JP2006076231A - Sealing ring, method and apparatus for molding sealing ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing ring which makes a burr, if it is formed, be formed at a position preventing a seal position from being affected adversely, a method for molding the sealing ring, and an apparatus for the method. <P>SOLUTION: In the sealing ring in which linear burrs are left in the circumference direction on the periphery and/or the interior of a sealing ring main body 7b during compression molding, the burr is left at a peripheral position separated from the minimum inside diameter part B and the maximum outside diameter part A of the sealing ring main body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a seal ring that is used in a shaft seal mechanism to prevent fluid or gas leakage and a molding method and molding apparatus thereof, and more particularly to an inner circumference of a rod guide of an oil / pneumatic cylinder or a hydraulic shock absorber, a cylinder The present invention relates to a seal ring disposed on an inner periphery or an outer periphery of a piston, a molding method thereof, and a molding apparatus.

  Generally, a shaft sealing mechanism of an oil / pneumatic cylinder or a hydraulic shock absorber, for example, a seal made of an O-ring formed of a rubber material or an elastic synthetic resin between a rod guide and a piston rod and between the cylinder and the piston. A ring is interposed to prevent fluid and gas in the cylinder from leaking outside.

  As a method for molding this seal ring, for example, the one disclosed in Patent Document 1 has been developed. A mold as a molding device used in this molding method is shown in FIGS. 9A and 9B. Things are common.

  That is, the basis of this molding apparatus is composed of a pair of upper and lower molds 1 and 2 as shown in FIG. 9A, which are opposed to each other in the middle of horizontal split surfaces 3 and 4 of the molds 1 and 2, respectively. A cavity CV composed of annular grooves 5 and 6 is formed.

  In actual use, as shown in FIG. 9B, it is normal that annular grooves 8 and 8 are disposed on both sides of each cavity CV.

  When the seal ring 7 is compression-molded using the molds 1 and 2, a molding material made of rubber or elastic synthetic resin is weighed and loaded into the heated cavities CV of the molds 1 and 2. Then, the material is heated and pressurized to be cured while matching the molten state of the material in the cavity CV.

In this case, the molding material is in a fluid state in the cavity CV and is filled up everywhere, at which time a chemical reaction occurs and hardens. After the molds 1 and 2 are kept closed for an appropriate time, the molds 1 and 2 are opened and the seal ring 7 as a molded product is taken out. At this time, the excess material flows into the grooves 8 and 8 for disposal, and streaks of burrs remain between the split surfaces 3 and 4. Are taken out together, and then burrs and scraps are cut.
Japanese Patent Laid-Open No. 58-38139 (FIG. 9)

  As shown in FIGS. 10A and 10B, the seal ring 7 obtained by compression molding using the molds 1 and 2 comprises an annular seal ring body 7b. Then, as shown in FIG. 10C, burrs 7a are formed as annular protrusions on the outer circumference and the inner circumference in the diameter direction of the seal ring main body 7b.

  In the burrs 7a and 7a, as described above, a part of the material flows in the discarding grooves 8 and 8 during molding, and the gaps 3 and 4 are slightly opened by the pressure applied to the material. It occurs because it leaks and hardens as it is.

  Since this burr is difficult to cut precisely in post-processing, it is attached to the shaft seal mechanism while remaining slightly.

  For example, as shown in FIG. 11, in an oil / pneumatic cylinder or hydraulic shock absorber in which a piston rod 11 is movably inserted into a cylinder 9 via a piston 10, a seal ring 7 is placed in an outer circumferential annular groove 12 of the piston 10. The burr 7a on the outer peripheral side of the seal ring main body 7b is in sliding contact with the inner periphery of the cylinder 9.

  For this reason, local high surface pressure by the burr 7a is generated on the cylinder 9 to increase the friction, which becomes a sliding resistance and adversely affects the stroke of the piston 10.

  Further, when the burr 7a is deformed by the internal pressure or the burr 7a is deformed after being used for a long period of time, a gap is generated between the cylinder 9 and fluid or gas leakage is induced.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a seal ring, a molding method, and a molding apparatus that generate the burr at a position that does not adversely affect the seal position even if a burr is formed.

  In order to achieve the above object, the seal ring of the present invention is a seal in which streak burrs remain along the circumferential direction on the outer periphery, inner periphery, or both outer periphery and inner periphery of the seal ring body during compression molding. The ring is characterized in that burrs are left in the circumferential surface positions apart from the minimum inner diameter portion and the maximum outer diameter portion of the seal ring main body.

