JPH056452Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a sealing device that is installed between two members that move relative to each other, such as a cylinder and a piston.

[Conventional technology]

Conventionally, as shown in FIG. 5, an annular groove 13 having a rectangular cross section is formed in one of the two members 11 and 12 that move relative to each other, and the other member 12 slides into the annular groove 13. A sealing device equipped with a seal ring 14 made of synthetic resin is known.

[The problem that the idea aims to solve]

In the above sealing device, the cross-sectional shape of the seal ring 14 is configured to be a simple rectangle, and the contact pressure It has become a thing that has limitations.

[Means to solve the problem]

In view of the above points, the present invention has been devised to actively unevenly distribute the contact pressure of the sliding parts to improve sealing performance. In a sealing device in which an annular groove is formed in one of two members, and a synthetic resin seal ring is attached to the annular groove in sliding contact with the other member, approximately at the center of the groove bottom of the annular groove. An annular protrusion having a tapered slope on the pressure side is formed, and a tapered slope is provided at both axial ends of the sliding surface side.The seal ring has tapered slopes on both ends of the sliding contact surface side. An annular recess with a corresponding tapered slope is formed, the annular projection is engaged with the annular recess, and a support ring or support projection is formed so that the opposite end surface of the seal ring does not come into contact with the side wall of the annular groove. The present invention provides a sealing device in which a tapered slope corresponding to the slope provided on the opposite pressure side of the seal ring is formed on the support ring or the support protrusion, which is supported by the seal ring and does not come into contact with the other member.

[Effect]

When pressure is applied to the seal ring, the seal ring comes to rest on the annular protrusion at the engagement part between the annular recess and the annular protrusion, and the part of the contact surface close to the pressure side is strongly pressed against the mating material (the other member). Press to increase the contact pressure on the part. On the other hand, the seal ring comes to rest on the support ring or support protrusion toward the opposite side (groove bottom side) on the anti-pressure side, reducing the contact pressure on the part of the contact surface far from the pressure side. . As a result, the contact pressure is always unevenly distributed on the sliding contact surface, and the contact pressure can be locally set to be large in the area close to the pressure side, thereby improving the sealing performance.

〔Example〕

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

In FIG. 1, numerals 1 and 2 indicate two members that move relative to each other like a piston and a cylinder, and one member 1 has an annular groove 3 with a rectangular cross section formed in the center of the groove bottom, tapered toward the pressure P side. An annular projection 4 having a slope 4a is formed. Reference numeral 5 denotes a seal ring made of synthetic resin, which has tapered slopes 5a and 5b formed backwards at both ends in the axial direction on the sliding surface 5c side that slides on the peripheral surface 2a of the other member 2. An annular recess 6 having a tapered slope 6a corresponding to the slope 4a of the annular protrusion 4 is formed on the peripheral surface of the anti-sliding surface of the ring 5. The annular recess 6 and the annular projection 4 engage with each other. Reference numeral 7 indicates that the anti-pressure side end surface 5d of the seal ring 5 is connected to the side wall 3 of the annular groove 3.
The support ring 7 is shown supporting the seal ring 7 so as not to come into direct contact with the support ring 7, and the support ring 7 is formed with a tapered slope 7a corresponding to the slope 5b provided on the opposite pressure side of the seal ring 5. The support ring 7
is formed of metal or synthetic resin with a large elastic modulus to a size that does not directly contact the peripheral surface 2a of the other member 2.

In Figure 1, there is a pressure P on the left side of the diagram, and this pressure P
This shows a state in which the seal ring 5 and the support ring 7 are pressed toward the right. Due to the action of this pressure P, the seal ring 5 first has slopes 4a and 6 at the engagement portion between the annular recess 6 and the annular protrusion 4.
A contact with each other generates an upward force A in the drawing, which strongly presses a portion of the sliding surface 5c close to the pressure P side against the circumferential surface 2a of the other member 2, increasing the contact pressure at that portion. On the other hand, the seal ring 5 has an inclined surface 5b at the engagement portion with respect to the support ring 7.
7a come into contact with each other and a force B is generated in the vertical direction in the figure.
The contact pressure of a portion of the sliding surface 5c far from the pressure P side is reduced. As a result, a force acting on the seal ring 5 as a whole tends to rotate clockwise in the figure, and a contact pressure Y is always unevenly distributed on the sliding surface 5c.
The sealing performance can be improved by locally increasing the contact pressure in the area close to the pressure P side compared to the conventional example.
In order to ensure the effect of this force, in the seal ring 5, which has a basically bilaterally symmetrical shape, the end surface 6b of the annular recess 6 is formed on the opposite pressure side from the axial center 5c' of the sliding surface 5c. In the attitude shown in FIG. 1, the end surface 6b of the annular projection 6 is
It is desirable that it be approximately aligned with c' in the axial direction.

The support ring 7 can be replaced with a support protrusion 8 integrally provided on one member 1, as shown in FIG. The support projection 8 is provided with a tapered slope 8a similarly to the support ring 7. In this case, the seal ring 5 against the annular groove 3
In order to enable or facilitate the fitting of the two parts, one part 1 is molded separately into two parts indicated by 1a and 1b.

1 and 2 show a so-called single-pressure type sealing device, whereas FIGS. 3 and 4 show a double-pressure type sealing device corresponding to FIG. 1 or 2, respectively. Projection 4, annular recess 6, support ring 7, support projection 8, etc. slopes 4a, 6a, 7a, 8
Everything including a is constructed symmetrically in the axial direction.

[Effect of idea]

As explained above, the sealing device of the present invention actively unevenly distributes the contact pressure on the sliding surface, and in particular locally sets a large contact pressure on the area near the pressure side of the contact surface to improve sealing performance. can.

[Brief explanation of the drawing]

1 to 4 are sectional views of main parts of a sealing device according to an embodiment of the present invention, and FIG. 5 is a sectional view of main parts of a conventional sealing device. 1, 1a, 1b...one member, 2...other member, 2a...peripheral surface, 3... annular groove, 3a...side wall, 4... annular projection, 4a, 5a, 5b, 6a,
7a, 8a... slope, 4b, 6b... end surface, 5...
...Seal ring, 5c... Sliding surface, 5c'... Axial center of sliding surface, 6... Annular recess, 7... Support ring, 8... Support protrusion.

Claims (1)

[Scope of utility model registration request] Move relative to each other like a cylinder and piston 2
In a sealing device in which an annular groove 3 is formed in one of the members 1 and 2, and a synthetic resin seal ring 5 is attached to the annular groove 3 in sliding contact with the other member 2, the annular groove The seal ring 5 has an annular protrusion 4 having a tapered slope 4a on the pressure P side at approximately the center of the groove bottom of the seal ring 3, and tapered slopes 5a and 5b at both ends in the axial direction on the sliding surface 5c side. An annular recess 6 having a tapered slope 6a corresponding to the slope 4a of the annular protrusion 4 is formed on the circumferential surface on the anti-sliding surface side, and the annular recess 6 and the annular protrusion 4 are engaged, and the seal ring 5 is attached to a support ring 7 so that its anti-pressure side end surface 5d does not contact the side wall 3a of the annular groove 3.
Alternatively, the support ring 7 or the support projection 8, which is supported by the support protrusion 8 and does not come into contact with the other member 2, has tapered slopes 7a, 8a corresponding to the slope 5b provided on the opposite pressure side of the seal ring 5. A sealing device characterized by forming: