Vibration damping composite body and vibration damping composite body equipped with a metal spring using the same

Abstract

Vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) comprising a first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) and a second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232) which overlap one another, characterized in that the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) is made of a material with a higher damping than that of the second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232), the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) has a recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) which opens onto a surface of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), and the recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) forms a gap (22, 48, 58, 68, 79, 96, 142, 172, 236), and a stress concentration part (28) configured to be subjected to increased stress during a load action is placed on a wall of the gap (22, 48, 58, 68, 79, 96, 142, 172, 236) of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), wherein the first elastic body (12, 32, 52, 62, 82, 132, 162, 186, 224) and the second elastic body (14, 34, 54, 84, 134, 164, 188, 232) overlap in a direction of load action, and wherein the first elastic body (12, 32, 82, 132, 162, 186, 224) has a protruding part (16, 38, 86, 136, 166, 228) which is provided on an overlapping surface with the second elastic body (14, 34, 84, 134, 164, 188, 232) and protrudes towards the second elastic body (14, 34, 84, 134, 164, 188, 232), and the recessed part (18, 40, 88, 138, 168, 226) is formed on an outer periphery of the protruding part (16, 38, 86, 136, 166, 228).

Description

TECHNICAL FIELD

[0001] For example, the present invention relates to a vibration-damping composite body used for holding a main component of a vibration transmission system in a vibration-damping connection state or for limiting the amount of relative displacement between main components of a vibration transmission system. The present invention further relates to a vibration-damping composite body equipped with a metal spring using the same. STATE OF THE ART

[0002] Conventionally, a composite vibration damping body having a structure in which a plurality of elastic bodies overlap each other has been proposed as a vibration damping body adapted for use, for example, as a door stopper that positions a vehicle door relative to a body frame, a stopper mechanism of a vibration damping device such as an engine mount, and the like. Specifically, such as a stopper shown in Japanese Patent Application Laid-Open No. 2016-125528 (Patent Document 1), the composite vibration damping body has a structure in which an outer body and an inner body formed of a rubber-like elastic body overlap each other. By differentiating the hardness of the outer body and the inner body from each other, it is possible to obtain a large degree of freedom in adjusting the spring characteristics.

[0003] Meanwhile, the damping effect shown by deformation of the elastic body during a load action is largely maintained by a large stress generated by the elastic body.

[0004] However, in the case of the stopper in Patent Document 1, the stress during load application is distributed by the complete deformation of the outer body and the inner body, resulting in a comparatively weak damping effect. Thus, the vibration damping capability may be insufficient. PRIOR ART DOCUMENT

[0005] Patent Document 1: JP 2016 - 125 528 A

[0006] EP 1 048 552 A2 describes a non-return buffer for a car body mount. The non-return buffer comprises an outer buffer made of an elastomer material with a first hardness. The non-return buffer further comprises an inner buffer made of an elastomer material with a second hardness, wherein the first hardness of the outer buffer is higher than the second hardness of the inner buffer. A clamping disc holds the inner buffer in contact with the outer buffer. The outer buffer includes an annular lip for retaining the clamping disc. The separate inner buffer enables the design and / or tuning of a vertical damping rate defined by the inner buffer, independent of the lateral damping rate.

[0007] DE 41 14 879 A1 describes a spring-rate-switchable engine mount consisting of a support bearing and a support, which are arranged relatively movably transversely to an axis and supported by a first and a second rubber spring element. The second spring element can be locked by an auxiliary device if necessary. The first and second spring elements are connected in series and separated from each other by a dimensionally stable support plate.

[0008] US 7,281,705 B2 describes a suspension system for a vehicle having a vehicle body and a plurality of wheels movable relative to the vehicle body. A hydraulic damper comprising a piston rod and a cylinder is arranged between the vehicle body and the wheels. A striker plate is mounted on the cylinder and is displaceable with the cylinder relative to a support on the vehicle body. A stop assembly is mounted on the support around the piston rod and extends outwardly toward the striker plate. The jounce assembly comprises a jounce bumper and a cap. The cap is mounted on the jounce bumper, the cap having a flange extending to a distal edge to define a cavity. The distal edge of the flange bends into the cavity when the cap engages the striker plate during a predetermined displacement of the striker plate relative to the support.

[0009] CN 2 02 707 891 U describes a damping device for a steering wheel for an automobile. The damping device consists of a damping block, a damping rubber block, and a mounting plate, wherein the center of the front end and the lower end of the damping block are provided with inward-facing grooves. The groove of the lower end of the center of the damping block is provided with the damping rubber block, the lower end of the damping rubber block is connected and provided with a connecting plate, and the front end of the connecting plate, which faces the damping block, extends horizontally and is horizontally connected, provided, and fixed to the mounting plate. The damping device offers the advantages of a simple structure, low cost, convenient and attractive installation, the ability to effectively reduce steering wheel vibration, and improved steering wheel stability. SUMMARY OF THE INVENTION TASK TO BE SOLVED BY THE INVENTION

[0010] The present invention has been developed in view of the above-described subject matter as background, and it is an object of the present invention to provide a vibration damping composite body having a novel construction capable of realizing even better vibration damping performance and to provide a vibration damping composite body equipped with a metal spring using the same. MEANS TO SOLVE THE TASK

[0011] The above and / or optional objects of this invention can be achieved according to at least one of the embodiments of the invention according to the vibration-damping composite body according to claim 1, the vibration-damping composite body equipped with a metal spring according to claim 7, or the vibration-damping composite body equipped with a metal spring according to claim 9. The following preferred embodiments and / or elements employed in each preferred embodiment of the invention can be adopted in any possible optional combination.

[0012] In particular, a first embodiment of the present invention provides a vibration damping composite body comprising a first elastic body and a second elastic body that overlap each other, characterized in that: the first elastic body is formed of a material having higher damping than that of the second elastic body; the first elastic body has a depressed part opening onto a surface of the first elastic body, and the depressed part forms a gap; and a stress concentrating part configured to be subjected to an increased stress during a load application is set on a wall of the gap of the first elastic body.

[0013] According to the composite vibration damping body constructed according to the first embodiment, the first elastic body is formed of a high-damping material, and the stress due to the load action is concentrated in the stress concentration part of the first elastic body located at the recessed part. This makes it possible to obtain a large damping effect, thereby realizing excellent vibration damping performance.

[0014] Furthermore, the stress concentration part is arranged on the wall of the gap provided by the recessed part. Accordingly, the stress of the first elastic body is largely generated in the stress concentration part without being restricted by the second elastic body inserted into the recessed part, thereby effectively achieving the damping effect in the stress concentration part.

[0015] A second preferred embodiment of the present invention provides the vibration damping composite body according to the first embodiment, wherein the recessed part of the first elastic body has a groove shape.

[0016] According to the second preferred embodiment, since the recessed portion has a groove shape, the gap formed by the recessed portion and the stress concentration portion arranged on the wall of the gap can both be largely achieved in the longitudinal direction of the recessed portion. This makes it possible to more advantageously achieve the damping effect due to the stress of the stress concentration portion in the first elastic body, thus realizing excellent vibration damping performance.

[0017] A third preferred embodiment of the present invention provides the vibration damping composite body according to the first or second preferred embodiment, wherein the recessed part of the first elastic body is opened to a lateral side with respect to a direction of load action.

[0018] According to the third preferred embodiment, the first elastic body deforms during the application of a load to narrow the opening of the recessed portion, thereby making it possible to concentrate the stress on the inner surface of the recessed portion. Thus, the damping effect is effectively achieved.

[0019] The embodiment of the present invention provides the vibration damping composite body according to the first embodiment, wherein the first elastic body and the second elastic body overlap in a direction of load action.

[0020] According to this embodiment, for example, by forming the second elastic body from a material having excellent shock absorption effect or durability over the first elastic body, the vibration damping composite body is capable of simultaneously achieving shock absorption effect, durability or the like due to the second elastic body in addition to the excellent vibration damping effect due to the damping effect of the first elastic body.

[0021] The embodiment of the present invention provides the vibration damping composite body according to the first embodiment, wherein the first elastic body has a protruding part provided on an overlapping surface with the second elastic body and protruding toward the second elastic body, and the depressed part is formed on an outer periphery of the protruding part.

[0022] According to this embodiment, the protruding part is compressed by load action, and the protruding part elastically deforms to expand radially outward according to a Poisson's ratio, thereby achieving a large stress in the stress concentration part formed on the outer periphery of the protruding part.

[0023] A sixth preferred embodiment of the present invention provides the vibration damping composite body according to the first to third preferred embodiments inclusive, wherein a projecting distal end surface of the projecting part is in contact with the second elastic body, and the first elastic body and the second elastic body are in contact with each other at a position away from the projecting part to a radially outer side in a projecting direction of the projecting part.

[0024] According to the sixth preferred embodiment, since the first elastic body and the second elastic body are in contact with each other not only at the protruding distal end surface of the protruding part but also at the position away from the protruding part to the radial outside, excellent load-bearing capacity or the like can be realized.

[0025] A seventh preferred embodiment of the present invention provides the vibration damping composite body according to any one of the first to sixth preferred embodiments inclusive, wherein the depressed part is opened to an overlapping surface of the first elastic body with the second elastic body, the second elastic body has a convex part fitted into the depressed part, the convex part partially contacts an inner surface of the depressed part, and the gap is formed between the convex part and the inner surface of the depressed part.

[0026] Further, according to the seventh preferred embodiment, since the convex part is inserted into the depressed part and partially in contact with it, it is possible to connect the first elastic body and the second elastic body by engaging the convex part with the depressed part. Furthermore, when the first elastic body elastically deforms due to the action of a load, the convex part inserted into the depressed part is gripped by the first elastic body to elastically deform, thereby making it possible to further achieve a damping effect. Note that the gap is formed between the convex part and the inner surface of the depressed part. Thus, deformation of the stress concentration part of the first elastic body and deformation of the convex part of the second elastic body occur without interfering with each other.

[0027] An eighth preferred embodiment of the present invention provides the vibration damping composite body according to any one of the first to seventh preferred embodiments inclusive, wherein the second elastic body is formed of a material having a smaller compression set than that of the first elastic body.

[0028] According to the eighth preferred embodiment, the vibration-damping composite body is equipped with the first elastic body formed of a high-damping material and the second elastic body less susceptible to permanent strain, thereby achieving excellent vibration damping performance, shock absorption performance, positioning capability, or the like. Here, compression set refers to the amount of stress due to a history of static compressive load under the same condition.

[0029] Another embodiment of the present invention provides a metal spring-equipped vibration-damping composite body comprising: the vibration-damping composite body according to any one of the first to eighth preferred embodiments; and a metal spring provided in series with the vibration-damping composite body in a direction of load action.

[0030] According to the metal spring-equipped vibration-damping composite body constructed according to this further embodiment, permanent strain of the vibration-damping composite body is prevented when a static load is applied for a long period of time, for example, by elastic deformation of the metal spring. Furthermore, compared to an elastic body such as a rubber or an elastomer, the metal spring is less likely to undergo time-dependent permanent strain, thereby preventing a change in the size of the metal spring-equipped vibration-damping composite body due to plastic deformation of the metal spring or the like.

[0031] A tenth preferred embodiment of the present invention provides the vibration-damping composite body according to the further embodiment, wherein the metal spring has an attachment part for a component to be damped.

[0032] According to the tenth preferred embodiment, the vibration-damping composite body can be attached to the component to be damped through the metal spring. This makes it possible to reduce the number of parts compared to the case where a component for attachment is provided separately from the metal spring, and to achieve a simple structure.

