JP3669932B2 - Cushioning material for heat shield support device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The buffer material of the support device for a heat shield according to the present invention is incorporated in a support device for a heat shield that supports a heat shield installed in a state of covering a portion that becomes high during operation, such as an exhaust manifold, a turbocharger, This is to prevent unpleasant noise from being generated due to vibration transmitted during driving.
[0002]
[Prior art]
In order to guide the exhaust of an automobile engine, the temperature of the exhaust manifold having the upstream end connected to the side surface of the cylinder head of the engine rises considerably due to the heat of the exhaust flowing inside. In order to protect other equipment installed in the engine room from the radiant heat radiated from the exhaust manifold whose temperature has increased in this way, the exhaust manifold is covered with a heat shield plate called a heat insulator, and the exhaust manifold is Radiant heat is prevented from being transmitted to the other devices. The same applies to the turbocharger for supercharging the engine.
[0003]
FIG. 5 shows an example of such a heat shield plate 1. The heat shield plate 1 can cover the exhaust manifold with a slight gap interposed therebetween by pressing a single plate of a steel plate or a composite plate in which a sound absorbing material is sandwiched with a steel plate subjected to aluminum plating. It is formed in various shapes and sizes. Such a heat shield plate 1 is supported and fixed to a mounting portion such as a mounting seat provided in the exhaust manifold by a coupling member such as a bolt or a stud inserted into circular mounting holes 2 and 2 provided at a plurality of locations. Yes.
[0004]
Since this exhaust manifold radiates sound coming out of the engine when the engine is operated, the heat shield 1 is vibrated so that the heat shield 1 does not vibrate on the basis of the radiated sound and no harsh noise is generated. And a buffer member is provided between the coupling member and the coupling member. FIG. 6 shows an example of a conventional structure of a heat shield plate support device for supporting and fixing the heat shield plate 1 to the mounting portion. In this conventional structure, a cylindrical sleeve 3 is inserted inside a mounting hole 2 formed in a plurality of locations on the heat shield plate 1 and each having a circular shape. Further, in the peripheral portion of the mounting hole 2, a pair of annular cushioning materials 4 and 4 constituting the cushioning unit, which is a subject of the present invention, is sandwiched from the heat shield plate 1 from both the front and back sides. It is arranged with. Each of the cushioning materials 4 and 4 is made of a material formed by braiding a filament made of heat-resistant material having elasticity such as stainless steel by knit knitting into an intermediate material, and this intermediate material is further moved in the axial direction. By forming by pressure, the whole is formed in an annular shape with a rectangular cross section. In addition, washers 5 and 5 each having an L-shaped cross section and having an annular shape as a whole are superimposed on the outer end surfaces (side surfaces opposite to the heat shield plate 1) of the cushioning materials 4 and 4. In the case of the conventional structure shown in FIG. 6, the inner diameters of the buffer materials 4 and 4 are larger than the inner diameter of the mounting hole 2, and the inner diameters of the washers 5 and 5 are larger than the inner diameter of the mounting hole 2. Is also small.
[0005]
In order to support and fix the heat shield plate 1 to the mounting portion by using a conventional heat shield plate support device formed by combining the above-described members, a coupling member (not shown) such as a bolt or a stud is attached to the sleeve. 3 and this coupling member and a screw hole formed in the mounting portion (when the coupling member is a bolt) or a nut (when the coupling member is a stud with its base end fixed to the mounting portion) And then tighten further. In this state, the sleeve 3 is firmly clamped between the outer end surface of the mounting portion and the head or nut of the bolt, and is fixed to the mounting portion. At the same time, the buffer materials 4 and 4 are elastically compressed between the front and back surfaces of the heat shield plate 1 and the washers 5 and 5, so that the heat shield plate 1 is buffered against the mounting portion. Supported by
[0006]
In the case of the conventional structure as described above, the inner peripheral edge of the mounting hole 2 and the outer peripheral surface of the intermediate portion of the sleeve 3 are directly opposed without the cushioning material 4 interposed therebetween. For this reason, the heat shield 1 can be displaced in the diameter direction of the sleeve 3 due to the vibration generated during the operation of the engine, and the outer peripheral surface of the intermediate portion of the sleeve 3 can be brought into contact with the inner peripheral edge of the mounting hole 2. There is sex. When vibration is applied while the outer peripheral surface of the intermediate portion of the sleeve 3 and the inner peripheral edge of the mounting hole 2 formed in the heat shield plate 1 are in contact with each other, each of which is a metal rigid body, chatter noise is generated at the contact portion. This is undesirable because it causes discomfort to the passengers and those around.
