JP5464408B2 - Fluid pressure cylinder - Google Patents

Description

  The present invention relates to a fluid pressure cylinder having a piston that is displaceable under a pressure fluid supply action.

  2. Description of the Related Art Conventionally, a fluid pressure cylinder having a piston that is displaced under the action of supplying a pressure fluid has been used as a conveying means for a workpiece or the like.

  In such a fluid pressure cylinder, a hollow cylinder tube into which a pressure fluid is supplied, a head cover that closes one end of the cylinder tube, a piston built in the cylinder tube, and a cylinder tube A rod cover that is attached to the other end and holds the piston rod connected to the piston in a displaceable manner. For example, by supplying a pressure fluid from one port provided in the head cover to the inside of the cylinder tube, the piston is displaced along the axial direction in a state where the piston packing provided on the outer peripheral surface is in sliding contact. On the contrary, by supplying a pressure fluid from the other port provided in the rod cover, the piston is pressed and displaced in the opposite direction (see, for example, Patent Document 1).

JP-A-9-133109

  In the fluid pressure cylinder according to Patent Document 1 as described above, the piston is provided inside the cylinder tube, and the piston packing attached to the piston is displaced while sliding on the inner peripheral surface of the cylinder tube. Therefore, when assembling the piston inside the cylinder tube, it is necessary to accurately match the axis of the cylinder tube and the axis of the piston. In other words, it is necessary to arrange the cylinder tube and the piston coaxially. Therefore, the assembly work between the cylinder tube and the piston becomes complicated, and the number of assembling steps increases, and the machining accuracy applied to the cylinder tube and the piston is required. There exists a problem of causing the increase of a process and cost.

  Similarly, when assembling the head cover and the rod cover to both ends of the cylinder tube, it is necessary to arrange the cylinder tube, the head cover, and the rod cover on the same axis. Man-hours will increase.

  Further, in recent years, there is a demand for reducing the sliding resistance of the piston in the fluid pressure cylinder and driving the piston with a smaller amount of pressure fluid.

  The present invention has been made in consideration of the above-described problems, and provides a fluid pressure cylinder capable of reducing the manufacturing cost, improving the assembling workability, and improving the operability. For the purpose.

In order to achieve the above object, the present invention provides a cylinder tube formed in a hollow shape and having a cylinder chamber therein,
A pair of end blocks that are attached to both ends of the cylinder tube and close the cylinder chamber;
A piston which is provided in the cylinder chamber and is freely displaceable along the axial direction of the cylinder tube;
With
The cylinder tube is formed of an elastically deformable material. When the pressure fluid is supplied into the cylinder chamber, the cylinder tube is deformed radially outward by the pressure of the pressure fluid, and the piston is formed on the inner wall surface of the cylinder tube. The sealing member provided in the outer peripheral surface of this is slidably contacted.

  According to the present invention, the hollow cylinder tube is formed of an elastically deformable material, and a pair of end blocks are respectively attached to both ends of the cylinder tube, so that the cylinder tube is formed inside the cylinder tube. The cylinder chamber in which the piston is displaceable is closed. When the piston is displaced along the cylinder tube by the pressure fluid supplied to the inside of the cylinder chamber, the seal member provided on the outer peripheral surface of the piston is displaced while sliding on the inner wall surface of the cylinder tube.

  Therefore, when the pressure fluid is supplied to the inside of the cylinder tube, the cylinder tube is uniformly pressed radially outward by the pressure of the pressure fluid and deformed into a circular cross section. Can be ensured easily, and contact between the cylinder tube and the seal member provided on the piston can be reliably avoided. As a result, sliding resistance when the piston is displaced along the cylinder tube can be reduced, and the piston can be smoothly displaced. Further, since the sliding resistance of the seal member is reduced, the piston can be displaced with a low pressure.

  In addition, it is not necessary to perform the round processing conventionally performed on the inner peripheral surface of the cylinder tube, and the roundness of the cylinder tube can be easily secured, so that the processing cost can be reduced. It becomes.

  Furthermore, the cylinder tube can be easily positioned by fitting the cylinder tube to the end block, and the cylinder tube can be assembled coaxially with a set of end blocks. Assembling property of the fluid pressure cylinder containing can be improved.

  The cylinder tube may be pressed outward in the radial direction by sliding the seal member. Thereby, the sealing member provided on the outer peripheral surface of the piston and the cylinder tube can be brought into close contact with each other, and the leakage of the pressure fluid from the cylinder chamber through the piston and the cylinder tube can be reliably prevented. In addition, since the cylinder tube has a circular cross section, the sliding resistance when the piston is displaced along the cylinder tube is constant in the circumferential direction of the cylinder tube, and the piston can be smoothly displaced. It becomes.

