JP5377355B2 - Cab mount and cab mount device using the same - Google Patents

Description

  The present invention relates to a cab mount interposed between an automobile cabin (cab) and a chassis frame, and a cab mount device using the cab mount.

  Conventionally, sports multi-purpose vehicles (SUVs), automobiles such as trucks have adopted a frame structure, and a cabin is supported by a cab mount against a chassis frame on which traveling wheels are mounted by a suspension mechanism. It has a structure. As this cab mount, for example, a cylindrical vibration isolator as disclosed in JP 2008-261389 A (Patent Document 1) is generally employed, and the inner shaft member is attached to the cabin and the inner shaft member The first rubber elastic body is disposed between the upper plate and the chassis frame provided on the chassis. When a load is input in the approach direction (bound direction) between the cabin and the chassis frame, the first rubber elastic body is compressed and deformed, the load is elastically supported, and a damping action due to internal friction or the like occurs. It has come to be demonstrated.

  Incidentally, as shown in Patent Document 1, in the cab mount, the inner shaft member is inserted through a mounting hole formed in the chassis frame, and is disposed on the opposite side of the upper plate across the chassis frame. There is also known a sandwich type structure in which a lower plate is supported by an inner shaft member and a second rubber elastic body is disposed between the lower plate and the chassis frame. When a load is input in the separation direction (rebound direction) between the cabin and the chassis frame, the second rubber elastic body is compressed and deformed, the load is elastically supported, and a damping action due to internal friction or the like is exerted. It has come to be demonstrated. As described above, in the cab mount, either one of the first rubber elastic body and the second rubber elastic body is compressed when one of the first rubber elastic body and the second rubber elastic body is compressed and deformed. This prevents the input in the pulling direction from acting on the surface and ensures durability.

  However, in the structure in which the chassis frame is sandwiched between the first and second rubber elastic bodies in this way, the first rubber elastic body spring and the second rubber elastic body are applied to any load input in the bound direction and the rebound direction. A rubber elastic spring acts in cooperation. Therefore, tuning of spring characteristics was difficult.

JP 2008-261389 A

  The present invention has been made in the background of the above-described circumstances, and the solution is to tune the spring characteristics easily and with high accuracy, and to realize excellent riding comfort performance. It is to provide a cab mount having a novel structure.

  Also, a cab mount device having a novel structure that can further improve riding comfort performance by devising an arrangement structure of a plurality of cab mounts including a cab mount having a specific structure according to the present invention described above. Is also an object of the present invention.

  According to a first aspect of the present invention, an upper plate that protrudes from the upper end in the axial direction on the cabin side to the outer peripheral side is provided with respect to an inner shaft member that is attached to the cabin, and is externally attached to the inner shaft member. A cylindrical rubber elastic body is disposed between the opposed surfaces of the chassis frame and the upper plate, and the cabin support load by the chassis frame is an axial compressive load with respect to the rubber elastic body. The inner shaft member is inserted into a mounting hole formed in the chassis frame, protrudes from the mounting hole to the side opposite to the cabin, and protrudes from the mounting hole. A lower plate protruding outward is provided at the lower end of the shaft member in the axial direction, and a buffer rubber is disposed on the surface of the lower plate facing the chassis frame. The shock-absorbing rubber is opposed to the chassis frame so as to be spaced downward in the axial direction, while the main rubber elastic body is superposed non-adheringly to at least one of the chassis frame and the upper plate. And a cylindrical seal rubber covering the outer peripheral surface of the inner shaft member protruding downward from the mounting hole is integrally formed with the main rubber elastic body and extends downward in the axial direction, and the lower end of the cylindrical seal rubber Is pressed against the lower plate and precompressed in the axial direction.

  In the cab mount having the structure according to the first aspect, the lower plate and the shock absorbing rubber face the chassis frame while being spaced apart downward. Therefore, when the cabin is displaced in a direction (bound direction) approaching the chassis frame in the vertical direction, it is possible to prevent the shock absorbing rubber spring from affecting the support spring characteristics in the bound direction. Thus, by configuring the support spring in the bounce direction only with the spring of the main rubber elastic body, the spring characteristics can be easily tuned in the bounce direction having a great influence on the riding comfort performance.

  The main rubber elastic body is not bonded to at least one of the chassis frame and the upper plate. Accordingly, it is possible to prevent a tensile load from acting on the main rubber elastic body when the cabin is displaced in a direction (rebound direction) away from the chassis frame in the vertical direction. Therefore, for example, it is possible to sufficiently ensure the durability of the main rubber elastic body while selecting a rubber material that can more advantageously realize a soft spring in the bound direction.

  In addition, when a large load is input in the rebound direction and the cabin and chassis frame are displaced greatly apart in the vertical direction, the lower plate abuts the chassis frame via cushioning rubber to cooperate with other cab mounts. Thus, the load is shared and supported. Thereby, it is possible to prevent another cab mount that supports the normal load in the rebound direction from being damaged due to excessive load concentration. In other words, in the cab mount of the present invention, a stopper mechanism is configured to buffer the relative displacement in the rebound direction between the cabin and the chassis frame using the contact between the lower plate and the chassis frame via the buffer rubber. Yes.

  Further, the lower end portion of the inner shaft member protruding from the mounting hole of the chassis frame is covered with the cylindrical seal rubber, and the lower end of the cylindrical seal rubber is pressed against the lower plate and pre-compressed in the axial direction. As a result, the space between the contact surfaces of the lower plate and the cylindrical seal rubber is sealed, and the lower end portion of the inner shaft member protruding from the mounting hole and the connecting portion of the inner shaft member and the lower plate are all made of the cylindrical seal rubber. It is separated from the outside. Therefore, foreign matter such as water and dust is prevented from adhering to the outer peripheral surface of the inner shaft member and entering the connecting portion between the inner shaft member and the lower plate, and the inner shaft member and the lower plate are corroded. Can be prevented.

  In addition, since the cylindrical seal rubber is integrally formed with the main rubber elastic body, the sealing function as described above by the cylindrical seal rubber can be easily realized without requiring an increase in the number of parts.

  According to a second aspect of the present invention, in the cab mount described in the first aspect, an insertion hole is formed in a central portion of the buffer rubber, and an axial lower end portion of the inner shaft member with respect to the insertion hole. Is inserted, and the lower end of the cylindrical seal rubber is in contact with the inner peripheral edge of the buffer rubber, and the cylindrical seal rubber is axially directed to the lower plate via the buffer rubber. The inner diameter of the insertion hole is made larger than the outer diameter of the inner shaft member, and the first annular seal protrusion is integrally formed on the inner peripheral surface of the insertion hole of the buffer rubber. The first annular seal protrusion is formed and pressed against the outer peripheral surface of the inner shaft member protruding downward in the axial direction from the mounting hole.

  According to the second aspect, in addition to the axial seal structure by the abutting of the cylindrical seal rubber and the lower plate, the direction perpendicular to the axis by the abutting of the first annular seal protrusion provided on the buffer rubber and the inner shaft member The seal structure is provided. Therefore, the entry of foreign matter into the connecting portion between the inner shaft member and the lower plate is more effectively prevented by the multiple seal structure.

  Further, since the cylindrical seal rubber is pressed against the lower plate via the inner peripheral edge portion of the buffer rubber, the cylindrical seal rubber and the lower plate are brought into close contact with each other without any gap, and the sealing performance can be improved.

  According to a third aspect of the present invention, in the cab mount described in the first or second aspect, an insertion hole is formed in a central portion of the buffer rubber, and an inner diameter dimension of the insertion hole is the inner shaft member. The lower end portion of the inner shaft member in the axial direction is inserted into the insertion hole, and the insertion hole has a larger diameter on the upper side in the axial direction than on the lower side in the axial direction. A stepped surface is formed at the inner peripheral edge of the buffer rubber, and the lower end in the axial direction of the cylindrical seal rubber is inserted into the large-diameter portion of the insertion hole. The cylindrical seal rubber is pressed in the axial direction against the lower plate via the inner peripheral edge of the buffer rubber by abutting with the surface in the axial direction.

  According to the third aspect, since the cylindrical seal rubber is pressed against the lower plate via the inner peripheral edge of the buffer rubber, the cylindrical seal rubber and the lower plate are more closely adhered to each other, and the sealing performance is improved. Can be illustrated. In addition, since the contact position between the cylindrical seal rubber and the buffer rubber is within the buffer rubber insertion hole and the periphery is surrounded by the buffer rubber, it is possible to prevent foreign matter from being sprayed directly onto the seal portion.

  According to a fourth aspect of the present invention, in the cab mount described in the third aspect, the inner diameter dimension of the large-diameter portion of the insertion hole is larger than the outer diameter dimension of the cylindrical seal rubber, and the insertion A second annular seal protrusion integrally formed on the inner peripheral surface of the buffer rubber protrudes radially inward from the large-diameter portion of the hole, and the second annular seal protrusion is the outer periphery of the cylindrical seal rubber. It is pressed against the surface.

  According to the fourth aspect, the second annular seal protrusion is pressed against the outer peripheral surface of the cylindrical seal rubber, so that the seal structure is configured. As a result, a multiple seal structure is realized in cooperation with the seal structure by the axial contact between the cylindrical seal rubber and the lower plate, and the entry of foreign matter is more effectively prevented.

  Further, the cylindrical seal rubber is in contact with the lower plate via the inner peripheral edge of the buffer rubber, and the cylindrical seal rubber and the second annular seal protrusion are both formed of a rubber elastic body. Therefore, each of the seal structures is configured with high adhesion by contact between the rubber elastic bodies, and excellent sealing performance is realized.

  According to a fifth aspect of the present invention, there is provided a cab mount device in which a cabin and a chassis frame that are spaced apart in the vertical direction are connected to each other by vibration isolation using a plurality of cab mounts, the position closest to the riding position in the cabin. The cab mount described in any one of the first to fourth aspects is adopted as the cab mount disposed on the vehicle, and at least one side in the vehicle front-rear direction with the cab mount interposed therebetween, A first rubber elastic body that is compressed by displacement of the cabin and the chassis frame in the approaching direction; and a second rubber elastic body that is compressed by displacement of the cabin and the chassis frame in the separation direction. It is characterized in that at least one cab mount is employed.

