WO2017057132A1 - 流体圧シリンダ - Google Patents
流体圧シリンダ Download PDFInfo
- Publication number
- WO2017057132A1 WO2017057132A1 PCT/JP2016/077848 JP2016077848W WO2017057132A1 WO 2017057132 A1 WO2017057132 A1 WO 2017057132A1 JP 2016077848 W JP2016077848 W JP 2016077848W WO 2017057132 A1 WO2017057132 A1 WO 2017057132A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- collar
- rod
- cushion bearing
- piston
- spacer
- Prior art date
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/20—Other details, e.g. assembly with regulating devices
- F15B15/22—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke
- F15B15/222—Other details, e.g. assembly with regulating devices for accelerating or decelerating the stroke having a piston with a piston extension or piston recess which throttles the main fluid outlet as the piston approaches its end position
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
- F15B15/08—Characterised by the construction of the motor unit
- F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
- F15B15/1423—Component parts; Constructional details
- F15B15/1457—Piston rods
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02F—DREDGING; SOIL-SHIFTING
- E02F9/00—Component parts of dredgers or soil-shifting machines, not restricted to one of the kinds covered by groups E02F3/00 - E02F7/00
- E02F9/20—Drives; Control devices
- E02F9/22—Hydraulic or pneumatic drives
- E02F9/2264—Arrangements or adaptations of elements for hydraulic drives
- E02F9/2271—Actuators and supports therefor and protection therefor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
- F15B2211/7051—Linear output members
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
- F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
- F15B2211/00—Circuits for servomotor systems
- F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
- F15B2211/755—Control of acceleration or deceleration of the output member
Definitions
- the present invention relates to a fluid pressure cylinder.
- a fluid pressure cylinder is provided with a cushion mechanism that generates a cushion pressure near the stroke end of the piston rod to decelerate the piston rod (JP6-40326Y2).
- the piston rod has a normal diameter portion and a small diameter portion formed to have a smaller diameter than the normal diameter portion.
- the piston is connected to the piston rod so as to face the step portion between the normal diameter portion and the small diameter portion.
- a cylindrical cushion bearing is provided on the outer periphery of the small diameter portion of the piston rod so as to be movable between the stepped portion and the piston rod.
- the inner diameter of the cushion bearing is larger than the outer diameter of the small diameter portion, and a gap (inner peripheral gap) is formed between the cushion bearing and the small diameter portion.
- the cylinder head has a bore formed so that a cushion bearing can enter.
- the cushion bearing enters the bore of the cylinder head before the extended position.
- the cushion bearing is pressed against the step of the piston rod by the pressure in the rod side chamber, and the flow of the working fluid from the rod side chamber to the port is limited only to the gap (outer circumferential gap) between the cushion bearing and the bore. .
- Resistance is given to the flow of the working fluid that moves from the rod side chamber to the port through the outer circumferential clearance, and the piston decelerates.
- the cushion bearing disclosed in JP6-40326Y2 has a gap with the piston rod, so that it tilts with respect to the piston rod and moves in the radial direction with respect to the piston rod.
- the tilt or movement of the cushion bearing may occur even after the cushion bearing has entered the bore of the cylinder head, and an unintended gap (passage) may be formed between the stepped portion and the cushion bearing.
- the working fluid in the rod side chamber not only moves to the port through the outer circumferential clearance, but also moves to the port through the unintended passage, and the flow of the working fluid is desired.
- the resistance is not given. That is, the rod side chamber and the port communicate with each other through an unintended passage, and the cushion performance is reduced.
- An object of the present invention is to provide a fluid pressure cylinder that can prevent a decrease in cushion performance.
- a fluid pressure cylinder includes a cylinder tube, a piston slidably received in the cylinder tube and defining a rod side chamber in the cylinder tube, a piston rod connected to the piston, and a rod side chamber. And a port for supplying the working fluid from the outside to the rod side chamber and discharging the working fluid in the rod side chamber to the outside, and the piston rod reaching the stroke end.
- a cushion bearing that restricts the flow of the working fluid discharged from the rod side chamber through the port, and a restricting portion that is provided on the piston rod so as to face the piston across the cushion bearing and restricts the movement of the cushion bearing in the axial direction.
- the diameter on the outer periphery of the piston rod between the cushion bearing and the restriction And the end surfaces of the cushion bearing and the collar facing each other are inclined symmetrically with respect to the central axis of the piston rod, and the end surfaces of the restricting portion and the collar facing each other Is formed in a planar shape crossing the central axis.
- FIG. 1 is a partial cross-sectional view of a hydraulic cylinder according to an embodiment of the present invention.
- FIG. 2 is an enlarged cross-sectional view around the cushion bearing, showing a state where the piston rod is in a normal stroke region.
- FIG. 3 is an enlarged cross-sectional view of the periphery of the head side port, showing a state where the piston rod is in the normal stroke region.
- FIG. 4 is an enlarged cross-sectional view around the head-side port, showing a state where the piston rod is in the vicinity of the stroke end.
- FIG. 5 is a cross-sectional view of the cushion bearing, the collar, and the spacer, showing a state in which the central axes of the cushion bearing, the collar, and the spacer are coincident with each other.
- FIG. 5 is a cross-sectional view of the cushion bearing, the collar, and the spacer, showing a state in which the central axes of the cushion bearing, the collar, and the spacer are coincident with each other
- FIG. 6 is a cross-sectional view of the cushion bearing, the collar, and the spacer, showing a state in which the cushion bearing is inclined with respect to the spacer.
