulator 3 via the collar member 10 and the buffer member 8 can be reduced.

  However, the vibration of the buffer member 8 within the collar member 10 means that the buffer member 8 collides with the collar member 10. Therefore, there is a risk that a rattling noise is generated due to the collision between the buffer member 8 and the collar member 10 due to the vibration. As an example, this noise has a considerably high sound pressure in an audible frequency band of 150 Hz or less, and its vibration damping property is insufficient.

  In addition, the buffer member 8 is configured by forming metal fibers in a mesh shape in a knitted mat shape, but the cutting dimension of the metal fibers to a predetermined fiber length is likely to vary, and the elasticity of the buffer member 8 is varied. There is a possibility that the buffering performance of the shock absorber 5, that is, the vibration damping performance of the shock absorber 5 may vary. This phenomenon was confirmed by the graph of FIG. 19 showing the measurement result of the present inventors that the dimensional variation affects the tensile strength.

  Furthermore, since the elasticity of the buffer member 8 is also affected when the hole size of the annular buffer member 8 varies, the buffer performance of the buffer device 5 may vary. This phenomenon was confirmed by the fact that the dimensional variation affects the tensile strength by the graph of FIG. 20 showing the same measurement result of the present inventors. Therefore, there is a possibility that the damping property of the shock absorber 5 becomes unstable.

  Further, as described above, the buffer member 8 knits metal fibers in a mesh shape, which is performed by knitting. Next, the buffer member 8 is produced by processing into an annular shape. In each of the knitting process and the annular process, a great deal of time is required for the process.

  On the other hand, in the shock absorber 31, the spiral spiral spring 32 corresponding to the shock absorber 8 of the shock absorber 5 of the prior art is composed of a spiral wire, so that the metal fibers are knitted into a mesh shape and formed into a mat shape. Compared to the cushioning member 8 (see FIG. 14), the product has less variation. Therefore, the spiral spiral spring 32 with stable elasticity can be configured. Therefore, it is possible to configure the shock absorber 31 having stable vibration damping properties.

  Further, since the spiral spiral spring 32 is composed of a wire shaped into a spiral shape, it is not necessary to handle fine inorganic fibers, and the fiber length is managed in the process of cutting the inorganic fibers into a predetermined fiber length, or the final product. This eliminates the difficulty in managing the dimensional accuracy with high accuracy in the machining process. Thereby, dimensional accuracy is improved, and the accuracy and stability of the damping performance of the shock absorber 31 can be improved.

  Therefore, by setting the shock absorber 31 as described above, the bolt boss 34 and the heat insulator 3 provided on the exhaust manifold 1 serving as the vibration source can be coupled without transmitting vibration.

  The heat input from the collar member 39 is transmitted to the grommet 33 and the heat insulator 3 via the spiral spiral spring 32. However, since the spiral spiral spring 32 is formed of a spiral spiral wire, Therefore, heat conduction to the grommet 33 and the heat insulator 3 via the spiral spiral spring 32 can be suppressed.

  Further, the spiral spiral spring 32 is formed in a spiral spiral shape that gradually changes in the height direction along the spiral direction, and the held portion 32b is mounted on the collar boss 34 on the bolt boss 34 provided on the exhaust manifold 1. Since it arrange | positions in the direction away from the part 32a, the damping property in the buffer device 31 can be improved.

  Specifically, by forming the spiral spiral spring 32 in a spiral spiral shape, the elastic force in the height direction can be adjusted in addition to the elasticity in the planar direction. That is, the elasticity of the spiral spiral spring 32 that greatly affects the vibration damping performance of the spiral spiral spring 32 can be adjusted in three dimensions.

  Further, by arranging the spiral spiral spring 32 in a direction in which the held portion 32b is separated from the collar member mounting portion 32a with respect to the bolt boss 34 provided on the exhaust manifold 1, the inner diameter of the spiral spiral spring 32 is increased. From the collar member mounting portion 32 a, the held portion 32 b outside the diameter is separated from the bolt boss 34 provided on the exhaust manifold 1.

  That is, the heat insulator 3 held by the first holding portion 36 of the grommet 33 holding the held portion 32b by the second holding portion 37 is provided in the exhaust manifold 1 from the collar member 39 wound around the collar member mounting portion 32a. It will be arranged away from the bolt boss 34.

