JP2017133540A - Sealing device and method of increasing interface of sealing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing device capable of increasing an interface of a seal lip portion without replacing a seal member itself, and a method of increasing an interface of the sealing device.SOLUTION: A sealing device includes: a housing 2 which has a shaft 3 and a shaft hole; a seal member which is disposed on an attaching surface 24 provided on one of these two members so as to be orthogonal to an axial direction, and composed of an annular supporting plate 11 and an annular seal lip portion 12 bulging out from a peripheral end portion 11a of the supporting plate 11 so as to diagonally contacts with the other member; a fixing member 7 which presses the supporting plate 11 toward the attaching surface 24 to fix the seal member 1; and a spacer member 8 which is sandwiched between the supporting plate 11 and the attaching surface 24, and deforms the supporting 11 pressed toward the attaching surface 24 with the fixing member 7 so as to incline in a direction increasing an interface of the seal lip portion 12 to the attaching surface 24.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a sealing device and a method for increasing the tightening allowance of the sealing device, and more particularly, to a sealing device and a method for increasing the tightening allowance of the sealing device that can increase the tightening allowance of the seal lip portion without replacing the seal member itself. .

  As a conventional sealing device, there is a rod sealing system for a hydraulic cylinder device shown in FIG. 8 (Patent Document 1).

  The rod sealing system 100 seals an annular gap 400 between a housing (cylinder) 200 of a hydraulic cylinder device and a shaft (rod) 300 inserted into a shaft hole 201 of the housing 200 so as to be capable of relative movement. The main seal 101 that prevents leakage of hydraulic oil in the housing 200 and the inside of the main seal 101 (on the hydraulic chamber B side of the housing 200) are arranged so that the hydraulic pressure from the hydraulic chamber B does not act directly on the main seal 101. And buffering 102 to be made. The dust seal 103 as a seal member is disposed on the outermost side (external space A side) of the rod sealing system 100 and has a function of preventing entry of foreign matters such as muddy water and dust from the external space A.

  The dust seal 103 has a seal lip portion 103a made of an elastic material such as rubber or urethane at a contact portion with the shaft 300. The seal lip 103a is brought into close contact with the surface of the shaft 300 by a predetermined tightening allowance, so that the sealed state of the annular gap 400 is maintained well.

JP 2006-29518 A

  In the sealing device, there is a case where the seal lip portion becomes sticky depending on the use time or the use temperature, and the tightening margin may be reduced. When the tightening allowance of the seal lip portion is reduced, the tightening force (surface pressure) on the mating member is lowered, so that dust resistance is lowered, and foreign matter such as muddy water and dust may enter the annular gap. In particular, urethane materials have poor resistance to settling, and settling is likely to occur when used for a long time or in a high temperature environment.

  In the conventional sealing device, if the tightening margin of the seal lip portion is reduced due to the settling, the only way to improve the sealing state is to replace the entire dust seal with a new one, which is costly.

  Then, this invention makes it a subject to provide the sealing device which can increase the interference of a seal lip part, without replacing | exchanging sealing member itself.

  Another object of the present invention is to provide a tightening margin increasing method for a sealing device that can increase the tightening margin of the seal lip portion without replacing the seal member itself.

  The other subject of this invention becomes clear by the following description.

  The above problems are solved by the following inventions.

1. The axis,
A housing having a shaft hole into which the shaft is inserted so as to be relatively movable;
One of the two members of the shaft and the housing is disposed on a mounting surface provided so as to be orthogonal to the axial direction, and an annular support plate and a peripheral end portion of the support plate from the peripheral member. An annular seal lip portion projecting so as to be in contact with the other member at an angle, and a seal member for sealing an annular gap between the two members by the seal lip portion;
A fixing member that fixes the seal member by pressing the support plate toward the mounting surface;
The support plate sandwiched between the support plate and the mounting surface and pressed toward the mounting surface by the fixing member in a direction to increase the tightening margin of the seal lip portion with respect to the mounting surface. A sealing device comprising: a spacer member that is deformed so as to be inclined.
2. 2. The sealing device according to claim 1, wherein the spacer member is formed in an annular shape by a plurality of arc-shaped members.
3. 3. The sealing device according to claim 1 or 2, wherein a peripheral edge of the attachment surface on the other member side is an inclined surface that is inclined along an inclination direction of the support plate.
4). An annular recess in which the support plate of the seal member is accommodated on an axial end surface of the one member;
4. The sealing device according to 1, 2, or 3, wherein the attachment surface is formed by a bottom surface of the annular recess.
5. The fixing member is a bolt;
The support plate has a plurality of through holes formed at intervals in the circumferential direction, and the shaft portion of the bolt is inserted into the through hole, and is pressed toward the mounting surface by the head of the bolt. The sealing device according to any one of 1 to 4, wherein the sealing device is fixed by being performed.
6). An annular support plate and the support are mounted on a mounting surface arranged so as to be orthogonal to the axial direction of one member of the shaft and a housing having a shaft hole into which the shaft is inserted so as to be relatively movable. A seal member formed of an annular seal lip portion protruding so as to be in contact with the other member of the two members obliquely from the peripheral end portion of the plate is pressed by the fixing member toward the mounting surface. After fixing the tip end of the seal lip part with the other member with a predetermined tightening margin to seal the annular gap between the two members,
When the tightening margin for the other member of the seal lip is increased, the mounting plate is pressed between the supporting plate and the mounting surface by the fixing member toward the mounting surface. A tightening margin increasing method for a sealing device, wherein the tightening margin for the other member of the seal lip portion is increased by sandwiching a spacer member that is deformed so as to be inclined with respect to the seal lip portion.

