JP2008215457A - Shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a further practical shock absorber for improving an outward appearance of the shock absorber, while restraining a cost increase. <P>SOLUTION: This shock absorber 20 is provided with an undercover 30 having a cylinder cover part 80 covering an upper part of a cylinder 40. The cylinder cover part 80 is formed so that a stain of a hydraulic fluid sticking to a wheel side adjacent part under a cylinder cap 44 becomes invisible. The sock absorber 20 leaks out a very small quantity of hydraulic fluid even if its structure is normal, and is stained in the wheel side adjacent part, but is improved in the outward appearance by hiding the stain of the wheel side adjacent part by its very small quantity of hydraulic fluid. The usable shock absorber 20 is restrained from being unnecessarily replaced when a worker and a driver excessively react to the stain. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid resistance type shock absorber.

A fluid resistance type shock absorber generally includes a cylinder filled with oil as a working fluid, a piston disposed in a reciprocating manner in the cylinder, and a piston rod to which the piston is attached. Yes. When the piston is reciprocated in the cylinder, the approaching / separating speed between the vehicle body and the wheel is reduced by the flow resistance when the oil passes through a resistance applying portion such as a throttle and an on-off valve provided in the piston. A damping force is generated. The following Patent Documents 1 to 3 describe examples of shock absorbers, and the following Patent Documents 4 and 5 describe hydraulic actuators having a structure similar to a shock absorber.
Japanese Patent Laid-Open No. 8-200334 JP 2006-220162 A Utility Model Registration No. 2588470 Japanese Utility Model Publication No. 2-71209 Japanese Utility Model Publication No. 1-250635

  Patent Documents 2 and 3 describe a seal member disposed between a cylinder and a piston rod so that oil does not leak. However, with the aging of the seal member, the ability to wipe off oil adhering to the piston rod gradually decreases, and a small amount of oil may leak from between the seal member and the piston rod. And when the leaked oil spreads from the lower side of the cylinder cap to the cylinder outer peripheral surface, there is a problem that the outer peripheral surface becomes dirty and looks bad.

Patent Document 1 describes a dust cover that covers the upper part of a cylinder. For example, during inspection work, tire replacement, brake maintenance, repair, etc., when the vehicle body is jacked up and the wheels are separated from the vehicle body, Since the cylinder is moved relative to the lower side of the dust cover and exposed to the outside, there is a problem that dirt is visually recognized by an operator and a driver. Note that Patent Documents 4 and 5 describe a dust cover that covers a cylinder of a hydraulic actuator. However, the dust covers described in Patent Documents 4 and 5 deal with liquid leakage from the connecting portion of the oil supply / discharge pipe and liquid leakage that is intentionally allowed to reduce the sliding resistance of the seal. Is. Therefore, there is a problem that it is too costly to cope with a small amount of liquid leakage as described above.
The above problem is an example of a problem that can be an obstacle to improving the practicality of a conventional shock absorber, and there is room for improvement from various viewpoints in the shock absorber. In other words, by improving the conventional shock absorber, it is possible to make the shock absorber more practical, such as preventing the appearance of the shock absorber from deteriorating while suppressing an increase in cost. This invention is made | formed in view of such a situation, and it was made | formed as a subject to improve the practicality of a shock absorber.

  In order to solve the above problems, a shock absorber according to the present invention includes a cylinder having a seal that slides against the piston rod extending from one end portion to prevent leakage of hydraulic fluid contained therein, and the one end portion of the cylinder. A cap that forms a liquid discharge passage that continues from the seal to the outer peripheral surface of the one end in cooperation with one end thereof, and a portion of the cylinder adjacent to the cap on the other end side has a radial gap. And a cylindrical covering body that is spaced apart.

  According to the present invention, it is possible to prevent the appearance of the shock absorber from being deteriorated by concealing dirt due to the hydraulic fluid that has leaked in a normal operating state by the covering body, and thus unnecessary replacement of the shock absorber. Can be suppressed. That is, a more practical shock absorber can be obtained. Various aspects of the shock absorber according to the present invention and their actions and effects will be described in detail in the following [Aspect of the Invention] section.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is for the purpose of facilitating the understanding of the claimable invention, and is not intended to limit the combinations of the constituent elements constituting the claimable invention to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In each of the following paragraphs, (1) is in claim 1, (2) is in claim 2, (3) is in claim 3, and (5) and (6) are combined. These correspond to claim 4 respectively.

