JP3965673B2 - Bound stopper - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a bound stopper suitably used in, for example, a suspension installed in an automobile.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, automobile suspensions incorporate a shock absorber or the like that absorbs vibration generated between a vehicle body and a wheel that is mounted so as to be relatively displaceable with respect to the vehicle body. Further, the shock absorber is usually provided with a bound stopper that regulates a large displacement greater than a predetermined value when a large vibration is input. As such a bound stopper, as shown in FIG. 7, four first to fourth blocks are formed in a thick cylindrical shape by a rubber elastic body, and are formed in an annular shape on the outer peripheral surface thereof and arranged in the axial direction. First to third outer annular recesses 35a to 35c that are divided into 31 to 34 and first to third inner annular recesses 16a to 16a that are annularly formed on the inner peripheral surfaces of the first to third blocks 31 to 33, respectively. 16c is known.
[0003]
The bound stopper includes a cylinder main body 51 having one end fixed to a connecting member (not shown) on the wheel side, and a cylinder rod that protrudes from the other end surface of the cylinder main body 51 so as to be extendable and contracted, and whose tip is fixed to the body frame 61. 52 is provided for the shock absorber. That is, the bound stopper is coaxially attached with the fourth block 34 held on the outer peripheral surface of the tip of the piston rod 52 by press-fitting the piston rod 52 of the shock absorber into the inner hole. As a result, the end surface on the fourth block 34 side of the bound stopper comes into contact with the coil spring seat 62 fixed to the vehicle body frame 61, and the end surface on the first block 31 side of the bound stopper is separated from the upper end surface of the cylinder body 51. Are arranged in opposition to each other.
[0004]
When a large vibration is input between the vehicle body frame 61 and the wheel in a direction in which the cylinder body 51 and the bound stopper approach, the upper end surface of the cylinder body 51 abuts against the first block 31 of the bound stopper and presses. By compressing the bounce stopper in the axial direction, a large relative displacement greater than a predetermined value between the coil spring seat 62 on the vehicle body frame 61 side and the cylinder body 51 on the wheel side is elastically restricted.
[0005]
The bound stopper is partitioned into four first to fourth blocks 31 to 34 in the axial direction by providing first to third outer annular recesses 35a to 35c on the outer peripheral surface thereof. The volumes of the first to fourth blocks 31 to 34 are set so as to gradually decrease from the fourth block 34 side toward the first block 31 side, thereby being positioned on the side in contact with the cylinder body 51. The first block 31 is set to have the softest spring characteristic.
[0006]
Moreover, the 1st-3rd inner side annular recessed part 36a-36c is each provided in the internal peripheral surface of the 1st-3rd blocks 31-33, The depth of these 1st-3rd inner side annular recessed parts 36a-36c is each provided. The first inner annular recess 36a provided in the first block 31 located on the side in contact with the cylinder body 51 is set to be deepest. As a result, the first block 31 has a U-shaped cross section and is formed to bend and deform more easily than the second to fourth blocks 31 to 34 when an axial load is input to the bound stopper. Yes.
[0007]
Therefore, this bounce stopper is soft at the initial stage when the cylinder body 51 is in contact with the cylinder body 51 as described above and receives a load in the axial direction. The bounce stopper gradually becomes stiff as the bounce stopper compresses and deforms. It is configured to demonstrate.
[0008]
When the bound stopper and the cylinder body 51 come into contact with each other, a hitting sound is likely to occur. Therefore, as disclosed in, for example, Japanese Patent Application Laid-Open No. 8-42624, a plurality of protrusions 39 arranged in the circumferential direction are provided on the end surface on the first block 31 side of the bound stopper that comes into contact with the cylinder body 51. .. , 39 are provided to reduce the occurrence of hitting sounds.
[0009]
[Problems to be solved by the invention]
By the way, the above-mentioned conventional bound stopper is provided with projections 39,... , 39 on the contact surface (end surface on the first block 31 side) with the cylinder main body 51 in order to improve the quietness of automobiles in recent years. The generation of hit sounds is reduced. However, as the generation of the hitting sound is reduced, it has been newly found that an abnormal noise “gut” different from the hitting sound is generated from the vicinity of the abutting portion slightly behind the hitting sound. It was. The generation mechanism of this abnormal noise has not yet been fully elucidated, but is presumed as follows.
[0010]
That is, when the bound stopper is pressed against the cylinder body 51, the first block 31 having the softest spring characteristics and the shape most easily deformed by shearing is deformed so as to bend at the center. Since the opposing surfaces facing each other in the axial direction of the first inner annular recess 36a are in pressure contact with each other, it is considered that abnormal noise is generated due to the adhesiveness of the rubber when the pressed opposing surfaces leave.
