JP5444159B2 - Fluid pressure buffer - Google Patents

Description

  The present invention relates to a fluid pressure shock absorber, and more particularly to weight reduction of a fluid pressure shock absorber in which a head member is coupled to a coupling means coupled to an inner tube and a cylinder is sandwiched between the head member and a bottom member.

  Various proposals have been made for fluid pressure shock absorbers so far. For example, the fluid pressure shock absorber is used as a suspension device such as a front fork or a rear cushion unit that suspends a wheel of a two-wheeled vehicle and attenuates road surface vibration input to the wheel. The

  Patent Document 1 discloses a configuration of a conventional front fork. The front fork includes a fork body including an outer tube and an inner tube that is slidably inserted into the outer tube, and is inverted. Set to type.

  The fork main body is provided with a cap member for sealing the upper and lower openings and a bottom member, and the fork main body accommodates an upright damper that generates a predetermined damping force therein. A reservoir chamber for storing the working fluid is formed between the damper and the damper.

  The damper includes a cylinder that stands up at the axial center of the inner tube and accommodates a working fluid, a rod that is fixed to the outer tube and protrudes and retracts into the cylinder, and is held at the tip of the rod to move inside the cylinder. A piston partitioning into two working chambers.

  As disclosed in FIGS. 3 and 4 of Patent Document 1, a head member and a base member are respectively screwed into the head portion and the bottom portion of the cylinder.

  By the way, the bottom member that seals the lower opening of the fork main body is formed in a cylindrical shape, and an opening-side large opening that forms a large-diameter columnar space on the fork main body side, and the cylindrical space A rear-side small opening that forms a small-diameter cylindrical space extending coaxially.

  And by providing the said structure, the bottom part of an inner tube is screwed together in the said opening side large opening inner periphery, the said base member is inserted in the said back side small opening part, and the said base member outer periphery and a back side small opening The space between the inner periphery is sealed with a seal member.

  Next, the cylinder can be fixed to the bottom member by screwing the bottom portion of the cylinder into the base member.

  In the front fork of Patent Document 1, it is necessary to thread the opening on the head side and the bottom side of the cylinder. For this threading, at least the thickness of the opening is increased and threading is performed. It is necessary to prevent the mechanical strength from being lowered, which obstructs the weight reduction of the front fork, and requires labor for processing.

  Therefore, the applicant has created the following front fork as a fluid pressure shock absorber in order to reduce the weight and improve the workability without the need for threading the cylinder.

  As shown in FIG. 6, this front fork has the same basic structure as the front fork of Patent Document 1, and the bottom member 20 is formed in a bottomed cylindrical shape, and has a large opening side opening 20a, A small side opening 20b and a step 20c are provided.

  A guide washer W1 and a washer W2 are sequentially stacked on the stepped portion 20c. The guide washer W1 is formed in an annular shape, and an inner peripheral portion thereof is curved downward in FIG. 6, and the washer W2 is formed in an annular shape. It is formed in a flat plate shape.

  Then, the bottom portion (the lower side in the figure) of the inner tube 2 is screwed into the inner periphery of the opening side large opening portion 20a, and the guide washer W1 and the washer W2 are placed between the step portion 20c and the bottom end of the inner tube 2. Hold it.

  Next, the bottom portion (the lower side in the figure) of the cylinder 31 is inserted into the back side small opening 20b, and the head member 30 is screwed into the coupling means J coupled to the inner tube 2, so that the head member 30 and the bottom member 20 holds the cylinder 31.

  By providing the above configuration, the conventional front fork can receive the surface pressure of the inner tube 2 with the washer W2, and can be inserted into the back side small opening 20b while aligning the cylinder 31 with the guide washer W1. Become.

JP 2008-69830 A

  In the above-described conventional fluid pressure shock absorber as a front fork, it is useful in that it is possible to reduce the weight of the fluid pressure shock absorber and improve the workability without the need for threading of the cylinder. There is a need for further weight reduction.

  Further, when burrs are generated at the inner peripheral side end or the like of the guide washer W1, there is a risk that the outer peripheral surface of the cylinder 31 may be damaged by the burrs when the cylinder 31 is guided into the rear side small opening 20b. is there.

  Therefore, an object of the present invention is to provide a fluid pressure shock absorber that enables alignment of the cylinder 31 without providing the guide washer W1.

