JP7688263B2 - Seal Structure - Google Patents

Description

The present invention relates to a sealing structure, and more specifically, to a compact sealing structure that can absorb longitudinal displacement of the pipe body while ensuring sealing at the connection between the pipe body and the mounting part that are connected via a joint device.

Pipes are used by connecting them to various objects. Various sealing structures have been proposed to connect pipes to objects while ensuring a seal at the connection between the pipe and the object (see, for example, Patent Document 1). In the sealing structure shown in Figure 10 of Patent Document 1, a pipe is inserted into a through sleeve that penetrates the wall of a building. A sealing device protrudes from the outdoor side of the wall, covering the outer periphery of the pipe and fixing it to the wall. This sealing device has a laminated rubber flange consisting of a cylindrical elastic ring and a cylindrical reinforcing ring that are coaxial with the pipe.

In this sealing device, each cylindrical elastic ring undergoes shear deformation, causing the laminated rubber flange to elastically deform, thereby absorbing longitudinal displacement of the piping. This sealing device is based on the premise that the piping extends straight through the wall of the building, and therefore cannot be used when there is not enough space outside the building to allow the piping to extend as is. Therefore, there is room for improvement in absorbing longitudinal displacement of the piping in a compact space.

JP 2014-92214 A

The object of the present invention is to provide a compact seal structure that can absorb longitudinal displacement of the pipe body while ensuring a seal at the connection between the pipe body and the mounting part that are connected via a joint device.

In order to achieve the above object, the seal structure of the present invention has a joint device which connects a pipe to an attachment portion, one end of the pipe is connected to the joint device by communicating the flow paths of the pipe and the joint device, and an insertion portion of the joint device is inserted into the attachment portion by communicating the flow paths of the joint device and the attachment portion, and is connected to the attachment portion by connecting the flow paths of the joint device and the attachment portion. The seal structure has a cylindrical sleeve and a pair of cylindrical seal bodies formed of an elastic material, the sleeve and each of the seal bodies are arranged on the same cylindrical axis, the insertion portion penetrates each of the seal bodies and the sleeve with the sleeve sandwiched between the respective seal bodies, a gap is formed between an inner peripheral surface of the sleeve and an outer peripheral surface of the insertion portion, the one end is fixed to a fitting portion formed by penetrating a peripheral wall of the sleeve, and each of the seal bodies has a respective one of the seal bodies. a plurality of annular hard bodies coaxial with a pipe body are embedded at intervals in the axial direction of the pipe body and are not exposed to the outside of each of the seal bodies , the surface of each of the seal bodies is made of the elastic material, and when the insertion portion is inserted into the mounting portion and connected, each of the seal bodies sandwiching the sleeve therebetween is compressed in the axial direction of the pipe body between the end face of the mounting portion and the flange portion of the joint device, and the flow paths of the pipe body, the joint device, and the mounting portion are communicated via the sleeve, and the sleeve fixed to one end of the pipe body and the joint device are not in direct contact with each other but the sealing material is interposed between them, and when the pipe body is displaced in the longitudinal direction of the pipe body, the annular elastic portion made of the elastic material present between the respective hard annular bodies in each of the seal bodies is configured to shear deform .

According to the present invention, each of the seal bodies sandwiching the sleeve is compressed in the axial direction between the end face of the mounting part and the flange part of the joint device, so that the connection part of the mounting part, the joint device, and the sleeve can be secured with the seal bodies to provide sufficient sealing. When the tube body is displaced in the longitudinal direction, the elastic material (annular elastic part) present between the annular hard bodies embedded in each of the seal bodies undergoes shear deformation, and the seal body is elastically deformed, so that the displacement can be absorbed. Furthermore, by using the joint device, the extension direction of the tube body is generally perpendicular to the flow path of the mounting part. Therefore, this seal structure can be used even if there is not enough space outside the mounting part in the extension direction of the flow path of the mounting part.

