Patent Publication Number: US-8978624-B2

Title: Vibration damping insulator for fuel injection valve

Description:
FIELD OF THE DISCLOSURE 
     The present invention relates to a vibration insulator for a fuel injection valve. The vibration insulator is configured to damp vibration that occurs in the fuel injection valve, which injects fuel into an internal combustion engine. 
     BACKGROUND OF THE DISCLOSURE 
     Conventionally, internal combustion engines of one type in which fuel is injected into the inside of a combustion chamber, that is, internal combustion engines of the in-cylinder injection type, for example, have the distal end portion of a fuel injection valve inserted into and supported by an insertion hole of a cylinder head and have the proximal end portion of the fuel injection valve inserted into and supported by a delivery pipe (a fuel injection valve cup), whereby the fuel injection valve is provided across the cylinder head and the delivery pipe. When a fuel pressure supplied to the fuel injection valve through the delivery pipe has changed due to injection or stopping of the fuel, vibration based on the change in fuel pressure and vibration accompanying the operation of the fuel injection valve usually occur to the above fuel injection valve. For this reason, it is often the case that a vibration insulator to absorb and damp such vibration of a fuel injection valve is attached between the fuel injection valve and an insertion hole of a cylinder head. 
     On the other hand, the cylinder head and the delivery pipe are originally parts of separate bodies. Therefore, changes in the relative positions thereof, which are caused by, for example, tolerances associated with production or processing of these parts, tolerances associated with assembly in the production, thermal deformation, and various vibrations that accompany the operation of the internal combustion engine, are unavoidable. That is, the axis of the fuel injection valve provided across the cylinder head and the delivery pipe becomes inclined relative to the axis of the insertion hole of the cylinder head, whereby positions at which the fuel injection valve is supported by the cylinder head and the delivery pipe deviate from correct positions. Further, such positional deviation causes problems such as partial slack of an O-ring at the proximal end of the fuel injection valve, the O-ring serving to prevent fuel leakage between the fuel injection valve and the delivery pipe (fuel injection valve cup). Therefore, the positional deviation may possibly cause fuel leakage. 
     For this reason, insulators designed to not only absorb and damp vibration of the fuel injection valve but also reduce the influence of such inclination of the axis of the fuel injection valve have been proposed, and an insulator described in Patent Document 1 is known as one example thereof. The insulator described in Patent Document 1, as shown in  FIG. 12 , includes an annular adjustment element  60  sandwiched between a shoulder section  54  of a cylinder head  51  and a tapered stepped section  57  of a fuel injection valve  55 , the diameter of which is enlarged in a tapered shape to face the shoulder section  54 . While an injection nozzle  56  of the fuel injection valve  55  is arranged by being inserted into the insertion hole  52  (a receiving hole) of the cylinder head  51 , the shoulder section  54  of the cylinder head  51  has an opening into a side wall  53  of the insertion hole  52 . The adjustment element  60  has a first leg  61  extending along the shoulder section  54  of the insertion hole  52 , and a second leg  62  extending along the tapered stepped section  57  of the fuel injection valve  55 . Additionally, a structure elastically supporting the fuel injection valve  55  with respect to the cylinder head  51  is obtained by having the first leg  61  in surface contact with the shoulder section  54  of the insertion hole  52 , and having the second leg  62  in surface contact with the tapered stepped section  57  of the fuel injection valve  55 . 
     According to the thus configured insulator, even when the axis C 2  of the fuel injection valve  55  has deviated from the centered position between the insertion hole  52  of the cylinder head  51  and a delivery pipe in assembly, the first leg  61  moves along the shoulder section  54  of the insertion hole  52  due to a force generated by the second leg  62 , which flexes in accordance with the tapered stepped section  57  of the fuel injection valve  55 . This serves to appropriately compensate the positional relations of the fuel injection valve  55  with the insertion hole  52  and the delivery pipe. 
     When the internal combustion engine is operated, a high pressing force based on the above described fuel pressure is applied to the second leg  62  of the adjustment element  60  through the tapered stepped section  57  of the fuel injection valve  55 . At this time, a force toward the shoulder section  54  of the insertion hole  52  and a force toward the outer circumference of the adjustment element  60  are applied to the second leg  62  of the adjustment element  60  from the tapered stepped section  57  of the fuel injection valve  55  in a manner corresponding to the tapering angle of the tapered stepped section  57 . 
     PRIOR ART DOCUMENT 
     Patent Document 
     
         
         Patent Document 1: Japanese Patent No. 4191734 
       
    
     SUMMARY OF THE INVENTION 
     Problems that the Invention is to Solve 
     Out of these forces, in  FIG. 12 , the force from the fuel injection valve  55  toward the outer circumference of the adjustment element  60  acts in a manner enlarging the ring diameter of the adjustment element  60 , and therefore, may possibly warp the second leg  62  toward the outer circumference thereof. Particularly, when the second leg  62  has been warped such that the opening of the second leg  62  is enlarged, a position at which the second leg  62  supports the tapered stepped section  57  of the fuel injection valve  55  shifts toward the inner circumference of the second leg  62  having a slope along the tapered stepped section  57 . That is, since the vertical position of the fuel injection valve  55  with respect to the cylinder head  51  shifts, and results in such consequences as change of the fuel injection position, whereby there is a risk that the most suitable combustion state cannot be maintained. 
     Accordingly, it is an objective of the present invention to provide a vibration insulator for a fuel injection valve, the a vibration insulator being capable of, even when an internal combustion engine is in operation, not only performing the function of damping vibration of the fuel injection valve but also suitably maintaining the fuel injection position of the fuel injection valve. 
     Means for Solving the Problems 
     In order to solve the above problem, the present invention provides a vibration insulator for a fuel injection valve that is configured to damp vibration that occurs to the fuel injection valve. The fuel injection valve is mounted on the cylinder head while being inserted into the insertion hole provided in the cylinder head. While the shoulder section is annularly formed in an inlet portion of the insertion hole to have an opening, the fuel injection valve includes a stepped section, the diameter of which is enlarged in a tapered manner to have a tapered surface facing the shoulder section. The vibration insulator is located between the stepped section and the shoulder section, and the vibration insulator includes a circular ring-like tolerance ring abutting the tapered surface. The above described vibration insulator for a fuel injection valve is characterized in that the tolerance ring has a sleeve section formed integrally therewith in a manner extending from a surface in a part, of the tolerance ring, that faces away from the tapered surface, the sleeve section having a circular ring-like shape that is concentric with the tolerance ring. 
     According to this configuration, the stiffness of the tolerance ring itself is increased by the sleeve section provided integrally thereto to extend therefrom, whereby the durability of the tolerance ring against a force that is received thereby from the tapered surface of the fuel injection valve and acts in a manner enlarging the opening of the tolerance ring is improved. Thus, warping of the tolerance ring is prevented from occurring, and a position at which the tapered surface of the fuel injection valve abuts the tolerance ring is maintained. That is, the fuel injection position of the fuel injection valve with respect to the combustion chamber is suitably maintained, and the combustion state is appropriately maintained as well. 
     The vibration insulator may include an elastic member arranged between the tolerance ring and the shoulder section. In order to damp vibration that occurs in the fuel injection valve, the elastic member is formed in a circular ring-like shape corresponding to the bottom surface of the tolerance ring. The sleeve section may extend from the bottom surface of the tolerance ring toward the shoulder section along the elastic member, and may be formed with the extending length of the sleeve section being shorter than the distance between the bottom surface of the tolerance ring and the above shoulder section. 
     This configuration brings the sleeve section into contact with the shoulder section when the elastic member has deformed by receiving a strong pressing force from the fuel injection valve. Therefore, excessive deformation of the elastic member, which might plastically deform when having deformed greatly, is restricted. That is, it is made possible to use the elastic member with an amount of deformation (height) thereof being limited within a range that permits the elastic member to elastically deform. As a result, the elasticity of the elastic member is suitably maintained, and the function of absorbing and damping vibration by means of the elasticity thereof is maintained. 
     A coil spring helically arranged in a manner corresponding to the circular ring-like shape of the elastic member may be embedded in the elastic member. The sleeve section, which extends from the bottom surface of the tolerance ring, may be formed with the extending length of the sleeve section being shorter than the diameter of the helix of the coil spring. 
     This configuration restricts excessive deformation of the elastic member, the elasticity of which is adjusted by the coil spring. In other words, this configuration allows the elastic member to be used within the extent (in height) that permits the elastic member to elastically deform. As a result, the elasticity of the elastic member is suitably maintained, and the function of absorbing and damping vibration by means of the elasticity thereof is maintained. 
     The sleeve section may be provided toward the outer circumference of the elastic member. 
     This configuration causes the elastic member, which tends to deform in a manner radially enlarging when being pressed, to press the sleeve section toward the outer circumference. On the other hand, when the tapered surface of the fuel injection valve presses the tolerance ring while abutting the tolerance ring, the tolerance ring receives a force that acts in a direction that enlarges the opening of the tolerance ring. That is, the tolerance ring receives outward-acting forces in both of the surface thereof facing the tapered surface of the fuel injection valve and the sleeve section, respectively. On this basis, as compared to a case, for example, where the tolerance ring receives an outward-acting force only in the surface thereof facing the tapered surface of the fuel injection valve, warping of the tolerance ring is prevented from occurring. This makes it possible to maintain the position at which the tapered surface of the fuel injection valve abuts the tolerance ring. As a result, the fuel injection position of the fuel injection valve with respect to the combustion chamber is suitably maintained, whereby the most suitable combustion state is maintained. 