[0033] An eleventh preferred embodiment of the present invention provides the vibration damping composite body according to the further or tenth preferred embodiment, wherein the metal spring comprises a disc spring folded at a bending part.

[0034] According to the eleventh preferred embodiment, the orientation of the vibration-damping composite body can be easily adjusted by adjusting the angle formed by the opposite side portions of the bent part of the metal spring. Specifically, in the case of using the vibration-damping composite body equipped with a metal spring as a stopper for a vehicle door that can be opened and closed with respect to a body frame via a hinge, the position of the hinge, which is the center of displacement of the vehicle door, and the position of the center of deformation of the metal spring are different from each other.Thus, the contact configuration of the vehicle door with respect to the vibration damping composite body changes as the displacement amount of the vehicle door increases, making it possible to concentrate the stress on the stress concentration part of the first elastic body or the like. EFFECT OF THE INVENTION

[0035] According to the present invention, the first elastic body is formed of a material having higher damping than that of the second elastic body, and stress due to load action is concentrated in the stress concentration part located at the depressed part. Accordingly, an excellent vibration damping effect is exhibited in the stress concentration part of the first elastic body, thereby advantageously achieving a vibration damping effect due to energy attenuation. Furthermore, since the stress concentration part is fitted to the wall of the gap formed by the depressed part, the deformation in the first elastic body in the stress concentration part largely occurs without being hindered by the second elastic body, thereby more effectively achieving the damping effect. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view taken along line 1-1 of Fig. 2, which illustrates a vibration-damping composite body in the form of a doorstop as a first practical embodiment of the present invention. Fig. 2 is a cross-sectional view taken along line 2-2 of Fig. 1. Fig. 3 is a view showing a simulation result of a stress distribution when the Fig. 1 is compressed in the axial direction. Fig. 4 is a cross-sectional view taken along line 4-4 of Fig. 5, which illustrates a doorstop as a second practical embodiment of the present invention. Fig. 5 is a cross-sectional view taken along line 5-5 of Fig. 4. Fig. 6 is a view showing a simulation result of a stress distribution when the Fig. 4 shown doorstop is compressed in the axial direction. Fig. 7 is a cross-sectional view illustrating a doorstop as a third practical embodiment of the present invention. Fig. 8 is a cross-sectional view illustrating a doorstop as a fourth practical embodiment of the present invention. Fig. 9 is a cross-sectional view illustrating a doorstop as a fifth practical embodiment of the present invention. Fig. 10 is a front view illustrating a vibration damping composite body in the form of a stopper rubber as a sixth practical embodiment of the present invention. Fig. 11 is a plan view of the Fig. 10 stop rubbers shown. Fig. 12 is a cross-sectional view taken along line 12-12 of Fig. 11. Fig. 13 is a partial cross-sectional view taken along line 13-13 of Fig. 14, which shows an example in which the Fig. 10 shown stop rubber is used in a vibration damping device. Fig. 14 is a cross-sectional view taken along line 14-14 of Fig. 13. Fig. 15 is a front view of a tubular vibration damping device equipped with a stopper rubber as a seventh practical embodiment of the present invention. Fig. 16 is a front view of a tubular vibration damping device equipped with a stopper rubber as an eighth practical embodiment of the present invention. Fig. 17 is a front view illustrating a metal spring-equipped vibration-damping composite body in the shape of a doorstop as a ninth practical embodiment of the present invention. Fig. 18 is a plan view of the Fig. 17 shown doorstop. Fig. 19 is a cross-sectional view taken along line 19-19 of Fig. 17. Fig. 20 is a cross-sectional view taken along line 20-20 of Fig. 19. Fig. 21 is a view showing a simulation result of a stress distribution in a first elastic body when the Fig. 17 shown doorstop is compressed. Fig. 22 is a view showing a simulation result of a stress distribution in a metal spring when the Fig. 17 shown doorstop is compressed. Fig. 23 is a front view of a vibration damping device to which a vibration damping composite body equipped with a metal spring in the form of a stopper member is attached as a tenth practical embodiment of the present invention. EMBODIMENTS FOR CARRYING OUT THE INVENTION

[0036] In the following, practical embodiments of the present invention will be described with reference to the drawings.

[0037] Fig. 1 and Fig. 2 illustrate a doorstop 10 for a vehicle as a first practical embodiment of a vibration-damping composite body constructed according to the present invention. The doorstop 10 has a construction in which a first elastic body 12 and a second elastic body 14 are overlapped in series in the axial direction. In the description of the present practical embodiment, the vertical direction generally refers to the vertical direction in Fig. 1, which is the axial direction of the doorstop 10.

[0038] Described more specifically, the first elastic body 12 has a generally cylindrical shape as a whole and includes a small-diameter cylindrical protruding portion 16 integrally formed at the diametrically central portion and protruding upward. Further, the first elastic body 12 has a depressed portion 18 opening onto the outer peripheral surface of the proximal end of the protruding portion 16. The depressed portion 18 is formed such that the outer peripheral surface of the protruding portion 16 and the upper surface of the first elastic body 12 on the radially outer side of the protruding portion 16 serve as its wall surface. In the present practical embodiment, the depressed portion 18 has a groove shape opening upward and radially outward toward the lateral side and extending continuously around the entire circumference in the circumferential direction.

[0039] The first elastic body 12 is formed of rubber, a thermoplastic resin elastomer, or the like. Furthermore, the first elastic body 12 is formed of a material with higher damping, which is superior to the second elastic body 14 in energy attenuation performance. With respect to the first elastic body 12 in a preferred method, the loss factor (tan δ) is at least 0.3 in the case where vibration with a frequency of 25 Hz and an amplitude of ±0.5 mm is applied under room temperature conditions, and the first elastic body 12 exhibits excellent energy attenuation performance based on viscosity, which converts kinetic energy into heat energy.The dynamic properties of the first elastic body 12, including the loss tangent, can be specified, for example, based on “Elastomers or thermoplastic elastomers - Determination of dynamic properties” of JIS K6394.

[0040] Furthermore, while the constituent material of the first elastic body 12 is not particularly limited, for example, styrene-type rubber or butyl-type rubber are used. For example, styrene-butadiene rubber (SBR), isobutene-isoprene rubber (IIR), ethylene-propylene rubber (EPDM), or the like is preferably used. Besides that, the constituent material of the first elastic body 12 may be a thermoplastic elastomer. For example, SBR or the like, whose polymerization method is different from that of synthetic rubber, can be used appropriately.

[0041] The second elastic body 14 has a generally cylindrical shape overall and includes a generally circular depressed portion 20 opening downwardly from the diametrically central portion and projecting upwardly. The depressed portion 20 has a larger diameter than the projecting portion 16 of the first elastic body 12, and the depth dimension of the depressed portion 20 is approximately equal to or slightly smaller than the projecting height dimension of the projecting portion 16.

[0042] The second elastic body 14 is formed of rubber, a thermoplastic resin elastomer, or the like, and is preferably formed of a material having a lower compression set than that of the first elastic body 12. Furthermore, it is desirable that the second elastic body 14 have a compression set of at most 25% when continuously compressed in the vertical direction under a temperature condition of 85°C for 70 hours. The measurement method of the compression set of the second elastic body 14 is in accordance with "Rubber-based or thermoplastic elastomers - Determination of compression set at ambient, elevated, or low temperatures" defined in ISO 815 and JIS K6262 based thereon.

[0043] Furthermore, while the constituent material of the second elastic body 14 is not particularly limited, for example, natural rubber (NR) or butyl rubber (BR or the like) is preferably used. Besides that, acrylonitrile butadiene rubber (NBR), ethylene propylene rubber (EPM, EPDM), or the like can be used as the constituent material of the second elastic body 14, as appropriate.

[0044] The first elastic body 12 and the second elastic body 14 are arranged in series in the axial direction, which is the direction of load action described later, and are bonded to each other, for example, by an adhesive applied to the overlapping surfaces. In addition, the diameter of the first elastic body 12 and the diameter of the second elastic body 14 are approximately the same, and in the present practical embodiment, the first elastic body 12 is thicker in the axial direction than the second elastic body 14.

[0045] The doorstop 10 according to the present practical embodiment is configured such that, during the application of a load in the axial direction, which is assumed during use in a state described later, the amounts of deformation of the first elastic body 12 and the second elastic body 14 arranged in series in the axial direction are approximately equal to each other. Besides this, in the doorstop 10 of the present practical embodiment, as shown in Fig. 1, the first elastic body 12 is thicker than the second elastic body 14, and in particular, the difference in thickness between the formation portion of the protruding part 16 in the first elastic body 12 and the bottom portion of the depressed part 20 in the second elastic body 14 is set larger. As a result, the first elastic body 12 is formed of a hard material having a larger spring constant than that of the second elastic body 14. The hardness of the first elastic body 12 and the hardness of the second elastic body 14 can be specified, for example, based on "Elastomers or Thermoplastic Elastomers - Determination of Hardness" defined in JIS K6253-2.

[0046] Furthermore, the protruding part 16 of the first elastic body 12 protrudes on the overlapping surface with the second elastic body 14, and the depressed part 20 of the second elastic body 14 opens onto the overlapping surface with the first elastic body 12. The protruding part 16 of the first elastic body 12 is inserted into the depressed part 20 of the second elastic body 14. In the present practical embodiment, the protruding distal end surface of the protruding part 16 is in contact with the upper bottom surface of the depressed part 20, and the protruding distal end surface of the protruding part 16 is fixed to the upper bottom surface of the depressed part 20.

[0047] Furthermore, since the diameter of the protruding part 16 is smaller than that of the depressed part 20, the outer peripheral surface of the protruding part 16 and the inner peripheral surface of the depressed part 20 are spaced apart from each other in the radial direction. With this arrangement, the recessed part 18 is not filled with the second elastic body 14, so that a gap 22 formed by the recessed part 18 is formed between the first elastic body 12 and the second elastic body 14. At least a part of the wall of the gap 22 is formed from the wall of the recessed part 18, and the gap 22 includes the recessed part 18. In the present practical embodiment, the gap 22 has an annular shape continuous around the entire circumference with a generally constant rectangular cross section to be a closed space isolated from the outside.

[0048] In the present practical embodiment, the upper surface of the first elastic body 12 on the radially outer side of the protruding part 16 and the lower surface of the second elastic body 14 on the radially outer side of the opening of the depressed part 20 overlap in a contact state in the vertical direction and are fixed to each other at the position away from the protruding part 16 by the gap 22. As can be understood from the above, the protruding part 16 is inserted into the radially inner side of the depressed part 20 over the entire length in the axial direction, which is the protrusion direction, and the outer periphery of the protruding part 16 is surrounded by the second elastic body 14 over the entire length in the axial direction.

[0049] The doorstop 10 having such a construction is formed, for example, by the first elastic body 12 which is fixed to a body frame 24 of the vehicle as shown in Fig. 1, is mounted on a vehicle. Then, as shown in Fig. 3, when a door 26 serving as a vehicle door is closed, the second elastic body 14, which is the protruding distal end surface, is pressed against the door 26 and compressed in the axial direction between the body frame 24 and the door 26. In such a state, the doorstop 10 is configured to be disposed between the body frame 24 and the door 26. While the doorstop 10 is mounted on the vehicle, the first elastic body 12 forms the proximal end of the doorstop 10, which is attached to the body frame 24, and the second elastic body 14 forms the distal end of the doorstop 10, which is the door 26 side.

