JP2010031970A - Hydraulic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a hydraulic shock absorber, which includes a bump cushion not causing deterioration in cushion function and a resin bearing not causing mechanical malfunction by a collision of the bump cushion, with improved versatility. <P>SOLUTION: A sheet member 6 formed in a ring-like shape is disposed between the bump cushion 4 disposed to surround an upper end of a rod 2 in a shock absorber body, and a resin bearing 1 disposed on the bump cushion 4 to be laminated on the bump cushion 4 and formed in a ring-like shape. In the sheet member 6, an inner peripheral side part forming a central opening 6a in which the rod 2 is inserted is opposed to a lower end of a tubular projection part 1a as a lower end part of an inner peripheral side part in the bearing 1 to prevent an upper end in the compressed bump cushion 4 from entering into the central opening 6a. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a hydraulic shock absorber, and more particularly, to a hydraulic shock absorber having a resin bearing that allows the upper end of a suspension spring interposed in the shock absorber body to rotate due to the compression operation of the shock absorber body. Regarding improvements.

  As a hydraulic shock absorber having a resin bearing that allows the upper end of a suspension spring interposed in the shock absorber body to rotate due to the compression operation of the shock absorber body or the like, it has become a clear prior art so far. There is no proposal based on patent literature.

  However, for example, the hydraulic shock absorber disclosed in Patent Document 1 has a bearing in which a detailed structure is omitted. Therefore, if the bearing is a resin bearing disclosed in Patent Document 2, As compared with the case where this bearing is made of metal, it is possible to realize weight reduction and cost reduction.

  However, in the proposal disclosed in Patent Document 1, the bearing is formed in an annular shape and is placed at the center portion of the spring receiver formed in a substantially dish shape that locks the upper end of the suspension spring. The spring receiver has a hole formed of a cylindrical portion that inserts the upper end portion of the rod body that constitutes the shock absorber main body and has the bump cushion at the upper end portion at the center portion.

  The bearing is disposed so as to be interposed in the cylindrical portion, and the hole has a diameter substantially the same as the diameter of the vertical hole in the shaft core portion of the lower bump cushion. Therefore, when the bump cushion is compressed by the most compression operation of the shock absorber main body, the upper end portion enters the hole.

  Further, in the bump cushion, when the most compressed shock absorber body starts to expand, the bump cushion moves backward so that the upper end portion of the bump cushion is extracted from the hole, and the backward movement and the invasion are repeated. In that case, the upper end portion of the bump cushion is damaged or broken, and the cushion function is lowered.

  Therefore, in the proposal shown in the drawing (FIG. 3) as a non-patent document, that is, the proposal previously made by the applicant of the present application, the bearing 1 made of resin is formed in an annular shape, and the lower end of the central portion is The cylindrical protrusion 1a is formed, and the cylindrical protrusion 1a is made of a steel plate and the upper end of the suspension spring S is engaged with the cylindrical protrusion 1a while passing through the upper end of the rod body 2 through the cylindrical protrusion 1a. At the center, it is inserted into the opening 3a.

Therefore, according to the proposal shown in this drawing, since the cylindrical protrusion 1a is present in the opening 3a of the opening at the center of the spring receiver 3, the upper end of the bump cushion 4 enters the opening 3a. Therefore, it is possible to avoid in advance the deterioration of the cushion function due to the damage of the upper end portion of the bump cushion 4 described above.
JP 2008-89151 A (see paragraphs 0015 and 0017 and FIG. 2 in the specification) JP 2002-257146 A (see abstract, paragraphs 0020, 0029 and FIGS. 1, 2 and 5 in the specification)

  However, in the proposal disclosed in the drawings as the above-mentioned non-patent documents, the opening 3a opened at the center of the spring receiver 3 that faces the upper end of the bump cushion 4 is the spring in the proposal disclosed in Patent Document 1. Since it is smaller than the receiving hole, it can be said that the upper end portion of the bump cushion 4 does not easily enter the opening 3a and the cushion function of the bump cushion 4 is not lowered. However, there is a concern that a new problem may occur.