- FIG. 7 is a cross-sectional view of the cushion bearing, the collar, and the spacer, showing a state in which the cushion bearing is displaced in the radial direction with respect to the spacer.
- FIG. 8 is a sectional view of the cushion bearing, the collar, and the spacer, and shows another example of the cushion bearing and the collar.
- FIG. 9 is an enlarged cross-sectional view of the vicinity of the head-side port, showing a state immediately after the hydraulic cylinder starts to contract.
- FIG. 10 is a cross-sectional view of the cushion bearing, the collar, and the spacer, and shows the state where the cushion bearing is assembled to the spacer in the reverse direction.
- FIG. 11 is a cross-sectional view of the cushion bearing, the collar, and the spacer, showing a state where the collar is assembled to the spacer in the reverse direction.
- FIG. 12 is a cross-sectional view of the cushion bearing, the collar, and the spacer, and shows another example of the first and second spacer steps.
- the hydraulic cylinder 100 is used as an actuator mounted on a machine such as a construction machine or an industrial machine.
- the hydraulic cylinder 100 is used as an arm cylinder mounted on a hydraulic excavator.
- a hydraulic cylinder 100 includes a cylindrical cylinder tube 10, a piston 20 that is slidably accommodated in the cylinder tube 10, and a piston rod 30 that is slidably inserted into the cylinder tube 10. .
- One end of the piston rod 30 is connected to the piston 20, and the other end extends to the outside of the cylinder tube 10.
- the one open end 11 of the cylinder tube 10 is closed by the cylinder head 40.
- the cylinder head 40 is formed in an annular shape and slidably supports the piston rod 30.
- the other open end 12 of the cylinder tube 10 is closed by a cylinder bottom 50.
- the hydraulic cylinder 100 is mounted on a machine such as a construction machine or an industrial machine using a connecting portion 30a provided on the other end of the piston rod 30 and a connecting portion 50a provided on the cylinder bottom 50.
- the piston 20 partitions the inside of the cylinder tube 10 into a rod side chamber 13 and an anti-rod side chamber 14.
- the rod side chamber 13 is defined by the cylinder tube 10
- the anti-rod side chamber 14 is defined by the cylinder tube 10, the piston 20 and the cylinder bottom 50.
- the cylinder tube 10 is provided with a head side port 15 that communicates with the rod side chamber 13 and a bottom side port 16 that communicates with the non-rod side chamber 14.
- the head side port and the bottom side port may be simply referred to as “ports”.
- the ports 15 and 16 are selectively connected to a hydraulic pump (not shown) or a tank (not shown) through a switching valve (not shown). When one of the ports 15 and 16 communicates with the hydraulic pump by the switching valve, the other communicates with the tank.
- the hydraulic cylinder 100 further includes an annular cushion bearing 60 provided on the outer periphery of the piston rod 30 and a cylindrical portion 41 provided on the inner periphery of the cylinder tube 10.
- the cylindrical portion 41 is formed integrally with the cylinder head 40 so that the cushion bearing 60 can be received.
- the piston rod 30 includes a rod main body 31 extending from the piston 20 to the outside of the cylinder tube 10 and an annular spacer 36 through which the rod main body 31 is inserted.
- the rod main body 31 has a small diameter portion 32 having an outer diameter substantially equal to the inner diameter of the spacer 36 and a large diameter portion 33 having an outer diameter larger than the outer diameter of the small diameter portion 32.
- the large diameter portion 33 is provided continuously to the small diameter portion 32, and a rod step portion 34 is formed between the large diameter portion 33 and the small diameter portion 32.
- the small diameter portion 32 is inserted into the spacer 36 and attached to the piston 20 by screwing.
- the spacer 36 includes an annular spacer main body 37 extending in the axial direction, and a flange 38 that protrudes radially outward from the end of the spacer main body 37 on the rod step 34 side.
- the spacer body 37 is sandwiched between the piston 20 and the rod step portion 34 by screwing the piston 20 into the small diameter portion 32. That is, the space between the piston 20 and the rod step 34 is ensured by the spacer body 37.
- the cushion bearing 60 is provided on the outer periphery of the spacer body 37.
- the inner diameter of the cushion bearing 60 is larger than the outer diameter of the spacer body 37. Therefore, the cushion bearing 60 is movable in the radial direction with respect to the spacer body 37.
- the outer diameter of the cushion bearing 60 is larger than the outer diameter of the collar portion 38. That is, the flange 38 faces the piston 20 with the cushion bearing 60 interposed therebetween, and restricts the movement of the cushion bearing 60 in the axial direction.
- the collar part 38 may be called a "restriction part.”
- a groove (slit) 61 extending from the inner peripheral surface of the cushion bearing 60 to the outer peripheral surface is formed on the end surface 60 a of the cushion bearing 60 facing the piston 20.
- a groove (slit) 62 extending in the axial direction is formed on the outer peripheral surface of the cushion bearing 60.
- An annular collar 70 is provided between the cushion bearing 60 and the collar portion 38.
- the inner diameter of the collar 70 is larger than the outer diameter of the spacer body 37, and the collar 70 is movable in the radial direction.
- a groove (slit) 71 extending from the inner peripheral surface of the collar 70 to the outer peripheral surface is formed on the end surface 70 a of the collar 70 facing the collar portion 38.
