阅读说明：本技术 限位器和缓冲器 (Stopper and buffer ) 是由 加藤宽仁 山本直纪 于 2016-09-16 设计创作，主要内容包括：限位器(100)包括盖(110)、用于承接冲撞垫(40)的止挡件(120)、及轴环(130)。盖(110)具有板状部(111)和筒状部(115),该板状部(111)具有能够供活塞杆(30)贯穿的杆孔(112),该筒状部(115)能够接纳缸体(10)。冲撞垫(40)设于板状部(111)。轴环(130)与缸体(10)相对地设于板状部(111)。(The retainer (100) includes a cover (110), a stopper (120) for receiving the impact pad (40), and a collar (130). The cap (110) has a plate-shaped portion (111) and a cylindrical portion (115), the plate-shaped portion (111) having a rod hole (112) through which the piston rod (30) can pass, the cylindrical portion (115) being capable of receiving the cylinder (10). The collision pad (40) is provided on the plate-shaped portion (111). The collar (130) is provided on the plate-shaped portion (111) so as to face the cylinder (10).)

1. A stopper for absorbing an impact generated when a bumper is maximally contracted in cooperation with an impact pad, wherein,

this stopper includes:

a cover having a plate-shaped portion having a rod hole through which a piston rod of the shock absorber can pass, and a cylindrical portion capable of receiving a part of a cylinder of the shock absorber;

a stopper provided on the plate-like portion and receiving the collision pad; and

a collar provided on the plate-like portion so as to face the cylinder,

the wall thickness of the cap is thinner than the thickness of the stop and the collar,

the cylindrical portion has a shape capable of being fixed to an outer peripheral surface of the cylinder.

2. The retainer of claim 1,

an inner circumferential surface of the stopper is located radially inward of an inner circumferential surface of the rod hole of the plate-shaped portion.

3. The retainer according to claim 1 or 2,

the stop and the collar are secured to the cap with a projection weld.

4. A buffer, wherein the buffer is provided with a buffer body,

the buffer includes:

a stopper according to any one of claims 1 to 3;

a cylinder, a part of which is received in the cylindrical portion; and

a piston rod inserted into the cylinder body so as to be freely advanced and retracted, and inserted through the rod hole;

the cylinder block includes:

a cylinder barrel; and

an oil seal provided on an inner periphery of the cylinder and in sliding contact with an outer peripheral surface of the piston rod,

the oil seal is fixed to the cylinder barrel by bending the end of the cylinder barrel to be axially opposite to the oil seal,

the collar is provided in the cylinder tube and bent between the end portion axially opposite to the oil seal and the plate-like portion to separate the oil seal and the plate-like portion.

5. A buffer, wherein the buffer is provided with a buffer body,

the buffer includes:

a stopper according to any one of claims 1 to 3;

a cylinder, a part of which is received in the cylindrical portion; and

a piston rod inserted into the cylinder body so as to be freely advanced and retracted, and inserted through the rod hole;

the cylinder block includes:

a cylinder barrel; and

an oil seal provided on an inner periphery of the cylinder and in sliding contact with an outer peripheral surface of the piston rod,

the oil seal is fixed to the cylinder tube by bending an end portion of the cylinder tube and extends from the cylinder tube along the piston rod,

the collar is disposed in the cylinder barrel and bent between the end portion from which the oil seal extends and the plate portion to separate the oil seal from the plate portion.

Technical Field

The invention relates to a stopper and a buffer having the stopper.

Background

There is known a stopper for absorbing an impact generated when the bumper is most contracted (JP 4048083B2, JP 9-317811 a). The stoppers disclosed in JP4048083B2 and JP 9-317811 a are mounted on an end of a cylinder into which a piston rod is movably inserted or an end of an outer cylinder for housing the cylinder. The stopper and a bump cushion (bump cushion) provided at the upper end of the piston rod absorb the impact when the piston rod is contracted to the maximum.

The stopper disclosed in JP4048083B2 has: a horizontal plate portion for receiving the collision pad; a folding part extending downward from the horizontal plate part and folded; and a communication hole formed at the folded portion. A through hole through which the piston rod passes is provided in the center of the horizontal plate portion. The folded portion is placed on the end of the cylinder in a state where the piston rod is inserted through the through hole of the horizontal plate portion, and a space is secured between the horizontal plate portion and the cylinder. The muddy water and dust flowing into the space from the gap between the horizontal plate portion and the piston rod are discharged to the outside of the stopper through the communication hole of the folded portion.