  According to the cab mount device having the structure according to the fifth aspect, by adopting the cab mount having the structure according to the present invention as the cab mount closest to the riding position having a large influence on the riding comfort performance, the spring characteristic in the bound direction at the riding position is obtained. Can be set easily, and the ride comfort experienced by the passenger is improved.

  On the other hand, in the cab mount device, it is necessary to support the load in the rebound direction, but here, the cab mount having the structure according to the present invention is rebounded by disposing another cab mount in a position away from the vehicle longitudinal direction. Directional load is supported. That is, the cab mount provided with both the first rubber elastic body compressed by the load input in the bounce direction and the second rubber elastic body compressed by the load input in the rebound direction has moved out of the boarding position. Arranged in position. As a result, the load in the rebound direction is supported without adversely affecting the riding comfort performance. It should be noted that at least one cab mount that supports the load in the rebound direction may be provided in consideration of the vibration mode and the like.

  In the present invention, the inner shaft member protrudes downward from the mounting hole of the chassis frame, and the lower plate is supported at a predetermined distance below the chassis frame, thereby providing a gap between the cushion rubber and the chassis frame. It was. This makes it possible to easily set the spring characteristics in the bounce direction, which has a large impact on the ride comfort, and improves ride comfort performance.When a large load is input in the rebound direction, the lower plate and chassis frame By abutting through the buffer rubber, it is possible to restrict the displacement of the cabin with respect to the chassis frame and prevent the load from being concentrated on other cab mounts. In addition, in order to realize the above effect, the lower end portion of the inner shaft member disposed below the chassis frame and the connecting portion between the inner shaft member and the lower plate are integrally formed on the main rubber elastic body. By separating from the external space by the cylindrical seal rubber, it is possible to prevent the inner shaft member and the lower plate from corroding due to intrusion and adhesion of water or the like.

The longitudinal cross-sectional view which shows the mounting state to the vehicle of the cab mount as one Embodiment of this invention. The longitudinal cross-sectional view of the main body rubber elastic body which comprises the cab mount shown by FIG. The longitudinal cross-sectional view which shows the state which attached the inner shaft member to the main body rubber elastic body shown by FIG. The longitudinal cross-sectional view which shows the lower plate with the shock absorbing rubber which comprises the cab mount shown by FIG. The perspective view which shows the arrangement | positioning state of the cab mount with respect to a chassis frame.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows a cab mount 10 for an automobile as an embodiment of the present invention. The cab mount 10 includes an inner shaft member 16 attached to the cabin 12 and a main rubber elastic body 18 attached to the chassis frame 14. It is mounted between the cabin 12 and the chassis frame 14 so that the cabin 12 is supported in an anti-vibration manner above the chassis frame 14. In the following description, the vertical direction means the vertical direction in FIG. 1 that is the vertical vertical direction in principle.

  More specifically, the inner shaft member 16 is a highly rigid member having a small-diameter cylindrical shape that linearly extends in the vertical direction, and an upper plate 20 is attached to the upper end thereof. The upper plate 20 has a substantially annular plate shape as a whole, is overlapped with the inner shaft member 16 from above on the same central axis, and is fixed to the inner shaft member 16 by means such as welding. Thus, the upper end of the inner shaft member 16 protrudes outward in the direction perpendicular to the axis in a manner like a flange. Further, a taper portion 22 that is inclined downward toward the radially outer side is provided at a radially outer intermediate portion of the upper plate 20, and the central portion and the outer peripheral edge portion of the upper plate 20 are displaced vertically. It spreads in a direction substantially perpendicular to the axis.

  The upper end surface of the inner shaft member 16 is overlapped with the cabin 12, and a mounting bolt 24 inserted from below into the center hole of the inner shaft member 16 is passed through a bolt hole 26 formed in the cabin 12. A nut 28 is screwed onto the mounting bolt 24 while projecting upward. Thereby, the inner shaft member 16 is fixed to the cabin 12 and extends downward in the axial direction.

  A main rubber elastic body 18 is externally inserted into the inner shaft member 16. As shown in FIG. 2, the main rubber elastic body 18 has a thick cylindrical shape as a whole, and has an inner diameter dimension larger than an outer diameter dimension of the inner shaft member 16. In addition, the main rubber elastic body 18 is formed with groove-shaped straight portions 30, 30 that open in the outer peripheral surface and extend in the circumferential direction at two locations that are spaced apart vertically in the axial direction. Further, in order to avoid a welded portion between the inner shaft member 16 and the upper plate 20, an annular counterbore portion 32 that opens upward is provided at the inner peripheral edge of the main rubber elastic body 18. The central hole is enlarged in diameter, and the main rubber elastic body 18 is thinned.

  Further, the central hole of the main rubber elastic body 18 has a larger diameter in the upper part in the axial direction than in the lower part. Further, the main rubber elastic body 18 is integrally formed with an annular upper end protrusion 34 projecting radially inward in the upper opening of the center hole, and radially inward in the lower part of the center hole. An annular intermediate protrusion 36 that protrudes toward the bottom is integrally formed.

