JP5360569B2 - Packing - Google Patents

Description

  The present invention is accommodated in a groove on the peripheral surface of a partition member such as a piston that slides in the axial direction in a cylindrical housing such as a cylinder tube of a fluid pressure cylinder, and seals between the inner surface of the cylindrical housing. It is related to packing.

  In a partition member such as a piston that slides in the axial direction in a cylindrical housing such as a cylinder tube of a fluid pressure cylinder, the gap between the inner surface of the cylindrical housing is sealed by a packing accommodated in a groove on the peripheral surface. However, aside from the rubber elastic packing (O-ring or the like) that normally bears the sealing function, a part of the packing is caused to be in the cylinder tube inner surface by a load in the direction perpendicular to the axial direction acting on the partition member. A wear ring that is pressed against the surface and is prevented from being extremely crushed is fitted in parallel to the packing. This wear ring is formed in a ring shape partially having a cut for fitting to a partition member such as a piston, etc. by a synthetic resin that is harder than the above packing and has excellent slidability. It has a function to hold the axis so that it does not deviate from the axis of the cylindrical housing.

  As an example of an apparatus provided with the above-described packing (seal ring) and the above-mentioned wear ring (back-up ring) on a piston that is inserted into a cylinder, Patent Document 1 discloses a cross section made of a rubber material in an annular groove on the outer peripheral surface of the piston. A circular seal ring and a backup ring that is harder than the seal ring and has a rectangular cross section are fitted in parallel.

  However, in the conventionally known ones including those described in Patent Document 1, since the packing itself has soft elasticity suitable for sealing, there is no space between the cylindrical housing and the partition member. In addition, it is necessary to interpose a wear ring (a backup ring) for holding the axis of the partition member on the axis of the cylindrical housing. Since it is necessary to fit in the mounting groove on the outer periphery, there is a problem that the assembly process becomes complicated.

Japanese Patent Laid-Open No. 9-72310

The technical problem of the present invention is that the wear ring is improved by improving the packing that is accommodated in the groove on the peripheral surface of the partition member that slides in the axial direction in the cylindrical housing and seals between the cylindrical housing. It is to eliminate the need to use the structure, simplify the structure of the partition member, and reduce the cost.
Another technical object of the present invention is to provide a packing made of a single rubber elastic material having the above-described wear ring function.

In order to solve the above-described problems, according to the present invention, there is provided a packing that is accommodated in a groove on a peripheral surface of a partition member that slides in the axial direction in a cylindrical housing and seals between the cylindrical housing. In addition, a seal projection that elastically contacts the cylindrical housing is provided on the outer peripheral surface of the packing body accommodated in the groove, and is positioned on both sides of the seal projection so as to be orthogonal to the axial direction acting on the partition member. A receiving surface that abuts against the cylindrical housing and prevents the cylindrical housing and the partition member from contacting each other when the sealing protrusion is crushed by a load in a direction in which the rubber is elastic. The packing is characterized in that the packing has a cross-sectional area larger than that of the groove provided on the peripheral surface of the partition member, and a part of the packing protrudes outside from the groove. Will be provided

In a preferred embodiment of the packing according to the present invention, between the seal projection in the packing body and the receiving surface on both sides or one side thereof, it serves as a grease reservoir, and the relief portion during crushing of the seal projection A concave groove is formed.
The receiving surface can be provided with a plurality of circumferential narrow grooves serving as grease reservoirs.

Moreover, in preferable embodiment of this invention, the inner peripheral seal convex part which contacts the bottom face elastically is provided in the inner peripheral face of the packing main body which contact | connects the bottom face of the groove | channel of the peripheral surface of a partition member.
The inner peripheral seal convex portion is provided in the same axial position as the partition member with respect to the seal protrusion, and is positioned on both sides of the inner peripheral protrusion and on both sides of the seal protrusion. in correspondence with the surface, it has to have desired provided with a contact surface in contact with the bottom surface of the groove of the partition member periphery when the inner peripheral seal projection portion by a load in the direction perpendicular to the axial direction is collapsed.