[0007]
[Description of the invention]
The present inventors previously invented a structure as shown in FIG. 7 as a heat shield supporting device that can eliminate such inconvenience (Japanese Patent Application No. 11-295298). In the structure according to the present invention, a cylindrical sleeve 3 made of metal such as steel or stainless steel is provided inside a circular mounting hole 2 formed in the heat shield plate 1, and a buffer unit 6 made of heat resistant material having elasticity is provided. Through. The heat shield plate 1 is buffered and supported by a mounting portion provided at a high temperature portion during operation, such as an exhaust manifold, by a coupling member (not shown) such as a bolt or a stud inserted through the sleeve 3. The buffer unit 6 is sandwiched from both sides in the axial direction (vertical direction in FIG. 7) by washers 5 and 5 each having an L-shaped cross section and having an annular shape as a whole. The inner diameter of the cylindrical portion 7 formed on the inner peripheral edge portions of both washers 5 and 5 is set to a size that allows the sleeve 3 to be loosely fitted, and the outer diameter is set smaller than the inner diameter of the mounting hole 2. ing.
[0008]
The buffer unit 6 is formed by combining a pair of buffer materials 4a and 4a, each having an annular shape and the same shape, arranged symmetrically with respect to the axial direction (vertical direction in FIG. 7). Each of the cushioning materials 4a and 4a is formed with an annular convex portion 9 on the surface facing each other and an annular concave portion 10 on the opposite surface of the inner peripheral edge of the main portion 8 having a rectangular cross section. It consists of Of these, the convex portion 9 is sized to enter the mounting hole 2, and the concave portion 10 is sized to allow the cylindrical portion 7 to be inserted.
[0009]
Each of the buffer materials 4a and 4a of the heat shield supporting device as described above is formed by braiding stainless steel filaments having an outer diameter of 0.08 to 0.20 mm, preferably 0.10 to 0.15 mm. 8 is wound to form a cylindrical intermediate material 12 as shown in FIG. 9, and this intermediate material 12 is formed by pressure molding. Each of the buffer materials 4a and 4a obtained after the pressure molding has an apparent bulk density of 0.12 to 0.20, preferably 0.14 to 0.18. If the outer diameter of the filament is less than 0.08 mm, the rigidity of the filament is too low, making it difficult to obtain the elasticity required for each of the cushioning materials 4a and 4a. It becomes difficult to maintain a sufficient vibration control effect. On the other hand, when the outer diameter of the filament exceeds 0.20 mm, the rigidity of the filament becomes too high, the rigidity of the cushioning materials 4a and 4a becomes too high, and the damping effect becomes low. If the outer diameter is restricted to 0.08 to 0.20 mm, preferably 0.10 to 0.15 mm, a sufficient damping effect can be obtained from the initial stage until a long time has elapsed.
[0010]
Further, when the apparent bulk density is less than 0.12, the porosity is too high, and the cushioning materials 4a and 4a can be provided with necessary elasticity by deforming with a very light force. It becomes difficult to maintain a sufficient damping effect over a long period of time. On the other hand, when the apparent bulk density exceeds 0.20, the porosity is too low, the force required for deformation is increased, the rigidity of the cushioning materials 4a, 4a is too high, and The vibration effect is reduced. If the apparent bulk density is regulated to 0.12 to 0.20, preferably 0.14 to 0.18, a sufficient vibration damping effect can be obtained from the initial stage until a long time has elapsed. Further, the thickness T _4a of the cushioning materials 4a and 4a excluding the convex portions 9 and 9 is 2 to 5 mm, preferably 3 to 4 mm in the assembled state as shown in FIG. If the thickness T _4a is too small, the rigidity becomes too high, and if it is too large, the rigidity becomes too low. In any case, it is difficult to obtain a sufficient damping effect over a long period of time. .
[0011]
The ratio of the thickness T _4a in the assembled state to the thickness in the free state is about 0.85 to 0.95. When this ratio is too small (when the amount of compression of each of the cushioning materials 4a and 4a associated with the assembly is too large), the rigidity of each of the cushioning materials 4a and 4a becomes too high, and the damping effect becomes low. . On the other hand, when the ratio is too large (when the amount of compression of the cushioning materials 4a and 4a associated with the assembly is too small), not only the support rigidity of the heat shield plate 1 becomes too low, but also the long When the buffer materials 4a and 4a are damaged due to use over a period, the heat shield plate 1 may be rattled .