- annular inner peripheral passage 81 is formed between the inner peripheral surface of the cushion bearing 60 and the collar 70 and the outer peripheral surface of the spacer main body 37. Is done.
- the dimension in the axial direction of the cushion bearing 60 and the collar 70 is smaller than the dimension between the piston 20 and the flange 38. Therefore, the cushion bearing 60 and the collar 70 are movable in the axial direction between the piston 20 and the flange portion 38.
- the piston rod 30 since the piston rod 30 has the spacer 36 and the spacer 36 has the flange portion 38, the spacer 36 pressed by the piston 20 and the flange portion 38 pressed by the collar 70 are formed of the same material as the rod body 31. There is no need to do. Therefore, the rod main body 31 can be formed of an inexpensive and low-strength material, and the spacer 36 including the flange portion 38 can be formed of an expensive and high-strength material, and the piston rod 30 can be prevented from increasing in cost. The strength of can be increased.
- FIG. 3 is an enlarged cross-sectional view of the periphery of the head-side port 15 and shows a state where the piston rod 30 is in a normal stroke region (a state where the cushion bearing 60 does not enter the cylindrical portion 41).
- FIG. 4 is an enlarged cross-sectional view of the periphery of the head-side port 15 and shows a state where the piston rod 30 has reached the vicinity of the stroke end (a state where the cushion bearing 60 has entered the cylindrical portion 41).
- the outer diameter of the cylindrical portion 41 is substantially equal to the inner diameter of the cylinder tube 10, and the cylindrical portion 41 is fitted to the cylinder tube 10.
- Seal members 42 and 43 are disposed between the cylindrical portion 41 and the cylinder tube 10. The sealing members 42 and 43 prevent hydraulic oil from leaking from the gap between the outer peripheral surface of the cylindrical portion 41 and the inner peripheral surface of the cylinder tube 10.
- the inner diameter of the cylindrical portion 41 is larger than the outer diameter of the large diameter portion 33 of the rod main body 31. Therefore, when the piston rod 30 is in the normal stroke region, an annular passage 82 is formed by the inner peripheral surface of the cylindrical portion 41 and the outer peripheral surface of the large diameter portion 33, and the rod side chamber 13 and the port 15 are connected through the annular passage 82. Communicate. That is, when the piston rod 30 is in the normal stroke region and the hydraulic cylinder 100 is extended, the hydraulic oil in the rod side chamber 13 is discharged from the port 15 through the annular passage 82.
- the outer diameter of the cushion bearing 60 is substantially equal to the inner diameter of the cylindrical portion 41. Therefore, in the state where the cushion bearing 60 has entered the cylindrical portion 41, the rod side chamber 13 and the port 15 include the outer peripheral passage 83 formed by the groove 62 of the cushion bearing 60 and the inner peripheral surface of the cylindrical portion 41, and the inner peripheral portion. It communicates only through the passage 81.
- the hydraulic oil in the rod side chamber 13 moves to the port 15 only through the inner peripheral passage 81 and the outer peripheral passage 83. Since the flow passage cross sections of the inner peripheral passage 81 and the outer peripheral passage 83 are smaller than those of the annular passage 82 (see FIG. 3), resistance is given to the flow of hydraulic oil discharged from the rod side chamber 13 through the port 15. As a result, the pressure in the rod side chamber 13 increases and the piston rod 30 decelerates.
- the piston 20 and the collar 70 can be moved according to the operation of the hydraulic cylinder 100, specifically according to the pressure in the rod side chamber 13. It moves to and from the heel part 38.
- the cushion bearing 60 and the collar 70 move in a direction approaching the collar portion 38 due to a pressure difference between the rod side chamber 13 and the port 15. As a result, the cushion bearing 60 contacts the collar 70, and the collar 70 contacts the collar portion 38.
- a communication passage 84 that communicates the inner peripheral passage 81 and the port 15 is formed by the groove 71 and the collar portion 38 of the collar 70.
- the cross section of the communication passage 84 is smaller than the cross section of the inner peripheral passage 81. Therefore, a resistance is mainly given to the flow of the hydraulic oil that moves from the rod side chamber 13 to the port 15 through the inner peripheral passage 81 and the communication passage 84 mainly in the communication passage 84.
- the rod side chamber 13 and the port 15 communicate with each other through the outer peripheral passage 83 and also through the inner peripheral passage 81 and the communication passage 84.
- the groove 62 is not provided on the outer peripheral surface of the cushion bearing 60, and the rod side chamber 13 and the port 15 may communicate with each other only through the inner peripheral passage 81 and the communication passage 84.
- the groove 70 is not provided in the collar 70, and the rod side chamber 13 and the port 15 may communicate with each other only through the outer peripheral passage 83.
- the groove 62 of the cushion bearing 60 may not extend between both ends of the cushion bearing 60, and the rod side chamber 13 and the port 15 communicate with each other when the cushion bearing 60 enters the cylindrical portion 41. It is only necessary to have a length of
- the outer peripheral passage 83 is not limited to the form formed by the groove 62 and the inner peripheral surface of the cylindrical portion 41.
- the outer peripheral surface of the cushion bearing 60 may be formed in a planar shape without the groove 62, and the outer peripheral passage 83 may be formed in an annular shape between the outer peripheral surface of the cushion bearing 60 and the inner peripheral surface of the cylindrical portion 41.