[0050] In addition, when a load in the axial direction acts on the doorstop 10 by closing the door 26 or the like, the doorstop 10 is compressed in the axial direction between the body frame 24 and the door 26, and the protruding part 16 is pressed in the axial direction toward the proximal end side.

[0051] Here, a stress concentration portion 28, where stress is concentrated, is located on the wall of the gap 22 formed by the recessed portion 18 provided at the proximal end of the protruding portion 16, and the stress of the first elastic body 12 increases locally during the application of load in the axial direction. That is, the wall of the recessed portion 18 is provided with a corner that includes the intersection line of the outer peripheral surface of the protruding portion 16 and the upper surface of the first elastic body 12 on the radially outer side of the protruding portion 16. When the doorstop 10 is compressed in the axial direction, stress is concentrated at this corner, and the stress increases. Thus, the corner serves as the stress concentration portion 28 in the present practical embodiment.Furthermore, since the recessed portion 18 forms the gap 22 without being filled with the second elastic body 14, elastic deformation of the first elastic body 12 in the recessed portion 18 is enabled by the gap 22, thereby adding stress in a concentrated manner. Consequently, the doorstop 10 is capable of achieving excellent vibration damping performance based on a large damping effect relative to the load effect in the axial direction due to the increased stress generated in the portion forming the wall of the gap 22 in the first elastic body 12 formed of a high damping material.

[0052] The stress concentration portion 28 provided to the recessed portion 18 of the present practical embodiment has a curved shape with a certain angle (approximately 90° in the present practical embodiment), and with respect to the action of loads in the axial direction, the first elastic body 12 deforms to reduce the opening angle formed by the inner surfaces of the recessed portion 18 at the stress concentration portion 28. Specifically, the first elastic body 12 deforms such that the outer peripheral surface of the protruding portion 16, which is one of the inner surfaces of the recessed portion 18 sandwiching the stress concentration portion 28, approaches the upper surface of the first elastic body 12 on the radially outer side of the protruding portion 16, which is the other of the inner surfaces.Accordingly, during the deformation of the first elastic body 12 due to the action of load in the axial direction, the gap 22 formed by the recessed portion 18 deforms to substantially reduce the space. The change in the opening angle formed by the inner surfaces of the recessed portion 18 as described above is configured to be the largest, particularly in the stress concentration portion 28.

[0053] Furthermore, in the present practical embodiment, the recessed part 18 has a groove shape continuous around the entire circumference, and the entire recessed part 18 forms the gap 22. Thus, the concentration of stress in the first elastic body 12 is achieved around the entire circumference, thereby realizing more excellent vibration damping performance.

[0054] Furthermore, the recessed portion 18 opens toward the radially outer side, that is, toward the lateral side with respect to the axial direction, which is the direction of the load action. Thus, when the protruding portion 16 is compressed by the load action in the axial direction and the protruding portion 16 deforms to expand in the direction perpendicular to the axis, the first elastic body 12 deforms to reduce the opening of the recessed portion 18. At this time, stress concentration due to buckling occurs in the stress concentration portion 28 located on the wall of the recessed portion 18, and the stress increases locally, thereby exhibiting excellent vibration reduction performance.

[0055] In addition, since the stress concentration part 28 set to the corner of the recessed part 18 of the present practical embodiment has a trough-shaped curved shape, the stress is more easily concentrated on the stress concentration part 28, so that the vibration damping effect is more effectively achieved due to further concentration of the stress.

[0056] Meanwhile, the fact that the stress in the stress concentration part 28 set to the corner of the wall of the recessed part 18 increases during the load action in the axial direction is further proved by the analysis results obtained by a finite element method of a Fig. 3. Although the output analysis results are displayed in color, they are in Fig. 3 ( Fig. 6, Fig. 21 and Fig. 22) is shown in grayscale, and it is difficult to recognize the difference in voltage level, so a brief explanation is given below. In particular, Fig. 3 shows the stress distribution of the doorstop 10 in a state where the doorstop 10 is compressed in the axial direction between the body frame 24 and the door 26, represented by color coding. Accordingly, the stress at the outer periphery of the protruding part 16, including the proximal end (the lower end) around the corner of the wall of the recessed part 18 (the lower end of the outer peripheral edge of the protruding part 16), is large. Thus, it was confirmed that the stress during the axial direction load is increased at the stress concentration part 28, which is seated on the wall of the gap 22. It should be noted that in Fig. 3 only the right half of the doorstop 10 is illustrated. In addition, Fig. 3 the stress is color-coded according to the magnitude of the stress by the shade, which is closer to blue when the stress is lower and closer to red when the stress is higher.

[0057] By attaching the doorstop 10 having excellent damping capability as described above to the door portion of the vehicle in use with the door 26 closed, the vibration (rattling) of the door 26 is reduced by the doorstop 10. Moreover, by supporting the door 26 through the body frame 24 via the doorstop 10, the closed door 26 further functions as a reinforcing material for the body frame 24, and the strength of the body frame 24 substantially increases, thereby achieving an improvement in the vibration state, an increase in driving performance, and the like of the vehicle. Specifically, the doorstop 10 has a structure in which the first elastic body 12 and the second elastic body 14 are overlapped and arranged in series in the axial direction, which is the direction of load action. In addition, the distal end of the doorstop 10 is formed from the soft second elastic body 14.Thus, the door 26 is flexibly supported by the doorstop 10 to advantageously realize vibration damping of the door 26, integral support thereof with respect to the body frame 24, and the like.

[0058] Furthermore, when the door 26 is closed from the open state, an impact load in the axial direction acts on the doorstop 10, and the doorstop 10 is compressed more strongly in the axial direction. In this case, the displacement amount of the door 26 is limited by the harder first elastic body 12 to prevent the door 26 from hitting the body frame 24. Furthermore, the first elastic body 12 is formed of a high damping material with a large loss factor (tan δ), and the kinetic energy of the door 26 acting on the doorstop 10 is effectively reduced by the damping action of the first elastic body 12. Thereby, the door 26 is supported at an appropriate position relative to the body frame 24, and the door 26 is maintained in a closed state.

[0059] The vibration damping effect of the doorstop 10 is not only effective with respect to a vibration load applied in a state where the door 26 is closed and the doorstop 10 is compressed in the axial direction between the body frame 24 and the door 26, but also effective with respect to an impact load applied to the doorstop 10 when the door 26 is closed from the open state.

[0060] Furthermore, in the doorstop 10 of the present practical embodiment, the first elastic body 12 and the second elastic body 14 are in contact with each other in the axial direction not only at the distal end surface of the protruding part 16 and the upper bottom surface of the depressed part 20, but also at the radially outer side of the protruding part 16 and the depressed part 20. This makes it possible to obtain more excellent load-bearing capacity in the axial direction.

[0061] In addition, in the doorstop 10 of the present practical embodiment, the second elastic body 14, which is softer and superior in shock absorption effect, is formed of a material with a low compression set. Thus, even if a comparatively large compression occurs in the axial direction while the door 26 is continuously closed, the change in the axial dimension of the doorstop 10 due to the compression set of the second elastic body 14 is reduced. On the other hand, with respect to the first elastic body 12 having a larger compression set than that of the second elastic body 14, the axial dimension is larger than that of the second elastic body 14, and the first elastic body 12 is harder than the second elastic body 14.Since the compression generated in the axial direction in the closed state of the door 26 is comparatively small, the change in the axial dimension of the doorstop 10 due to the compression set of the first elastic body 12 is also reduced. Therefore, even if the closed state of the door 26, in which the doorstop 10 is compressed between the body frame 24 and the door 26, is maintained for a long period of time, the compression set of the first elastic body 12 and the second elastic body 14 is suppressed, thereby preventing the axial dimension of the doorstop 10 from changing over time. Thus, the vibration damping effect and the holding ability of the door 26 due to the doorstop 10 are maintained for a long period of time, and the door 26 can be positioned at an appropriate position relative to the body frame 24 during the closing operation of the door 26.

[0062] Fig. 4 and Fig. 5 illustrate a doorstop 30 for a vehicle as a second practical embodiment of a vibration-damping composite body constructed according to the present invention. As in Fig. As shown in Figure 4, the doorstop 30 has a structure in which a first elastic body 32 and a second elastic body 34 overlap each other in the axial direction. In the following description, components and parts that are substantially the same as those in the foregoing first practical embodiment are assigned the same symbols and will not be described in detail.

[0063] Described more specifically, the first elastic body 32 has a shape like a weight as a whole and integrally includes a wave-shaped part 36 having a large diameter, a generally cylindrical shape, and a protruding part 38 protruding upward from the wave-shaped part 36. Furthermore, a groove-shaped depressed part 40 is formed in the lower portion of the protruding part 38 of the first elastic body 32 and opens onto the outer peripheral surface thereof. Due to the deformation of such a depressed part 40, the protruding part 38 of the present practical embodiment is configured such that the upper portion remote from the depressed part 40 has a larger diameter than that of the lower portion in which the depressed part 40 is formed. The constituent material of the first elastic body 32 and the like are similar to those of the first elastic body 12 of the first practical embodiment.

[0064] The second elastic body 34 has a substantially truncated conical shape overall and includes a fixedly installed series arrangement part 42 arranged in series on the upper side of the first elastic body 32, which is the distal end side thereof, and fixed to the upper surface of the protruding part 38 of the first elastic body 32. The second elastic body 34 further includes a fixedly installed parallel arrangement part 44 arranged in parallel to surround the outer periphery of the upper portion of the first elastic body 32 and fixed to the outer peripheral surface of the first elastic body 32.The constituent material of the second elastic body 34 and the like are similar to those of the second elastic body 14 of the first practical embodiment, and the relationship between the hardness of the first elastic body 32 and the hardness of the second elastic body 34 is also similar to that of the first practical embodiment.

[0065] Further, in the second elastic body 34, a depressed portion 45 is formed with the series arrangement portion 42 as the upper bottom and the parallel arrangement portion 44 as the circumferential wall to open downward. Furthermore, a convex portion 46 is provided protruding from the radially inner surface of the depressed portion 45 of the second elastic body 34. The convex portion 46 is provided continuously around the entire circumference, with a cross-sectional shape approximately corresponding to the depressed portion 40 of the first elastic body 32, and the protruding height dimension of the convex portion 46 is smaller than the depth dimension of the depressed portion 40.

[0066] The second elastic body 34 is fixed to cover the upper surface of the first elastic body 32, and the protruding part 38 of the first elastic body 32 is inserted into the depressed part 45 of the second elastic body 34. The protruding part 38 is inserted into the radially inner side of the depressed part 45 over the entire length in the axial direction, which is the protrusion direction, and the outer periphery of the protruding part 38 is surrounded by the second elastic body 34 over the entire length in the axial direction.

[0067] In this way, by covering the upper surface of the first elastic body 32 with the second elastic body 34 and by inserting the protruding part 38 into the depressed part 45, the recessed part 40 of the first elastic body 32 opens onto the overlapping surface with the second elastic body 34, while the convex part 46 of the second elastic body 34 protrudes onto the overlapping surface with the first elastic body 32, and the convex part 46 is inserted into the recessed part 40.

[0068] Further, the convex portion 46 inserted into the recessed portion 40 is overlapped and fixed in a contact state with the upper and lower wall surfaces of the recessed portion 40 and is located away from the radially inner bottom surface of the recessed portion 40 to the radially outer side. Accordingly, a gap 48 extending in the circumferential direction is formed between the distal end surface of the convex portion 46 and the radially inner bottom surface of the recessed portion 40. The gap 48 of the present practical embodiment has an annular shape similar to the gap 22 of the first practical embodiment to be a closed space isolated from the outside.