(1) a piston rod connected to a part of the vehicle body;
A cylinder that slides against the piston rod extending from one end and prevents leakage of hydraulic fluid contained therein, and a cylinder whose other end is connected to the wheel holding portion;
A cap that covers the one end portion of the cylinder in a state of penetrating the piston rod and forms a liquid discharge passage continuous with the one end portion from the seal to the outer peripheral surface of the one end portion;
A shock absorber, comprising: a cylindrical covering that covers a portion of the cylinder adjacent to the cap on the other end side with a gap in a radial direction therebetween.
The shock absorber according to this section, for example, contains hydraulic fluid in a cylinder and generates a fluid flow resistance force by reciprocating a piston attached to the base end of a piston rod in the cylinder. can do. In order to prevent the hydraulic fluid inside the cylinder from leaking out, a seal (for example, a lip seal) that is in fluid-tight contact with the piston rod is provided. A cap is fixed to the vehicle body side of the seal.For example, when the suspension device bounces greatly, that is, when the wheel and the vehicle body greatly approach, a bounce stopper and cap attached to the tip end side of the piston rod , The impact at the time of bouncing is alleviated, and the seal and the end surface on the one end side of the cylinder are protected from contacting the bouncing stopper.
The cap of this section is provided with a liquid discharge passage. For example, when rainwater or the like enters the cap through the piston rod, it is discharged through the liquid discharge passage. Yes. Further, as described above, a small amount of hydraulic fluid leaking from between the piston rod and the seal can spread to the outer peripheral portion of one end of the cylinder through the liquid discharge passage.
Conventionally, the outer peripheral surface of the cylinder located below the cap has been exposed to the outside and is often easily visible. For this reason, if the hydraulic fluid adheres to the outer periphery of the cylinder, the cylinder may become dirty (for example, bleeding of the hydraulic fluid), the appearance may be deteriorated, and unnecessary shock absorber replacement may be performed. It was. Further, since the hydraulic fluid mainly spreads from the one end side to the other end side of the cylinder along the outer peripheral surface, the portion near the cap tends to be relatively dirty. Therefore, the “other end side adjacent portion” that is a portion adjacent to the cap on the other end side of the cylinder tends to be particularly easily contaminated among the portions visible from the outside when there is no covering.
On the other hand, the shock absorber of this section can prevent the appearance of the shock absorber from deteriorating by hiding the dirt on the other side adjacent to the other end side due to the hydraulic fluid leaked by the cover, which is unnecessary. It is possible to prevent the shock absorber from being replaced. That is, a more practical suspension device can be obtained.
Note that the axial length of the portion covered with the covering is effective to prevent the appearance of the shock absorber from deteriorating, for example, even if the length is relatively short (for example, 1 cm), but there is a margin. Desirably, the dimensions (for example, dimensions equal to or larger than the diameter of the cylinder). Further, it is not always necessary that the cap and the cover are in close contact with each other, and there may be a gap so that dirt is not noticeable. In addition, a small gap (for example, 0.5 mm) is sufficient between the cover and the cylinder, but it is desirable that the gap be, for example, about 0.5 mm to 5 mm in consideration of processing accuracy and component size. Moreover, the said clearance gap may be ensured large, for example with 5 mm or more (for example, 10 mm).
For example, the covering can cover the other end side adjacent portion over the entire circumference, but this is not an indispensable matter and can be discontinuous in the circumferential direction or the axial direction. For example, the adjacent portion on the other end side is mainly visible from the outside in the width direction of the vehicle body (hereinafter, abbreviated as “outside” unless otherwise required), and is rarely seen from the center side of the vehicle body. The cross-sectional shape may be C-shaped so as not to cover the vehicle body center side of the adjacent portion on the other end side. In addition, for example, even if it is a part that covers the outside of the other end of the cylinder, a hole or a notch may be provided or a bowl-like shape may be provided as long as the dirt on the cylinder can be made inconspicuous. Good.
(2) The cap is
The piston rod has a through-hole through which the piston rod extends and covers the end surface on the one end side of the cylinder, and at least part of the end surface continues from the seal to the outer periphery of the one end portion. An end surface covering portion that is separated from the end surface covering portion to form the first liquid discharge passage portion;
The cylinder hangs down from the outer peripheral portion of the end surface covering portion toward the other end portion of the cylinder, and is fitted to the outer periphery of the one end portion of the cylinder, and at least a part of the outer peripheral portion of the end surface covering portion. The second liquid that is continuously spaced from the end surface to the lower end of the cylinder and spaced from the outer peripheral surface of the one end of the cylinder, and forms the liquid discharge passage in cooperation with the first liquid discharge passage portion. The shock absorber according to item (1), including a peripheral wall portion forming a discharge passage portion.
The cap of this section is provided with a peripheral wall portion fitted to one end portion of the cylinder, and the end surface covering portion can be fixed to one end portion of the cylinder relatively easily.
In this aspect, the liquid discharge passage includes a gap between the end surface of the cylinder and the end surface covering portion (first liquid discharge passage portion), and a gap between the outer peripheral surface of the cylinder and the peripheral wall portion (second liquid discharge passage portion). Is formed by communicating. In this embodiment, the working fluid leaked from between the piston rod and the seal passes through the liquid discharge passage and adheres to the outer peripheral surface of the other end portion of the cylinder, and further spreads to the other end portion side from the peripheral wall portion. It becomes. Therefore, it can be said that the portion of the cylinder adjacent to the peripheral wall portion on the other end side is easily contaminated, and it is highly necessary to cover the other end side adjacent portion of the cylinder with the covering.
(3) The covering body extends upward from the other end side adjacent portion covering portion that covers a portion of the cylinder adjacent to the cap on the other end side, and the other end side adjacent portion covering portion. The shock absorber according to item (2), including a peripheral wall fitting portion fitted on an outer periphery of the peripheral wall portion.
The aspect of this term is an aspect in which the upper part (the end part on one end part side) of the covering body is fitted and fixed to the outer periphery of the peripheral wall part. By covering at least the lower end portion of the peripheral wall portion with the upper portion of the covering body, the adjacent portion on the other end side (part that is particularly easily contaminated as described above) can be more reliably covered. In addition, the possibility that the hydraulic fluid adheres to the outside of the covering can be reduced. Furthermore, by fixing the upper end portion of the covering body, the rigidity of the other-end-side adjacent portion covering portion can be made lower than when not fixing.
Although different from the aspect of this section, a separation peripheral wall portion spaced from the outer peripheral portion of the cylinder is provided at the lower end of the peripheral wall portion, and an inner peripheral side fitting portion that is fitted inside the separation peripheral wall portion is provided at the upper end of the covering. Thus, the upper end portion of the covering body can be fixed by fitting the inner peripheral side fitting portion into the separated peripheral wall portion. In this aspect, the arrangement space can be slightly reduced as compared with the aspect including the peripheral wall fitting portion. In terms of preventing the working fluid from adhering to the outside of the covering, it is advantageous to cover the outer periphery of the peripheral wall portion with the upper portion of the covering.
(4) The shock absorber according to any one of (1) to (3), wherein the covering is fixed to the cylinder at a lower portion thereof.
According to the aspect of this section, the strength of the covering itself can be lowered by directly or indirectly fixing the lower portion of the covering to the cylinder as compared with the case where it is not fixed. In addition, the aspect of this term can be made into the aspect in which a coating | cover has a "lower fixing | fixed part" in the lower part of itself.
(5) The shock absorber includes a spring support member fixed to the cylinder and supporting a lower end portion of a coil spring on the other end side of the cap. The listed shock absorber.
In the aspect of this section, for example, the covering body may cover at least a lower part of the cap of the cylinder and a part above (one end part side) above the spring support member. Further, when the aspect of this section is dependent on the above section (4), the lower part of the covering can be fixed to the cylinder by supporting it with a spring support member.
(6) The covering body is disposed between the spring support member and the coil spring, and is integrally formed with a vibration transmission relaxation body that relaxes vibration transmission between the coil spring and the spring support member. The shock absorber according to item (5).
In some cases, a vibration transmission relaxation body (or vibration transmission relaxation sheet) such as an insulator is disposed between the spring support member and the coil spring. In such a case, by forming the covering body integrally with the vibration transmission relaxation body, it is possible to suppress an increase in the number of parts when the covering body is provided.

  Embodiments of the claimable invention will be described below with reference to the drawings. In addition to the following examples, the claimable invention can be practiced in various modifications based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. .

  FIG. 1 is a front view of a suspension device 10 including a shock absorber according to an embodiment of the claimable invention. In this embodiment, the suspension device 10 includes a shock absorber 20 (hereinafter abbreviated as “absorber” unless otherwise required), a compression coil spring 22 (hereinafter abbreviated as “spring” unless otherwise specified), an upper A support 24, a dust cover 26, a bound stopper 28, and an under cover 30 are provided.

  The absorber 20 includes a cylinder 40 filled with hydraulic fluid as hydraulic fluid, and a piston rod 42 (hereinafter abbreviated as “rod” unless otherwise required) that is held axially movable by the cylinder 40. Including. A cylinder cap 44 (hereinafter abbreviated as “cap” unless otherwise required) is put on the upper end portion of the cylinder 40 (referred to as the rod side end portion). A piston (not shown) is disposed in the cylinder 40 so as to be able to reciprocate, and is attached to the end of the rod 42. The piston is provided with resistance applying portions such as a throttle and an on-off valve, and when the piston moves in the cylinder 40, a damping force corresponding to the moving speed of the piston is generated by the flow resistance through which the hydraulic oil passes through the throttle. appear.

  The upper support 24 is also referred to as a mount insulator, and is a mechanism (upper connection mechanism) that elastically connects a part 46 of the vehicle body and the upper end of the suspension device 10. The upper support 24 includes an outer cylinder member 50 fixed to a part 46 of the vehicle body, an inner cylinder member 52 that holds the tip of the rod 42, and a mount rubber 54 that elastically connects them. That is, the tip of the rod 42 is elastically connected to a part 46 of the vehicle body via the upper support 24. On the other hand, the lower end portion of the cylinder 40 is connected to a wheel holding member that holds a wheel (not shown). That is, the absorber 20 generates a resistance force corresponding to the approaching / separating speed between the part 46 of the vehicle body and the wheel, that is, a damping force.

Further, a spring upper support plate 60 (abbreviated as “upper support plate” unless otherwise required) that supports the upper end portion of the spring 22 is fixed to the rod 42 below the upper support 24. The upper support plate 60 has a generally disc shape, and is fixed in a state where the rod 42 is passed through a hole provided in a slightly eccentric portion. At the peripheral edge of the upper support plate 60, the upper end of the spring 22 is supported from above.
On the other hand, a spring lower support plate 62 (an example of a spring support member) that supports the lower end portion of the spring 22 is fixed to the outer peripheral portion of the cylinder 40. The lower spring support plate 62 (abbreviated as “lower support plate” unless otherwise required) is generally bowl-shaped, and is fixed to the outer peripheral portion of the cylinder 40 at an annular portion 64 provided at an eccentric portion. ing. In addition, the lower end portion of the spring 22 is supported from below at the peripheral edge portion of the hook-like portion 66 that extends obliquely upward on the outer peripheral side from the annular portion 64.
A part of the annular portion 64 is separated from the cylinder 40, and a drain hole 68 for draining rainwater or the like is formed. Further, in the present embodiment, the spring 22 is disposed in an inclined state at a position eccentric with respect to the rod 42, so that a force perpendicular to the axial direction is hardly applied to the absorber 20.

  A bound stopper 28 is fixed to the lower surface of the upper support plate 60 with the rod 42 penetrating therethrough. The bound stopper 28 extends downward in the axial direction, and the outer diameter of the upper portion is increased. That is, the greater the bounce amount (the amount of approach between a part of the vehicle body and the wheel), the greater the repulsive force.

  The dust cover 26 includes a cylindrical portion 70 that covers the piston rod 42, the bound stopper 28, and the upper portion of the cylinder 40, and an annular upper insulator portion 72. Most of the cylindrical part 70 is formed in a bellows shape, and is adapted to expand and contract in accordance with the bound amount. The upper insulator portion 72 is sandwiched and fixed between the upper support plate 60 and the spring 22 at the peripheral portion thereof, and extends downward from the peripheral portion of the upper support plate 60 and is connected to the upper end of the tubular portion 70. ing. Further, the vibration transmitted between the upper support plate 60 and the spring 22 is mitigated by the upper insulator portion 72.

An under cover 30 made of synthetic rubber is disposed on the upper side of the bowl-shaped portion 66 of the lower support plate 62. The under cover 30 is a cylinder cover portion 80 (which is an example of a cover) that covers the outer periphery of the cylinder 40 in a cylindrical shape, and a lower insulator portion 82 (which is an example of a vibration transmission moderating body) that is generally disk-shaped. ).
At the upper end portion of the cylinder cover portion 80, an annular convex portion 90 that protrudes toward the inner peripheral side over the entire circumference is provided. The upper end portion of the cylinder cover portion 80 is fixed by the annular convex portion 90 being fitted into and engaged with an outer peripheral groove provided on an outer peripheral portion of the cap 44 described later.
The lower insulator portion 82 is sandwiched and fixed between the lower support plate 62 and the spring 22 at the peripheral portion thereof, and alleviates vibration transmitted between the lower support plate 62 and the spring 22. The lower insulator portion 82 is connected to the lower end portion of the cylinder cover portion 80 at the inner peripheral portion thereof, and indirectly fixes the cylinder cover portion 80 to the cylinder 40 at the lower portion thereof. That is, the cylinder cover part 80 of the present embodiment is a mode in which the cylinder cover part 80 is fixed to the cylinder 40 at the lower part of the cylinder cover part 80 itself.
Further, the under cover 30 is provided with a drain hole 92 for draining rain water or the like at a portion where the lower end portion of the cylinder cover portion 80 and the inner peripheral portion of the lower insulator portion 82 are connected.