1 is an explanatory diagram illustrating a seal structure of the present invention in a vertical cross-sectional view. 2 is an explanatory diagram illustrating the seal structure of FIG. 1 in a plan view. 2 is a perspective view illustrating half of the seal body of FIG. 1 ; FIG. 2 is a cross-sectional view taken along line AA of FIG. 1. 5A and 5B show the sleeve of FIG. 1 alone, with FIG. 5A being a longitudinal sectional view and FIG. 5B being a side view. 6A is a longitudinal sectional view of the joint device of FIG. 1, and FIG. 6B is a sectional view taken along line BB of FIG. 6A. 2 is an explanatory diagram illustrating a state in which a fluid flows through each of the flow paths in FIG. 1 . FIG. 8 is an explanatory diagram illustrating a state in which the seal body in FIG. 7 is elastically deformed. FIG.

The sealing structure of the present invention will be described below based on the embodiment shown in the figures.

1 and 2, the embodiment of the seal structure has a joint device 6 that connects a pipe body 4 to a mounting portion 7 of various devices such as a hydraulic machine. One end of the pipe body 4 is connected to the joint device 6 by communicating the flow paths 4a, 6a between the pipe body 4 and the joint device 6, and the insertion portion 6A of the joint device 6 is inserted into the mounting portion 7 by communicating the flow paths 6a, 7a between the joint device 6 and the mounting portion 7. In this way, the respective flow paths 4a, 6a, 7a are in communication. The fluid F flowing through the flow paths 4a, 6a, 7a may be liquid (various oils, chemicals, water, etc.) or gas (various gases, air, etc.).

This seal structure has a joint device 6, a cylindrical sleeve 5, and a pair of cylindrical seal bodies 1 formed from an elastic material. The sleeve 5 and each seal body 1 are arranged on the same cylindrical axis, with the sleeve 5 sandwiched between each seal body 1. The insertion portion 6A of the joint device 6 passes through each seal body 1 and sleeve 5.

The tube 4 may be a pipe with poor flexibility made of metal, hard resin with very high bending rigidity, or a composite of these materials, or a rubber hose with excellent flexibility. The dashed line CL in the figure indicates the axis extending through the center of the cross section of the tube 4. The extension direction of the dashed line CL is the longitudinal direction (axial direction) of the tube 4. The dashed line Cx indicates the axis of the flow path 7a. This dashed line Cx also indicates the cylinder axis (axial center) extending through the center of the cross section of the cylindrical seal body 1, the cylindrical sleeve 5, and the cylindrical insertion part 6A. The extension direction of the dashed line Cx is the cylinder axis (axial direction) of the seal body 1, the sleeve 5, and the insertion part 6A.

The seal body 1 is made of an elastic material. Various known vulcanized rubbers and elastomers can be used as this elastic material. In this embodiment, a protrusion 3a that protrudes radially inward is formed on the inner circumferential surface of the seal body 1. That is, the cylindrical seal body 1 has a protrusion 3a made of an elastic material on its inner circumferential surface. This protrusion 3a may be a continuous ring shape in the circumferential direction, or may be arranged intermittently in the circumferential direction. This protrusion 3a can be provided as needed.

As shown in Figures 1, 3, and 4, multiple annular hard bodies 2 are embedded in the seal body 1 at a predetermined interval g in the axial direction of the cylinder, and are coaxial with the seal body 1. Each annular hard body 2 is embedded in the seal body 1 without being exposed to the outside of the seal body 1. Therefore, the surface of the seal body 1 is made of an elastic material. The annular hard bodies 2 are harder and have higher rigidity (modulus) than the elastic material forming the seal body 1, and are made of various metals, hard resins, etc. In this embodiment, all the annular hard bodies 2 are simple circular ring bodies and have the same thickness (wall thickness).

In this embodiment, the number of annular hard bodies 2 is four, but the number can be set appropriately within the range of, for example, 3 to 10. The thickness (wall thickness) of the annular hard bodies 2 is, for example, about 0.1 mm to 1.0 mm. The predetermined gap g, which is the distance between adjacent annular hard bodies 2 in the axial direction, is, for example, 0.3 mm to 1.0 mm. Basically, the predetermined gap g is set to the same size at all positions, but the size of the predetermined gap g can also be made different depending on the position.

