JP2021127818A - Cylinder device - Google Patents

Abstract

To provide a cylinder device whose appearance can be further restrained from deteriorating.SOLUTION: A cylinder device comprises: a cylinder 15 filled with working liquid; a rod 31 extending from an opening part 19 of the cylinder 15; a seal member 23 closing a gap between the cylinder 15 and the rod 31 at the position of the opening part 19, and bringing the rod 31 in sliding contact; and a cap 3 covering the opening part 19 of the cylinder 15. The cap 3 comprises: a cap body 81 comprising a cylindrical part 85 fitted to an outer peripheral part of the cylinder 15, and a cover part 86 extending inward from the cylindrical part 85, covering the opening part 19, and having a perforated disk shape; and a ring-shaped member 82 interposed in a clearance between the cylindrical part 85 and the cylinder 15.SELECTED DRAWING: Figure 2

Description

The present invention relates to a cylinder device.

Some cylinder devices have a sealing member between the cylinder and the rod. In such a cylinder device, when the rod extends from the cylinder, the working liquid in the cylinder adheres to the rod in a film form and goes out of the seal member, and the rod reciprocates repeatedly. As a result, the working liquid adheres to the outside of the cylinder device in a very small amount. If the working liquid adheres to the outside of the cylinder device in this way, the appearance is deteriorated. Therefore, an absorbing member for absorbing such a working liquid is provided (see, for example, Patent Documents 1 and 2).

JP-A-2007-113624 Jikkenhei 2-87145 Gazette

Cylinder devices are required to further suppress deterioration in appearance.

Therefore, an object of the present invention is to provide a cylinder device capable of further suppressing deterioration of appearance.

In order to achieve the above object, in the present invention, the cap covering the opening of the cylinder has a tubular portion fitted to the outer peripheral portion of the cylinder and the opening extending inward from the tubular portion. It is configured to include a cap body having a perforated disk-shaped cover portion for covering the cylinder, and a ring-shaped member interposed in a gap between the tubular portion and the cylinder.

According to the present invention, it is possible to further suppress the deterioration of the appearance.

It is sectional drawing which shows the cylinder apparatus of embodiment which concerns on this invention. It is sectional drawing which shows the main part of the cylinder apparatus of embodiment which concerns on this invention, and is the sectional view of the cap which made the cross section by line II-II shown in FIG. It is a front view which shows the cap of the cylinder device of embodiment which concerns on this invention. It is a bottom view which shows the cap of the cylinder device of embodiment which concerns on this invention.

The cylinder device of the embodiment according to the present invention will be described below with reference to the drawings. The cylinder device 1 of the first embodiment shown in FIG. 1 is a shock absorber used in a suspension device of a vehicle such as an automobile or a railroad vehicle. The cylinder device 1 has a cylinder device main body 2 and a cap 3.

First, the cylinder device main body 2 will be described. The cylinder device main body 2 is a bottomed cylinder that forms a reservoir chamber 13 between a cylindrical metal inner cylinder 12 and an inner cylinder 12 having a diameter larger than that of the inner cylinder 12 and provided on the outer peripheral side of the inner cylinder 12. It has a metal outer cylinder 14 in the shape of a metal. That is, the cylinder device 1 is a double-cylinder type shock absorber in which the outer cylinder 14 and the inner cylinder 12 form the cylinder 15. In the cylinder 15, the working liquid is sealed in the inner cylinder 12, and the working liquid and the working gas are sealed in the reservoir chamber 13 between the outer cylinder 14 and the inner cylinder 12. The working liquid is specifically an oil liquid.

The outer cylinder 14 includes a cylindrical body portion 17 and a bottom portion 18 that closes one end side of the body portion 17 in the axial direction. The inner cylinder 12 has a cylindrical shape. The inner cylinder 12 is engaged with the bottom portion 18 of the outer cylinder 14 via an annular base member 20 attached to one end in the axial direction thereof. Further, the inner cylinder 12 is engaged with the opening 19 side opposite to the bottom 18 of the body 17 of the outer cylinder 14 via an annular rod guide 21 attached to the other end in the axial direction. There is.

