WO2023007890A1 - 流体圧シリンダ - Google Patents
流体圧シリンダ Download PDFInfo
- Publication number
- WO2023007890A1 WO2023007890A1 PCT/JP2022/018718 JP2022018718W WO2023007890A1 WO 2023007890 A1 WO2023007890 A1 WO 2023007890A1 JP 2022018718 W JP2022018718 W JP 2022018718W WO 2023007890 A1 WO2023007890 A1 WO 2023007890A1
- Authority
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- WIPO (PCT)
- Prior art keywords
- piston
- rod
- piston rod
- fluid pressure
- stepped portion
- Prior art date
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- 239000012530 fluid Substances 0.000 title claims abstract description 49
- 230000002093 peripheral effect Effects 0.000 claims description 28
- 238000001514 detection method Methods 0.000 claims description 20
- 230000000903 blocking effect Effects 0.000 claims 1
- 230000006835 compression Effects 0.000 claims 1
- 238000007906 compression Methods 0.000 claims 1
- 239000010720 hydraulic oil Substances 0.000 description 19
- 230000007257 malfunction Effects 0.000 description 9
- 230000004048 modification Effects 0.000 description 7
- 238000012986 modification Methods 0.000 description 7
- 239000003921 oil Substances 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 238000007789 sealing Methods 0.000 description 3
- 238000007599 discharging Methods 0.000 description 2
- 238000002845 discoloration Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000005192 partition Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
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
- F15B15/08—Characterised by the construction of the motor unit
- F15B15/14—Characterised by the construction of the motor unit of the straight-cylinder type
- F15B15/149—Fluid interconnections, e.g. fluid connectors, passages
-
- 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
- F15B15/1447—Pistons; Piston to piston rod assemblies
- F15B15/1452—Piston sealings
-
- 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
-
- 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
- F15B15/1461—Piston rod sealings
-
- 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
- F15B20/00—Safety arrangements for fluid actuator systems; Applications of safety devices in fluid actuator systems; Emergency measures for fluid actuator systems
-
- 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
- F15B2211/60—Circuit components or control therefor
- F15B2211/63—Electronic controllers
- F15B2211/6303—Electronic controllers using input signals
- F15B2211/6306—Electronic controllers using input signals representing a pressure
-
- 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
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/857—Monitoring of fluid pressure systems
-
- 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
- F15B2211/80—Other types of control related to particular problems or conditions
- F15B2211/86—Control during or prevention of abnormal conditions
- F15B2211/863—Control during or prevention of abnormal conditions the abnormal condition being a hydraulic or pneumatic failure
- F15B2211/864—Failure of an output member, e.g. actuator or motor failure
Definitions
- the present invention relates to fluid pressure cylinders.
- JP2004-263713A discloses a fluid pressure cylinder having a cylinder body in which a piston is reciprocally mounted, and a piston rod attached to the piston and protruding outside from an end of the cylinder body.
- a piston is attached to the piston rod by being threadedly coupled to the end of the piston rod.
- An object of the present invention is to prevent malfunction of a fluid pressure cylinder caused by loosening of a piston member.
- a fluid pressure cylinder comprising a cylinder tube, a piston rod reciprocally inserted into the cylinder tube, and a fluid flowing in the cylinder tube connected to the tip of the piston rod.
- a piston member that defines a pressure chamber; and a rod that is provided inside the piston rod and has one opening that opens to the outer peripheral surface of the piston rod inside the cylinder tube and the other opening that opens outside the cylinder tube.
- an inner passage and a detecting portion provided outside the cylinder tube for detecting that the working fluid is led to the rod inner passage.
- the detection portion is connected to the fluid pressure through between the stepped portion and the piston member. It is detected that the working fluid is led from the chamber to the intra-rod passage.
- FIG. 1 is a partial cross-sectional view of a fluid pressure cylinder according to an embodiment of the invention.
- FIG. 2 is a partial cross-sectional view of a fluid pressure cylinder according to an embodiment of the present invention, showing a state in which the piston member is loosened with respect to the piston rod.