A disc-shaped stopper is disclosed in JP 9-317811 a. A protruding strip is formed on the lower surface of the disc-shaped stopper. The top end of the protruding strip is welded to the riveting part of the outer barrel of the buffer, and a space is ensured between the flat plate part of the stopper and the riveting part by the protruding strip. The dust flowing into the space from the gap between the stopper and the piston rod is discharged through a passage formed in the lower surface of the flat plate portion.

Disclosure of Invention

In the stopper disclosed in JP4048083B2, the folded portion is formed by folding a tube or a flat plate by press working. Since the bending angle is large (about 180 degrees) at the folded portion, the folded portion is liable to crack when the tube or the flat sheet is folded. Therefore, the manufacture of the stopper requires a high degree of skill.

In the stopper disclosed in JP 9-317811 a, the projected strip is formed by recessing a part of the upper surface of the flat plate. Therefore, when the bumper is compressed to the maximum and receives an impact from the impact pad, the stopper is likely to be deformed back to the original flat plate without the projection and the recess, and the strength may be insufficient.

Thus, the stoppers disclosed in JP4048083B2 and JP 9-317811 a have complicated shapes such as folded portions and protruding strips. Therefore, the manufacture of the stopper is difficult, and there is a possibility that the stopper does not have sufficient strength.

The invention aims to provide a stopper which is easy to manufacture and has enough strength.

The present invention relates to a stopper that absorbs an impact generated when a bumper is maximally contracted in cooperation with an impact pad. According to one aspect of the present invention, a stopper includes: a cap having a plate-shaped portion having a rod hole through which a piston rod of the shock absorber can pass, and a cylindrical portion capable of receiving a part of a cylinder of the shock absorber; a stopper provided on the plate-like portion and receiving the collision pad; and a collar provided on the plate-like portion so as to face the cylinder.

Drawings

Fig. 1 is a sectional view of a shock absorber including a stopper according to embodiment 1 of the present invention.

Fig. 2 is a front view of the stopper shown in fig. 1.

Fig. 3 is a bottom view of the retainer shown in fig. 1.

Fig. 4A is a bottom view of the collar shown in fig. 1 and 3.

Fig. 4B is a bottom view of the cover shown in fig. 1 and 3.

Fig. 4C is a bottom view of the stopper shown in fig. 1 and 3.

Fig. 5 is a bottom view of a stopper according to a modification of embodiment 1.

Fig. 6 is a cross-sectional view of the damper shown in fig. 1, and shows a state in which the damper is contracted.

Fig. 7 is a sectional view of a shock absorber having a stopper according to embodiment 2 of the present invention.

Fig. 8 is a bottom view of the retainer of fig. 7.

Fig. 9 is a sectional view taken along line IX-IX in fig. 8.

Fig. 10 is a sectional view of a shock absorber having a stopper according to embodiment 3 of the present invention.

Fig. 11 is a bottom view of the retainer of fig. 10.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings. Here, a hydraulic shock absorber using hydraulic oil as the working fluid will be described, but another fluid such as hydraulic water may be used as the working fluid.

< embodiment 1 >

First, a stopper 100 according to embodiment 1 of the present invention and a shock absorber 1 having the stopper 100 will be described with reference to fig. 1 to 4C. The damper 1 is provided between, for example, a vehicle body 5 and an axle (not shown) of the vehicle, and generates a damping force to suppress vibration of the vehicle body 5.

As shown in fig. 1, the shock absorber 1 includes a cylinder 10 in which hydraulic oil is sealed, and a piston rod 30 which is inserted into the cylinder 10 so as to be movable forward and backward. A piston (not shown) is slidably housed in the cylinder 10, and one end of the piston rod 30 is connected to the piston. The interior of the cylinder 10 is divided by a piston into an extension-side chamber 11 and a compression-side chamber, not shown.

The cylinder 10 has: a cylinder tube 12 having a substantially cylindrical shape; and a rod guide 13 and an oil seal 14, the rod guide 13 and the oil seal 14 being provided at one end portion of the cylinder tube 12. The rod guide 13 and the oil seal 14 are fixed to the cylinder tube 12 by bending the end portion of the cylinder tube 12 inward.

The rod guide 13 is formed in a ring shape, and a bush 15 is provided on the inner periphery of the rod guide 13. The piston rod 30 is slidably supported by the rod guide 13 via a bush 15.