The base member 20 is placed on the bottom 18 of the outer cylinder 14 in a state of being fitted and fixed to the inner cylinder 12, and at that time, the base member 20 is positioned in the radial direction. As a result, the base member 20 and the inner cylinder 12 are arranged coaxially with the outer cylinder 14. The rod guide 21 is fitted to the inner cylinder 12 and the body portion 17 of the outer cylinder 14, so that the other end portion of the inner cylinder 12 in the axial direction is arranged coaxially with the outer cylinder 14.

An annular sealing member 23 is arranged on the opposite side of the rod guide 21 from the bottom portion 18, and the sealing member 23 is also fitted to the inner peripheral portion of the body portion 17 on the opening 19 side. There is. Since the opening 19 of the outer cylinder 14 is outside the inner cylinder 12 in the axial direction, it is also an opening of the cylinder 15. A locking portion 24 is formed at the end of the outer cylinder 14 on the opening 19 side by being bent inward in the radial direction, and the outer portion of the seal member 23 in the radial direction is the locking portion 24. Is sandwiched between the rod guide 21 and the rod guide 21.

A piston 25 is slidably fitted in the inner cylinder 12. The piston 25 defines a first chamber 28 and a second chamber 29 in the inner cylinder 12. The first chamber 28 is provided between the piston 25 in the inner cylinder 12 and the rod guide 21, and the second chamber 29 is provided between the piston 25 in the inner cylinder 12 and the base member 20. The second chamber 29 in the inner cylinder 12 is defined as the reservoir chamber 13 by the base member 20.

A metal rod-shaped rod 31 is connected to the piston 25 by a nut 32. The rod 31 has a columnar main shaft portion 33 having a constant outer diameter, and extends outward from the opening 19 of the cylinder 15 through the rod guide 21 and the seal member 23 in the main shaft portion 33. The rod 31 is slidably inserted inside the rod guide 21 and the seal member 23 at the main shaft portion 33 thereof. One end of the rod 31 is arranged inside the outer cylinder 14 and the inner cylinder 12, and the other end side is arranged outside the outer cylinder 14 and the inner cylinder 12. The rod 31 moves in the axial direction integrally with the piston 25.

The seal member 23 through which the main shaft portion 33 of the rod 31 is inserted closes between the outer cylinder 14 and the rod 31 at the position of the opening 19 of the cylinder 15, and the working liquid in the inner cylinder 12 and the inside of the reservoir chamber 13 are closed. Regulate the leakage of working gas and working liquid to the outside. Further, the seal member 23 slides the main shaft portion 33 into contact with the rod 31 when the rod 31 moves in the axial direction.

The piston 25 is formed with a passage 34 and a passage 35 penetrating in the axial direction. The passages 34 and 35 allow the first chamber 28 and the second chamber 29 to communicate with each other. The piston 25 is provided with an annular disc valve 36 that can close the passage 34 by contacting the piston 25 on the side of the opening 19 in the axial direction. Further, the piston 25 is provided with an annular disc valve 37 that can close the passage 35 by contacting the piston 25 on the bottom 18 side in the axial direction.

In the disc valve 36, the rod 31 moves to the contraction side that increases the amount of entry into the inner cylinder 12 and the outer cylinder 14, the piston 25 moves in the direction of narrowing the second chamber 29, and the pressure in the second chamber 29 becomes the first. When the pressure is higher than the pressure of the chamber 28 by a predetermined value or more, the passage 34 is opened, and at that time, a damping force is generated. At least one of the piston 25 and the disc valve 36 has a fixed orifice (not shown) that allows the first chamber 28 and the second chamber 29 to communicate with each other through the passage 34 even when the disc valve 36 is in the most closed passage 34. It is formed.

In the disc valve 37, the rod 31 moves to the extension side that increases the amount of protrusion from the inner cylinder 12 and the outer cylinder 14, the piston 25 moves in the direction of narrowing the first chamber 28, and the pressure of the first chamber 28 becomes the second chamber. When the pressure is higher than the pressure of 29 by a predetermined value or more, the passage 35 is opened, and a damping force is generated at that time. At least one of the piston 25 and the disc valve 37 has a fixed orifice (not shown) that allows the first chamber 28 and the second chamber 29 to communicate with each other through the passage 35 even when the disc valve 37 most closes the passage 35. It is formed.

