JP2009210113A - Seal mechanism, and backup ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve high-pressure sealing performance of a seal mechanism using both a backup ring and an O-ring. <P>SOLUTION: In this seal mechanism 10, the O-ring 40 and the backup ring 50 are housed in a ring housing groove 22 of a shaft 20. In a high-pressure environment, the O-ring 40 receives pressure from the high-pressure side, and abuts on an inclined surface 54 of a projecting part 53 to expand the projecting part 53 while being compressed by being pressed toward the backup ring 50, and while making a ring center part abut on an abutting part 51 of the backup ring 50. Thereby, the projecting part 53 expands to close a space 33 on the low-pressure side to receive the O-ring 40, and prevents the O-ring 40 from projecting to the space 33 on the low-pressure side. In this case, since the projecting part 53 is formed of a hard elastic material relative to that of the abutting part 51, the projecting part 53 further surely keeps the expanded shape. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a seal mechanism that seals between two opposing members, and more particularly, to a seal mechanism that houses a seal member made of a compressible elastic material and a backup ring in a seal housing groove.

  In this type of sealing mechanism, it is proposed that when a seal member and a backup ring are accommodated in the seal accommodation groove, the seal performance is improved by suppressing protrusion of a general O-ring as a seal member. (For example, patent document 1 etc.).

JP 2006-336835 A Japanese Patent Laid-Open No. 8-200501

  In these patent documents, not only the backup ring and the O ring are arranged side by side and accommodated in the seal accommodation groove, but also the protrusion of the O ring is suppressed by devising the shape of the backup ring.

  However, in recent years, for example, it has been required to increase the gas filling efficiency in a high-pressure tank. This is because in a fuel cell vehicle, if the charging efficiency of a high-pressure tank of a fuel gas such as hydrogen gas to be mounted becomes high, the travelable distance increases due to an increase in the gas filling amount. For these reasons, the sealing mechanism is being required to ensure sealing performance in a higher pressure environment.

  In view of the above-described problems, an object of the present invention is to improve the high-pressure sealability of a seal mechanism using both a backup ring and an O-ring.

  In order to achieve at least a part of the above object, the present invention adopts the following configuration.

[Application 1: Sealing mechanism]
A sealing mechanism that seals between two opposing members,
An annular seal member made of a compressible elastic material and an annular backup ring are placed in a seal receiving groove formed in a recess in at least one of the two members so that the backup ring is positioned on the low pressure side. To house,
The backup ring is
The contact portion with which the central portion of the seal member abuts and the projecting portion that is integrated with the contact portion at the upper and lower peripheral edges of the corresponding contact portion and protrudes from the upper and lower peripheral edges toward the seal member are compressed by compression. The gist of the invention is that it is formed of a hard and soft elastic material having a different degree of development, and the abutting portion is formed of a soft elastic material and the protruding portion is formed of a hard elastic material.

  In the sealing mechanism configured as described above, the backup ring is located on the low pressure side and the seal member is located on the high pressure side of the seal member and the backup ring accommodated in the seal accommodation groove. From such a positional relationship, when the seal by the seal mechanism is in a high-pressure environment, the seal member is pushed to the backup ring side so that the central portion abuts against the contact portion of the backup ring, and the upper and lower peripheral edges of the contact portion. In this way, the protrusions are also brought into contact with the protrusions protruding from the upper and lower peripheral edges toward the seal member in an integrated manner with the contact parts, and the protrusions are widened. Such spreading of the protruding portion prevents the sealing member from being caught in the gap between the members to be sealed by receiving the sealing member. In the sealing mechanism configured as described above, the protrusion is formed of a hard elastic material after being integrated with the contact portion at the upper and lower peripheral edges of the contact portion, so that the shape of the protrusion that has spread as described above is maintained. Increased properties. For this reason, since the effectiveness of preventing the seal member from protruding into the gap between the members to be sealed increases, the sealing performance based on the prevention of the seal member from protruding can be further improved. In this case, when forming the abutting portion and the protruding portion of the hard and soft elastic material, the hard and soft elastic materials having the same elastic material and using the hard and soft elastic materials or the degree of elasticity by compression are different. Various types of elastic materials can be used.

  The sealing mechanism described above can be configured as follows. For example, the protruding portion of the backup ring can be protruded from the upper and lower peripheral edges surrounding the contact portion in three directions including the upper and lower peripheral edges. By doing so, the portions of the protruding portions protruding from the upper and lower peripheral edges of the contact portion are connected with the contact portion interposed therebetween, so that the contact portion and the protrusion portion are less likely to be peeled off. The effectiveness of improving the performance increases.

  In addition, if the seal member is an O-ring used for sealing high-pressure gas, it can be easily used in combination with a backup ring.