The oil seal 14 includes an annular metal base 14a and lip portions 14b and 14c provided on the inner periphery of the metal base 14 a. The lips 14b and 14c are bonded to the metal base 14a by vulcanization bonding.

The lip portion 14b is in sliding contact with the piston rod 30, and prevents the working oil in the cylinder 10 from leaking to the outside. The lip portion 14c is in sliding contact with the piston rod 30 for preventing foreign matter from flowing into the cylinder 10.

The other end of the piston rod 30 is formed with an external thread portion 31. The piston rod 30 is fixed to the vehicle body 5 by screwing a nut, not shown, to the male screw portion 31 in a state where the male screw portion 31 is inserted through the hole 5a of the vehicle body 5.

A bottom member (not shown) is attached to the other end of the cylinder tube 12, and the opening of the cylinder tube 12 is closed by the bottom member. The base member is provided with a connecting portion (not shown) for attachment to an axle, and the base member (cylinder 10) is connected by the connecting portion.

The piston includes a 1 st piston passage and a 2 nd piston passage that communicate between the expansion side chamber 11 and the compression side chamber. A1 st damping valve is provided in the 1 st piston passage, and a 2 nd damping valve is provided in the 2 nd piston passage.

The 1 st damping valve opens by a pressure difference between the compression-side chamber and the expansion-side chamber 11 when the shock absorber 1 contracts, opens the 1 st piston passage, and applies resistance to the flow of the hydraulic oil moving from the compression-side chamber to the expansion-side chamber 11 through the 1 st piston passage. The 1 st damping valve closes the 1 st piston passage when the shock absorber 1 extends.

The 2 nd damping valve opens by a pressure difference between the expansion side chamber 11 and the compression side chamber when the shock absorber 1 expands, opens the 2 nd piston passage, and applies resistance to the flow of the hydraulic oil moving from the expansion side chamber 11 to the compression side chamber through the 2 nd piston passage. Further, the 2 nd damping valve closes the 2 nd piston passage when the shock absorber 1 contracts.

In this way, the shock absorber 1 generates a damping force in accordance with the expansion and contraction operation, and suppresses vibration of the vehicle body 5.

The shock absorber 1 further includes a collision pad 40 provided on the outer periphery of the piston rod 30 between the cylinder 10 and the vehicle body 5, and a stopper 100 attached to the cylinder 10.

The impact pad 40 is formed of a shrinkable material. When the shock absorber 1 contracts, the impact pad 40 contacts the stopper 100 and contracts, thereby absorbing the impact generated by the operation of the shock absorber 1. Thus, the stopper 100 absorbs the impact generated when the bumper 1 is maximally contracted in cooperation with the impact pad 40.

As shown in fig. 1 to 3, the stopper 100 includes: a cap 110 covering an upper end side of the cylinder 10; a stopper 120 supported by the cover 110; and a collar 130 provided inside the cover 110.

The cover 110 includes: a plate-shaped portion 111 having a 1 st rod hole 112 through which the piston rod 30 can pass; and a cylindrical portion 115 capable of receiving an upper end side of the cylinder 10. The 1 st rod hole 112 is formed to penetrate between the 1 st surface (inner surface) 111a and the 2 nd surface (outer surface) 111b of the plate-shaped portion 111. Hereinafter, the 1 st rod hole 112 is also simply referred to as "rod hole 112".

Fig. 4A, 4B, and 4C are bottom views of the collar 130, the cap 110, and the stopper 120, respectively. Fig. 4A, 4B, and 4C depict the piston rod 30 with a one-dot chain line.

As shown in fig. 4B, the lever hole 112 is located substantially at the center of the plate-like portion 111. The inner circumferential surface of the rod hole 112 has a plurality of curved surface portions 112a formed in an arc shape and a plurality of concave surface portions 112b formed to be recessed from the curved surface portions 112a toward the outer side of the plate-like portion 111. Concave surface 112b defines a substantially rectangular opening 112 c.

In the present embodiment, each concave surface portion 112b is formed by 3 flat surfaces, but may be formed by 1 curved surface. When the concave surface portion 112b is formed by 1 curved surface, the opening portion 112c is divided into a substantially semicircular shape.

The centers of the arcuate curved surface portions 112a are substantially aligned, and the radius of curvature of the curved surface portion 112a is larger than the radius of the piston rod 30. Therefore, in a state where the stopper 100 is attached to the cylinder 10 (see fig. 1), a gap is formed between the inner wall surface of the rod hole 112 and the piston rod 30.

As shown in fig. 1 to 3, the cylindrical portion 115 is formed continuously with the plate-like portion 111. In a state where the cylindrical portion 115 receives the cylinder block 10, the inner surface 111a of the plate-shaped portion 111 faces the end surface (oil seal 14) of the cylinder block 10.

The cylindrical portion 115 has a plurality of protrusions 116 protruding inward. The plurality of protrusions 116 are formed by recessing the outer peripheral surface of the cylindrical portion 115. In a state where the cylindrical portion 115 receives the cylinder 10, the plurality of protrusions 116 abut against the outer circumferential surface of the cylinder 10 so as to push the cylindrical portion 115 open. Therefore, a relatively large force is required to pull the cylinder 10 from the cap 110, and the cap 110 can be prevented from being detached from the cylinder 10.

The stopper 120 is provided on the outer surface 111b of the plate-shaped portion 111, and is fixed to the cover 110 by projection welding. The impact pad 40 is caught by the stopper 120 when the bumper 1 is contracted.

A circular 2 nd rod hole 121 is formed substantially at the center of the stopper 120 (see fig. 4C). The stopper 100 is attached to the cylinder 10 in a state where the piston rod 30 is inserted into the 2 nd rod hole 121.

The inner circumferential surface of the 2 nd rod hole 121 of the stopper 120 is located inward of the inner circumferential surface of the rod hole 112 of the plate-shaped portion 111. Therefore, the clearance between the stopper 120 and the piston rod 30 is smaller than the clearance between the plate-shaped portion 111 and the piston rod 30. Therefore, regardless of the size of the rod hole 112 of the plate-shaped portion 111, the collision pad 40 is less likely to enter the gap between the stopper 120 and the piston rod 30, and damage to the collision pad 40 can be prevented.

Further, since the stopper 120 is provided to the outer surface 111b of the plate-shaped portion 111, the stopper 120 is separated from the oil seal 14 in the axial direction of the piston rod 30. Thus, even if the clearance between the stopper 120 and the piston rod 30 is narrowed, contact of the stopper 120 and the oil seal 14 (more specifically, the lip portion 14c) can be prevented.

Since the clearance between the plate-shaped portion 111 and the piston rod 30 is larger than the clearance between the stopper 120 and the piston rod 30, the inner peripheral surface of the rod hole 112 of the plate-shaped portion 111 is separated from the lip portion 14c in the radial direction of the piston rod 30. Therefore, even if the interval between the plate-shaped portion 111 and the cylinder block 10 is narrowed, the contact of the plate-shaped portion 111 and the lip portion 14c can be prevented.

The collar 130 is provided on the inner surface 111a of the plate-shaped portion 111, and is fixed to the cover 110 by projection welding. In a state where the stopper 100 is attached to the cylinder 10, the collar 130 faces the cylinder 10 to separate the plate-shaped portion 111 from the cylinder 10. Therefore, the stopper 120 is sufficiently separated from the oil seal 14, and contact of the stopper 120 and the oil seal 14 can be more reliably prevented.

As shown in fig. 3 and 4A, the collar 130 includes a plurality of support portions 131 for supporting the plate-shaped portion 111, and a plurality of coupling portions 132 for coupling the adjacent support portions 131. The plurality of support portions 131 are integrated by the coupling portion 132. That is, the collar 130 is formed as 1 member. Therefore, when the collar 130 is attached to the cover 110, the collar 130 can be easily handled. The same effects are also obtained in embodiment 2 and embodiment 3 described later.

A circular 3 rd rod hole 133 is formed in the collar 130 by the plurality of support portions 131 and the plurality of coupling portions 132. The stopper 100 is attached to the cylinder 10 in a state where the piston rod 30 is inserted through the 3 rd rod hole 133 of the collar 130.

The radius of the 3 rd rod hole 133 of the collar 130 is identical to the radius of curvature of the curved surface portion 112a of the plate-shaped portion 111, and the inner circumferential surface of the 3 rd rod hole 133 and the curved surface portion 112a are continuous without a step. Since the clearance between the plate-shaped portion 111 and the piston rod 30 is larger than the clearance between the stopper 120 and the piston rod 30, the inner peripheral surface of the 3 rd rod hole 133 continuous with the curved surface portion 112a of the plate-shaped portion 111 without a step difference is sufficiently separated from the lip portion 14c in the radial direction of the piston rod 30. Thus, contact of the collar 130 and the lip 14c is prevented.