  Similarly, the seal ring molding method is such that a semicircular annular groove formed on each split surface of a pair of upper and lower molds is opposed to each other to form an annular cavity, and a molding material is inserted into the cavity. In the molding method of the seal ring in which the molding material is cured by heating and pressurizing while matching the timing with the molten state, each of the split surfaces is formed at a position away from the minimum inner diameter portion and the maximum outer diameter portion of the cavity, When pressurizing each mold, streak-like burrs generated along the circumferential direction between the above-mentioned split faces are generated at positions on the peripheral surface away from the minimum inner diameter part and the maximum outer diameter part of the seal ring body. Features.

  Similarly, the seal ring molding apparatus is composed of a pair of upper and lower molds, and each annular face formed on each split surface of each mold is opposed to each other to form an annular cavity, and molding is performed in the cavity. In a sealing ring molding apparatus that inserts material and heats and presses to cure the molding material while matching the molten state of the molding material, the split surface is separated from the minimum inner diameter portion and the maximum outer diameter portion of the cavity. It was formed in the position.

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

1) Since the seal ring according to the present invention has burrs remaining in the circumferential surface positions away from the minimum inner diameter portion and the maximum outer diameter portion of the seal ring main body, the seal ring is interposed in the clearance of the shaft seal device. At this time, this burr is located away from the mating member with which the seal ring main body is slidably contacted, and there is no fear of increasing the sliding resistance against the mating member, and it is possible to prevent the occurrence of fluid and gas leakage due to the deformation of the burr.

2) Similarly, in the sealing ring molding method and molding apparatus of the present invention, the split surface of the mold is formed at a position away from the innermost diameter portion and the outermost diameter portion of the cavity. The burr due to the molding material leaking into the surface can be generated at a position apart from the minimum inner diameter portion and the maximum outer diameter portion of the main body of the obtained seal ring. Therefore, this burr does not adversely affect the sealing function of the shaft seal mechanism as described above.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIGS. 1 to 8 show embodiments for carrying out a molding method for molding the seal ring 7 of the present invention. In addition, what has the same function attaches | subjects and demonstrates the same code | symbol in each figure.

  The molded seal ring 7 has a streak-like burr 7a remaining along the circumferential direction on the outer periphery, the inner periphery, or both of the seal ring main body 7b and the seal ring main body 7b as in the prior art. The generation position is different from the conventional one.

  That is, the seal ring 7 such as an O-ring according to the present invention is a seal ring in which burrs 7a remain on the outer periphery, the inner periphery, or both the outer periphery and the inner periphery of the seal ring seal ring body 7b during compression molding. The burr 7a remains in the circumferential surface position away from the minimum inner diameter portion B and the maximum outer diameter portion A of the ring body 7b.

  The molding device for the seal ring 7 has a pair of upper and lower molds 1 and 2 as in the conventional case, and is placed in a cavity CV formed of opposed annular grooves 5 and 6 formed in the molds 1 and 2. A rubber or elastic synthetic resin material is loaded and compression molded.

  1 and 2 show a seal ring molding apparatus according to an embodiment of the present invention. However, the molding apparatus of FIGS. 1 and 2 is arranged upside down and the structure of both is substantially the same. Therefore, details will be described with reference to FIG.

  That is, these are composed of a pair of upper and lower molds 1 and 2, and semicircular annular grooves 5 and 6 are formed on the split surfaces 3 and 4 of the molds 1 and 2, respectively. A molding device for a seal ring which forms a cavity CV oppositely, inserts a molding material into the cavity CV, and cures the molding material by heating and pressing while matching the molten state and timing of the molding material, The split surfaces 3 and 4 are formed along a position away from the diameter line X of the cavity CV. In other words, the split surfaces 3 and 4 are formed at positions away from the minimum diameter portion B and the maximum outer diameter portion A of the cavity CV.

  The molding apparatus in FIG. 1 uses an upper mold 1 as a male side and a lower mold 2 as a female side, and includes a conical male inclined surface and a central horizontal plane on the lower surface of the upper mold 1. It has a split surface 3, and has a split surface 4 consisting of a conical female inclined surface facing the split surface 3 and a central horizontal surface on the upper surface of the lower mold 2, A cavity CV composed of annular grooves 5 and 6 facing each other is formed.

  For this reason, the extending direction of the split surfaces 3 and 4 is a direction that crosses while being inclined with respect to the diameter line X.