- FIG. 3 is a partial cross-sectional view of a fluid pressure cylinder according to Modification 2 of the embodiment of the present invention.
- a fluid pressure cylinder according to an embodiment of the present invention will be described with reference to FIG. Below, the case where the fluid pressure cylinder is the hydraulic cylinder 100 that uses hydraulic oil as the hydraulic fluid will be described.
- the hydraulic cylinder 100 is used as an actuator mounted on construction machinery and industrial machinery.
- the hydraulic cylinder 100 is used as an actuator that drives a boom, an arm, a bucket, etc. mounted on a hydraulic excavator.
- the hydraulic cylinder 100 includes a cylindrical cylinder tube 10, a piston rod 20 inserted into the cylinder tube 10 so as to be reciprocating, and a piston rod 20 connected to the tip of the piston rod 20 and inserted into the cylinder tube 10. It includes a piston member 30 that partitions a rod-side chamber 11 and an anti-rod-side chamber 12 as fluid pressure chambers, and a cylinder head 40 that closes the open end of the cylinder tube 10 .
- the hydraulic cylinder 100 expands and contracts in the axial direction by supplying working oil from a hydraulic source to one of the rod-side chamber 11 and the anti-rod-side chamber 12 and discharging the working oil from the other to the tank.
- a working fluid such as a water-soluble substitute fluid may be used instead of oil as the hydraulic fluid.
- the piston rod 20 has a small-diameter portion 21 formed on the distal end side and connected to the piston member 30, and a large-diameter portion 22 having an outer diameter larger than that of the small-diameter portion 21 and slidably supported by the cylinder head 40. . Between the small-diameter portion 21 and the large-diameter portion 22, a stepped portion 23, which is an annular surface perpendicular to the axial direction of the piston rod 20, is provided. Further, the piston rod 20 has a curved surface portion 24 which is provided at a boundary portion between the small diameter portion 21 and the stepped portion 23 and which is recessed in an annular shape. The curved surface portion 24 is recessed radially inward of the small diameter portion 21 .
- Curved surface portion 24 alleviates stress concentration occurring at the boundary between small diameter portion 21 and stepped portion 23 .
- a part of the small-diameter portion 21 is provided with a male threaded portion 21 a that is screwed with the piston member 30 .
- the large-diameter portion 22 extends from the open end of the cylinder tube 10, and is provided with an attachment portion 22a for attachment to other equipment or the like.
- the attachment portion 22a is attached to the end portion of the large diameter portion 22 by welding, for example.
- the mounting portion 22a is also a part of the piston rod 20. As shown in FIG.
- An intra-rod passage 50 is provided in the piston rod 20 so as to extend in the axial direction.
- One opening 51 of the intra-rod passage 50 opens to the outer peripheral surface of the small diameter portion 21 inside the cylinder tube 10
- the other opening 52 opens outside the cylinder tube 10 .
- the opening 51 is provided in the vicinity of the stepped portion 23 and between the stepped portion 23 and the male screw portion 21a.
- the opening 52 is provided on the outer peripheral surface of the mounting portion 22a. Therefore, the opening 52 is positioned outside the cylinder tube 10 even when the hydraulic cylinder 100 is most contracted.
- the intra-rod passage 50 is machined before the attachment portion 22a is attached to the end of the piston rod 20. Specifically, it is formed by cutting from the end of the piston rod 20 in the axial direction of the piston rod 20 and cutting from the outer peripheral surface of the mounting portion 22a toward the center of the mounting surface to the piston rod 20. be.
- the hydraulic cylinder 100 is provided with a pressure sensor 60 as a detection unit that is provided outside the cylinder tube 10 and detects that hydraulic oil is led to the intra-rod passage 50 .
- the pressure sensor 60 is attached to the attachment portion 22a via a joint 80. As shown in FIG.
- the joint 80 is formed with a passage 81 that communicates with the intra-rod passage 50 and guides hydraulic oil from the intra-rod passage 50 to the pressure sensor 60 .