  Further, by providing a holding means for holding a separation distance between one end block and the other end block between the pair of end blocks, an axis line is formed with respect to the cylinder tube provided between the end blocks. The application of a load in the direction can be avoided, and unintentional deformation of the cylinder tube is prevented.

  Furthermore, the holding means may be a connecting rod that connects one end block and the other end block.

  Furthermore, the holding means may be a cylindrical protective cover that is sandwiched between one end block and the other end block and disposed on the outer peripheral side of the cylinder tube.

  Further, by providing a groove filled with lubricant on the inner wall surface of the cylinder tube, when the seal member provided on the piston is displaced while sliding on the inner wall surface of the cylinder tube, the piston and the cylinder tube Therefore, the piston can be displaced more smoothly.

  Furthermore, unintended deformation of the cylinder tube can be prevented by the protective material by winding the protective material around the outer peripheral surface of the cylinder tube.

  Furthermore, by providing a negative pressure chamber to which negative pressure fluid is supplied on the outer peripheral side of the cylinder tube, the cylinder tube can be suitably sucked in the radially outward direction, so that the cylinder tube is supplied to the inside of the cylinder tube. It is possible to improve the roundness of the cylinder tube together with the pressure fluid.

  Furthermore, by providing a restraining means that can hold the cylinder tube in a deformed cross-sectional shape, it is possible to easily form cylinder tubes having different cross-sectional shapes.

  Further, the restraining means may be composed of a first restraining portion provided on the outer peripheral side of the cylinder tube and a second restraining portion provided on the end block and capable of holding the end portion of the cylinder tube.

  According to the present invention, the following effects can be obtained.

  That is, a hollow cylinder tube is formed in a hollow shape with a material that can be elastically deformed, and a pair of end blocks are respectively attached to both ends of the cylinder tube so that pressure fluid is introduced into the cylinder chamber of the cylinder tube. When supplied, since it can be uniformly pressed radially outward by the pressure fluid pressure and deformed into a circular cross section, the seal member provided on the piston is in sliding contact with the inner peripheral surface of the cylinder tube, The sliding resistance when displacing along the axial direction can be reduced, and the piston can be displaced smoothly. Further, it is not necessary to perform a round process on the inner wall surface of the cylinder tube, and it is possible to reduce the processing cost, and it is easy by fitting the cylinder tube to a set of end blocks. In addition, since the cylinder tube can be positioned, the assembling property of the fluid pressure cylinder including the cylinder tube can be improved.

1 is an external perspective view of a fluid pressure cylinder according to a first embodiment of the present invention. FIG. 2 is an overall cross-sectional view of the fluid pressure cylinder shown in FIG. 1. It is an expanded sectional view which shows the piston vicinity of FIG. It is sectional drawing along the IV-IV line of FIG. It is an expanded sectional view of the fluid pressure cylinder concerning the 1st modification in which the lubrication groove was provided in the inner peripheral surface of a tube. It is an expanded sectional view of the fluid pressure cylinder which concerns on the 2nd modification with which the outer peripheral surface of the tube was equipped with the protective material. It is a whole sectional view of a fluid pressure cylinder concerning a 2nd embodiment of the present invention. It is a whole sectional view of a fluid pressure cylinder concerning a 3rd embodiment of the present invention. It is sectional drawing along the IX-IX line of FIG. FIG. 10 is a partially omitted external perspective view of a fluid pressure cylinder according to a fourth embodiment of the present invention. It is a disassembled perspective view of the fluid pressure cylinder shown in FIG. It is sectional drawing along the XII-XII line | wire of FIG. FIG. 13A is a cross-sectional view of a restraint member according to a modified example having a restraint hole having an oval cross section, and FIG. 13B is a cross-sectional view of the restraint member according to a variant having a restraint hole having a square cross section. .

  A preferred embodiment of a fluid pressure cylinder according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 indicates a fluid pressure cylinder according to the first embodiment of the present invention.

  As shown in FIGS. 1 to 3, the fluid pressure cylinder 10 includes a tube (cylinder tube) 12 formed in a cylindrical shape, a head cover (end block) 14 attached to one end of the tube 12, and A rod cover (end block) 16 attached to the other end of the tube 12, a piston 18 displacing the inside of the tube 12 along the axial direction (arrows A and B directions), and the tube 12 are interposed. A plurality of connecting rods 20 for connecting the head cover 14 and the rod cover 16 to each other. The head cover 14 and the rod cover 16 are arranged on a straight line so as to face each other together with the tube 12.

  The tube 12 is, for example, a cylindrical body that is formed from a thin plate-like metal material in a circular cross section and is elastically deformable in the radial direction. The tube 12 has a substantially constant diameter and a constant thickness and extends in the axial direction (the directions of arrows A and B). One end of the tube 12 is an inlay portion 26 (described later) formed on the end surface of the head cover 14. While being fitted, the other end is fitted to an inlay portion 36 (described later) provided on the end surface of the rod cover 16. As a result, the center of the tube 12 is positioned so as to be coaxial with the axis of the head cover 14 and the rod cover 16, and a sealed cylinder chamber 22 is formed.