     A surface of the sleeve section that faces the elastic member may be formed into a shape that follows the external form of the helix of the coil spring. 
     According to this configuration, a force from the elastic member, when the elastic member is pressed to deform toward the outer circumference, is more likely to be transmitted to the sleeve section without being dispersed. Therefore, the elastic member, when going to deform, presses the sleeve section with a stronger force toward the outer circumference. As a result, warping of the tolerance ring, which might be caused by a force received by the tolerance ring from the tapered surface of the fuel injection valve, is suppressed to a greater degree. In other words, it is made possible to maintain the position at which the tapered surface of the fuel injection valve abuts the tolerance ring. 
     The sleeve section may be provided toward each of the inner circumference and the outer circumference of the elastic member. 
     According to this configuration, reactive forces that a pressing force from the fuel injection valve causes on the elastic member inserted between an inner circumferential sleeve section and an outer circumferential sleeve section of the tolerance ring act toward the tolerance ring. As a result, even when the tolerance ring is pressed by the fuel injection valve, the position of the tolerance ring with respect to the shoulder section is maintained. On this basis, the fuel injection position of the fuel injection valve with respect to the combustion chamber is suitably supported maintained by the tolerance ring. The most suitable combustion state is maintained as well. 
     The distance between the inner circumferential sleeve section and the outer circumferential sleeve section may be set to become wider toward the shoulder section from the bottom surface of the tolerance ring. 
     According this configuration, reactive forces caused on the elastic member by a pressing force from the fuel injection valve, which act toward the inner circumference and the outer circumference, are converted into reactive forces resisting the pressing force from the fuel injection valve in accordance with the slope angles of the inner circumferential sleeve section and the outer circumferential sleeve section. These forces act to maintain the position of the tolerance ring with respect to the shoulder section. This also serves to suitably maintain, with respect to the combustion chamber, the fuel injection position of the fuel injection valve supported by the tolerance ring. The most suitable combustion state is maintained as well. 
     The sleeve section may be provided toward the inner circumference of the elastic member. 
     According to this configuration, the stiffness of the tolerance ring is improved also by the sleeve section, which extends from the inner circumference. Therefore, improvement in durability of the tolerance ring against a force that is received by the tolerance ring from the tapered surface of the fuel injection valve and acts to enlarge the opening of the tolerance ring is enabled. 
     The vibration insulator may include an elastic member arranged between the tolerance ring and the shoulder section. The elastic member is formed in a circular ring-like shape corresponding to the bottom surface of the tolerance ring in order to damp vibration that occurs to the fuel injection valve. The sleeve section is extended out to a position facing the surface, of the cylinder head, that has the insertion hole opened therein. The elastic member may be used to provide a predetermined distance between the sleeve section and the surface of the cylinder head. 
     This configuration also improves the stiffness of the tolerance ring by means of the sleeve section. Thus, improvement in durability of the tolerance ring against a force that is received by the tolerance ring from the tapered surface of the fuel injection valve and acts to enlarge the opening of the tolerance ring is enabled. Furthermore, when the elastic member is deformed into a crushed form, the sleeve section of the tolerance ring abuts the cylinder head. Therefore, excessive deformation of the elastic member is restricted, and it is made possible to use the elastic member within the extent (in height) that permits the elastic deformation thereof. This makes it possible be suitably maintained the elasticity of the elastic member and to maintain the function of absorbing and damping vibration by means of the elasticity. 
     The vibration insulator may further include a metal plate having a circular ring-like portion located between the elastic member and the shoulder section. The metal plate may be formed into a state pinching the tolerance ring and the elastic member together from the inner circumference of the tolerance ring. 
     According this configuration, the relative position of the tolerance ring, which is not easy to be strongly joined to the elastic member, with respect to the elastic member is defined by the plate from the inner circumference. This makes it possible to facilitate appropriate stacking of the tolerance ring onto the elastic member. As a result, improvement in feasibility of this vibration insulator is enabled. 
     The outer circumferential edge of the metal plate may be molded into a shape having a burr generated thereon, the burr having been cut upward toward the elastic member. 
     According to this configuration, the size of the shoulder section formed on the insertion hole of the cylinder head is formed into the requisite minimum size that enables deviation of the axis of the fuel injection valve from the centered position to be compensated by movement of the vibration insulator. 
     The tolerance ring may be formed of a metal having the same level of hardness as the housing of the fuel injection valve. 
     According to this configuration, the pressing force that acts on the fuel injection valve is distributed equally between the tapered surface of the fuel injection valve and the surface of a part, of the tolerance ring, that faces the tapered surface of the fuel injection valve. Therefore, compensating movement that is performed by the tolerance ring in response to the deviation of the axis of the fuel injection valve from the centered position is suitably performed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a diagram schematically showing the outline of a fuel injection system to which a first embodiment of a vibration insulator according to the present invention is applied; 
         FIG. 2  is a plan view showing a planer structure of the vibration insulator of  FIG. 1 ; 
         FIG. 3  is a cross-sectional view showing a cross-sectional structure of the vibration insulator of  FIG. 2 ; 
         FIG. 4  is an enlarged end view showing the structure of an end face of the vibration insulator of  FIG. 3 ; 
         FIGS. 5(   a ) and  5 ( b ) are diagrams illustrating a compensating function that responds to deviation of the vibration insulator of  FIG. 1  from the centered position, where  FIG. 5(   a ) shows a centered state, and  FIG. 5(   b ) shows an off-center state; 
         FIG. 6  is an end view showing the structure of an end face of the vibration insulator according to a second embodiment of the present invention; 
         FIG. 7  is an end view showing the structure of an end face of the vibration insulator according to a third embodiment of the present invention; 
         FIG. 8  is an end view showing the structure of an end face of the vibration insulator according to a fourth embodiment of the present invention; 
         FIG. 9  is an end view showing the structure of an end face of the vibration insulator according to a fifth embodiment of the present invention; 
         FIG. 10  is an end view showing the structure of an end face of the vibration insulator according to a modification of the first embodiment; 
         FIG. 11  is an end view showing the structure of an end face of the vibration insulator according to a modification of the third embodiment; and 
         FIG. 12  is a cross-sectional view showing a cross-sectional structure of a conventional vibration insulator. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       FIGS. 1 to 5  illustrate a vibration insulator according to a first embodiment of the present invention. 
       FIG. 1  is a diagram schematically showing a schematic structure of a fuel injection system to which a vibration insulator of this embodiment is applied.  FIG. 2  is a diagram showing the structure of the vibration insulator in a flat plane.  FIG. 3  is a diagram showing the structure of the vibration insulator in a cross-sectional view.  FIG. 4  is a diagram showing the structure of an end face of the vibration insulator in an end view.  FIGS. 5(   a ) and  5 ( b ) are illustrations for illustrating states of compensating movement performed in response to deviation from the center position of the vibration insulator, where  FIG. 5(   a ) is a diagram showing a state where the axis C thereof is centered, and  FIG. 5(   b ) is a diagram showing a state where the axis C thereof is off-center. 
     As shown in  FIG. 1 , a fuel injection system  10  is provided with a fuel injection valve  11 . While a part of the fuel injection valve  11  in the distal end (lower in  FIG. 1 ) thereof is supported by being inserted into an insertion hole  15  of the cylinder head  12 , another part of the fuel injection valve  11  in the proximal end (upper in  FIG. 1 ) thereof is supported by a fuel injection valve cup  14  included in a delivery pipe  13 . The fuel injection valve  11  is thus built between the cylinder head  12  and the delivery pipe  13 . 
     The insertion hole  15  of the cylinder head  12  is formed, as a hole stepped with multiple steps, to extend through the cylinder head  12  from an outer surface  12 A thereof to an inner surface  12 B thereof, the hole having a hole diameter that narrows sequentially in a direction from the outer surface  12 A of the cylinder head  12  (the upper part of  FIG. 1 ) toward the inner surface  12 B thereof (the lower part of  FIG. 1 ) facing a combustion chamber of an internal combustion engine of the in-cylinder injection system. That is, the hole diameter at an inlet section  17  of the insertion hole  15 , which is an entrance that opens through the outer surface  12 A of the cylinder head  12 , is the largest, and the hole diameter at a distal end hole section  16  of the insertion hole  15 , which opens through the inner surface  12 B, is the smallest. As a result, a stepped section based on a difference in the hole diameter is formed on each part of the insertion hole  15  at which the hole diameter changes, whereby, for example, a shoulder section  18  as one of the stepped sections is formed between the inlet section  17  and an intermediate hole section  19  which continues from the inlet section  17 . In other words, the shoulder section  18  is formed such that the opening of an edge section of the intermediate hole section  19  in one side thereof facing the outer surface  12 A is annularly enlarged. Since the distal end hole section  16  of the insertion hole  15  is communicated with the combustion chamber of the in-cylinder injection system, an injection nozzle  23  of the fuel injection valve  11  is inserted into and thereby mounted on the distal end hole section  16  of the insertion hole  15 . As a result, the distal end hole section  16  is configured to introduce, into the combustion chamber, high pressure fuel injected from the injection nozzle  23 . 
     Since the delivery pipe  13  is designed to supply to the fuel injection valve  11  high pressure fuel, the pressure of which has been accumulated to an injection pressure, the delivery pipe  13  includes the fuel injection valve cup  14  that the proximal end section of the fuel injection valve  11  is inserted into and thereby mounted on. When the proximal end section of the fuel injection valve  11  is inserted into the fuel injection valve cup  14 , the fuel sealing performance between the proximal end section of the fuel injection valve  11  and the inner circumferential surface  14 A of the fuel injection valve cup  14  is ensured by an O-ring  29  arranged therebetween. 