- the pressure sensor 60 detects that hydraulic fluid is introduced from the opening 51 to the intra-rod passage 50, and wirelessly transmits the detection information to an external device (not shown) as an electric signal.
- the piston member 30 has a piston body portion 31 that slides along the inner peripheral surface of the cylinder tube 10 and a ring member 32 provided between the piston body portion 31 and the step portion 23 of the piston rod 20 .
- the piston body 31 and the ring member 32 are made of the same material.
- the ring member 32 has a smaller outer diameter than the piston body portion 31 .
- the ring member 32 is in surface contact with the piston main body 31 , and hydraulic oil is not guided between the piston main body 31 and the ring member 32 .
- a part of the inner peripheral surface of the piston main body 31 is provided with a female threaded portion 31a that is screwed with the male threaded portion 21a of the piston rod 20 .
- the female threaded portion 31 a is screwed into the male threaded portion 21 a of the piston rod 20 until the ring member 32 contacts the stepped portion 23 .
- the piston member 30 is connected to the piston rod 20 with one end face 33 in contact with the stepped portion 23 of the piston rod 20 .
- the opening 51 of the intra-rod passage 50 is provided between the stepped portion 23 and the male threaded portion 21a. Therefore, when the piston member 30 is connected to the piston rod 20 , the ring member 32 of the piston member 30 is in contact with the stepped portion 23 and covers the opening 51 of the rod internal passage 50 . Shut off hydraulic fluid flow to 50 . Thus, ring member 32 blocks opening 51 .
- the ring member 32 has a tapered portion 32 a which is provided on the inner peripheral surface of the ring member 32 so as to face the curved surface portion 24 of the piston rod 20 and whose inner diameter increases toward the end surface 33 .
- the tapered portion 32 a is annularly provided on the inner peripheral surface of the ring member 32 over the end surface 33 . Contact between the ring member 32 and the curved surface portion 24 of the piston rod 20 is prevented by the tapered portion 32a. This ensures contact between the piston member 30 and the curved surface portion 24 of the piston rod 20 .
- the hydraulic cylinder 100 is provided with an annular O-ring 70 as a sealing member that is compressed between the piston member 30 and the piston rod 20 and seals between them.
- An annular groove 31 b in which an O-ring 70 is accommodated is formed in the inner peripheral surface of the piston body portion 31 .
- the annular groove 31 b is formed to open at the end surface of the piston body 31 facing the stepped portion 23 with the ring member 32 interposed therebetween. That is, the annular groove 31b is formed to open at the end surface of the piston main body portion 31 that contacts the ring member 32 . Therefore, it is easy to accommodate the O-ring 70 in the annular groove 31b during assembly.
- the cylinder head 40 is a substantially cylindrical member through which the piston rod 20 is inserted.
- the cylinder head 40 has a flange portion 41, and the flange portion 41 is screwed to the end portion of the cylinder tube 10 with a screw or the like (not shown). Note that the flange portion 41 may be fastened to the end portion of the cylinder tube 10 with a bolt or the like.
- the cylinder head 40 is provided with a supply/discharge port 42 for supplying/discharging hydraulic oil to/from the rod-side chamber 11 .
- One end of the supply/discharge port 42 faces the outer peripheral surface of the piston rod 20 and communicates with the rod-side chamber 11 through an annular gap between the outer peripheral surface of the piston rod 20 and the inner peripheral surface of the cylinder head 40 .
- the other end of the supply/discharge port 42 opens to the outer peripheral surface of the cylinder head 40 .
- a hydraulic pipe (not shown) is connected to the other end of the supply/discharge port 42, and the hydraulic pipe is connected to a hydraulic source or a tank through a switching valve.
- the piston member 30 may loosen with respect to the piston rod 20 (hereinafter also simply referred to as "loosening of the piston member 30"). As the loosening of the piston member 30 progresses, the hydraulic cylinder 100 malfunctions. Specifically, when a load exceeding the axial force in the connection between the piston member 30 and the piston rod 20 acts on the piston member 30, the threaded connection between the female threaded portion 31a of the piston member 30 and the male threaded portion 21a of the piston rod 20 is maintained. As it is, the piston rod 20 extends axially.