- FIG. 5 is a cross-sectional view of the cushion bearing 60, the collar 70, and the spacer 36, and shows a state in which the central axes of the cushion bearing 60, the collar 70, and the spacer 36 are coincident.
- FIG. 5 shows a part of the piston 20.
- the end surfaces 60 b and 70 b of the cushion bearing 60 and the collar 70 facing each other are inclined symmetrically with respect to the central axis of the spacer 36.
- the end surface 60b of the cushion bearing 60 is inclined such that the radially inner edge 60c is positioned on the flange 38 side with respect to the radially outer edge 60d.
- the end surface 70b of the collar 70 is inclined such that the radially inner edge 70c is positioned on the flange 38 side with respect to the radially outer edge 70d.
- “Inclined symmetrically with respect to the central axis of the spacer 36” is not limited to the form in which the portions of the end faces 60b and 70b at the opposite positions with respect to the central axis of the spacer 36 are inclined at the same angle. Includes forms that are inclined at different angles.
- end surfaces 70a and 38a of the collar 70 and the collar portion 38 facing each other are formed in a planar shape that crosses the central axis of the collar 70 and the collar portion 38, respectively.
- the end faces 70b and 38a are formed substantially perpendicular to the central axis.
- FIG. 6 is a cross-sectional view of the cushion bearing 60, the collar 70, and the spacer 36, and shows a state in which the cushion bearing 60 is inclined with respect to the spacer 36.
- Such an inclination of the cushion bearing 60 is generated, for example, when the cylindrical portion 41 is inclined with respect to the piston rod 30.
- the inclination of the cylindrical portion 41 depends on the processing accuracy and mounting accuracy of the piston 20, the piston rod 30, the cylinder head 40, and the like.
- end surfaces 60b and 70b are formed substantially perpendicular to the central axis of the spacer 36, when the cushion bearing 60 is inclined with respect to the spacer 36, a partial gap is formed between the end surface 60b and the end surface 70b. The There is a possibility that hydraulic oil in the rod side chamber 13 (see FIG. 4 etc.) leaks from this gap and the cushion performance is lowered.
- the end surfaces 60 b and 70 b are inclined symmetrically with respect to the central axis of the spacer 36. Therefore, as shown in FIG. 6, even if the cushion bearing 60 is inclined with respect to the spacer 36, the end surface 60b is in sliding contact with the end surface 70b, so that a gap is not easily formed between the end surface 60b and the end surface 70b. Therefore, an unintended passage is unlikely to be formed between the end surface 60b and the end surface 70b, and a decrease in cushion performance can be prevented.
- FIG. 7 is a cross-sectional view of the cushion bearing 60, the collar 70, and the spacer 36, and shows a state where the cushion bearing 60 is displaced in the radial direction with respect to the spacer 36.
- Such a displacement of the cushion bearing 60 is caused by the displacement of the cylindrical portion 41 in the radial direction with respect to the piston rod 30, for example, similarly to the inclination of the cushion bearing 60.
- the collar 70 Since the collar 70 is provided so as to be movable in the radial direction, the collar 70 also moves in accordance with the displacement of the cushion bearing 60 as shown in FIG. Therefore, even if the end surfaces 60b and 70b are symmetrically inclined with respect to the central axis of the spacer 36, it is difficult to form a gap between the end surface 60b and the end surface 70b.
- end surfaces 70a, 38a of the collar 70 and the collar portion 38 facing each other are formed substantially perpendicular to the central axis of the spacer 36, even if the collar 70 moves in the radial direction with respect to the collar portion 38, the end surface 70a. It is difficult to form a gap between the end face 38a and the end face 38a. Therefore, it is difficult to form an unintended passage between the end surface 60b and the end surface 70b and between the end surface 70a and the end surface 38a, and it is possible to prevent a decrease in cushion performance.
- the end surfaces 60b and 70b may be flat.
- the end surfaces 60b and 70b are preferably curved surfaces, and more preferably part of a virtual spherical surface.
- the end faces 70 a and 38 a are formed substantially perpendicular to the central axis of the spacer 36, but the end faces 70 a and 38 a only need to cross the central axis of the spacer 36, and are relative to the central axis of the spacer 36. It may be inclined.
- FIG. 9 is an enlarged cross-sectional view of the periphery of the port 15 and shows a state immediately after the hydraulic cylinder 100 starts the contraction operation. Note that immediately before the hydraulic cylinder 100 starts the contraction operation, as shown in FIG. 4, the cushion bearing 60 contacts the collar 70 and the collar 70 contacts the collar portion 38.
- the hydraulic oil flows into the groove 71 of the collar 70.
- the pressure of the hydraulic oil in the groove 71 acts on the bottom surface (pressure receiving surface) 71 a of the groove 71 to press the collar 70 and the cushion bearing 60. That is, the bottom surface 71 a of the groove 71 receives the pressure of the hydraulic oil supplied from the port 15 in a direction away from the flange portion 38 in a state where the collar 70 is in contact with the flange portion 38.
- the collar 70 and the cushion bearing 60 move when the bottom surface 71a of the groove 71 receives the pressure of the hydraulic oil, the collar 70 can be prevented from sticking to the collar portion 38. Due to the movement of the collar 70 and the cushion bearing 60, a gap is formed between the collar 70 and the collar portion 38 as shown in FIG. The hydraulic oil from the port 15 flows into the inner peripheral passage 81 through this gap.