Therefore, even if the heat insulator 3 itself vibrates due to the vibration transmitted through the collar member 39 and the spiral spiral spring 32, the collar member 39 is removed from the bolt boss 34 provided on the exhaust manifold 1 by the heat insulator 3. Compared to a case where the heat insulator 3 is disposed apart from the heat insulator 3, the possibility that the heat insulator 3 itself collides with the bolt boss 34 provided in the exhaust manifold 1 can be reduced. Therefore, the generation of noise due to the collision between the heat insulator 3 itself and the bolt boss 34 provided on the exhaust manifold 1 can be suppressed.
Thus, by setting the shock absorber 31 to the above-described configuration, it is possible to further improve the vibration damping performance without causing new vibration due to the collision.

  Further, by forming the spiral spiral pitch angle P at 5 degrees or less, it is possible to configure the shock absorber 31 having appropriate elasticity in the three-dimensional direction. Specifically, when the pitch angle P is set large, the height of the spiral spiral increases, and the elastic force in the height direction can be improved.

  On the other hand, the elasticity in the horizontal direction is reduced. That is, the balance of elasticity in the three-dimensional direction of the spiral spiral spring 32 is lost, blurring increases in the elastic support state, and a sufficient vibration damping effect cannot be obtained. Therefore, by forming the spiral spiral pitch angle P at 5 degrees or less, the effect of forming the spiral spiral spring 32 as described above is achieved while maintaining the balance of elasticity in the three-dimensional direction. A sufficient damping effect can be obtained.

  In addition, the collar member mounting portion 32a and the held portion 32b are formed in an arc shape, and by forming the fitting concave portion 41 that allows the collar member mounting portion 32a to be fitted on the cylindrical side surface, the spiral spiral can be easily formed. The spring 32 and the collar member 39 can be fitted together, and the held portion 32 b can be held by the second holding portion 37.

  Specifically, in order to form the collar member mounting portion 32a and the held portion 32b in an arc shape and to form the fitting recess 41 that allows the collar member mounting portion 32a to be fitted on the side surface of the cylindrical collar member 39, The collar member mounting portion 32a formed in an arc shape is fitted into the fitting recess 41 on the side surface of the collar member 39 formed in a cylindrical shape, so that the spiral spiral spring 32 and the collar member 39 are easily fitted. Can do.

Further, since the collar member mounting portion 32a formed in an arc shape and the fitting recess 41 formed in the cylindrical side surface are fitted, the spiral spiral spring 32 can be easily formed regardless of the circumferential position with respect to the collar member 39. And the collar member 39 can be fitted.
Further, since the held portion 32b is formed in an arc shape, it can be held by the second holding portion 37 regardless of the position in the circumferential direction.

  As described above, since the spiral spiral spring 32 and the collar member 39 can be easily fitted and the held portion 32b can be held by the second holding portion 37, the assembling property of the shock absorber 31 can be improved. it can.

  Further, for example, the collar member mounting portion 32a formed in an arc shape is formed in a cylindrical shape as compared with the case where the collar member mounting portion 32a of the spiral spiral spring 32 is mounted on the collar member 39 using another member. By fitting into the fitting recess 41 on the side surface of the formed collar member 39, the number of parts can be reduced. Therefore, weight reduction and cost reduction of the shock absorber 31 can be achieved.

  Further, by providing the gap s between the fitting recess 41 and the collar member mounting portion 32a and between the second holding portion 37 and the held portion 32b, the vibration damping performance in the shock absorber 31 can be further improved. it can. Specifically, since the gap s is formed in a state where the collar member mounting portion 32a and the held portion 32b formed in an arc shape are held by the fitting concave portion 41 and the second holding portion 37, the color member mounting portion 32a The vibration input through the collar member 39 can be absorbed by the gap s without causing a collision sound in the fitting recess 41, the held portion 32 b and the second holding portion 37.

  In addition, by forming the collar member mounting portion 32a and the held portion 32b in an arc shape of 270 degrees with a central angle of 240 degrees or more and 300 degrees or less, the product reliability of the shock absorber 31 having high vibration damping is improved. can do.