  ADVANTAGE OF THE INVENTION According to this invention, the sealing device which can increase the interference of a seal lip part can be provided, without replacing | exchanging a sealing member.

  In addition, according to the present invention, it is possible to provide a tightening margin increasing method of a sealing device that can increase the tightening margin of the seal lip portion without replacing the seal member.

Sectional drawing which shows an example of the rod sealing system to which the sealing device according to the present invention is applied. Sectional drawing which expands and shows the sealing device shown in FIG. 2 is an exploded perspective view of the sealing device shown in FIG. Sectional drawing which shows the state before giving interference margin increase in the sealing device shown in FIG. Sectional drawing which shows another example of the fixing member in this invention Sectional drawing which shows another example of the spacer member in this invention The figure explaining the experimental method using the sealing member in this invention Cross-sectional view of the main part showing a rod sealing system to which a conventional sealing device is applied

  Embodiments of the present invention will be described below with reference to the drawings.

  The embodiment shown below has shown the case where the sealing member of the sealing device which concerns on this invention and the sealing member increase method of a sealing device is applied to the dust seal in the rod sealing system of a hydraulic cylinder apparatus. 1 is a cross-sectional view of an essential part showing an example of a rod sealing system to which a sealing device according to the present invention is applied, FIG. 2 is an enlarged cross-sectional view of the sealing device shown in FIG. 1, and FIG. 4 is an exploded perspective view of the sealing device shown, and FIG. 4 is a cross-sectional view showing a state before the tightening margin is increased in the sealing device shown in FIG.

  The rod sealing system 10 seals an annular gap 4 between a housing (cylinder) 2 of a hydraulic cylinder device and a shaft (rod) 3 inserted into a shaft hole 21 of the housing 2 so as to be capable of relative movement. Here, the relative movement means that either or both of the housing 2 and the shaft 3 slide in the axial direction.

  In this rod sealing system 10, the dust seal 1 as a seal member in the present invention is disposed on the outer space A side that is the outermost side in the axial direction, and prevents intrusion of foreign matters such as muddy water and dust from the outer space A. It has the function to do. A main seal 5 for preventing leakage of hydraulic oil in the housing 2 to the hydraulic chamber B side from the dust seal 1, and an oil pressure from the hydraulic chamber B directly to the main seal 5 further axially inside the main seal 5. A buffering 6 is arranged so as not to act.

  The shaft hole 21 of the housing 2 has a large-diameter portion 22 formed at a larger diameter than a portion adjacent to the main seal 5 and the buffer ring 6 at the end on the outer space A side. An annular recess 23 is formed in the end surface 2 a of the external space A of the housing 2.

  The annular recess 23 is a part that accommodates and fixes the dust seal 1, and is formed in a concave shape that is coaxial with the shaft hole 21 from the end surface 2 a of the housing 2. The inner peripheral side of the annular recess 23 is connected to the large diameter portion 22. That is, the annular recess 23 is formed by further expanding the diameter of the outer space A side of the large diameter portion 22.

  The bottom surface of the annular recess 23 is disposed so as to be orthogonal to the axial direction of the housing 2 (the direction along line O in FIG. 1), and forms a mounting surface to which the dust seal 1 is fixed. Hereinafter, the bottom surface of the annular recess 23 is referred to as an attachment surface 24.

  The dust seal 1 includes a support plate 11 and a seal lip portion 12.

  The support plate 11 is an annular thin plate member formed of a metal plate such as SPCC (cold rolled steel plate) or a synthetic resin plate such as nylon. The outer diameter of the support plate 11 is slightly smaller than the inner diameter of the annular recess 23. Further, the inner diameter of the support plate 11 is larger than the diameter of the shaft hole 21 of the housing 2 and smaller than the diameter of the large diameter portion 22. Accordingly, the inner peripheral end 11 a of the support plate 11 protrudes from the annular recess 23 to the large diameter portion 22.

  A plurality of through holes 13 are formed in the support plate 11 at intervals in the circumferential direction. The through hole 13 is a fixing portion for fixing the dust seal 1 in the annular recess 23 by inserting a shaft portion of a bolt described later.

  The seal lip portion 12 is made of, for example, a rubber-like elastic material such as urethane resin, and projects in an annular shape so as to be in contact with the shaft 3 obliquely from the inner peripheral end portion 11a of the support plate 11. Specifically, the seal lip portion 12 is formed in a tapered shape toward the outer space A by projecting obliquely from the inner peripheral end portion 11a of the support plate 11 toward the shaft 3 side and toward the outer space A side. Is formed. Thereby, the front-end | tip part 12a of the seal lip | rip part 12 has a predetermined fastening margin, closely_contact | adheres to the outer peripheral surface of the axis | shaft 3, and seals the annular clearance 4 between the shaft hole 21 and the axis | shaft 3 of the housing 2.

  The dust seal 1 is fixed to the mounting surface 24 of the annular recess 23 by a bolt 7 which is an example of a fixing member. Specifically, the shaft portion 72 of the bolt 7 inserted into the through hole 13 of the support plate 11 is screwed into the bolt hole 25 provided in the mounting surface 24, and the head 71 of the bolt 7 holds the support plate 11. By pressing toward the mounting surface 24, the support plate 11 is sandwiched between the head 71 and the mounting surface 24, and the dust seal 1 is fixed to the mounting surface 24. The depth of the annular recess 23 is at least as large as the thickness of the support plate 11, and the support plate 11 of the dust seal 1 fixed by the bolt 7 is accommodated in the annular recess 23.

  Next, a configuration and method for increasing the tightening allowance of the dust seal 1 will be described.

  In order to increase the tightening allowance of the dust seal 1, the spacer member 8 is sandwiched between the support plate 11 and the mounting surface 24 of the dust seal 1.

  The spacer member 8 is an annular thin plate member made of a metal such as SPCC. The spacer member 8 shown in the present embodiment is formed to be narrower than the support plate 11, and is sandwiched between the outer peripheral end 11 b side of the support plate 11 and the mounting surface 24. The outer diameter of the spacer member 8 is substantially equal to the outer diameter of the support plate 11. Further, the inner diameter of the spacer member 8 is larger than the diameter of the portion where the through hole 13 of the support plate 11 is disposed. Therefore, the spacer member 8 is disposed on the outer side in the radial direction than the bolt hole 25 of the mounting surface 24.

  The spacer member 8 is sandwiched between the support plate 11 and the mounting surface 24 of the dust seal 1, and the support plate 11 is pressed and fixed toward the mounting surface 24 by the head 71 of the bolt 7. As shown in FIG. 2, the support plate 11 is deformed so as to be inclined with respect to the mounting surface 24. That is, while the spacer member 8 is sandwiched on the outer peripheral end portion 11b side of the support plate 11, the spacer member 8 does not exist on the inner peripheral end portion 11a side of the support plate 11, thereby The axial position of the outer peripheral end portion 11b is displaced toward the outer space A with respect to the inner peripheral end portion 11a, and the axial positions of the two are different.

  As a result, the support plate 11 is deformed so that the inner peripheral end portion 11a side is inclined toward the hydraulic chamber B side in the axial direction with respect to the mounting surface 24, and the seal lip portion 12 provided on the inner peripheral end portion 11a. Is tilted in the X1 direction toward the outer peripheral surface of the shaft 3. As a result, as shown in FIG. 4, compared to the case where the spacer member 8 is not sandwiched (initial state), the tightening allowance for the shaft 3 of the seal lip portion 12 is increased. The seal lip portion 12 is in close contact with the outer peripheral surface of the shaft 3 with increased tightening allowance.

  For this reason, as shown in FIG. 4, as a result of continuing to use the dust seal 1 fixed to the mounting surface 24 in the initial state where the spacer member 8 is not sandwiched, the seal lip portion 12 becomes sticky. In the case where the allowance for the shaft 3 of the tip end portion 12a is reduced by bending in the X2 direction, the spacer member 8 is sandwiched as shown in FIG. 2 to eliminate the need to replace the dust seal 1 itself. The fastening margin of the lip portion 12 can be increased.