- the looseness of the piston member 30 can be detected early by the pressure sensor 60 before the hydraulic cylinder 100 malfunctions. Below, the detection of looseness of the piston member 30 by the pressure sensor 60 will be described in detail with reference to FIGS.
- the ring member 32 contacts the stepped portion 23 of the piston rod 20 as described above, and the movement from the rod-side chamber 11 to the intra-rod passage 50 through the both. Oil flow is blocked. Further, the inner peripheral surface of the piston member 30 and the outer peripheral surface of the small diameter portion 21 of the piston rod 20 are communicated by the screw connection between the female threaded portion 31a of the piston body portion 31 and the male threaded portion 21a of the piston rod 20 and the O-ring 70. Also, the flow of hydraulic oil from the anti-rod side chamber 12 to the intra-rod passage 50 is blocked.
- the O-ring 70 blocks the flow of hydraulic oil from the rod-side chamber 11 to the intra-rod passage 50 through the space between the piston body 31 and the ring member 32 . Therefore, hydraulic fluid is not led from the rod-side chamber 11 and the anti-rod-side chamber 12 to the intra-rod passage 50 .
- the O-ring 70 is provided on the side opposite to the stepped portion 23 of the piston rod 20 with the opening 51 of the intra-rod passage 50 as a boundary. Therefore, communication between the rod-side chamber 11 and the anti-rod-side chamber 12 through the inner peripheral surface of the piston member 30 and the outer peripheral surface of the small diameter portion 21 of the piston rod 20 is further blocked by the O-ring 70 . As a result, when a gap is created between the ring member 32 of the piston member 30 and the stepped portion 23 , the hydraulic oil that has flowed into the gap from the rod-side chamber 11 is not guided to the anti-rod-side chamber 12 and instead flows into the rod internal passage 50 . be guided.
- the annular groove 31b and the O-ring 70 do not necessarily need to be provided, and are not essential components of the present invention, although the looseness detection accuracy of the piston member 30 is lowered.
- the annular groove 31b of the piston main body portion 31 of the piston member 30 is formed so as to open at the end surface of the piston rod 20 facing the step portion 23. Therefore, if the end surface of the piston main body 31 is configured to contact the stepped portion 23 of the piston rod 20, the contact area between the piston member 30 and the stepped portion 23 becomes small, so the sealing performance between the two is reduced. becomes lower.
- the ring member 32 is provided between the piston body portion 31 and the stepped portion 23 of the piston rod 20 , and the ring member 32 contacts the stepped portion 23 . Therefore, the contact area between the piston member 30 and the stepped portion 23 is ensured, and the flow of hydraulic oil to the in-rod passage 50 passing between them can be further blocked. Therefore, the looseness detection accuracy of the piston member 30 by the pressure sensor 60 is improved.
- the contact surface between the piston member 30 and the stepped portion 23 of the piston rod 20 is a surface that receives an axial force due to screw fastening when the piston member 30 is connected to the piston rod 20 .
- the contact area between the piston member 30 and the step portion 23 is secured by the ring member 32 , so the fastening force of the piston member 30 to the piston rod 20 can be secured.
- the pressure sensor 60 detects that hydraulic fluid is led from the rod-side chamber 11 to the intra-rod passage 50, and the detection information is wirelessly transmitted to an external device (not shown) as an electric signal. be sent. Therefore, even when construction machinery or industrial machinery equipped with the hydraulic cylinder 100 is remotely controlled by an operator using a terminal or the like, the looseness detection information of the piston member 30 by the pressure sensor 60, for example, is transmitted to the terminal or the like. By doing so, the operator can recognize the looseness of the piston member 30 .
- the detection information may be transmitted to the external device by wire.