  Means for solving the above problems includes a shock absorber body comprising an outer tube, an inner tube slidably inserted into the outer tube, and a cylindrical space that opens to the shock absorber body side. A bottom member coupled to the outer periphery of the bottom side opening of the shock absorber body, and a damper that is accommodated in the shock absorber body and generates a predetermined damping force, the damper being an axial center of the inner tube A cylinder that stands up in the section and accommodates the working fluid therein, and the bottom portion of the inner tube is coupled to the inner periphery of the bottom member, and then the cylinder is inserted into the inner tube and coupled to the inner tube. A fluid pressure shock absorber that clamps the cylinder between the head member fixed to the coupling means and the bottom member and fixes the cylinder to the bottom member Oite, comprising a partition wall member for aligning the cylinder, the bottom member is to support the cylinder through the partition member.

  According to the present invention, since it is possible to align the cylinder with the partition member, there is no need to attach a conventional guide washer, and there is no possibility of damaging the cylinder with burrs generated in the guide washer.

It is a side view which cuts and shows the left side of the front fork which is a fluid pressure buffer which concerns on one embodiment of this invention. It is a half sectional view which expands and shows the bottom part of the front fork which is a fluid pressure buffer concerning one embodiment of the present invention. FIG. 5 is an enlarged plan view showing a bottom portion of a front fork that is a fluid pressure shock absorber according to an embodiment of the present invention, and showing a modification of the partition member shown in FIG. 2. FIG. 9 is an enlarged view of a bottom portion of a front fork that is a fluid pressure shock absorber according to an embodiment of the present invention, and is a determination plane view showing another modification of the partition wall member shown in FIG. 2. FIG. 6 is an enlarged plan view of a bottom portion of a front fork that is a fluid pressure shock absorber according to an embodiment of the present invention, showing another embodiment of a partition wall member. It is a longitudinal cross-sectional view which shows the front fork which is the conventional fluid pressure buffer partially.

  A fluid pressure shock absorber according to an embodiment of the present invention will be described below with reference to the drawings. The same reference numerals given throughout the several drawings indicate the same or corresponding parts.

  The fluid pressure shock absorber according to the present embodiment is a front fork that suspends a front wheel of a motorcycle and attenuates road surface vibration input to the front wheel due to unevenness of the road surface.

  Although not shown, the front fork is composed of a pair of left and right fork members whose upper end portions are connected by a bridge mechanism, and the lower ends of the fork members are connected to the axles of the front wheels and suspended so as to sandwich the front wheels.

  Further, although not shown, the bridge mechanism has a steering shaft coupled to a handle, and the front mechanism can be steered by operating the handle by including the configuration.

  As shown in FIG. 1, the fork member includes a fork main body that is a shock absorber main body including an outer tube 1 and an inner tube 2 that is slidably inserted into the outer tube 1, and an opening on the fork main body side. A bottom member 20 having a cylindrical space that is coupled to the outer periphery of the bottom side opening of the fork main body, and a damper 3 that is accommodated in the fork main body and generates a predetermined damping force.

  The damper 3 includes a cylinder 31 that stands on the axial center of the inner tube 2 and accommodates a working fluid therein.

  The fork member connects the bottom portion (lower part in FIG. 1) of the inner tube 2 to the inner periphery of the bottom member 20, and inserts the cylinder 31 into the inner tube 2.

  Next, the fork member fixes the cylinder 31 to the bottom member 20 by sandwiching the cylinder 31 between the head member 30 fixed to the coupling means J coupled to the inner tube 2 and the bottom member 20.

  The fork member includes a partition member 4 that defines an air chamber A in the bottom member 20 and aligns the cylinder 31, and the bottom member 20 is interposed between the cylinder 31 and the partition member 4. Support.

  Hereinafter, each component of the front fork will be described in detail.

  The fork main body composed of the outer tube 1 and the inner tube 2 constitutes an inverted front fork in which the outer tube 1 is disposed on the vehicle body side and the inner tube 2 is disposed on the wheel side.

  The fork main body has its upper and lower ends sealed with a cap member 10 and a bottom member 20, respectively, and includes a suspension spring S1 that absorbs road surface vibration and a damper 3 that generates a predetermined damping force. Contain.

  By providing the above configuration, the front fork can attenuate the expansion and contraction movement of the fork main body accompanying the absorption of road surface vibration by the suspension spring S by the damper 3, and can improve the riding comfort of the motorcycle. Become.

  A reservoir chamber R is formed between the fork main body and the damper 3, and the working fluid is stored and gas is sealed upward through the liquid level O of the working fluid to form an air chamber G. Is done.

  The liquid level O is set so that the bed member 30 contacting the upper end of the cylinder 31 in the drawing is immersed in the working fluid stored in the reservoir chamber R even when the fork main body is extended most when the liquid level O is the lowest. Is done.

  The air chamber G expands and contracts with the expansion and contraction of the fork main body, generates a predetermined spring reaction force, and functions as an air spring.

  Although not shown, the internal pressure of the air chamber G can be adjusted by an air valve provided in the cap member 10.

  The damper 3 accommodated in the fork main body is fixed to the cylinder 31 through the cap member 10 and the cylinder 31 that stands up at the axial center portion of the inner tube 2 and accommodates the working fluid. A rod 32 that appears and disappears, and a damping force generating means that generates a predetermined damping force as the rod 32 appears and disappears.

  The cylinder 31 includes a bed member 30 that is screwed into a coupling means J that is fixed to the inner periphery of the inner tube 2 and abuts against the upper end of the cylinder 31 in the figure, and a base member 34 and a partition wall member 4 at the lower end of the cylinder 31 in the figure. It is pinched between the bottom member 20 which contacts via the.

  The cylinder 31 has two working chambers defined by the piston 33 inside the cylinder 31 formed between the head member 30 and the base member 34, that is, an extension side working chamber located on the rod side. P1 and a pressure side working chamber P2 located on the piston side are formed.

  Although not shown, the head member 30 is formed in an annular shape and includes an annular bush on the inner periphery, and is in sliding contact with the outer periphery of the rod 32 to help the rod 32 smoothly move in and out of the cylinder 31.

  The coupling means J includes an annular stopper member 5 in which the head member 30 is screwed to the inner periphery, and a pin member 6 that couples the stopper member 5 to the inner periphery of the inner tube 2.

  The pin member 6 includes a pin 60 passing through an insertion hole (not shown) opened in the stopper member 5 and an insertion hole (not shown) opened in the inner tube 2, And a snap ring 61 urged toward the head.

  By providing the said structure, the said both insertion holes are made to oppose, the pin 60 is inserted from the stopper member 5 side, and the stopper member 5 is fixed according to the position of the insertion hole of the inner tube 2 with the said pin member 6. It becomes possible.

  The configuration of the coupling means J is not limited to the above, and an appropriate configuration is selected as long as the head member 30 is fixed to the inner tube 2 and the cylinder 31 can be sandwiched between the head member 30 and the bottom member 20. Is possible.

  The damping force generating means for generating a predetermined damping force in the damper 3 includes an extension side leaf valve (not shown) that generates a predetermined damping force when the fork body is extended, and a predetermined damping force when the fork body is contracted. A pressure side leaf valve (not shown) for generating

  In this embodiment, the extension side leaf valve is fixed to the piston 33 held at the tip of the rod 32, and the pressure side leaf valve is fixed to the bottom end (lower side in the figure) of the cylinder 31. Mounted on the base member 34.

  Although not shown, the piston 33 is formed with an extension side flow path and a pressure side flow path communicating with the two action chambers P1 and P2, and the pressure side action chamber P2 side which is the outlet side of the extension side flow path. The extension side leaf valve is mounted to be openable and closable.

  On the other hand, a pressure side check valve C1 that allows only movement of the working fluid from the pressure side action chamber P2 to the extension side action chamber P1 is attached to the pressure side flow path so as to be openable and closable. .

  Further, although not shown in the drawing, the base member 34 is formed with an extension-side channel and a pressure-side channel that communicate the pressure-side action chamber P2 and the reservoir chamber R, and this is the outlet side of the pressure-side channel. The pressure side leaf valve is mounted on the reservoir chamber R side so as to be opened and closed.

  On the other hand, the expansion side flow path of the base member 34 is fitted with an expansion side check valve C2 that allows only movement of the working fluid from the reservoir chamber R to the pressure side working chamber on the outlet side pressure side working chamber P2 side. Is done.

  By providing the above structure, resistance is generated when the working fluid moves by pushing open the leaf valves, so the front fork can function as a fluid pressure damper by attenuating the expansion and contraction movement of the fork body. It becomes.

  Then, when the fork main body expands and contracts, the reservoir chamber R can compensate for the excess or deficient working fluid in the cylinder 31 of the rod 32 through the base member 34.

  The configuration of the damping force generating means is not limited to the above, and a known configuration can be adopted as appropriate.