  Specifically, the color member mounting portion 32a and the held portion 32b are formed in an arc shape with a central angle of 240 degrees or more and 300 degrees or less, thereby forming the color member mounting portion 32a and the held portion 32b formed in an arc shape. It is possible to prevent the fitting recess 41 and the second holding portion 37 from being inadvertently detached while being held while providing the gap s.

  Specifically, when the center angle of the collar member mounting portion 32a is smaller than 240 degrees, the restraining force that the collar member mounting portion 32a restrains the inner circle 41c of the collar member 39 is reduced, and the collar member 39 and the spiral spiral spring are reduced. 32 may accidentally come off. Further, when the center angle of the collar member mounting portion 32a is larger than 300 degrees, a sufficient pitch angle P in the spiral spiral shape cannot be secured. As described above, the collar member mounting portion 32a is formed in an arc shape having a central angle of 240 degrees or more and 300 degrees or less, thereby ensuring a sufficient mounting strength and a spiral spiral spiral having a predetermined pitch angle P. A spiral spring 32 can be formed. Therefore, stable vibration control can be ensured.

  Further, the spiral spiral spring 32 is plastically processed with an alloy containing Al content of 2 to 12% by weight, the remainder Fe and unavoidable impurities, and the plastic processed alloy is cold-rolled, and the alloy after the cold-rolling is processed. By constituting the wire rod made of a Fe-Al damping alloy having spring properties manufactured so that the average crystal grain size is 250 μm or less by annealing, the shock absorber 31 having higher damping property can be easily processed. can do.

  Specifically, since the spiral spiral spring 32 is made of an Fe—Al damping alloy having a vibration damping coefficient that is significantly larger than that of the conventional damping metal, the vibration transmitted from the collar member 39 to the spiral spiral spring 32 is: The amplitude can be attenuated based on the large vibration damping coefficient of the Fe—Al damping alloy itself. Thereby, a great damping action can be realized by the damping alloy itself.

  Usually, stainless spring steel such as SUS304 is used for a portion requiring springiness, such as the spiral spring described above. However, when SUS304 is heated to around 350 ° C., it tends to cause stress corrosion cracking. If the spiral spiral spring 32 is easily cracked, the heat insulator may fall off the exhaust manifold 1 in the engine room of the vehicle.

  On the other hand, the Fe—Al damping alloy constituting the spiral spiral spring 32 of this embodiment has a high damping coefficient and can maintain mechanical strength even in a relatively high temperature range. By using a vibration alloy, as will be described later, it is possible to achieve a vibration damping action that is significantly greater than that of conventional vibration damping metals.

In addition, the effect confirmation test for confirming that the Fe-Al damping alloy which consists of the said unique composition is excellent in workability is demonstrated below.
First, pure iron and 99.9% by weight of Al were weighed in a predetermined amount so that the Al content would be 8% by weight and dissolved in a high frequency vacuum (final composition; Al; 7.78% by weight, C; 004 wt%, Si: 0.02 wt%, Mn: 0.05 wt%, P: 0.005 wt%, S: 0.002 wt%, Cr: 0.02 wt%, Ni: 0.05 wt% %, And Fe: balance).

  After melting, hot working was performed at 1100 ° C. to 200 × 100 × 4000 mm, a part was cut out from this, and further hot rolled at 1100 ° C. to a thickness of 4 mm. Next, after annealing at 700 ° C. for 1 hour, it was air-cooled to room temperature. Cold-rolling was performed on each Fe-Al vibration-damped alloy after cooling under each processing condition that the cross-sectional reduction rate was 50% at 20 ° C. Next, after annealing at 800 ° C. for 1 hour, the product was cooled to 600 ° C. at a cooling rate of 1 ° C./min and air-cooled.

  Using the Fe—Al damping alloy thus obtained, high-speed processing was performed at 200 ° C. to form a frying pan. As a result, it was possible to easily process into a frying pan without inconvenience such as cracking. On the other hand, when Fe-Al damping alloy (thickness 2 mm) prepared with the same composition as above and not cold-worked was processed at high speed under the same conditions and formed into a frying pan shape, The product cracked.