[Application 2: Backup ring]
An annular backup ring that is housed and used in a seal housing groove together with an annular seal member made of a compressible elastic material,
An abutting portion with which a central portion of the seal member abuts when accommodated in the seal accommodating groove;
A projecting portion that is integral with the abutting portion at the upper and lower peripheral edges of the abutting portion and protrudes toward the seal member from the upper and lower peripheral edges;
The abutting portion and the protruding portion are formed of a hard and soft elastic material having different degrees of elasticity by compression, the abutting portion is formed of a soft elastic material, and the protruding portion is formed of a hard elastic material. The gist is that it is formed.

  In the backup ring having the above-described configuration, it is possible to easily realize a seal mechanism that can exhibit high sealing performance under the high-pressure environment as described above by being housed in the seal housing groove together with the annular seal member.

  Hereinafter, embodiments of the present invention will be described based on examples. FIG. 1 is an explanatory diagram showing a partially enlarged state of a seal in a seal mechanism 10 as an embodiment of the present invention, and FIG. 2 is an explanatory diagram showing a partially enlarged configuration of a backup ring 50 used in the seal mechanism 10. FIG. 3 is an explanatory view for explaining a ring crushing margin and the like when the O-ring 40 is accommodated in the ring accommodating groove 22.

  As shown in the figure, the seal mechanism 10 of this embodiment includes a shaft 20, a mounting body 30 to be mounted, an O-ring 40 made of a compressible elastic material such as a rubber material, and a backup ring 50 described later. Prepare. The seal mechanism 10 is inserted into the insertion hole 32 of the mounting body 30 to face the body 20 and the mounting body 30, more specifically, the outer peripheral surface of the shaft 20 and the inner peripheral surface of the insertion hole 32 of the mounting body 30. Is sealed with an O-ring 40 and a backup ring 50. The shaft 20 has an outer diameter that takes into account the fitting tolerance with respect to the insertion hole 32, and includes a ring receiving groove 22 that is recessed in the outer periphery thereof.

  The ring housing groove 22 accommodates the O-ring 40 and the backup ring 50 side by side, and accommodates the O-ring in a compressed state by crushing. Therefore, the dimensions of the ring housing groove 22 are determined as shown in FIG. . Here, the diameter of the O-ring 40 is D, the groove bottom radius of the ring receiving groove 22 with which the O-ring 40 is in contact is R1, and the radius of the insertion hole 32 with which the O-ring 40 is in contact is R2. Then, when sealing the shaft 20 and the mounting body 30, the O-ring 40 is crushed and compressed because it is accommodated in the ring accommodation groove 22 and is in contact with the insertion hole 32. Is expressed by the following equation.

  H = (D- (R1-R2)) / Dx100

  In this embodiment, since the seal resistance of the shaft 20 and the mounting body 30 by the O-ring 40 and the backup ring 50 is about 50 to 75 MPa, the diameter D and the ring of the O-ring 40 are set so that the crushing rate H is 30% or more. The groove bottom radius R1 of the receiving groove 22 and the radius R2 of the insertion hole 32 were determined.

  As shown in detail in FIG. 2, the backup ring 50 has a central region in the cross section in the central axis direction as a concave shape, and the concave portion serves as a contact portion 51 with which the central portion of the O-ring 40 contacts. The contact portion 51 has a rectangular cross section when viewed alone, and the upper and lower peripheral edges and one side surface (the left side surface in FIG. 2) are surrounded by the covering portion 52. The covering portion 52 is integrated with the contact portion 51 at the upper and lower peripheral edges and one side surface, and includes a protruding portion 53 that protrudes from the upper and lower peripheral edges of the contact portion with the contact portion 51 interposed therebetween. As shown in the enlarged view, the protruding portion 53 includes a jaw portion 53a at the protruding base portion, and the contact portion 51 is pressed by the jaw portion 53a.

  The backup ring 50 having such a configuration is formed by using a compressible elastic material (for example, rubber material) that is commonly used as an existing backup ring, and this elastic material is a hard and soft elastic material having different degrees of elasticity by compression. is there. In the backup ring 50, the contact portion 51 is formed of a soft elastic material, and the covering portion 52 is formed of a hard elastic material including the protruding portion 53. In order to form the backup ring 50 using different materials in this manner, the so-called two-color molding method using a mold is used to connect the contact portion 51 and the cover portion 52, and the cover portion 52 sets the contact portion 51. In addition to surrounding, the contact portion 51 and the covering portion 52 may be formed in advance, and then the contact portion 51 may be surrounded by the covering portion 52 so as to be integrated. In this embodiment, the same rubber material, for example, ethylene propylene rubber (EPDM) or silicon rubber, is used to form the contact portion 51 and the protruding portion 53, and the same rubber material is used by adjusting the degree of vulcanization. However, it was made of the same hard and soft rubber material with different degrees of impact by compression. That is, the covering portion 52 including the protruding portion 53 is formed of soft EPDM or silicon rubber, and the contact portion 51 is formed of soft EPDM or silicon rubber.