In FIG. 2, the front cross section of the upper end part of the cylinder 40 is shown. The cylinder 40 includes an outer tube 100 having a generally cylindrical shape with a bottom, and a cylindrical inner tube 102 disposed on the inner periphery of the outer tube 100, and a reservoir chamber 104 is formed therebetween. ing.
A rod guide 106 that guides the rod 42 in the axial direction is provided on the inner periphery of the upper end portion of the cylinder 40. The rod guide 106 is fitted to the inner side of the outer tube 100 at the upper part and the inner side of the inner tube 102 at the lower part, and is supported from below by the upper end part of the inner tube 102. A bushing 108 is provided on the inner peripheral portion of the rod guide 106 so that the rod guide 106 can be smoothly moved relative to the rod 42.

A flat plate-shaped seal support ring 110 is placed on the upper portion of the rod guide 106, and the seal support ring 110 and the rod guide 106 are connected to the outer tube 100 and the inner tube 102 by the end of the outer tube 100 crimped inside. It is fixed to.
A lip seal 112 is disposed on the inner periphery of the seal support ring 110. Specifically, the lip seal 112 is fixed by fitting the inner peripheral portion of the seal support ring 110 into the fitting groove formed on the outer peripheral portion of the lip seal 112. The lip seal 112 has a dust lip 114 extending to the cap 44 side and a main lip 116 extending to the rod guide 106 side, and ring-shaped springs are attached to the outer peripheral portions of the lip seal 112, respectively, and the rod 42 with an appropriate pressure. It is made to adhere to.
The dust lip 114 prevents dust from entering the cylinder 40. Further, when the main lip 116 is in sliding contact with the outer peripheral surface of the rod 42 at the inner peripheral portion, the hydraulic oil adhering to the rod 42 is wiped off, so that the hydraulic oil inside the cylinder 40 hardly leaks to the outside. . However, it is difficult to prevent the hydraulic oil from completely leaking out due to the structure that prevents the wear of the lip seal 112 by forming a small amount of oil film. Oil may leak.
On the other hand, an annular outer seal 120 is fixed to the lower surface of the outer peripheral portion of the seal support ring 110. The outer seal 120 is brought into liquid-tight contact with the inner peripheral surface of the outer tube 100, whereby the gap between the seal support ring 110 and the outer tube 100 is closed.
In this embodiment, the seal support ring 110, the lip seal 112, and the outer seal 120 constitute an opening closing portion 122 that liquid-tightly closes the opening on the rod 42 side of the cylinder 40. Further, the lip seal 112 constitutes the “seal that prevents the leakage of the hydraulic fluid contained in the sliding contact with the piston rod”.

The cylinder cap 44 (abbreviated as “cap” unless otherwise required) will be described.
The cap 44 covers the rod-side end surface of the cylinder 40. For example, when the suspension device 10 has a large stroke in the bound direction, the cap 44 abuts against the bound stopper 28 disposed above, and the lip seal 112 or the like is placed. Protect. The cap 44 has a hole 128 through which the rod 42 passes, and a disk-shaped top plate portion 130 (an example of an end surface covering portion) facing the rod 42 side end surface of the cylinder 40, and the top plate portion 130. A cylindrical wall portion 132 (which is an example of a peripheral wall portion) provided so as to hang from the outer peripheral end toward the lower end portion side of the cylinder 40, and a reinforcing plate portion 134 fixed to the upper side of the top plate portion 130. Have. Note that the reinforcing plate portion 134 can be omitted when the strength of the top plate portion 130 is relatively large, or when the force applied from the bound stopper 28 to the cap 44 is relatively small.