     The fuel injection valve  11  is designed to inject high pressure fuel, which is supplied from the delivery pipe  13 , into the combustion chamber defined by the cylinder head  12  with predetermined timing. A housing of the fuel injection valve  11  has a cylindrical shape, stepped with multiple steps, which sequentially narrows in directions from the center in the axial direction toward the distal end (the insertion hole  15 ) and toward the proximal end (the fuel injection valve cup  14 ). 
     That is, the housing of the fuel injection valve  11  includes a large diameter section  20  at the center thereof, and includes in order from the large diameter section  20  toward the proximal end: a proximal relay section  26  having a smaller diameter than the large diameter section  20 ; a proximal insertion section  27  having a smaller diameter than the proximal relay section  26 ; and a proximal sealing section  28  having a smaller diameter than the proximal insertion section  27 . The proximal relay section  26  is provided with a connector  26 J to which wiring for transmission of a drive signal to, for example, an electromagnetic valve built inside the fuel injection valve  11  for the purpose of controlling fuel injection. The proximal sealing section  28  is inserted into and thereby supports the O-ring  29 . 
     The O-ring  29  is formed of an elastic member made of rubber or the like that is fuel-resistant, substantially in a circular ring-like shape and has pressure resistance against the pressure of high pressure fuel. The inner circumference of the O-ring  29  is configured to contact tightly to the outer circumferential surface of the proximal sealing section  28 , and therefore delivers, through tight contact between the inner circumference of the O-ring  29  and the outer circumferential surface of the proximal sealing section  28 , sealing performance that prevents fuel leakage of high pressure fuel between the fuel injection valve  11  and the O-ring  29 . Furthermore, the outer circumference of the O-ring  29  is formed into a size that allows the O-ring  29  to tightly contact the inner circumferential surface  14 A of the fuel injection valve cup  14  of the delivery pipe  13 . As a result, when the proximal end of the fuel injection valve  11  is inserted into the fuel injection valve cup  14  of the delivery pipe  13 , the outer circumference of the O-ring  29  of the fuel injection valve  11  tightly contacts the inner circumferential surface  14 A of the fuel injection valve cup  14 , and thereby displays a sealing performance against the high pressure fuel. When the O-ring  29  displays the sealing performance toward both of the outer circumferential surface of the proximal sealing section  28  and the inner circumferential surface  14 A of the fuel injection valve cup  14 , the fuel sealing performance against the high pressure fuel is ensured between the fuel injection valve  11  and the fuel injection valve cup  14 . 
     Furthermore, the housing of the fuel injection valve  11  includes in order from the large diameter section  20  toward the distal end: a medium diameter section  21  having a narrower diameter than the large diameter section  20 ; and a small diameter section  22  having a narrower diameter than the medium diameter section  21 . The injection nozzle  23 , which injects fuel, is provided at the distal end of the small diameter section  22 . A sealing section  25  used for ensuring a sealing performance thereof with the wall surface of the insertion hole  15  to maintain airtightness of the combustion chamber is provided in a part of the small diameter section  22  located nearer to the proximal end than injection nozzle  23  is located. 
     Between the large diameter section  20  and the medium diameter section  21 , a stepped section based on the difference between the outer diameter of the large diameter section  20  and the outer diameter of the medium diameter section  21  is formed, and this stepped section is provided with a tapered surface  24  having a shape narrowed in a direction toward the distal end. That is, when the fuel injection valve  11  is inserted into the insertion hole  15 , the tapered surface  24  of the fuel injection valve  11  faces the shoulder section  18  located at the inlet section  17  of the insertion hole  15  of the cylinder head  12  with a predetermined slope. The angle α (refer to  FIG. 4 ) of the tapered surface  24  with respect to the central axis (axis C) of the fuel injection valve  11  is shown as an angle with respect to an axis parallel C 1 , which is parallel to the axis C. Specifically, although it is preferable for the angle α of this tapered surface  24  to be 30 to 60 degrees, the angle α is selectable from values larger than 0 degrees and smaller than 90 degrees. 
     An annular vibration insulator  30  is provided between the tapered surface  24  of the fuel injection valve  11  and the shoulder section  18  of the insertion hole  15 . The vibration insulator  30  is designed for absorbing and damping, when a change in the fuel pressure of fuel supplied through the delivery pipe  13  has occurred with the fuel having been injected or stopped by the fuel injection valve  11 , vibration that occurs to the fuel injection valve  11  based on the fuel pressure change. 
     The outer diameter Ra (refer to  FIGS. 2 and 3 ) of the vibration insulator  30  is formed with a size that enables the vibration insulator  30  to be placed on the annular shoulder section  18 . Furthermore, the inner diameter Rb (refer to  FIGS. 2 and 3 ) of the vibration insulator  30  is formed with a size that permits the medium diameter section  21  of the fuel injection valve  11  to be inserted through the vibration insulator  30  with play existing between the medium diameter section  21  and the vibration insulator  30 . As shown in  FIGS. 1 and 4 , a ring  21 R having an outer diameter that is larger than the inner diameter Rb of the vibration insulator  30  is provided in a part of the medium diameter section  21  in the distal end of the fuel injection valve  11 . As shown in  FIG. 1 , the vibration insulator  30 , under the condition where the medium diameter section  21  is inserted therethrough, is prevented by the ring  21 R from coming off from the medium diameter section  21  of the fuel injection valve  11 . 
     As shown in  FIG. 3 , the vibration insulator  30  includes: an annular vibration damping member  31 ; an annular plate  32  formed with a cross section having a channel-like shape substantially surrounding the lower part (the lower side in  FIG. 3 ) and the inner circumferential section (a part facing the axis C in  FIG. 3 ) of the vibration damping member  31 ; and an annular tolerance ring  33  provided in the upper part of vibration damping member  31  (the upper part in  FIG. 2 ). That is, the plate  32  has a plate bottom section  37 , on which the vibration damping member  31  is stacked, and the tolerance ring  33  is further stacked on the vibration damping member  31 . 
     In order to function as a member that absorbs and damps vibration of the fuel injection valve  11 , the vibration damping member  31  includes as shown in  FIG. 4 : an elastic member  36  made of rubber or the like; and an annular coil spring  34  embedded in the elastic member  36  under the condition where the annular coil spring  34  forms the same annular shape as the elastic members  36 . That is, the coil spring  34  is formed in a shape obtained by curving a helical long body into a loop such that the helical long body surrounds the fuel injection valve  11 .  FIG. 4  shows a portion corresponding to one turn of the helix of the coil spring  34 , and the helix of the coil spring  34  is formed by having multiple turns as above continually connected to one another. A height H 11 , which is the helix diameter (outer diameter of one turn) of the helix of this coil spring  34  is also shown in  FIG. 4 . The coil spring  34  is produced using, as a material, spring steel as exemplified by stainless steel and piano wire.  FIGS. 5(   a ) and  5 ( b ) omit illustration of the coil spring  34  in order to reduce the complexity of the drawings. 
     The elastic member  36  is produced using, as a material, rubber or elastomer such as TPE, the rubber having been obtained by using fluorine rubber, nitrile rubber, hydrogenation nitrile rubber, fluorosilicone rubber, or acrylic rubber as a main ingredient and blending into the main ingredient a filler, such as carbon black, silica, clay, or calcium carbonate celite, and an antioxidant, a processing aid, and a vulcanizing agent that are suitable for each kind of rubber. 
     Thus, characteristics suitable for absorption and damping of vibration that occurs to the fuel injection valve  11  are imparted to the vibration damping member  31  based on vibration absorbing and vibration damping characteristics shown by the elastic member  36  and vibration absorbing and vibration damping characteristics shown by the coil spring  34 . Although the elastic member  36  and the coil spring  34  show appropriate vibration absorbing and vibration damping characteristics as long as a load within a predetermined range that permits the maintenance of the elasticity thereof is applied thereto, application of a load exceeding the predetermined range results in plastic deformation thereof and the loss of the elasticity, and thereby prevents the vibration absorbing and vibration damping characteristics from appropriately working. That is, when the elastic member  36  and the coil spring  34  experience deformation to forms vertically crushed by a pressing force from the fuel injection valve  11 , the elastic member  36  and the coil spring  34  deform freely as long as an amount of deformation thereof is a predetermined amount of deformation or smaller. However, the elastic member  36  and the coil spring  34  experience plastic deformation when having deformed to a level that exceeds the predetermined amount of deformation. In this embodiment, for example, as long as the height of the vibration damping member  31  after the deformation is within a range from the height H 11  thereof in a case when a pressing force is not applied thereto to a predetermined height H 12  in a case when a predetermined high pressing force is received thereby, appropriate elastic deformation of the vibration damping member  31  is maintained. In other words, a difference between the height H 11  and the height H 12  is the predetermined amount of deformation, which indicates the border of the elastic deformation and the plastic deformation of the vibration damping member  31 . On the other hand, when a pressing force exceeding the predetermined pressing force causes the vibration damping member  31  to deform such that the height of the vibration damping member  31  is made lower than the height H 12 , the vibration damping member  31  plastically deforms without appropriate elastic deformation thereof being maintained. 
     The plate  32  is formed of a metal such as stainless steel, for example, SUS 430, which is a stainless steel material to which a drawing process is easily applicable. As shown in  FIG. 4 , the plate  32  is formed with a cross section having a channel-like shape, and includes: a plate bottom section  37 ; a plate inner wall section  38  extending upward from the inner circumference of the plate bottom section  37  and along the vibration damping member  31 ; a plate cover section  39  folded toward the outer circumference from the upper end of the plate inner wall section  38  and covering a part of an inner circumferential section of the tolerance ring  33 . 