  Returning to FIG. 1, the state of sealing between the mounting body 30 and the shaft 20 will be described. In the state where the shaft 20 is inserted into the insertion hole 32 of the mounting body 30, the pressure differs between the front and rear of the shaft 20 for the purpose of achieving high-pressure sealing between the O-ring 40 and the backup ring 50. For example, if the left side in FIG. 1 is the high pressure side, the O ring 40 and the backup ring 50 are accommodated in the ring so that the backup ring 50 is located on the low pressure side and the O ring 40 is located on the high pressure side. It is accommodated in the groove 22. In this case, the backup ring 50 is accommodated such that the covering portion 52 is in contact with the groove side surface 22 a of the ring accommodation groove 22. The O-ring 40 receives pressure from the high-pressure side and moves to the backup ring 50 side, and makes the central portion of the ring cross section abut against the abutting portion 51. Since the O-ring 40 has already been compressed in the ring housing groove 22 at the crushing rate H described above, the O-ring 40 exhibits a high-pressure sealing property between the shaft 20 and the mounting body 30 in combination with the backup ring 50.

  Next, the state of sealing by the sealing mechanism 10 under a high pressure environment will be described. FIG. 4 is an explanatory view for schematically explaining the behavior of the O-ring 40 and the backup ring 50 under a high-pressure environment. For example, when the shaft 20 and the mounting body 30 are components of a valve of a high-pressure tank, the sealing mechanism 10 is in a state of gas filling at a high pressure into the tank or a state where gas filling at a predetermined high pressure has already been completed. The seal by is placed under a high pressure environment.

  Under such a high-pressure environment, the O-ring 40 receives pressure from the high-pressure side and is compressed by being pushed toward the backup ring 50 as shown in FIG. Abut. Since this abutment is performed with a stronger force than before the high pressure environment, the O-ring 40 also abuts on the inclined surface 54 of the projecting portion 53 projecting from the upper and lower peripheral edges of the abutting portion 51. Spread 53. At this time, the projecting portion 53 spreads so as to close the gap 33 between the insertion hole 32 of the mounting body 30 and the shaft 20 on the low pressure side, and thus the projecting portion 53 thus expanded receives the O-ring 40. This O-ring 40 is prevented from protruding into the gap 33 on the low pressure side. In the seal mechanism 10 of the present embodiment, the protrusion 53 in the backup ring 50 is integrated with the contact portion 51 at the upper and lower peripheral edges of the contact portion 51, and as described above, the hard / soft EPDM or the like Since it formed from rubber materials (elastic material), such as silicon rubber, the shape maintenance characteristic of the protrusion part 53 expanded as mentioned above increases. For this reason, since the protrusion of the O-ring 40 to the gap 33 on the low-pressure side can be served with high effectiveness, the sealing performance based on prevention of the protrusion of the O-ring 40 can be further improved.

  Moreover, in the sealing mechanism 10 of the present embodiment, the protruding portion 53 of the backup ring 50 is made continuous with the covering portion 52, and the abutting portion 51 is surrounded by the protruding portions 53 and 52 in three directions including the upper and lower peripheral edges. Then, the protruding portion 53 was protruded from the upper and lower peripheral edges of the contact portion 51. Therefore, since each protrusion part 53 protruded from the up-and-down periphery of the contact part 51 is connected on both sides of the contact part 51, peeling of the contact part 51 and the protrusion part 53 can be made difficult to occur. As a result, the reliability of maintaining the shape of the protrusion 53 is enhanced, and the effectiveness of improving the sealing performance under a high pressure environment is also enhanced.

  In the present embodiment, the O-ring 40 used in combination with the backup ring 50 can be an existing one, which is convenient.

  Next, a modified example of the seal mechanism 10 will be described. FIG. 5 is a view corresponding to FIG. 1 and is an explanatory view showing a modified seal mechanism 10 that seals on the mounting body 30 side. In the seal mechanism 10 of this modification, the ring accommodation groove 22 is formed in the insertion hole 32 of the mounting body 30 into which the shaft 20 is inserted, and the O-ring 40 and the backup ring 50 are accommodated in the accommodation groove. Also with the seal mechanism 10 of the modified example shown in FIG. 5, a high-pressure seal can be achieved with high reliability.