The plurality of support portions 131 are radially arranged between the adjacent openings 112 c. Thus, radial passages 140 communicating with the opening 112c of the rod hole 112 are formed between the adjacent support portions 131. The passage 140 communicates with the outside of the cylindrical portion 115 via a gap between the outer peripheral surface of the cylinder 10 and the inner peripheral surface of the cylindrical portion 115.

The term "outside of the cylindrical portion 115" refers to a space other than the inside of the cylindrical portion 115, and specifically includes a space on the left side of the left end of the cylindrical portion 115, a space on the right side of the right end of the cylindrical portion 115, a space above the upper end of the cylindrical portion 115, and a space below the lower end of the cylindrical portion 115 in fig. 1. In the present embodiment, the passage 140 communicates with the space below the lower end of the cylindrical portion 115 via the gap between the outer peripheral surface of the cylinder 10 and the inner peripheral surface of the cylindrical portion 115.

Since the passage 140 is formed between the adjacent support portions 131, the passage forming portion of the plate-shaped portion 111 is supported by the support portions 131 on both sides and is not easily deformed. Therefore, the cross-sectional shape of the passage 140 can be prevented from being deformed, and the fluid and dust flowing into the cover 110 from the rod hole 112 of the plate-shaped portion 111 can be more reliably discharged to the outside of the cover 110.

As the collision pad 40 contracts, air flows around the collision pad 40. By the flow of the fluid, the fluid and dust may flow into the gap between the inner circumferential surface of the rod hole 112 of the plate-shaped portion 111 and the piston rod 30. Further, a liquid such as water may flow into a gap between the inner peripheral surface of the rod hole 112 of the plate-shaped portion 111 and the piston rod 30.

In the present embodiment, the passage 140 communicates the rod hole 112 of the plate-shaped portion 111 and the outside of the cylindrical portion 115 via the inside of the cylindrical portion 115. Therefore, the fluid and dust flowing into the gap between the inner circumferential surface of the rod hole 112 of the plate-shaped portion 111 and the piston rod 30 are discharged to the outside of the cap 110 through the opening 112c of the rod hole 112 and the passage 140.

The coupling portion 132 extends across the opening 112c of the rod hole 112 radially inward of the concave surface portion 112 b. Therefore, the passage 140 communicates with the opening 112c of the rod hole 112. Therefore, the flow in the passage 140 is not blocked by the connection portion 132, and the fluid and dust flowing into the cap 110 from the rod hole 112 can be more reliably discharged to the outside of the cap 110.

The coupling portion 132 is not recessed with respect to the support portion 131, but is formed in a planar shape along the support portion 131. Thus, the collar 130 becomes simple. Further, it is not necessary to consider a gap between the coupling portion 132 and the stopper 120 in order to prevent the coupling portion 132 and the stopper 120 from contacting each other, and it is easy to manufacture a collar.

The passage 140 has a flow path cross section larger than that of the clearance between the stopper 120 and the piston rod 30. Therefore, the fluid and dust flowing into the passage 140 from the gap are less likely to stay in the passage 140. Therefore, the fluid and dust flowing into the cover 110 from the rod hole 112 can be more reliably discharged to the outside of the cover 110.

In the present embodiment, since the passage 140 that communicates the rod hole 112 and the outside of the cap 110 is formed by the cap 110 and the collar 130, it is not necessary to form the cap 110 into a complicated shape. Thus, the stopper 100 can be easily formed, and the strength of the stopper 100 can be prevented from being reduced.

Fig. 5 is a bottom view of the stopper 101 showing a modification of the present embodiment. As shown in fig. 5, a circular rod hole 112 is formed in the plate-like portion 111. The collar 130 does not have a portion corresponding to the coupling portion 132 (see fig. 3 and 4A), and the plurality of support portions 131 are separated from each other. In this stopper 101, a passage 140 is also formed by the collar 130 and the cap 110. Thus, the stopper 101 can be easily formed, and the strength of the stopper 101 can be prevented from being reduced.