The base member 20 is formed with a passage 41 and a passage 42 penetrating in the axial direction. The passages 41 and 42 can communicate with the second chamber 29 and the reservoir chamber 13. An annular disc valve 43 capable of closing the passage 41 by abutting against the base member 20 is arranged on the base member 20 on the side of the bottom 18 in the axial direction, and is located on the side opposite to the bottom 18 in the axial direction. An annular disc valve 44 capable of closing the passage 42 by contacting the base member 20 is arranged.

The disc valve 43 is a check valve that allows the flow of the working liquid from the second chamber 29 to the reservoir chamber 13 side through the passage 41 and regulates the flow of the working liquid through the passage 41 in the opposite direction. The disc valve 43 opens the passage 41 when the rod 31 moves to the contraction side and the pressure in the second chamber 29 becomes higher than the pressure in the reservoir chamber 13 by a predetermined value or more, and the damping force is generated at that time. It is a valve.

The disc valve 44 is a check valve that allows the flow of the working liquid from the reservoir chamber 13 to the second chamber 29 side through the passage 42 and regulates the flow of the working liquid through the passage 42 in the opposite direction. The disc valve 44 opens the passage 42 when the rod 31 moves to the extension side, the piston 25 moves to the first chamber 28 side, and the pressure in the second chamber 29 drops below the pressure in the reservoir chamber 13. It is a suction valve that allows the working liquid to flow from the reservoir chamber 13 into the second chamber 29 without substantially generating a damping force.

A tubular mounting eye 46 is fixed to the outside of the bottom 18 of the outer cylinder 14. In the cylinder device main body 2, with the cap 3 attached, the portion of the rod 31 outside the cap 3 and the attachment eye 46 are attached to the relative moving portion to be attached. In the cylinder device main body 2, the piston 25 slides axially in the inner cylinder 12 of the cylinder 15 integrally with the rod 31 due to the relative movement of the attachment target portion to change the volumes of the first chamber 28 and the second chamber 29. At that time, a damping force is generated by the flow resistance of the working liquid generated in the piston 25 and the base member 20. In the cylinder device main body 2, for example, the rod 31 is arranged at the upper position and connected to the vehicle body side, and the mounting eye 46 is arranged at the lower position and connected to the wheel side of the vehicle so that the wheels move with respect to the vehicle body. To generate damping force.

As shown in FIG. 2, the rod guide 21 has a substantially stepped annular shape, and a large-diameter portion 51 having a cylindrical outer peripheral surface on one side in the axial direction is formed, and the outer peripheral surface is formed on the other side in the axial direction. A small diameter portion 52 formed of a cylindrical surface having a diameter smaller than that of the outer peripheral surface of the large diameter portion 51 is formed. The large diameter portion 51 and the small diameter portion 52 are formed coaxially, and the rod guide 21 fits on the inner peripheral surface of the body portion 17 of the outer cylinder 14 in the large diameter portion 51, and the inner cylinder 12 in the small diameter portion 52. Fits on the inner peripheral surface of.

An annular convex portion 55 projecting in the axial direction is formed at the end of the rod guide 21 on the large diameter portion 51 side in the axial direction. The annular convex portion 55 is formed with a communication hole 56 that penetrates the rod guide 21 along the axial direction at its radial inner position. The communication hole 56 opens in the reservoir chamber 13 between the outer cylinder 14 and the inner cylinder 12 on the side opposite to the annular convex portion 55 in the axial direction of the rod guide 21.

The seal member 23 is an integrally molded seal member main body 63 in which a metal perforated disc-shaped annular member 62 is embedded in a synthetic rubber sealing material 61, a metal annular spring 64, and a metal. It has an annular spring 65 and the like. The annular member 62 is for maintaining the shape of the sealing material 61, and gives the sealing member main body 63 strength for fixing to the target portion. In the seal member main body 63, the position of the annular member 62 in the radial direction is sandwiched between the annular convex portion 55 of the rod guide 21 and the locking portion 24 of the outer cylinder 14 and supported on one end side of the cylinder 15.

The sealing material 61 has a dust strip portion 71, an oil lip portion 72, a sealing ring portion 73, and a check lip portion 74.

The dust strip portion 71 extends in a tubular shape from the inner peripheral surface side of the annular member 62 to one side in the axial direction. The dust strip portion 71 projects outward from the outer cylinder 14, that is, outward from the cylinder 15 through the opening 19 of the outer cylinder 14. The oil lip portion 72 extends from the inner peripheral surface side of the annular member 62 to the other side in the axial direction in a tubular shape. The seal member main body 63 is inserted into the oil lip portion 72 and the dust strip portion 71 so that the main shaft portion 33 of the rod 31 can be slidably inserted, and the dust strip portion 71 and the oil lip portion 72 are inserted into the main shaft portion of the rod 31. Seal the gap with the portion 33.

The seal ring portion 73 projects in an annular shape from the outer peripheral surface side of the annular member 62 to the same side as the oil lip portion 72 in the axial direction. The seal ring portion 73 simultaneously contacts the annular convex portion 55 of the rod guide 21 and the body portion 17 of the outer cylinder 14 to seal the gap between the outer cylinder 14 and the rod guide 21.

The check lip portion 74 projects from an intermediate position in the radial direction of the annular member 62 on the same side as the oil lip portion 72 in the axial direction in an annular tubular shape. The check lip portion 74 is in contact with the inner portion in the radial direction of the annular convex portion 55 of the rod guide 21, and the working fluid leaking from the gap between the rod guide 21 and the main shaft portion 33 of the rod 31 is communicated with the hole 56. It functions as a check valve that regulates the flow of the working fluid in the opposite direction while flowing to the reservoir chamber 13 via the above. The spring 64 is attached to the outer peripheral portion of the dust strip portion 71 of the seal member main body 63, and the spring 65 is attached to the outer peripheral portion of the oil lip portion 72.

In the seal member 23 composed of the seal member main body 63 and the springs 64 and 65, the dust strip portion 71 and the spring 64 project outward from the outer cylinder 14 through the opening 19 of the outer cylinder 14, that is, outward from the cylinder 15. ..

The cap 3 is attached to the cylinder device main body 2 having the above configuration. The cap 3 is attached to the cylinder 15 so as to cover the opening 19 side thereof to protect the cylinder device main body 2. The cap 3 has a cap main body 81 and an O-ring 82 (ring-shaped member).

The cap body 81 is an integrally molded product of synthetic resin, and has a cylindrical tubular portion 85 fitted to the outer peripheral portion of the body 17 of the outer cylinder 14 and a radial direction from one end of the tubular portion 85 in the axial direction. It has a perforated disk-shaped cover portion 86 that extends inward and covers the opening 19 of the cylinder 15 and the seal member 23, and a plurality of ribs 87 that bulge outward in the axial direction from the cover portion 86. .. The O-ring 82 is made of synthetic rubber, and fills the gap between the tubular portion 85 of the cap body 81 and the body portion 17 of the outer cylinder 14 over the entire circumference to seal the O-ring 82.

As shown in FIG. 3, the tubular portion 85 is formed with an annular flange portion 99 on the outer peripheral portion on the side where the cover portion 86 in the axial direction is arranged. The flange portion 99 projects radially outward from the outer peripheral surface 140 formed of the cylindrical surface of the portion of the tubular portion 85 excluding the flange portion 99. The outer peripheral surface 141 of the tubular portion 85 has an outer peripheral surface 140 formed of a cylindrical surface, and at the position of the flange portion 99, the cylindrical surface 142 and the R chamfer on the rib 87 side in the axial direction with respect to the cylindrical surface 142. It has 143 and a tapered surface 144 on the side opposite to the rib 87 in the axial direction with respect to the cylindrical surface 142. The diameter of the R chamfer 143 becomes smaller as the distance from the cylindrical surface 142 in the axial direction increases. The tapered surface 144 also has a smaller diameter as the distance from the cylindrical surface 142 in the axial direction increases.