  An insert member 38 is coaxially disposed and fixed to the lower end portion of the main rubber elastic body 18. The insert member 38 is a member made of a hard synthetic resin having a substantially annular shape, and is vulcanized and bonded in a state of being substantially embedded in the main rubber elastic body 18 below the lower straight portion 30. Yes. In the present embodiment, the concave grooves 40 are formed on the outer peripheral side and the lower side of the insert member 38 of the main rubber elastic body 18 at a plurality of locations on the circumference. The member 38 is exposed from the main rubber elastic body 18. Moreover, the hollow part as shown by Unexamined-Japanese-Patent No. 2008-261389 may be formed in the insert member 38, and the empty space may be formed.

  As shown in FIG. 3, the inner shaft member 16 is inserted into the center hole of the main rubber elastic body 18 having such an insert member 38. The inner shaft member 16 has an upper end protrusion 34 and an intermediate protrusion 36 that protrude into the center hole of the main rubber elastic body 18 and press against the outer peripheral surface of the inner shaft member 16, respectively. Is prevented from falling off and is positioned at the center in the direction perpendicular to the axis within the center hole of the main rubber elastic body 18.

  Further, an upper plate 20 fixed to the inner shaft member 16 is superposed on the upper surface of the main rubber elastic body 18 in a non-adhesive manner in the axial direction. The main body rubber elastic body 18 is thinned at the upper end by forming the countersunk portion 32 at the upper end of the main rubber elastic body 18 so that the initial contact area of the main rubber elastic body 18 with the upper plate 20 is reduced. Has been made smaller.

  On the other hand, as shown in FIG. 1, the lower end portion of the main rubber elastic body 18 to which the insert member 38 is fixed is mounted in a mounting recess 42 formed in the chassis frame 14 without being bonded. A main rubber elastic body 18 is interposed between the chassis frame 14 and the cabin 12 in the axial direction. The mounting recess 42 has a circular recess shape opened on the upper surface of the chassis frame 14, and the inner diameter thereof is the same as or slightly smaller than the outer diameter of the main rubber elastic body 18 at the fixing portion of the insert member 38. It has been enlarged. As a result, the main rubber elastic body 18 is attached to the attachment recess 42 with zero touch or a slight gap. Further, air is allowed to escape by the concave groove 40 formed in the contact portion of the main rubber elastic body 18 with the mounting concave portion 42, so that abnormal noise is prevented.

  In such a mounting state, the support load of the cabin 12 with respect to the chassis frame 14 is exerted on the main rubber elastic body 18 as an axial compressive load. Thereby, the main rubber elastic body 18 is pre-compressed in the axial direction between the opposed surfaces of the upper plate 20 and the bottom wall portion of the mounting recess 42.

  Further, a mounting hole 44 is formed in the bottom wall portion of the mounting recess 42 in the chassis frame 14, and the inner shaft member 16 projects downward from the chassis frame 14 through the mounting hole 44. Further, a cylindrical reinforcing projection 46 is integrally formed on the periphery of the opening of the mounting hole 44 in the chassis frame 14 by a bending process using a press or the like, and projects downward. The reinforcing protrusion 46 provides centering of the main rubber elastic body 18 and increases the rigidity of the cab mount 10 in the direction perpendicular to the axis (the vehicle left-right direction).

  A lower plate 48 is attached to the lower end portion of the inner shaft member 16 protruding downward from the mounting hole 44. As shown in FIGS. 1 and 4, the lower plate 48 is a high-rigidity member having a substantially annular plate shape, and is superimposed on the inner shaft member 16 from below on the same central axis. . As a result, the lower plate 48 is arranged in a flange-like manner protruding outward in the direction perpendicular to the axis at the lower end of the inner shaft member 16.

  A cushion rubber 50 is disposed on the upper surface of the lower plate 48. The buffer rubber 50 is a rubber elastic body having a thick, substantially annular shape, and an insertion hole 52 is formed in a central portion in the radial direction. The insertion hole 52 is a circular hole having an inner diameter dimension larger than the outer diameter dimension of the inner shaft member 16, and is formed through the buffer rubber 50 in the axial direction. Further, the insertion hole 52 has a stepped hole shape in which the inner diameter dimension is changed at the axially intermediate portion, and the axially upper side is a large-diameter portion 54 and the axially lower side is a small-diameter portion 56. . Furthermore, at the boundary between the large diameter portion 54 and the small diameter portion 56, an annular step surface 58 that extends in the direction perpendicular to the axis is formed on the inner peripheral edge of the buffer rubber 50.

  In addition, a first annular seal projection 60 and a second annular seal projection 62 projecting radially inward from the inner peripheral surface are integrally formed on the buffer rubber 50 at a predetermined distance in the axial direction. Each of the first and second annular seal protrusions 60 and 62 has a substantially constant cross-sectional shape narrowing in the axial direction toward the radially inner side, and is continuously formed over the entire circumference. The first annular seal protrusion 60 is formed so as to protrude radially inward at the upper end opening of the small diameter portion 56 of the insertion hole 52, and the second annular seal protrusion 62 is larger than the insertion hole 52. The upper end opening of the diameter portion 54 is formed so as to protrude inward in the radial direction. The inner diameter dimension of the first annular seal protrusion 60 is smaller than the outer diameter dimension of the inner shaft member 16, and the inner diameter dimension of the second annular seal protrusion 62 is smaller than the outer diameter dimension of the cylindrical seal rubber 64. It has been made smaller.