  In the packing having the above-described configuration, the seal projection is elastic with respect to the entire inner circumference of the cylindrical housing when there is no load acting on the partition member in the direction orthogonal to the axial direction (hereinafter referred to as lateral load). The two sides of the partition member are kept in a sealed state. On the other hand, when the lateral load is applied, the seal projection on the side receiving the lateral load is compressed, and the reaction force causes the partition The member is pushed back against the lateral load, but when the lateral load is further increased and the sealing projection is crushed, the receiving surfaces provided on both sides of the sealing projection abut against the inner surface of the cylindrical housing. In contact therewith, the cylindrical housing and the partition member are prevented from coming into contact with each other.

The packing is formed on the inner peripheral surface thereof with a contact surface corresponding to the receiving surface so as to come into contact with the bottom surface of the groove when a lateral load is applied. Since it is possible to provide a means for suppressing the diameter reduction of the receiving surface such as setting it to be larger than the cross-sectional area of the groove of the surface, the means prevents the cylindrical housing and the partition member from contacting each other, and consequently The receiving surface can exhibit the same function as the conventional wear ring.
In addition, since the packing is formed integrally with the packing main body by the rubber elastic material so as to exhibit the functions of the sealing protrusion and the wear ring, not only the structure of the partition member but also its assembly process is extremely simple. It becomes.

  According to the packing of the present invention described in detail above, the structure of the packing accommodated in the groove on the peripheral surface of the partition member sliding in the axial direction in the cylindrical housing is improved, and the wear ring function is also provided. Since the packing made of a single rubber elastic material is used, it is not necessary to use a wear ring, and the configuration of the partition member can be simplified and the cost can be reduced.

It is sectional drawing which shows the use condition of 1st Example of the packing which concerns on this invention. It is sectional drawing which shows the state of the non-insertion insertion to the cylindrical housing of the packing of the said 1st Example. It is a half sectional view showing the state where packing of the above-mentioned 1st example was attached to the piston of a fluid pressure cylinder. It is sectional drawing of 2nd Example of the packing which concerns on this invention. It is sectional drawing of 3rd Example of the packing which concerns on this invention. It is sectional drawing of 4th Example of the packing which concerns on this invention. It is sectional drawing of 5th Example of the packing which concerns on this invention.

  1 to 3 show a first embodiment of the packing according to the present invention, and FIG. 1 shows a partition in which the packing 1A of the first embodiment slides in the cylindrical housing 11 in the axial direction thereof. 2 shows a state in which the cylindrical housing 11 is sealed in a state where it is accommodated in the groove 13 on the peripheral surface of the member 12 and receives no lateral load, and FIG. Although it is accommodated in the groove 13 of the surface, the partition member 12 is not inserted into the cylindrical housing 11, and the position of the inner surface of the cylindrical housing 11 is indicated by a chain line a. Further, in FIG. 3, the cylindrical housing 11 is a cylinder tube 21 of the fluid pressure cylinder 20, and the groove 23 on the peripheral surface of the piston 22 as the partition member 12 that slides in the cylinder tube 21 in the axial direction thereof. A state in which the packing 1A is mounted is shown.

3 as an example of an apparatus using the packing, the piston rod 24 connected to the piston 22 is passed through the seal 26 in the rod cover 25 at the end of the cylinder tube 21 to the outside. Derived and driven in the axial direction by compressed air supplied and discharged from the pressure air source to the pressure chambers 28a and 28b on both sides of the piston 22 through a pair of supply and discharge ports 27a and 27b.
The lateral load usually acts on the piston 22 as a force perpendicular to the axis based on a force acting in a direction perpendicular to the axis of the piston rod 24 by a member connected to the tip of the piston rod 24. Is.

  As can be seen from FIGS. 1 and 2, the packing 1 </ b> A of the first embodiment is formed in a center of the outer peripheral surface of the packing body 2 that is formed of a rubber elastic material and accommodated in the groove 13. The seal projections 3 that elastically contact the inner surface of the cylindrical housing 11 are provided, and the seal projections 3 are positioned on both sides of the cylindrical housing 11 so that the seal projections 3 are crushed by the lateral load. And a pair of receiving surfaces 4 for preventing the cylindrical housing 11 and the partition member 12 from contacting each other, and further, between the sealing protrusion 3 and the receiving surfaces 4 on both sides thereof, A pair of concave grooves 5 are also provided which also serve as grease reservoirs and form relief portions during crushing of the protrusions 3 for sealing.