[0011]
This invention is made | formed in view of the said actual condition, and makes it the subject which should be solved to provide the bound stopper which can prevent generation | occurrence | production of unusual noise and can aim at the improvement of silence.
[0012]
[Means for solving the problems, actions and effects of the invention]
The bound stopper according to the first aspect of the present invention that solves the above problem is formed into a thick cylindrical shape by a rubber elastic body, and is annularly formed on an outer peripheral surface thereof and partitioned into a plurality of blocks arranged in the axial direction. In a bound stopper having an outer annular recess and an inner annular recess formed in an annular shape on the inner peripheral surface of the block located on the most end side, two axially opposed surfaces facing each other in the axial direction of the inner annular recess A plurality of first protrusions and a plurality of second protrusions are provided to protrude in the direction and spaced apart from each other in the circumferential direction, and the protrusion height of the first protrusion and the second protrusion is 1 mm or more. It adopts a means that is arranged so as to be opposed to each other in the axial direction and configured to be pressed against each other when an axial load is input.
[0013]
The bound stopper of the present invention is provided with an inner annular recess on the inner peripheral surface of the block located on the most end side. Therefore, when an axial load is input, the block on the one end side bends at the center. And the opposed surfaces facing each other in the axial direction of the inner annular recess are in pressure contact with each other. At this time, since the first projecting portion and the second projecting portion are respectively provided on the facing surface of the inner annular recess, the facing surfaces are only partially provided with the first projecting portion and the second projecting portion. Press contact. For this reason, the area of the pressure contact portion is reduced, and the total pressure contact area between the opposing surfaces is greatly reduced. As a result, when the input load to the bound stopper is subsequently released and the opposing surfaces of the inner annular recesses that are in pressure contact with each other are separated, no abnormal noise is generated. This is because the opposing surfaces of the inner annular recess are partly pressed only at the portion where the first and second protrusions are provided, so that when the opposing surfaces that are in contact with each other are separated, the adhesiveness of the rubber Therefore, it is considered that the generation of abnormal noise is greatly reduced.
[0014]
Therefore, the bound stopper according to the present invention has a large number of first protrusions and a large number of second protrusions that protrude in the axial direction and are spaced apart from each other on two opposing surfaces facing each other in the axial direction of the inner annular recess. The first protrusion and the second protrusion have a protrusion height of 1 mm or more and are arranged to face each other in the axial direction so that they are pressed against each other when an axial load is input. because it is, to prevent the occurrence of abnormal noise, it is possible to improve the quietness.
[0015]
The bound stopper of the present invention is formed in a thick cylindrical shape by a rubber elastic body. As a material for forming the rubber elastic body, for example, natural materials such as natural rubber, synthetic rubber, or blended rubber obtained by blending them can be used.
[0016]
The bound stopper of the present invention is partitioned into a plurality of blocks arranged in the axial direction by an outer annular recess formed annularly on the outer peripheral surface thereof. The formation position and number of outer annular recesses are appropriately selected and set according to the size and number of blocks. By varying the volume and shape of each block, the spring characteristics of each block can be made different. Usually, the block located on the most end side of the bound stopper, that is, the block located on the side contacting the approaching member is set so as to have the softest spring characteristic. The inner peripheral surface of the block located on the most end side is provided with an inner annular recess formed in an annular shape so that the spring characteristic of the block is softened. For example, the inner annular recess is formed in a shape having two opposed surfaces that are opposed in the axial direction, such as a V-shaped or U-shaped cross section. Such an inner annular recess can be provided not only on the block located on the most end side but also on the inner peripheral surface of another block.
[0017]
The 1st protrusion part and 2nd protrusion part in this invention are each provided in the two opposing surfaces which oppose in the axial direction of the inner side annular recessed part formed in the block located in the most end side. The first projecting portion and the second projecting portion can be formed by, for example, a projection projecting in a dot shape, a ridge extending in the centripetal direction or the circumferential direction of the inner annular recess, and the like. The first protrusions and the second protrusions are usually provided so that a plurality of the protrusions are scattered in the circumferential direction. In this case, the first projecting portion and the second projecting portion configured to be in pressure contact with each other when an axial load is input are equally spaced in the circumferential direction so that the press contact portions are uniform in the circumferential direction. It is preferable that they are arranged. Moreover, it is preferable that the 1st protrusion part and the 2nd protrusion part are provided in the part of 50% or less of the surface area of an inner side annular recessed part in order to acquire the better noise generation | occurrence | production prevention effect. Moreover, although the protrusion height of a 1st protrusion part and a 2nd protrusion part is based also on the magnitude | size of an inner side annular recessed part and the material of the rubber | gum which forms a 1st protrusion part and a 2nd protrusion part , in this invention, it is 1 mm or more. Is done.
[0018]
And the bound stopper which concerns on invention of Claim 2 is set to the part below 50% of the surface area of the said inner side annular recessed part in the invention of Claim 1 in which the said 1st protrusion part and the said 2nd protrusion part are provided. It adopts the means of being.
[0019]
According to this means, when the load is applied in the axial direction, the first protrusion and the second protrusion are configured to come into pressure contact with each other. It is suppressed to 50% or less of the surface area of the annular recess. Thereby, since the press-contact area of two opposing surfaces is reduced significantly, prevention of abnormal noise can be made more reliable.
[0020]
Moreover, the bound stopper which concerns on invention of Claim 3 WHEREIN: The means that the said 1st protrusion part and the said 2nd protrusion part are arrange | positioned at equal intervals in the circumferential direction in invention of Claim 1 or 2. Adopted.
[0021]
According to this means, since the press contact portions of the first protrusion and the second protrusion that are in pressure contact with each other when an axial load is input are uniform in the circumferential direction, the two opposing surfaces are the first protrusion and the second protrusion. The possibility of contact at a portion where no portion is provided is reduced, and the occurrence of abnormal noise can be more reliably prevented.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
Embodiment 1
FIG. 1 is a cross-sectional view taken along the axial direction of the bound stopper according to the present embodiment, and is a cross-sectional view taken along the line II of FIG. 2, and FIG. 2 is a cross-sectional view taken along the direction perpendicular to the axis of the bound stopper. FIG. 3 is a cross-sectional view taken along line II-II in FIG. 1, and FIG. 3 is an enlarged cross-sectional view showing the main part of the bound stopper.
[0024]
As shown in FIGS. 1 and 2, the bound stopper of the present embodiment is formed into a thick cylindrical shape by vulcanization molding of a rubber material (natural rubber), and is formed in an annular shape on the outer peripheral surface thereof. The first to third outer annular recesses 15a to 15c are divided into four first to fourth blocks 11 to 14 arranged in the axial direction. The volume of the 1st-4th blocks 11-14 is set so that it may become small gradually toward the 1st block 11 side from the 4th block 14 side, and the 1st block 11 located in the one end side is the most. It is set to have the softest spring characteristics. In the third block 13, a ring-shaped restraining member 13a is embedded in order to adjust the spring constant.
[0025]
Moreover, the 1st-3rd inner side cyclic | annular recessed part 16a-16c by which the cross section was formed in cyclic | annular form at the center part of each internal peripheral surface of the 1st-3rd blocks 11-13 is provided, respectively. Yes. The first inner annular recess 16a provided in the first block 11 is formed deeper than the second and third inner annular recesses 16b and 16c. Thereby, the first block 11 has a U-shaped cross section coupled with the fact that the outer peripheral portion of the opening end is formed in a tapered shape, and when the axial load is input to the bound stopper, It is formed so as to bend and deform more easily than the fourth blocks 12 to 14.
[0026]
Further, the two opposing surfaces facing each other in the axial direction of the first inner annular recess 16a have a large number of first projecting portions 17,... , 17 projecting in the axial direction from one facing surface, and shafts from the other facing surface. A number of second projecting portions 18,... , 18 projecting in the direction are provided. As shown in FIG. 3, the first protrusions 17,... , 17 and the second protrusions 18,... , 18 have a trapezoidal cross section extending in the centripetal direction from the vicinity of the bottom of the first inner annular recess 16a to the opening end. All are formed in the same size. The first protrusions 17,... , 17 and the second protrusions 18,... , 18 oppose each other in the axial direction and are arranged at equal intervals in the circumferential direction. Moreover, the 1st protrusion part 17, ... , 17 and the 2nd protrusion part 18, ... , 18 are provided in the 50% or less part of the surface area of the 1st inner side annular recessed part 16a.
[0027]
On the opening end face of the first block 11, four hemispherical projections 19,... , 19 provided for preventing sound hitting are arranged at equal intervals in the circumferential direction. Further, a ring-shaped holding portion 14a that protrudes in the centripetal direction and press-contacts with the outer peripheral surface of the piston rod that is inserted into the inner hole of the bound stopper is formed on the inner peripheral portion on the opening end side of the fourth block 14. Yes. The fourth block 14 is provided with an air vent passage 14b through which the air in the inner hole flows out to the outside when the bound stopper is compressed and deformed.
