JP4829651B2 - Sealing material - Google Patents

Description

  The present invention relates to a seal used for a transport container for transporting parts and the like that are processed and manufactured in a clean environment from a manufacturing base to another manufacturing base and a transport container for transporting between processes. Concerning materials, in particular, transport containers that are used to take silicon wafers, etc. that do not like contamination in the semiconductor manufacturing process, when taking them out of the clean room, and transport containers that are used to prevent contamination when moving between processes in the clean room. It is related with the sealing material used in.

  In semiconductor manufacturing, extremely high processing accuracy has been required due to the progress of circuit miniaturization, and not only each manufacturing process but also silicon wafers are placed from the trend of increasing the diameter of silicon wafers (300 mm). There is a need to improve the cleanliness of all environments. For example, with respect to a container used for transporting / transferring a silicon wafer having a larger diameter and more susceptible to contamination, it is necessary to maintain the inside of the container at a high degree of cleanliness. Therefore, a sealing material made of resin or rubber material is incorporated in the transport / transfer container.

  As a general rubber seal material, there are an O-ring having various cross-sectional shapes designed in accordance with a substantially circular or rectangular cross-section or the shape of a mating member. When a load is applied and they are crushed, a sealing function is generated by an elastic force as a reaction force. However, transport and transport container bodies used in semiconductor manufacturing are made of synthetic resin that does not have high material strength (rigidity). When such a seal member is used, the reaction force required for sealing is reduced. In order to make it generate | occur | produce, a big load must be applied, and it will cause a deflection | deviation in the container itself. As a result, a uniform crushing amount cannot be given over the entire circumference of the sealing material, and the reaction force generated in the sealing material varies, and in a region where the crushing amount is small, a seal failure occurs due to insufficient reaction force of the seal. There's a problem.

  Here, for example, a sealing material (sealing structure) described in JP-A-9-45759 has been proposed. That is, it is a seal structure in which a molded rubber or thermoplastic resin sealant is mounted in a sealant mounting groove and is combined with a mating member formed with a projection, and the container bends due to the projection of the mating member. It is intended to realize the sealing performance with a low load that is not allowed to occur. The problem with this seal structure is that the protrusion and the seal material are likely to stick due to excessive stress concentration, and the seal material is likely to drop out of the mounting groove when the container is opened. In addition, when the dimensional error of the container is large, the tightening allowance (crushing amount of the sealing material) may be insufficient, but a slight decrease in the crushing amount significantly reduces the reaction force of the sealing material, and tightening on all the sealing surfaces. There is a problem that a seal failure is likely to occur due to variation in cost.

Further, as shown in FIG. 6, a sealing material 50 having a lip shape in cross section has been proposed in order to exhibit sealing performance with a load that does not deflect the container. The sealing material 50 has sufficient sealing performance even at a low load due to the reaction force based on the bending of the lip portion 50B by bringing the tip of the lip portion 50B extending from the base portion 50A attached to the attachment groove 52 into contact with the mating member 54. Is possible. Further, since the lip portion 50B can be greatly bent as compared with the above-described normal sealing material such as a circular shape or a rectangular shape, the sealing material can tolerate a slight bending of the container and a variation in tightening due to a dimensional error. It was conceived as.
Japanese Patent Laid-Open No. 9-45759

  However, the relationship between the change in the deflection amount (compression amount) of the lip portion of this type of sealing material and the seal stress generated thereby is as shown in the graph in FIG. That is, this sealant has the property that the seal reaction force increases moderately when the deflection (compression ratio) is small, but the seal reaction force increases rapidly from a certain degree of deflection (compression ratio). is doing. The fact that the seal reaction force differs greatly before and after the inflection point of this graph makes it difficult to tolerate variations in tightness due to dimensional errors and processing accuracy of containers and seal materials, resulting in unstable sealing performance. There's a problem.

  In view of the above circumstances, an object of the present invention is to provide a sealing material that has a sealing property at a low load and can exhibit a stable sealing property even if the tightening allowance varies in the entire circumferential area of the sealing surface. And

The invention according to claim 1 is a base portion to be mounted in a mounting groove, a lip portion that is formed to extend obliquely from the base portion and is elastically deformable, and the mounting of the lip portion formed on the lip portion. A bent portion that changes an inclination angle with respect to the bottom surface of the groove , wherein the bent portion is in a state in which the seal material mounted in the mounting groove seals a gap with a counterpart member. A first projecting portion projecting to the mating member side, and a second projecting portion projecting to the opposite side of the projecting first projecting portion with respect to the mating member , the lip portion being the lip A first lip portion on the distal end side of the portion, and a second lip portion continuous with the base portion, and the gap between the first protrusion portion and the second protrusion portion is from the second lip portion to the first lip portion. In a direction away from the mating member toward the lip Characterized in that consists of out elastic portion.

