JP2008008493A - Manufacturing method of sealing ring for separate-type mechanical seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing easily and cheaply a sealing ring for separate-type mechanical seals which is a separate-type ring made from a brittle material. <P>SOLUTION: To an inside and an outside peripheral surfaces 1a, 1c of a brittle material ring 1 made from carbon, ceramics or cemented carbide, in two places on one diameter line 2, after forming minute notch grooves 3a and 3b prolonged in an axial direction, to the ring concerned 1, external forces F, F are given so that a diameter of the ring is enlarged to a direction perpendicular to the diameter line 2 making a crack advance from a notch groove 3a by the side of an inner circumference surface to a notch groove 3b of outer peripheral face side, by this the ring concerned 1 is made to be divided into two so as to make the divided surfaces 10d, 10e become irregular and finely rugged faces, the external forces are given through a pair of pressing tools 5 and 5 opposed on both sides of the diameter line 2, and carries out connection to the ring inner circumferential surface 1a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a split ring for a mechanical seal by dividing a brittle ring made of carbon, ceramics or cemented carbide in the circumferential direction.

    Conventionally, the sealing ring provided on the seal case side and the sealing ring provided on the rotating shaft side are relatively rotationally slidably contacted with each other at the sealing end surface which is the opposite end surface thereof, so that the inner and outer peripheral sides of the relative rotating slidable contact portion In order to facilitate maintenance work such as replacement and repair of the seal ring due to wear damage on the sealing end surface, etc. It has been proposed to divide the sealing ring in the radial direction (see, for example, Patent Document 1).

  Thus, such a split seal ring is generally obtained by individually manufacturing semicircular seal ring components 21, 22 as shown in FIGS. It is normal. That is, as shown in FIG. 8, arc-shaped materials 21a and 22a having a predetermined amount δ of polishing allowances 21b and 22b at both ends are manufactured, and the polishing allowances 21b and 22b of these arc-shaped materials 21a and 22a are polished ( By removing (wrapping, polishing, etc.), the sealing ring components 21, 22 are produced. As shown in FIG. 7, the polishing allowances 21 b and 22 b are polished so that the desired sealing rings 20 are constructed by bringing the polishing surfaces 21 c and 22 c of the sealing ring components 21 and 22 into contact with each other.

JP 2001-065706 A

  However, since such a split seal ring 20 is obtained by individually manufacturing each of the seal ring components 21 and 22, a high level of skill is required for polishing the arcuate materials 21a and 22a. In other words, when the accuracy of the polishing surfaces 21c and 22c is low, the sealing ring components 21 and 22 cannot form an appropriate annular shape and cannot make contact with each other, and the sealing ring 20 becomes a defective product. Therefore, when the worker is not a highly skilled worker, the defective product generation rate is high and the production efficiency is also poor. Further, expensive brittle materials such as carbon, ceramics, cemented carbide and the like are used as the constituent material of the seal ring for the mechanical seal, but the arc-shaped materials 21a and 22a are polished to obtain the seal ring constituent parts 21 and 22. For this reason, the yield of the material is bad and the manufacturing cost is high. Furthermore, since the abutting surfaces 21c and 22c of the sealing ring component parts 21 and 22 are smooth flat surfaces (polished surfaces), when the sealing ring 20 is incorporated in a mechanical seal, the abutting surfaces 21c and 22c are caused by pressure fluctuations or the like. It is difficult to exhibit a good sealing function such as causing a gap between the abutting surfaces 21c and 22c.

  An object of the present invention is to provide a method capable of easily and inexpensively manufacturing a split ring made of a brittle material, which is a sealing ring for a split mechanical seal, without causing the above-described problems. is there.

In order to achieve the above-mentioned object, the present invention provides one brittle ring made of carbon, ceramics (SiC, Al ₂ O ₃ etc.) or cemented carbide (WC, TiC etc.) on the inner and outer peripheral surfaces. At two locations on the diameter line, a minute notch groove extending in the axial direction is formed over the entire width of the inner and outer peripheral surfaces, and an external force is applied to the ring to expand the diameter in a direction perpendicular to the diameter line. Then, by causing a crack to progress along the diameter line from the notch groove on the inner peripheral surface side to the notch groove on the outer peripheral surface side, the split surface of the ring becomes an irregular and fine uneven surface. A method of manufacturing a split ring for a mechanical seal that is divided into two in the circumferential direction, wherein the application of the external force to the brittle ring is opposed across the diameter line without physical impact. And abut against the inner circumferential surface of the ring The brittle material ring is placed on a placement surface that is a horizontal surface, and the opposing surfaces (5b, 5b) are formed between the opposing surfaces of the two pressing jigs. ), And a camshaft (6) having a constricted shape, which is loaded between the two, is pressed down to gradually expand in a direction perpendicular to the diameter line (2). We propose a method for manufacturing a sealing ring. In such a method, it is preferable that the brittle material ring is placed on the placement surface in a state where the ring surface which is one side end surface functioning as a sealing end surface is facing up. Further, it is preferable that the mounting surface is formed as a smooth surface with low friction by coating a low friction material such as polytetrafluoroethylene (PTFE).