     The vibration damping member  31  is pressed against the upper surface of the plate bottom section  37 , and the lower surface of the plate bottom section  37  is caused to abut the shoulder section  18  of the insertion hole  15 . As a result, not only suitable sideward sliding ability of the plate  32  with respect to the shoulder section  18  of the insertion hole  15  is maintained, but also the force received by the plate  32  from the vibration damping member  31  is distributed evenly across the annular shoulder section  18 . Since the shoulder section  18  is a part of the cylinder head  12  formed of aluminum or the like, the hardness of the shoulder section  18  is lower than that of the coil spring  34 . Therefore, it is expected that, when the coil spring  34  comes in direct contact with the shoulder section  18 , an inconvenience of having a part of the shoulder section  18 , on which a force is concentrated, shaved or deformed may occur. However, in this embodiment, a force received by the plate  32  from the coil spring  34  passes through the annular plate bottom section  37  which corresponds to the annular shoulder section  18 , and is transmitted to the shoulder section  18  while being circumferentially dispersed. Therefore, the plate  32  prevents occurrence of the inconvenience that might occur when the coil spring  34  comes in direct contact with the shoulder section  18 . 
     As shown in  FIG. 4 , a burr section  37 R obtained by being pressed is formed at the end section of the plate bottom section  37  in the outer circumference thereof. That is, the burr section  37 R is cut diagonally upward from the bottom face of the plate bottom section  37  toward the outer circumference. The vibration insulator  30  is configured to be movable to the outer circumferential surface of the inlet section  17  as shown in  FIG. 5(   b ) by sliding on the shoulder section  18  from a position, as shown in  FIG. 5(   a ), that is located apart from the outer circumferential surface of the inlet section  17  and in the vicinity of the center of the step of shoulder section  18 . In this case, the provision of the burr section  37 R makes it possible to prevent the plate bottom section  37  of the vibration insulator  30  from being caught by or overriding a portion that remains unshaved as a bulge at the outer circumferential end of the shoulder section  18 . That is, the burr section  37 R is formed in a shape that does not come in contact with any portion that remains unshaved as a bulge at the outer circumferential end of the shoulder section  18 . A bulge at the outer circumferential end of the shoulder section  18  that the burr section  37 R is prevented from coming in contact with any portions may be formed intentionally. 
     The burr section  37 R as described above also prevents the outer circumferential end of the plate bottom section  37  from interfering with any bulge portion at the outer circumferential end of the shoulder section  18 , even when the vibration insulator  30  has moved until the vibration insulator  30  abuts the outer circumference of the shoulder section  18 . In other words, the burr section  37 R prevents decrease in movability of the plate  32 , which might be caused, for example, when the plate bottom section  37  is caught by a bulge portion at the outer circumferential end of the shoulder section  18 . Besides, the burr section  37 R prevents, for example, an incidence where a position (a position that is the height Hi upward apart from the shoulder section  18  in  FIG. 4 ) at which the tolerance ring  33  abuts the tapered surface  24  of the fuel injection valve  11  considerably changes with the plate bottom section  37 , which has overridden a bulge portion and become inclined. 
     As shown in  FIG. 4 , the plate inner wall section  38  is formed to rise along the vibration damping member  31  from the inner circumferential end of the plate bottom section  37 , thereby being extended upward along the medium diameter section  21  of the fuel injection valve  11 . 
     The plate cover section  39  extends such that the distal end section of the plate inner wall section  38  covers a part of an inner circumferential sloping surface  42  of the tolerance ring  33  stacked on the vibration damping member  31 . Further, the plate cover section  39  is abutted by the inner circumferential sloping surface  42  of the tolerance ring  33 , and imparts to the inner circumferential sloping surface  42  a force acting toward the outer circumference and downward. As a result, the plate cover section  39  functions not only to reinforce connection between the tolerance ring  33  and the vibration damping member  31 , but also to prevent the relative position between tolerance ring  33  and vibration damping member  31  from changing. 
     The tolerance ring  33  supports the fuel injection valve  11  with respect to the cylinder head  12  by abutting the tapered surface  24  of the fuel injection valve  11 . The tolerance ring  33  is formed of metal such as stainless steel, for example, SUS 304, which is a hard stainless steel material. Although metal having the same hardness as the tapered surface  24  of the fuel injection valve  11  is adopted as metal used as a material for the tolerance ring  33 , metal having the same hardness as a member, the coil spring  34  for example, having another level of hardness may be adopted. 
     As shown in  FIG. 4 , in the cross section of the tolerance ring  33 , a portion over the vibration damping member  31  (a part facing the proximal end of the fuel injection valve  11 ) is shaped in a right-angled triangle. In other words, the tolerance ring  33  includes: a ring bottom surface  40  connected to the vibration damping member  31 ; a ring outer circumferential surface  41 ; and the inner circumferential sloping surface  42  extending from the upper part of the ring outer circumferential surface  41  to the inner circumferential end of the ring bottom surface  40 . That is, as shown in  FIG. 3 , the inner circumferential sloping surface  42  in the cross section of the tolerance ring  33  forms a shape that tapers toward the center (the axis C) of the tolerance ring  33 . 
     The ring bottom surface  40  is abutted by the upper surface of the vibration damping member  31 , as shown in  FIG. 4 . The ring bottom surface  40  functions to transmit a pressing force to the upper surface of vibration damping member  31  as circumferentially dispersing through the entirety of the annular ring bottom surface  40 , the pressing force having been received by the tolerance ring  33  from the fuel injection valve  11 , whereby the pressing force is evenly applied to the vibration damping member  31 . As a result, inconveniences are prevented from occurring which include an incident where a locally concentrated force causes the vibration damping member  31  to plastically deform. 
     The diameter of the ring outer circumferential surface  41  is formed to have a diameter substantially equal to the outer diameter Ra of the plate bottom section  37  of the plate  32 . In other words, the diameter of the ring outer circumferential surface  41  is made substantially equal to the outer diameter Ra of the vibration insulator  30 , and therefore is set not to narrow a range, in the inlet section  17  of the insertion hole  15 , across which the vibration insulator  30  moves in the radial direction thereof. 
     As shown in  FIG. 4 , the inner circumferential sloping surface  42  is configured to have three slopes. In other words, the inner circumferential sloping surface  42  has: a joint section  43  provided as a joint sloping surface extending diagonally toward the outer circumference from the ring bottom surface  40  of the tolerance ring  33 ; an inner tapered surface  45 , which is one step higher than the joint section  43  and extends diagonally further toward the outer circumference; and an outer tapered surface  46 , which extends, from the inner tapered surface  45 , diagonally further toward the outer circumference at a moderate angle. The inner tapered surface  45  and the outer tapered surface  46  constitute an abutting section  44 , which faces the tapered surface  24  of the fuel injection valve  11 . In other words, the joint section  43  is located in the inner circumference with respect to the abutting section  44 , and most of the joint section  43  does not face the tapered surface  24  of the fuel injection valve  11 . 
     Specifically, the inner circumferential edge of the joint section  43  continues into the inner circumferential edge of the ring bottom surface  40  via the inner circumferential surface of the tolerance ring  33 . The plate cover section  39  of the plate  32  is bent toward the outer circumference to abut the joint section  43 . In other words, a force that acts toward the outer circumference and downward (toward the vibration damping member  31 ) is imparted by the plate cover section  39  to the joint section  43 . Therefore, pressure contact of the tolerance ring  33  to the vibration damping member  31  is reinforced, and the relative positional relationship thereof with the vibration damping member  31  is maintained unchanged. 
     A ridgeline  47  serving as a boundary between the inner tapered surface  45  and the outer tapered surface  46  is shown in  FIG. 4  as a corner (an apex) of a protrusion sticking out toward the inner circumference from the abutting section  44 . That is, while the ridgeline  47  is a part at which the outer circumferential edge of the inner tapered surface  45  abuts the inner circumferential edge of the outer tapered surface  46 , the inner tapered surface  45  and the outer tapered surface  46  constitute surfaces in a part of the tolerance ring  33  with two surfaces, the part facing the tapered surface  24  of the fuel injection valve  11 . In  FIG. 4 , the angle β 1  of the inner tapered surface  45 , the angle β 2  of the outer tapered surface  46  and the angle α of the tapered surface  24  of the fuel injection valve  11  are indicated as the respective angles of inclination to the axis parallel C 1  of the tolerance ring  33 . Furthermore, while the angle β 1  of the inner tapered surface  45  is set smaller than the angle α of the tapered surface  24  of the fuel injection valve  11 , the angle β 1  of the outer tapered surface  46  is set larger than the angle α of the tapered surface  24  of the fuel injection valve  11  (β 1 &lt;α&lt;β 2 ). That is, the angle (tapering angle) β 1  of the inner tapered surface  45  and the angle (tapering angle) β 2  of the outer tapered surface  46  are set to angles different from the angle (tapering angle) α of the tapered surface  24  of the fuel injection valve  11 , respectively. As a result, the relationship of the angle β 1  of inner tapered surface  45  and the angle β 2  of the outer tapered surface  46  with the angle α of the tapered surface  24  of the fuel injection valve  11  is such that the angle α is set to a size between the angle β 1  and the angle β 2 . The ridgeline  47 , shown in  FIG. 2 , which is located between the inner tapered surface  45  and the outer tapered surface  46  and has a circular shape, appears in  FIG. 4  as an apex that makes point contact with the tapered surface  24  of the fuel injection valve  11 . In other words, the ridgeline  47  makes line contact with the tapered surface  24  of the fuel injection valve  11 . Accordingly, the inner circumferential surface of the tolerance ring  33 , the ring bottom surface  40  and the ring outer circumferential surface  41  constitute surfaces in a part of the tolerance ring  33 , the part facing away from the tapered surface  24  of the fuel injection valve  11 . 
       FIG. 5(   b ) shows the axis Ca of the fuel injection valve  11  when the axis Ca is off-center with respect to the cylinder head  12 . Even when the fuel injection valve  11  inclines as shown in  FIG. 5(   b ) as compared to  FIG. 5(   a ), a change in the height Hi from the shoulder section  18  of insertion hole  15  to the ridgeline  47  is unlikely to occur because the vibration insulator  30  laterally (the radial direction) slides on the shoulder section  18 . As a result, a supported height of the fuel injection valve  11  with respect to the shoulder section  18  is maintained at the predefined height Hi. Furthermore, the vibration insulator  30  is capable of moving laterally in a manner following the deviation of the axis C of the fuel injection valve  11  from the centered position, whereby, even with the axis C of the fuel injection valve  11  being off-center, as in the case of the axis Ca, the length of a line segment extended from the ridgeline  47  to the axis Ca in the radial direction is kept equal to the length Ri of a line segment extended from the ridgeline  47  to the axis C in the radial direction when the axis C is centered as in the case of  FIG. 5(   a ). In other words, the distance from the centerline of the fuel injection valve  11  to the ridgeline  47  is maintained at a predetermined distance, that is, the length Ri. 
     Furthermore, when the axis C is deviated from the centered position under the influence of thermal expansion or the like, the vibration insulator  30  receives a laterally acting force from the fuel injection valve  11  due to a change in fuel pressure. The vibration insulator  30  is configured to absorb and damp vibration of the fuel injection valve  11  to a certain degree, but not to have the shape thereof flexed to a large degree, at the moment when the vibration insulator  30  receives the laterally acting force. In other words, the laterally acting force is hardly absorbed by the vibration insulator  30  and is efficiently used as a force that laterally moves the vibration insulator  30  on the shoulder section  18 . That is, when the axis C is deviated from the centered position, the vibration insulator  30  quickly reacts to a laterally acting force received thereby from the fuel injection valve  11 , and makes a movement in the inlet section  17  with a high level of responsiveness. 
     As shown in  FIG. 4 , when a force F is applied to the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11 , a force (a component of force of the load in the axial direction, that is, a load in the axial direction) Fa acting in a direction along the axis parallel C 1 , and a force (a component of force of the load in the radial direction, that is, a load in the radial direction) Fb acting in a direction orthogonal to the axis parallel C 1  are applied to the ridgeline  47  of the tolerance ring  33  in accordance with the angle α of the tapered surface  24 . The force Fa acting in the direction along the axis parallel C 1  is transmitted to the shoulder section  18  via the vibration damping member  31  and the plate  32 . On the other hand, the force Fb acting in the direction orthogonal to the axis parallel C 1  acts as a force that presses the upper part of the tolerance ring  33  toward the outer circumference thereof. At this moment, for such reasons as no abutment of the ring outer circumferential surface  41  to a side surface or the like of the inlet section  17 , the tolerance ring  33  might be unable to withstand this force Fb and be warped in a manner that a portion corresponding to the ridgeline  47  is opened outward together with the ring outer circumferential surface  41 . When the position of the ridgeline  47  moves outward by warping of the tolerance ring  33 , a part that is in the tapered surface  24  of the fuel injection valve  11  and abutting the ridgeline  47  moves toward the proximal section of the fuel injection valve  11 , that is, toward the upper part of the tapered surface  24 . In other words, the fuel injection valve  11  enters more deeply into the insertion hole  15  of the cylinder head  12 . In other words, the fuel injection valve  11  moves further toward the distal end (downward) with respect to the cylinder head  12 , and the supported height of the fuel injection valve  11  by the cylinder head  12  is lowered without being maintained at the height Hi. 
     For this reason, in this embodiment, the tolerance ring  33  has a sleeve section  35 , which extends from the ring bottom surface  40  toward the plate  32  and has a circular ring-like shape. The sleeve section  35  extends in the axial direction from a part of the ring bottom surface  40  along the outer circumference of the vibration damping member  31 , the part being toward the ring outer circumferential surface  41 . The sleeve section  35  is formed integrally with the tolerance ring  33 , and therefore, is formed of metal such as stainless steel, for example, SUS 304, which is a hard stainless steel material, as in the case of the tolerance ring  33 . 
     The size of the sleeve section  35  that extends from the ring bottom surface  40  toward the plate  32 , that is, the size thereof in the axial direction is formed substantially into the height H 12 . This height H 12  is lower than the height H 11  of the vibration damping member  31  when a high pressing force is not received thereby (H 12 &lt;H 11 ). For this reason, a gap (gap≦H 11 −H 12 ) exists between the distal end section of the sleeve section  35  and the plate bottom section  37  when the tolerance ring  33  does not receive a high pressing force from the fuel injection valve  11 . Since the burr section  37 R of the plate  32  has the outer circumference thereof warped upward, a portion of the distal end of the sleeve section  35  that faces the burr section  37 R is curved into a shape that follows the shape of the burr section  37 R, so that a gap between this portion and the burr section  37 R may be maintained at the length of H 11 −H 12 . For this reason, the size of the outer circumference of the sleeve section  35  in the axial direction is formed shorter than the height H 12 . 
     As a result, when the height of the vibration damping member  31  becomes the height H 12  in the case that the tolerance ring  33  presses and deforms the vibration damping member  31  through the ring bottom surface  40  upon receiving a high pressing force from the fuel injection valve  11 , the sleeve section  35  of the tolerance ring  33  abut the plate  32 . Therefore, the distance between the ring bottom surface  40  and the plate  32  is maintained at least at the height H 12 . That is, the vibration damping member  31  located between the ring bottom surface  40  and the plate  32  is not deformed into a height that is lower than the height H 12 . The height H 12  is a height that guarantees that the amount of the deformation does not exceed a predetermined amount of deformation that permits the maintenance of elastic deformation of the vibration damping member  31 . Therefore, the sleeve section  35  eliminates a possibility of having the vibration damping member  31  deformed into a height lower than the height H 12  and thereby resulting in a fall in the vibration damping characteristic thereof or in plastic deformation thereof. As a result, the sleeve section  35  guarantees that the vibration damping member  31  is maintained at a height between the height H 12  and the height H 11  and suitably shows the vibration damping performance thereof. 
     When the vibration damping member  31  is at the height H 12 , the sleeve section  35  transmits a pressing force to the shoulder section  18  of the insertion hole  15  through the upper surface of the plate bottom section  37 . Therefore, while the suitable lateral sliding ability of the plate  32  on the shoulder section  18  of the insertion hole  15  is maintained, the pressing force from the sleeve section  35  is evenly distributed across the shoulder section  18  through the plate  32 . This prevents occurrence of inconveniences such as an incident where, when the sleeve section  35  having a higher level of hardness than shoulder section  18  comes in direct contact with the shoulder section  18  formed of aluminum as a part of the cylinder head  12 , the shoulder section  18  is shaved or deformed. 
     Furthermore, the inner circumferential surface of the sleeve section  35  contacts the vibration damping member  31  but does not contact the coil spring  34 . That is, the vibration damping member  31  has the elastic member  36  toward the outer circumference of the coil spring  34 , and a part of the elastic member  36  that faces the outer circumference of the coil spring  34  abuts the sleeve section  35 . This eliminates a possibility that the vibration absorbing and vibration damping characteristics of the coil spring  34  are changed as a result of contact of the coil spring  34  with the sleeve section  35 . The vibration damping member  31  is capable of suitably displaying the vibration absorbing and vibration damping characteristics in a state where the influence from the sleeve section  35  is small. 
     Next, movement performed by the tolerance ring  33  in response to the pressing force is described. 
     When the force F from the tapered surface  24  of the fuel injection valve  11  is applied to the tolerance ring  33 , the force Fa acting in the direction along the axis parallel C 1  and the force Fb acting in the direction orthogonal to the axis parallel C 1  are applied to the ridgeline  47  of the tolerance ring  33  in accordance with the angle α of the tapered surface  24 . As a result, the force Fa acting in the direction along the axis parallel C 1  presses the vibration damping member  31  and, at the same time, is transmitted to the shoulder section  18  through the vibration damping member  31  and the plate  32 . At this time, the vibration damping member  31  tends to expand laterally, that is, in the radial direction along with decrease of the height thereof when being pressed by the force Fa. In other words, the inner circumferential surface of the vibration damping member  31  tends to expand toward the inner circumference, and the outer circumferential surface tends to expand toward the outer circumference, whereby forces acting toward the inner circumference and toward the outer circumference occur from the vibration damping member  31 . On this basis, a pressing force acting from the vibration damping member  31  toward the outer circumference is transmitted to the sleeve section  35  abutting the outer circumferential surface of the vibration damping member  31 . In other words, the sleeve section  35  forming the lower part of the tolerance ring  33  receives an outward acting force. 
     On the other hand, the force Fb that acts in the direction orthogonal to the axis parallel C 1  acts to enlarge the opening of the upper part of the tolerance ring  33  outward, as described above. 