In the stopper 101, since the plurality of support portions 131 are separated from each other, members such as the coupling portion 132 are not provided between the adjacent support portions 131, and the width of the passage 140 is widened. Therefore, the flow resistance of the passage 140 can be reduced, and the fluid and dust flowing into the cap 110 from the rod hole 121 can be more reliably discharged to the outside of the cap 110.

Next, the operation of the buffer 1 will be described. Since the stopper 100 absorbs the impact only in cooperation with the impact pad 40 when the shock absorber 1 contracts, only the contraction operation of the shock absorber 1 will be described here.

When the shock absorber 1 contracts, the impact pad 40 hits the stopper 100 (see fig. 6). By contracting the impact pad 40, the shock generated when the shock absorber 1 contracts to the maximum extent is absorbed.

As the collision pad 40 contracts, air flows around the collision pad 40. At this time, the fluid and dust flow into the gap between the inner circumferential surface of the rod hole 112 of the plate-shaped portion 111 and the piston rod 30.

The fluid and dust flowing into the gap between the inner circumferential surface of the rod hole 112 of the plate-shaped portion 111 and the piston rod 30 are discharged to the outside of the cap 110 via the passage 140 (path shown by arrow in fig. 6). Thus, the pressure inside the cover 110 can be prevented from rising and dust can be prevented from accumulating inside the cover 110.

< embodiment 2 >

Next, a stopper 200 according to embodiment 2 of the present invention will be described with reference to fig. 7 to 9. The same components as those of embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

Fig. 7 is a cross-sectional view of the damper 2 having the stopper 200. Fig. 8 is a bottom view of the stopper 200. Fig. 9 is a sectional view taken along line IX-IX in fig. 8.

The stopper 200 includes a cap 110, a stopper 120, and a collar 230 provided at the inner side of the cap 110. The collar 230 has a plurality of support portions 131 and a plurality of coupling portions 232 for coupling adjacent support portions 131.

The coupling portion 232 is recessed in the axial direction of the piston rod 30 with respect to the support portion 131 and enters the rod hole 112. Specifically, as shown in fig. 9, the coupling portion 232 includes a base portion 232a formed continuously with the support portion 131 and an intermediate portion 232b formed continuously with the base portion 232 a. The base portion 232a is bent toward the stopper 120, and the intermediate portion 232b is in contact with the stopper 120.

In the state shown in fig. 9, the thickness of the coupling portion 232 is substantially equal to the thickness of the support portion 131, and the concave portion of the coupling portion 232 is formed by bending the base portion 232 a. Therefore, the coupling portion protrudes in the axial direction of the piston rod 30 with respect to the support portion 131.

The recess of the coupling portion 232 may not be formed by bending the base portion 232 a. For example, the concave portion may be formed by making the thickness of the coupling portion 232 thinner than the thickness of the support portion 131.

The stopper 200 has the following effects in addition to the effects of the stopper 100 according to embodiment 1.

Since the coupling portion 232 is recessed, as shown in fig. 7, a passage 240 is formed linearly along the end surface of the cylinder 10 (the surface of the oil seal 14) between the coupling portion 232 and the cylinder 10. Therefore, the flow resistance of the passage 240 can be reduced, and the fluid and dust flowing into the cap 110 from the rod hole 112 can be more reliably discharged to the outside of the cap 110. The same effect is also brought about in embodiment 3 described later.

The coupling portion 232 may not contact the stopper 120. The coupling portion 232 may contact the inner wall surface of the rod hole 112.

Since the operation of the buffer 2 is substantially the same as that of the buffer 1, the description thereof will be omitted here.

< embodiment 3 >

Next, a stopper 300 according to embodiment 3 of the present invention will be described with reference to fig. 10 and 11. The same components as those in embodiment 1 and embodiment 2 are denoted by the same reference numerals, and description thereof is omitted.

Fig. 10 is a sectional view of the bumper 3 having the stopper 300. Fig. 11 is a bottom view of the stopper 300.

The stopper 300 includes a cover 310, a stopper 120, and a collar 330 provided at the inner side of the cover 310. A circular rod hole 312 is formed in the plate-like portion 311 of the cover 310. The piston rod 30 can be inserted through the rod hole 312.

The coupling portion 332 of the collar 330 is located radially inward of the circular inner circumferential surface of the rod hole 312. The coupling portion 332 is formed recessed with respect to the support portion 131.

As shown in fig. 9, when the connection portion 232 is recessed so as to be accommodated in the opening 112c, the rising portion S of the concave portion is formed on the flow path cross section of the passage 240. The passage 240 narrows by an amount corresponding to the rising portion S.