  The buffer rubber 50 having such a structure is vulcanized and bonded to the upper surface of the lower plate 48 and is disposed on the same central axis as the lower plate 48. Further, the outer peripheral surface and the outer peripheral portion of the lower surface of the lower plate 48 are covered with a rubber layer integrally formed with the buffer rubber 50. The buffer rubber 50 is formed as an integrally vulcanized molded product provided with a lower plate 48.

  As shown in FIG. 1, the lower plate 48 is fixed to the lower end portion of the inner shaft member 16 inserted into the insertion hole 52 of the buffer rubber 50 by the mounting bolt 24 inserted through the center hole. It faces the chassis frame 14 with a predetermined distance downward. Further, the shock absorbing rubber 50 fixed to the upper surface of the lower plate 48 also faces the chassis frame 14 while being spaced apart downward.

  Further, when the inner shaft member 16 is inserted into the small diameter portion 56 of the buffer rubber 50, the first annular seal projection 60 is pressed against the outer peripheral surface of the inner shaft member 16, and the inner shaft member 16 and the buffer rubber 50 are pressed. The gap between the radial directions is sealed.

  When the lower plate 48 is mounted, the inner shaft member 16 and the cylindrical seal rubber 64 covering the surface thereof are inserted into the insertion hole 52 of the buffer rubber 50. As shown in FIG. 2, the cylindrical seal rubber 64 is a substantially cylindrical rubber elastic body that is integrally formed with the main rubber elastic body 18 and protrudes downward, and gradually increases in thickness as the upper end portion goes upward. It is meat. Further, two annular lower end protrusions 66 projecting radially inward are formed in the axially intermediate portion of the cylindrical seal rubber 64 so as to be spaced apart from each other in the axial direction, and are inserted into the cylindrical seal rubber 64. The shaft member 16 is in contact with the lower end protrusions 66, 66, so that the inner shaft member 16 is prevented from falling off during component conveyance, and is positioned at the center in the direction perpendicular to the shaft.

  Further, as shown in FIG. 3, the cylindrical seal rubber 64 covers the outer peripheral surface of the lower end portion of the inner shaft member 16 by inserting the inner shaft member 16 into the center hole of the main rubber elastic body 18. It is arranged as follows. Thus, in a state where the main rubber elastic body 18 is attached to the inner shaft member 16, the cylindrical seal rubber 64 protrudes below the inner shaft member 16 by a predetermined length: H.

  The outer diameter dimension of the cylindrical seal rubber 64 is smaller than the inner diameter dimension of the large diameter portion 54 of the insertion hole 52 formed in the buffer rubber 50. Thus, when the lower plate 48 is attached to the inner shaft member 16, the cylindrical seal rubber 64 is inserted into the large-diameter portion 54 of the insertion hole 52 of the buffer rubber 50.

  Furthermore, the outer diameter dimension of the cylindrical seal rubber 64 is larger than the inner diameter dimension of the second annular seal protrusion 62 formed to protrude from the buffer rubber 50. As a result, the cylindrical seal rubber 64 is inserted into the large-diameter portion 54 of the insertion hole 52, whereby the second annular seal protrusion 62 is pressed against the outer peripheral surface of the cylindrical seal rubber 64, and the buffer rubber 50 and the cylindrical shape are pressed. Between the radial directions of the seal rubber 64 is automatically sealed.

  Further, when the lower plate 48 is attached to the inner shaft member 16, the lower end surface of the cylindrical seal rubber 64 is brought into contact with the step surface 58 of the buffer rubber 50 in the axial direction. Then, when the inner shaft member 16 is fixed with bolts in contact with the lower plate 48, the cylindrical seal rubber 64 is attached to the lower plate 48 via the buffer rubber 50 as shown in FIG. Are pressed in the axial direction and compressed in the axial direction so that the lower end thereof is positioned above the lower end of the inner shaft member 16. As a result, the stepped surface 58 of the cylindrical seal rubber 64 and the buffer rubber 50 is in close contact with the axial direction with sufficient contact force, and the space between the cylindrical seal rubber 64 and the buffer rubber 50 in the axial direction is sealed. Furthermore, since a sufficient amount of pre-compression is ensured, it is not separated by vibration input during normal travel, and the sealing performance is maintained.

  In the cab mount 10 having such a structure, the support spring that affects the spring characteristics when the cabin 12 and the chassis frame 14 are relatively displaced in the approaching direction is constituted only by the main rubber elastic body 18. Therefore, not only the compression spring of the rubber elastic body positioned on the upper side of the chassis frame 14 but also the tension spring of the rubber elastic body positioned on the lower side of the chassis frame 14 affects the spring characteristics in the bound direction. Compared with the cab mount, the spring characteristics in the bound direction can be tuned easily and with high accuracy.