- the communication between the rod-side chamber 11 and the anti-rod-side chamber 12 through the inner peripheral surface of the piston member 30 and the outer peripheral surface of the small diameter portion 21 of the piston rod 20 is blocked by the O-ring 70. be.
- the piston member 30 is loosened and a gap is created between the ring member 32 of the piston member 30 and the stepped portion 23 , the hydraulic oil that has flowed into the gap is guided to the intra-rod passage 50 . Therefore, the looseness detection accuracy of the piston member 30 by the pressure sensor 60 is improved.
- the looseness detection information of the piston member 30 by the pressure sensor 60 for example, The operator can perceive the looseness of the piston member 30 by transmitting to the terminal or the like.
- the pressure sensor 60 is used as the detection unit that detects that the hydraulic oil is led to the intra-rod passage 50 .
- the detection unit is not limited to this, and may be a sensor 160 such as an image sensor or a liquid level sensor.
- a sensor 160 facing the opening 52 of the intra-rod passage 50, there are a member that reacts with hydraulic fluid and changes color, a member that changes shape due to reaction with hydraulic fluid, hydraulic pressure, etc., and a container that stores hydraulic fluid.
- a sensor 160 detects discoloration and shape change of the member and the amount of hydraulic oil in the container, thereby detecting that the hydraulic oil is led to the intra-rod passage 50 .
- a sensor 160 other than the pressure sensor such as an image sensor or a liquid level sensor, can detect that hydraulic oil is led to the intra-rod passage 50 .
- the operator may visually observe the discoloration or shape change of the member, or the amount of hydraulic oil in the container to recognize the looseness of the piston member 30.
- FIG. the member provided facing the opening 52 of the intra-rod passage 50 and the container itself serve as the detection section.
- the ring member 32 is provided between the piston main body 31 and the stepped portion 23 of the piston rod 20, and the ring member 32 comes into contact with the stepped portion 23 to allow the rod-side chamber 11 to pass therebetween.
- the flow of hydraulic oil to the inner passage 50 is blocked.
- the piston member 30 may be composed only of the piston main body portion 31 without the ring member 32 . Even with this configuration, malfunction of the hydraulic cylinder 100 due to the loosening of the piston member 30 can be prevented, as in the above-described embodiment.
- the O-ring 70 is provided on the side opposite to the stepped portion 23 of the piston rod 20 across the opening 51 of the intra-rod passage 50 as in the above-described embodiment.
- the annular groove 31 b for accommodating the O-ring 70 is not formed open in the end surface of the piston body portion 31 . Therefore, it is difficult to accommodate the O-ring 70 in the annular groove 31b.
- the ring member 32 is provided and the annular groove 31b opens to the end surface of the piston body 31, so that the O-ring 70 can be easily accommodated in the annular groove 31b.
- a hydraulic cylinder 100 as a fluid pressure cylinder comprises a cylinder tube 10, a piston rod 20 reciprocally inserted into the cylinder tube 10, and a tip end of the piston rod 20 connected to the cylinder tube 10 as a fluid pressure chamber.
- a piston member 30 that partitions the rod-side chamber 11 and the anti-rod-side chamber 12, and a piston member 30 provided in the piston rod 20, one opening 51 opening to the outer peripheral surface of the piston rod 20 in the cylinder tube 10, and the other opening 52 is provided outside the cylinder tube 10 and detecting portions 60 and 160 provided outside the cylinder tube 10 for detecting that the working fluid is led to the rod internal passage 50, and the piston member 30 is One end surface 33 contacts an annular stepped portion 23 provided on the outer peripheral surface of the piston rod 20, and is connected to the piston rod 20 in a state in which one opening portion 51 of the intra-rod passage 50 is blocked. 160 detects that the working fluid has been led from the rod-side chamber 11 and the anti-rod-side chamber 12 to the intra-rod passage 50 through the gap between the stepped
- the hydraulic cylinder 100 further includes an O-ring 70 as an annular sealing member that is compressed between the piston member 30 and the piston rod 20 . It is provided on the side opposite to the stepped portion 23 with the 51 as a boundary.