[0028]
As shown in FIG. 4, the bound stopper of the present embodiment configured as described above is attached to the shock absorber configured in the same manner as in the conventional case, as in the case of the conventional bound stopper. Used. That is, the bound stopper is coaxial with the holding portion 14a of the fourth block 14 held on the outer peripheral surface of the tip of the piston rod 52 by press-fitting the piston rod 52 of the shock absorber into the inner hole thereof. Mounted on. As a result, the end surface on the fourth block 14 side of the bound stopper comes into contact with the coil spring seat 62 fixed to the vehicle body frame 61, and the end surface on the first block 11 side of the bound stopper is separated from the upper end surface of the cylinder body 51. Are arranged in opposition to each other.
[0029]
When a large vibration is input between the body frame 61 and the wheel in a direction in which the cylinder body 51 and the bound stopper approach, the upper end surface of the cylinder body 51 abuts against the first block 11 of the bound stopper and presses the bound. When the stopper is compressed in the axial direction, a large relative displacement greater than a predetermined value between the coil spring seat 62 on the vehicle body frame 61 side and the cylinder body 51 on the wheel side is elastically restricted. At this time, the first block 11 having the softest spring characteristic and formed in a shape that is most easily deformed by shearing is deformed so as to be bent at the center, and is opposed to the first inner annular recess 16a in the axial direction. The two are in pressure contact.
[0030]
However, the first projecting portions 17,... , 17 and the second projecting portions 18,... , 18 that are opposed to each other in the axial direction and are arranged at equal intervals in the circumferential direction are opposed to the opposing surfaces of the first inner annular recess 16 a. , 17 and the first protrusions 17, 17 and the second protrusions 18 , 18, 18 are only in pressure contact with each other. Therefore, the portion where the opposing surfaces of the first inner annular recess 16a are in pressure contact with each other becomes small and dispersed, and the total pressure contact area between the opposing surfaces is greatly reduced. Thereby, when the input load to the bound stopper is subsequently released and the opposing surfaces that are in pressure contact with the inner annular recess 16a are separated from each other, no abnormal noise is generated. This is opposed surface each other of the first inner annular recess 16a, the first protrusion 17, ..., 17 and the second projecting portions 18, ..., only the portion 18 is provided since the partially pressed in, press When the facing surfaces that have been separated are not easily affected by the adhesiveness of the rubber, the occurrence of abnormal noise is considered to be greatly reduced.
[0031]
As described above, the bound stopper of the present embodiment has the first projecting portions 17,... , 17 and the second projecting portions 17 that contact each other when the axial load is applied to the opposing surfaces in the axial direction of the first inner annular recess 16 a. Since the protrusions 18,... , 18 are provided, the generation of abnormal noise can be prevented and the quietness can be improved.
[0032]
Further, in the bound stopper of the present embodiment, the first protrusions 17,... , 17 and the second protrusions 18,... , 18 are provided in a portion of 50% or less of the surface area of the first inner annular recess 16 a. Therefore, since the pressure contact area between the opposing surfaces of the first inner annular recess 16a is greatly reduced, it is possible to more reliably prevent the generation of abnormal noise.
[0033]
Moreover, since the 1st protrusion part 17, ... , 17 and the 2nd protrusion part 18, ... , 18 are arrange | positioned at equal intervals in the circumferential direction, the bound stopper of this embodiment is 1st protrusion part 17, ... , 17 and the second projecting portions 18, ..., since the pressure contact points between 18 becomes uniform in the circumferential direction, two opposite faces each other is first protruding portions 17, ..., 17 and the second projecting portions 18, ..., 18 The possibility of contact at a portion where no is provided is reduced, and the occurrence of abnormal noise can be more reliably prevented.
[0034]
In the present embodiment, the first projecting portions 17,... , 17 or the second projecting portions 18,... , 18 are provided on both surfaces of the two opposing surfaces facing each other in the axial direction of the first inner annular recess 16 a. However, the protruding portion may be provided only on one of the two opposing surfaces. In this case, by setting the protruding height of the protruding portion appropriately high, the same noise generation preventing effect as that obtained when the protruding portions are provided on both surfaces of the opposing surface can be obtained.
[0035]
[Embodiment 2]
5 is a cross-sectional view taken along the axial direction of the bound stopper according to the present embodiment, and is a cross-sectional view taken along the line VV of FIG. 6, and FIG. 6 is a cross-sectional view taken along the direction perpendicular to the axis of the bound stopper. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5.