  In addition, even if the seal lip portion 12 is set, it is not necessary to replace the dust seal 1 itself, so that the life of the dust seal 1 can be extended. The cost can also be reduced by reducing the replacement frequency of the dust seal 1.

  A specific method for increasing the fastening margin of the seal lip portion 12 by sandwiching the spacer member 8 can be performed as follows.

  As shown in FIG. 4, when the tightening margin is increased in the dust seal 1 in a state where the spacer member 8 is not sandwiched, the screw 7 is temporarily released to remove the support plate 11 from the annular recess 23. After that, as shown in FIG. 2, the spacer member 8 is sandwiched between the support plate 11 and the mounting surface 24, the bolt 7 is screwed again, and the support plate 11 is supported by the head 71 as the bolt 7 is tightened. Is pressed against the mounting surface 24, and the support plate 11 is deformed so as to be inclined with respect to the mounting surface 24 in a direction in which the tightening margin of the seal lip portion 12 is increased.

  The thickness of the spacer member 8 is adjusted by appropriately taking into consideration the diameter of the support plate 11, the diameter of the mounting surface 24, and the like according to the desired amount of inclination (amount of tightening allowance) of the support plate 11.

  As shown in FIG. 3, the spacer member 8 is preferably configured in an annular shape by a plurality of arc-shaped members 81. In the present embodiment, the two arcuate members 81, 81 that are halved are combined to form an annular shape, but may be three or more. By making each arcuate member 81 into an arc shape of 180 ° or less, each arcuate member 81 can be inserted from the radial direction as shown in the figure. For this reason, it is sufficient to remove only the dust seal 1 from the annular recess 23, and the spacer member 8 can be easily sandwiched between the support plate 11 and the mounting surface 24 without having to disassemble the entire rod sealing system 10.

  The peripheral edge on the inner peripheral side of the mounting surface 24 is preferably an inclined surface 24a along the direction in which the support plate 11 is inclined. That is, the peripheral edge portion on the inner peripheral side of the mounting surface 24 in the present embodiment is slightly inclined toward the hydraulic chamber B side in the axial direction. Thereby, the support plate 11 can be smoothly inclined along the inclined surface 24a, and the tightening allowance can be increased.

  The outer peripheral edge 24 b of the inclined surface 24 a passes through the center of the bolt hole 25. For this reason, when the support plate 11 is pressed toward the mounting surface 24 by the head 71 of the bolt 7 with the spacer member 8 being sandwiched, the inner peripheral end 11a side of the support plate 11 is supported with the spacer member 8 as a fulcrum. It can be inclined more smoothly.

  Further, as shown in the present embodiment, since the spacer member 8 is disposed in the annular recess 23, the spacer member 8 is prevented from moving radially outward by the peripheral wall surface 23 a of the annular recess 23. Thereby, it is possible to prevent the spacer member 8 from separating in the radial direction.

  Although the fixing member shown in the present embodiment uses only the bolt 7, for example, as shown in FIG. 5, an additional fixing ring 9 may be used in addition to the bolt 7.

  The fixing ring 9 is fixed to the end surface 2 a by screwing the bolt 7 into a bolt hole 26 provided in the end surface 2 a of the housing 2. On the inner peripheral side of the fixing ring 9, an appropriate number of protrusions 91 that press the support plate 11 of the dust seal 1 toward the mounting surface 24 are provided. Therefore, the fixing ring 9 is attached to the end surface 2a with the bolt 7, and the support member 11 is pressed toward the attachment surface 24 by the protrusion 91 as the bolt 7 is tightened, so that the spacer member 8 is attached in the same manner as in FIG. The clamped support plate 11 can be inclined to increase the tightening allowance by the seal lip portion 12.

  The fixing ring 9 may be configured to press the support plate 11 with an annular protrusion instead of the protrusion 91. Further, the fixing ring 9 may be fixed by being screwed to the end surface 2 a of the housing 2 without using the bolt 7.

  In addition, as shown in FIG. 6, the spacer member 8 in the present invention may be formed in a wedge shape by making the surface 8 a on the side in contact with the support plate 11 downwardly inclined toward the inner peripheral side. Good. Accordingly, when increasing the tightening allowance, the support plate 11 can be inclined more smoothly.

  In the above embodiment, the case where the dust seal 1 is provided on the housing 2 side having the shaft hole 21 has been described. However, the sealing device and the method for increasing the tightening allowance of the sealing device according to the present invention provide the dust seal 1 on the shaft 3 side. It may be. In this case, the configuration of the inner peripheral side and the outer peripheral side in the embodiment described above is reversed.

