JP2006071108A - End face seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide seal structure for preventing the occurrence of a setting phenomenon to a seal member at an early stage, with which stable seal performance can be secured during a long period, in an end face seal to seal the end face parts of pressure instruments, such as an accumulator, or other instruments. <P>SOLUTION: The end face seal is an end face seal to seal a gap between an end face part 3b and an actuating member 5 moving toward the end face part 3b and has a seal member 2 mounted on the end face part 3b. The seal member 22 has a seal lip 22b making close contact with the actuating member as a result of it being pushed by a sealing fluid pressure when the actuating member 5 is stopped with it brought into close contact with the end face part 3b or stopped by a stopper. The tip end part of the seal lip 22b is provided with a plurality of seal protrusions 22e and 22f making close contact with respective actuating members 5. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an end face seal which is a kind of sealing device.

  Conventionally, an accumulator 51 shown in FIG. 6 is known as a pressure device having an end face seal, and is configured as follows.

  That is, first, cover members 54 and 55 are welded and fixed to both ends of the cylindrical shell 53, and a housing 52 is provided. An operation member 56 including a bellows 57 and an end member 58 is provided inside the housing 52. Contained. One end of the bellows 57 is fixed to one lid member 54 and the other end is fixed to an end member 58. Therefore, the bellows 57 and end member 58 allow the inside of the housing 52 to be bellows 57 and end member 58. Are divided into an inner gas chamber 59 and an outer pressure chamber 60.

  One lid member 54 on the left side of the figure is provided with an inlet 61 for injecting gas into the gas chamber 59, and a plug member 62 for closing the inlet 61 is provided at the inlet 61. It is attached. Therefore, the plug member 62 is removed and a predetermined pressure gas is injected from the injection port 61 into the gas chamber 59. After the injection, the injection port 61 is closed with the plug member 62 so that the predetermined pressure gas is sealed in the gas chamber 59. To do.

  Further, the other lid member 55 on the right side in the figure is provided with a mounting portion 63 having a screw portion 64 for connecting the accumulator 51 to a pressure pipe such as a hydraulic pipe (not shown). A pressure introduction port 65 for introducing the pressure into the pressure chamber 60 is provided. Therefore, the accumulator 51 is connected to the pressure pipe at the attachment portion 63, and the pressure in the pressure pipe is introduced into the pressure chamber 60 from the pressure introduction port 65.

  The accumulator 51 having the above-described configuration serves to absorb, for example, pressure pulsation generated in the pressure pipe by balancing the sealed gas pressure in the gas chamber 59 and the pressure in the pressure chamber 60. If the pressure in the pressure chamber 60, that is, the pressure in the pipe is extremely lowered, the bellows 57 may swell due to the pressure difference between the inside and the outside and buckle and break.

  Therefore, as a countermeasure, the end face seal 66 is attached to the end face of the end member 58 by the baking means in the accumulator 51, and the pressure in the pressure chamber 60 is reduced to a predetermined value or less by the sealing action of the end face seal 66. It is supposed not to. That is, when the pressure in the pressure chamber 60 decreases during operation, the bellows 57 extends long, and the end surface seal 66 attached to the end surface of the end member 58 comes into close contact with the end surface portion 55a of the other lid member 55. The pressure chamber 60 and the pressure introduction port 65 are blocked by the sealing action of the end face seal 66 by close contact. Therefore, after this shut-off, even if the pressure in the pressure pipe further decreases, the pressure in the pressure chamber 60 does not decrease, so the sealed gas pressure in the gas chamber 59 and the pressure in the pressure chamber 60 are kept in equilibrium. Therefore, the bellows 57 is prevented from expanding.

  However, in the conventional accumulator 51, the end face seal 66 is attached to the end face of the end member 58 as described above, and the end face seal 66 faces the end face portion 55a of the lid member 55 and the end face portion 55a. Since it is set so as to be sealed by being sandwiched between the end member 58 that moves based on a predetermined pressure difference, the end surface seal 66 is provided between the end surface portion 55 a and the end member 58. Since this is repeated every time the bellows 57 expands and contracts due to pressure fluctuations, the end face seal 66 undergoes a sag phenomenon relatively early, thereby causing the end face seal. There is an inconvenience that the sealing performance of 66 decreases rapidly.

  In view of the above points, the present invention can prevent a sag phenomenon from occurring at an early stage in a seal member in an end face seal that seals an end face part of a pressure device such as an accumulator or other devices, and is thus stable. It is an object of the present invention to provide a seal structure that can ensure the sealing performance over a long period of time.

  In order to achieve the above object, an end face seal according to claim 1 of the present invention is an end face seal that seals between an end face portion and an operating member that moves toward the end face portion, and is attached to the end face portion. A seal member, and the seal member has a seal lip that is pressed by a sealing fluid pressure to come into close contact with the actuating member when the actuating member abuts against the end surface portion and stops or stops by a stopper; A plurality of seal protrusions that are in close contact with the operating member are provided at the tip of the seal lip.

  An end face seal according to claim 2 of the present invention is the end face seal according to claim 1, wherein the seal member has a seal lip and an outer peripheral side seal lip in close contact with the inner surface of the seal mounting portion. .

  In the end face seal according to claim 1 of the present invention having the above-described configuration, the seal member is mounted not on the moving side actuating member but on the stationary side end face, and the actuating member moving toward the end face is provided. In a state where the end face part comes into contact with the end face part and is stopped by a stopper provided separately for the end face part, the seal lip of the seal member of the end face seal is pressed by the sealing fluid pressure to come into close contact with the operating member, thereby sealing the end face part. The effect is demonstrated. Therefore, sealing is not performed in a state where the sealing member is strongly sandwiched between the rigid members, but is performed in a state where the sealing lip of the sealing member is in close contact with the moving member that has already stopped with a predetermined contact pressure. Thus, it is possible to prevent the occurrence of a premature sag phenomenon or the like in the seal member provided with the seal lip. In addition to this, since a plurality of seal protrusions that are in close contact with the operating members are provided at the front end of the seal lip, even if troubles such as the entry of foreign matter occur in the sealing action of one seal protrusion, The sealing action can be maintained by other sealing protrusions.

  Further, in the end face seal according to claim 2 of the present invention having the above-described configuration, since the seal member is provided with the outer peripheral side seal lip in close contact with the inner surface of the seal mounting portion together with the seal lip, the end face seal Also, it is possible to exhibit a good sealing action between the end face portions on which these are mounted.

  When the invention according to claims 1 and 2 of the present application is applied to an accumulator that is a pressure device as described above, the end face seal is attached to the end face portion of the accumulator housing corresponding to the end face portion of the present invention. Installing. In this case, regarding the material of the seal member or seal lip, EPDM or the like is used when the pressure element (sealing fluid or target fluid) introduced into the pressure chamber of the accumulator is a brake fluid or the like. It is preferable to use rubber such as NBR. The hardness of the seal member or the seal lip is preferably set to a relatively high value in consideration of prevention of the seal lip from protruding against a high pressure.

  The present invention has the following effects.

  That is, in the end face seal according to claim 1 of the present invention, there is provided an end face seal for sealing between the end face portion and the actuating member moving toward the end face portion, and the seal member attached to the end face portion is provided. The seal member is attached to the stationary end face portion instead of the actuating member side that moves during operation, and the actuating member moving toward the end face portion is in contact with the end face portion and stopped, or stopped by a stopper. In this state, the seal lip of the seal member of the end face seal is pressed by the sealing fluid pressure to come into close contact with the end member, so that the seal member is strongly sandwiched between the rigid members. Instead, the sealing is performed in a state where the sealing lip of the sealing member is in close contact with the end member that has already stopped with a predetermined contact pressure. Accordingly, since the seal member having the seal lip is not strongly sandwiched between the rigid members in a compressed state, it is possible to prevent the seal member from prematurely sagging, thereby stabilizing the seal member. The sealed performance can be secured over a long period of time. In addition to this, since a plurality of seal protrusions that are in close contact with the operating members are provided at the front end of the seal lip, even if troubles such as the entry of foreign matter occur in the sealing action of one seal protrusion, The sealing action can be maintained by other sealing protrusions. Therefore, the part sealing performance can be further improved.