- the inner peripheral passage 81 and the rod side chamber 13 communicate with each other through the groove 61 of the cushion bearing 60. Therefore, the hydraulic oil in the inner peripheral passage 81 can be supplied to the rod side chamber 13.
- the rod side chamber 13 and the port 15 communicate with each other through the inner peripheral passage 81 immediately after the hydraulic cylinder 100 starts the contraction operation. Therefore, even when the cushion bearing 60 is not removed from the cylindrical portion 41, the hydraulic oil is easily supplied to the rod side chamber 13. Therefore, the responsiveness of the hydraulic cylinder 100 can be improved.
- a first spacer step (first rod step) 37 a that faces the piston 20 with a part of the cushion bearing 60 interposed therebetween is formed on the outer peripheral surface of the spacer body 37.
- the first spacer step 37a is formed by making the outer diameter of the spacer body 37 different from the first spacer step 37a.
- a bearing step portion 60e facing the first spacer step portion 37a is formed on the inner peripheral surface of the cushion bearing 60.
- the bearing step portion 60e is formed by making the inner diameter of the cushion bearing 60 different from the bearing step portion 60e.
- a second spacer step (second rod step) 37b facing the piston 20 with the cushion bearing 60 and a part of the collar 70 interposed therebetween is formed on the outer peripheral surface of the spacer body 37.
- the second spacer step portion 37b is formed by making the outer diameter of the spacer body 37 different from the second spacer step portion 37b.
- a collar step portion 70e facing the second spacer step portion 37b is formed on the inner peripheral surface of the collar 70.
- the color step portion 70e is formed by making the inner diameter of the collar 70 different from the color step portion 70e.
- the dimension L1 from the first spacer step 37a to the piston 20 is larger than the dimension L2 from the bearing step 60e to the end surface 60a. Therefore, the cushion bearing 60 does not protrude from the spacer 36 when the cushion bearing 60 is assembled to the spacer 36 in the correct orientation.
- the dimension L1 is smaller than the dimension L3 of the cushion bearing 60 in the axial direction. Therefore, as shown in FIG. 10, when the cushion bearing 60 is assembled to the spacer 36 in the reverse direction, the cushion bearing 60 protrudes from the spacer 36. Therefore, it can be easily determined whether or not the cushion bearing 60 is assembled to the spacer 36 in an appropriate direction.
- the dimension L4 from the second spacer step 37b to the piston 20 is larger than the dimension L5 from the collar step 70e to the end surface 60a when the cushion bearing 60 and the collar 70 are combined. Therefore, when the cushion bearing 60 and the collar 70 are assembled to the spacer 36 in the correct orientation, the cushion bearing 60 does not protrude from the spacer 36.
- the dimension L4 is smaller than the dimension L6 obtained by combining the cushion bearing 60 and the collar 70 in the axial direction. Therefore, as shown in FIG. 11, when the collar 70 is assembled to the spacer 36 in the reverse direction, the cushion bearing 60 protrudes from the spacer 36. Therefore, it can be easily determined whether or not the cushion bearing 60 is assembled to the spacer 36 in an appropriate direction.
- the first spacer step portion 37a is formed by making the outer diameter of the spacer body 37 different from the first spacer step portion 37a as a boundary, but is not limited to this form.
- FIG. 12 is a cross-sectional view showing another example of the first and second spacer steps 37a and 37b.
- the first spacer step 37 a may be formed by providing the spacer 36 with a rib 37 c that protrudes radially outward from the spacer body 37.
- the second spacer step 37b may be formed by a rib 37d that protrudes radially inward from the spacer body 37.
- the bearing step portion 60e is formed by changing the inner diameter of the cushion bearing 60 with the bearing step portion 60e as a boundary, but is not limited to this form.
- the bearing step portion 60 e may be formed by providing the cushion bearing 60 with a rib that protrudes radially inward from the cushion bearing 60.
- the collar step portion 70e may be formed by a rib that protrudes radially inward from the collar 70.
- the end surface 60b of the cushion bearing 60 and the end surface 70b of the collar 70 are formed to be symmetrically inclined with respect to the central axis of the spacer 36, even if the cushion bearing 60 is inclined, the end surface 60b and the end surface 70b are not intended. It is difficult to form a gap.
- the collar 70 is movable in the radial direction, even if the cushion bearing 60 is displaced, it is difficult to form an unintended gap between the end surface 60b of the cushion bearing 60 and the end surface 70b of the collar 70.
- the collar 70 and the end faces 70a, 38a of the collar portion 38 are formed in a plane shape that crosses the center of the spacer 36, even if the collar 70 moves in the radial direction, the collar 70 has an end face 70a and an end face of the collar portion 38. It is difficult to form an unintended gap between 38a.
- the cylinder tube 10 the piston 20 that is slidably accommodated in the cylinder tube 10, defines the rod side chamber 13 in the cylinder tube 10, the piston rod 30 that is connected to the piston 20, and the rod side chamber 13.
- a port 15 for supplying hydraulic oil from the outside to the rod side chamber 13 and discharging the hydraulic oil in the rod side chamber 13 to the outside, and a piston rod 30 movably provided on the outer periphery of the piston rod 30. Is provided on the piston rod 30 so as to face the piston 20 with the cushion bearing 60 sandwiched between the cushion bearing 60 and the cushion bearing 60 for restricting the flow of the hydraulic oil discharged from the rod side chamber 13 through the port 15 when reaching the stroke end.