In the present embodiment, since the coupling portion 332 is located radially inward of the circular inner circumferential surface of the rod hole 312, there is no rising portion of the concave portion in the flow path cross section of the passage 340, and the width of the passage 340 is widened. Therefore, the flow resistance of the passage 340 can be reduced, and the fluid and dust flowing into the cover 310 from the rod hole 312 can be more reliably discharged to the outside of the cover.

The coupling portion 332 of the collar 330 is formed in a ring shape having a 3 rd rod hole 333. The piston rod 30 can be inserted through the 3 rd rod hole 333. The plurality of support portions 131 are arranged on the outer periphery of the annular coupling portion 332. The collar 330 is fixed to the cover 310 by the engagement between the coupling portion 332 and the inner peripheral surface of the rod hole 312 of the plate portion 311.

The coupling portion 332 is disposed in the rod hole 312 of the plate portion 311. Therefore, the coupling portion 332 is not covered by the cover 310. Therefore, when the collar 330 is fixed to the cover 310, the coupling portion 332 can be seen from the outside of the cover 310, and the coupling portion 332 can be easily joined to the inner peripheral surface of the rod hole 312 of the plate-like portion 311.

The coupling portion 332 may or may not contact the stopper 120.

The stopper 300 has the following effects in addition to the effects of the stopper 100 and 200 according to embodiment 1 and embodiment 2.

Since the coupling portion 332 is not covered with the cover 310, the coupling portion 332 can be seen from the outside of the cover 310 when the collar 330 is fixed to the cover 310, and the coupling portion 332 can be easily joined to the inner peripheral surface of the rod hole 312 of the plate-shaped portion 311.

Since the operation of the buffer 3 is substantially the same as that of the buffer 1, the description thereof will be omitted here.

Hereinafter, the structure, operation and effects of the embodiments of the present invention will be described in summary.

In the present embodiment, the stoppers 100, 101, 200, and 300 absorb the impact generated when the cushions 1, 2, and 3 contract to the maximum extent in cooperation with the impact pad 40. The stopper 100, 101, 200, 300 includes: a cap 110, 310 having a plate-shaped portion 111, 311 and a cylindrical portion 115, the plate-shaped portion 111, 311 having a rod hole 112, 312 through which the piston rod 30 of the shock absorber 1, 2, 3 can pass, the cylindrical portion 115 being capable of receiving a part of the cylinder 10 of the shock absorber 1, 2, 3; a stopper 120 provided on the plate-like portions 111 and 311 and receiving the collision pad 40; and collars 130, 230, 330 provided on the plate-like portions 111, 311 so as to face the cylinder 10.

In this configuration, since the collars 130, 230, 330 are provided on the plate-shaped portions 111, 311 so as to face the cylinder 10, it is not necessary to form the caps 110, 310 into complicated shapes. Therefore, the stoppers 100, 101, 200, and 300 can be easily manufactured and have sufficient strength.

In the present embodiment, the collar 130, 230, 330 of the stopper 100, 101, 200, 300 has a plurality of support portions 131, and the plurality of support portions 131 are radially arranged on the plate-shaped portions 111, 311 to support the plate-shaped portions 111, 311, and the cap 110, 310 and the collar 130, 230, 330 form passages 140, 240, 340 that communicate the rod holes 112, 312 with the outside of the cap 110, 310 via the inside of the cylindrical portion 115, and the passages 140, 240, 340 are formed between the adjacent support portions 131.

In this configuration, since the passages 140, 240, and 340 are formed between the adjacent support portions 131, the passage forming portions of the plate-shaped portions 111 and 311 are supported by the support portions 131 on both sides and are not easily deformed. Therefore, the cross-sectional shape of the passages 140, 240, 340 can be prevented from being deformed, and the fluid and dust flowing into the caps 110, 310 from the rod holes 112, 312 can be more reliably discharged to the outside of the caps 110, 310.

In the present embodiment, the collars 130, 230, 330 of the stoppers 100, 200, 300 further include coupling portions 132, 232, 332 for coupling the adjacent support portions 131.

In this configuration, since the coupling portions 132, 232, and 332 couple the adjacent support portions 131, the plurality of support portions 131 are integrated by the coupling portions 132, 232, and 332. Thus, the collars 130, 230, 330 can be easily handled.