  That is, in the proposal disclosed in the above drawings, since the cylindrical protrusion 1a formed at the lower end of the bearing 1 is inserted into the opening 3a of the opening at the center of the spring receiver 3, the shock absorber main body is present. Although there is no room for the upper end of the bump cushion 4 to enter the opening 3a at the time of the most compression, the upper end of the bump cushion 4 is pressed so as to collide with the cylindrical protrusion 1a.

  Therefore, since a situation occurs in which the upper end of the bump cushion 4 collides with the resin bearing 1, the mechanical failure is likely to occur compared to the case where the resin bearing 1 is made of metal. In the case of failure, the bearing function deteriorates or cannot function, and the rotational force generated when the suspension spring is compressed is transmitted to the mount M on the vehicle body side connected to the upper end of the rod body 2. .

  In the mount M to which this rotational force is propagated, a torsional force that is not set is received, which causes a problem that the predetermined durability is unnecessarily reduced.

  The present invention was devised in view of such a current situation, and an object of the present invention is to provide a bump cushion that does not cause a decrease in cushion function and to prevent mechanical failure due to bump bump collision. It is an object of the present invention to provide a hydraulic shock absorber that is optimally equipped with a resin bearing and is expected to improve its versatility.

  In order to achieve the above-described object, the structure of the hydraulic shock absorber according to the present invention basically includes a shock absorber main body that allows a rod body to be inserted into and retracted from a cylinder body side under the presence of a suspension spring, and the shock absorber. A bump cushion disposed so as to surround the upper end portion of the rod body in the main body, and an outer peripheral side portion having an opening that opposes the upper end of the bump cushion and allows the rod body to be inserted through the central portion. An outer peripheral side portion is disposed between the spring support that locks the upper end of the suspension spring and the mount side that is connected to the upper end of the rod body, and the shaft core portion on the inner peripheral side portion. And an annularly formed resin bearing that penetrates the rod body, and the bearing has a cylindrical projection at the lower end of the inner peripheral side portion, and the cylindrical projection is the rod body. While penetrating the above In the hydraulic shock absorber formed adjacent to the opening formed in the central portion of the thread receiving portion, the annular shape is formed between the inner peripheral side portion forming the opening of the central portion in the spring receiving portion and the upper end of the bump cushion. In the bump cushion described above, a seat member is disposed, and the seat member has a central opening through which the rod body penetrates at a central portion, and an inner peripheral side portion in the seat member forming the central opening is compressed. It is assumed that the upper end portion is prevented from entering the central opening.

  Therefore, in the present invention, since the sheet member is disposed between the upper end of the bump cushion and the cylindrical protrusion of the resin bearing disposed above the bump cushion, the bump cushion is compressed. Therefore, the upper end portion of the bump cushion to be compressed does not collide with the cylindrical protrusion portion of the resin bearing.

  As a result, even if the compression of the bump cushion is repeated, the upper end portion of the bump cushion does not enter the cylindrical projection portion side of the resin bearing and does not repeat the withdrawal, so that the spring support The upper end of the bump cushion does not come into contact with the inner peripheral edge, and there is no concern about the deterioration of the cushion function due to breakage or breakage at the upper end of the bump cushion.

  And in the cylindrical projection part in resin-made bearings, the inner peripheral side part which has this cylindrical projection part does not bear an axial direction force, ie, an outer peripheral side part is made into a main-body part, and an axial direction force is carried out. Therefore, the axial force from the compressing bump cushion does not act directly, and there is no concern about the mechanical failure in the bearing due to the axial force.

  Hereinafter, the present invention will be described based on the illustrated embodiment. In the hydraulic shock absorber according to the present invention, as shown in FIG. It has a shock absorber body that can be inserted.

  The shock absorber main body is formed, for example, in a double cylinder shape. Therefore, the cylinder body side has a cylinder body that is an inner cylinder (not shown) and an outer cylinder 5 that is disposed outside the cylinder body, and the rod body 2. Is connected to the cylinder body inside the outer cylinder 5 so as to be able to appear and retract.

  Although not shown, in this shock absorber body, a piston body is slidably accommodated in the cylinder body, and an extension side chamber and a pressure side chamber are defined in the cylinder body by the piston body. And the compression side chamber can communicate with each other via a damping means disposed on the piston body, and generates a predetermined damping force when the hydraulic oil passes through the damping means.