FIG. 3 shows a plan view of the top plate portion 130 (the reinforcing plate portion 134 is not shown). The cross section of the cap 44 in FIG. 2 is the BB cross section of FIG.
A plurality of recesses 136 (four in the figure) that are separated from each other in the circumferential direction are provided on the outer peripheral portion of the top plate portion 130. Due to the presence of the concave portion 136, the top plate portion 130 is located at a position where the retreating wall portion 138 is retreated toward the cylindrical wall portion 132 with respect to the other portions, and the retreating wall portion 138 is further away from the cylinder 40. A separation wall 140 is formed. The cap 44 placed on the rod side end of the cylinder 40 is fixed in a state where it abuts against the end surface of the outer tube 100 at the receding wall portion 138, and the separation wall portion 140 and the rod side end surface of the cylinder 40 (specifically, , The opening closing portion 122 and the end portion of the outer tube 100) are kept apart from each other, and a gap 144 is formed between them. The gap 144 communicates from the lip seal 112 to the outer peripheral end of the top plate portion 130 so that rainwater or the like that has entered the cap 44 can be discharged.

FIG. 4 shows an AA cross section (see FIG. 1) of the cylindrical wall portion 132 and the outer tube 100.
The cylindrical wall portion 132 has an inner diameter that is larger than the outer diameter of the outer tube 100 by a set amount, and most of the cylindrical wall portion 132 is separated from the outer tube 100 so as to form a gap. A plurality of convex portions 150 (four in the drawing) are provided at the lower portion of the cylindrical wall portion 132 so that the wall portion protrudes toward the inner peripheral side at locations separated from each other in the circumferential direction. The cap 44 is fixed to the outer tube 100 by pressing the plurality of convex portions 150 into the outer tube 100. And the part other than the convex part 150 of the cylindrical wall part 132 is made into the state spaced apart from the outer tube 100, and the clearance gap 152 following the said clearance gap 144 is formed. The gap 152 communicates from the outer peripheral end of the top plate portion 130 to the lower end of the cylindrical wall portion 132, and the gap 144 communicates with the outside (below the cap 44). As a result, rainwater or the like accumulated in the cap 44 can be discharged from the gap 152 between the cylindrical wall portion 132 and the outer tube 100.
Further, an outer peripheral groove 156 is formed on the outer peripheral portion of the cylindrical wall portion 132 as an engaged portion into which the annular convex portion 90 at the upper end of the cylinder cover 80 is fitted. That is, the annular convex portion 90 and the outer peripheral groove 156 form an engaging portion and an engaged portion for engaging the cylinder cover portion 80 with the cylindrical wall portion 132.
In the present embodiment, the gap 144 constitutes the “first liquid discharge passage portion”, and the gap 152 constitutes the “second liquid discharge passage portion”.

With the configuration described above, in the shock absorber 20, a small amount of hydraulic oil leaked from between the lip seal 112 and the rod 42 spreads through the gaps 144 and 152, and the outer peripheral surface of the rod side end of the cylinder 40. May adhere to the surface and cause dirt (bleeding of hydraulic oil). Here, assuming that the cylinder cover portion 80 is not provided, such dirt is visible, and it is mistakenly recognized that the shock absorber 20 is abnormal or has expired during maintenance of a brake or the like, and can still be used. In spite of this, there is a risk of being exchanged. In addition, the dust cover 26 covers the dirt on the rod side end of the cylinder 40 to some extent, but when the vehicle body is jacked up, the cylinder 40 is lowered relative to the part 46 of the vehicle body together with the wheels. The upper part of 40 will be exposed. Thus, if dirt is seen during maintenance or tire replacement, unnecessary shock absorber 20 may be replaced.
Further, since the hydraulic oil spreads downward from the portion covered by the cap 44 of the cylinder 40, the portion close to the cap 44 tends to become dirty. In addition, since the part covered with the cap 44 of the cylinder 40 cannot be seen even if it is dirty, it is not a problem. Therefore, when the cylinder cover portion 80 is not provided, it can be said that the portion immediately below the cylindrical wall portion 132 of the cap 44 is a portion that can be visually recognized and particularly easily contaminated. That is, the wheel side adjacent portion (an example of the other end side adjacent portion) adjacent to the cylindrical wall portion 132 on the wheel side end portion side of the cylinder 40 can be visually recognized when the cylinder cover portion 80 is not provided. It is a particularly dirty part. In addition, in this figure, the oil stain | pollution | contamination 160 which is the stain | pollution | contamination produced by the hydraulic oil adhering to a wheel side adjacent part was shown typically.

As shown in FIG. 5, the shock absorber 20 is provided with an under cover 30 against the above-described dirt, and the wheel side adjacent portion of the cylinder 40 is covered by the cylinder cover portion 80 thereof. Therefore, even if the vehicle body is jacked up, the oil stain 160 (see FIG. 1) at the rod side end of the cylinder 40 is not visually recognized, and deterioration of appearance is prevented. As a result, it is prevented that an operator and a driver | operator react excessively with the oil stain | pollution | contamination 160 by the leakage of the hydraulic oil in a normal range, and it is difficult to perform unnecessary replacement | exchange of the shock absorber 20. FIG. That is, the shock absorber 20 is highly practical and can suppress an increase in the maintenance cost of the vehicle.
In this embodiment, the cylinder cover portion 80 covers the upper portion of the lower insulator portion 82 below the cap 44 in the cylinder 40, but for the purpose of hiding the oil stain 160. You can think that doesn't have to be that long. In some cases, for example, the length may be about half as in a modification described later. However, the cylinder cover portion 80 extends from the lower portion of the cap 44 to the lower insulator portion 82, so that it can be connected to the inner peripheral portion of the lower insulator portion 82, and the lower portion of the cylinder cover portion 80 is connected to the lower insulator portion. It is fixed to the cylinder 40 via the part 82.

  In the present embodiment, the portion below the cap 44 of the cylinder cover portion 80 constitutes the “other end side adjacent portion covering portion”. The portion of the cap 44 that covers the cylindrical wall portion 132 constitutes the “circumferential wall fitting portion”. Since the lower portion of the cylinder cover portion 80 is indirectly fixed to the cylinder 40 via the lower insulator portion 82, the lower insulator portion 82 constitutes the “lower fixed portion”.

In the above embodiment, the suspension device 10 is configured such that the cylindrical wall portion 132 of the cap 44 is covered by the cylinder cover portion 80. However, as shown in FIG. The suspension device 220 including the cover 210 can be obtained. In this aspect, a plurality of ridges (ribs) 230 that are gap forming bodies that increase the rigidity of the cylinder cover part 200 and form an appropriate gap between the inner peripheral part of the cylinder cover part 200 and the cylinder 40 are provided. ing.
FIG. 7 shows a CC cross section. In addition, the cross section of the cylinder cover part 200 in FIG. 6 is DD cross section of FIG.
The plurality of ridges 230 are arranged on the inner peripheral part of the cylinder cover part 200 so as to be spaced apart from each other in the circumferential direction, and extend in the axial direction. In the present embodiment, the number of ridges 230 is four, and is arranged at a position overlapping the projection 150 in the circumferential direction so as to pass between two adjacent gaps 152. The gap forming body is not limited to the ridge, and may be, for example, a convex portion having a hemispherical shape, a square shape, or the like protruding from the inner peripheral portion of the cylinder cover portion 200 toward the central axis.

In the above embodiment, the cylinder cover portion 80 is the suspension device 10 connected to the lower insulator portion 82. However, as shown in FIG. 8, the cylinder cover 300 is separated from the lower insulator 310 as a separate member. The suspension device 320 can be obtained. Also by such a cylinder cover 300, the wheel side adjacent portion can be covered and the dirt 160 of the cylinder 40 can be hidden. In this case, a plurality of ridges (ribs) 330 can be provided on the inner periphery of the portion covering the cylinder cover 300. The ridge 330 has a cross-sectional shape similar to that of the ridge 230 (see FIG. 7). The plurality of ridges 330 are provided on the inner peripheral side of the lower end portion of the cylinder cover 300 and constitute the “lower fixed portion”.
The suspension device 220 and the suspension device 320 have the same configuration as the suspension device 10 except for the undercover.

By the way, when the leakage of the hydraulic oil is excessive, that is, when the lip seal 112 or the piston rod 42 is damaged or when the service life of the shock absorber 320 has passed, the range of normal oil contamination 160 of the cylinder 40 is reached. The hydraulic oil will spread further downward. On the other hand, the cylinder cover 300 has a length in the axial direction such that oil contamination due to excessive leakage of hydraulic oil can be seen.
In this figure, the area covered by the cylinder cover 300 in the outer peripheral surface of the cylinder 40 is a permissible area 350 that allows the oil dirt 160, and the oil dirt 160 due to leakage of hydraulic oil within the normal range is allowed. It falls within the region 350 and is not visible from the outside. On the other hand, oil contamination due to excessive leakage of hydraulic oil spreads below the permissible region 350, so that it can be visually recognized from the outside, and it can be easily determined whether or not the shock absorber 320 is abnormal.
In other words, in this suspension device 320, by covering the allowable area 350 with the cylinder cover 300, the oil stain 160 due to the leakage of hydraulic oil within the normal range is hidden, while the area below the allowable area 350 is not covered. Therefore, the oil stain spreading below the permissible region 350 is made visible due to excessive leakage of hydraulic oil.