  Further, the Fe-Al damping alloy obtained in this way was pulled until it was crushed with a tensile tester under a temperature condition of 200 ° C., and the crushed cross section was observed with a microscope. Existence was observed. From this, it was confirmed that the above-described Fe—Al vibration-damping alloy is excellent in workability and can be strongly processed in warm processing at about 200 ° C.

  Next, a strength confirmation test for confirming the strength of the Fe—Al damping alloy prepared by the above method will be described. In this confirmation test, in order to evaluate the strength of the Fe—Al damping alloy, the tensile strength and elongation were measured using an Instron Digital Universal Material Testing Machine (model 5582, manufactured by Instron) at −30. Tensile strength and elongation under temperature conditions of ° C, 26 ° C and 160 ° C were measured (n = 2).

  Further, as Comparative Example 1, this strength was obtained except that annealing was performed at 900 ° C. for 1 hour without performing cold rolling, cooling to 500 ° C. at 1 ° C./min, and then allowing to cool to room temperature. A Fe—Al damping alloy was produced in the same manner as in the measurement. The tensile strength and elongation at 26 ° C. of the Fe—Al damping alloy during this strength measurement were measured.

  The obtained results are shown in the table of FIG. From this result, it was confirmed that the present Fe—Al damping alloy showed high tensile strength even under a wide range of temperatures from −30 to 160 ° C. and had excellent strength. In particular, the present Fe—Al damping alloy was confirmed to be significantly superior in elongation to the alloy of Comparative Example 1.

  Subsequently, the cooling rate after the annealing after the cold working is 5 ° C./min (cooling condition 1) or 1 ° C./min (cooling condition 2), except that the cooling rate is as described above, except that the cooling rate is as described above. A vibration damping confirmation test for confirming the vibration damping property of the prepared Fe—Al damping alloy will be described.

  In this confirmation test, for comparison, the same composition as that of the Fe-Al vibration-damping alloy, which was manufactured by annealing at 900 ° C. for 1 hour after hot rolling and furnace cooling. The vibration damping performance of the -Al damping alloy (comparative alloy) was similarly evaluated.

  The vibration damping was evaluated using the lateral vibration method. Specifically, a strain gauge was bonded to one end (130 mm from the end) of the Fe—Al damping alloy sheet (0.8 × 30 × 300 mm) and connected to a strain gauge. The other end of the Fe-Al damping alloy sheet is fixed with a vise, and a free length is generated as a cantilever with a free length of 150 mm, strain is detected from the strain gauge, and a strain attenuation curve is obtained. It was. In addition, an accelerometer was attached, and a decay curve from acceleration was obtained.

  The obtained results are shown in FIG. From this result, it was confirmed that the slower the cooling rate after annealing, the better the damping characteristics. In addition, the Fe—Al damping alloy of the present invention has excellent damping characteristics compared to an Fe—Al damping alloy (comparative alloy) annealed at 900 ° C. without cold rolling. It was confirmed.

  Further, it is known that this Fe—Al damping alloy has a vibration damping coefficient much higher than that of a conventional damping metal. Therefore, the amplitude of the vibration transmitted from the collar member 39 to the spiral spiral spring 32 is attenuated based on the large vibration damping coefficient of the damping alloy itself. Thereby, a great damping action can be realized by the damping alloy itself.

  Thus, it is possible to manufacture a spiral spiral spring 32 by forming a wire from an Fe-Al vibration damping alloy having excellent workability, insulation, magnetic permeability, vibration damping, high strength, and the like. In addition, the shock absorber 31 having excellent vibration damping properties can be realized.

  In the following, regarding the vibration damping performance in the shock absorber 31 provided with the spiral spiral spring 32 made of Fe-Al damping alloy having excellent workability, insulation, permeability, vibration damping, high strength and the like as described above. This will be described with reference to FIGS.

The vibration damping performance in the shock absorber 31 of the present embodiment is expressed by the following formula 1. Where τ: shear stress, T: torsional moment, d: wire diameter of the spiral spiral spring 32, G: transverse elastic modulus, L: length in the axial direction of the spiral spiral spring 32.
τ = 16T / πd3 = φdG / 2L (1)
Further, as can be seen from FIG. 12 which shows the result of measuring the temperature-damping characteristics of the spiral spiral spring 32 in this example, the Fe-Al damping alloy of this example does not have a damping characteristic even if the ambient temperature rises. It shows almost the same level without showing a big decrease.