As shown in FIG. 4, the tubular portion 85 of the cap body 81 has an inner peripheral surface 91 formed of a cylindrical surface and a plurality of fitting protrusions protruding inward in the radial direction from the inner peripheral surface 91, specifically, six fitting protrusions. It has a part 92 and. The fitting convex portions 92 are arranged at equidistant positions on the inner peripheral surface 91 in the circumferential direction. As shown in FIG. 2, the tubular portion 85 is formed with an annular seal arrangement groove 95 that is recessed radially outward from the inner peripheral surface 91. The seal arrangement groove 95 has an annular shape centered on the central axis of the inner peripheral surface 91, and all of the plurality of fitting convex portions 92 also cross the inner peripheral surface 91 in the circumferential direction. An O-ring 82 is arranged in the seal arrangement groove 95, and the seal arrangement groove 95 positions and holds the O-ring 82 with respect to the cap body 81.

The tubular portion 85 is formed with an annular recess 98 that is radially outwardly recessed from the inner peripheral surface 91 on the cover portion 86 side in the axial direction with respect to the seal arrangement groove 95. In other words, the tubular portion 85 is provided with a recess 98 recessed radially outward from the inner peripheral surface 91 on the cover portion 86 side of the seal arrangement groove 95 where the O-ring 82 is provided. The recess 98 has an annular shape centered on the central axis of the inner peripheral surface 91, and all of the plurality of fitting convex portions 92 also cross the inner peripheral surface 91 in the circumferential direction.

A hole 101 penetrating in the axial direction is formed in the cover portion 86 at the center in the radial direction. In the cover portion 86, the inner peripheral surface 102 forming the hole 101 is composed of a tapered surface portion 103 on the side of the seal arrangement groove 95 in the axial direction and a cylindrical surface portion 104 on the side opposite to the seal arrangement groove 95 in the axial direction. ing. The tapered surface portion 103 has a larger diameter as it approaches the seal arrangement groove 95. The plurality of ribs 87 are formed radially around the holes 101 in the cover portion 86, and are provided at equal intervals in the circumferential direction of the cover portion 86.

The cover portion 86 has a flat surface in which the end surface 111 on the side of the seal arrangement groove 95 in the axial direction extends in the direction orthogonal to the axis of the tubular portion 85. The cover portion 86 has a cylindrical wall surface 112 extending from the inner peripheral edge portion of the end surface 111 to the side opposite to the seal arrangement groove 95 in the axial direction, and an end edge of the wall surface 112 on the side opposite to the seal arrangement groove 95. It has a bottom surface 113 extending inward in the radial direction from the portion. The bottom surface 113 is also a flat surface extending in the direction orthogonal to the axis of the tubular portion 85. The end surface 111, the wall surface 112, and the bottom surface 113 form an inner surface 114 on the side of the seal arrangement groove 95 in the axial direction of the cover portion 86.

The cap body 81 is formed with a communication groove 121 that is continuous with the inner surface 114 on the side of the seal arrangement groove 95 in the axial direction of the cover portion 86 and the inner peripheral surface 91 of the tubular portion 85 and communicates with the recess 98. That is, the communication groove 121 opens at one end on the wall surface 112 of the cover portion 86, opens at the end surface 111 and extends in the radial direction of the cover portion 86, and then opens at the inner peripheral surface 91 of the tubular portion 85 to form a cylinder. The shape portion 85 extends in the axial direction, and the other end opens in the recess 98. As shown in FIG. 4, the communication grooves 121 are formed at a plurality of equidistant locations, specifically, six locations in the circumferential direction of the cover portion 86. The communication groove 121 is arranged one by one at the central position between the fitting convex portion 92 and the fitting convex portion 92 adjacent to each other in the circumferential direction of the tubular portion 85.

As shown in FIG. 2, one end of the cap body 81 opens to the tapered surface 103 of the inner peripheral surface 102 of the cover 86, and the other end is a cylinder of the flange 99 of the outer peripheral surface 141 of the tubular portion 85. A passage 126 that opens to the surface 142 is formed. The passage 126 extends linearly in the radial direction of the cover portion 86 and the tubular portion 85. In other words, the passage 126 extends so as to be orthogonal to the central axis of the cover portion 86 and the tubular portion 85. The passage 126 has the positions of the cover portion 86 and the tubular portion 85 in the circumferential direction coincided with the fitting convex portion 92, and is formed in the cap main body 81 at the same six locations as the fitting convex portion 92.