  The main rubber elastic body 18 is attached to the inner shaft member 16 by non-adhesion and is attached to the upper plate 20 and the chassis frame 14 in a non-adhesive manner in the axial direction. When the load is input in the rebound direction, tensile deformation of the main rubber elastic body 18 is avoided. Thus, since the main rubber elastic body 18 functions as a compression spring without receiving a load in the tensile direction, the durability of the main rubber elastic body 18 is advantageously ensured. Accordingly, the rubber material of the main rubber elastic body 18 can be selected more freely. For example, by using a softer rubber material, the ride performance can be further improved and sufficient durability can be ensured. Is also possible.

  Further, when the input load in the rebound direction is a shockingly large load, the lower plate 48 fixed to the cabin 12 via the inner shaft member 16 causes the shock absorbing rubber to the chassis frame 14. 50 to contact. Thereby, the load in the rebound direction is shared and supported by the cab mount 10, and the input energy is reduced by the damping action of the buffer rubber 50. In addition, since the reinforcement protrusion 46 is formed in the contact part with the lower plate 48 in the chassis frame 14, the deformation | transformation of the chassis frame 14 by the contact with the lower plate 48 is prevented.

  In order to realize these effects as described above, the lower plate 48 needs to be held at a position spaced downward from the chassis frame 14 by the inner shaft member 16, but the inner shaft member 16 is held at the chassis frame 14. When projecting downward from the mounting hole 44, foreign matter such as water and dust may adhere to the outer peripheral surface of the inner shaft member 16 and the connecting portion between the inner shaft member 16 and the lower plate 48.

  Therefore, in the cab mount 10, the cylindrical seal rubber 64 is attached to the lower end portion of the inner shaft member 16 protruding downward from the mounting hole 44, and the cylindrical seal rubber 64 is pressed against the step surface 58 of the buffer rubber 50. Thus, the lower end portion of the inner shaft member 16 is covered with the cylindrical seal rubber 64 and the buffer rubber 50 so as not to be exposed to the outside. Therefore, it is possible to avoid the problem of dirt and erosion due to foreign matters adhering to the outer peripheral surface of the inner shaft member 16 and the connecting portion between the inner shaft member 16 and the lower plate 48. In particular, the connection portion between the inner shaft member 16 and the lower plate 48 in which prevention of corrosion is important is sealed against the external space by the axial contact between the cylindrical seal rubber 64 and the buffer rubber 50. Corrosion of the contact surface between the inner shaft member 16 and the lower plate 48 is effectively prevented.

  Further, the lower end portion of the cylindrical seal rubber 64 is inserted into the large diameter portion 54 of the insertion hole 52 of the buffer rubber 50, and the second annular seal protrusion 62 of the buffer rubber 50 presses against the outer peripheral surface of the cylindrical seal rubber 64. As a result, a seal mechanism in the direction perpendicular to the axis is formed. Accordingly, the lower end portion of the inner shaft member 16 and the radial center portion of the lower plate 48 are more advantageously sealed from the external space, and corrosion of the inner shaft member 16 and the lower plate 48 is effectively prevented.

  Furthermore, the lower end portion of the inner shaft member 16 is inserted into the small diameter portion 56 of the insertion hole 52 of the buffer rubber 50, and the first annular seal protrusion 60 of the buffer rubber 50 presses against the outer peripheral surface of the inner shaft member 16. It has been. As a result, the sealing performance can be further improved, and the connecting portion between the inner shaft member 16 and the lower plate 48 can be protected from the external environment.

  As described above, the cab mount 10 has a triple seal structure in which an axial seal mechanism and an axial perpendicular seal mechanism are combined. Therefore, while adopting a structure in which a gap is formed between the shock absorbing rubber 50 and the chassis frame 14 in order to improve the vibration proof performance in the bound direction and to realize a stopper function when a heavy load is input in the rebound direction. Corrosion caused by adhesion of water droplets to the inner shaft member 16 and the lower plate 48 is sufficiently avoided.

  Further, for example, even with the same main rubber elastic body 18, the cab mount 10 according to the present embodiment is more effective in the bound direction than the sandwich type cab mount that fastens the cabin 12 and the chassis frame 14 in the approaching direction. It is also possible to set a large stroke length.

  By the way, as shown in FIG. 5, the cab mount 10 is disposed between the cabin 12 and the chassis frame 14 at a specific position in the vehicle front-rear direction, thereby isolating the cabin 12 and the chassis frame 14 from each other. The cab mount device 90 having the structure according to the present invention to be connected is configured. The cab mount device 90 has a structure in which the cabin 12 and the chassis frame 14 are connected in a vibration-proof manner by the cab mount 10, the cab mount 70, and the cab mount 80. In the cab mount device 90, the left side in FIG. 5 is the front side of the vehicle and the right side in FIG. 5 is the rear side of the vehicle.