  By configuring the tube 12 with, for example, a seamless tube or a microplasma welded tube, it becomes possible to ensure the surface roughness of the inner peripheral surface 12a of the tube 12, and with respect to the inner peripheral surface 12a. It is preferable that there is no need for a separate finishing process. As a result, the manufacturing process of the fluid pressure cylinder 10 including the tube 12 can be shortened, and the manufacturing cost can be reduced.

  The head cover 14 is made of, for example, a block body having a substantially rectangular cross section formed by casting, and includes a first port 23 through which pressure fluid is supplied and discharged, and a first rod hole 24 into which a piston rod 40 described later is inserted. And an inlay portion 26 into which one end portion of the tube 12 is fitted. The first rod hole 24 is formed in the center portion of the head cover 14 and is open to the rod cover 16 side (arrow A direction) and communicates with the first port 23 opened to the side portion.

  The inlay portion 26 protrudes from the end of the head cover 14 in a circular shape, and is formed in a tapered shape whose outer peripheral surface gradually decreases in the direction away from the end (direction of arrow A in FIG. 2). Is done. Specifically, the inlay portion 26 is a draft provided to take out a cast product from the mold when the head cover 14 is manufactured by die casting such as die casting.

  Further, a first rod hole 24 penetrates along the axial direction in the center of the inlay portion 26, and a cushion packing 28 is provided in the first rod hole 24 via an annular groove on the inner peripheral surface. Yes.

  Furthermore, the head cover 14 is formed with a plurality of (for example, four) first hole portions 30 (see FIG. 4) through which the connecting rods 20 are inserted at positions corresponding to the four corners thereof, and penetrates along the axial direction. ing.

  Similarly to the head cover 14, the rod cover 16 is formed of, for example, a block body having a substantially rectangular cross section formed by casting, and a second port 32 through which pressure fluid is supplied / discharged and a piston rod 40 to be described later are inserted. The second rod hole 34, the spigot part 36 into which the end of the tube 12 is fitted, and the second hole part 38 through which the connecting rod 20 is inserted. The second rod hole 34 is formed in the central portion of the rod cover 16 and penetrates along the axial direction. The second rod hole 34 communicates with the second port 32 opened in the side portion, and the inlay portion 36 side (arrow B direction) is It is formed by expanding in the radially outward direction.

  Further, a bushing 42 that supports the piston rod 40 and a rod packing 44 that prevents leakage of pressure fluid through the piston rod 40 are provided on the inner peripheral surface of the second rod hole 34 via an annular groove. Each is provided.

  On the other hand, the spigot portion 36 protrudes from the end portion of the rod cover 16 in a circular shape, and the outer peripheral surface gradually decreases in diameter in a direction away from the end portion (in the direction of arrow B in FIG. 2). It is formed into a shape. Specifically, the inlay portion 36 is a draft provided to take out a cast product from the die when the rod cover 16 is manufactured by die casting such as die casting, like the above-described inlay portion 26. .

  A second rod hole 34 penetrates along the axial direction in the center of the inlay portion 36, and a cushion packing 46 is provided in the second rod hole 34 via an annular groove on the inner peripheral surface. Yes.

  Further, the rod cover 16 is formed with a plurality of (for example, four) second holes 38 through which the connecting rod 20 is inserted at positions corresponding to the four corners thereof, and penetrates along the axial direction.

  The head cover 14 and the rod cover 16 are arranged so that the inlay portions 26 and 36 face each other, and annular seal rings 50a and 50b are mounted on the outer peripheral surfaces of the inlay portions 26 and 36, respectively. The seal rings 50 a and 50 b abut against the inner peripheral surface 12 a of the tube 12 fitted to the spigot portions 26 and 36 to keep the cylinder chamber 22 airtight.

  In addition, when the pressure fluid is supplied to the first port 23 of the head cover 14 and the second port 32 of the rod cover 16, the pressure fluid is introduced into the tube 12 through the first rod hole 24 and the second rod hole 34. Is supplied.

  For example, the four connecting rods 20 are formed of a shaft body having a predetermined length, and are formed on the thick shaft portion 52 and both ends of the thick shaft portion 52, and are engraved with screws on the outer peripheral surface. It consists of a pair of thin shaft portions 54. The thin shaft portion 54 is formed with a diameter that can be inserted into the first hole portion 30 of the head cover 14 and the second hole portion 38 of the rod cover 16.

  The connecting rod 20 has a thin shaft portion 54 on one end side inserted into the first hole 30 of the head cover 14 and a thin shaft portion 54 on the other end side inserted into the second hole 38 of the rod cover 16. After that, a washer 56 is inserted into each of the thin shaft portions 54 and a nut 58 is screwed together.