  Although not shown in the figure, in this shock absorber main body, a space between the outer cylinder 5 and the cylinder body is a reservoir chamber that exerts an air spring force, and this reservoir chamber is a pressure side chamber and a cylinder body in the cylinder body. When the hydraulic oil from the pressure side chamber in the cylinder body passes through the damping means of the base valve portion toward the reservoir chamber, it is possible to perform predetermined damping. Generate power.

  By the way, although not shown, when the shock absorber body is formed in a single cylinder type, the cylinder body is on the cylinder body side, and the rod body 2 is connected to the cylinder body so as to be able to protrude and retract. It has a free piston in series with the piston body, and exerts an air spring force by the expansion and contraction of the air chamber defined behind the free piston.

  Even in the shock absorber body formed in the single cylinder type, when the contained piston body slides in the cylinder body so as to be slidable in the cylinder body, the damping means of the piston body has a predetermined damping force. Is generated.

  On the other hand, in the hydraulic shock absorber according to the present invention, the shock absorber main body is laminated on the bump cushion 4 disposed so as to surround the upper end portion of the rod body 2 and on the upper end of the bump cushion 4. Thus, the spring receiver 3 that holds the upper end of the suspension spring S at the outer peripheral side while having the opening 3a through which the rod body 2 is inserted at the center portion, and the spring receiver 3 and the rod body 2 and the mount M side connected with the upper end of 2, and has an annularly formed resin bearing 1 that penetrates the rod body 2 through the shaft core portion.

  The bump cushion 4 is formed in an inverted truncated conical cylinder shape that converges the outer periphery toward the lower side while increasing the outer diameter on the upper end side and reduces the outer diameter on the lower end side to a small diameter. When compressed by the rise of the outer cylinder 5 which is the body side, it is possible to perform compression deformation that gradually collapses from the lower end side toward the upper end side.

  And when this bump cushion 4 carries out said compression deformation by inserting the upper end part of the rod body 2 in the vertical hole 4a which has in an axial center part, a lower end raises along the rod body 2, and lower end side At the same time, the upper end side is compressed to absorb the impact from the outer cylinder 5 side.

  As a material constituting the bump cushion 4, a material having a high elasticity may be selected. However, a material conventionally selected as a material constituting this type of bump cushion may be used.

  The spring receiver 3 is press-formed from a steel plate, is formed in a substantially circular shape having a width that allows the upper end of the suspension spring S to be locked, and has an opening 3a through which the rod body 2 is inserted.

  Incidentally, the outer peripheral side portion of the spring receiver 3 locks the upper end of the suspension spring S in a stable state, and in particular, prevents noise generation when the upper end of the suspension spring S is separated from the outer peripheral side portion. The vibration material S1 or the like is sandwiched between the upper end of the suspension spring S.

  By the way, this spring receiver 3 is seated on the upper end of the bump cushion 4 described above in appearance, but actually, it is placed on the upper end of the bump cushion 4, and the nut N is attached to the thread portion 2a of the rod body 2. When the mount M is fixedly connected to the upper end of the rod body 2, the seat is finally seated on the upper end of the bump cushion 4 in a fixed state.

  Incidentally, in the present invention, when the spring receiver 3 is seated on the upper end of the bump cushion 4, the sheet member 6 is disposed between the spring receiver 3 and the upper end of the bump cushion 4. The member 6 will be described later.

  The resin bearing 1 exhibits a predetermined bearing function like the conventional metal bearing, and does not have the specificity to take up the place where it operates. Made of resin material.

  The resin bearing 1 is formed in the same manner as the resin bearing 1 used in the hydraulic shock absorber as the preceding example shown in FIG. 3, and in particular, it is an annular body. The lower end portion of the inner peripheral side portion formed in a cylindrical shape that is continuous with the outer peripheral side portion is a cylindrical protrusion 1a.

  In brief, as shown in FIG. 2, the bearing 1 is disposed between the upper case 11, the lower case 12 disposed outside the upper case 11, and the upper case 11 and the lower case 12. The thrust sliding bearing piece 13 and the radial sliding bearing piece 14 are provided.