  The cab mount 70 basically has the same structure as that of the cylindrical antivibration support disclosed in Japanese Patent Application Laid-Open No. 2008-261389, and the chassis frame 14 is attached to a first rubber elastic body (first rubber Block) and a second rubber elastic body (second rubber block). The first rubber elastic body is compressed by the displacement of the cabin 12 and the chassis frame 14 in the approaching direction (bound direction), and in the separation direction (rebound direction) of the cabin 12 and the chassis frame 14. Due to this displacement, the second rubber elastic body is compressed. The cab mount 80 is a share type cab mount, and an inner shaft member attached to the cabin 12 and an outer cylinder member attached to the chassis frame 14 are connected by a main rubber elastic body vulcanized and bonded thereto. The main rubber elastic body undergoes compressive deformation and shear deformation due to the displacement of the cabin 12 and the chassis frame 14 in the approaching direction (bound direction). In short, the cab mounts 70 and 80 are structured to share and support the load when the normal load in the rebound direction is input. The cab mount 80 is set to have a harder spring characteristic than the cab mount 70.

  As shown in FIG. 5, the cab mount 10 having the structure according to the present embodiment is attached to the approximate center of the chassis frame 14 in the vehicle front-rear direction, and the other cab mounts 70 and 80 are cab mounts. 10 is disposed on both sides of the vehicle in the longitudinal direction.

  More specifically, the cab mount 10 is disposed at a position closest to the occupant's seating position in the cabin 12 in the vehicle longitudinal direction. A cab mount 80a is disposed on the front side (left side in FIG. 5) of the cab mount 10 at a predetermined distance from the cab mount 10, and the cab mount 70a is further forward than the cab mount 80a. Are arranged at a predetermined distance. On the other hand, a cab mount 70b is disposed on the rear side (right side in FIG. 5) of the cab mount 10 at a predetermined distance from the cab mount 10, and the cab mount 80b is further rearward than the cab mount 70b. Is arranged. In FIG. 5, the structure of the chassis frame 14 is shown in a simplified manner, but various frame structures such as a general ladder frame may be employed. In FIG. 5, the cabin 12 of the automobile is virtually shown as a two-dot chain rectangular parallelepiped. As is clear from FIG. 5, the cab mounts 10, 70, and 80 are arranged in the order described above with respect to the portion of the chassis frame 14 extending in the vehicle front-rear direction.

  In such a cab mount device 90, the cab mount 10 having a small spring constant in the bound direction is disposed as a mount for supporting the vicinity of the seating position where vibration transmission from the chassis frame 14 side to the cabin 12 is easily detected by the occupant. Yes. As described above, the cab mount 10 having an excellent vibration isolation function is particularly arranged at a position where it is desired to suppress the transmission of vibration, so that vibrations experienced by the occupant can be efficiently reduced, which is excellent. It is possible to achieve a comfortable ride performance.

  On the other hand, a pinch-type cab mount 70 and a shear-type cab mount 80 that can support a load in the rebound direction are disposed at a position far from the seating position of the occupant. That is, the cab mount 10 does not include a spring that supports a load in the rebound direction in order to achieve excellent vibration isolation performance in the bounce direction. Therefore, in the cab mount device 90 using the cab mount 10, the load in the rebound direction is supported by the other cab mounts 70 and 80 disposed at positions separated from the cab mount 10 in the front-rear direction. It has become.

  The cab mount 70 has a larger spring constant in the bound direction than the cab mount 10 in order to maintain excellent running stability. Further, in the cab mount 80, the main rubber elastic body is vulcanized and bonded to the inner shaft member and the outer cylindrical member, and the spring constant in the bound direction is set larger than that of the cab mount 10. However, since the cab mounts 70 and 80 are disposed at positions separated from the seating position, even if the vibration isolation performance in the bound direction is somewhat inferior to that of the cab mount 10, the ride comfort is greatly adversely affected. On the contrary, the running stability is improved by the stiffer spring. However, with respect to the cab mount 70a disposed at the front end of the vehicle, since the shared load of the cabin 12 acting is smaller than the shared load acting on other cab mounts including the cab mount 10, the rubber hardness is adjusted. The spring constant in the bound direction is set to be smaller than the spring constant in the same direction of the cab mount 10.

  As described above, in the cab mount device 90 of the present embodiment, the cab mount 10 having excellent vibration-proof performance is arranged near the seating position where the influence on the riding comfort is large, and on both the front and rear sides where the influence on the riding comfort is small. By arranging the cab mounts 70 and 80 having excellent load bearing performance, it is possible to achieve both improvement in ride comfort and ensuring running stability.

  As mentioned above, although embodiment of this invention was explained in full detail, this invention is not limited by the specific description. For example, the specific shape of the buffer rubber 50 is not particularly limited, and specifically, the insertion hole formed in the buffer rubber may not be a stepped hole shape.

  Further, the lower end surface of the cylindrical seal rubber 64 does not necessarily have to be pressed against the stepped surface 58 of the buffer rubber 50, for example, may be pressed against the upper surface of the buffer rubber 50, or may be pressed against the upper surface of the lower plate 48. It may be pressed directly. Particularly, when the stepped surface 58 is not formed on the buffer rubber and the insertion hole is a straight circular hole, the cylindrical seal rubber 64 is pressed against the upper surface of the buffer rubber or the upper surface of the lower plate 48. The desired sealing performance is ensured.

