JP2009127847A - Double-rod damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the number of parts required for assembling from being increased without changing the characteristics of setting of a damping valve comprising an annular relief valve. <P>SOLUTION: This double-rod damper comprises one rod body 51 in which a piston body 4 slidably stored in a cylinder body 3 is interposed on the base end outer peripheral part thereof and the top end thereof extends to the outside of the cylinder body 3 through the one end 31a of the cylinder body 3 and the other rod body 52 in which the base end thereof is connected to the base end of the one rod body 51 and the top end thereof extends to the outside of the cylinder body 3 through the other end 31b of the cylinder body 3. In the double-rod damper, the base end of the rod body 52 is connected to the base end of one rod body 51 directly or through a connection member 7, and the end surface of the piston body 4 side at the base end of the other rod body 52 or the end of the connection member 7 is separated from the end surface of a fixing member 43 of the piston body 4. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a double rod type damper, and more particularly, to a double rod suitable for the realization of a front fork as a hydraulic shock absorber that is mounted on the front wheel side of a motorcycle and absorbs road surface vibrations input to the front wheel while suspending the front wheel. The present invention relates to an improvement of a mold damper.

  Various proposals have been made so far for a double rod type damper that is suitable for the realization of a front fork that is a hydraulic shock absorber that is mounted on the front wheel side of a motorcycle and absorbs road vibration input to the front wheel while suspending the front wheel. is there.

  For example, in the proposal disclosed in Patent Document 1, there is a double rod type damper disposed in a shaft core portion of a front fork composed of a vehicle body side tube and a wheel side tube, and not only one rod body but also the other rod body. The cylinder body is connected to a piston body that is housed under a fixed structure.

  Therefore, in the double rod type damper disclosed in Patent Document 1, in the damping valve composed of the annular leaf valve disposed on the piston body, tightening that is a coupling force when the other rod body is coupled to the piston body. Depending on the force adjustment, it is feared that the setting characteristics of the annular leaf valve, for example, the cracking pressure may be changed.

  Therefore, in order to stabilize the setting characteristics of the damping valve composed of the annular leaf valve in the double rod type damper, for example, as proposed in Patent Document 2, one rod body is connected to the piston body under a fixed structure. However, it is proposed to connect the other rod body to the piston body under an unfixed structure.

  Incidentally, in the double rod type damper disclosed in Patent Document 2, the proximal end portion of the other rod body is prevented from coming off while being allowed to move in the radial direction with respect to the holder member held by the piston body in the cylinder body. Linked to the mechanism.

Therefore, in the double rod type damper disclosed in Patent Document 2, the characteristics of the setting of the annular leaf valve depending on the adjustment of the tightening force as the connecting force when the other rod body is connected to the piston body, for example, There is no concern about changing the cracking pressure.
JP 2007-132485 A (see FIG. 3) JP 2004-293720 A (Abstract, paragraphs 0015 to 0017, 0042 to 0046 in the specification, see FIG. 2)

  However, in the proposal disclosed in Patent Document 2 described above, there is no problem in that the setting characteristics of the damping valve composed of the annular leaf valve are not changed when the double rod type damper is assembled. In light of this, it may be pointed out that there is a minor problem.

  That is, in the above-described double rod type damper, although it is via the holder member, the other end of the rod body is connected to the piston body while being separated from the piston body. .

  Specifically, the holder member is fixed to the lower end portion of the piston body while functioning as a valve stopper of a damping valve composed of an annular leaf valve, and the base end portion of the other rod body crosses the axial direction inside the lower end of the holder member. It is linked under the use of a stopper ring or the like to enable lateral movement as a direction.

  From this fact, it is expected that the number of related parts will increase when the rod body and the piston body are connected to each other, and there is a problem that the labor for assembly is increased, resulting in an increase in product cost. .

  The present invention was devised in view of such a current situation, and the object of the invention is not to change the setting characteristics of the damping valve composed of the annular leaf valve, but also to the assembly thereof. It is to provide a double rod type damper that is optimal for preventing a mischievous increase in the number of parts and expecting improvement in versatility in a front fork incorporating the same.

  In order to achieve the above object, the structure of the double rod type damper according to the present invention basically includes a cylinder body, a piston body slidably accommodated in the cylinder body, and a piston body based on the piston body. One rod body that protrudes out of the cylinder body through one end of the cylinder body while interposing the outer periphery of the end section, and a proximal end portion is connected to the proximal end portion of the one rod body, and the distal end is a cylinder An annular leaf valve having a rod body penetrating the other end of the body and projecting out of the cylinder body, the piston body being adjacent to the other rod body side while being interposed on the outer periphery of the base end portion of the one rod body In the double rod type damper in which the annular leaf valve is fixed to the piston body by a fixing member adjacent to the base end portion of the one rod body from the other rod body side, the other rod Is connected to the base end portion of one rod body directly or via a connecting member, while the end surface on the piston body side at the base end portion of the other rod body or the end portion of the connecting member is Assume that it is away from the end face.