  The upper case 11 is formed of a resin material, and has a cylindrical portion 11a adjacent to the outer periphery of the rod body 2 and a flange portion 11b integrally connected to the upper end of the cylindrical portion 11a. A cylindrical portion 12a that is also formed of a resin material and is positioned outside the cylindrical portion 11a in the upper case 11, and a flange that is integrally connected to the upper end of the cylindrical portion 12a and positioned below the flange portion 11b in the upper case 11 Part 12b.

  The thrust slide bearing piece 13 is disposed between the flange portion 11b in the upper case 11 and the flange portion 12b in the lower case 12 while being formed in an annular shape with a resin material, and allows horizontal relative rotation between the two.

  The radial sliding bearing piece 14 is disposed between the cylindrical portion 11a in the upper case 11 and the cylindrical portion 12a in the lower case 12 while being formed in a cylindrical shape with a resin material, and allows relative rotation in the horizontal direction between the two. .

  And in this bearing 1, the outer peripheral side part which is an annularly formed main body part is formed by the flange part 11b in the upper case 11, the flange part 12b in the lower case 12, and the thrust slide bearing piece 13, and this outer periphery is formed. The side portion is a portion that receives an axial force in the vertical direction in the drawing.

  On the other hand, in the bearing 1, an inner peripheral side portion is formed by the cylindrical portion 11a in the upper case 11, the cylindrical portion 12a in the lower case 12, and the radial sliding bearing piece 14, and the inner peripheral side portion is formed as an outer periphery. Compared to the side portion, the portion is not subjected to the axial force or is less likely to be received.

  And the lower end part of this inner peripheral side part is made into the cylindrical projection part 1a in the resin-made bearings 1 which comprise this invention, and the lower end of this cylindrical projection part 1a is set to the inner peripheral side part of the sheet member 6 mentioned later Opposite.

  Therefore, since the bearing 1 formed as described above is first made of resin, it is advantageous in terms of weight reduction and cost reduction as compared with the case where it is made of metal. .

  Next, even if this bearing 1 is made of resin, it has a thrust sliding bearing piece 13 on the outer peripheral side portion which is a main body portion, so that rotation from the suspension spring S via the spring receiver 3 is performed. The force is not propagated to the mount M on the vehicle body side.

  And in this bearing 1, since the outer peripheral side part which is a main body part bears an axial force, the inner peripheral side part becomes a part not bearing an axial force. Even if a mechanical failure occurs, there is no risk of impairing the function of the bearing 1 as long as no mechanical failure occurs on the outer peripheral side.

  The resin-made bearing 1 having the cylindrical protrusion 1a has the cylindrical protrusion 1a in the opening 3a opened at the center of the spring receiver 3 with the rod body 2 passing through the shaft core. It is placed on the spring receiver 3 so as to be inserted.

  At this time, since the bearing 1 inserts the cylindrical protrusion 1a into the opening 3a of the spring receiver 3 while passing the rod body 2 through the shaft core portion, the spring receiver 3 is stabilized with respect to the rod body 2, and therefore The upper end of the suspension spring S that locks the upper end of the spring receiver 3 does not sway with respect to the rod body 2, so that it is possible to connect the mount M to the upper end of the rod body 2 after the operation without requiring labor for positioning. Make work easier.

  This is the same as in the case of the prior example shown in the above-mentioned drawings. However, in the proposal disclosed in Patent Document 1, the spring receiver swings only by placing the bearing on the spring receiver. In other words, it is difficult to prevent the upper end of the suspension spring from swinging. Therefore, when connecting the mount to the upper end of the rod body after the operation, it takes time to align the position and there is a problem that requires time and labor for the connection. .

  On the other hand, in the illustrated embodiment, when the bearing 1 is disposed on the spring receiver 3 which is a predetermined position, the outer periphery side portion, which is the main body portion of the bearing 1, and the lower spring receiver 3 are arranged. Is provided with an annular washer 7 to ensure the unity between the spring receiver 3 and the lower body of the bearing 1.