  Further, various conditions relating to vibration damping required by each of the Japanese automobile manufacturers A, B, C, D, and E are shown in FIG. 13 to FIG. It is shown in the distribution map of the correlation with the quantity. In the correlation between the engine speed and the amount of vibration displacement in FIGS. 13 to 16, the condition distribution position of company A is indicated by a white diamond symbol, the condition distribution position of company B is indicated by a white triangle symbol, and the condition of company C The distribution position is indicated by an upper white triangle symbol, the condition distribution position of company D is indicated by a lower white triangle symbol, and the condition distribution position of company E is indicated by a white circle symbol.

  As shown in FIG. 13 to FIG. 16, any automobile manufacturer is expected to have a high vibration damping performance at a speed of about 6000 rpm even at a high engine speed of 2000 to 4000 rpm. It is understood that

  Further, since the spiral spiral spring 32 is formed by spirally forming a wire made of Fe-Al damping alloy, the need to handle fine inorganic fibers as described in the background art is eliminated, and the inorganic fibers are Difficulties in managing the fiber length in the process of cutting to a predetermined fiber length and in managing the dimensional accuracy in the processing step in processing to the final product are eliminated. As a result, the dimensional accuracy is improved, and the accuracy and stability of damping performance of the shock absorber 31 can be improved.

  Furthermore, the spiral spiral spring 32 formed of the Fe—Al damping alloy has a significantly larger vibration damping coefficient than the conventional damping metal, and thus the spiral spiral from the collar member 39. The amplitude of the vibration transmitted to the spring 32 is attenuated based on the large vibration damping performance of the damping alloy itself. Thereby, a great damping action can be realized by the damping alloy itself.

  As described above, the corrugated shapes that extend in the directions intersecting each other are formed using the shock absorber 31 that can improve the vibration damping performance and can stabilize the vibration damping performance without variation. The heat insulator 3 made of one or a plurality of aluminum alloy plates and having a three-dimensional shape is attached to the bolt boss 34 of the exhaust manifold 1 as a vibration source, thereby suppressing heat dissipation and vibration transmission. The heat insulator 3 which can be comprised can be comprised.

  Specifically, the corrugated shape is crushed to form a substantially flattened crushing portion 3b, and one of the directions intersecting each other is determined to intersect with the main ridge line corresponding portion constituting the three-dimensional shape. The heat crushing portion 3b of the heat insulator 3 is held by the first holding portion 36 and attached to the bolt boss 34 by the shock absorber 31 to dissipate heat and transmit vibration from the engine 2 and the exhaust manifold 1 such as an automobile. The heat insulator 3 which can suppress this can be configured.

  In addition, since the heat insulator 3 is attached by the above-described shock absorber 31 having high vibration damping properties, heat dissipation from the engine 2 and the exhaust manifold 1 that is a heat source is prevented, and also from the engine 2 and the exhaust manifold 1 that is also a vibration source. It is possible to prevent vibration from being transmitted to the heat insulator 3.

  Therefore, for example, the heat insulator 3 can be attached in a state of high vibration damping as compared with the case where the heat insulator 3 itself resonates with respect to the vibration input from the vibration reduction.

  Moreover, since the heat insulator 3 is composed of one or a plurality of aluminum alloy plates each having a corrugated shape extending in a direction intersecting each other, the heat insulator 3 having high deformability can be configured. Therefore, for example, even in the case of the engine 2 and the exhaust manifold 1 having complicated shapes, the heat insulator 3 having a shape corresponding to those shapes can be formed. Moreover, since the heat insulator 3 having a shape corresponding to those shapes can be attached, heat dissipation from the engine 2 and the exhaust manifold 1 can be more reliably prevented.