[0069] The second elastic body 34 is overlapped and fixed in a contact state with a portion of the protruding part 38 of the first elastic body 32 that is remote from the radially inner bottom surface of the recessed part 40, and further fixed to the upper end of the wave-shaped part 36 of the first elastic body 32 and protrudes toward the radially outer side of the wave-shaped part 36. Furthermore, in the doorstop 30 of the present practical embodiment, the first elastic body 32 and the series arrangement part 42 of the second elastic body 34 are arranged in series in the axial direction, while the first elastic body 32 and the parallel arrangement part 44 of the second elastic body 34 are arranged parallel to each other and coaxially.

[0070] As in Fig. As shown in Figure 4, the doorstop 30 having such a structure is attached to the vehicle by the lower end portion of the first elastic body 32 attached to a body frame 24. The first elastic body 32 is attached to the body frame 24, for example, by fixing the lower end portion thereof to the body frame 24, such as by bonding or welding.

[0071] Then, when a load in the axial direction acts on the vehicle-mounted doorstop 30, such as the doorstop 10 of the first practical embodiment, a vibration damping performance based on the vibration reducing effect of the first elastic body 32 is exhibited.

[0072] Specifically, during the application of a load in the axial direction, since the protruding portion 38 of the first elastic body 32 is compressed in the axial direction, the recessed portion 40, which opens toward the radially outer side at the proximal end of the protruding portion 38, deforms such that its upper and lower inner surfaces approach each other in the vertical direction, and the wall of the recessed portion 40 deforms to compress. At this time, a stress concentration portion 28, where stress is concentrated during a load application in the axial direction, is set on the wall of the recessed portion 40, and an excellent vibration reduction effect is exhibited due to an increase in the stress at the stress concentration portion 28.

[0073] In the wall of the recessed part 40 of the present practical embodiment, no clear location of stress concentration is formed by the corner as in the first practical embodiment. In such a case, the stress concentration part 28 is set, for example, at a portion that is an inflection point of the wall surface of the recessed part 40 when it is in a Fig. 4. That is, in the present practical embodiment, the stress concentration part 28 is set toward the radially inner bottom portion of the recessed part 40 at a position where the depth dimension of the recessed part 40 is the largest.

[0074] The stress concentration portion 28 provided to the recessed portion 40 of the present practical embodiment has a curved shape with a certain angle, and with respect to the application of loads in the axial direction, the first elastic body 32 deforms to reduce the opening angle formed by the inner surfaces of the recessed portion 40 at the stress concentration portion 28. Specifically, in the present practical embodiment, during the application of loads in the axial direction, the first elastic body 32 deforms such that the inner surfaces on both the upper and lower sides of the recessed portion 40, sandwiching the stress concentration portion 28, approach each other.Accordingly, during the deformation of the first elastic body 32 due to the action of load in the axial direction, the gap 48 formed by the recessed portion 40 deforms to substantially reduce the space. The variation in the opening angle formed by the inner surfaces of the recessed portion 40 as described above is configured to be the largest, particularly in the stress concentration portion 28.

[0075] Furthermore, the bottom surface of the recessed portion 40 and the protruding distal end surface of the convex portion 46 are spaced apart from each other, and the gap 48 is provided between the recessed portion 40 and the convex portion 46. Thus, the wall surface of the recessed portion 40 is allowed to deform at least at the bottom portion without being restricted by the convex portion 46. This increases the stress in the stress concentration portion 28 located at the bottom of the recessed portion 40 relative to the load action in the axial direction, thereby more advantageously achieving the desired damping effect.

[0076] Furthermore, in the present practical embodiment, the convex part 46 of the second elastic body 34 is fitted into the recessed part 40 of the first elastic body 32, and the upper and lower surfaces of the proximal end portion of the convex part 46 overlap in a contact state with the wall surface of the recessed part 40. With this arrangement, excessive deformation of the wall of the recessed part 40 by the compression spring of the convex part 46 is prevented. Therefore, during the action of load in the axial direction, it is possible to prevent the wall of the recessed part 40 from being damaged by excessive deformation, while effectively achieving the damping effect due to the deformation of the recessed part 40.

[0077] In addition, during the axial direction load action, the upper wall of the recessed portion 40 is vertically compressed between the array portion 42 of the second elastic body 34 and the convex portion 46, and the vertical portion 46 is vertically compressed by the wall of the recessed portion 40. Thus, a further damping effect can also be expected to be achieved.

[0078] The fact that the stress in the stress concentration part 28, which is set to the corner of the wall of the recessed part 40, increases during the action of loads in the axial direction is further verified by the analysis results obtained by a finite element method of a Fig. 6 simulation. That is, according to the stress distribution from Fig. 6, the stress on the wall of the deepest part of the recessed part 40 is large, and it was confirmed that the stress is increased during the load action in the axial direction at the stress concentration part 28, which is located on the wall of the gap 48. It should be noted that Fig. 6 only the right half of the doorstop 30 similar to Fig. 3 of the previous practical embodiment, and the stress illustrated by the color tone is closer to blue when the stress is lower and closer to red when the stress is higher. In the simulation, the analysis results of which are shown in Fig. 6, the body frame 24 is provided with a step, and the body frame 24 is in contact not only with the lower surface of the wave-shaped part 36 of the first elastic body 32, but also with the lower surface of the parallel arrangement part 44 of the second elastic body 34.

[0079] Further, when the door 26 is closed from the open state, an impact load in the axial direction acts on the door stopper 30. Then, as in the first practical embodiment, the displacement of the door 26 relative to the body frame 24 is restricted by the first elastic body 32 at an appropriate position, and the kinetic energy of the door 26 is reduced by the damping action due to elastic deformation of the first elastic body 32.

[0080] Furthermore, when a large load in the pressing direction acts on the doorstop 30 when closing the door 26 or the like, in addition to the series arrangement part 42 of the second elastic body 34 and the first elastic body 32, the parallel arrangement part 44 of the second elastic body 34 is clamped and compressed between the body frame 24 and the door 26. As a result, a harder spring can be achieved in the doorstop 30, and the displacement of the door 26 relative to the body frame 24 is effectively limited. That is, the spring characteristics in the doorstop 30 of the present practical embodiment change gradually according to the magnitude of the action, and when the action is large, a stop effect for limiting the relative displacement between the body frame 24 and the door 26 can be more advantageously achieved. As can be seen from Fig. 4, the series arrangement part 42 and the parallel arrangement part 44 are arranged such that the series arrangement part 42 is compressed in front of the parallel arrangement part 44 during the closing operation of the door 26.

[0081] Fig. Figure 7 illustrates a doorstop 50 for a vehicle as a third practical embodiment of a vibration-damping composite body constructed according to the present invention. The doorstop 50 of the present practical embodiment includes a first elastic body 52 and a second elastic body 54.

[0082] Specifically, the first elastic body 52 is formed of rubber, synthetic resin, or the like and has a generally cylindrical shape. The first elastic body 52 has a groove-shaped recessed portion 56 opening onto the outer peripheral surface thereof and extending around the entire circumference. Meanwhile, the second elastic body 54 is formed of rubber, synthetic resin, or the like and has a generally cylindrical shape with the same diameter as the first elastic body 52.

[0083] The first elastic body 52 and the second elastic body 54 are arranged in series in the axial direction and fixed with the second elastic body 54 overlapped on the upper surface of the first elastic body 52. ​​In the present practical embodiment, the recessed part 56 opening onto the outer peripheral surface of the first elastic body 52 is exposed without being covered by the second elastic body 54, forming a gap 58.

[0084] The doorstop 50 of the present embodiment is mounted on a vehicle by fixing the first elastic body 52 to the body frame 24. Upon closing a door (not shown), the door comes into contact with the second elastic body 54 from the upper side, similar to the previous embodiments, although not shown in the drawing.

[0085] Also similar to the previous practical embodiments, such a doorstop 50 A vibration damping effect is effectively exerted based on the damping effect of the first elastic body 52 with respect to the action of load in the axial direction. Specifically, when the first elastic body 52 is compressed in the axial direction, the stress concentrates and increases at a stress concentration part 28 located on the wall surface of the recessed part 56, thereby effectively exhibiting a damping effect of the first elastic body 52. ​​Moreover, since the recessed part 56 is exposed to the outside, elastic deformation of the first elastic body 52 occurs without being confined in the recessed part 56. This makes it possible to achieve most of the stress at the stress concentration part 28 of the recessed part 56.

[0086] As illustrated in the present practical embodiment, the recessed portion of the first elastic body is not necessarily covered by the second elastic body. Furthermore, the gap formed by the recessed portion may also be an open space exposed to the outside.

[0087] Fig. Figure 8 illustrates a doorstop 60 for a vehicle as a fourth practical embodiment of a vibration-damping composite body constructed according to the present invention. The doorstop 60 of the present practical embodiment includes a first elastic body 62 and a second elastic body 54.

[0088] The first elastic body 62 is formed of a material with higher strength than that of the second elastic body 54 and has a generally cylindrical shape as a whole. The first elastic body 62 has a circular portion 66 opening into the central portion of its upper surface. Meanwhile, the second elastic body 54 has a cylindrical shape approximately corresponding to the shape of the first elastic body 62.

[0089] Then, the second elastic body 54 is overlapped on the upper surface of the first elastic body 62, and the first elastic body 62 and the second elastic body 54 are fixed to each other, thereby providing the doorstop 60. Furthermore, the opening of the recessed portion 66 of the first elastic body 62 is covered by the second elastic body 54, and a circular gap 68 formed by the recessed portion 66 is formed between the overlapping surfaces of the first elastic body 62 and the second elastic body 54. In the present practical embodiment, a corner of the lower end of the outer peripheral edge of the wall of the recessed portion 66 forms a stress concentration portion 28.

[0090] By attaching the first elastic body 62 to, for example, an automobile body frame 24, the doorstop 60 having such a structure is interposed between the body frame 24 and a door (not shown). With this arrangement, the body frame 24 and the door are held in a positionally appropriate relative position and are connected to each other in a vibration-damping manner, while cushioning a shock when the door is closed from the open state.

[0091] Furthermore, in the doorstop 60 constructed according to the present practical embodiment, the stress concentration portion 28, where a large stress is generated with respect to the load action in the axial direction, is located on the wall of the gap 68 formed by the recessed portion 66 of the first elastic body 62. Due to the large stress concentrated in the stress concentration portion 28, the energy damping effect of the first elastic body is advantageously exhibited, thereby achieving excellent vibration damping performance.

[0092] As shown in the present practical embodiment, in the case where the depressed part constituting the stress concentration part is provided to the overlapping portion of the first elastic body and the second elastic body, the depressed part is not necessarily limited to that provided at the corner of the proximal end of the protruding part.

[0093] Fig. Fig. 9 illustrates a doorstop 70 for a vehicle as a fifth practical embodiment of the vibration-damping composite body constructed according to the present invention. The doorstop 70 of the present practical embodiment includes a first elastic body 72 and a second elastic body 74.

[0094] Specifically, the first elastic body 72 is formed of rubber, synthetic resin, or the like and has a generally cylindrical shape. The first elastic body 72 has a groove-shaped recessed portion 76 opening onto the outer peripheral surface thereof and extending around the entire circumference.