In the present embodiment, the rod hole 112 of the stopper 100 has the opening 112c, and the coupling portion 132 is located radially inward of the inner peripheral surface of the opening 112c and is formed in a planar shape along the support portion 131.

In this configuration, since the coupling portion 132 is formed in a planar shape along the support portion 131, the collar 130 is simplified. Further, it is not necessary to form the collar 130 in consideration of the gap between the coupling portion 132 and the stopper 120 so as to prevent the coupling portion 132 and the stopper 120 from contacting each other, and the collar 130 can be easily formed.

In the present embodiment, the stopper 200 has the rod hole 112 having the opening 112c, and the coupling portion 232 is formed recessed from the support portion 131 at a position radially inward of the inner peripheral surface of the opening 112 c.

In this configuration, since the coupling portion 232 is recessed with respect to the support portion 131, the passage 240 is linearly formed along the end surface of the cylinder 10. Therefore, the flow resistance of the passage 240 can be reduced, and the fluid and dust flowing into the cap 110 from the rod hole 112 can be more reliably discharged to the outside of the cap 110.

In the present embodiment, the stopper 300 has a circular rod hole 312, and the coupling portion 332 is formed recessed from the support portion 131 at a position radially inward of the inner circumferential surface of the circular rod hole 312.

In this configuration, since the coupling portion 332 is located radially inward of the circular inner circumferential surface of the rod hole 312, there is no rising portion of the concave portion in the flow path cross section of the passage 340, and the width of the passage 340 is widened. Therefore, the flow resistance of the passage 340 can be reduced, and the fluid and dust flowing into the cover 310 from the rod hole 312 can be more reliably discharged to the outside of the cover 310.

In the present embodiment, the coupling portion 332 of the stopper 300 is formed in an annular shape and is disposed in the rod hole 312 of the plate portion 311.

In this configuration, since the annular coupling portion 332 is disposed in the rod hole 312, the coupling portion 332 is not covered with the cover 310. Therefore, when the collar 330 is fixed to the cover 310, the coupling portion 332 can be viewed from the outside of the cover 310, and the coupling portion 332 can be easily joined to the inner wall surface of the rod hole 312.

In the present embodiment, the plurality of support portions 131 are separated from each other in the stopper 101.

In this configuration, since the plurality of support portions 131 are separated from each other, members such as the coupling portions 132 are not provided between the adjacent support portions 131, and the width of the passage 140 is widened. Therefore, the flow resistance of the passage 140 can be reduced, and the fluid and dust flowing into the cap 110 from the rod hole 121 can be more reliably discharged to the outside of the cap 110.

In the present embodiment, the stopper 100, 101, 200, 300 is characterized in that the inner circumferential surface of the stopper 120 is located radially inward of the inner circumferential surfaces of the rod holes 112, 312 of the plate-shaped portions 111, 311.

In this configuration, since the inner peripheral surface of the stopper 120 is located inward of the inner peripheral surfaces of the rod holes 112 and 312 of the plate-shaped portions 111 and 311, the clearance between the stopper 120 and the piston rod 30 is smaller than the clearance between the inner peripheral surfaces of the rod holes 112 and 312 and the piston rod 30. Therefore, regardless of the size of the rod holes 112 and 312, the collision pad 40 is less likely to enter the gap between the stopper 120 and the piston rod 30, and damage to the collision pad 40 can be prevented.

In the present embodiment, the buffers 1, 2, and 3 are characterized by including: the aforementioned stoppers 100, 101, 200, 300; and a piston rod 30 inserted through the rod holes 112 and 312, wherein the passages 140, 240 and 340 have a flow path cross section larger than a flow path cross section of a gap between the stopper 120 and the piston rod 30.

In this structure, since the passage 140, 240, 340 has a larger flow passage section than the gap between the stopper 120 and the piston rod 30, the fluid and dust flowing into the passage 140, 240, 340 from the gap are less likely to stagnate within the passage 140, 240, 340. Therefore, the fluid and dust flowing into the cover 110, 310 from the rod hole 112, 312 can be more reliably discharged to the outside of the cover 110, 310.

While the embodiments of the present invention have been described above, the above embodiments are merely examples of applications of the present invention, and the scope of the present invention is not limited to the specific configurations of the above embodiments.

This application claims priority based on application laid out in the patent office of this country on 2015, 11, 20, 2015-227816, the entire contents of which are incorporated by reference into this specification.