  Thereby, the head cover 14 and the rod cover 16 are connected by the connecting rod 20 so as to sandwich the tube 12.

  Specifically, the end surfaces of the head cover 14 and the rod cover 16 abut against the end of the thick shaft portion 52 of the connecting rod 20 and are screwed into the connecting rod 20 in a state where movement in the direction approaching each other is restricted. The nut 58 is fixed. As a result, the head cover 14 and the rod cover 16 are fixed to each other in a state in which the displacement in the axial direction is restricted with respect to the connecting rod 20, so that the fluid pressure cylinder 10 is formed by the head cover 14, the rod cover 16 and the connecting rod 20. Rigidity along the axial direction (arrows A and B directions) is ensured, and a load along the axial direction is applied to the tube 12 provided between the head cover 14 and the rod cover 16. It is avoided.

  In other words, the connecting rod 20 is provided for the purpose of preventing the load from being applied to the elastically deformable tube 12 when a load along the axial direction is applied to the fluid pressure cylinder 10. It has been.

  The piston 18 is formed in a circular cross section, and at the center thereof, one end portion of the piston rod 40 is inserted through a through hole, and the protrusions provided on both end surfaces of the piston 18 are deformed radially inward. The piston rod 40 is caulked and fixed integrally.

  On the other hand, a wear ring 60, a magnet 62, and a piston packing (seal member) 64 are provided on the outer peripheral surface of the piston 18 via an annular groove. The wear ring 60, the magnet 62, and the piston packing 64 are arranged at a predetermined distance from each other along the axial direction (arrow A, B direction) of the piston 18. Specifically, the wear ring 60 is provided so as to be closest to the head cover 14 (arrow B direction), the piston packing 64 is provided so as to be closest to the rod cover 16 (arrow A direction), and the magnet 62 is It is provided so as to be between the wear ring 60 and the piston packing 64.

  The piston packing 64 is in sliding contact with the inner peripheral surface 12a of the tube 12, and the cylinder chamber 22 provided in the tube 12 is divided into two by the piston 18, and the air tightness in the cylinder chamber 22 is maintained. Further, the outer peripheral diameter of the piston packing 64 is set to be larger than the outer peripheral surface of the piston 18 and slightly larger than the inner peripheral diameter of the tube 12.

  In the piston rod 40, the piston 18 is fixed to one end (arrow B direction), and the other end (arrow A direction) is supported by the rod cover 16 so as to be displaceable. Cylindrical first and second cushion rings 66 and 68 are mounted in the vicinity of one end of the piston 18 so as to cover the outer peripheral surface.

  The first cushion ring 66 is provided at a position on the head cover 14 side (arrow B direction) with respect to the piston 18, and is provided so as to be inserted into the first rod hole 24 under the displacement action of the piston 18. When the piston rod 40 is displaced together with the piston 18 toward the head cover 14 (in the direction of arrow B), the cushion packing 28 comes into sliding contact with the outer peripheral surface of the first cushion ring 66.

  The second cushion ring 68 is provided at a position on the rod cover 16 side (arrow A direction) with respect to the piston 18 and is provided so as to be inserted into the second rod hole 34 under the displacement action of the piston 18. When the piston rod 40 is displaced together with the piston 18 to the rod cover 16 side (arrow A direction), the cushion packing 46 comes into sliding contact with the outer peripheral surface of the second cushion ring 68. That is, the first cushion ring 66 and the second cushion ring 68 are provided along the piston rod 40 so as to be coaxial with the piston 18 in between.

  The fluid pressure cylinder 10 according to the first embodiment of the present invention is basically configured as described above. Next, the operation and action and effects thereof will be described. The state where the piston 18 is displaced toward the head cover 14 (arrow B direction) and the first cushion ring 66 is accommodated in the first rod hole 24 will be described as an initial position.

  First, a pressure fluid supply source (not shown) is connected to the first port 23 via a pipe, and the pressure fluid is supplied to the first port 23 so that the pressure fluid passes through the first rod hole 24 to the inside of the tube 12. Is introduced to one side of the cylinder chamber 22 and presses the end surface of the piston 18 on the head cover 14 side, thereby displacing the piston 18 toward the rod cover 16 (in the direction of arrow A). At this time, the second port 32 is kept open to the atmosphere.

  At this time, as shown in FIG. 4, the tube 12 is uniformly pressed radially outward by the pressure P of the pressurized fluid introduced into the cylinder chamber 22, and the tube 12 is elastically deformed to have a circular cross section. . Thereby, the piston 18 having a circular cross section can be smoothly displaced along the tube 12 having a perfect circular cross section. That is, by making the tube 12 a tubular body made of a thin plate material that can be elastically deformed in the radial direction, the tube 12 is uniformly deformed radially outward by the pressure P of the pressure fluid introduced into the tube 12. It can be a perfect circle. As a result, it is possible to eliminate the need for round processing that has been conventionally performed on the inner peripheral surface of the tube.