[0095] The second elastic body 74 is formed of rubber, synthetic resin, or the like and has a generally cylindrical shape. The inner diameter dimension of the second elastic body 74 corresponds to the outer diameter dimension of the first elastic body 72. Furthermore, a convex part 78 is formed integrally with the radially inner surface of the second elastic body 74 to protrude toward the radial inside. The protruding height dimension of the convex part 78 is smaller than the depth dimension of the depressed part 76 of the first elastic body 72. The convex part 78 of the present practical embodiment is provided with a generally constant cross-sectional shape continuously around the entire circumference.

[0096] The first elastic body 72 and the second elastic body 74 are arranged parallel to each other and coaxially, the first elastic body 72 is inserted into the inner bore of the second elastic body 74, and the outer peripheral surface of the first elastic body 72 and the radially inner surface of the second elastic body 74 are fixed to each other. That is, the doorstop 70 of the present practical embodiment is configured such that its radially inner portion is formed by the first elastic body 72 and its outer peripheral portion is formed by the second elastic body 74.

[0097] Further, the convex part 78 of the second elastic body 74 is inserted into the depressed part 76 of the first elastic body 72, and the proximal end portion of the convex part 78 is overlapped in a contact state with the upper and lower wall surfaces of the depressed part 76. Moreover, the distal end surface of the convex part 78 is located away from the radially inner bottom surface of the depressed part 76 to the radially outer side, so that a gap 79 is formed between the distal end surface of the convex part 78 and the radially inner bottom surface of the depressed part 76. Note that the proximal end portion of the convex part 78 and the upper and lower wall surfaces of the depressed part 76 may be fixed to each other, or alternatively, may be in contact with each other in a non-stick manner.

[0098] The doorstop 70 of the present embodiment is mounted on a vehicle by fixing the first elastic body 72 to a body frame 24. By closing a door (not shown), the door comes into contact with the second elastic body 74 from the upper side, similar to the previous embodiments, while not shown in the drawing.

[0099] Also similar to the previous practical embodiments, such a doorstop 70 A vibration damping effect is effectively exerted based on the damping effect of the first elastic body 72 with respect to load action in the axial direction. Specifically, when the first elastic body 72 is compressed in the axial direction, the stress concentrates and increases at a stress concentration part 28 located on the radially inner bottom portion of the recessed part 76, thereby effectively exhibiting a damping effect of the first elastic body 72. Moreover, since the stress concentration part 28 is located on the wall of the gap 79 of the first elastic body 72, elastic deformation of the first elastic body 72 occurs at the stress concentration part 28 without being restricted by the second elastic body 74 or the like. This makes it possible to achieve most of the stress at the stress concentration part 28.

[0100] As shown in the present practical embodiment, the first elastic body and the second elastic body are not necessarily limited to the placement arranged in series in the direction of load action, but may be placed parallel to each other to be arranged coaxially, for example.

[0101] Fig. 10 to 12 illustrate a stop rubber 80 for a vibration damping device as a sixth practical embodiment of the vibration damping composite body constructed according to the present invention. As in Fig. 10 and Fig. 12, the stop rubber 80 according to the present practical embodiment comprises a first elastic body 82 and a second elastic body 84. In the present practical embodiment, the vertical direction generally refers to the vertical direction in Fig. 10, the left-right direction refers to the left-right direction in Fig. 10 and the forward-backward direction refers to the vertical direction in Fig. 11.

[0102] More specifically, the first elastic body 82 is formed of rubber, synthetic resin or the like and has a general plate shape extending in a direction as shown in Fig. 11. Furthermore, as shown in Fig. 10 and Fig. As shown in FIG. 12, the first elastic body 82 includes protruding portions 86 protruding on the upper surface and extending straight in the front-back direction, and recessed portions 88 opening toward the lateral left-right side on opposite left-right sides of the proximal end of the protruding portion 86. In the present practical embodiment, a plurality of the protruding portions 86 are arranged parallel to each other at a predetermined distance in the left-right direction, and the recessed portions 88 are formed on opposite left-right sides of each protruding portion 86. With respect to the protruding portions 86 provided on opposite left-right ends, the recessed portion 88 is formed only on the inner left-right sides of the proximal end of the protruding portion 86.

[0103] Further, the first elastic body 82 has three integrally formed mounting protrusions 90, 90, 90 projecting downward. The mounting protrusion 90 has a generally cylindrical shape with a small diameter overall and has an integrally formed locking portion 92 projecting radially outward at its axially central portion. The mounting protrusion 90 is smaller in diameter on the distal side of the locking portion 92 than on the proximal side thereof to be easily inserted into a locking hole 110 of an inner holder 106, which will be described later.

[0104] The second elastic body 84 is formed of rubber, synthetic resin, or the like and has a plate shape of approximately the same planar shape as the first elastic body 82. Furthermore, the second elastic body 84 has a groove-shaped depressed portion 94 opening onto the lower surface and extending in the front-back direction. The depressed portion 94 extends straight with a generally constant rectangular cross-section, and compared with the protruding portion 86 of the first elastic body 82, its left-right dimension is larger, while its vertical dimension is the same as or slightly smaller. Moreover, in the present practical embodiment, a plurality of the depressed portions 94, which correspond to the protruding portions 86, are arranged parallel to each other at a predetermined distance in the left-right direction.

[0105] The first elastic body 82 and the second elastic body 84 overlap in the vertical direction and are fixed to each other. Furthermore, the protruding part 86 of the first elastic body 82 is inserted into the depressed part 94 of the second elastic body 84, and the distal end surface of the protruding part 86 and the upper bottom surface of the depressed part 94 overlap in a contact state and are fixed to each other.

[0106] Here, the left-right side surfaces of the protruding part 86 of the first elastic body 82 and the left-right side wall surfaces of the depressed part 94 of the second elastic body 84 are spaced apart from each other in the left-right direction. Accordingly, a gap 96 extending straight in the front-back direction is formed between the protruding part 86 and the left-right side wall surfaces of the depressed part 94. The gap 96 is provided on opposite left-right sides of the protruding part 86, and a part of the gap 96 is formed by the depressed part 88 of the first elastic body 82. Note that the gap 96 of the present practical embodiment is formed by an open space whose opposite front-back ends are exposed to the outside.

[0107] As in Fig. 13 and Fig. 14, a bump stop rubber 80 having such a structure is used by being attached to a vibration damping device 98, such as an engine mount. The vibration damping device 98 has a structure in which a first fastening member 100 and a tubular second fastening member 102 are elastically connected by an elastic main body 104 made of rubber. Furthermore, an inner bracket 106 is attached to the first fastening member 100, while an outer bracket 108 is attached to the outside of the second fastening member 102.

[0108] Furthermore, an inner bracket 106 is inserted through the second fastening member 102 and the outer bracket 108 and extends as far as the lower side of the outer bracket 108. Accordingly, the inner bracket 106 and the outer bracket 108 are opposed to each other at a predetermined distance in the vertical direction. By attaching the inner bracket 106 and the outer bracket 108 to one or the other of components constituting a vibration transmission system, such as an engine and a vehicle body, the components constituting the vibration transmission system are configured to be connected in a vibration-damping manner via the vibration damping device 98, for example.

[0109] Then, the stopper rubber 80 is overlapped on the surface of the inner bracket 106 opposite to the outer bracket 108. By inserting the mounting projections 90 of the stopper rubber 80 through the locking holes 110 formed in the inner bracket 106 and locking the locking pieces 92 with the opening peripheral edges of the locking holes 110, the stopper rubber 80 is attached to the inner bracket 106.

[0110] With the vibration damping device 98 mounted on the vehicle, when a large impact load is applied in the vertical direction, which is the axial direction, and the first fastening member 100 and the second fastening member 102 are largely displaced apart from each other in the vertical direction, the opposing surfaces of the inner bracket 106 and the outer bracket 108 approach each other in the vertical direction and come into contact with each other via the stopper rubber 80. At this time, the vibration damping device 98 is provided with a rebound stopper for limiting an amount of displacement between the first fastening member 100 attached to the inner bracket 106 and the second fastening member 102 attached to the outer bracket 108 from each other in the vertical direction.

[0111] Furthermore, by clamping the stopper rubber 80 between the inner bracket 106 and the outer bracket 108 in the vertical direction, the protruding portion 86 of the first elastic body 82 is compressed in the vertical direction. As a result, a stress in a stress concentration portion 28 located at the wall of the gap 96 formed by the recessed portion 88 of the first elastic body 82 increases, thereby advantageously achieving a damping effect of the first elastic body 82. The stress concentration portion 28 of the present practical embodiment is located at the corner of the proximal end of the protruding portion 86.

[0112] Furthermore, the stress concentration part 28 faces the gap 96, and the deformation of the stress concentration part 28 is not restricted by the second elastic body 84. Therefore, a large stress can be generated at the stress concentration part 28, making it possible to achieve a greater damping effect relative to the action in the vertical direction.

[0113] Furthermore, in the present practical embodiment, by providing a plurality of the stress concentration parts 28, the stress of the first elastic body 82 is dispersed to some extent with respect to the impact, thereby achieving an effective damping effect while improving the durability.

[0114] Fig. Fig. 15 illustrates a vibration damping device 122, including a stopper rubber 120, which is a seventh practical embodiment of the vibration damping composite body according to the present invention. The tubular vibration damping device 122 has a structure in which an inner shaft member 124 and an outer tube member 126 are elastically connected by an elastic main body 128 made of rubber. In the description of the present practical embodiment, the axial direction generally refers to the direction perpendicular to the plane of the side in Fig. 15, the vertical direction refers to the vertical direction in Fig. 15 and the left-right direction refers to the left-right direction in Fig. 15.

[0115] Specifically, the inner shaft member 124 is a high-strength member made of metal, synthetic resin, or the like, and extends in the axial direction with a cross-sectional shape that narrows downward in the left-right direction. Furthermore, a bolt hole 130 penetrates the central portion of the inner shaft member 124 in the axial direction. Furthermore, a concavity 131 opening upward is formed at the upper end of the inner shaft member 124. On the other hand, the outer tubular member 126 is a high-strength member made of metal, synthetic resin, or the like, and has a thin-walled, generally round, tubular shape with a large diameter.

[0116] The inner shaft member 124 is disposed on the radially inner side of the outer tube member 126, and the inner shaft member 124 and the outer tube member 126 are elastically connected by the rubber elastic main body 128. The rubber elastic main body 128 extends from the left-right side surfaces of the inner shaft member 124 to slope downward toward the left-right outside, and the opposite left-right ends of the rubber elastic main body 128 are fixed to the radially inner surface of the outer tube member 126.

[0117] Here, the stopper rubber 120 is arranged on the upper side of the inner shaft member 124. The stopper rubber 120 has a structure in which a first elastic body 132 and a second elastic body 134 overlap each other in the vertical direction.

[0118] The first elastic body 132 is formed integrally with or separately from the elastic main body 128 made of rubber and fixed to the inner surface of the concavity 131 opening onto the upper surface of the inner shaft member 124. Further, the first elastic body 132 is provided with a protruding portion 136 projecting upward from the left-right central portion thereof, and a recessed portion 138 opening toward the lateral side and above is formed at the proximal end of the protruding portion 136. The protruding portion 136 of the present practical embodiment extends straight in the axial direction with a generally constant rectangular cross section.

[0119] The second elastic body 134 is a separate component from the first elastic body 132 and is made of rubber, resin elastomer, or the like, which has lower damping than the first elastic body 132. Furthermore, the second elastic body 134 is provided with a groove-shaped depressed portion 140 opening onto the lower surface and extending straight in the axial direction. In a preferred application, the second elastic body 134 is formed of a material that is softer than the first elastic body 132.