[0036]
As shown in FIGS. 5 and 6, the bound stopper of the present embodiment has the same basic configuration as the bound stopper of the first embodiment, and the first protrusion 27 provided on the opposing surface of the first inner annular recess 16a. , ..., 27 and the second projecting portions 28, ..., only the shape of the 28 are different. Therefore, about the site | part etc. which are common in Embodiment 1, detailed description is abbreviate | omitted only by attaching | subjecting the same code | symbol as Embodiment 1, 1st protrusion part 27 ... different from Embodiment 1 , 27, and 2nd protrusion part 28, ... , 28 will be mainly described.
[0037]
The first protrusions 27,... , 27 and the second protrusions 28,... , 28 of the present embodiment are two opposing surfaces that face each other in the axial direction of the first inner annular recess 16a, as in the first embodiment. Are provided so as to protrude in the axial direction from one of the opposing surfaces. The first protrusions 27,... , 27 and the second protrusions 28,... , 28 are formed in a rectangular shape having a triangular cross section extending in the centripetal direction from the vicinity of the bottom of the first inner annular recess 16a to the opening end. Both end surfaces of the direction are inclined surfaces whose tops are inclined inward, and all are formed in the same size. The first protrusions 27,... , 27 and the second protrusions 28,... , 28 are arranged at equal intervals in the circumferential direction at positions facing each other in the axial direction, and have a surface area of the first inner annular recess 16a. It is the same as in the case of Embodiment 1 in that it is provided in a portion of 50% or less.
[0038]
The bound stopper of the present embodiment configured as described above is used by being attached to a shock absorber as in the case of the first embodiment. And also in the case of the bound stopper of this embodiment, the 1st protrusion part 27, ... , 27 and the 2nd protrusion part 28, ... , 28 are provided in the opposing surface which opposes in the axial direction of the 1st inner side annular recessed part 16a. Therefore, the same operations and effects as in the case of the first embodiment can be obtained, for example, the effect of preventing the occurrence of abnormal noise can be reliably obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view along the axial direction of a bound stopper according to Embodiment 1 of the present invention, and is a cross-sectional view taken along the line I-I in FIG.
2 is a cross-sectional view taken along the direction perpendicular to the axis of the bound stopper according to Embodiment 1 of the present invention, and is a cross-sectional view taken along the line II-II in FIG.
FIG. 3 is an enlarged cross-sectional view showing a main part of the bound stopper according to Embodiment 1 of the present invention.
FIG. 4 is an explanatory diagram showing an attached state of the bound stopper according to the first embodiment of the present invention.
5 is a cross-sectional view along the axial direction of a bound stopper according to Embodiment 2 of the present invention, and is a cross-sectional view taken along line VV in FIG.
6 is a cross-sectional view taken along the direction perpendicular to the axis of the bound stopper according to Embodiment 2 of the present invention, and is a cross-sectional view taken along line VI-VI in FIG.
FIG. 7 is an explanatory view showing a state where a conventional bound stopper is attached.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11, 31 ... 1st block 12, 32 ... 2nd block 13, 33 ... 3rd block 13a ... Restraint member 14, 34 ... 4th block 14a ... Holding part 14b ... Air vent passage 15a, 35a ... 1st outer side annular recessed part 15b, 35b ... second outer annular recesses 15c, 35c ... third outer annular recesses 16a, 36a ... first inner annular recesses 16b, 36b ... second inner annular recesses 16c, 36c ... third inner annular recesses 17, 27 ... first 1 protrusion 18, 28 ... 2nd protrusion 19, 39 ... projection 51 ... cylinder body 52 ... piston rod 61 ... body frame 62 ... coil spring seat

Claims (3)

An outer annular recess that is formed in a thick cylindrical shape by a rubber elastic body and is annularly formed on the outer peripheral surface thereof and partitioned into a plurality of blocks arranged in the axial direction, and an inner peripheral surface of the block that is positioned at the most end side In a bound stopper having an inner annular recess formed in a ring shape,
A large number of first protrusions and a large number of second protrusions are provided on two opposing surfaces facing each other in the axial direction of the inner annular recess, and project in the axial direction and spaced apart in the circumferential direction. The one projecting portion and the second projecting portion have a projecting height of 1 mm or more, are arranged to face each other in the axial direction, and are configured to be in pressure contact with each other when an axial load is input. Bound stopper. 2. The bound stopper according to claim 1, wherein the first protrusion and the second protrusion are provided in a portion of 50% or less of the surface area of the inner annular recess. The bound stopper according to claim 1 or 2, wherein the first protrusion and the second protrusion are arranged at equal intervals in the circumferential direction.

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