  Further, the directions intersecting each other are defined as the Y direction and the X direction orthogonal to each other, and the corrugated shape is alternately raised in the X direction with the ridges 121 and the valleys 122 extending along the Y direction. In the portion 121, the top portion 121a and the bottom portion 121b are alternately arranged from the valley portion 122 along the Y direction, and the valley portion 122 is alternately arranged with the flat portion 122a and the concave portion 122b along the Y direction. The top portion 121a is composed of a pair of side walls that rise in a substantially inverted trapezoidal shape from the valley portion 122, and a relatively flat top portion that is formed by connecting the tips of the side walls to each other. It is inwardly curved, and the tip end part is wider than the base end part of the top part 121a, and the bottom part 121b is a concave shape in which a pair of side walls respectively rising from the flat part 122a and the tip ends of the side walls are connected to each other. The top part 121a and the concave part 122b, and the bottom part 121b and the flat part 122a are formed so as to be intermittently connected along the X direction, thereby further improving the shape workability of the heat insulator 3. be able to. Therefore, it is possible to easily form a shape that matches the shapes of the engine 2 and the exhaust manifold 1 that are to be attached. Therefore, heat dissipation from the engine 2 and the exhaust manifold 1 can be further reliably prevented.

  As a modification of the present embodiment, the collar member 39, the spiral spiral spring 32, the grommet 33, and the heat insulator 3 are made of materials that are close to each other in ionization tendency to prevent the occurrence of electrolytic corrosion. May be. Even with such a configuration, in addition to the same operational effects as those described above, the corrosion resistance of the shock absorber 31 can be improved, and the life of the shock absorber 31 can be extended.

  Specifically, since the collar member 39, the spiral spiral spring 32, the grommet 33, and the heat insulator 3 are made of materials that are close to each other in ionization tendency, corrosion between different metals that occurs between materials that have greatly different ionization tendency, It is possible to prevent so-called electric corrosion. That is, the corrosion resistance of the shock absorber 31 can be improved, and the life of the shock absorber 31 can be extended.

  Accordingly, it is possible to prevent a decrease in function that may affect the vibration damping performance of the shock absorber 31 such as a decrease in holding force of the holding portion due to corrosion or a decrease in the elasticity of the spiral spiral spring 32. Reliability can be improved.

  Moreover, although the shock absorber 31 of the present embodiment has been described in relation to the heat insulator 3 for the exhaust manifold 1 mounted on the engine 2 of the automobile, the present invention is not limited to such an embodiment. For example, the present invention may be applied to attachment of covers for various uses such as an under cover that covers the bottom of the vehicle body. Moreover, it can implement for attachment of covers of various uses other than a motor vehicle.

As described above, in the correspondence between the configuration of the present invention and the above-described embodiment,
The vibration side target member of the present invention corresponds to the bolt boss 34 provided on the exhaust manifold 1,
Similarly,
The connection target member and the metal cover correspond to the heat insulator 3,
The buffer member corresponds to the spiral spiral spring 32,
The coupling member corresponds to the grommet 33,
The fastening member corresponds to the mounting bolt 6,
The fastening member insertion portion corresponds to the bolt hole 40,
The buffer member holding portion and the fitting recess correspond to the fitting recess 41,
The internal combustion engine corresponds to the engine 2,
The exhaust path corresponds to the exhaust manifold 1,
The crushing target part corresponds to the crushing part 3b,
The first direction corresponds to the X direction,
The second direction corresponds to the Y direction,
The first standing portion corresponds to the top 121a,
Although the second upright portion corresponds to the bottom portion 121b, the present invention is not limited to the above-described embodiment.

  For example, in the present embodiment, in the collar member 39, the second holding portion 37, the connecting portion 38, and the first holding portion 36 are arranged in this order from the side of the bolt boss 34 provided on the exhaust manifold 1. You may arrange | position the 1st holding | maintenance part 36, the connection part 38, and the 2nd holding | maintenance part 37 from the side of the boss | hub 34 for bolts provided in this.

  The present invention can be used as a mount having a floating structure for mounting a heat insulator for an exhaust manifold of an automobile.