  Therefore, in the present invention, since the base end portion of the other rod body is connected to the base end portion of the one rod body directly or via a connecting member, the number of parts required for assembly can be reduced, and the number of parts can be reduced. Therefore, it is possible to prevent an increase in the number of assembling steps caused by the increase, and to avoid an increase in product cost.

  In the present invention, since the end surface on the piston body side at the base end portion of the other rod body or the end portion of the connecting member is separated from the end surface of the fixing member, the space between the one rod body and the other rod body. When bending occurs, the external force accompanying the bending does not act on the damping valve composed of the annular leaf valve, and the setting characteristics of the damping valve are not changed.

  In the following, the present invention will be described based on the embodiment shown in FIG. 1 as a principle diagram and FIGS. 2 and 3 as specific examples of the main part. The double rod type damper according to the present invention is mounted on the front wheel side of a motorcycle. It is suitable for the realization of a front fork that is a hydraulic shock absorber that absorbs road surface vibrations input to the front wheel while suspending the front wheel.

  The front fork is connected to the vehicle body side tube 1 so that the wheel side tube 2 can protrude and retract, and the double rod type damper of the present invention is accommodated in the shaft core portion of the fork main body composed of the vehicle body side tube 1 and the wheel side tube 2. Disguise.

  The fork main body has a reservoir chamber R inside, and the reservoir chamber R has an air chamber A (see FIG. 1) bordering on the oil level O (see FIG. 1). The air chamber A is a contraction of the fork main body. Demonstrates air spring force during operation.

  And in this fork main body, the rod body 5 in the double rod type damper, that is, the upper rod body 51 as one rod body is suspended from the shaft core portion of the vehicle body side tube 1, and the shaft of the wheel side tube 2 is suspended. A cylinder body 3 that similarly forms the double rod type damper is disposed in the core portion.

  The upper end of the rod body 5, that is, the upper end of the upper rod body 51 is connected to a cap portion 1 a (see FIG. 1) that closes the upper end opening of the vehicle body side tube 1, and the cylinder body 3 includes a sub cylinder portion 32 described later. It connects with the bottom part 2a (refer FIG. 1) which obstruct | occludes the lower end opening of the wheel side tube 2 via.

  The suspension spring 6 is located between the cylinder body 3 and the vehicle body side tube 1 (see FIG. 1), and the wheel side tube 2 is pulled out of the vehicle body side tube 1 by the spring force. The fork body is biased in the direction of extension, that is, in the extending direction.

  On the other hand, the double rod type damper includes the cylinder body 3, the piston body 4, and the rod body 5, that is, the upper rod body 51 and the lower rod body 52 that is the other rod body, and further includes a connecting member. 7.

  If it demonstrates a little, the cylinder body 3 has the main-body part 31 which accommodates the piston body 4 so that sliding is possible, obstruct | occludes the upper end opening of this main-body part 31, and is the upper end part 31a which is one edge part used as a bearing part. In addition, an oil chamber space is defined inside the main body 31 by providing a lower end 31b which is the other end of the main body 31 that closes the lower end opening of the main body 31.

  Therefore, in the illustrated front fork, the inside of the main body portion 31 of the cylinder body 3 forming the double rod type damper is not in fear of the occurrence of aeration due to having the reservoir chamber R in principle.

  That is, as is well known, in the single rod type damper, the pressure side oil chamber in the cylinder body communicates with the reservoir chamber outside the cylinder body, and particularly when the hydraulic oil is insufficient in the pressure side oil chamber, it operates from the reservoir chamber. Oil is replenished.

  Therefore, when air is mixed into the hydraulic oil due to the oil level being disturbed in the reservoir chamber, the hydraulic oil mixed with the air flows into the pressure side oil chamber in the cylinder body, and the hydraulic oil is contained in the hydraulic oil in the pressure side oil chamber. There is a concern that aeration may occur due to air mixed into the air.

  However, in the double rod type damper of the present invention, since the hydraulic oil does not reciprocate between the cylinder body 3 and the outside of the cylinder body 3, even if the reservoir chamber R is provided outside the cylinder body 3, generation of aeration occurs. Do not be afraid.