  Also, the piston packing 64 provided on the outer peripheral surface of the piston 18 is in sliding contact with the inner peripheral surface 12a of the tube 12, and is displaced together with the piston 18 while pressing the tube 12 slightly outward in the radial direction. As a result, the piston packing 64 and the tube 12 are brought into close contact with each other, so that leakage of the pressure fluid through the piston packing 64 and the inner peripheral surface 12a of the tube 12 is reliably prevented, and the airtightness in the cylinder chamber 22 is maintained. The

  In this way, when the pressure fluid is supplied from the first port 23 to the inside of the tube 12, the piston 18 is displaced toward the rod cover 16 side (arrow A direction) under the pressing action of the pressure fluid, and the piston The rod 40 is a displacement end position where the rod 40 protrudes outside the rod cover 16.

  Next, the pressure fluid supplied to the first port 23 is supplied to the second port 32 under the switching action of a switching valve (not shown), so that the pressure fluid passes through the second rod hole 34 to the cylinder chamber 22. And the end surface of the piston 18 on the rod cover 16 side is pressed to displace the piston 18 toward the head cover 14 (in the direction of arrow B). At this time, the first port 23 is kept open to the atmosphere.

  In this case as well, the tube 12 is equally pressed outward in the radial direction by the pressure fluid introduced into the cylinder chamber 22, and the tube 12 is elastically deformed to have a circular cross section. Thereby, the piston 18 having a circular cross section can be smoothly displaced along the tube 12 having a perfect circular cross section. Further, the piston packing 64 provided on the outer peripheral surface of the piston 18 contacts the inner peripheral surface 12a of the tube 12 and is displaced together with the piston 18 while slightly pressing the tube 12 radially outward. The packing 64 and the tube 12 are brought into close contact with each other, and leakage of the pressure fluid through the space between the piston packing 64 and the inner peripheral surface 12a of the tube 12 is reliably prevented.

  As described above, in the first embodiment, the cylindrical tube 12 made of an elastically deformable thin plate material is provided between the head cover 14 and the rod cover 16, and the piston 18 is displaced inside the tube 12. It is provided freely. When the pressure fluid is introduced into the tube 12 and the piston 18 is pressed and displaced along the tube 12, the tube 12 is evenly pressed radially outwardly by the pressure of the pressure fluid, and the cross section is a perfect circle. Therefore, when the piston 18 is displaced, the piston 18 can be prevented from hitting the piston packing 64 provided on the piston 18 having a circular cross section that displaces the inside of the tube 12. It is possible to reduce the sliding resistance.

  As a result, the piston 18 can be smoothly displaced along the tube 12. That is, the piston 18 can be smoothly displaced even when the pressure fluid supplied is low by reducing the sliding resistance with the piston packing 64 mounted on the outer peripheral surface of the piston 18 (at the time of low pressure). it can.

  In addition, since the tube 12 can be deformed by using the pressure of the supplied pressurized fluid to have a circular shape in cross section, a round process (for example, a cutting process) conventionally applied to the inner peripheral surface of the cylinder tube is possible. ) And the roundness of the inner peripheral surface 12a of the tube 12 can be easily ensured, so that the processing cost can be reduced.

  Furthermore, the tube 12 can be easily positioned by fitting both ends of the tube 12 to the spigot portions 26 and 36 in the head cover 14 and the rod cover 16, and the tube 12 can be positioned in the head cover 14 and the rod cover. 16 can be assembled on the same axis. That is, it is possible to improve the assembling property of the tube 12 with respect to the head cover 14 and the rod cover 16.

  Furthermore, the inlay portions 26 and 36 of the head cover 14 and the rod cover 16 do not need to be processed again in order to fit the tube 12, and are formed, for example, when the head cover 14 and the rod cover 16 are manufactured by molding. The tube 12 can be positioned reliably and easily by using the draft angle of the inlay portions 26 and 36. As a result, the manufacturing process of the fluid pressure cylinder 10 including the head cover 14 and the rod cover 16 can be shortened and the manufacturing cost can be reduced.

  Further, the axial rigidity of the fluid pressure cylinder 10 can be reliably and stably ensured by the plurality of connecting rods 20 that hold the head cover 14 and the rod cover 16 apart from each other by a predetermined distance. In contrast, an axial load is avoided. That is, the fluid pressure cylinder 10 is configured to ensure rigidity by the connecting rod 20 and to ensure airtightness in the cylinder chamber 22 by the tube 12.