  According to the present invention, it is possible to easily and inexpensively manufacture a sealing ring for a split type mechanical seal without requiring a high degree of skill. In addition, since the dividing surface is an irregular and fine uneven surface, it is possible to appropriately secure and maintain the abutting form of the dividing ring, and to effectively exhibit the function of the dividing ring as a sealing ring. .

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a cross-sectional plan view showing a method according to an embodiment of the present invention (the cross section is taken along the line II in FIG. 2), (A) shows the division start state, and (B) The figure shows the division completion state. 2 is a longitudinal front view taken along the line II-II in FIG. 1. FIG. 2A shows a split start state, and FIG. 2B shows a different form of the split ring from FIG. FIG. 3C shows a division start state when the ring is placed and held on the back side of the ring, and FIG. FIG. 3 is a plan view showing the main part (ring to be divided) of FIG. 1A taken out, FIG. 4 is a vertical side view taken along the line IV-IV of FIG. 3, and FIG. Fig. 6 is a plan view showing a brittle material ring (sealing ring for split type mechanical seal), and Fig. 6 is an enlarged detailed view showing a main part of Fig. 5.

  This embodiment relates to an example in which the brittle ring 1 shown in FIG. 3 is divided by the method of the present invention to produce the split type mechanical seal sealing ring 10 shown in FIGS.

In carrying out the method of the present invention, first, a completed form of a desired sealing ring 10 (half-circular sealing ring components 10a and 10b described later are brought into contact with an appropriate annular shape as shown in FIG. The ring 1 made of a brittle material (hereinafter referred to as “divided ring”) 1 having a shape matching the above-described shape is manufactured. As shown in FIGS. 3 and 4, the inner and outer peripheral surfaces 1 a and 1 b of the ring 1 to be split have the full width of the inner and outer peripheral surfaces 1 a and 1 b (full width in the axial direction) at two locations on one diameter line 2. Notch grooves (notches) 3a and 3b extending in the axial direction are formed. Each of the cutout grooves 3a and 3b is a V-shaped groove (FIG. 3A) or a U-shaped groove (FIG. 3B) having a small and constant groove width and groove depth. Further, the ring surface 1c, which is one side end face of the ring 1 to be split, is polished to a smooth surface (mirror surface) orthogonal to the axis, and the inner and outer peripheral edge portions where the notched grooves 3a and 3b are formed on the ring surface 1c. The annular portion having a predetermined width (seal surface width) W that functions as a seal functions as a sealing end surface 10c that is in sliding contact with the mating sealing ring when the sealing ring 10 is incorporated into a mechanical seal. In addition, as a constituent material of the ring 1 to be divided, a brittle material is used according to conditions such as the purpose and function of the mechanical seal in which the seal ring 10 is incorporated and the material of the mating seal ring. Specifically, carbon, ceramics such as SiC and Al ₂ O ₃ or cemented carbide such as WC and TiC are used.

  Then, as shown in FIGS. 1 and 2, by applying external forces F and F that expand the ring 1 in the direction perpendicular to the diameter line 2 to the split ring 1 configured as described above, the ring 1 Is divided into semicircular seal ring components 10a and 10b to obtain a desired split seal ring 10.

  That is, first, as shown in FIGS. 1 (A), 2 (A), and 2 (B), the split ring 1 is placed and held on a horizontal placing table 4 and a pair of pressing jigs 5 on the ring inner peripheral surface 1a. , 5 are brought into contact with each other. By the way, the mounting form of the split ring 1 on the mounting table 4 is such that the ring surface 1c which is one side end face (end face on the side where the sealing end face 10c is formed) faces downward (FIG. 2A). Even if it is the form (form shown in the figure (B)) which turned down the ring back surface 1d which is the other side end surface (end surface in which the sealing end surface 10c is not formed). Although the latter is preferred. In any case (especially in the case of the former), the surface to be slid (ring surface 1c or ring back surface 1d) of the ring 1 and the upper surface of the mounting table 4 at the time of a split action described later. In order not to damage the sliding contact surface due to the relative sliding contact with the mounting surface 4a, the mounting surface 4a is coated with a low friction material such as polytetrafluoroethylene (PTFE) and smoothed with low friction. It is preferable to configure in a horizontal plane. Both pressing jigs 5 and 5 are loaded in the split ring 1 so as to face each other across the diameter line 2 where the notched grooves 3a and 3b are located, and are symmetrical with respect to the diameter line 2. The arc shape. As shown in FIGS. 1 and 2, each pressing jig 5 is configured so that the outer peripheral surface 5a is an arcuate surface (having the same diameter as the ring inner peripheral surface 1a) that is in close contact with the ring inner peripheral surface 1a. 5b is formed as an arc-shaped tapered surface whose radius of curvature gradually decreases in the downward direction, the lower end surface is brought into contact with the mounting surface 4a, and the outer peripheral surface 5a extends to the ring inner peripheral surface 1a over its entire vertical width. In a state where they are in contact with each other.