     That is, in the force F received by the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11 , the force Fb acting in the direction orthogonal to the axis parallel C 1  acts to enlarge the upper part of the tolerance ring  33  toward the outer circumference, whereas the force Fa acting in the direction along the axis parallel C 1  presses the lower part of the tolerance ring  33  toward the outer circumference through the vibration damping member  31  in this embodiment. As a result, at least a part of the force Fb, which tends to enlarge the upper part of the tolerance ring  33 , is cancelled by a force with which the vibration damping member  31  presses the sleeve section  35  laterally. As a result, enlargement of the opening of the upper part of tolerance ring  33  is suppressed. In other words, in such a manner as to oppose a moment attributable to the force Fb, which tends to enlarge the upper part of the tolerance ring  33  in a direction that enlarges the opening thereof, a moment that acts in a reverse direction thereto attributable to a force acting from the vibration damping member  31  on the sleeve section  35 , which is the lower part of the tolerance ring  33 , comes to act on the tolerance ring  33 . This prevents the force Fb from unilaterally warping the tolerance ring  33 . 
     Additionally, since the stiffness (moment of inertia) of the tolerance ring  33  as a whole is improved by integration of the sleeve section  35  with the tolerance ring  33 , the opening of the upper part of the tolerance ring  33  is prevented from enlarging. Furthermore, in the lower part of the tolerance ring  33 , which is compressed and deformed (shrunken) along with enlargement of the opening of the upper part of the tolerance ring  33 , the sleeve section  35  integrally formed comes to have a structure opposing the compression and deformation thereof, and thereby performs the function of suppressing enlargement of the opening of the upper part of the tolerance ring  33 . 
     As described above, the vibration insulator of this embodiment brings about advantages as listed below. 
     (1) The stiffness of the tolerance ring  33  itself is increased by the sleeve section, which is formed integrally with the tolerance ring  33  and extends from the tolerance ring  33 . Therefore, improvement in durability of the tolerance ring  33  against the force Fb that is received by the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11  and acts to enlarge the opening of the tolerance ring  33  is enabled. This serves to prevent occurrence of warping of the tolerance ring  33 , and also to maintain the position of the tapered surface  24  of the fuel injection valve  11  abutting the tolerance ring  33 . That is, the fuel injection position of the fuel injection valve  11  is suitably maintained, and the combustion state is also appropriately maintained. 
     (2) When the elastic member  36  deforms by receiving a strong pressing force from the fuel injection valve  11 , the sleeve section  35  comes in contact with the shoulder section  18  through the plate  32 . On this basis, excessive deformation of the elastic member  36 , which might deform plastically when having deformed to a large extent, is restricted. That is, it is made possible to use the elastic member  36  while keeping the elastic member  36  from deforming beyond the extent (the range of H 11  to H 12  in terms of height of the elastic member  36 . The amount of deformation of the elastic member  36  is 0 to (H 11 −H 12 ) using the heights) that allows elastic deformation. This serves to suitably maintain the elasticity of the elastic member  36 , and maintain the vibration absorption and damping function using the elasticity. 
     (3) Excessive deformation of the elastic member  36 , the elasticity of which is adjusted by the coil spring  34 , is restricted by the sleeve section  35 . In other words, the elastic member  36  is used within a range (of H 11  to H 12  in terms of height) that enables elastic deformation thereof. This serves to suitably maintain the elasticity of the elastic member  36 , and maintain the vibration absorption and damping function using the elasticity thereof. 
     (4) While the elastic member  36 , which tends to deform in a manner radially expanding when being pressed, presses the sleeve section  35  toward the outer circumference, the abutting section  44  (the ridgeline  47 ) of the tolerance ring  33  receives from the fuel injection valve  11  the force Fb that acts in the direction that enlarges the opening of the abutting section  44 . That is, the tolerance ring  33  receives outward-acting forces at the abutting section  44  (the ridgeline  47 ) and the sleeve section  35 , respectively, whereby occurrence of warping is prevented as compared to a case where an outward-acting force is received only at the abutting section  44  (the ridgeline  47 ). Consequently, it is made possible to maintain the position, in the tapered surface  24  of the fuel injection valve  11 , at which the abutting section  44  of the tolerance ring  33  is abutted thereby. This serves to suitably maintain the fuel injection position of the fuel injection valve  11  with respect to the combustion chamber, and thereby also serves to maintain the most suitable combustion state. 
     (5) The relative position of the tolerance ring  33 , which cannot be easily joined strongly to the elastic member  36 , with respect to the elastic member  36  is defined by the plate  32  from the inner circumferential surface of the tolerance ring  33 . Therefore, appropriate stacking of the tolerance ring  33  on the elastic member  36  is facilitated, whereby improvement of the feasibility of the vibration insulator  30  as described herein is enabled. 
     (6) The outer circumferential edge of the plate  32  is molded into a shape where a burr, cut upward toward the elastic member  36 , appears. Therefore, even in a case where a bulge portion is formed in a region from the shoulder section  18  of the cylinder head  12  toward the inlet section  17 , the plate  32  is prevented from overriding or being caught by the bulge portion. This serves to form the size of the shoulder section  18 , formed in the insertion hole  15  of the cylinder head  12 , into the requisite minimum size that enables deviation of the axis C of the fuel injection valve  11  from the centered position to be compensated by movement of the vibration insulator  30 . 
     (7) A pressing force that acts on the fuel injection valve  11  is circumferentially evenly distributed when the annular tapered surface  24  abuts the annular abutting section  44  (the ridgeline  47 ). Therefore, compensating movement that responds to deviation of the axis C of the fuel injection valve  11  from the centered position is suitably performed. 
     Second Embodiment 
       FIG. 6  is an end view showing the structure of a vibration insulator  30  according to a second embodiment of the present invention. Since this embodiment differs from the first embodiment in structure of the vibration insulator  30  but the other structures are the same, differences from the first embodiment are mainly described, and description of members similar to those of the first embodiment is omitted by assigning the same reference signs thereto, for illustrative purposes. 
     As shown in  FIG. 6 , the vibration insulator  30  is formed by sequentially stacking a vibration damping member  31  and the tolerance ring  33  on a plate bottom section  37  of a plate  32 . 
     The vibration damping member  31  includes: an elastic member  36 A formed of rubber or the like, which is similar to the elastic member  36  described in the first embodiment; and an annular coil spring  34  embedded in the elastic member  36 A. In this embodiment, the outer circumferential surface of the elastic member  36 A covers the circumference of one turn of the helix of the coil spring  34  with a predetermined thickness, thereby being formed into an arcuate shape homothetic to an arc of one turn of the helix thereof. 
     A sleeve section  35 A of the tolerance ring  33  also has a circular ring-like shape extending along the outer circumferential surface of the vibration damping member  31  toward the plate  32  from a part of a ring bottom surface  40  that faces a ring outer circumferential surface  41 . In a cross-sectional view, the inner circumferential surface of the sleeve section  35 A is formed in an arcuate shape bowed at the center in the height direction thereof. The arcuate shape of this sleeve section  35 A is homothetic to the helix of the coil spring  34 , and is formed into a state where the arcuate outer circumferential surface of the elastic member  36 A is abutted thereby. Therefore, the arcuate outer circumferential surface of the elastic member  36 A comes to abut the arc-shaped inner circumferential surface of the sleeve section  35 A. That is, the outer circumferential surface of the coil spring  34  is opposed to the arc-shaped inner circumferential surface of the sleeve section  35 A through the predetermined-thickness portion of the elastic member  36 A. This serves to transmit a force from the outer circumferential surface of the coil spring  34  evenly to the arcuate inner circumferential surface of the sleeve section  35 A through the predetermined-thickness portion of the elastic member  36 A. 
     For example, suppose that, when a force from a tapered surface  24  of a fuel injection valve  11  is applied to the tolerance ring  33 , a force Fa acting in the direction along a axis parallel C 1  and a force Fb acting in the direction orthogonal to the axis parallel C 1  is applied to a ridgeline  47  of the tolerance ring  33  in accordance with an angle α of the tapered surface  24 . Then, when the coil spring  34  is vertically compressed by the force Fa acting in the direction along the axis parallel C 1  and deforms in a laterally expanding manner, a force that expands from the coil spring  34  toward the outer circumference is transmitted evenly to the arcuate inner circumferential surface of the sleeve section  35 A, which has a similar shape to the outer circumferential surface of the coil spring  34 , through the elastic member  36 A, which has an uniform thickness in the direction all along the circumference of the arc. As a result, a force that is generated by the deformation of the coil spring  34  and acts toward the outer circumference is more smoothly transmitted uniformly to the inner circumferential surface of sleeve section  35 A all along the vertically extending arc. In other words, a force that cancels a force that enlarges the opening of the upper part of the tolerance ring  33  occurs in a larger magnitude to the sleeve section  35 A. Additionally, the length of an arc, appearing in  FIG. 6 , of a contact surface of the outer circumferential surface of the vibration damping member  31  through which this outer circumferential surface comes in contact with the inner circumferential surface of the sleeve section  35 A is made longer. On this basis, the force from the vibration damping member  31  comes to be efficiently transmitted to the sleeve section  35 A. Further, the inner circumferential surface of the sleeve section  35 A has a structure surrounding the outer circumferential surface of the vibration damping member  31 , whereby it is also made possible for the inner circumferential surface of the sleeve section  35 A to receive a force from the outer circumferential surface of the vibration damping member  31  without fail. 
     Furthermore, since the stiffness of the tolerance ring  33  is improved by integration of the sleeve section  35 A with the tolerance ring  33 , the opening of the upper part of the tolerance ring  33  is prevented from enlarging. Further, in the lower part of the tolerance ring  33 , which is shrunk as the opening of the upper part of the tolerance ring  33  enlarges, the sleeve section  35 A forms a structure that resists such shrinkage. Also on this basis, enlargement of the opening of the upper part of the tolerance ring  33  is suppressed. 
     As described above, this embodiment not only brings about advantages that are the same as or similar to the above advantages (1) to (7) of the first embodiment described above, but also brings about advantages as listed below. 
     (8) A force generated from the outer circumferential surface, having an arcuate shape in a cross section, of the elastic member  36 , which deforms toward the outer circumference by being pressed, is transmitted to the inner circumferential surface, having an arcuate shape in a cross section, of the sleeve section  35 A without being dispersed. Therefore, when having deformed, the elastic member  36  presses the sleeve section  35 A with a stronger force toward the outer circumference. As a result, warping of the tolerance ring  33 , which is caused by a force received by the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11 , is suppressed to a greater extent. Therefore, it is made possible to maintain, in the tapered surface  24  of the fuel injection valve  11 , a position that abuts the abutting section  44 . 
     Third Embodiment 
       FIG. 7  is an end view showing the structure of a vibration insulator  30  according to a third embodiment of the present invention. Since this embodiment differs from the first embodiment in structure of the vibration insulator  30  but the other structures are the same, differences from the first embodiment are mainly described, and description of members similar to those of the first embodiment is omitted by assigning the same reference signs thereto, for illustrative purposes. 
     As shown in  FIG. 7 , the vibration insulator  30  is formed by sequentially stacking a vibration damping member  31  and a tolerance ring  33  on a plate bottom section  37  of a plate  32 . 
     The vibration damping member  31  includes: an elastic member  362  formed of rubber or the like, which is similar to the elastic member  36  described in the first embodiment; and an annular coil spring  34  embedded in the elastic member  36 B. 
     The tolerance ring  33  includes: an inner sleeve section  35 B extending toward the plate  32  from a part of a ring bottom surface  40  in the inner circumference thereof and having a circular ring-like shape; and an outer sleeve section  35 C extending toward the plate  32  from another part of the ring bottom surface  40  in the inner circumference thereof and having a circular ring-like shape. The inner circumferential surface of the inner sleeve section  35 B is extended out toward the plate  32 , along a plate inner wall section  38 , in parallel to a axis parallel C 1 . On the other hand, the outer circumferential surface of the inner sleeve section  35 B is inclined relative to the axis parallel C 1 , so that the cross section of the inner sleeve section  358  is formed in a tapering, wedge shape. In other words, the thickness of the inner sleeve section  35 B is formed to be thicker toward the ring bottom surface  40  and thinner toward the plate  32 . 
     Additionally, the outer circumferential surface of the outer sleeve section  35 C is extended out toward the plate  32 , along a ring outer circumferential surface  41 , in parallel to the axis parallel C 1 . On the other hand, the inner circumferential surface of the outer sleeve section  35 C is inclined relative to the axis parallel C 1 , and the cross section of the outer sleeve section  350  is also formed in a tapering, wedge shape. In other words, the cross section of the outer sleeve section  35 C is formed to be thicker toward the ring bottom surface  40  and thinner toward the plate  32 . That is, the cross section of a space defined by the inner sleeve section  35 B and the outer sleeve section  35 C is a trapezoid shape, the size of the above space in the radial direction of the tolerance ring  33  sequentially becomes larger from the ring bottom surface  40  toward the plate  32 . 
     Further, in this embodiment, the vibration damping member  31  is formed into a cross-sectional shape of a trapezoid to be fitted in the space defined as described above and having a trapezoid shape, and is placed in the space. The vibration damping member  31  of this embodiment is also at the height H 11 . 
     For example, when the vibration damping member  31  is pressed by the force Fa in the direction along the axis parallel C 1  as a result of application of a force from the tapered surface  24  of a fuel injection valve  11  to the tolerance ring  33 , deformation of the vibration damping member  31  is suppressed by the ring bottom surface  40 , the inner sleeve section  35 B and the outer sleeve section  35 C, which surround the circumference of the vibration damping member  31 . On this basis, a force that tends to deform the vibration damping member  31  acts as a force (a reactive force) that presses back the ring bottom surface  40  upward. Therefore, a part of a downward acting force Fa, which acts on the tolerance ring  33  and acts in the direction along the axis parallel C 1 , is cancelled. 
     Furthermore, when being pressed by the force Fa in the direction along the axis parallel C 1 , the vibration damping member  31  deforms to become lower in height, which prompts the inner circumferential surface thereof to tend to expand toward the inner circumference and prompts the outer circumferential surface to expand toward the outer circumference. However, such expansion is suppressed by the inner sleeve section  35 B and the outer sleeve section  35 C. Therefore, both of a force that presses the vibration damping member  31  from the inner circumferential surface thereof toward the outer circumference and a force that presses the vibration damping member  31  from the outer circumferential surface thereof toward the inner circumference act on the vibration damping member  31 . That is, when the coil spring  34  is pressed downward and going to deform to expand laterally, a force of the coil spring  34  going to expand toward the inner circumference acts on the inner sleeve section  35 B, and a part of this force acts as a force that presses the inner sleeve section  35 B upward in accordance with the slope of the inner sleeve section  35 B. This also serves to cancel a part of the force, which acts on the tolerance ring  33  and acts in the direction along the axis parallel C 1 . Additionally, a force of the coil spring  34  going to expand to the outer circumference acts on the outer sleeve section  35 C, and a part of the thus acting force acts as a force that presses the outer sleeve section  35 C upward in accordance with the slope of the outer sleeve section  350 . This also serves to cancel a part of the force, which acts on the tolerance ring  33  and acts in the direction along the axis parallel C 1 . 
     That is, forces that occur to the vibration damping member  31  when the tolerance ring  33  is going to deform the vibration damping member  31 , and act toward the inner circumference and toward the outer circumference are converted by the inner sleeve section  35 B and the outer sleeve section  35 C, which have sloping surfaces, respectively, into forces that act on the upper part of the tolerance ring  33 . Therefore, the height of the vibration damping member  31  is prevented from changing. As a result, the tolerance ring  33  is prevented from entering into the insertion hole  15  of cylinder head  12  more deeply than necessary. 
     Additionally, since the stiffness of the tolerance ring  33  is improved by integration of the inner sleeve section  35 B and the outer sleeve section  35 C with the tolerance ring  33 , the opening of the upper part of the tolerance ring  33  is prevented from enlarging. Furthermore, in the lower part of the tolerance ring  33 , which is shrunk as the opening of the upper part of the tolerance ring  33  enlarges, the inner sleeve section  35 B and the outer sleeve section  35 C formed integrally with the tolerance ring  33  form a structure that resist the shrinkage of the lower part of tolerance ring  33 . Also on this basis, the opening of the upper part of the tolerance ring  33  is prevented from enlarging. 
     As described above, this embodiment not only brings about advantages that are the same as or similar to the above advantages (1) to (7) of the first embodiment described above, but also brings about advantages as listed below. 
     (9) The elastic member  36  is sandwiched between the inner sleeve section  35 B and the outer sleeve section  35 C of the tolerance ring  33 . Therefore, a reactive force of the elastic member  36 , which occurs in response to a pressing force from the fuel injection valve  11  acts toward the tolerance ring  33  (upward) through the inner sleeve section  355  and the outer sleeve section  35 C. As a result, even when the tolerance ring  33  is pressed by the fuel injection valve  11 , the vertical position of the tolerance ring  33  with respect to the shoulder section  18  of the cylinder head  12  is maintained. Therefore, the fuel injection position, with respect to the combustion chamber, of the fuel injection valve  11  supported by the tolerance ring  33  is suitably maintained, and the most suitable combustion state is maintained as well. 
     (10) Forces (reactive forces) that have occurred to the elastic member  36  due to a pressing force from the fuel injection valve  11  and act toward the inner circumference and toward the outer circumference are converted, into reactive forces that resist the pressing force acting from the fuel injection valve  11 , in accordance with the sloping angles of the inner sleeve section  35 B and the outer sleeve section  35 C, which face each other such that the elastic member  36  is sandwiched therebetween. As a result, the vertical position of the tolerance ring  33  with respect to the shoulder section  18  of the cylinder head  12  is maintained. This also serves to suitably maintain, with respect to the combustion chamber, the fuel injection position of the fuel injection valve  11  supported by the tolerance ring  33 , and further serves to maintain the most suitable combustion state as well. 
     Fourth Embodiment 
       FIG. 8  is an end view showing the structure of a vibration insulator  30  according to a fourth embodiment of the present invention. Since this embodiment differs from the first embodiment in structure of the vibration insulator  30  but the other structures are the same, differences from the first embodiment are mainly described, and description of members similar to those of the first embodiment is omitted by assigning the same reference signs thereto, for illustrative purposes. 
     As shown in  FIG. 8 , the vibration insulator  30  is formed by sequentially stacking a vibration damping member  31  and a tolerance ring  33  on a plate bottom section  37  of a plate  32 . 
     The vibration damping member  31  includes: an elastic member  36 C formed of rubber or the like, which is similar to the elastic member  36  described in the first embodiment; and an annular coil spring  34  embedded in the elastic member  36 C. 