  Further, since the tube 12 is uniformly pressed radially outward by the pressure fluid and has a perfect cross section, the pressing force in the radially inward direction against the piston packing 64 slidably contacting the tube 12 is applied to the piston packing 64. Can be equalized in the circumferential direction. As a result, the sliding resistance when the piston 18 is displaced is reduced compared with the conventional fluid pressure cylinder that has been subjected to the circular machining applied to the inner peripheral surface of the cylinder tube, and the piston 18 is smoothly moved. It can be driven.

  Further, as shown in FIG. 5, a lubricating groove (groove portion) 80 that is slightly depressed in the radially outward direction may be provided on the inner peripheral surface 12 a of the tube 12 constituting the fluid pressure cylinder 10 described above. The lubrication groove 80 is composed of, for example, a plurality of annular grooves spaced at equal intervals along the axial direction of the tube 12, and the inside thereof is filled with a lubricant 82 such as grease. Thereby, when the piston 18 is displaced along the tube 12 in the axial direction, the outer peripheral surface of the piston 18 faces the lubricant 82 of the lubricating groove 80, so that the lubricant 82 adheres to the outer peripheral surface. In addition, lubrication between the piston 18 and the tube 12 is suitably performed. As a result, the piston 18 can be displaced more smoothly along the tube 12.

  Furthermore, as shown in FIG. 6, a protective material 90 may be wound around the outer peripheral surface of the tube 12 to increase the rigidity of the tube 12. For example, the protective material 90 is formed in a sheet shape from resin, rubber, carbon fiber, or the like, and is wound around the outer peripheral surface of the tube 12 so as to have a predetermined thickness. The thickness of the protective material 90 is set to a thickness that does not affect the elastic deformation of the tube 12. Thereby, compared with the case where the protective material 90 is not mounted, the rigidity of the tube 12 can be reliably and easily improved.

  Next, a fluid pressure cylinder 100 according to a second embodiment is shown in FIG. The same components as those of the fluid pressure cylinder 10 according to the first embodiment described above are denoted by the same reference numerals, and detailed description thereof is omitted.

  The fluid pressure cylinder 100 according to the second embodiment differs from the fluid pressure cylinder 10 according to the first embodiment in that a cylindrical protective cover 102 is provided so as to cover the outside of the tube 12. doing.

  The protective cover 102 is formed, for example, in a cylindrical shape from a metal material, and the diameter thereof is set larger than the diameter of the tube 12 and is thicker than the thickness of the tube 12. The protective cover 102 is provided so as to be spaced apart from the tube 12 at an equal interval in the radially outward direction.

  Further, both ends of the protective cover 102 are engaged with stepped portions 104 a and 104 b provided on the end surfaces of the head cover 14 and the rod cover 16, respectively. The protective cover 102 is pulled between the head cover 14 and the rod cover 16 by being pulled in a direction in which the head cover 14 and the rod cover 16 approach each other by the connecting rod 20.

  That is, by interposing the protective cover 102 between the head cover 14 and the rod cover 16, it is possible to ensure the rigidity of the fluid pressure cylinder 10 in the axial direction (directions of arrows A and B). As a result, it is avoided that a load in the axial direction is applied from the head cover 14 and the rod cover 16 to the tube 12 formed in a cylindrical shape with a thin plate material, and the deformation of the tube 12 due to the load is surely prevented. can do.

  In other words, the fluid pressure cylinder 10 is configured such that the rigidity in the axial direction can be secured by the protective cover 102 instead of the connecting rod 20.

  Further, since the protective cover 102 is provided on the outer peripheral side of the tube 12, for example, even when another device or the like comes into contact with the fluid pressure cylinder 100, the tube 12 made of a thin plate material is surely secured by the protective cover 102. Therefore, failure of the fluid pressure cylinder 100 can be avoided, and the fluid pressure cylinder 100 can be operated without any problem.

  Next, a fluid pressure cylinder 150 according to a third embodiment is shown in FIGS. In addition, the same referential mark is attached | subjected to the component same as the fluid pressure cylinders 10 and 100 which concern on 1st and 2nd embodiment mentioned above, and the detailed description is abbreviate | omitted.

  In the fluid pressure cylinder 150 according to the third embodiment, a negative pressure supply chamber (negative pressure chamber) 152 to which a negative pressure fluid is supplied is provided between the tube 12 and the protective cover 102. This is different from the fluid pressure cylinder 100 according to the second embodiment.

  In the fluid pressure cylinder 150, a negative pressure supply chamber 152 having a predetermined radial distance is provided between the tube 12 and the protective cover 102, and a negative pressure fluid for supplying a negative pressure fluid to the negative pressure supply chamber 152 is provided. A pressure port 154 is provided. A piping 156 to which a negative pressure fluid is supplied is connected to the negative pressure port 154.