[0012]
Each buffer material 4a, 4a of the support device for a heat shield plate as described above has each convex portion 9 formed in an annular gap 13 between the inner peripheral edge of the mounting hole 2 and the outer peripheral surface of the intermediate portion of the sleeve 3. The end edges of the projections 9 and 9 of the cushioning materials 4a and 4a are abutted or closely opposed at the axial central portion of the annular gap 13, A buffer unit 6 is configured. In this way, a coupling member (not shown) such as a bolt or a stud is inserted into the sleeve 3 supported via the buffer unit 6 inside the mounting hole 2, and the coupling member and the exhaust manifold are inserted. Alternatively, a screw hole or a nut formed in a mounting portion provided in the turbocharger is screwed and further tightened. In this state, the sleeve 3 is firmly clamped between the outer end surface of the mounting portion and the head or nut of the bolt, and is fixed to the mounting portion. At the same time, the buffer materials 4a and 4a constituting the buffer unit 6 are elastically compressed between the front and back surfaces of the heat shield plate 1 and the washers 5 and 5, so that the heat shield plate 1 is The mounting portion is supported in a cushioning manner. Since the sleeve 3 is stretched between the outer end surface of the mounting portion and the head or nut of the bolt, the buffer materials 4a and 4a are excessively compressed along with the screwing and tightening operations. There is nothing to do.
[0013]
According to the support device for a heat shield plate of the previous invention configured as described above, the inside of the annular gap 13 between the inner peripheral edge of the mounting hole 2 formed in the heat shield plate 1 and the outer peripheral surface of the intermediate portion of the sleeve 3. In addition, there are convex portions 9 and 9 provided on the pair of cushioning materials 4a and 4a constituting the cushioning unit 6, respectively. Each of these convex portions 9 and 9 is also elastically deformable with many minute gaps inside, like the other portions of each of the buffer materials 4a and 4a. For this reason, each said convex part 9 and 9 prevents that the inner periphery of the said mounting hole 2 and the intermediate part outer peripheral surface of the said sleeve 3 contact | abut directly, and can aim at generation | occurrence | production prevention of chatter sound reliably.
[0014]
[Problems to be solved by the invention]
As described above, the apparent bulk density is 0.20 or less, preferably 0. 0, in order to sufficiently secure the buffering action by the cushioning materials 4a, 4a constituting the heat shield supporting device according to the above-described invention. It is necessary to suppress it to 18 or less. By the way, as described above, the cushioning material 4a of the heat shield supporting device is formed by winding the bag-shaped material 11 as shown in FIG. 8 to form the cylindrical intermediate material 12 as shown in FIG. This intermediate material 12 is formed by compression molding between an upper die 16 and a lower die 17 as shown in FIG. Accordingly, a terminal edge 14 when the material 11 is wound is present on the outer peripheral surface of the cushioning material 4a. The terminal edge 14 is not subjected to fraying prevention measures such as welding. The reason for this is to simplify the process and keep the manufacturing cost of the buffer material 4a low.
[0015]
In this way, if the terminal edge 14 is not subjected to fraying prevention measures and the bulk density of the buffer material 4a is kept low, the vibration applied to the buffer material 4a during use of the heat shield supporting device will be described. As shown in FIG. 11, the end edge 14 is easily frayed. If frayed, the durability of the cushioning material 4a is impaired. In order to prevent the fraying that leads to such a decrease in durability, it is conceivable to increase the bulk density of the cushioning material 4a or to treat the terminal edge 14 to prevent fraying such as welding. However, since increasing the bulk density leads to a decrease in the vibration damping effect due to improved rigidity, it is difficult to adopt. Further, the fraying prevention treatment is not preferable because it leads to an increase in manufacturing cost of the cushioning material 4a.
In view of such circumstances, the present invention was invented to realize a cushioning material for a support device for a heat shield that prevents the end edge 14 from fraying regardless of vibration applied during use, while suppressing an increase in manufacturing cost. It is.
[0016]
[Means for Solving the Problems]
The cushioning material of the heat shield support device of the present invention can be elastically deformed by press-molding an intermediate material formed by winding only a material made by braiding only filaments made of heat-resistant material having elasticity. The whole is formed in an annular shape with a density.