- the flange 38 for restricting the movement of the cushion bearing 60 of the cushion, and the cushion A collar 70 provided on the outer periphery of the piston rod 30 between the ring 60 and the collar portion 38 so as to be movable in the radial direction.
- End surfaces 60b, 70b of the cushion bearing 60 and the collar 70 facing each other are The end faces 38a and 70a of the collar portion 38 and the collar 70 facing each other are formed in a plane that crosses the central axis.
- the end surfaces 60b and 70b of the cushion bearing 60 and the collar 70 facing each other are inclined symmetrically with respect to the central axis of the piston rod 30, so that even if the cushion bearing 60 is inclined with respect to the piston rod 30, the end surface 60b. It is difficult to form a gap between the end face 70b and the end face 70b. Further, since the collar 70 is movable in the radial direction, the collar 70 also moves with the displacement of the cushion bearing 60, and it is difficult to form a gap between the end faces 60b and 70b.
- the cushion bearing 60 and the spacer 36 each have a bearing step portion 60e and a first spacer step portion 37a facing each other, and a dimension L1 from the first spacer step portion 37a to the piston 20 is It is smaller than the dimension L3 of the cushion bearing 60 in the axial direction.
- the cushion bearing 60 is assembled to the spacer 36 in the opposite direction.
- the cushion bearing 60 protrudes from the spacer 36. Therefore, it can be easily determined whether or not the cushion bearing 60 is assembled to the spacer 36 in an appropriate direction.
- the collar 70 and the spacer 36 have a collar step portion 70e and a second spacer step portion 37b that face each other, and the dimension L4 from the second spacer step portion 37b to the piston 20 is an axis. This is smaller than the dimension L6 of the cushion bearing 60 and the collar 70 in the direction.
- the dimension L4 from the second spacer step 37b to the piston 20 is smaller than the dimension L6 of the cushion bearing 60 and the collar 70 in the axial direction.
- the cushion bearing 60 protrudes from the spacer 36. Therefore, it can be easily determined whether the collar 70 is assembled to the spacer 36 in an appropriate direction.
- an inner peripheral passage 81 is formed between the cushion bearing 60 and the piston rod 30, and between the collar 70 and the piston rod 30, and the rod side chamber 13 and the port 15 are connected to the inner periphery. It communicates through the passage 81.
- the rod side chamber 13 and the port 15 communicate with each other through the inner peripheral passage 81, so that the hydraulic oil in the rod side chamber 13 moves toward the port 15 through the inner peripheral passage 81 when the cushion bearing 60 restricts the flow of the hydraulic oil. Move. Therefore, an increase in pressure in the inner peripheral passage 81 can be prevented, and the inner peripheral passage 81 can have a resistance imparting function.
- a communication path 84 that connects the inner peripheral path 81 and the port 15 is formed between the collar 70 and the collar portion 38.
- the inner peripheral passage 81 and the port 15 communicate with each other by the communication passage 84, so that the hydraulic oil in the rod side chamber 13 passes through the inner peripheral passage 81 and the communication passage 84 when the cushion bearing 60 restricts the flow of the hydraulic oil. Move towards port 15. Therefore, the communication path 84 can have a resistance imparting function.
- the collar 70 is relatively movable in the axial direction with respect to the piston rod 30, and the pressure of the hydraulic oil supplied from the port 15 is applied from the flange portion 38 while being in contact with the flange portion 38. It has a pressure receiving surface that is received in the direction of separation.
- the collar 70 since the collar 70 has a pressure receiving surface that receives the pressure of the hydraulic oil in a direction away from the flange portion 38, the collar 70 has a flange portion due to the hydraulic oil pressure from the port 15 when the hydraulic cylinder 100 is contracted. A gap is formed between the flange 38 and the flange 38. Therefore, the hydraulic oil from the port 15 can be supplied to the rod side chamber 13 through the gap between the cushion bearing 60 and the piston rod 30, and the responsiveness of the hydraulic cylinder 100 can be improved.
- the cylinder tube 10 further includes a cylindrical portion 41 that is formed so as to be able to receive the cushion bearing 60.
- the outer periphery of the cushion bearing 60 is provided.
- An outer peripheral passage 83 that connects the rod side chamber 13 and the port 15 is formed between the surface and the inner peripheral surface of the cylindrical portion 41.
- the outer peripheral passage 83 can have a resistance imparting function.
- the piston rod 30 includes a rod main body 31 having a rod step portion 34 facing the piston 20, and a spacer that is provided on the outer periphery of the rod main body 31 and secures an interval between the piston 20 and the rod step portion 34.
- the cushion bearing 60 and the collar 70 are provided on the outer periphery of the spacer 36, and the spacer 36 has a flange 38.
- the piston rod 30 has the spacer 36 that secures the distance between the piston 20 and the rod step portion 34, and the spacer 36 has the flange portion 38, so that it is pressed by the spacer 36 pressed by the piston 20 and the collar 70. It is not necessary to form the flange portion 38 with the same material as the rod body 31. Therefore, the rod main body 31 can be formed of an inexpensive and low-strength material, and the spacer 36 including the flange portion 38 can be formed of an expensive and high-strength material, and the piston rod 30 can be prevented from increasing in cost. The strength of can be increased.