An O-ring 82 is fitted into the seal arrangement groove 95 of the cap body 81 to form the cap 3. Before the cap 3 is attached to the cylinder device main body 2, as shown in FIG. 4, the O-ring 82 is radially inward from the inner peripheral surface 91 of the tubular portion 85 over all the fitting convex portions 92. It has spread.

As shown in FIG. 2, the cap body 81 is fitted by pressing the cap body 81 into the opening 19 side of the cylinder device body 2 at the tubular portion 85 while passing the rod 31 through the hole 101. At that time, the cap body 81 is pressed against the outer peripheral portion of the body portion 17 of the outer cylinder 14 at the plurality of fitting convex portions 92 of the tubular portion 85 and fixed to the outer cylinder 14. Further, the cap body 81 brings the end surface 111 of the cover portion 86 into contact with the locking portion 24 of the outer cylinder 14.

In this state, the cover portion 86 is in a state of covering the opening 19 of the cylinder 15 and the seal member 23. Further, in this state, the O-ring 82 presses against the bottom surface of the seal arrangement groove 95 and the outer peripheral portion of the body portion 17 of the outer cylinder 14 to fill the gap between the body portion 17 and the tubular portion 85 and seal the seal. It will be in a state of doing. Further, in this state, the tubular portion 85 has an annular recess 98 recessed radially outward from the inner peripheral surface 91 on the cover portion 86 side of the seal arrangement groove 95 at the position where the O-ring 82 is provided. It is provided. Further, in this state, the cap body 81 is formed with a communication groove 121 that is continuous with the inner surface 114 of the cover portion 86 on the opening 19 side and the inner peripheral surface 91 of the tubular portion 85 and communicates with the recess 98. There is.

In the cylinder device 1 configured by attaching the cap 3 to the cylinder device main body 2 in this way, the rod 31 is in a posture in which the portion of the rod 31 protruding from the cylinder 15 is on the upper side and the mounting eye 46 is on the lower side. It will be assembled on the vehicle body side and on the wheel side of the mounting eye 46. At that time, the bellows tubular bump rubber 131 is arranged by inserting the rod 31 inside from the vehicle body, and the cap 3 is inserted into the outer shell 132 with a radial gap. .. The bellows tubular bump rubber 131 surrounds the hole 101 and abuts on the plurality of ribs 87 of the cap 3. The cap 3 is a bumper cap attached to the cylinder 15 in order to protect the seal member 23 from the bump rubber 131 in the cylinder device 1.

The above-mentioned Patent Documents 1 and 2 describe a cylinder device having a sealing member between the cylinder and the rod. The sealing member maintains the slidability with the rod, in other words, for lubrication, when the rod moves from the cylinder in the extending direction, the working liquid in the cylinder adhering to the rod is applied to the sliding contact surface with the rod. It is designed to be attached. Therefore, the sealing member does not completely scrape off the working liquid adhering to the rod, and the working liquid comes out of the sealing member in a film-like state adhering to the rod.

When the rod moves in the contraction direction, a part of the working liquid that adheres to the rod in a film form and goes out of the seal member is scraped off by the seal member and remains on the outside of the seal member. I will end up. By repeating such a process, a very small amount of working liquid adheres to the outside of the cylinder device. If the working liquid adheres to the outside of the cylinder device in this way, the appearance is deteriorated. For this reason, Patent Documents 1 and 2 provide an absorbing member that absorbs such a working liquid. However, it may not be possible to say that the effect of suppressing the deterioration of the appearance is sufficient only by providing the absorbing member as described above.

On the other hand, in the cylinder device 1 of the embodiment, the cap 3 covering the opening 19 of the cylinder 15 extends inward from the cylindrical portion 85 fitted to the outer peripheral portion of the cylinder 15 and the tubular portion 85. It is provided with a cap body 81 having a perforated disk-shaped cover portion 86 that is exposed and covers the opening 19, and an O-ring 82 that fills and seals a gap between the tubular portion 85 and the cylinder 15. Therefore, the working liquid and the working liquid remaining on the outside of the cylinder device main body 2 are repeatedly scraped off by the sealing member 23 and remaining on the outside of the sealing member 23. The dust containing the above can be held between the portion of the tubular portion 85 on the cover portion 86 side of the O-ring 82 and the cover portion 86 and the cylinder device main body 2. Moreover, since the O-ring 82 is provided between the tubular portion 85 and the cylinder 15 of the cap 3 that covers the opening 19 of the cylinder 15 and is fitted to the outer peripheral portion of the cylinder 15, the working liquid and the working liquid can be collected. The holding capacity of the contained dust can be expanded. Therefore, it is possible to further suppress the deterioration of the appearance.