Between adjacent annular hard bodies 2 in the axial direction is a cylindrical annular elastic portion 3 made of the elastic material that forms the seal body 1. In other words, the annular hard bodies 2 and the annular elastic portions 3 are arranged alternately in the axial direction of the seal body 1. The thickness (wall thickness) of the annular elastic portion 3 is the size of a predetermined interval g. The pair of seal bodies 1 can have the same specifications or different specifications.

To manufacture this seal body 1, for example, a member corresponding to the seal body 1 is molded from unvulcanized rubber, and a molded body is formed with each annular hard body 2 embedded in this member. This molded body is then vulcanized by a known method. By vulcanizing the unvulcanized rubber, it becomes vulcanized rubber, which is an elastic material, and each annular hard body 2 is integrated with the elastic material (annular elastic portion 3) by vulcanization adhesion, thereby manufacturing the seal body 1.

The sleeve 5 is made of various metals, hard resins, and the like. As shown in Figs. 1 and 5, a cavity is formed inside the sleeve 5, penetrating in the axial direction, and this cavity functions as a flow path 5a. A fitting portion 5b is formed at one location on the peripheral wall of the sleeve 5, extending in the radial direction and penetrating the peripheral wall. More specifically, a through hole is formed on the bottom surface of the fitting portion 5b of the circular recess, which communicates with the cavity (flow path 5a) inside the sleeve 5. One end of the tube 4 is inserted and fixed into the fitting portion 5b (solidly integrated in an airtight or watertight manner).

As illustrated in Figs. 1 and 6, the joint device 6 has a cylindrical insertion portion 6A extending in the axial direction Cx, and a flange portion 6b that is arranged at one end of the insertion portion 6A and has a larger diameter. Inside the insertion portion 6A, a flow path 6a is formed that extends in the axial direction Cx to a position halfway through the joint device 6. In addition, a flow path 6a is formed that extends through the insertion portion 6A in the axial direction CL (a direction perpendicular to the axial direction Cx). Therefore, in the insertion portion 6A, the flow paths 6a intersect at right angles. The insertion portion 6A side of the flange portion 6b forms an end face that is perpendicular to the insertion portion 6A.

In this embodiment, the joint device 6 is a metal joint fitting, but it is not limited to this and can be made of, for example, hard resin. The joint device 6 is fixed to the flow path 7a of the attachment part 7 by screwing.

In this seal structure, as shown in FIG. 1, the sleeve 5 and each seal body 1 are arranged on the same cylinder axis, with the sleeve 5 sandwiched between each seal body 1. The insertion portion 6A penetrates each seal body 1 and sleeve 5. When the insertion portion 6A is inserted into and connected to the flow path 7a of the mounting portion 7, each seal body 1 sandwiching the sleeve 5 is compressed in the cylinder axis direction (axial direction Cx in FIG. 1) between the end face 7b of the mounting portion 7 and the end face of the flange portion 6b.

In more detail, in each compressed seal body 1, the annular elastic portion 3 is compressed in the axial direction, and one seal body 1 adheres closely to the end face 7b of the mounting portion 7 and one side of the sleeve 5. The other seal body 1 adheres closely to the end face of the flange portion 6b and the other side of the sleeve 5. The inner circumferential surface (protruding portion 3a) of each seal body 1 adheres closely to the outer circumferential surface of the insertion portion 6a. A gap (filling space 6c) is formed between the inner circumferential surface of the sleeve 5 and the outer circumferential surface of the insertion portion 6A, and the sleeve 5 and joint 6 do not directly abut.

The respective seal bodies 1 are in airtight or watertight contact with the mounting portion 7, the joint device 6, and the sleeve 5, so that sufficient sealing (airtightness or watertightness) can be ensured by the respective seal bodies 1 at the connection portions of the mounting portion 7, the joint device 6, and the sleeve 5. In this state, the respective flow paths 4a, 6a, and 7a are in communication via the sleeve 5 (flow path 5a).

The seal body 1 has a layered structure in which the annular hard body 2 and the annular elastic portion 3 are alternately arranged in the axial direction of the cylinder. Therefore, compared to when the annular hard body 2 is not embedded, the seal body 1 can be pressed more strongly against the end face 7b of the mounting portion 7, the end face of the flange portion 6b, and both sides of the sleeve 5 to make firm contact, which is advantageous for improving the sealing performance at the connection portion.