[0120] Then, the second elastic body 134 is overlapped and fixed to the upper surface of the first elastic body 132 fixed to the inner shaft member 124 to form the stopper rubber 120 of the present practical embodiment. Further, the protruding part 136 of the first elastic body 132 is inserted into the depressed part 140 of the second elastic body 134, and the distal end surface of the protruding part 136 and the upper bottom surface of the depressed part 140 overlap each other in a contact state. Furthermore, the left-right side surfaces of the protruding part 136 and the left-right side wall surfaces of the depressed part 140 are opposite to each other to be spaced apart from each other in the left-right direction.Accordingly, a gap 142 is formed between the left-right side surfaces of the protruding part 136 and the left-right side wall surfaces of the depressed part 140 to penetrate in the axial direction. A part of the gap 142 is formed by the recessed part 138 of the first elastic body 132, and at a portion of the wall of the gap 142 formed by the corner of the recessed part 138, a stress concentration part 28 is formed, which is subjected to increased stress during a load application, which will be described later.

[0121] The stop rubber 120 is disposed below the radially inner surface of the outer tubular member 126 at a predetermined distance. The radially inner surface of the outer tubular member 126 is covered by a rubber cover layer 144 formed integrally with the rubber elastic main body 128, and the stop rubber 120 is located downward from the radially inner surface of the rubber cover layer 144.

[0122] In the tubular vibration damping device 122 having such a structure, when a large impact load is applied in the vertical direction via the inner shaft member 124 and the outer tube member 126 and the inner shaft member 124 is displaced upward relative to the outer tube member 126, the inner shaft member 124 and the outer tube member 126 come into contact with each other through the stopper rubber 120. At this time, an upper stopper for limiting an amount of relative displacement between the inner shaft member 124 and the outer tube member 126 is formed by including the stopper rubber 120.

[0123] Here, in the stopper rubber 120, the stress is concentrated on the stress concentration part 28, so that the damping effect of the first elastic body 132 is largely exhibited, thereby achieving an excellent shock absorption effect. At this time, in the upper stopper, a shock, impact noise, or the like caused by the contact between the inner shaft member 124 and the outer tube member 126 is reduced based on the energy damping effect of the stopper rubber 120.

[0124] Meanwhile, Fig. 16 shows a tubular vibration damping device 150 according to another embodiment of the present invention. Specifically, the tubular vibration damping device 150 has a structure in which an inner shaft member 152 and an outer tube member 126 are elastically connected by an elastic main body 154 made of rubber.

[0125] The inner shaft member 152 has a generally cylindrical shape and is penetrated in the axial direction by a bolt hole 130. The inner shaft member 152 is arranged to be inserted into the outer tube member 126, and the inner shaft member 152 and the outer tube member 126 are elastically connected by the elastic main body 154 made of rubber.

[0126] The rubber elastic main body 154 has a generally round tubular shape as a whole, and its radially inner surface is fixed to the outer peripheral surface of the inner shaft member 152, while its outer peripheral surface is fixed to the radially inner surface of the outer tube member 126. Furthermore, upper and lower bore portions 156, 158 are formed on the upper and lower sides, respectively, of the rubber elastic main body 154, sandwiching the inner shaft member 152 to penetrate the rubber elastic main body 154 in the axial direction. The upper bore portion 156 extends circumferentially from a position away from the inner shaft member 152 to the radially outer side and extends over a length less than half the circumference.On the other hand, the lower bore part 158 ​​extends downward in the left-right direction at a position away from the inner shaft member 152, and its central left-right portion is expanded downward.

[0127] Further, a stopper rubber 160, which is an eighth practical embodiment of the vibration-damping composite body according to the present invention, is arranged on the radially outer side of the upper bore part 156. The stopper rubber 160 has a structure in which a first elastic body 162 and a second elastic body 164 overlap in the vertical direction.

[0128] The first elastic body 162 is formed integrally with the elastic main body 154 made of rubber, and a plurality of protruding portions 166 protruding toward the radially outer side are provided adjacent to each other in the circumferential direction. The outer circumferential surface of the first elastic body 162 is made corrugated by the protruding portions 166. Furthermore, groove-shaped recessed portions 168 opening toward the radially outer side and extending in the axial direction are formed between the circumferentially adjacent protruding portions 166, 166.

[0129] The second elastic body 164 is a separate member from the first elastic body 162 and the rubber main elastic body 154 and has a curved plate shape extending entirely in the circumferential direction. The upper surface of the second elastic body 164 has an arcuate curved surface that conforms to the radially inner surface of the outer tubular member 126, while the lower surface has a plurality of depressed portions 170 formed adjacent to each other in the circumferential direction. The depressed portion 170 has a circumferential width dimension larger than that of the protruding portion 166 of the first elastic body 162, while having a depth dimension approximately equal to or slightly smaller than the height dimension of the protruding portion 166.

[0130] Then, the second elastic body 164 is inserted between the first elastic body 162 and the outer tubular member 126, and the outer peripheral surface of the second elastic body 164 is fixed to the radially inner surface of the outer tubular member 126. This configuration provides the stopper rubber 160 in which the first elastic body 162 and the second elastic body 164 overlap in the radial direction.

[0131] Further, the protruding portion 166 of the first elastic body 162 is inserted into the depressed portion 170 of the second elastic body 164 such that the side surface of the protruding portion 166 and the side inner surface of the depressed portion 170 are oppositely positioned to be away from each other. Accordingly, a gap 172 extending in the axial direction is formed between the protruding portion 166 and the wall of the depressed portion 170, including a recessed portion 168. Furthermore, a stress concentration portion 28 is located in the wall of the gap 172 formed by the first elastic body 162, which is subjected to increased stress during the application of loads in the vertical direction, which will be described later.The stress concentration part 28 of the present practical embodiment is seated at a corner provided in the wall of the recessed part 168 at the proximal end of the projecting part 166.

[0132] In the tubular vibration damping device 150 having such a structure, when a large impact load is applied in the vertical direction via the inner shaft member 152 and the outer tube member 126 and the inner shaft member 152 is displaced upward relative to the outer tube member 126, the inner shaft member 152 and the outer tube member 126 come into contact with each other through the stopper rubber 160. At this time, an upper stopper for limiting an amount of relative displacement between the inner shaft member 152 and the outer tube member 126 is formed by including the stopper rubber 160.

[0133] In the stopper rubber 160 constructed according to the present practical embodiment, the stress is concentrated on the stress concentration part 28, so that the damping effect of the first elastic body 162 is largely exhibited. Thus, in the upper stopper, a shock, a knocking noise, or the like caused by indirect contact between the inner shaft member 152 and the outer tube member 126 is reduced based on the energy damping effect of the stopper rubber 160.

[0134] The Fig. 15 and Fig. The tubular vibration damping devices 122, 150 shown in Fig. 16 may be provided with brackets or the like on the inner shaft members 124, 152 and the outer tube members 126, 126 as needed. As a concrete example, the tubular vibration damping devices 122, 150 may be used by inserting them into a tubular part provided to a rod end of a torsion bar, and the like.

[0135] Fig. 17 to 20 illustrate a doorstop 180 for a vehicle according to a ninth practical embodiment of the present invention. The doorstop 180, which is a metal spring-equipped vibration-damping composite body, has a structure in which a vibration-damping composite body 182 is fixed to a metal spring 184.

[0136] The vibration-damping composite body 182 includes a first elastic body 186 and a second elastic body 188, and has approximately the same construction as the doorstop 30 shown in the second practical embodiment. However, in the present practical embodiment, the first elastic body 186 has an approximately oval columnar shape, and the second elastic body 188 has an approximately oval truncated cone shape. That is, the vibration-damping composite body 182 has a construction in which the doorstop 30 is elongated in a diametrical direction and has an approximately oval shape when viewed in the vertical direction. Furthermore, a fixing part 190 extending toward the radially outer side is integrally formed with the lower end of the first elastic body 186.

[0137] The metal spring 184 is a metal disc spring having a construction in which a blank metal plate is folded at a bending part 192. As shown in Fig. As shown in Figure 19, a first plate-shaped portion 194 having a nearly flat plate shape is provided on one side of the bent portion 192 having a curved plate shape, and a second plate-shaped portion 196 having a nearly flat plate shape is provided on the other side thereof. Furthermore, the second plate-shaped portion 196 has fixedly installed attachment portions 198, 198 extending from the end opposite the bent portion 192 to both the left and right sides. Each of the attachment portions 198, 198 is penetrated by a bolt hole 200.

[0138] The first plate-shaped part 194 and the second plate-shaped part 196, which are arranged to face each other vertically, shift relative to each other along with a relative angle change due to elastic deformation of the bending part 192, whereby the metal spring 184 is configured to function as a spring. In the present practical embodiment, the first plate-shaped part 194 and the second plate-shaped part 196 are arranged to be relatively inclined by a predetermined inclination angle θ satisfying 0° < θ < 90°, and the metal spring 184 deforms so that θ approaches 0° due to the action of a load. In the metal spring 184 in the initial state where no load is applied, the relative inclination angle θ of the first plate-shaped part 194 and the second plate-shaped part 196 is preferably 30° or less.

[0139] The first elastic body 186 of the vibration-damping composite body 182 is fixed to the upper surface of the first plate-shaped part 194 of the metal spring 184, and the metal spring 184 is provided in series below the vibration-damping composite body 182. In the present practical embodiment, since the fixing part 190 is formed integrally with the lower end of the first elastic body 186, a large area for fixing the first elastic body 186 to the metal spring 184 is obtained, thereby improving the adhesion strength. The fixing method of the first elastic body 186 and the metal spring 184 is not particularly limited, but various publicly known methods, such as bonding or welding, can be adopted.Furthermore, in the present practical embodiment, after the vibration-damping composite body 182 is formed by combining the first elastic body 186 and the second elastic body 188, the first elastic body 186 is fixed to the metal spring 184. However, it would also be acceptable that, for example, after the first elastic body 186 is fixed to the metal spring 184 in its single state, the second elastic body 188 is combined with the first elastic body 186 such that the vibration-damping composite body 182 is formed on the metal spring 184.

[0140] As in Fig. As shown in Fig. 19, the doorstop 180 according to the present practical embodiment is configured with such a structure that the second plate-shaped part 196 of the metal spring 184 is attached to a vehicle body frame 24, which is a component to be damped, by inserting bolts (not shown) through the bolt holes 200, 200 of the metal spring 184. At this time, the doorstop 180 is disposed between the body frame 24, which is a main component of a vibration transmission system, and a door 26 serving as a vehicle door. When the door 26 is closed, the door 26 comes into contact with the vibration-damping composite body 182, and the doorstop 180 will be in a compressed state between the body frame 24 and the door 26, with the door 26 closed.

[0141] When the door 26 is closed with the doorstop 180 mounted on the vehicle, due to the door 26 coming into contact with the vibration-damping composite body 182, a load in the approximately vertical direction acts on the vibration-damping composite body 182, thereby exhibiting a vibration-damping effect based on a vibration-reducing effect of the first elastic body 186. Specifically, a reducing effect is effectively achieved by the first elastic body 186, which is formed of a high-damping material and in which a stress-concentrating part 28 is fitted on the wall of a recessed part 40.