  Next, as shown in FIGS. 1 (A) and 2 (A) (B), the lower end portion of the cam member 6 having a narrowed shape is loaded between the opposing surfaces 5b, 5b of the pressing jigs 5, 5. In addition, the cam body 6 is gradually pushed down by applying a downward pressing force P to the cam body 6 by appropriate pressing means (press machine or the like). The pressing jig is configured so that the outer peripheral surface 6a of the cam body 6 gradually spreads between the opposing surfaces 5b and 5b of the pressing jigs 5 and 5 in a direction perpendicular to the diameter line as the cam body 6 is lowered. The cam surface is configured as a constricted cam surface that can function with respect to the tapered surfaces 5b and 5b.

  Thus, when the cam body 6 is pressed downward, external forces F and F that cause the ring 1 to be split to expand in the direction perpendicular to the diameter line 2 via the pressing jigs 5 and 5. Is granted. Therefore, as the cam body 6 is lowered, a crack is generated in the split ring 1 starting from the notch groove 3a on the inner peripheral surface side. After the crack, the crack is cut from the notch groove 3a to the notch groove on the outer peripheral surface side. Proceeding to 3b, as shown in FIG. 1 (B) and FIG. 2 (C), the ring 1 is divided into two semicircular sealing ring components 10a and 10b.

  At this time, since the external forces F and F act in a direction perpendicular to the diameter line 2 passing through the cutout grooves 3a and 3b, the cracks from the cutout groove 3a on the inner peripheral surface side to the cutout groove 3b on the outer peripheral surface side. It will surely proceed. Therefore, the split ring 1 does not cause cracks or local defects other than the portions where the notched grooves 3a and 3b are formed, and the split ring 1 is properly positioned on the planned diameter line 2. Can be divided into Therefore, the ratio of occurrence of poorly divided products is extremely low, and the brittle material ring 1 can be divided very economically. Further, since the external forces F and F are applied to the split ring 1 through the arc-shaped pressing jigs 5 and 5 that are brought into contact with the inner peripheral surface 1a of the ring without physical impact, the ring When the external force F, F is directly applied to the inner peripheral surface 1a at a pinpoint (when the external force F, F is applied only to the inner peripheral surface of the ring on the diameter line perpendicular to the diameter line 2) The ring 1 is not broken or cracked at portions other than the portions where the cutout grooves 3a and 3b are formed, and the above-described proper division is performed reliably.

  Further, since the split ring 1 is placed on the low friction smooth horizontal surface (mounting surface) 4a, the ring 1 is horizontally divided by the external forces F and F (shearing action). Friction resistance between the mounting surface 4a and the ring surface 1c (see FIG. 2 (A)) or the ring back surface 1d (see FIG. 2 (B)) in contact with the mounting surface 4a (and the mounting surface 4a and the jigs 5 and 5) There is no fear of being hindered by the frictional resistance between the lower surface and the ring is smoothly and satisfactorily divided. In this case, when the ring 1 is placed on the placement surface 4a with the ring surface 1c on which the sealed end face 10c is formed facing up, as shown in FIG. Of course, as shown in FIG. 5A, when the ring surface 1c is placed on the placement surface 4a with the ring surface 1c facing down, the placement surface 4a is a smooth horizontal surface having low friction as described above. Therefore, there is no possibility that the sealed end face 10c is damaged by the relative sliding movement of the both faces 1c and 4a at the time of division.

  By the way, the ring 1 to be divided is heated and then rapidly cooled to divide the ring 1 by a thermal shock, or the ring 1 to be divided (sheared) by directly applying a physical impact thereto. However, according to the former method, even if a crack occurs starting from the notch groove 3a on the inner peripheral surface side, it is unclear whether the end point of the crack becomes the notch groove 3b on the outer peripheral surface side. In addition, accurate ring division cannot be performed, and unexpected distortion may occur in the divided portions 10a and 10b due to heating and rapid cooling. Further, according to the latter method, there is a possibility that a crack may occur in a portion where the notch grooves 3a and 3b are not formed, ring defects are likely to occur, and the defective product occurrence rate becomes extremely high. However, according to the dividing method described above, such a problem does not occur, and the ring 1 to be divided can be reliably divided on the line connecting the cutout grooves 3a and 3b.