In this embodiment, the protrusion 3a is formed on the seal body 1, so that a filling space 6c is formed between the inner peripheral surface of the seal body 1 and the outer peripheral surface of the insertion portion 6A. This filling space 6c is connected to the flow paths 5a and 6a, so all of the flow paths 4a, 5a, 6a, and 7a are connected to the filling space 6c.

As shown in FIG. 7, in this seal structure, fluid F flows through each of the flow paths 4a, 5a, 6a, and 7a, and the filling space 6c is filled with fluid F. Therefore, in the radial direction, the inner circumferential surface of the seal body 1 is pressed by the pressure of the fluid F, and the outer circumferential surface is pressed by the external air pressure, creating a balance.

As shown in FIG. 8, depending on the site of use, an external force may act on the tube 4, pulling it in the longitudinal direction (axial direction). When such an external force acts, an excessive load is placed on the tube 4, and the tube 4 becomes more likely to come loose, which is disadvantageous in maintaining the connection between the tube 4 and the joint device 6. However, in this seal structure, when such an external force acts on the tube 4, the sleeve 5 is pulled along with the tube 4, and in each seal body 1, each annular elastic portion 3 is slightly shear deformed in the radial direction. The shear deformation of each annular elastic portion 3 accumulates, and each seal body 1 is elastically deformed, absorbing the longitudinal displacement of the tube 4.

As a result, the risk of excessive load being applied to the tube body 4 can be reduced. In addition, at the connection portion of the mounting portion 7, the joint device 6, and the sleeve 5, the connection between the tube body 4 and the mounting portion 7 via the joint device 6 can be maintained while ensuring sufficient sealing by the respective seal bodies 1. In cases where a metal pipe should be used as the tube body 4, there is no longer a need to change to a rubber hose to absorb the displacement of the tube body 4, which has the advantage of making it easier to use a metal pipe.

In this embodiment, the filling space 6c is filled with the fluid F. Accordingly, as described above, the inner peripheral surface of the seal body 1 is pressed toward the outer peripheral surface in the radial direction, and the outer peripheral surface is pressed toward the inner peripheral surface, so that the pressure is balanced in both radial directions. In a seal structure without the filling space 6c, the seal body 1 is simply pressed toward the inner peripheral surface in the radial direction by the external air pressure acting on the outer peripheral surface. Therefore, the specification with the filling space 6c makes it easier to elastically deform the seal body 1 in the radial direction compared to the specification without the filling space 6c. Therefore, it is advantageous for the seal body 1 to absorb the displacement of the tube body 4 pulled in the longitudinal direction.

The greater the number of annular elastic parts 3, the greater the amount of elastic deformation of the seal body 1. Therefore, if the longitudinal displacement of the tube body 4 is large, the number of annular elastic parts 3 (in other words, the number of annular hard bodies 2) should be increased. In other words, if the longitudinal displacement of the tube body 4 is large, it is advisable to use a seal body 1 with a large number of annular elastic parts 3 (annular hard bodies 2).

Even if the fluid pressure of the fluid F becomes high, each annular elastic portion 3 is sandwiched between the annular hard bodies 2, so the deformation is small, which is advantageous in avoiding the problem of each annular elastic portion 3 being damaged. Therefore, the seal body 1 can fully withstand high internal pressure. The smaller the predetermined distance g (thickness of the annular elastic portion 3) between the annular hard bodies 2, the less likely the annular elastic portion 3 is to shear. Therefore, making the predetermined distance g small is advantageous in suppressing damage to the annular elastic portion 3 caused by the fluid pressure of the fluid F. In other words, when the fluid pressure of the fluid F is very high, it is recommended to use a seal body 1 with a small predetermined distance g to prevent damage to the annular elastic portion 3.