  In the end face seal according to claim 2 of the present invention, since the seal member is provided with the seal lip and the outer peripheral side seal lip in close contact with the inner surface of the seal mounting portion, the end face seal and the end seal are mounted. It is possible to exert a good sealing action between the end surfaces. Therefore, also from this point, the sealing performance can be improved.

  Next, embodiments of the present invention will be described with reference to the drawings.

First embodiment ...
FIG. 1 shows a cross section of a metal bellows type accumulator 1 equipped with an end face seal 21 according to a first embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view of the end face seal 21.

  In the accumulator 1 of FIG. 1, first, a cover member (also referred to as an end cover or a gas end cover) 4 is welded and fixed to an open end portion of a bottomed cylindrical shell 3, and a housing 2 is provided. Is accommodated with an operating member 5 including a bellows 6 and an end member (also referred to as a bellows cap) 7. One end of the bellows 6 is fixed to the lid member 4 and the other end is fixed to the end member 7, so that the inside of the housing 2 is inside the bellows 6 and the end member 7 by the bellows 6 and the end member 7. Gas chamber 8 and an outer pressure chamber (also referred to as a fluid chamber) 9. The bellows 7 is a metal bellows made of an electrodeposition bellows, a molded bellows, a welded bellows, or the like. Depending on the specifications and applications of the accumulator 1, a bellows of other materials can be used. The end member 7 may be integrally formed with the bellows 6.

  An upper inlet 10 for injecting gas into the gas chamber 8 is provided in the upper lid member 4 in the figure, and a packing 12 such as an O-ring for closing the inlet 10 is provided in the inlet 10. A provided screw-type plug member (also referred to as a gas plug) 11 is attached. Therefore, the plug member 11 is removed and a gas having a predetermined pressure is injected from the inlet 10 into the gas chamber 8. After the injection, the inlet 10 is closed with the plug member 11, so that the gas having a predetermined pressure is supplied to the gas chamber 8. Encapsulate. Nitrogen gas, inert gas, etc. are suitable as the type of gas to be sealed.

  Further, an attachment portion 13 having a screw portion 14 for connecting the accumulator 1 to a pressure pipe such as a hydraulic pipe (not shown) is provided on the end wall 3a of the shell 3 on the upper and lower sides of the figure. A pressure introduction port (also referred to as a fluid flow path) 15 for introducing the internal pressure into the pressure chamber 9 is provided. Therefore, the accumulator 1 is connected to the pressure pipe at the attachment portion 13, and the pressure in the pressure pipe is introduced into the pressure chamber 9 from the pressure inlet 15.

  An annular sliding member (also referred to as a vibration damping ring) 16 is mounted on the outer peripheral side of the other end of the bellows 6 fixed to the end member 7 or on the outer peripheral side of the end member 7. Thus, when the end member 7 moves, the sliding member 16 slides with respect to the inner peripheral surface of the shell 3 with its outer peripheral portion. Therefore, by the sliding guidance of the sliding member 16, the end member 7 moves in parallel with the inner peripheral surface of the shell 3 and the bellows 6 expands and contracts in parallel with the inner peripheral surface of the shell 3. The end member 7 or the bellows 6 is prevented from biting against the inner peripheral surface of the shell 3. It should be noted that the sliding member 16 is illustrated so that the pressure member 9 is not divided into a space 9 a on the outer peripheral side of the bellows 6 and a space 9 b on the upper and lower sides of the end member 7 in the figure. A pressure communicating portion is provided.