     A sleeve section  35 D of the tolerance ring  33  has a circular ring-like shape extending, along the inner circumferential surface of the vibration damping member  31 , toward the plate  32  from an inner circumferential part (a part that is closer to the inner circumference than an inner circumferential sloping surface  42  is) of a ring bottom surface  40 . The height of the sleeve section  35 D from the ring bottom surface  40  is H 12 . In other words, the distal end section of the sleeve section  350  is formed so that a gap (gap=H 11 −H 12 ) may be ensured between the distal end section and a plate bottom section  37  in the direction along a axis parallel C 1 . 
     As a result, since the stiffness of the tolerance ring  33  is improved by integration of the sleeve section  35 D with the tolerance ring  33 , the opening of the upper part of the tolerance ring  33  is prevented from enlarging. Furthermore, in the lower part of the tolerance ring  33 , which is shrunk as the opening of the upper part of the tolerance ring  33  enlarges, the sleeve section  350  is formed integrally with the tolerance ring  33 , thereby forming a structure that resists such shrinkage. Also on this basis, the opening of the upper part of the tolerance ring  33  is prevented from enlarging. 
     As described above, this embodiment not only brings about advantages that are the same as or similar to the above advantages (1) to (3) and (5) to (7) of the first embodiment described above, but also brings about advantages as listed below. 
     (11) Even the sleeve section  35 D, which extends from the inner circumferential part of the tolerance ring  33 , serves to improve the stiffness of tolerance ring  33 . Therefore, even when the tolerance ring  33  receives a force that acts to enlarge the opening of the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11 , improvement in durability of the tolerance ring  33  against this force is enabled. 
     Fifth Embodiment 
       FIG. 9  is an end view showing the structure of a vibration insulator  30  according to a fifth embodiment of the present invention. Since this embodiment differs from the first embodiment in structure of the vibration insulator  30  but the other structures are the same, differences from the first embodiment are mainly described, and description of members similar to those of the first embodiment is omitted by assigning the same reference signs thereto, for illustrative purposes. 
     In this embodiment, the distance from the upper surface of a plate bottom section  37  of a plate  32  to an outer surface  12 A of a cylinder head  12  is height H 12 , which is lower than height H 11  of the vibration damping member  31 . That is, the height between the outer surface  12 A of the cylinder head  12  and a shoulder section  18  of an inlet section  17  is set to a height obtained by adding the thickness of the plate  32  to the height H 12 . 
     As shown in  FIG. 9 , the vibration insulator  30  is formed by sequentially stacking the vibration damping member  31  and a tolerance ring  33  on the plate bottom section  37  of the plate  32 . 
     A vibration damping member  31  includes: an elastic member  36 D formed of rubber or the like, which is similar to the elastic member  36  described in the first embodiment; and the annular coil spring  34  embedded in the elastic member  36 D. 
     A sleeve section  41 A of the tolerance ring  33  is a circular ring-like shape extending from a ring outer circumferential surface  41  toward the outer side of the tolerance ring  33  in the radial direction. A lower surface  41 B of the sleeve section  41 A is formed as a surface continuing from the ring bottom surface  40 . The lower surface  41 B of the sleeve section  41 A projects toward the outer circumference, and goes over the inlet section  17 . The size of the sleeve section  41 A in the radial direction is set so that, even when the plate  32  slides on the shoulder section  18  in any direction in the range of 0 to 360 degrees in the radial direction (laterally), the outer circumferential surface of the sleeve section  41 A may exist on the outer surface  12 A of the cylinder head  12 . On this basis, a gap (gap=H 11 −H 12 ) is ensured between the lower surface  41 B of the sleeve section  41 A and the outer surface  12 A of the cylinder head  12 . 
     The above configuration guarantees that the vibration damping member  31  deforms between the height H 11  and the height H 12 , and the vibration damping member  31  displays suitable vibration damping performance. In other words, when the vibration damping member  31  is deformed and compressed into the height H 12  by receiving a high pressing force, the lower surface  41 B of the sleeve section  41 A abuts the outer surface  12 A of the cylinder head  12 . Therefore, the vibration damping member  31  is prevented from deforming into a height that is lower than the height H 12 . That is, deterioration in vibration damping performance of the vibration damping member  31  and plastic deformation of the vibration damping member  31  are prevented. 
     Additionally, since the stiffness of the tolerance ring  33  as a whole is improved by integration of the sleeve section  41 A with the tolerance ring  33 , the opening of the upper part of the tolerance ring  33  is prevented from enlarging. 
     As described above, this embodiment not only brings about advantages that are the same as or similar to the above advantages (1) to (3) and (5) to (7) of the first embodiment described above, but also brings about advantages as listed below. 
     (12) The stiffness of the tolerance ring  33  is improved also by the sleeve section  41 A extending out from the outer circumferential surface of the tolerance ring  33 . Therefore, improvement in durability of the tolerance ring  33  against a force that acts on the tolerance ring  33  from the tapered surface  24  of the fuel injection valve  11  to enlarge the opening of the tolerance ring  33  is enabled. Additionally, when the elastic member  36  is deformed into a crushed form, the sleeve section  41 A of the tolerance ring  33  abuts the cylinder head  12 . Therefore, excessive deformation of the elastic member  36  is restricted, whereby it is made possible to use the elastic member  36  within a range (a height of H 11  to H 12 ) that permits elastic deformation thereof. This serves to suitably maintain the elasticity of the elastic member  36  and to maintain the vibration absorption and damping function using the elasticity. 
     Each of the above embodiments may be modified, for example, in the following modes. 
     Each of the above embodiments shows, as an example, a case where the angle β 2  of the outer tapered surface  46  is an angle smaller than 90 degrees with respect to the axis parallel C 1 . However, the present invention is not limited to such a case, and the angle of the outer tapered surface may be an angle of 90 degrees with respect to the axis parallel C 1 . For example, as shown in  FIG. 10 , a ridgeline  47 A may be formed by an outer tapered surface  46 A and the inner tapered surface  45  with the angle of the outer tapered surface  46 A set to the angle β 12  of 90 degrees with respect to the shaft parallel center C 1 . In this case, formation of the outer tapered surface is easier, and flexibility in configuring such a vibration insulator is improved. 
     The third embodiment shown in  FIG. 7  shows, as an example, a case where a space defined by the inner sleeve section  35 B and the outer sleeve section  35 C has a cross-sectional shape of a trapezoid. However, the present invention is not limited to such a case, and the thickness of at least any one of the inner sleeve section and the outer sleeve section may be uniform from the ring bottom surface  40  through the distal end toward the plate  32 . For example, as shown in  FIG. 11 , both of an inner sleeve section  35 E and an outer sleeve section  35 F may have constant thicknesses from the ring bottom surface  40  through the distal end toward the plate  32 , respectively. In this case, a reactive force that occurs to the vibration damping member  31  when the vibration damping member  31  is going to deform by being pressed acts as a force that presses back the ring bottom surface  40 . Therefore, it is made possible to cancel a part of the force Fa applied to the tolerance ring  33  from the fuel injection valve  11  in the direction along the axis parallel C 1 . As a result, the height of the vibration damping member  31  is prevented from changing. In other words, the fuel injection valve  11  is prevented from entering into the insertion hole  15  of cylinder head  12  more deeply than necessary, with respect to the ridgeline of the tolerance ring  33 . This serves to increase flexibility in configuring the sleeve section, and also to improve flexibility in configuring such a vibration insulator. 
     Each of the above embodiments shows, as an example, a case where the vibration damping member  31  includes both of the elastic member  36  (or any one of  36 A to  36 D) and the coil spring  34 . However, the present invention is not limited to such a case, and is not limited to a vibration damping member of the exemplified structure. Any vibration damping member having a vibration absorbing and damping function may be used by the application of any vibration damping members formed of elastic materials of various kinds, springs of various kinds or combinations thereof. 
     Each of  FIGS. 1 to 8 , that is, the first to fourth embodiments shows, as an example, a case where the coil spring  34  and the sleeve section  35  (or any one of  35 A to  35 D) are spaced apart from each other. However, the present invention is not limited to such a case, and the coil spring may be configured to stay in contact with or to come in contact with the sleeve section. 
     An internal combustion engine to which this invention is applied may be either a gasoline engine or a diesel engine as long as the engine is an internal combustion engine of the in-cylinder injection system. 
     DESCRIPTION OF THE REFERENCE NUMERALS 
     
         
           10  fuel injection system 
           11  fuel injection valve 
           12  cylinder head 
           12 A outer surface 
           12 B inner surface 
           13  delivery pipe 
           14  fuel injection valve cup 
           14 A inner circumferential surface 
           15  insertion hole 
           16  distal end hole section 
           17  inlet section 
           18  shoulder section 
           19  medium hole section 
           20  large diameter section 
           21  medium diameter section 
           21 R ring 
           22  small diameter section 
           23  injection nozzle 
           24  tapered surface 
           25  sealing section 
           26  proximal relay section 
           26 J connector 
           27  proximal insertion section 
           28  proximal sealing section 
           30  vibration insulator 
           31  vibration damping member 
           32  plate 
           33  tolerance ring 
           34  coil spring 
           35 ,  35 A,  35 D sleeve section 
           35 B,  35 E inner sleeve section 
           35 C,  35 F outer sleeve section 
           36 ,  36 A,  36 B,  36 C,  36 D elastic member 
           37  plate bottom section 
           37 R burr section 
           38  plate inner wall section 
           39  plate cover section 
           40  ring bottom surface 
           41  ring outer circumferential surface 
           41 A sleeve section 
           41 B lower surface 
           42  inner circumferential sloping surface 
           43  joint section 
           44  abutting section 
           45  inner tapered surface 
           46 ,  46 A outer tapered surface 
           47 ,  47 A ridgeline