  The sealing ring molding method using the molds 1 and 2 is basically the same as that described in the background art of the related art, on each of the split surfaces 3 and 4 of the pair of upper and lower molds 1 and 2, respectively. A molding material is inserted into an annular cavity CV formed with the formed semicircular annular grooves 5 and 6 facing each other, and the molding material is cured by heating and pressing in accordance with the molten state and timing of the molding material. It is.

  In the present invention, the split surfaces 3 and 4 are formed along a position away from the diameter line X in the diametrical direction of the cavity CV, and when the molds 1 and 2 are pressed, A streak-like burr generated along the circumferential direction between the split surfaces 3 and 4 is generated at a peripheral surface position away from the diameter line X of the seal ring seal ring main body 7b.

  That is, the burrs are generated at both side portions a and b near the cavity CV along the split surfaces 3 and 4, but the portions a and b are separated from the diameter line X. , B is inserted into the annular groove 12 of the piston 10 shown in FIG. Without increasing the sliding resistance of the piston 10 or preventing fluid and gas from leaking due to the gap caused by the deformation of the burr.

  Similarly, an O-ring seal ring 7 is provided on the inner periphery of the rod guide of the hydraulic / pneumatic cylinder, and even if the piston rod is movably inserted into this rod guide, The burr that does not slide on the outer periphery of the piston rod does not cause a problem that increases the sliding resistance of the piston rod.

  The above-described molding apparatus shown in FIG. 1 and FIG. 2 is, for example, as shown in FIG. Is preferably formed.

  FIG. 4 relates to a molding apparatus according to another embodiment of the present invention, which is composed of a pair of upper and lower molds 1 and 2, and split surfaces 3 and 4 of each mold 1.2 are inclined surfaces 3 a and 4, respectively. 4a and horizontal planes 3b and 4b. The inclined surfaces 3a and 4a are eccentric from the diameter line X of the seal ring body 7 as described above, but the horizontal planes 3b and 4b are the same extension line as the diameter line X. Is formed.

  In this case, the burr generated in the part a does not give sliding resistance to the mating member that is in sliding contact as described above. Moreover, since the burr | flash generate | occur | produced in the site | part b is located on the diameter line of the seal ring seal ring main body 7b similarly to the past, it is not used for embodiment which inserts a sliding member in the inner periphery of this seal ring main body 7b. There are many cases.

  FIG. 5 relates to another embodiment of the present invention, which utilizes a split surface formed opposite to the split surface of the embodiment of FIG.

  That is, the split surface 3 of the upper mold 1 is composed of a central female inclined surface 3a and a horizontal surface 3b along the diameter line X. The split surface 4 of the lower mold 2 has a diameter equal to that of the central male inclined surface 4a. And a horizontal plane 4b along the line X.

  In this embodiment, the inclined surfaces 3a and 4a are eccentric from the diameter line X, and the burr generated at the part b is deviated from the diameter line in the diameter direction.

  For this reason, the molded seal ring 7 is provided on the inner periphery of the rod guide of the oil / pneumatic cylinder, and the inner periphery of this rod guide is used as a part b when used as a shaft seal mechanism in which the piston rod is slidably inserted. The generated burr does not slide on the piston rod and does not adversely affect the operation of the piston rod.

  FIG. 6 relates to a molding device for a seal ring according to another embodiment of the present invention, which includes a pair of upper and lower molds 1, 2 and horizontal split surfaces 3, 4 formed on the molds 1, 2. The cavity CV is formed by annular grooves 5 and 6 formed in the middle of each of the split surfaces 3 and 4.

  In this respect, it is the same as the prior art shown in FIG. 9, but in the present invention, the positions of the split surfaces 3 and 4 are provided at positions that are eccentrically spaced upward from the diameter line X of the cavity CV. For this reason, the burrs generated in the parts a and b are also deviated from the diameter line X, and the burrs of the obtained seal ring 7 have the same adverse effects on the mating members such as the cylinder, piston, piston rod, etc. that are in sliding contact. Not give.

  FIG. 7 relates to another embodiment of the present invention, in which the molds 1 and 2 shown in FIG. 1 or FIG. 2 are integrally connected in the lateral direction.

  In this case, since many cavities CV exist, many seal rings 7 can be shape | molded at once.

  However, even in this case, since the dies 1 and 2 are long in the horizontal direction, they cannot be precisely aligned, and when pressed, the respective parts cannot be pressed uniformly and may be displaced in the vertical direction.