  A seal mounting portion 3c having an annular recess shape is provided on the inner peripheral surface of the end wall portion 3a of the shell 3, that is, the end surface portion 3b, and at the opening peripheral edge portion of the pressure introducing port 15, and an end face seal 21 is provided on the seal mounting portion 3c. Is installed.

  The end face seal 21 is configured as follows.

  That is, as shown in an enlarged view in FIG. 2, first, an annular seal member (also referred to as a lip seal) 22 made of a predetermined rubber-like elastic material is press-fitted into the seal mounting portion 3 c of the shell 3. An annular or cylindrical rigid member (also referred to as a ring or a pipe) 23 made of a predetermined metal, resin, or the like is disposed on the inner peripheral side of the ring. A rigid member mounting portion 3d having an annular step shape for press-fitting and fixing the rigid member 23 is provided on the inner peripheral side of the seal mounting portion 3c. According to the procedure of assembling and mounting the end face seal 21, it is preferable to first press the seal member 22 into the outer periphery of the rigid member 23 and then fit the rigid member 23 into the mounting portion 3d.

  First, the seal member 22 is provided with an annular base portion 22a that is press-fitted and fixed to the seal mounting portion 3c in a non-adhesive manner. An annular seal lip 22b (also referred to as an inner peripheral side seal lip or a first seal lip) 22b that is in contact with is integrally formed. An annular recess 22c is formed on the outer peripheral side of the seal lip 22b, and an outer peripheral side seal lip (also referred to as a second seal lip) that is always in close contact with the inner surface of the seal mounting portion 3c on the further outer peripheral side of the recess 22c. ) 22d is integrally formed.

  As shown in the drawing, the seal lip 22b is formed as an outwardly-shaped seal lip that is inclined radially outward from the base end portion to the tip end portion, and as shown in FIG. When it comes into contact with 7a, it is pushed by the pressure P of the pressure chamber 9, which is the sealing fluid pressure, and is pressed against this end face 7a to come into close contact. Therefore, the outer peripheral surface of the seal lip 22b is a pressure receiving surface. Further, two seal projections 22e and 22f each having an annular shape are provided concentrically at the tip of the seal lip 22b. As shown in FIG. 3, the seal projections 22e and 22f are respectively provided on the end member 7. Close to the end face 7a. As shown in FIG. 4, this is because the foreign matter 31 in the float is caught between any one of the seal projections 22e and the end surface 7a of the end member 7, and the seal between the seal projection 22e and the end surface 7a is sealed. Even if the performance is impaired, the other sealing projection 22f is in close contact with the end surface 7a over the entire circumference so that the sealing performance is ensured, and a multilayer of such sealing projections 22e and 22f is provided. By providing the structure, the sealing performance as the whole seal lip 22b is remarkably improved. The number of seal protrusions 22e and 22f formed is not limited to two but may be three or more. Furthermore, the seal lip 22b is in a non-contact free state shown in FIG. 2 so that the seal protrusions 22e and 22f are in intimate contact with the end surface 7a of the end member 7 when the end member 7 moves. The tip of the seal lip 22b is set so as to protrude toward the end member 7 from the end surface 3b of the shell 3 and the tip surface 23e of the rigid member 23 described later.

  The outer peripheral side seal lip 22d provided on the outer peripheral portion of the seal member 22 is pressed by the pressure P of the pressure chamber 9 and pressed against the inner side surface of the seal mounting portion 3c. As shown in FIG. 5, the seal lip 22d is directed radially outward so that the contact surface pressure can be locally increased to sufficiently seal the inner surface of the seal mounting portion 3c. An annular seal protrusion 22g that protrudes is provided.