  Incidentally, the cylindrical projection 1a of the bearing 1 is present inside the inner peripheral side portion of the washer 7, and the cylindrical projection 1a passes through the washer 7 and the spring receiver 3. The lower end is opposed to the upper end of the sheet member 6 to be described later, that is, as shown in the figure, an annular gap A is provided between the lower end of the cylindrical projection 1a and the inner peripheral side portion of the sheet member 6, The lower end of the projection 1 a is separated from the upper end of the sheet member 6.

  Accordingly, as will be described later, even if an axial force from the bump cushion 4 acts on the seat member 6, the axial force acts on the outer peripheral side portion of the bearing 1 and is not transmitted to the inner peripheral side portion. Therefore, it is prevented beforehand that the inner peripheral side portion of the bearing 1 receives the above-described axial force to cause a mechanical failure.

  By the way, the sheet member 6 is formed in an annular shape by press forming from a steel plate. Basically, when the bump cushion 4 is compressed by being seated on the upper end of the bump cushion 4, the upper end portion of the bump cushion 4 is Intrusion to the above-described cylindrical protrusion 1a side is prevented.

  Therefore, in the present invention, since the sheet member 6 seated on the upper end of the bump cushion 4 prevents the upper end of the bump cushion 4 from protruding upward, the bump cushion 4 is compressed and the upper end is compressed. As a result, the axial force at that time is not propagated to the lower end of the cylindrical projection 1a above the sheet member 6.

  Even when the annular gap A between the cylindrical projection 1a and the sheet member 6 is eliminated and the lower end of the cylindrical projection 1a is in light contact with the upper end surface of the sheet member 6, it is made of resin. When the bearing 1 is in a state where it can be absorbed by the elasticity of the bearing 1, the above axial force is not transmitted to the vehicle body side.

  On the other hand, the sheet member 6 is required to be fixed to the upper end of the bump cushion 4 as described above. Therefore, in the illustrated case, the outer peripheral side portion wraps around the outer peripheral side portion of the bump cushion 4. Of course, the movement in the vertical direction is restricted, and the movement in the horizontal direction with respect to the upper end of the bump cushion 4 is restricted to ensure the fixing property.

  As described above, the movement of the sheet member 6 in the horizontal direction is restricted, so that the interference of the sheet member 6 with the rod body 2 can be suppressed, that is, the rod body 2 is opened through the central portion and inserted through the rod body 2. It is possible to make the inner diameter of the central opening 6 a close to the outer diameter of the rod body 2, and therefore the inner diameter of the central opening 6 a becomes smaller, so that the upper end of the bump cushion 4 is more effectively bulged upward. It becomes possible to stop.

  As shown in the figure, a flange-like base D1 of the dust boot D is sandwiched between the seat member 6 and the upper end of the bump cushion 4, and even though the base D1 is small, it absorbs shock. I play a role.

  Incidentally, when the dust boots D are equipped, it is assumed that the base D1 is sandwiched between the seat member 6 and the upper end of the bump cushion 4. As shown in the diagram, the anti-vibration material S1 may be extended.

  About the mount M connected to the upper end of the rod body 2, a well-known structure may be adopted. However, in the drawing, the shock absorber side metal fitting M1, the vehicle body side metal fitting M2, and both M1 and M2 are integrated. And an elastic body M3 to be connected.

  And the upper end of the rod body 2 is integrally connected with said shock absorber side metal fitting M1 by screwing of the nut N with respect to the thread part 2a.

  Therefore, in the hydraulic shock absorber in which the rod body 2 in the shock absorber body is connected to the mount M, the cylinder body side in the shock absorber body is connected to the axle side in the vehicle, so that the vehicle is traveling. The shock absorber main body and the suspension spring S absorb the road surface vibration input from the axle side, and when the shock absorber main body is in the most compressed state when the vehicle exceeds the road surface protrusion, the bump cushion 4 is compressed to reduce the impact. And keep the ride comfort in the vehicle.

  At this time, even if the upper end of the suspension spring S rotates in the horizontal direction, the bearing 1 is disposed between the spring receiver 3 that locks the upper end of the suspension spring S and the upper body mount M. The bearing 1 blocks the propagation of the rotational force from the suspension spring S to the vehicle body mount M, and does not apply an unexpected torsional force to the vehicle body mount M, so that the durability of the setting in the vehicle body mount M is unnecessarily reduced. I won't let you.