  In this case, since the upper and lower cavities CV are not exactly opposed to each other, there is a possibility that a defective seal ring 7 is formed due to the shift of the mold as shown on the left and right in FIG.

  In view of this, another embodiment of a seal ring molding apparatus for preventing the molds 1 and 2 from shifting has been developed as shown in FIG.

  This is because a pair of upper and lower molds 1 and 2 are arranged in a plurality of rows in the horizontal direction, and the molds 1 and 2 are held by separate molds 16 and 17, respectively. By adjusting the position of the other mold 1 while being fixed, positional deviation between the pair of upper and lower molds 1 and 2 is prevented.

  That is, a number of grooves 14 are formed in the lower mold 17, and the lower mold 2 is fitted and positioned in each of the grooves 14. The upper die 16 includes a presser frame 15 and bolts 13. The presser frames 15 are uniformly abutted against the upper surface of each upper die 1, and the presser frame 15 and the upper die 1 are connected with bolts 13. The upper molds 1 are joined uniformly and integrally, and the upper molds 1 are pressed together in a uniform manner to form a large number of seal rings 7 with the lower molds 2 at a time.

  The upper mold 1 is adjusted in position with respect to the mold 16 and fixed with bolts 13 so that the relative positions of the upper mold 1 and the lower mold 2 coincide. In this case, not only the upper mold 1 but also the lower mold 2 side may be assembled to the lower mold frame 17 so that the position can be adjusted.

  In this embodiment, the upper and lower molds 1 and 2 are held by the molds 16 and 17 and are interlocked uniformly, so that the shift between the molds 1 and 2 is prevented and the occurrence of a defective seal ring can be prevented.

It is a vertical front view of the seal ring shaping | molding apparatus concerning one embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. It is a vertical front view of the seal ring shaping | molding apparatus concerning other embodiment of this invention. (A), (B), and (C) are longitudinal sectional front views of a conventional sealing ring molding apparatus. (A), (B), and (C) are a plan view, a longitudinal sectional view, and a partially enlarged sectional view of a conventional seal ring. It is a partially expanded sectional view of the hydraulic cylinder of the state which attached the conventional seal ring to the piston.

Explanation of symbols

1, 2 Mold 3, 4 Split surface 5, 6 Annular groove 7 Seal ring 7a Burr 7b Seal ring body A Maximum outer diameter B Minimum outer diameter X Diameter wire CV Cavity

Claims (6)

In the seal ring where streak-like burrs remain along the circumferential direction on the outer periphery, inner periphery, or both outer periphery and inner periphery of the seal ring body during compression molding, the minimum inner diameter portion and the maximum outer diameter portion of the seal ring body Seal ring with burr remaining on the peripheral surface away from An annular cavity is formed by facing the semicircular annular grooves formed on each split surface of the pair of upper and lower molds, a molding material is inserted into the cavity, and the molten state of the molding material is matched with the timing In a sealing ring molding method in which the molding material is cured by heating and pressing, the split surfaces are formed at positions apart from the minimum inner diameter portion and the maximum outer diameter portion of the cavity, and the molds are pressurized. Forming a seal-like burr generated along the circumferential direction between the split surfaces at a peripheral surface position away from the minimum inner diameter portion and the maximum outer diameter portion of the seal ring body. Method It consists of a pair of upper and lower molds. Opposite semicircular annular grooves formed on each split surface of each mold are formed to form an annular cavity, and a molding material is inserted into the cavity to melt the molding material. In a sealing ring molding apparatus that cures the molding material by applying heat and pressure while matching the state and timing, the split surface is formed at positions separated from the minimum inner diameter portion and the maximum outer diameter portion of the cavity. Seal ring molding equipment 4. The sealing ring molding apparatus according to claim 3, wherein, of the pair of upper and lower molds, the split surface of one mold is a male inclined surface, and the split surface of the other mold is a female inclined surface. 4. A sealing ring molding apparatus according to claim 3, wherein each of the split surfaces in the pair of upper and lower molds is a horizontal plane formed along a position away from the diameter line connecting the minimum inner diameter portion and the maximum outer diameter portion of the cavity. A plurality of pairs of upper and lower molds are arranged in the horizontal direction, and each mold is held by a separate mold, and the position of the other mold is adjusted while at least one mold is fixed. 6. A sealing ring molding apparatus according to claim 3, wherein the positional deviation between the pair of upper and lower molds is prevented.

Images