[0142] Meanwhile, the fact that the stress in the stress concentration part 28, which is set to the corner of the wall of the recessed part 40, increases during the load action in the vertical direction is further explained by the result of a Fig. 21 simulation. That is, according to the simulation result from Fig. 21, it was confirmed that the stress on the wall of the deepest part of the recessed part 40 on the left side of the drawing was increased. It should be noted that in Fig. 21 and in Fig. 22, which will be described later, which illustrate the simulation result, the magnitude of the distortion is characterized by the color tone, which is closer to blue when the stress is lower and closer to red when the stress is higher. It should also be noted that the stress distributions in Fig. 21 and Fig. 22 shows the simulation results in the case that the doorstop was compressed to the extent that the relative inclination angle of the first plate-shaped part 194 and the second plate-shaped part 196 in the metal spring 184 was reduced by 4°.

[0143] Furthermore, since the direction of application of the main load relative to the doorstop 180 is approximately vertical, the vibration-damping composite body 182 and the metal spring 184 are arranged in series in the direction of load application. With this arrangement, the metal spring 184 undergoes elastic deformation during the application of the load, along with an angular change of the first plate-shaped part 194 and the second plate-shaped part 196. Therefore, for example, when the door 26 is kept closed and the stationary load continuously acts on the doorstop 180, by preferentially subjecting the metal spring 184 to elastic deformation, permanent elongation of the vibration-damping composite body 182 is prevented. This can achieve an improvement in the durability of the vibration-damping composite body 182, the stabilization of vibration-damping properties thereof, and the like.

[0144] In addition, the Fig. The simulation result shown in Figure 22 demonstrates that the metal spring 184 is subjected to elastic deformation during the load application. This means that Fig. 22, it was found that the stress on the metal spring 184 during the application of the load was concentrated on the flexure 192, and the metal spring 184 was subjected to elastic deformation at the flexure 192. Thus, in the doorstop 180 of the present practical embodiment, the load is borne not only by the vibration-damping composite body 182 but also by the metal spring 184.

[0145] Furthermore, the spring constant of the metal spring 184 increases linearly as the amount of deformation increases. Therefore, during the application of a large load, which acts when the door 26 is closed or the like, elastic deformation of the vibration-damping composite body 182 occurs from the state where the metal spring 184 has deformed to a certain extent, thereby effectively achieving the vibration-damping effect of the vibration-damping composite body 182.

[0146] Furthermore, the angular change of the first plate-shaped part 194 and the second plate-shaped part 196 in the metal spring 184 occurs around a position different from the hinge (not shown) connecting the body frame 24 and the door 26. Thus, as the door 26 moves around the hinge from the contact state with the vibration-damping composite body 182 to the closing direction, the contact position of the door 26 with respect to the vibration-damping composite body 182 and the applied direction of the load change. Then, for example, by the door 26 coming into contact with the corner of the upper end of the vibration-damping composite body 182, the stress of the vibration-damping composite body 182 due to the load applied from the door 26 is more easily concentrated on the stress concentrating part 28, thereby more effectively achieving the damping effect of the first elastic body 186.

[0147] Specifically, in the present practical embodiment, the metal spring 184 is subjected to elastic deformation, and the direction of the load action changes. Thus, when the load acts on the outer peripheral corner of the distal end of the composite vibration damping body 182, the outer peripheral end of the upper part of the protruding part 38 is pressed downward, and deformation such as compression is more likely to occur on the inner surface of the recessed part 40 opening onto the outer peripheral surface of the protruding part 38. As a result, a larger stress is generated partially in the circumferential direction in the stress concentration part 28 located on the inner surface of the recessed part 40, thereby exhibiting the damping effect of the first elastic body 186 much more strongly.

[0148] Furthermore, since the metal spring 184 is provided in series with the vibration damping composite body 182 in the direction of load action, the size of the doorstop 180 in the direction of load action can also be easily adjusted by the metal spring 184. That is, when attempting to adjust the size of the doorstop 180 by the first and second elastic bodies 186, 188, the spring properties, damping capacity, compression set, and the like are greatly affected, and a high degree of adjustment is necessary to realize the required properties. However, for the metal springs 184, it is not necessary to consider damping and permanent strain, so the properties are easily adjusted at the time of size adjustment. Therefore, by adjusting the size and shape of the metal spring 184, it is easy to adjust the size of the doorstop 180 while realizing the required properties.Thus, even if the distance between the body frame 24 and the door 26 is large, if the first and second elastic bodies 186, 188 are held at a position close to the door 26 by the metal spring 184, it is possible to effectively retain a contact reaction force or the like exerted by the door stopper 180 on the door 26 when the door 26 is closed. This further makes it possible to adopt a common vibration-damping composite body 182 for door structures with different pitches.

[0149] Fig. Fig. 23 illustrates a stopper member 210 as the tenth practical embodiment according to the present invention in a state in which it is attached to a vibration damping device 212. In the following description, the vertical direction generally refers to the vertical direction in Fig. 23, which is the direction of action of the main load.

[0150] The stop member 210 includes a metal spring 214. The metal spring 214 is a disc spring having a structure in which a blank metal plate is folded at a bent portion 216. A first plate-shaped portion 218 is provided on one side of the bent portion 216 with a curved plate shape, and a second plate-shaped portion 220 is provided on the other side thereof.

[0151] The first plate-shaped part 218 has a shape of an approximately flat plate and extends from the upper end of the bending part 216 to the radially inner side of the vibration damping device 212, while rising upward as it approaches the radially inner side of the vibration damping device 212. The second plate-shaped part 220 has a shape of an approximately flat plate and extends from the lower end of the bending part 216 to the radially inner side of the vibration damping device 212, while spreading approximately perpendicular to the vertical direction. In addition, the second plate-shaped part 220 has a fixedly installed clinch piece 222 which serves as an attachment part and is in the width direction (the direction perpendicular to the plane of the side in Fig. 23) protrudes on both sides. By clinching the clinch piece 222 to a second fastening element 244, the metal spring 214 is fixed to the second fastening element 244.

[0152] In addition, a first elastic body 224 is fixed to the metal spring 214. The first elastic body 224 is fixed to both the upper and lower surfaces of the first plate-shaped part 218 of the metal spring 214, and the first elastic body 224, which is fixed to the lower surface of the first plate-shaped part 218, extends to the bending part 216 and one of the surfaces of the second plate-shaped part 220 to be fixed thereto. Furthermore, the first elastic body 224, which is fixed to the upper surface of the first plate-shaped part 218, has two recessed grooves 226, 226 serving as recessed parts formed parallel to each other. The recessed grooves 226, 226 extend in the width direction of the first plate-shaped part 218 (the direction perpendicular to the plane of the side in Fig. 23) straight, while opening onto the upper surface of the first elastic body 224. The cross section of the two recessed grooves 226, 226, which is perpendicular to the groove longitudinal direction (the direction perpendicular to the plane of the side in Fig. 23) is generally rectangular. Further, between the recessed grooves 226, 226 of the first elastic body 224, a protruding part 228 is provided, separating the recessed grooves 226, 226, and the proximal end portion of the protruding part 228, which is a corner of the recessed grooves 226, 226, serves as a stress concentration part 28 in the present practical embodiment. The side walls of the recessed grooves 226, 226, which are opposite to the protruding part 228, form interlocking protrusions 230, 230, each projecting at a height substantially identical to that of the protruding part 228.

[0153] In addition, a second elastic body 232 is attached to the first elastic body 224. The second elastic body 232 is a rubber elastic body having a rectangular plate shape, and its upper surface is substantially flat, while its lower surface has convex parts 234, 234 that correspond to the recessed grooves 226, 226 of the first elastic body 224. The convex parts 234, 234 extend in the width direction of the first plate-shaped part 218 (the direction perpendicular to the plane of the side in Fig. 23) and the distance between the convex parts 234, 234 is greater than the width dimension of the protruding part 228 of the first elastic body 224.

[0154] The second elastic body 232 is overlapped from above with respect to the first elastic body 224, which is fixed to the upper surface of the first plate-shaped part 218 of the metal spring 214, and the convex parts 234, 234 are inserted into the corresponding recessed grooves 226, 226 of the first elastic body 224. In the present practical embodiment, the opposite side surfaces of the convex parts 234, 234 are spaced from both side surfaces of the protruding part 228 of the first elastic body 224, and gaps 236 are formed between the two side surfaces of the protruding part 228 of the first elastic body 224 and the opposite side surfaces of the convex parts 234, 234 of the second elastic body 232. With this configuration, a stress concentration part 28 is provided on the wall of the gap 236 of the first elastic body 224.It should be noted that the protruding part 228 protruding onto the overlapping surface of the first elastic body 224 with the second elastic body 232 is inserted between the convex parts 234, 234 of the second elastic body 232 and overlaps the protruding distal end surface of the protruding part 228 with the second elastic body 232.

[0155] Meanwhile, the other side surfaces of the convex portions 234, 234 are pressed against the side surfaces of the interlocking projections 230, 230 of the first elastic body 224, and by fitting the convex portions 234, 234 into the interlocking projections 230, 230, the first elastic body 224 and the second elastic body 232 are secured. Furthermore, in the present practical embodiment, an engaging recess 238 is formed on the outer side of the convex portion 234, and by also fitting the engaging projection 230 into the engaging recess 238, the first elastic body 224 and the second elastic body 232 are secured.

[0156] A vibration damping composite body 240 of the present practical embodiment includes the first elastic body 224 fixed to the upper surface of the first plate-shaped part 218 and the second elastic body 232 attached thereto. Furthermore, the first elastic body 224 is formed of a material having higher damping than that of the second elastic body 232 and formed of a hard material having a larger spring constant than that of the second elastic body 232. As a constituent material of the first elastic body 224 and the second elastic body 232, for example, the material similar to that in the first practical embodiment is preferably used.

[0157] The stop member 210 having such a construction is attached to the vibration damping device 212. The vibration damping device 212 is a so-called cup-shaped vibration damping device and has a construction in which a first fastening member 242 and the second fastening member 244 are elastically connected by an elastic main body 246 made of rubber. Furthermore, an inner bracket 248, which is Fig.23 protrudes to the left is attached to the first fastening member 242, and a portal-shaped outer bracket 250 is attached to the second fastening member 244. The outer bracket 250 is arranged flush with the upper side of the first fastening member 242. Furthermore, the second fastening member 244 is provided with a flange-shaped part 252 protruding toward the radially outer side at the upper end portion around the entire circumference, and a stopper receiver 254 is provided at a part of the flange-shaped part 252 in the circumferential direction where the protruding dimension toward the radially outer side is partially increased. The specific construction of the vibration damping device 212 is not particularly limited, but various publicly known constructions are usable.For example, a fluid-filled vibration damping device having a fluid chamber with a non-compressible fluid or liquid sealed therein may be used.

[0158] Then, the second plate-shaped part 220 of the metal spring 214 constituting the stopper member 210 is overlapped from above onto the stopper receptacle 254 provided for the second fastening member 244 of the vibration damping device 212. By clinching the clinch piece 222 of the second plate-shaped part 220 to be wound onto the stopper receptacle 254, the metal spring 214 of the stopper member 210 is secured to the second fastening member 244 of the vibration damping device 212. However, the fastening embodiment of the stopper member 210 to the vibration damping device 212 is merely an example and is not particularly limited.As a concrete example, it would also be acceptable to provide a locking structure between the second plate-shaped part 220 of the metal spring 214 and the stopper receptacle 254 of the second fastening member 244, and to secure the metal spring 214 and the second fastening member 244 by locking. Furthermore, the metal spring 214 and the second fastening member 244 may be fixed, for example, by bonding or welding, or the metal spring 214 may be integrally formed with a part of the second fastening member 244. Furthermore, the stopper member 210 may be further provided on the inner bracket 248 side.