  Further, the inner peripheral surface of the packing body 2 that is in contact with the bottom surface of the groove 13 on the peripheral surface of the partition member 12 elastically contacts the bottom surface and stably seals between the bottom surface and the packing body 2. An inner peripheral seal projection 6 is provided. The inner peripheral seal projection 6 is desirably provided in the same axial position as the partition member 12 with respect to the seal projection 3, and the seal projection 3 is provided on both sides of the inner seal projection 6. Corresponding to the receiving surfaces 4 located on both sides, the contact surface 7 that abuts against the bottom surface of the groove 13 of the partition member 12 when the inner peripheral seal projection 6 is crushed by the lateral load is provided. These parts are integrally formed with the packing body 2 by a rubber elastic material.

  The packing 1A of the first embodiment having the above-described configuration is inserted into the cylindrical housing 11 from the state shown in FIG. 2 in the state shown in FIG. 1 in which the sealing projection 3 is pressed by the inner surface of the cylindrical housing 11. In a state where no lateral load is applied to the partition member 12, the sealing projection 3 is elastically and evenly abutted against the entire inner circumference of the cylindrical housing 11, so that the space between both side spaces of the partition member 12 is between. When the lateral load is applied, the sealing projection 3 on the side receiving the lateral load is compressed. However, the lateral load increases and the sealing projection 3 is crushed. In this case, the receiving surfaces 4 provided on both sides of the seal projection 3 are brought into contact with the inner surface of the cylindrical housing 11 to prevent damage caused by contact between the cylindrical housing 11 and the partition member 12. It will be.

The packing 1A has, on its inner peripheral surface side, a contact surface 7 that contacts the bottom surface of the groove 13 when a lateral load is applied, corresponding to the receiving surface 4, or has a cross-sectional area of the packing. Since it is possible to provide a means for suppressing the diameter reduction of the receiving surface 4 such as setting it to be larger than the cross-sectional area of the groove 13, it is possible to prevent the cylindrical housing 11 and the partition member 12 from contacting each other by the lateral load. As a result, the receiving surface 4 can exhibit the same function as the conventional wear ring.
In addition, since the packing 1A is integrally formed with the seal projection 2 and the receiving surface 4 that functions as a wear ring on the packing body 2 by a single rubber elastic material, only the configuration of the partition member 12 is provided. In addition, the assembly process is greatly simplified.

  A concave groove 5 is provided between the sealing projection 3 in the packing body 2 and the receiving surfaces 4 on both sides thereof, and the concave groove 5 also functions as a grease reservoir as described later. The sealing projection 3 is pressed against the inner surface of the cylindrical housing 11, and the top surface is crushed as shown in FIG. 1, or the receiving surfaces 4 on both sides of the sealing projection 3 are formed on the cylindrical housing 11. When the seal projection 3 is crushed to the extent that it is in contact with the inner surface, the seal projection 3 also functions as a relief for flattening and spreading in the width direction, and the seal projection 3 itself is excessive. It suppresses being damaged by receiving the crushing force.

FIG. 4 shows a second embodiment of the packing according to the present invention, and in this packing 1B, the sealing protrusion 3 in the packing 1A of the first embodiment is provided at the center of the outer peripheral surface of the packing body 2. On the other hand, the sealing projection 3 is provided at a position offset to one side of the outer peripheral surface. The packing 1B of the second embodiment can be effectively used in, for example, a piston of a single-action cylinder in which pressures acting on both sides of the partition member 12 are not equal.
The other configurations and operations of the packing 1B of the second embodiment are substantially the same as those of the packing 1A of the first embodiment. Is omitted.

  The packing 1C of the third embodiment shown in FIG. 5 is such that the sealing protrusions 3 of the packings 1A and 1B in the first and second embodiments protrude from the outer peripheral surface of the packing body 2 into a gentle chevron. In contrast, the sealing function part 3a at the center of the sealing projection 3 is formed in a narrow mountain shape, and this sealing function part 3a is sealed on the inner surface of the cylindrical housing 11 indicated by a chain line b. When the contact is made in a state, thereby reducing the sliding resistance between the sealing function portion 3a and the inner surface of the cylindrical housing 11, however, the entire sealing protrusion 3 is formed into a narrow chevron. Because the fluid pressure and sliding resistance acting on the sealing projection 3 tend to collapse, the sealing function portion 3a is provided on the base portion 3b for reducing the height of itself. . The small protrusion provided on the base 3b is not necessarily provided, but the inside thereof can also function as a grease reservoir close to the seal function part 3a.