  The cylinder 31 constituting the damper 3 and the inner tube 2 constituting the fork main body are fixed to a bottom member 20 that seals the lower opening of the fork main body in FIG.

  The bottom member 20 is formed in a bottomed cylindrical shape, and is formed coaxially on the opening side large opening 20a that forms a large-diameter columnar space that opens to the fork main body side, and on the back side of the columnar space. And a rear side small opening 20b that forms a small-diameter cylindrical space, and a step portion 20c formed between the opening side large opening 20a and the back side small opening 20b.

  And the partition member 4 is arrange | positioned on the said step part 20c, and the inner tube 2 is screwed together by the said opening side large opening part 20a, Then, the bottom end (lower end in FIG. 1) of the inner tube 2 and The partition member 4 is sandwiched between the stepped portion 20c.

  As shown in FIG. 2, the partition member 4 includes a cylindrical portion 40 whose outer periphery is in close contact with the inner periphery of the inner tube 2, and a ceiling portion 41 that seals the ceiling surface of the cylindrical portion 40. A tapered surface 41 a for aligning the cylinder 31 is provided on the fork main body side surface of the ceiling portion 41.

  The taper surface 41a is inclined in a mortar shape from the outer peripheral end to the installation surface 41b on which the base member 34 is installed. When the base member 34 abuts on the taper surface 41a, the installation surface 41b follows the inclination of the taper surface 41a. Thus, the cylinder 31 can be aligned.

  For example, the cylinder 34 is inverted, the base member 34 is engaged with the base portion disposed above, and then the inner tube 2 screwed while the partition member 4 is attached to the bottom member 20 is covered with the cylinder 34. .

  Accordingly, the cylinder 34 can be inserted into the inner tube 2 while aligning the partition member 4, and the head member 30 and the partition member 4 can be inserted by screwing the head member 30 into the stopper member 5. The cylinder 31 is sandwiched between the two.

  Needless to say, the alignment of the cylinder 31 may be performed by a configuration other than the tapered surface 41a, or a curved surface 41c (FIG. 3) or another configuration may be adopted. As shown in FIGS. 3 and 4, the partition wall member 4 does not necessarily have the installation surface 41 b.

  Further, the cylindrical portion 40 includes an annular flange portion 40a protruding from the outer peripheral surface of the bottom member 20 side (lower side in FIG. 2), and the surface of the inner tube 2 is formed by the flange portion 40a. Receive pressure.

  Therefore, it is not necessary to provide the conventional washer W2, and it is possible to reduce the number of parts constituting the front fork and reduce the weight and simplification of the front fork.

  Further, since the partition member 4 is provided, there is no need to provide a conventional guide washer W1 for aligning the cylinder 31, and there is no possibility that the guide washer W1 generates burrs and damages the outer periphery of the cylinder 31.

  In addition, by defining the air chamber A with the partition member 4, it is possible to reduce the weight of the front fork by using the air chamber A as a portion filled with the conventional working fluid.

  In the present embodiment, since the cylindrical portion 4 and the inner tube 2 are in close contact with each other via the seal 43, the seal 21 is provided between the opening-side large opening portion 20a and the inner tube as in the prior art. There is no need to provide it.

  In the drawing, the bottom member 20 is formed in a bottomed cylindrical shape and the air chamber A is sealed. However, the bottom side opening of the fork main body is sealed by the partition member 4. The air chamber A and the outside air may be communicated.

  Further, by forming the partition member 4 in a cap shape, the volume of the air chamber A can be increased. However, the present invention is not limited thereto, and the partition member 4 may be formed in a disk shape. The shape of 4 can be selected as appropriate.

  In addition, although not shown, it goes without saying that a conventional washer W2 may be disposed on the upper surface of the flange portion 40a in the drawing and the surface pressure of the inner tube 2 may be received by this washer W2.

  Next, other embodiments of the partition member 4 of the front fork which is a fluid pressure shock absorber in the present embodiment will be described below.

  As shown in FIG. 5, the partition member 400 includes a cylindrical portion 401 formed in a cylindrical shape and a ceiling portion 403 that seals the ceiling surface of the cylindrical portion 401 and is formed in a cap shape. Become.

  The ceiling portion 403 is formed with a planar installation portion 404 on which the base member 34 is installed, and an annular projection 405 that protrudes along the outer periphery of the installation portion 404.

  By providing the above configuration, the partition member 400 can guide the base member 34 held on the bottom portion of the cylinder 31 by the annular protrusion 405 to the installation portion 404 when the cylinder 31 is inserted into the inner tube 2. 31 can be aligned.