In addition, since the cap 3 necessary for protecting the opening 19 side of the cylinder 15 and the seal member 23 is used, it is possible to suppress an increase in cost.

Further, since the tubular portion 85 of the cap body 81 is provided with a recess 98 recessed radially outward from the inner peripheral surface 91 on the cover portion 86 side of the position where the O-ring 82 is provided, the working liquid And the holding capacity of dust containing working liquid can be expanded.

Further, since the cap body 81 is formed with a communication groove 121 that communicates with the recess 98 continuously on the inner surface 114 of the cover portion 86 on the opening 19 side and the inner peripheral surface 91 of the tubular portion 85, it operates. Dust containing a liquid and a working liquid can be smoothly flowed into the recess 98 through the communication groove 121.

Further, since the cap body 81 is formed with a passage 126 having one end opened to the inner peripheral surface 102 of the cover portion 86 and the other end opening to the outer peripheral surface 141 of the tubular portion 85, the cap main body 81 is formed by the O-ring 82. Even if the space between the 81 and the outer peripheral portion of the cylinder 15 is sealed, the air in the bump rubber 131 can be exhausted to the outside of the cylinder device 1 through the passage 126 when the bump rubber 131 is contracted. That is, the bump rubber 131 has a tubular shape and comes into contact with the plurality of ribs 87 and the cover portion 86 of the cap 3 so as to surround the holes 101, but the gap between the cap 3 and the cylinder device main body 2 is O-ringed. Since it is blocked by 82, it becomes difficult to exhaust the air discharged from the bump rubber 131 to the outside without the passage 126 at the time of contraction. By providing the passage 126, the air in the bump rubber 131 can be smoothly exhausted to the outside of the cylinder device 1 via the passage 126.

In addition, since the cap body 81 is formed with a passage 126 in the cover portion 86 which is above the O-ring 82, the recess 98, and the communication groove 121 and covers the seal member 23, the air flow path and the seal member The working liquid flowing along the 23 and the flow path of the dust containing the working liquid can be separated. That is, since the working liquid and the dust containing the working liquid flowing along the sealing member 23 move downward by their own weight, they are well collected in the lower communication groove 121 and the recess 98, while the air is sealed. It can flow separately from the working liquid in the passage 126 above the member 23.

Further, since the tubular portion 85 of the cap body 81 is formed with a flange portion 99 on the outer peripheral portion on the side where the cover portion 86 is arranged, the gap between the outer shell 132 and the cylinder can be narrowed. It is possible to prevent dust from entering the cap 3 through the gap with the device 1. In particular, since the cap body 81 including the flange portion 99 is formed of a synthetic resin material having a high degree of freedom in shape and high molding accuracy, the gap with the outer shell 132 can be further narrowed. The durability of the sealing member 23 can be improved by suppressing the entry of dust into the cap 3 by the flange portion 99.

In addition, since the flange portion 99 is provided on the outer peripheral portion of the tubular portion 85 of the cap body 81 on the cover portion 86 side, the lower end portion of the outer shell 132 and the cylinder device are provided while narrowing the gap between the cylinder device 1 and the outer shell 132. The gap between the outer cylinder 14 and the outer cylinder 14 of 1 can be enlarged to suppress rubbing. Even if the outer shell 132 and the cylinder device 1 come into contact with each other, the cap main body 81 comes into contact with the outer shell 132 at the flange portion 99, so that the lower end portion of the outer shell 132 and the outer cylinder 14 of the cylinder device main body 2 come into contact with each other. Rubbing can be suppressed, and damage to the coating applied to the outer cylinder 14 can be suppressed.

Further, since the R chamfer 143 is formed at the end of the flange portion 99 on the rib 87 side, even if the cap body 81 may come into contact with the outer shell 132, the contact with the outer shell 132 in the R chamfer 143 causes the cap body 81 to come into contact with the outer shell 132. The contact becomes smooth and the generation of abnormal noise can be suppressed.