- the O-ring 70 blocks communication between the rod-side chamber 11 and the anti-rod-side chamber 12 through the piston member 30 and the piston rod 20 .
- the piston member 30 is provided between a piston main body portion 31 that slides along the inner peripheral surface of the cylinder tube 10 and a step portion 23 of the piston rod 20 and the piston main body portion 31, and the rod internal passage 50 is provided. and a ring member 32 that blocks one opening 51 . It has an annular groove 31b which is formed open and accommodates an O-ring 70 .
- the annular groove 31b that accommodates the O-ring 70 is formed in an open end face of the piston body 31 that faces the stepped portion 23 of the piston rod 20 .
- the ring member 32 is provided between the piston main body portion 31 and the stepped portion 23 of the piston rod 20 and the ring member 32 contacts the stepped portion 23, the piston member 30 and the stepped portion 23 of the piston rod 20 are separated from each other. contact area is ensured.
- the piston rod 20 has a small diameter portion 21 formed on the distal end side of the stepped portion 23 and a curved surface portion 24 provided at the boundary between the small diameter portion 21 and the stepped portion 23 and recessed annularly.
- 30 is provided on the inner peripheral surface of the piston member 30 so as to face the curved surface portion 24, and has a tapered portion 32a whose inner diameter increases toward one end surface 33 thereof.
- the curved surface portion 24 of the piston rod 20 suppresses stress concentration occurring at the boundary portion between the small diameter portion 21 and the stepped portion 23 .
- the tapered portion 32a of the piston member 30 prevents contact between the piston member 30 and the curved surface portion 24 of the piston rod 20, contact between the piston member 30 and the stepped portion 23 of the piston rod 20 is ensured.
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Abstract
Description
上記実施形態では、ロッド内通路50に作動油が導かれたことを検知する検知部が圧力センサ60である形態について説明した。これに限らず、検知部は、画像センサや液量センサ等のセンサ160であってもよい。具体的には、ロッド内通路50の開口部52に臨んで、作動油と反応して変色する部材や、作動油との反応や油圧等により形状が変化する部材、作動油を貯留する容器が設けられ、センサ160により、上記部材の変色や、形状変化、容器内の作動油の量を観測することで、ロッド内通路50に作動油が導かれたことを検知する。これらの構成では、圧力センサ以外の画像センサや液量センサ等のセンサ160により、ロッド内通路50に作動油が導かれたことを検知することができる。なお、センサ160ではなく、オペレータの目視により上記部材の変色や、形状変化、容器内の作動油の量を観測してピストン部材30の緩みを認知してもよい。この場合には、ロッド内通路50の開口部52に臨んで設けられる部材や容器自体が検知部となる。
上記実施形態では、ピストン本体部31とピストンロッド20の段部23との間にはリング部材32が設けられ、リング部材32が段部23に接触して両者の間を通じたロッド側室11からロッド内通路50への作動油の流れが遮断される。これに限らず、図3に示すように、リング部材32が設けられず、ピストン本体部31のみでピストン部材30が構成されてもよい。この構成であっても、上記実施形態と同様に、ピストン部材30の緩みに起因する油圧シリンダ100の作動不良を防止することができる。この形態でも、Oリング70は、上記実施形態と同様に、ロッド内通路50の開口部51を境にしてピストンロッド20の段部23とは反対側に設けられる。しかし、Oリング70を収容する環状溝31bは、ピストン本体部31の端面には開口して形成されない。したがって、Oリング70を環状溝31bに収容しづらい。これに対して、上記実施形態では、リング部材32が設けられ、環状溝31bがピストン本体部31の端面に開口するため、Oリング70を環状溝31bに容易に収容することができる。