  By the way, in this cylinder body 3, the sub cylinder part 32 which defines sub oil chamber R3 which makes the front end side of the lower rod body 52 mentioned later exist is connected with the lower end part 31b in the main-body part 31.

  The sub-cylinder portion 32 is erected on the shaft core portion of the wheel side tube 2 while extending from the main body portion 31 to the same diameter, and the opening end serving as the lower end is closed by the bottom portion 2 a of the wheel side tube 2. In addition, the inside is communicated with the outside of the sub-cylinder portion 32, that is, the above-described reservoir chamber R through a communication hole 32a (see FIG. 1) provided at the lower end.

  Incidentally, although not shown, the main body 31 of the cylinder body 3 has a small hole at a position near the upper end 31a, and air mixed into the hydraulic oil in the upper oil chamber R1 through this small hole is stored in the reservoir chamber. You may be allowed to exit R.

  The piston body 4 is slidably accommodated in the main body 31 in the cylinder body 3 and defines an upper oil chamber R1 and a lower oil chamber R2 that do not have a pressure receiving area difference in the main body 31. In addition, an expansion side damping valve 41 and a pressure side damping valve 42 that generate a damping force of a predetermined magnitude while allowing communication between both the oil chambers R1, R2 are provided.

  Incidentally, although not shown, the piston body 4 has a bypass passage that bypasses the damping valves 41 and 42 and allows communication between the upper oil chamber R1 and the lower oil chamber R2, and is disposed in the bypass passage. The amount of oil passing through the bypass passage is adjusted by the operation of an adjusting valve that is a means for adjusting the amount of passing oil driven by appropriate means, and the level of the damping force generated by the damping valves 41 and 42 can be adjusted. Also good.

  The rod body 5, that is, the upper rod body 51 and the lower rod body 52, as shown in the drawing, each base end is connected to both ends which are the upper and lower ends in FIG. Passes through the shaft core portion of the upper end portion 31 a or the lower end portion 31 b of the main body portion 31 and protrudes outward in the axial direction of the main body portion 31.

  Each of the upper rod body 51 and the lower rod body 52 is preferably made of a pipe body, and by being made of a pipe body, the weight of the rod body 5 is reduced and the overall weight of the double rod type damper is reduced. This also contributes to ensuring the mechanical strength against bending in the rod body 5.

  The top end of the upper rod body 51 in the drawing is connected to the vehicle body side tube 1 as described above, and the bottom end of the lower rod body 52 in the drawing penetrates the lower end portion 31b of the main body 31. Then, it protrudes into the sub oil chamber R3 in the sub cylinder portion 32.

  The upper end 31a and the lower end 31b of the main body 31 have a bearing member (not shown), and the slidability of the upper rod body 51 and the lower rod body 52 is ensured by this bearing member.

  Since the bearing member allows sliding leakage of the hydraulic oil with respect to the rod body 5, the hydraulic oil mixed with air in the upper oil chamber R1 defined in the main body 31 of the cylinder body 3 is It flows out of the cylinder body 3, that is, into the reservoir chamber R through the inner peripheral side of the bearing member.

  Therefore, in the above-described double rod type damper, when the piston body 4 slides in the main body 31 of the cylinder body 3, both the oil chambers R1, R2 are communicated with each other via the damping valves 41, 42. A damping force on each predetermined side is generated.

  For this reason, in the front fork, the fork main body expands and contracts while generating a predetermined damping force on each side by the expansion and contraction operation of the built-in double rod type damper.

  By the way, in the double rod type damper of the present invention, the upper rod body 51 and the lower rod body 52 as the rod body 5 are integrally connected under the use of the connecting member 7 as shown in FIG. .

  In FIG. 1, there is a gap S between the connecting member 7 and the piston body 4, and in FIG. 2, there is a gap S between the connecting member 7 and the piston nut 43 serving as a fixing member. And it is said that the two will be separated.

  The connecting member 7 is formed in a cylindrical shape as shown in FIG. 2, with the upper end side in the drawing screwed to the upper end of the upper rod body 51, and on the lower end side in the drawing. Assume that the base end portion of the lower rod body 52 is screwed, and when the connecting member 7 is screwed to the base end portion of the upper rod body 51, the upper end thereof faces the piston nut 43 with a gap S therebetween. Care is taken not to interfere.

  Further, the connecting member 7 is basically made of the same material as that forming the rod body 5, but from the viewpoint of allowing bending between the upper rod body 51 and the lower rod body 52, the rod A material that is less rigid than the material that forms the body 5 or that is more elastic than the material that forms the rod body 5 may be selected.