In the suspension device 10 of FIG. 1, as shown in FIG. 9, the operation within the normal range can be achieved by providing the cylinder cover 80 with an inspection window 400 that makes it possible to visually recognize dirt due to excessive leakage of hydraulic oil. While hiding dirt caused by oil leakage, dirt caused by excessive hydraulic oil leakage can be made visible. In this aspect, the above-described allowable area 350 is an area above the upper end of the inspection window 400 in the outer peripheral surface of the cylinder 40.
The inspection window 400 can be easily inspected, for example, if it is provided in the outer portion of the cylinder cover 80 in the width direction of the vehicle body. However, from the viewpoint of improving the appearance, for example, the cylinder cover 80 can be provided on the front side or the rear side of the vehicle body.
Further, the ridge 230 or the ridge 330 can be provided on the cylinder cover portion 80 of the suspension device 10.

It is a front view which shows the suspension apparatus provided with the shock absorber which is an Example of claimable invention. It is front sectional drawing which shows the one end part of the cylinder of the said shock absorber. It is a top view which shows the cap of the said shock absorber. It is a plane sectional view showing the above-mentioned cap. It is a front view which shows a mode that the said cylinder was covered. It is a front view which shows the suspension apparatus of an Example different from the above. It is sectional drawing of the cylinder cap of the said suspension apparatus. It is a front view which shows the suspension apparatus of another Example from the above. It is a front view which shows what the inspection window was provided in the suspension apparatus of the first Example.

Explanation of symbols

  10: Suspension device 20: Shock absorber 22: Compression coil spring 26: Dust cover 28: Bound stopper 30: Under cover 40: Cylinder 42: Piston rod 44: Cylinder cap (cap) 46: Part of the vehicle body 62: Spring lower support Plate (spring support member) 80: Cylinder cover part (covering body) 82: Lower insulator part (vibration transmission relaxation body) 90: Annular convex part 100: Outer tube 106: Rod guide 110: Seal support ring 112: Lip seal ( 122: Opening closing part 130: Top plate part (end face covering part) 132: Cylindrical wall part (peripheral wall part) 136: Recessed part 138: Retreating wall part 140: Separating wall part 144: Gap (first liquid discharge passage) 150: Convex part 152: Gap (second liquid discharge passage) 156: Peripheral groove 160: Wheel side adjacent part (other end side adjacent part) 200: Cylinder cover part (cover) 210: Under cover 220: Suspension device 230: Convex Article 300: Cylinder cover (covered body) 310: Lower insulator 320: Suspension device 330: Projection strip 400: Inspection window

Claims (4)

A piston rod connected to a part of the vehicle body;
A cylinder that slides against the piston rod extending from one end and prevents leakage of hydraulic fluid contained therein, and a cylinder whose other end is connected to the wheel holding portion;
A cap that covers the one end portion of the cylinder in a state of penetrating the piston rod and forms a liquid discharge passage continuous with the one end portion from the seal to the outer peripheral surface of the one end portion;
A shock absorber, comprising: a cylindrical covering that covers a portion of the cylinder adjacent to the cap on the other end side with a gap in a radial direction therebetween. The cap is
The piston rod has a through-hole through which the piston rod extends and covers the end surface on the one end side of the cylinder, and at least part of the end surface continues from the seal to the outer periphery of the one end portion. An end surface covering portion that is separated from the end surface covering portion to form the first liquid discharge passage portion;
The cylinder hangs down from the outer peripheral portion of the end surface covering portion toward the other end portion of the cylinder, and is fitted to the outer periphery of the one end portion of the cylinder, and at least a part of the outer peripheral portion of the end surface covering portion. The second liquid that is continuously spaced from the end surface to the lower end of the cylinder and spaced from the outer peripheral surface of the one end of the cylinder, and forms the liquid discharge passage in cooperation with the first liquid discharge passage portion. The shock absorber according to claim 1, further comprising a peripheral wall portion forming a discharge passage portion.   The covering body is extended upward from the other end side adjacent portion covering portion that covers a portion of the cylinder adjacent to the cap on the other end portion side, and the other end side adjacent portion covering portion. The shock absorber according to claim 2, including a peripheral wall fitting portion fitted on the outer periphery. The shock absorber includes a spring support member fixed to the cylinder and supporting a lower end portion of a coil spring on the other end side than the cap;
The said covering body is arrange | positioned between the said spring support member and the said coil spring, and is formed integrally with the vibration transmission mitigation body which relieve | moderates the vibration transmission between the coil spring and the said spring support member. Item 4. The shock absorber according to any one of Items 1 to 3.

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