  At this time, since the upper end of the bump cushion 4 does not collide with the resin bearing 1 disposed above the bump cushion 4, even if the bump cushion 4 is repeatedly compressed, the upper end portion of the bump cushion 4 Will not enter the cylindrical protrusion 1a side of the bearing 1 made of resin and will not repeatedly retreat from it, and the upper end of the bump cushion 4 will not contact the inner peripheral end of the spring receiver 3. The cushion function is not deteriorated due to breakage or breakage at the upper end portion of 4, and even in the resin bearing 1, the axial force from the suspension spring S and the bump cushion 4 to which the inner peripheral side portion is compressed is not received. Therefore, no mechanical failure is caused.

FIG. 3 is a partial front view showing a partially broken upper end portion of the hydraulic shock absorber according to the embodiment of the present invention. It is a partial expansion longitudinal cross-sectional view which shows one Embodiment of a bearing. It is a figure which shows the hydraulic shock absorber as a prior example similarly to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Bearing 1a Cylindrical protrusion 2 Rod body 3 Spring receiving 3a Opening 4 Bump cushion 5 Cylinder side outer cylinder 6 Seat member 6a Central opening 7 Washer A Annular gap D Dust boot D1 Base M Mount S Suspension spring

Claims (5)

A shock absorber body that allows the rod body to be inserted into and retracted from the cylinder body side under the suspension spring, a bump cushion disposed so as to surround the upper end of the rod body in the shock absorber body, and the bump A spring receiver that opposes the upper end of the cushion and has an opening through which the rod body is inserted in the center portion, and that locks the upper end of the suspension spring on the outer peripheral side, and an upper end of the spring receiver and the rod body The outer peripheral side portion is disposed between the mount side and the shaft side of the inner peripheral side portion, and an annularly formed resin bearing that penetrates the rod body is provided between the mount side and the mount side. A hydraulic shock absorber having a cylindrical projecting portion composed of the lower end portion of the inner peripheral side portion and being exposed to an opening formed in the central portion of the spring receiver while penetrating the rod body. In the vessel A sheet member formed in an annular shape is disposed between an inner peripheral side portion that forms an opening in the central portion and an upper end of the bump cushion, and the sheet member penetrates the rod body in the central portion. A hydraulic shock absorber having a central opening and preventing an upper end portion of the bump cushion compressed by the inner peripheral side portion of the seat member forming the central opening from entering the central opening. vessel. 2. The hydraulic shock absorber according to claim 1, wherein an annular gap is formed between a lower end of the cylindrical protruding portion of the bearing and an inner peripheral side portion of the sheet member facing the cylindrical protruding portion. A washer is disposed between an inner peripheral side portion of the spring receiver and an outer peripheral side portion of the bearing, and the washer is formed by penetrating the cylindrical projection portion of the bearing in the center portion. The hydraulic shock absorber according to claim 1 or 2. An upper case having the cylindrical portion adjacent to the outer periphery of the rod body and a flange portion integrally connected to the upper end of the cylindrical portion, and the bearing in the upper case disposed outside the upper case. A lower case having a cylindrical portion positioned outside the cylindrical portion, a flange portion integrally connected to an upper end of the cylindrical portion and positioned below the flange portion in the upper case, and the upper case An axially-formed thrust slide bearing piece that is disposed between the flange portion in the lower case and the flange portion in the lower case and allows horizontal relative rotation between the two, the cylindrical portion in the upper case, and the above-mentioned A radial slide bearing piece formed in a cylindrical shape that is disposed between the cylindrical portion of the lower case and allows relative rotation in the horizontal direction between the two. The flange portion in the upper case, the flange portion in the lower case, and the thrust sliding bearing piece form an outer peripheral side portion, and the cylindrical portion in the upper case, the cylindrical portion in the lower case, and the radial slip 4. The hydraulic shock absorber according to claim 1, wherein an inner peripheral side portion is formed with the bearing piece, and a lower end portion of the inner peripheral side portion is formed as a cylindrical protrusion. 5. The hydraulic shock absorber according to claim 1, wherein a base portion of a dust boot is sandwiched between the seat member and an upper end of the bump cushion.

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