  Therefore, in the double rod type damper of the present invention, since the other rod body 52 is integrally connected to the one rod body 51 via the connecting member 7, the number of parts required for assembly can be reduced, and the number of parts can be reduced. Therefore, it is possible to prevent an increase in the number of assembling steps caused by increasing the number of steps, and to avoid an increase in product cost.

  Not only depending on the rigidity of the connecting member 7, but the one rod body 51 and the other rod body 52 are integrally formed, that is, compared with the case where the one rod body 51 and On the other hand, the bending between the rod body 52 and the rod body 52 is allowed, and the occurrence of the twisting phenomenon of the piston body 4 with respect to the main body 31 in the cylinder body 3 is not feared.

  And in the double rod type damper of the present invention, the end face on the piston body 4 side at the end which is the upper end in FIG. 1 of the connecting member 7 for connecting the other rod body 52 to the one rod body 51 is the piston body. 4 is separated from the end face 4 with a gap S. For example, when bending is developed between the one rod body 51 and the other rod body 52, the external force accompanying the bending is applied to the piston body 4, that is, 2, the set characteristic in the damping valve 41 (and the damping valve 42) composed of an annular leaf valve that does not act on the piston nut 43 and is fixed to the piston body 4, for example, cracking pressure, is shown. Do not change.

  The above is the operation and effect of the double rod type damper according to the present invention. However, the front fork incorporating the double rod type damper may be formed as shown in FIG.

  That is, in the front fork shown in FIG. 3, both rod type dampers are equipped with an oil lock structure, and this oil lock structure will be described a little.

  In the double rod type damper shown in FIG. 3, the lower rod body 52 has the oil lock piece 8 constituting the oil lock structure, and the oil lock structure is similarly provided on the lower end portion 31 b of the main body 31 in the cylinder body 3. An oil lock case 9 that is formed and fitted with the oil lock piece 8 is provided.

  The oil lock piece 8 is formed in an annular shape or a cylindrical shape, and in principle, is held by an appropriate means on the outer periphery of the lower rod body 52 existing in the lower oil chamber R2 in the main body 31 in the cylinder body 3, As shown in the figure, it is interposed on the outer periphery of a connecting member 53 that connects the upper rod body 51 and the lower rod body 52 described above.

  On the other hand, the oil lock case 9 is formed in a bottomed cylindrical shape whose upper end is open toward the piston body 4 as shown in the figure, and the bottom portion 91 is provided with the lower end portion 31b of the main body portion 31 in the cylinder body 3. The lower rod body 52 is passed through the shaft core portion while being formed.

  The oil lock case 9 has a cylindrical portion 92 erected upward from the bottom 91, and the cylindrical portion 92 allows the oil lock piece 8 to be fitted inside. To do.

  On the other hand, in the oil lock case 9, the cylindrical portion 92 also serves as a connecting member that connects the main body portion 31 and the sub-cylinder portion 32 in the cylinder body 3. In combination with the formation of the lower end 31b of the main body 31, the number of parts constituting the double rod type damper is reduced.

  Therefore, in the oil lock structure comprising the oil lock piece 8 and the oil lock case 9, this is provided in the lower oil chamber R2 defined by the piston body 4 in the cylinder body 1 of the double rod type damper. In addition, since the lower oil chamber can be lengthened by shortening the sub-cylinder portion, the stroke that ensures the operation of the oil lock structure does not reduce the expansion / contraction stroke of the damper. Predetermined impact relaxation can be realized while ensuring a damping action based on a predetermined expansion / contraction stroke.

  The oil lock piece 8 includes a main body 81, a holder 82, and a cushion 83. The main body 81 is held on the outer periphery of the lower rod body 52 by screwing the holder 82 to the lower rod body 52 side, 83 is press-fitted into the outer periphery of the lower rod body 52 in a state of being serially connected to the holder 82.

  The main body 81 is sandwiched between the holder 82 and the above-described connecting member 53 while being interposed with a clearance channel on the outer periphery of the holder 82, and a lower end portion carried by the holder 82. And a notch passage 81 a communicating with the gap channel and the outside of the main body 81.

  Therefore, in the main body 81 of this oil lock piece 8, assuming that there is no flow of hydraulic oil on the outer peripheral side of the main body 81, when the oil lock piece 8 is in the rising state illustrated in FIG. Although communication between the upper and lower sides of the main body 81 is prevented and not shown, when the lower body is in a lowered state, the gap passage is opened to allow communication between the upper and lower sides of the main body 81.