Claims (4)
- 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内に往復動自在に挿入されるピストンロッドと、
前記ピストンロッドの先端に連結され前記シリンダチューブ内に流体圧室を区画するピストン部材と、
前記ピストンロッド内に設けられ、一方の開口部が前記シリンダチューブ内において前記ピストンロッドの外周面に開口し、他方の開口部が前記シリンダチューブ外で開口するロッド内通路と、
前記シリンダチューブ外に設けられ前記ロッド内通路に作動流体が導かれたことを検知する検知部と、を備え、
前記ピストン部材は、前記ピストンロッドの外周面に設けられる環状の段部に一方の端面が接触し、前記ロッド内通路の前記一方の開口部を遮断した状態で前記ピストンロッドに連結され、
前記検知部は、前記段部と前記ピストン部材との間を通じて前記流体圧室から前記ロッド内通路に作動流体が導かれたことを検知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、
前記ピストン部材と前記ピストンロッドとの間に圧縮されて設けられる環状のシール部材をさらに備え、
前記シール部材は、前記ロッド内通路の前記一方の開口部を境にして前記段部とは反対側に設けられる流体圧シリンダ。 - 請求項2に記載の流体圧シリンダであって、
前記ピストン部材は、
前記シリンダチューブの内周面に沿って摺動するピストン本体部と、
前記ピストン本体部と前記ピストンロッドの前記段部との間に設けられ、前記ロッド内通路の前記一方の開口部を遮断するリング部材と、を有し、
前記ピストン本体部は、内周面に形成されるとともに、前記リング部材を介して前記ピストンロッドの前記段部に対向する端面に開口して形成され、前記シール部材を収容する環状溝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、
前記ピストンロッドは、前記段部よりも先端側に形成される小径部と、前記小径部における前記段部との境界部に設けられ環状に窪む曲面部を有し、
前記ピストン部材は、前記曲面部に対向するように前記ピストン部材の内周面に設けられ、前記一方の端面に向かって内径が大きくなるテーパ部を有する流体圧シリンダ。
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Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5861905U (ja) * | 1981-10-22 | 1983-04-26 | カヤバ工業株式会社 | 油圧シリンダ |
JPS6397491A (ja) * | 1986-10-09 | 1988-04-28 | Sanshin Ind Co Ltd | 船舶推進機の昇降装置 |
JP2004263713A (ja) | 2003-01-29 | 2004-09-24 | Koganei Corp | 流体圧シリンダ |
JP2007092785A (ja) * | 2005-09-27 | 2007-04-12 | Shin Caterpillar Mitsubishi Ltd | シリンダ装置並びにロックナットの緩み及びロッドの伸び変形検知方法 |
JP2010164067A (ja) * | 2009-01-13 | 2010-07-29 | Kayaba Ind Co Ltd | 流体圧シリンダ |
US20200362888A1 (en) * | 2017-11-03 | 2020-11-19 | Ipgate Ag | Piston-cylinder units and hydraulic devices with diagnosis or monitoring function of the control and regulating device |
JP2021123341A (ja) | 2020-01-31 | 2021-08-30 | 東京ライト工業株式会社 | キャップ |
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2021
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- 2022-04-25 CN CN202280052654.1A patent/CN117795207A/zh active Pending
Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5861905U (ja) * | 1981-10-22 | 1983-04-26 | カヤバ工業株式会社 | 油圧シリンダ |
JPS6397491A (ja) * | 1986-10-09 | 1988-04-28 | Sanshin Ind Co Ltd | 船舶推進機の昇降装置 |
JP2004263713A (ja) | 2003-01-29 | 2004-09-24 | Koganei Corp | 流体圧シリンダ |
JP2007092785A (ja) * | 2005-09-27 | 2007-04-12 | Shin Caterpillar Mitsubishi Ltd | シリンダ装置並びにロックナットの緩み及びロッドの伸び変形検知方法 |
JP2010164067A (ja) * | 2009-01-13 | 2010-07-29 | Kayaba Ind Co Ltd | 流体圧シリンダ |
US20200362888A1 (en) * | 2017-11-03 | 2020-11-19 | Ipgate Ag | Piston-cylinder units and hydraulic devices with diagnosis or monitoring function of the control and regulating device |
JP2021123341A (ja) | 2020-01-31 | 2021-08-30 | 東京ライト工業株式会社 | キャップ |
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