  Then, by supplying a negative pressure fluid from a negative pressure supply device (not shown) to the negative pressure supply chamber 152 in advance through the pipe 156 and the negative pressure port 154, for example, the piston 18 is subjected to a load applied to the piston rod 40. Even when the tube 12 is displaced and a negative pressure is generated in the tube 12, the tube 12 is pulled in the radially outward direction at a predetermined pressure by the negative pressure fluid in advance, so that the tube 12 is deformed in the radially inward direction. Is prevented. In other words, when a negative pressure is generated inside the tube 12, it is possible to reliably prevent the tube 12 from buckling radially inward.

  Further, in addition to pressing the tube 12 from the inside in the radial outward direction with the pressure fluid to make a perfect circular cross section, the outer periphery of the tube 12 is pulled in the radial outward direction with the negative pressure fluid to thereby form the tube 12. It is possible to further improve the roundness.

  Instead of supplying the negative pressure fluid to the negative pressure supply chamber 152 through the negative pressure port 154 described above, a relief valve (not shown) that communicates with the outside air when the pressure in the tube 12 is reduced is provided. It may be. Thereby, even when the inside of the tube 12 becomes negative pressure, since the outside air (atmosphere) can be introduced into the tube 12 through the relief valve, the tube 12 is deformed radially inward under the action of negative pressure. Can be prevented.

  Next, a fluid pressure cylinder 200 according to a fourth embodiment is shown in FIGS. In addition, the same referential mark is attached | subjected to the component same as the fluid pressure cylinder 10,100,150 which concerns on the 1st-3rd embodiment mentioned above, and the detailed description is abbreviate | omitted.

  In the fluid pressure cylinder 200 according to the fourth embodiment, instead of the protective cover 102 described above, a restraining member (first restraining portion) 202 that can be held in a state where the cross-sectional shape of the tube 12 is elastically deformed is provided. This is different from the fluid pressure cylinder 150 according to the third embodiment.

  In the fluid pressure cylinder 200, an inlay portion (second constraining portion) 204a of the head cover 204 is formed in a substantially triangular cross section, and an inlay portion (second constraining portion) 206a of the rod cover 206 is also substantially in cross section. It is formed in a triangular shape. The inlay portions 204a and 206a are formed so as to be symmetrical with respect to the tube 12 disposed between the head cover 204 and the rod cover 206, and the outer peripheral lengths of the inlay portions 204a and 206a It is formed so as to be equivalent to the inner peripheral length. The restraining member 202 and the inlay portions 204a and 206a described above function as restraining means that can deform and hold the sectional shape of the tube 12 freely.

  That is, when the head cover 204 and the rod cover 206 are assembled to the tube 12, both end portions of the tube 12 are inserted into the inlay portions 204a and 206a, respectively, so that both end portions are elastically deformed into a substantially triangular cross section. The parts 204a and 206a are fitted. In other words, both end portions of the tube 12 are elastically deformed so as to follow the cross-sectional shape of the spigot portions 204a and 206a.

  The constraining member 202 is formed, for example, in a symmetrical shape and is composed of a pair of first and second block bodies 208 and 210 that can be divided, and the central portion thereof has the same shape as the cross-sectional shape of the inlay portions 204a and 206a. A constraining hole 212 having a substantially triangular cross section is formed. That is, by dividing the first block body 208 and the second block body 210, the constraining hole 212 formed therein is divided into two equal parts. The constraining hole 212 is formed so that its inner peripheral length is equal to the outer peripheral length of the tube 12.

  A fixing bolt 216 is inserted into the first block body 208 through a bolt hole 214 penetrating from the side in the horizontal direction, and the second block body 210 is connected to the bolt hole 214 of the first block body 208. A screw hole 218 penetrates in a horizontal direction at a position on a straight line. Then, the first block body 208 and the second block body 210 are joined, and the fixing bolt 216 inserted through the bolt hole 214 is screwed into the screw hole 218 of the second block body 210, whereby the first block The body 208 and the second block body 210 are connected to each other around the restraint hole 212.

  The restraining member 202 is installed in the vicinity of the substantially central portion of the tube 12 between the head cover 204 and the rod cover 206, and the first block body 208 and the second block body 210 approach each other around the tube 12. Then, after being sandwiched via the restraining hole 212, it is fixed to the tube 12 by being connected with a fixing bolt 216.

  At this time, the cross-sectional shape of the tube 12 is forcibly pressed along the inner peripheral surface of the constraining hole 212 formed in a triangular cross section and deformed into a triangular cross section.

  In this case, the piston 220 provided inside the tube 12 is also formed in a triangular cross section corresponding to the cross sectional shapes of the head cover 204 and the inlay portions 204a and 206a of the rod cover 206 and the restraining hole 212 of the restraining member 202. .