In particular, in the case of the cushioning material of the heat shield support device of the present invention, a circumferential ridge is formed at the axially intermediate portion of the outer circumferential surface , and the apparent bulk density value of this ridge portion is set to 0. 0. As 5 or more, it is higher than 0.12 to 0.20 which is the value of the apparent bulk density of other portions.
[0017]
[Action]
When the cushioning material of the heat shield support device of the present invention as described above is incorporated in the heat shield support device, it is possible to prevent generation of annoying noise due to vibration transmitted during operation. The operation is the same as that of the cushioning material of the conventional heat shield supporting device shown in FIG. 6 or the prior invention shown in FIG.
Particularly, in the case of the cushioning material of the hot plate supporting device shielding of the present invention is to form a circumferential ridge on the axially intermediate portion of the outer peripheral surface, the bulk of the other portions of the bulk density of the ridge portion Since the density is higher than the density, the material constituting the cushioning material of the support device for the heat shield plate is frayed from the outer peripheral surface portion of the cushioning material of the support device for the heat shield plate while suppressing an increase in manufacturing cost. Can be prevented.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
1 to 4 show an example of an embodiment of the present invention. The feature of the present invention is that the shape and density of the buffer material 4b are devised in order to prevent the material constituting the buffer material 4b of the support device for the heat shield plate from fraying from the outer peripheral surface portion of the buffer material 4b. It is in the point. The cushioning material 4b is formed in a cylindrical shape as shown in FIG. 9 by winding a bag-shaped material 11 as shown in FIG. 8 in the same manner as the cushioning material 4a incorporated in the heat shield supporting device according to the previous invention. The intermediate material 12 is made, and this intermediate material 12 is compression-molded. Therefore, the description regarding the same parts as those of the above-described invention will be omitted or simplified, and the following description will focus on the characteristic parts of the present invention.
[0019]
In the case of the cushioning material 4b of the heat shield support device of the present invention, the circumferential protrusion 15 is formed over the entire circumference in the axially intermediate portion of the outer peripheral surface. When the intermediate material 12 is compression-molded as shown in FIG. 10 to form the cushioning material 4b, the ridges 15 are configured so that the amount of compression in the axial direction of the portion near the outer diameter of the intermediate material 12 is the It is formed by making it more than the amount of compression. For this purpose, projecting portions 18 and 19 as shown in FIG. 10 are provided around the outer periphery of the lower surface of the upper die 16 and the outer surface of the lower die 17 for compression molding the intermediate material 12 as shown in FIG. It is formed over. Then, the portion near the outer diameter of the intermediate material 12 is compressed more than the other portions between the projecting portions 18 and 19 to form the protrusion 15. In this way, in order to form the protrusion 15, it is only necessary to form the protrusions 18 and 19 on the upper mold 16 and the lower mold 17. It is scarce. The rigidity of the ridge 15 determined by the density of the ridge 15 can be arbitrarily adjusted by changing the height of each of the protrusions 18 and 19 and changing the thickness t of the ridge 15.
[0020]
In the case of the buffer material 4b of the heat shield support device of the present invention, the density of the ridges 15 is made higher than the density of the parts other than the ridges 15 in this way. As described above, the apparent bulk density of the portion other than the protrusions 15 is restricted to 0.12 to 0.20, preferably 0.14 to 0.18, from the viewpoint of securing the vibration damping effect. On the other hand, the apparent bulk density of the ridge portion 15 is sufficiently higher than this in view of fraying prevention and is a value close to 1 (0.5 or more) . For example, when the outer diameter D of the cushioning material 4b is 18 to 30 mm, the inner diameter R is 8 to 15 mm, and the thickness T of the portion excluding the convex portion 9 is 3 to 8 mm, the thickness t of the protrusion 15 is It is appropriate that the width w in the radial direction is about 0.5 to 1.0 mm. When the buffer material 4b having such dimensions is manufactured, when the intermediate material 12 is pressure-formed between the upper mold 16 and the lower mold 17, a portion closer to the outer diameter of the intermediate material 12 is formed. A part of the filament escapes (flows) radially inward from between the protrusions 18 and 19. The dimensions D, R, T, t, and w are determined by design in consideration of such relief.