  As described above, the rigid member 23 is formed in a cylindrical shape by a predetermined metal or resin, and the base end portion 23a thereof is press-fitted (tightened) into the rigid member mounting portion 3d of the shell 3, The pressure inlet 15 and the pressure chamber 9 are communicated with each other through the inner space. Further, the distal end portion 23b of the rigid member 23 on the end member 7 side is formed in a tapered taper shape or a trumpet shape. Along with this, the outer peripheral surface 23c of the distal end portion 23b also extends in a tapered shape or a trumpet shape. It is formed in a shape. The distal end portion 23b or the outer peripheral surface 23c is disposed on the inner peripheral side of the seal lip 22b of the seal member 22. Therefore, when the seal lip 22b is pushed by the high pressure on the pressure chamber 9 side and tries to reverse, the distal end portion 23b. Inversion is prevented by contact with the outer peripheral surface 23c. Therefore, in this way, the outer peripheral surface 23c of the distal end portion 23b functions to back up the seal lip 22b. In the free state of FIG. 2, a gap 24 of a predetermined size is set between the outer peripheral surface 23c of the tip end portion 23b and the inner peripheral surface of the seal lip 22b, and both members are not in contact with each other. The gap 24 may be omitted, and in this case, both members are always in contact with each other. The tip 23d of the tip 23b is rounded in cross section so as not to damage the rubber seal lip 22b. In addition, the portion supporting the seal lip 22b including the outer peripheral surface 23c of the tip end portion 23b is coated with resin or the like in consideration of preventing wear of the seal lip 22b due to contact, or the end portion of the rigid member 23 is resin You may decide to arrange | position the protection ring (not shown) which consists of etc. The end surface 23e of the tip 23b is formed in parallel with the end surface 3b of the shell 3, and the end surface 23e is flush with the end surface 3b of the shell 3 so that the actuating member 5 does not abut against it. It arrange | positions or it arrange | positions in the position which retracted from the end surface part 3b so that the action | operation member 5 may not contact | abut to this.

  The end face seal 21 configured as described above is configured so that the pressure in the pressure chamber 9 does not decrease below a predetermined value when the pressure in the pressure chamber 9 decreases as the pressure on the pressure pipe decreases. The sealing is characterized in that the above-described configuration provides the following operational effects.

  That is, first, the seal member 22 is mounted on the seal mounting portion 3c of the end surface portion 3b of the stationary shell 3, not on the side of the operating member 5 that moves during operation, and moves toward the end surface portion 3b. In a state where the end member 7 of the operating member 5 comes into contact with the end surface portion 3a of the shell 3 and stops, the seal lip 22b of the seal member 22 of the end surface seal 21 is pushed by the pressure P of the pressure chamber 9 which is the sealing fluid pressure. Therefore, since the sealing action is performed by being in close contact with the end surface 7a of the end member 7, the sealing is not performed in a state where the sealing member 22 is strongly sandwiched between the rigid members, but the sealing lip 22b of the sealing member 22 is provided. Sealing is performed in a state of being in close contact with the end surface 7a of the end member 7 that has already stopped with a predetermined contact pressure. Therefore, since the seal member 22 provided with the seal lip 22b is not strongly sandwiched between the rigid members in a compressed state, it is possible to prevent the seal member 22 from causing a sag phenomenon at an early stage. Therefore, stable sealing performance can be ensured over a long period of time.

  Further, on the inner peripheral side of the seal lip 22b of the seal member 22 formed in the outward shape, the outer peripheral surface of the distal end portion 23b of the rigid member 23 that is formed in a tapered shape in accordance with the shape of the seal lip 22b. Since 23c is arranged, the tip 23b or the outer peripheral surface 23c acts to back up the seal lip 22b. Therefore, since the seal lip 22b is prevented from being pushed by the high pressure on the pressure chamber 9 side and reversed to the low pressure side, that is, the inner peripheral side, the seal lip 22b is kept on the end surface 7a of the end member 7 in a stable state. Can be contacted. Therefore, sealing performance can be stabilized also from this point.