  Thus, the tube 12 formed into a circular cross section with a thin plate can be deformed into a triangular cross section by the head portions 204a and 206a of the rod cover 206 and the constraining holes 212 of the constraining member 202. It is possible to configure the fluid pressure cylinder 200 having various cross-sectional shapes by the tube 12 having a general circular cross section and elastically deformable without separately preparing tubes having different shapes.

  Further, the cross-sectional shape of the restraint hole 212 and the spigot portions 204a and 206a in the restraint member 202 described above is not limited to the case where the cross-sectional shape is formed in a triangular cross section. For example, as shown in FIG. A constraining member 202a provided with a constraining hole 212a having an elliptical cross section having a long axis and an inlay portion may be employed, or a constraining hole 212b having a substantially rectangular cross section may be provided as shown in FIG. 13B. Alternatively, the restraining member 202b and the spigot portion may be employed. In any of the cases described above, the pistons 220a and 220b have a cross-sectional shape corresponding to the cross-sectional shapes of the restraining holes 212a and 212b and the inlay portion, and the inner peripheral length of the restraining holes 212a and 212b is Set to match the outer perimeter.

  Furthermore, for example, when a fluid pressure cylinder is configured using a tube having a short longitudinal dimension, the both ends of the tube are held by a head cover and a rod cover having an inlay portion, thereby forming a non-circular cross section. It is also possible to change the cross-sectional shape of the tube without using a restraining member as described above by the inlay portion.

  In addition, the fluid pressure cylinder according to the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted without departing from the gist of the present invention.

10, 100, 150, 200 ... Fluid pressure cylinder 12 ... Tube 14, 204 ... Head cover 16, 206 ... Rod cover 18, 220, 220a, 220b ... Piston 20 ... Connecting rod 22 ... Cylinder chamber 26, 36, 204a, 206a ... Inner part 40 ... piston rod 64 ... piston packing 80 ... lubricant groove 82 ... lubricant 90 ... protective material 102 ... protective cover 152 ... negative pressure supply chamber 154 ... negative pressure port 202 ... restraining member 208 ... first block body 210 ... first 2-block body 212, 212a, 212b ... Restraint hole

Claims (6)

A cylinder tube formed in a hollow shape and having a cylinder chamber therein;
A pair of end blocks that are attached to both ends of the cylinder tube and close the cylinder chamber;
A piston which is provided in the cylinder chamber and is freely displaceable along the axial direction of the cylinder tube;
With
The cylinder tube is formed of an elastically deformable material. When the pressure fluid is supplied into the cylinder chamber, the cylinder tube is deformed radially outward by the pressure of the pressure fluid , and the piston tube is formed on the inner wall surface of the cylinder tube. A seal member provided on the outer peripheral surface is slidably contacted , and the cylinder tube is pressed radially outward when the seal member is slidably contacted, and one end block and the other are interposed between the pair of end blocks. provided holding means for holding the distance between the end blocks of, wherein the outer periphery of the cylinder tube, a fluid pressure cylinder, wherein Rukoto negative pressure chamber is provided which is supplied a negative pressure fluid. A cylinder tube formed in a hollow shape and having a cylinder chamber therein;
A pair of end blocks that are attached to both ends of the cylinder tube and close the cylinder chamber;
A piston which is provided in the cylinder chamber and is freely displaceable along the axial direction of the cylinder tube;
With
The cylinder tube is formed of an elastically deformable material. When the pressure fluid is supplied into the cylinder chamber, the cylinder tube is deformed radially outward by the pressure of the pressure fluid , and the piston tube is formed on the inner wall surface of the cylinder tube. A seal member provided on the outer peripheral surface is slidably contacted , and the cylinder tube is pressed radially outward when the seal member is slidably contacted, and one end block and the other are interposed between the pair of end blocks. The holding means for holding the separation distance from the end block is provided, and the holding means can be held in a state where the cross-sectional shape of the cylinder tube is deformed, and the holding means is provided on the outer peripheral side of the cylinder tube. a first restricting portion provided, that having a second restricting portion capable of holding an end portion of the cylinder tube is provided on the end block Fluid pressure cylinder, wherein the door. The fluid pressure cylinder according to claim 1 or 2 ,
The fluid pressure cylinder according to claim 1, wherein the holding means is a connecting rod that connects the one end block and the other end block. The fluid pressure cylinder according to claim 1 or 2 ,
The fluid pressure cylinder according to claim 1, wherein the holding means is a cylindrical protective cover that is sandwiched between the one end block and the other end block and disposed on an outer peripheral side of the cylinder tube. In the fluid pressure cylinder according to any one of claims 1 to 4 ,
The fluid pressure cylinder according to claim 1, wherein a groove filled with a lubricant is provided on an inner wall surface of the cylinder tube. In the fluid pressure cylinder according to any one of claims 1 to 5 ,
A fluid pressure cylinder, wherein a protective material is wound around an outer peripheral surface of the cylinder tube.

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