  Further, the sealing device and the method for increasing the tightening allowance of the sealing device according to the present invention are not limited to those applied to the dust seal of the rod sealing system of the hydraulic cylinder device described above, and the shaft and the shaft are inserted so as to be capable of relative movement. The annular gap between the housing having the shaft hole can be widely applied to a sealing device that seals with a seal member.

  The effects of the present invention are illustrated below by examples.

A dust seal having the following specifications was produced.
・ Support plate thickness: 0.6mm
Outer diameter: φ114mm
Inner diameter: φ103mm
Material: SPCC
・ Seal lip inner diameter (minimum diameter): φ98.6mm
Maximum height in the axial direction: 3.6 mm

  As shown in FIG. 6, the center portion of the support plate in the width direction (corresponding to the portion of the through hole 13) is sandwiched between the fixed walls, and the movable wall is brought into contact with the lower side of the outer peripheral end portion as a substitute for the spacer member. By moving the movable wall upward by a predetermined amount, an inclination amount ΔT (see FIG. 2) of the seal lip portion provided at the inner peripheral end of the support plate was confirmed by FEM analysis. The amount of movement of the movable wall corresponds to the thickness of the spacer member.

  As a result, when the amount of movement of the movable wall is 0.1 mm, ΔT = 0.04 mm, the amount of movement of the movable wall is 0.3 mm, ΔT = 0.16 mm, and the amount of movement of the movable wall is 0.5 mm. ΔT = 0.33 mm, and it can be seen that the support plate can be inclined by inserting the spacer member, and the tightening margin of the seal lip portion can be increased.

1: Dust seal (seal member)
11: support plate 11a: inner peripheral end portion 11b: outer peripheral end portion 12: seal lip portion 12a: tip portion 13: through hole 2: housing (one member)
2a: End surface 21: Shaft hole 22: Large diameter portion 23: Annular recess 23a: Inner peripheral wall 24: Mounting surface 24a: Inclined surface 25: Bolt hole 26: Bolt hole 3: Shaft (the other member)
4: Annular gap 5: Main seal 6: Buffer ring 7: Bolt (fixing member)
71: Head 72: Shaft 8: Spacer member 81: Arc-shaped member 9: Fixing ring (fixing member)
91: Projection 10: Rod sealing system

Claims (6)

The axis,
A housing having a shaft hole into which the shaft is inserted so as to be relatively movable in the axial direction;
One of the two members of the shaft and the housing is disposed on a mounting surface provided so as to be orthogonal to the axial direction, and an annular support plate and a peripheral end portion of the support plate from the peripheral member. An annular seal lip portion projecting so as to be in contact with the other member at an angle, and a seal member for sealing an annular gap between the two members by the seal lip portion;
A fixing member that fixes the seal member by pressing the support plate toward the mounting surface;
The support plate sandwiched between the support plate and the mounting surface and pressed toward the mounting surface by the fixing member in a direction to increase the tightening margin of the seal lip portion with respect to the mounting surface. A sealing device comprising: a spacer member that is deformed so as to be inclined.   The sealing device according to claim 1, wherein the spacer member is formed in an annular shape by a plurality of arc-shaped members.   The sealing device according to claim 1, wherein a peripheral edge of the mounting surface on the other member side is an inclined surface that is inclined along an inclination direction of the support plate. An annular recess in which the support plate of the seal member is accommodated on an axial end surface of the one member;
The sealing device according to claim 1, wherein the attachment surface is formed by a bottom surface of the annular recess. The fixing member is a bolt;
The support plate has a plurality of through holes formed at intervals in the circumferential direction, and the shaft portion of the bolt is inserted into the through hole, and is pressed toward the mounting surface by the head of the bolt. The sealing device according to claim 1, wherein the sealing device is fixed by being performed. An annular support plate and the support are mounted on a mounting surface arranged so as to be orthogonal to the axial direction of one member of the shaft and a housing having a shaft hole into which the shaft is inserted so as to be relatively movable. A seal member formed of an annular seal lip portion protruding so as to be in contact with the other member of the two members obliquely from the peripheral end portion of the plate is pressed by the fixing member toward the mounting surface. After fixing the tip end of the seal lip part with the other member with a predetermined tightening margin to seal the annular gap between the two members,
When the tightening margin for the other member of the seal lip is increased, the mounting plate is pressed between the supporting plate and the mounting surface by the fixing member toward the mounting surface. A tightening margin increasing method for a sealing device, wherein the tightening margin for the other member of the seal lip portion is increased by sandwiching a spacer member that is deformed so as to be inclined with respect to the seal lip portion.

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