Since the tubular portion 85 of the cap 3 is provided with an O-ring 82 which is an elastic body so as to seal the gap with the cylinder 15, the O-ring 82 is provided in addition to the frictional force of the plurality of fitting convex portions 92. The frictional force can also prevent the cap 3 from coming off the cylinder 15.

Even if the tubular portion 85 of the cap body 81 is not provided with the seal arrangement groove 95, the seal arrangement groove is provided on the outer peripheral portion of the cylinder 15 so that the O-ring 82 is positioned and held on the cylinder 15 side. good.

Further, the ring-shaped member that fills the gap between the tubular portion 85 of the cap body 81 and the cylinder 15 is not limited to the O-ring 82 having a circular cross section, and other seal rings such as a square ring having a rectangular cross section may be used. Not only can it be adopted, but it is also possible to adopt a ring-shaped liquid absorbing member made of a working liquid and a perforated chamber material that absorbs and holds dust containing the working liquid. However, the seal ring has a higher effect of suppressing deterioration in appearance than the liquid absorbing member.

In the first aspect of the above-described embodiment, the cylinder in which the working liquid is sealed, the rod extending from the opening of the cylinder, and the cylinder and the rod are closed at the position of the opening. A cylinder device including a sealing member for sliding contact with the rod and a cap for covering the opening of the cylinder, wherein the cap has a tubular portion fitted to an outer peripheral portion of the cylinder and the above-mentioned. A cap body having a perforated disk-shaped cover portion extending inward from the tubular portion and covering the opening, and a ring-shaped member interposed in a gap between the tubular portion and the cylinder. To be equipped. This makes it possible to further suppress the deterioration of the appearance.

In the second aspect, in the first aspect, the tubular portion is provided with a recess recessed radially outward from the inner peripheral surface on the cover portion side with respect to the position where the ring-shaped member is provided. ing.

In the third aspect, in the second aspect, the cap body has a communication groove that is continuous with the inner surface of the cover portion on the opening side and the inner peripheral surface of the tubular portion and communicates with the recess. Is formed.

In the fourth aspect, in any one of the first to third aspects, one end of the cap body opens to the inner peripheral surface of the cover portion and the other end opens to the outer peripheral surface of the tubular portion. A passage is formed.

In a fifth aspect, in any one of the first to fourth aspects, a flange portion is formed on the outer peripheral portion of the tubular portion on the side where the cover portion is arranged.

1 Cylinder device 3 Cap 15 Cylinder 19 Opening 23 Seal member 31 Rod 81 Cap body 82 O-ring (ring-shaped member)
85 Cylindrical part 86 Cover part 91 Inner peripheral surface 98 Recessed 114 Inner surface 121 Communication groove 141 Outer peripheral surface 126 Passage

Claims (5)

A cylinder filled with working fluid and
A rod extending from the opening of the cylinder and
A seal member that closes between the cylinder and the rod at the position of the opening and slides the rod into contact with the rod.
A cap covering the opening of the cylinder and
It is a cylinder device equipped with
The cap
A tubular portion fitted to the outer peripheral portion of the cylinder and
A perforated disk-shaped cover portion that extends inward from the tubular portion and covers the opening, and
With the cap body,
A ring-shaped member interposed in the gap between the tubular portion and the cylinder,
A cylinder device comprising. The cylinder according to claim 1, wherein the cylindrical portion is provided with a recess recessed radially outward from the inner peripheral surface on the cover portion side of the position where the ring-shaped member is provided. Device. 2. The cap body is characterized in that a communication groove communicating with the recess is formed continuously on the inner surface of the cover portion on the opening side and the inner peripheral surface of the tubular portion. The cylinder device described. Any one of claims 1 to 3, wherein the cap body is formed with a passage in which one end opens to the inner peripheral surface of the cover portion and the other end opens to the outer peripheral surface of the tubular portion. The cylinder device according to one item. The cylinder device according to any one of claims 1 to 4, wherein a flange portion is formed on the outer peripheral portion of the tubular portion on the side on which the cover portion is arranged.

Images