- the spacer 36 may not have the flange portion 38 as the restricting portion, and the restricting portion may be provided in the rod main body 31.
- the piston rod 30 may not have the spacer 36.
- the spacer 36 of the piston rod 30 and the rod body 31 may be integrally formed. By integrally molding the spacer 36 and the rod main body 31, the number of parts of the hydraulic cylinder 100 can be reduced.
- the first and second spacer step portions 37a and 37b of the spacer 36 are connected to the piston rod 30 by the first and second rods. It is formed as a step.
- the outer peripheral passage 83 may not be formed between the cushion bearing 60 and the cylindrical portion 41.
- the rod side chamber 13 and the port 15 may communicate with each other through a through hole formed in the spacer 36 or a through hole formed in the cushion bearing 60.
- the pressure receiving surface is not limited to the bottom surface 71 a of the groove 71.
- a gap is formed between the end face 70a of the collar 70 and the end face 38a of the collar portion 38, and flows into this gap.
- the pressure of the hydraulic oil may be applied to the end surface 70a. That is, the end surface 70a formed in a rough surface shape may be used as the pressure receiving surface. Also by making the end face 70a rough, sticking between the collar 70 and the collar portion 38 can be prevented.
- the communication path 84 is not limited to the form formed by the groove 71 and the collar portion 38 of the collar 70. Instead of the groove 71 formed in the collar 70, a groove may be formed in the collar portion 38, and the communication path 84 may be formed by the groove and the end surface 70 a of the collar 70. That is, the communication path 84 only needs to be formed between the collar 70 and the collar part (restriction part) 38.
- the inner peripheral passage 81 and the port 15 communicate with each other through a through hole formed in the collar 70 or a through hole formed in the collar portion 38 instead of the communication passage 84 between the collar 70 and the collar portion 38. Also good.
- the inner peripheral passage 81 and the port 15 may communicate with each other through a groove formed in the end surface 60 b of the cushion bearing 60. That is, the inner peripheral passage 81 and the port 15 may communicate with each other through another passage without providing the communication passage 84 between the collar 70 and the collar portion 38.
- the collar end surface 70a may be formed in a flat shape.
- the inner peripheral passage 81 is not limited to an annular shape.
- a groove formed in the spacer 36, a groove formed in the cushion bearing 60, or a groove formed in the collar 70 may be used as the inner peripheral passage 81.
- the rod side chamber 13 and the port 15 communicate with each other through a through hole formed in the spacer 36, a through hole formed in the cushion bearing 60, or a through hole formed in the collar 70 instead of the inner peripheral passage 81. Also good.
- the cushion The bearing 60 may be tilted or displaced. In the hydraulic cylinder 100, it is difficult to form an unintended passage even when the cushion bearing 60 is inclined or displaced. Therefore, it is possible to prevent the rod side chamber 13 and the port 15 from communicating with each other through an unintended passage, and it is possible to prevent a decrease in cushion performance.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Fluid Mechanics (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Actuator (AREA)
Abstract
Description
Claims (8)
- 流体圧シリンダであって、
シリンダチューブと、
前記シリンダチューブに摺動自在に収容され、前記シリンダチューブ内にロッド側室を画定するピストンと、
前記ピストンに連結されたピストンロッドと、
前記ロッド側室に連通し、外部からの作動流体を前記ロッド側室に供給するとともに前記ロッド側室内の作動流体を外部に排出するためのポートと、
前記ピストンロッドの外周に移動自在に設けられ、前記ピストンロッドがストローク端に達する際に前記ロッド側室から前記ポートを通じて排出される作動流体の流れを絞るクッションベアリングと、
前記クッションベアリングを挟んで前記ピストンと対向して前記ピストンロッドに設けられ、軸方向への前記クッションベアリングの移動を制限する制限部と、
前記クッションベアリングと前記制限部との間で前記ピストンロッドの外周に径方向に移動自在に設けられたカラーと、を備え、
前記クッションベアリングと前記カラーの互いに対向する端面は、前記ピストンロッドの中心軸に対して対称的に傾斜しており、
前記制限部と前記カラーの互いに対向する端面は、前記中心軸を横切る平面状に形成されている、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記クッションベアリング及び前記ピストンロッドは、それぞれ、互いに対向するベアリング段部及び第1ロッド段部を有し、
前記第1ロッド段部から前記ピストンまでの寸法は、軸方向における前記クッションベアリングの寸法と比較して小さい、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記カラー及び前記ピストンロッドは、それぞれ、互いに対向するカラー段部及び第2ロッド段部を有し、