  In the oil lock structure comprising the oil lock piece 8 and the oil lock case 9 formed as described above, when the oil lock piece 8 is fitted into the oil lock case 9, basically, the body 81 The outer periphery slides into contact with the inner periphery of the cylindrical portion 92 in the oil lock case 9, and then the lower end of the cushion 83 in the drawing is in contact with the bottom portion 91 in the oil lock case.

  However, as long as the effect of mitigating the impact is obtained, the oil lock piece 8 is not provided with the cushion 83 and only has a main body 81, and the main body 81 has a cylindrical portion 92 in the oil lock case 9. The desired impact relaxation may be realized by fitting to.

  By the way, compared with the case of the oil lock structure, there is a concern about the occurrence of repulsive force when the cushion 83 contracts when the shock is reduced by the cushion 83, but from the viewpoint of achieving the original purpose of shock reduction, Only the cushion 83 may be provided without the main body 81.

  When the front fork is contracted most and the main body 81 of the oil lock piece 8 is fitted into the cylindrical portion 92 of the oil lock case 9, the main body 81 is maintained in the above-described raised state. A locked state appears and predetermined shock relaxation is achieved.

  At this time, the oil lock piece 8 has an axial force so as to move toward the piston body 4 side on the outer periphery of the connecting member 53, but as described above, the connecting member 53 removes the clearance S from the piston nut 43. Have to be away.

  Therefore, the axial force of the oil lock piece 8 is not transmitted to the piston nut 43, and therefore the setting characteristics of the annular leaf valve constituting the damping valve 41 that is fixed to the piston body 4 by the piston nut 43 are changed. I won't let you.

  In addition, when the main fork 81 in the oil lock piece 8 comes out of the cylindrical portion 92 in the oil lock case 9 by the front fork changing from the most contracted state to the extending operation, the main body 81 is in the lowered state described above. Thus, the hydraulic oil is allowed to flow into the cylindrical portion 92, and the main body 81 is allowed to escape.

  The shock relaxation when the double rod type damper is fully extended is due to the contraction operation of the extension spring 10 disposed above the piston body 4.

  As described above, the case where the front fork is an inverted type in which the vehicle body side tube 1 is an outer tube and the wheel side tube 2 is an inner tube is taken as an example. However, in the double rod damper of the present invention, Although not shown in the figure, even if it is an upright type in which the vehicle body side tube 1 is an inner tube and the wheel side tube 2 is an outer tube, it can be used, and the effects in that case are not different.

It is a figure which shows in principle the front fork which incorporates the double rod type damper of this invention. It is a longitudinal cross-sectional view which partially enlarges and shows one Embodiment of the front fork incorporating the double rod type damper by this invention. It is a figure which shows other embodiment of the front fork incorporating the double rod type damper by this invention similarly to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Cylinder body 4 Piston body 5 Rod body 7 Connection member 8 Oil lock piece 9 Oil lock case 31 Main body part 31a which comprises a cylinder body Upper end part 31b which is one end part 43 Lower end part which is another end part 43 Piston nut 51 which is a fixing member Upper rod body as rod body 52 Lower rod body as rod body

Claims (4)

A cylinder body, a piston body slidably accommodated in the cylinder body, and a distal end of the cylinder body that protrudes outside the cylinder body through one end of the cylinder body while the piston body is interposed on the outer periphery of the base end portion A rod body that is connected to a base end portion of the one rod body, and a rod body that protrudes out of the cylinder body through the other end of the cylinder body. On the other hand, an annular leaf valve adjacent to the other rod body is seated on the outer periphery of the base end of the rod body, and this annular leaf valve is adjacent to the proximal end of the one rod body from the other rod body side. In the double rod type damper fixed to the piston body by the fixing member, the base end portion of the other rod body is connected to the base end portion of the one rod body directly or via the connecting member, while the other Double rod type damper end face of the piston side at the end of the head body of the proximal portion or the connecting member is characterized by comprising away from the end face of the fixing member. 2. The fixing member is a piston nut that is screwed to the base end portion of one rod body from the other rod body side and seats the inner peripheral side portion of the annular leaf valve in a fixed state on the inner peripheral side portion of the piston body. Double rod type damper as described in 1. 2. The double rod damper according to claim 1, wherein a base end portion or a connecting member of the other rod body is provided with an oil lock piece formed in an annular shape or a cylindrical shape on the outer periphery. An oil lock case is disposed at the other end of the cylinder body, and an oil lock piece interposed on the base end of the other rod body or the outer periphery of the connecting member can be fitted into the oil lock case. The double rod type damper according to claim 3.

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