By using this joint device 6, the extension direction of the tube body 4 is roughly perpendicular to the flow path 7a of the mounting part 7. Therefore, this seal structure can be used even if there is not enough space outside the mounting part 7 in the extension direction of the flow path 7a. As a result, it is advantageous to make the seal structure compact, and the longitudinal displacement of the tube body 4 can be absorbed in a compact space.

If each annular hard body 2 is made of metal, it is advantageous for the seal body 1 to be more firmly attached to the end face 7b of the mounting portion 7 and the side face of the sleeve 5, and to the end face of the flange portion 6b and the side face of the sleeve 5. If each annular hard body 2 is made of resin, it is possible to prevent the inconvenience of each annular hard body 2 corroding and deteriorating, and it is also advantageous for reducing the weight of the seal structure.

The elastic material forming the seal body 1 can be of the same specification (type) throughout the seal body 1. That is, the seal body 1 may be formed of one specification (one type) of elastic material, but the surface of the seal body 1 that comes into contact with the fluid F should be formed of an elastic material that has excellent resistance to the fluid F. Also, the surface of the seal body 1 that comes into contact with the outside air should be formed of an elastic material that has excellent resistance to the outside air. Therefore, in the seal body 1, the specification (type) of the elastic material can be different between the surface that comes into contact with the fluid F and other parts, and the specification (type) of the elastic material can be different between the surface that comes into contact with the outside air and other parts.

In this seal structure, the sleeve 5 fixed to the tube 4 and the joint device 6 do not come into direct contact with each other, but rather the seal body 1 (elastic material) is interposed between them. Therefore, vibrations transmitted between the tube 4 and the mounting part 7 are damped by the seal body 1. When the tube 4 is made of metal, vibrations in the tube 4 can be problematic, but this seal structure is useful for solving such problems.

Reference Signs List 1: seal body 2: annular hard body 3: annular elastic portion 3a: protrusion 4: pipe body 4a: flow passage 5: sleeve 5a: flow passage 5b: fitting portion 6: joint 6a: flow passage 6b: flange portion 6c: filling space 7: attachment portion 7a: flow passage 7b: end surface F: fluid

Claims (4)

A seal structure having a joint device for connecting a pipe body to an attachment portion, one end of the pipe body being connected to the joint device by communicating flow paths between the pipe body and the joint device, and an insertion portion of the joint device being inserted into and connected to the attachment portion by communicating flow paths between the joint device and the attachment portion,
a cylindrical sleeve and a pair of cylindrical seal bodies formed of an elastic material, the sleeve and each of the seal bodies are arranged on the same cylindrical axis, the insertion portion penetrates each of the seal bodies and the sleeve with the sleeve sandwiched between the seal bodies, a gap is formed between the inner peripheral surface of the sleeve and the outer peripheral surface of the insertion portion, and the one end is fixed to a fitting portion formed by penetrating a peripheral wall of the sleeve,
a plurality of annular hard bodies are embedded in each of the seal bodies, coaxially with each of the seal bodies, at intervals in a cylindrical axial direction , without being exposed to the outside of each of the seal bodies , and a surface of each of the seal bodies is made of the elastic material;
When the insertion portion is inserted into the mounting portion and connected, each of the seal bodies sandwiching the sleeve therebetween is compressed in the tubular axial direction between the end face of the mounting portion and the flange portion of the joint device, and the flow paths of the pipe body, the joint device, and the mounting portion are connected via the sleeve, and the sleeve fixed to one end of the pipe body and the joint device are not in direct contact with each other but each of the seal materials is interposed between them, and when the pipe body is displaced in its longitudinal direction, in each of the seal bodies, the annular elastic portion made of the elastic material present between each of the hard annular bodies is configured to shear deform . The seal structure described in claim 1, wherein a protrusion made of the elastic material protruding toward the outer peripheral surface of the insertion portion is formed on the inner peripheral surface of each of the seal bodies, and a filling space is formed between the inner peripheral surface and the outer peripheral surface, which is connected to each of the flow paths and is filled with fluid flowing through each of the flow paths by the protrusion abutting against the outer peripheral surface. The seal structure according to claim 1 or 2, wherein each of the annular hard bodies is made of metal. The seal structure according to claim 1 or 2, wherein each of the annular hard bodies is made of resin.

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