FIG. 6 shows a fourth embodiment of the packing according to the present invention. In the packing 1D according to the fourth embodiment, the seal protrusion 3 in the packing body 2 is compared with the packing 1A according to the first embodiment. The difference is that no concave groove 5 is provided between the receiving surfaces 4 on both sides.
However, when the seal 1D shown in FIG. 6 is inserted into the cylindrical housing 11 and the sealing projection 3 is pressed by the inner surface of the cylindrical housing 11, the sealing projection 3 is attached to the packing body 2. 1 is generally formed on both sides of the sealing projection 3 so that the groove 5 is formed as shown in FIG. It is not necessary to provide the groove 5 as in the embodiment, and there is no difference from the case of the first embodiment even if it is configured as in the fourth embodiment of FIG.

  Further, the concave groove 5 in the first embodiment or the like scrapes the grease adhering to the inner surface when the sealing projection 3 originally slides in contact with the inner surface of the cylindrical housing 11. It acts as a grease reservoir that flows down into the concave groove 5 and accumulates it, reducing the sliding resistance of the sealing projection 3, and the sealing projection 3 is crushed by a lateral load, so that the receiving surface 4 is a cylindrical housing. 11, which contributes to a reduction in sliding resistance when pressed against the inner surface, but when such a grease reservoir is not required, the sealing protrusion 3 is pushed into the upper surface of the packing body 2. Apart from whether or not the same groove as the groove 5 is formed on both sides, it is not necessary to provide a groove corresponding to the groove 5 as in the fourth embodiment. The concave groove 5 may be provided only on one side of the sealing projection 3.

  Further, FIG. 7 shows a fifth embodiment of the packing according to the present invention. In the packing 1E of the fifth embodiment, the receiving surface 4 is provided with a plurality of circumferential narrow grooves 5a serving as grease reservoirs, The sliding resistance is reduced when the receiving surface 4 comes into contact with the inner surface of the cylindrical housing 11. However, not only the narrow groove 5a but also various means for reducing sliding resistance when contacting the inner surface of the cylindrical housing 11 can be added to the receiving surface 4.

  In addition, since the other structure and operation | movement except the point mentioned above about the said 3rd-5th Example are substantially the same as the case of the packing 1A of 1st Example, the same code | symbol is attached to the same part or an equivalent part. A description thereof will be omitted.

1A to 1E Packing 2 Packing body 3 Sealing protrusion 4 Receiving surface 11 Tubular housing 12 Partition member 13 Groove

Claims (5)

A packing that is accommodated in a groove on a peripheral surface of a partition member that slides in the axial direction in the cylindrical housing and seals between the cylindrical housing,
A direction perpendicular to the axial direction acting on the partitioning member is provided on the outer peripheral surface of the packing main body accommodated in the groove, and is provided with sealing protrusions that elastically contact the cylindrical housing, and located on both sides thereof. A receiving surface that abuts against the cylindrical housing and prevents the cylindrical housing and the partition member from coming into contact with each other when the sealing projection is crushed by a load of Forming ,
The packing cross-sectional area is larger than the cross-sectional area of the groove provided on the peripheral surface of the partition member, and a part of the packing protrudes outside from the groove.
Packing characterized by that. Between the seal projection in the packing body and the receiving surface on both sides or one side thereof, a groove is provided that also serves as a grease reservoir and forms a relief portion during crushing of the seal projection.
The packing according to claim 1. A plurality of circumferential narrow grooves serving as grease reservoirs are provided on the receiving surface.
The packing according to claim 1 or 2, wherein Provided on the inner peripheral surface of the packing body that is in contact with the bottom surface of the groove on the peripheral surface of the partition member is an inner peripheral seal convex portion that elastically contacts the bottom surface.
The packing according to any one of claims 1 to 3. The inner peripheral seal convex portion is provided in the same axial position of the partition member with respect to the seal projection, and the receiving surface is located on both sides of the inner seal convex portion on both sides of the seal projection. Correspondingly, the contact surface that contacts the bottom surface of the groove of the partition member peripheral surface when the inner peripheral seal convex portion is crushed by a load in a direction orthogonal to the axial direction,
The packing according to claim 4.

Images