[0021]
As shown in FIG. 4, the buffer material 4b of the support device for a heat shield plate of the present invention as described above includes a buffer unit 6a together with a sleeve 3 and a pair of washers 5, 5, as shown in FIG. Constitute. Then, using this buffer unit 6a, the heat shield plate 1 is supported by a bolt 21 on a fixed portion 20 such as an exhaust manifold. In a state where the bolt 21 is tightened, the sleeve 3 is stretched between the fixed portion 20 and the washer 22, and a pair of cushioning materials 4b and 4b are disposed between the washers 5 and 5 and the heat shield plate 1. Elastically compressed. For this reason, the heat shield 1 is supported by the fixed portion 20 in a cushioning manner.
[0022]
During the operation of the engine, vibrations in the directions indicated by arrows α and β in FIG. 4 are applied to the cushioning materials 4b and 4b. For this reason, when no countermeasures are taken, the material constituting the cushioning material is likely to fray from the outer peripheral surface portion of the cushioning material as shown in FIG. On the other hand, in the case of the cushioning material 4b of the heat shield support device of the present invention, the circumferential protrusion 15 is formed at the axially intermediate portion of the outer peripheral surface , and the apparent bulk of the protrusion 15 portion. Since the density value is 0.5 or more and higher than 0.12 to 0.20 which is the apparent bulk density value of other portions, the above-mentioned cushioning material 4b is configured while suppressing an increase in manufacturing cost. It can prevent that the raw material to be frayed from the outer peripheral surface part of this buffer material 4b. For this reason, durability improvement of this buffer material 4b can be aimed at. The apparent bulk density (0.12 to 0.20, preferably 0.14 to 0.18) of the portion between the heat shield plate 1 and the pair of washers 5 and 5 is the same as in the case of the previous invention. Similarly, since it is set to an optimum value in terms of the vibration damping effect, the vibration suppressing action is not impaired. In particular, in the case of the present invention, the apparent bulk density of the portion other than the ridges 15 can be set to an optimum value (can be reduced) from the viewpoint of simply improving the vibration damping effect without considering fraying prevention. Compared with the case of the prior invention, it is also possible to further improve the vibration suppressing action.
[0023]
【The invention's effect】
According to the present invention, it is possible to improve the durability of the cushioning material of the support device for the heat shield plate while suppressing an increase in manufacturing cost, and to produce a stable performance without generating vibration noise. A plate support device can be realized at low cost.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of the present invention.
FIG. 2 is a cross-sectional view taken along the line AA in FIG.
FIG. 3 is an enlarged view of a portion B in FIG.
FIG. 4 is a cross-sectional view showing the heat shield plate support device incorporating the cushioning material of the heat shield plate support device of the present invention in the middle of assembly.
FIG. 5 is a perspective view showing an example of a heat shield plate.
FIG. 6 is an enlarged CC cross-sectional view of FIG. 5 showing an example of a conventional structure.
FIG. 7 is a view similar to FIG. 6, showing an example of the embodiment of the prior invention.
FIG. 8 is a schematic perspective view of a material formed by braiding filaments to constitute a buffer material of a support device for a heat shield plate.
FIG. 9 is a schematic perspective view of an intermediate material formed by winding this material.
FIG. 10 is a schematic cross-sectional view showing a process of pressing the intermediate material in the axial direction to form a cushioning material for a heat shield support device.
FIG. 11 is a schematic perspective view showing a state in which the cushioning material of the heat shield supporting device obtained by this pressure molding is frayed from the outer peripheral side.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Heat-shield plate 2 Mounting hole 3 Sleeve 4, 4a, 4b Buffer material 5 Washer 6, 6a Buffer unit 7 Cylindrical part 8 Main part 9 Convex part 10 Concave part 11 Material 12 Intermediate material 13 Annular gap 14 Termination edge 15 Protrusion 16 Top Mold 17 Lower mold 18 Protruding part 19 Protruding part 20 Fixed part 21 Bolt 22 Washer

Claims (1)

Support for heat shield plate that is formed in an annular shape with an elastically deformable density by press-molding an intermediate material that is formed by winding only an elastic heat-resistant filament braided material in an annular shape It is a cushioning material for the device, and a ridge in the circumferential direction is formed in the axially intermediate portion of the outer peripheral surface , and the apparent bulk density of this ridge portion is set to 0.5 or more, and the apparent bulk density of other portions The cushioning material of the support device for heat shield plates made higher than the value of 0.12 to 0.20 .

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