  In the embodiment, a structure in which the second annular seal protrusion 62 is formed so as to protrude from the inner peripheral surface of the buffer rubber 50 is shown. However, the inner peripheral surface of the buffer rubber 50 and the outer periphery of the cylindrical seal rubber 64 are shown. The sealing mechanism provided between the surface and the surface may be realized, for example, by forming an annular seal protrusion protruding from the outer peripheral surface on the cylindrical seal rubber 64 side and pressing it against the inner peripheral surface of the buffer rubber 50.

  Further, in the cab mount device 90, three types of cab mounts of cab mounts 10, 70, and 80 have been adopted, but there are more types of cab mounts having different structures depending on the required vibration-proof performance and load-bearing performance. A cab mount may be used. Of course, only two types of cab mounts including a cab mount having a structure according to the present invention may be employed. Further, the specific structure and tuning of the spring characteristics of the cab mounts 70 and 80 are merely examples. For example, the spring constant in the bounce direction of the cab mount 70 that is a sandwich type is the cab mount 10. It may be set smaller than the spring constant in the bounce direction.

10, 70, 80: Cab mount, 12: Cabin, 14: Chassis frame, 16: Inner shaft member, 18: Main rubber elastic body, 20: Upper plate, 44: Mounting hole, 48: Lower plate, 50: Buffer rubber 52: insertion hole, 58: step surface, 60: first annular seal protrusion, 62: second annular seal protrusion, 64: cylindrical seal rubber, 90: cab mount device

Claims (5)

An upper plate that protrudes from the upper end in the axial direction on the cabin side to the outer peripheral side with respect to the inner shaft member that is attached to the cabin is provided, and a cylindrical main body rubber elastic body that is extrapolated to the inner shaft member In a cab mount that is disposed between opposing surfaces of a chassis frame and the upper plate, and the load of supporting the cabin by the chassis frame is exerted as an axial compressive load on the main rubber elastic body,
The inner shaft member is inserted into a mounting hole formed in the chassis frame, protrudes from the mounting hole to the opposite side of the cabin, and is axially lower end of the inner shaft member protruding from the mounting hole. A lower plate is provided on the outer surface of the lower plate, and a shock absorbing rubber is disposed on a surface of the lower plate facing the chassis frame, and the shock absorbing rubber is separated from the chassis frame in the axial direction. While facing each other
A cylindrical sealing rubber covering the outer peripheral surface of the inner shaft member that protrudes downward from the mounting hole and the main rubber elastic body is non-adheringly superimposed on at least one of the chassis frame and the upper plate. A cab mount formed integrally with a main rubber elastic body and extending downward in the axial direction, wherein the lower end of the cylindrical seal rubber is pressed against the lower plate and pre-compressed in the axial direction.   An insertion hole is formed in the central portion of the cushioning rubber, and the lower end in the axial direction of the inner shaft member is inserted into the insertion hole, and the cylindrical shape is formed with respect to the inner peripheral edge of the cushioning rubber. The lower end of the seal rubber is in contact, and the cylindrical seal rubber is pressed against the lower plate in the axial direction via the buffer rubber, while the inner diameter of the insertion hole is the outer diameter of the inner shaft member The first annular seal protrusion is integrally formed on the inner peripheral surface of the insertion hole of the buffer rubber, and the first annular seal protrusion protrudes downward in the axial direction from the mounting hole. The cab mount according to claim 1, wherein the cab mount is pressed against the outer peripheral surface of the inner shaft member.   An insertion hole is formed in the central portion of the buffer rubber, and the inner diameter of the insertion hole is made larger than the outer diameter of the inner shaft member, and the lower end in the axial direction of the inner shaft member with respect to the insertion hole The insertion hole has a stepped hole shape in which the upper side in the axial direction has a larger diameter than the lower side in the axial direction, and a stepped surface is formed on the inner peripheral edge of the buffer rubber. The lower end of the cylindrical seal rubber in the axial direction is inserted into the large-diameter portion of the insertion hole and abuts the stepped surface in the axial direction so that the cylindrical seal rubber causes the inner peripheral edge of the buffer rubber to The cab mount according to claim 1, wherein the cab mount is pressed against the lower plate in the axial direction.   The inner diameter dimension of the large-diameter portion of the insertion hole is larger than the outer diameter dimension of the cylindrical seal rubber, and the second-diameter is integrally formed on the inner peripheral surface of the buffer rubber at the large-diameter portion of the insertion hole. The cab mount according to claim 3, wherein the annular seal protrusion protrudes radially inward, and the second annular seal protrusion is pressed against the outer peripheral surface of the cylindrical seal rubber. In a cab mount device in which a cabin and a chassis frame that are spaced apart in the vertical direction are connected to each other by vibration isolation using a plurality of cab mounts,
While the cab mount described in any one of Claims 1-4 is employ | adopted as a cab mount arrange | positioned in the position nearest to the boarding position in the said cabin,
At least one side of the vehicle front-rear direction across the cab mount is provided with a first rubber elastic body that is compressed by displacement of the cabin and the chassis frame toward each other, and a separation direction of the cabin and the chassis frame A cab mount device comprising at least one cab mount including a second rubber elastic body that is compressed by displacement of the rim.

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