  Further, as shown in the figure, since the maximum outer diameter dimension of the outer peripheral surface 23c of the distal end portion 23b of the rigid member 23 formed in a tapered shape is set larger than the minimum inner diameter dimension of the seal member 22, The part 23b thru | or the outer peripheral surface 23c show | play the retaining action which prevents that the sealing member 22 remove | deviates from the seal mounting part 3c. Therefore, even if the rubber-like elastic seal member 22 is attached to the seal attachment portion 3c without being bonded, the seal member 22 does not come out of the seal attachment portion 3c, so that the adhesion (baking) operation at the time of attachment is omitted. It becomes possible to do. Therefore, it is possible to facilitate the mounting operation and provide the end face seal 21 that is advantageous in terms of cost.

  Furthermore, since a plurality of seal projections 22e and 22f are provided at the tip of the seal lip 22b and the seal lip 22b has a substantially multi-stage structure, a foreign matter is added to the sealing action by one seal projection. Even if troubles due to the biting of 31 or the like occur, the sealing action can be maintained by another sealing protrusion. Therefore, sealing performance can be stabilized also from this point. In this way, when the lip is substantially made into a plurality of stages, in the case where the lip is set to two stages, either one is set by setting the width (interval) of each stage longer than the length or diameter of the foreign matter 31. One stage maintains contact. In the case of three or more stages, the width (interval) of each stage is set to be the same as that of the two stages, or the entire width of the contact portion of the seal lip 22b is longer than the length or diameter of the foreign matter 31. By doing so, one of the steps maintains the contact state.

  Further, since the seal member 22 is provided with an inner peripheral side seal lip 22b and an outer peripheral side seal lip 22d in close contact with the inner surface of the seal mounting portion 3c, the end surface seal 21 and an end surface on which the end seal 21 is mounted are provided. It is possible to exhibit a good sealing action between the portions 3b (housing). Therefore, also from this point, the sealing performance can be improved.

  In the present invention, the movement of the actuating member 5 toward the end surface portion 3b is stopped by a structure in which the actuating member 5 is stopped by a stopper (not shown) in addition to being stopped by contacting the end surface portion 3b. May be. In this case, the stopper is constituted by, for example, a protrusion protruding from the end surface portion 3b toward the operating member 5, a spacer installed at the end surface portion 3b, and the like.

Sectional drawing of the accumulator equipped with the end face seal according to the embodiment of the present invention Enlarged cross section of end face seal Partially enlarged sectional view showing the operating state of the end seal Partially enlarged sectional view showing the operating state of the end seal Enlarged sectional view of the seal member Sectional view of accumulator with end face seal according to conventional example

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Accumulator 2 Housing 3 Shell 3a End wall part 3b End surface part 3c, 3d Mounting part 4 Lid member 5 Actuation member 6 Bellows 7 End member 7a, 23e End surface 8 Gas chamber 9 Pressure chamber 10 Inlet 11 Plug member 12 Packing 13 Attachment part 14 Threaded portion 15 Pressure inlet (fluid flow path)
15a, 23f Positioning part 15b Engagement part 16 Sliding member 21 End face seal 22 Seal member 22a Base part 22b, 22d Seal lip 22c Recessed part 22e, 22f, 22g Seal protrusion 23 Rigid member 23a Base end part 23b Tip part 23c Outer peripheral surface 23d Pointed end 24 Gap 31 Foreign object

Claims (2)

An end face seal (21) for sealing between the end face part (3b) and the actuating member (5) moving toward the end face part (3b),
A seal member (22) attached to the end face (3b);
The seal member (22) is pressed by the sealing fluid pressure when the operating member (5) stops by contact with the end face (3b) or stops by the stopper, and comes into close contact with the operating member (5). Having a sealing lip (22b),
An end face seal characterized in that a plurality of seal protrusions (22e) and (22f) that are in close contact with the actuating member (5) are provided at the tip of the seal lip (22b). The end face seal of claim 1,
The seal member (22) has an outer peripheral side seal lip (22d) in close contact with the inner surface of the seal mounting portion (3c) together with the seal lip (22b).

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