  In addition, an annular flange portion 402 is formed on the lower end of the cylindrical portion 401 in the drawing, and the flange portion 402 is formed on the step portion of the bottom member 20 via a seal 406. Close to 20c.

  Therefore, the air chamber A can be defined inside the bottom member 20 by the partition member 400, and the front fork can be reduced in weight as compared with the conventional case, as with the partition member 4.

  In addition, the partition member 400 can align the cylinder 31 with the annular protrusion 405, and there is no need to provide the conventional guide washer W1, and there is no possibility of damaging the outer peripheral surface of the cylinder 31 with the guide washer W1.

  A washer W2 for receiving the surface pressure of the inner tube 2 is attached to the upper side of the flange portion 402 in the drawing, but this is not restrictive, and the flange portion 402 has a strength that can withstand the surface pressure of the inner tube 2. In the case of setting, it is not necessary to provide the washer W2.

  While the preferred embodiment of the present invention has been described above, it should be understood that modifications, variations and changes may be made without departing from the scope of the claims.

  For example, in the above embodiment, the present invention is embodied in the front fork. However, the present invention is not limited to this. For example, the present invention may be embodied in another fluid pressure buffer such as a rear cushion unit.

  In the above embodiment, the partition members 4 and 400 define the air chamber A inside the bottom member 20, but this is not a limitation, and the working fluid is accommodated in the room indicated by A in the figure, And the reservoir chamber R may be communicated with each other through a notch (not shown) of the base member 34.

A Air chamber C1, C2 Check valve G Air chamber J Coupling means P1 Extension side action chamber P2 Pressure side action chamber R Reservoir room S Suspension spring W1 Guide washer W2 Washer 1 Outer tube 2 Inner tube 3 Damper 4, 400 Partition member 5 Stopper member 6 Pin member 10 Cap member 11 Spring receiving case 20 Bottom member 20a Open side large opening 20b Back side small opening 20c Step 30 Head member 31 Cylinder 32 Rod 33 Piston 34 Base member 40, 401 Cylindrical portion 40a, 402 Flange Portions 41, 403 Ceiling 41a Tapered surface 41b Installation surface 41c Curved surface 404 Installation portion 405 Annular projection 60 Pin 61 Snap ring

Claims (6)

A shock absorber main body comprising an outer tube and an inner tube slidably inserted into the outer tube, and a bottom side opening of the shock absorber main body having a cylindrical space that opens to the shock absorber main body side A bottom member coupled to the outer periphery, and a damper that is housed in the shock absorber body and generates a predetermined damping force;
The damper is provided with a cylinder that stands up at the axial center of the inner tube and accommodates a working fluid therein,
The bottom portion of the inner tube is coupled to the inner periphery of the bottom member, and then the cylinder is inserted into the inner tube, and the head member and the bottom member are fixed to a coupling means coupled to the inner tube. In the fluid pressure damper that clamps the cylinder and fixes the cylinder to the bottom member,
A partition member for aligning the cylinder,
The bottom pressure member supports the cylinder via the partition wall member.   The fluid pressure shock absorber according to claim 1, wherein the partition member defines an air chamber in the bottom member.   3. The fluid pressure shock absorber according to claim 1, wherein the partition wall member includes a tapered surface that aligns the cylinder on a side surface of the shock absorber main body. 4. The bottom member is formed in a bottomed cylindrical shape, and is formed coaxially on the opening side large opening portion that forms a large-diameter columnar space that opens to the shock absorber body side, and on the back side of the columnar space. A back side small opening that forms a small-diameter columnar space, and a step formed between the opening side large opening and the back side small opening,
The said inner tube is fixed to the inner periphery of the said opening side large opening part, The said partition member is clamped between the said step part and the said inner tube, The Claim 1 characterized by the above-mentioned. Fluid pressure shock absorber. The partition member is formed in a cap shape with a cylindrical portion that closely contacts the outer periphery to the inner periphery of the inner tube, and a ceiling portion that seals the ceiling surface of the cylindrical portion,
The fluid pressure shock absorber according to any one of claims 1 to 4, further comprising a tapered surface that aligns the cylinder on a side surface of the fork main body of the ceiling portion. The cylindrical portion includes an annular flange portion protruding from the outer peripheral surface of the bottom member side end,
6. The fluid pressure shock absorber according to claim 5, wherein a surface pressure of the inner tube is received by the flange portion.

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