  FIG. 6 is an explanatory view showing a seal mechanism 10 according to another modified example, and FIG. 7 is a view corresponding to FIG. 2, and is an explanatory view showing a configuration of a backup ring 50A used in this modified example. The seal mechanism 10 of this modified example is characterized in that when two members are surface-bonded, a high-pressure seal is achieved at the joint surface. As shown in the figure, the seal mechanism 10 of this modification includes a lower body 60 and an upper body 70 that are joined side by side, and seals the through holes 62 and 72 of the upper and lower bodies on the high pressure side with the body joint surface. To do. For this reason, the ring housing groove 22 is provided in the upper surface of the lower body 60 so as to be recessed in an annular shape so as to surround the through hole 62. The sealing mechanism 10 has the lower surface of the upper body 70 joined to the lower surface of the lower body 60 so that the O-ring 40 and the backup ring 50A are positioned so that the O-ring 40 is positioned on the high-pressure through hole 62 side. It accommodates in the accommodation groove | channel 22 and aims at a high pressure seal. In this case, in this modification, the O-ring 40 and the backup ring 50 are accommodated in the ring accommodation groove 22 so as to surround the through-hole in order to achieve a high-pressure seal around the through-hole 62. Therefore, as shown in FIG. 7, the backup ring 50 </ b> A includes the covering portion 52 on the outside and directs the protruding portion 53 toward the center, and protrudes the protruding portion 53 from the upper and lower peripheral edges of the contact portion 51. The high-pressure seal can be achieved with high reliability also by the seal mechanism 10 of the modification shown in FIG.

  As mentioned above, although the embodiment of the present invention has been described in the embodiments, the present invention is not limited to the above-described embodiments and modifications, and can be implemented in various modes without departing from the gist thereof. Is possible. For example, in the above-described embodiment, the contact portion 51 and the protruding portion 53 are formed of the same rubber material (EPDM, silicon rubber, etc.), but the same hard and soft rubber material having different degrees of impact by compression. However, you may make it form the contact part 51 and the protrusion part 53, using the hard and soft different types of rubber material from which the degree of the elasticity by compression differs.

It is explanatory drawing which partially enlarges and shows the mode of the seal in the seal mechanism 10 as an Example of this invention. FIG. 3 is an explanatory diagram showing a partially enlarged configuration of a backup ring 50 used in the seal mechanism 10. It is explanatory drawing explaining the ring crushing amount etc. at the time of accommodating O-ring 40 in the ring accommodation groove | channel 22. FIG. It is explanatory drawing which illustrates typically the behavior of the O-ring 40 and the backup ring 50 in a high-pressure environment. FIG. 2 is an explanatory view showing a seal mechanism 10 of a modified example that is equivalent to FIG. 1 and that seals on the mounting body 30 side. It is explanatory drawing which shows the seal mechanism 10 of the other modification. FIG. 9 is an explanatory diagram showing a configuration of a backup ring 50A used in another modification, corresponding to FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Seal mechanism 20 ... Shaft 22 ... Ring accommodation groove | channel 22a ... Groove side surface 30 ... Mounting body 32 ... Insertion hole 33 ... Gap 40 ... O-ring 50 ... Backup ring 50A ... Backup ring 51 ... Contact part 52 ... Covering part 53 ... Protruding part 53a ... Jaw part 54 ... Inclined surface 60 ... Lower body 62 ... Through hole 70 ... Upper body

Claims (4)

A sealing mechanism that seals between two opposing members,
An annular seal member made of a compressible elastic material and an annular backup ring are placed in a seal receiving groove formed in a recess in at least one of the two members so that the backup ring is positioned on the low pressure side. To house,
The backup ring is
The contact portion with which the central portion of the seal member abuts and the projecting portion that is integrated with the contact portion at the upper and lower peripheral edges of the corresponding contact portion and protrudes from the upper and lower peripheral edges toward the seal member are compressed by compression. A sealing mechanism formed of a hard and soft elastic material having different degrees of firing, wherein the contact portion is formed of a soft elastic material, and the protruding portion is formed of a hard elastic material.   The seal mechanism according to claim 1, wherein the protruding portion of the backup ring surrounds the contact portion in three directions including the upper and lower peripheral edges and protrudes from the upper and lower peripheral edges.   The seal mechanism according to claim 1 or 2, wherein the seal member is an O-ring used for sealing high-pressure gas. An annular backup ring that is housed and used in a seal housing groove together with an annular seal member made of a compressible elastic material,
An abutting portion with which a central portion of the seal member abuts when accommodated in the seal accommodating groove;
A projecting portion that is integral with the abutting portion at the upper and lower peripheral edges of the abutting portion and protrudes toward the seal member from the upper and lower peripheral edges;
The abutting portion and the protruding portion are formed of a hard and soft elastic material having different degrees of elasticity by compression, the abutting portion is formed of a soft elastic material, and the protruding portion is formed of a hard elastic material. Forming a backup ring.

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