DESCRIPTION OF SYMBOLS 1 ... Exhaust manifold 2 ... Engine 3 ... Heat insulator 3b ... Crushing part 6 ... Mounting bolt 31 ... Shock absorber 32 ... Spiral spiral spring 32a ... Collar member mounting part 32b ... Held part 33 ... Grommet 34 ... Bolt boss 36 ... No. 1 holding part 37 ... 2nd holding part 38 ... connecting part 39 ... collar member 40 ... bolt hole 41 ... fitting recess 121 ... raised part 122 ... valley part 121a ... top part 121b ... bottom part 122a ... flat part 122b ... recessed part P ... pitch Corner S ... Gap

Claims (10)

It arrange | positions between the vibration side object member which is a vibration source, and the connection object member which is a connection object, and connects the said vibration side object member and the said connection object member, and the said vibration side object member to the said connection object member A shock absorber for buffering vibration transmission of
The cushioning member that cushions the vibration, a coupling member that couples the cushioning member and the connection target member, and a collar member that is interposed between the fastening member fastened to the vibration side target member and the cushioning member. ,
The coupling member;
Enclosing the buffer member;
A first holding portion for holding the connection target member on the outside of the diameter;
A second holding portion for holding the buffer member on the inside of the diameter;
The connecting portion connecting the first holding portion and the second holding portion,
The buffer member is made of a spiral wire,
A collar member mounting portion that allows the collar member to be mounted is provided at a central portion in the radial direction of the spiral shape, and a held portion that is held by the second holding portion is provided at a radially outer portion of the spiral shape. ,
The collar member,
A shock absorber provided with a fastening member insertion portion that allows insertion of the fastening member on a radially inner side and a shock absorbing member holding portion that holds the collar member mounting portion on a radially outer side. The buffer member;
While forming in a spiral spiral shape that gradually changes in the height direction along the spiral direction,
The shock absorber according to claim 1, wherein the held portion is disposed in a direction away from the collar member mounting portion with respect to the vibration side target member. The shock absorber according to claim 2, wherein the spiral spiral pitch angle is 5 degrees or less. The collar member mounting portion and the held portion are formed in an arc shape,
Forming the second holding portion in a circular shape in plan view;
4. The collar member according to claim 1, wherein the collar member is formed in a cylindrical shape, and the buffer member holding portion is formed by a fitting recess that allows fitting of the collar member mounting portion on the cylindrical side surface. The shock absorber described in 1. The shock absorber according to claim 4, wherein a gap is provided between the buffer member holding portion and the collar member mounting portion, and between the second holding portion and the held portion. The shock absorber according to claim 4 or 5, wherein the collar member mounting portion and the held portion are formed in an arc shape having a central angle of 240 degrees to 300 degrees. The buffer member;
An average grain size is obtained by plastic working an alloy comprising Al content of 2 to 12% by weight, the balance Fe and unavoidable impurities, cold rolling the plastic worked alloy, and annealing the alloy after cold rolling. The shock absorber according to any one of claims 1 to 6, wherein the shock absorber is made of a wire material made of an Fe-Al damping alloy having a spring property so as to be 250 µm or less. Each of the collar member, the buffer member, the coupling member, and the connection target member,
The shock absorber according to any one of claims 1 to 7, wherein the shock absorbers are made of materials close to each other in ionization tendency in order to prevent the occurrence of electrolytic corrosion. A metal cover made of one or a plurality of aluminum alloy plates each having a corrugated shape extending in a direction intersecting with each other and having a three-dimensional shape,
Crushing the corrugated shape of the crushing target site to form a substantially flat plate shape,
Either one of the directions intersecting with each other is defined as a direction intersecting with a main ridge line corresponding part constituting the three-dimensional shape,
Using the shock absorber according to any one of claims 1 to 8,
The metal cover which comprised the said vibration side object member with the internal combustion engine and / or its exhaust path, and hold | maintained the said crushing object site | part with a said 1st holding | maintenance part. The directions intersecting each other are defined as a first direction and a second direction orthogonal to each other,
The corrugated shape,
The ridges and valleys each extending along the first direction are alternately repeated in the second direction,
The raised portions are alternately arranged along the first direction, with the first rising portions and the second rising portions rising from the valley portions,
In the valley, the flat portions and the recesses are alternately arranged along the first direction,
The first upright portion includes a pair of side walls that rise in a substantially inverted trapezoidal shape from the trough portion, and a relatively flat top portion formed by connecting tips of the side walls to each other. The upright portion is inwardly curved, and the distal end portion is wider than the proximal end portion of the first upright portion,
The second upright portion is composed of a pair of side walls that respectively rise from the flat portion, and a concave recess that interconnects the tips of the side walls,
The metal cover according to claim 9, wherein the first upright portion and the concave portion, and the second upright portion and the flat portion are formed to be intermittently connected along the second direction.

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