  The abutting surfaces of the sealing ring components 10a and 10b obtained by dividing the ring 1 to be divided into two as described above, that is, the dividing surfaces 10d and 10e of the sealing ring 10 are fine and as shown in FIG. It becomes an irregular uneven surface, and the uneven engagement is performed in a state in which relative sliding does not occur in the direction parallel to the divided surfaces 10d and 10e (the axial direction and the radial direction of the sealing ring 10). Therefore, when the seal ring 10 is incorporated into a mechanical seal, the relative engagement (displacement) in the axial direction and the radial direction of the seal ring components 10a and 10b does not occur due to the concave and convex engagement of the dividing surfaces 10d and 10e. Can be held in an appropriate annular body, and a good sealing function is exhibited without causing leakage from the divided surfaces 10d and 10e. Moreover, positioning at the time of abutting of the sealing ring components 10a and 10b, that is, proper abutting of the divided surfaces 10d and 10e can be easily performed, and the sealing ring 10 can be incorporated into the mechanical seal appropriately and easily. Can do.

  Further, unlike the case where the sealing ring components 21 and 22 are manufactured separately as described at the beginning, the split ring 1 manufactured in the same shape as the completed form of the sealing ring 10 is divided into two parts, so that the material yield is increased. The split seal ring 10 can be easily and inexpensively manufactured without requiring a high degree of skill.

  It should be noted that the present invention is not limited to the above-described embodiment, and can be appropriately improved and changed without departing from the basic principle of the present invention. For example, the shape of the cutout grooves 3a and 3b is not limited to the V-shaped groove shown in FIG. 3A or the U-shaped groove shown in FIG. What is necessary is just to be able to function as a guide line between both points.

FIG. 2 is a cross-sectional plan view showing the embodiment of the method according to the present invention (the cross section is taken along the line II in FIG. 2), (A) shows the division start state, and (B) shows division completion. Indicates the state. It is a vertical front view along the II-II line of FIG. 1, (A) The figure has shown the division | segmentation start state, (B) FIG. The form of division start in the case of being placed and held is shown in FIG. 5C, and FIG. It is a top view which takes out and shows the principal part (divided ring) of FIG. 1 (A). It is a vertical side view along the IV-IV line of FIG. It is a top view which shows the ring made from the brittle material (sealing ring for mechanical seals) divided | segmented. FIG. 6 is an enlarged detailed view showing a main part of FIG. 5. It is a top view which shows the sealing ring for mechanical seals manufactured by the conventional method. It is a top view which shows the constituent material of the sealing ring.

Explanation of symbols

1 Ring to be split (ring made of brittle material)
DESCRIPTION OF SYMBOLS 1a Inner peripheral surface 1b Outer peripheral surface 2 Diameter line 3a Notch groove on the inner peripheral surface side 3b Notched groove on the outer peripheral surface side 4 Mounting table 4a Mounting surface 5 Pressing jig 5a Outer peripheral surface of the pressing jig 5b Inner circumference of the pressing jig Surface (opposite surface)
6 Cam body 6a Cam surface 10 Sealing ring 10a Sealing ring component 10b Sealing ring component 10c Sealing end face 10d Abutting surface (divided surface)
10e Contact surface (divided surface)

Claims (3)

On the inner and outer peripheral surfaces (1a, 1b) of the brittle material ring (1) made of carbon, ceramics or cemented carbide, the inner and outer peripheral surfaces (1a, 1b) at two locations on one diameter line (2). ) Is formed on the ring (1) in the direction perpendicular to the diameter line (2) (F). , F) and a crack is advanced along the diameter line (2) from the notch groove (3a) on the inner peripheral surface side to the notch groove (3b) on the outer peripheral surface side, whereby the ring (1 ) Is divided into two in the circumferential direction so that the divided surfaces (10d, 10e) are irregular and fine irregular surfaces,
The application of the external force (F, F) to the brittle material ring (1) is opposed to the diameter line (2) and is in contact with the inner peripheral surface (1a) of the ring without being caused by a physical impact. It is performed via a pair of pressing jigs (5, 5), and the brittle material ring (1) is placed on the mounting surface (4a) which is a horizontal surface, and both pressing jigs ( 5, 5) by pressing and lowering the constricted cam body (6) loaded between the opposing surfaces (5 b, 5 b) between the opposing surfaces (5 b, 5 b), thereby the diameter line (2 A method of manufacturing a sealing ring for a split type mechanical seal, characterized in that the seal ring is gradually expanded in a direction perpendicular to ().   The brittle material ring (1) is placed on the placement surface (4a) with the ring surface (1c) serving as one end face functioning as the sealing end face (10c) facing up. A method for manufacturing a sealing ring for a split mechanical seal according to claim 1.   The method of manufacturing a split ring for a mechanical seal according to claim 1 or 2, wherein the mounting surface (4a) is a smooth surface with low friction.

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