[0159] While the stopper member 210 is mounted on the vibration damping device 212, the upper end portion of the stopper member 210 formed by the second elastic body 232 is disposed below the inner bracket 248 at a predetermined distance (stop distance). That is, while the stopper member 210 is mounted on the vibration damping device 212, the first plate-shaped part 218 and the second plate-shaped part 220 of the metal spring 214, as well as the vibration-damping composite body 240 attached to the metal spring 214, are vertically disposed between the inner bracket 248 and the stopper receptacle 254 of the second fastening member 244.

[0160] When vibration in the vertical direction is applied via the first fastening member 242 and the second fastening member 244 of the vibration damping device 212, and the first fastening member 242 and the second fastening member 244 largely displace in the direction of approaching each other in the vertical direction, the inner bracket 248 attached to the first fastening member 242 comes into contact with the stopper member 210 attached to the second fastening member 244. At this time, an amount of relative displacement between the first fastening member 242 and the second fastening member 244 in the vertical direction is limited by the contact between the inner bracket 248 and the stopper member 210, so that durability can be improved by preventing excessive deformation of the elastic main body 246 made of rubber or the like.

[0161] Furthermore, the stopper member 210 is capable of effectively reducing the vibration due to the damping effect of the first elastic body 224 because the first elastic body 224 is formed of a material with high damping. Furthermore, the stress due to the load effect is concentrated on the stress concentration parts 28, 28 located at the corners of the recessed grooves 226, 226. Thus, the damping effect exhibited by the deformation of the first elastic body 224 can be more effectively obtained.

[0162] Furthermore, the portion of the stopper member 210 configured to directly contact the inner bracket 248 is formed of the second elastic body 232, which is softer than the first elastic body 224. Thus, during the initial contact between the inner bracket 248 and the stopper member 210, it is possible to advantageously obtain shock absorption properties and prevent shock, impact noise, and the like. Furthermore, when the inner bracket 248 is pressed more strongly, the elastic body 224, which is harder than the second elastic body 232, will limit the amount of relative displacement between the first fastening member 242 and the second fastening member 244, thereby effectively achieving the desired stopper function.

[0163] In addition, the spring constant of the metal spring 214 is comparatively small during the initial contact between the inner bracket 248 and the stopper member 210, so that the metal spring 214 is elastically deformed by a small force. Thus, shock absorption properties can also be advantageously obtained by the elasticity of the metal spring 214. Furthermore, since the spring constant of the metal spring 214 increases linearly as the amount of deformation increases, in the case where the impact is large, the amount of relative displacement between the first fastening member 242 and the second fastening member 244 is also effectively limited by the elasticity of the metal spring 214.

[0164] Furthermore, with respect to the metal spring 214 in its initial state where no load is applied, the first plate-shaped part 218 supporting the vibration-damping composite body 240 rises upward toward the radially inner side. The upper surface of the vibration-damping composite body 240 also rises in the same direction as the first plate-shaped part 218. Thus, when the lower surface of the inner support 248, which extends approximately perpendicular to the vertical direction, comes into contact with the vibration-damping composite body 240, the contact area gradually increases due to the metal spring 214.Therefore, while the shock absorption effect is effectively achieved by the small contact area in the initial stage of contact, it is possible to effectively limit the relative displacement between the first fixing member 242 and the second fixing member 244 when the deformation of the metal spring 214 becomes large due to the contact on the large area.

[0165] While the present invention has been described in detail above with reference to practical embodiments, the invention is not limited by the specific disclosures thereof. For example, the shape, arrangement, number of formations, and the like of the recessed portion and the gap can be appropriately changed depending on the required vibration damping properties and the like.

[0166] In the present practical embodiment, an example is shown in which, during the application of load, the first elastic body deforms such that the opening angle formed by the inner surfaces of the recessed part at the stress concentration part decreases. However, it would also be possible, for example, for the first elastic body to deform to increase the opening angle formed by the inner surfaces of the recessed part at the stress concentration part, thereby increasing the stress of the first elastic body at the stress concentration part.

[0167] Furthermore, in the first to fourth practical embodiments, a structure is illustrated in which the proximal end of the doorstop is formed by the first elastic body, while the distal end of the doorstop is formed by the second elastic body. However, it would also be possible, for example, to use a structure in which the distal end of the doorstop is formed by the first elastic body, while the proximal end of the doorstop is formed by the second elastic body.Furthermore, in the construction as in the fifth practical embodiment in which the first elastic body and the second elastic body are arranged coaxially, it would also be acceptable that the first elastic body has a round tubular shape constituting the outer peripheral portion and has the recessed part opening to the radially inner side, while the second elastic body has a cylindrical shape constituting the radially inner portion and has the convex part protruding to the radially outer side.

[0168] The doorstops according to the first to fifth practical embodiments have a generally circular shape when viewed in the axial direction. However, the same structure can be achieved even with, for example, an oval shape, a polygonal shape, an irregular shape, or the like when viewed in the axial direction. Similarly, the shape of the stopper rubber according to the sixth to eighth practical embodiments is not particularly limited when viewed in the direction of load action.

[0169] Furthermore, the attachment structure of the doorstop to the body frame according to the first to fifth practical embodiments is not particularly limited. For example, a convex attachment protruding in the axial direction may be provided to the first elastic body, while a concave or hole may be formed in the body frame. By inserting the convex attachment of the first elastic body into the concave or hole of the body frame, the first elastic body can be attached to the body frame in an adhesive-free manner.

[0170] In the ninth practical embodiment, the specific structure of the metal spring 184 is not particularly limited. For example, the metal spring 184 may be an unfolded disc spring or the like. Furthermore, the metal spring is not necessary to have the attachment structure to the body frame 24 or the like (namely, the attachment part 198 provided with the bolt hole 200 in the previous practical embodiment), but the attachment structure may be provided separately from the metal spring. Furthermore, a vibration-damping composite body equipped with a metal spring can also be formed by providing a metal spring in series in the direction of load action with respect to the vibration-damping composite body according to the first to fifth practical embodiments.

[0171] In addition, the vibration damping composite body according to the first to fifth practical embodiments is not necessarily used as a door stopper used only in a door portion of a vehicle, but can also be used, for example, in a stopper of a vibration damping device such as an engine mount, a stopper of a door of a building, and the like. EXPLANATION OF REFERENCE SYMBOLS

[0172] 10, 30, 50, 60, 70: Door stop (vibration-damping composite body), 12, 32, 52, 62, 72, 82, 132, 162, 186, 224: First elastic body, 14, 34, 54, 74, 84, 134, 164, 188, 232: Second elastic body, 16, 38, 86, 136, 166, 228: Projecting part, 18, 40, 56, 66, 76, 88, 138, 168: Recessed part, 22, 48, 58, 68, 79, 96, 142, 172, 236: Gap, 24: Body frame (Fastening target element), 28: Stress concentration part, 46, 78, 234: Convex part, 80, 120, 160: Stop rubber (vibration damping composite body), 180: Door stop (vibration damping composite body equipped with a metal spring), 182, 240: Vibration damping composite body, 184, 214: Metal spring, 192, 216: Bending part, 198: Attachment part, 210: Stop element (vibration damping composite body equipped with a metal spring), 222: Clinching piece (attachment part), 226: Recessed groove (recessed part), 244: Second fastening element (fastening target element)

Claims

[1] Vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) comprising a first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) and a second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232) which overlap each other, characterized by , that the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) is made of a material with a higher damping than that of the second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232), the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) has a recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) which opens onto a surface of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), and the recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) forms a gap (22, 48, 58, 68, 79, 96, 142, 172, 236), and a stress concentration part (28) configured to be subjected to increased stress during a load action is placed on a wall of the gap (22, 48, 58, 68, 79, 96, 142, 172, 236) of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), wherein the first elastic body (12, 32, 52, 62, 82, 132, 162, 186, 224) and the second elastic body (14, 34, 54, 84, 134, 164, 188, 232) overlap in a direction of load action, and wherein the first elastic body (12, 32, 82, 132, 162, 186, 224) has a protruding part (16, 38, 86, 136, 166, 228) which is provided on an overlapping surface with the second elastic body (14, 34, 84, 134, 164, 188, 232) and protrudes towards the second elastic body (14, 34, 84, 134, 164, 188, 232), and the recessed part (18, 40, 88, 138, 168, 226) is formed on an outer periphery of the protruding part (16, 38, 86, 136, 166, 228). [2] The vibration damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) according to claim 1, wherein the recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) has a groove shape. [3] The vibration damping composite body (10, 30, 50, 70, 80, 120, 160, 182) according to claim 1 or 2, wherein the recessed part (18, 40, 56, 76, 88, 138, 168) of the first elastic body (12, 32, 52, 72, 82, 132, 162, 186) is open to a lateral side with respect to a direction of load action. [4] Vibration damping composite body (10, 30, 80, 120, 160, 182, 240) according to one of claims 1 to 3, wherein a projecting distal end surface of the projecting part (16, 38, 86, 136, 166, 228) is in contact with the second elastic body (14, 34, 84, 134, 164, 188, 232), and the first elastic body (12, 32, 82, 132, 162, 186, 224) and the second elastic body (14, 34, 84, 134, 164, 188, 232) are in a projecting direction of the projecting part (16, 38, 86, 136, 166, 228) are in contact with each other at a position remote from the projecting part (16, 38, 86, 136, 166, 228) towards a radially outer side. [5] Vibration-damping composite body (30, 70, 182, 240) according to one of claims 1-4, wherein the recessed part (40, 76, 226) is open towards an overlapping surface of the first elastic body (32, 72, 186, 224) with the second elastic body (34, 74, 188, 232), the second elastic body (34, 74, 188, 232) has a convex part (46, 78, 234) inserted into the recessed part (40, 76, 226), the convex part (46, 78, 234) is partially in contact with an inner surface of the recessed part (40, 76, 226), and the gap (48, 79, 236) is formed between the convex part (46, 78, 234) and the inner surface of the recessed part (40, 76, 226). [6] Vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) according to one of claims 1-5, wherein the second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232) is formed from a material having a smaller compression set than that of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224). [7] Vibration-damping composite body (180, 210) equipped with a metal spring, comprising: the vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) according to any one of claims 1-6; and a metal spring (184, 214) provided in series with the vibration damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) in a direction of load action. [8] Vibration-damping composite body (180, 210) equipped with a metal spring according to claim 7, wherein the metal spring (184, 214) has an attachment part (198, 222) for a component (24) to be damped. [9] Vibration-damping composite body (180, 210) equipped with a metal spring, comprising: a vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) comprising a first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) and a second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232) which overlap one another, characterized by , that the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) is made of a material with a higher damping than that of the second elastic body (14, 34, 54, 74, 84, 134, 164, 188, 232), the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224) has a recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) which opens onto a surface of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), and the recessed part (18, 40, 56, 66, 76, 88, 138, 168, 226) forms a gap (22, 48, 58, 68, 79, 96, 142, 172, 236), and a stress concentration part (28) configured to be subjected to increased stress during a load action is set on a wall of the gap (22, 48, 58, 68, 79, 96, 142, 172, 236) of the first elastic body (12, 32, 52, 62, 72, 82, 132, 162, 186, 224), and a metal spring (184, 214) provided in series with the vibration-damping composite body (10, 30, 50, 60, 70, 80, 120, 160, 182, 240) in a direction of load action, wherein the metal spring (184, 214) comprises a disc spring folded at a bent part (192, 216).

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