前記第2ロッド段部から前記ピストンまでの寸法は、軸方向における前記クッションベアリングと前記カラーとを合わせた寸法と比較して小さい、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記クッションベアリングと前記ピストンロッドとの間、及び前記カラーと前記ピストンロッドとの間には内周通路が形成されており、前記ロッド側室と前記ポートとが前記内周通路を通じて連通する、
流体圧シリンダ。 - 請求項4に記載の流体圧シリンダであって、
前記カラーと前記制限部との間には、前記内周通路と前記ポートとを連通する連通路が形成されている、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記カラーは、前記ピストンロッドに対して軸方向に相対移動自在であり、前記制限部に接した状態で、前記ポートから供給される作動流体の圧力を前記制限部から離間する方向に受ける受圧面を有する、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記シリンダチューブに設けられ、前記クッションベアリングを受け入れ可能に形成された円筒部を更に有し、
前記クッションベアリングが前記円筒部に進入した状態において、前記クッションベアリングの外周面と前記円筒部の内周面との間に前記ロッド側室と前記ポートとを連通する外周通路が形成される、
流体圧シリンダ。 - 請求項1に記載の流体圧シリンダであって、
前記ピストンロッドは、
前記ピストンと対向するロッド段部を有するロッド本体と、
前記ロッド本体の外周に設けられ前記ピストンと前記ロッド段部との間隔を確保するスペーサと、を有し、
前記クッションベアリング及び前記カラーは、前記スペーサの外周に設けられており、
前記スペーサは、前記制限部を有する、流体圧シリンダ。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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CN201680056350.7A CN108026947B (zh) | 2015-10-01 | 2016-09-21 | 流体压缸 |
US15/765,075 US10451093B2 (en) | 2015-10-01 | 2016-09-21 | Fluid pressure cylinder |
EP16851306.7A EP3358199B1 (en) | 2015-10-01 | 2016-09-21 | Fluid pressure cylinder |
KR1020187010335A KR102089193B1 (ko) | 2015-10-01 | 2016-09-21 | 유체압 실린더 |
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JP2015195786A JP6581457B2 (ja) | 2015-10-01 | 2015-10-01 | 流体圧シリンダ |
JP2015-195786 | 2015-10-01 |
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US (1) | US10451093B2 (ja) |
EP (1) | EP3358199B1 (ja) |
JP (1) | JP6581457B2 (ja) |
KR (1) | KR102089193B1 (ja) |
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DE202019005218U1 (de) * | 2019-12-23 | 2021-03-24 | Bümach Engineering International B.V. | Endlagengedämpfter Arbeitszylinder |
WO2024039956A1 (en) | 2022-08-18 | 2024-02-22 | Caterpillar Inc. | Hydraulic actuator for work machine |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
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JPH0640326Y2 (ja) * | 1988-06-28 | 1994-10-19 | カヤバ工業株式会社 | 油圧シリンダのクッション装置 |
JPH1182426A (ja) * | 1997-09-16 | 1999-03-26 | Hitachi Constr Mach Co Ltd | 油圧シリンダのクッション装置 |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
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US3067726A (en) * | 1961-02-27 | 1962-12-11 | Int Basic Economy Corp | Cushioning structure for fluid power cylinders |
JPS6040326Y2 (ja) * | 1982-06-22 | 1985-12-05 | 日本国有鉄道 | 事故復旧用仮可動ビ−ム |
JPH0744805Y2 (ja) | 1990-07-09 | 1995-10-11 | 株式会社ナブコ | 油圧シリンダのクッション装置 |
DE19836422C2 (de) * | 1998-08-12 | 2002-10-24 | Mannesmann Rexroth Ag | Druckmittelbetätigter Arbeitszylinder |
JP5091879B2 (ja) * | 2009-01-13 | 2012-12-05 | カヤバ工業株式会社 | 流体圧シリンダ |
CN201836139U (zh) * | 2010-07-23 | 2011-05-18 | 三一重工股份有限公司 | 一种液压油缸及液压缓冲系统、挖掘机和混凝土泵车 |
KR101536503B1 (ko) * | 2011-03-24 | 2015-07-13 | 카야바 고교 가부시기가이샤 | 유체압 실린더의 쿠션 기구 |
JP5789456B2 (ja) * | 2011-09-06 | 2015-10-07 | カヤバ工業株式会社 | 流体圧シリンダ |
JP6113996B2 (ja) * | 2012-10-11 | 2017-04-12 | Kyb株式会社 | 流体圧シリンダ |
JP6040326B2 (ja) * | 2014-08-15 | 2016-12-07 | H&Tテクノロジー株式会社 | 同相雑音除去回路及び差動伝送路 |
-
2015
- 2015-10-01 JP JP2015195786A patent/JP6581457B2/ja active Active
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2016
- 2016-09-21 WO PCT/JP2016/077848 patent/WO2017057132A1/ja active Application Filing
- 2016-09-21 KR KR1020187010335A patent/KR102089193B1/ko active IP Right Grant
- 2016-09-21 EP EP16851306.7A patent/EP3358199B1/en active Active
- 2016-09-21 CN CN201680056350.7A patent/CN108026947B/zh active Active
- 2016-09-21 US US15/765,075 patent/US10451093B2/en active Active
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH0640326Y2 (ja) * | 1988-06-28 | 1994-10-19 | カヤバ工業株式会社 | 油圧シリンダのクッション装置 |
JPH1182426A (ja) * | 1997-09-16 | 1999-03-26 | Hitachi Constr Mach Co Ltd | 油圧シリンダのクッション装置 |
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KR20180049088A (ko) | 2018-05-10 |
CN108026947B (zh) | 2020-03-10 |
EP3358199A1 (en) | 2018-08-08 |
EP3358199B1 (en) | 2020-08-26 |
US10451093B2 (en) | 2019-10-22 |
US20180274565A1 (en) | 2018-09-27 |
JP6581457B2 (ja) | 2019-09-25 |
KR102089193B1 (ko) | 2020-03-13 |
EP3358199A4 (en) | 2019-06-26 |
CN108026947A (zh) | 2018-05-11 |
JP2017067231A (ja) | 2017-04-06 |
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