According to a second aspect of the present invention , in the sealing material according to the first aspect, an inclination angle of the second lip portion with respect to a bottom surface of the mounting groove is an inclination angle of the first lip portion with respect to a bottom surface of the mounting groove. It is characterized by being relatively large.

According to a third aspect of the present invention, in the sealing material according to the first or second aspect , the bent portion generates a reaction force from the mating member acting on the lip portion by using the first lip portion and the second lip portion. It divides | segments between parts .

According to a fourth aspect of the present invention , in the sealing material according to any one of the first to third aspects, the sealing material mounted in the mounting groove seals a gap with the counterpart member. The first lip portion is in contact with the mating member, and the bent portion and the second lip portion are not in contact with the mating member.

According to a fifth aspect of the present invention , in the sealing material according to any one of the first to fourth aspects, the first lip portion is elastically deformed prior to the second lip portion by a reaction force from the mating member. The second lip portion starts elastic deformation after the first lip portion completes elastic deformation.

According to the present invention, while having a sealing property with a low load, a stable sealing property can be exhibited even if the tightening allowance varies in the entire circumferential area of the sealing surface.
Further, since the lip portion is formed with a bent portion that changes the inclination angle of the lip portion with respect to the bottom surface of the mounting groove, even when a reaction force acts on the lip portion from the mating member, it is abrupt like a conventional sealing material. Therefore, the seal reaction force does not increase, and the amount of bending of the lip portion and the seal reaction force are in a substantially proportional relationship. As a result, the tightening allowance changes with the dimensional error and processing accuracy of the transport container and seal material, and even if there is some variation in the compression amount of the seal material over the entire circumference of the seal surface, this is allowed by the elastic deformation of the lip part. And stable sealing performance can be exhibited. Compared to conventional O-rings with a circular or rectangular cross-section, sealing with a lip portion with a small contact area makes it possible to achieve sealing with a small tightening load. For example, automatic opening and closing work with an opener opening and closing device is a prerequisite. It becomes a suitable thing as a sealing material of the conveyance / conveyance container for semiconductor wafers used.
Further, in the region where the compression amount of the lip portion by the counterpart member is small, the compression amount is absorbed mainly by the bending of the first lip portion located on the tip portion side with the bent portion as a fulcrum, and a seal reaction force is generated. For this reason, in the initial compression region of the lip portion, the first lip portion that is shorter than the lip portion of the conventional sealing material by being divided by the bent portion causes a higher seal reaction than the lip portion of the conventional sealing material. Can generate power. Moreover, the time until the first lip portion becomes difficult to be elastically deformed is faster than that of the lip portion of the conventional sealing material. When a compressive force is further applied to the first lip portion from a state in which the first lip portion is difficult to be elastically deformed, the first lip portion tends to generate a high seal reaction force. 2 absorbed by the lip. As a result, it is possible to prevent a sudden increase in the seal reaction force of the seal material, and the seal reaction force generated by the seal material is moderate in relation to the amount of compression in the reaction force region required for sealing (sealing). (Relatively gentle proportional relationship of the slope).
Furthermore, by forming a plurality of bent portions in the lip portion, the inclination of the seal reaction force with respect to the compression amount (deflection amount) of the lip portion can be reduced, so this sealant is used in a relatively low reaction force region. It can be used as a low load sealing material.

  Next, the sealing material which concerns on 1st Embodiment of this invention is demonstrated with reference to drawings.

  As shown in FIGS. 1 and 2, the sealing material 10 of this embodiment includes a base portion 14 made of a rubber / elastomer material that is mounted in the mounting groove 12. The base portion 14 includes a base body 14A that presses one side wall 12A of the mounting groove 12 and a pressing portion 14B that is integrally formed with the base body 14A and presses the other side wall 12B of the mounting groove 12.

  Further, an elastically deformable lip portion 16 extending in an oblique direction is formed at the upper end portion of the base portion 14. The lip portion 16 is formed with a bent portion 18 for changing an inclination angle of the mounting groove 12 of the lip portion 16 with respect to the bottom surface 12C. Specifically, the lip portion 16 includes a first lip portion 16A extending from the bent portion 18 to the tip end portion of the lip portion 16, and a second lip portion 16B extending from the base portion 14 to the bent portion 18. As shown in FIG. 1, the inclination angle Y of the second lip portion 16B with respect to the bottom surface 12C of the mounting groove 12 is larger than the inclination angle X of the first lip portion 16A with respect to the bottom surface 12C of the mounting groove 12. Is set to

  Next, the effect | action of the sealing material 10 of this embodiment is demonstrated.

  As shown in FIGS. 1 and 2, the lip portion 16 is formed with a bent portion 18 that changes the inclination angle of the mounting groove 12 of the lip portion 16 with respect to the bottom surface 12 </ b> C. Even when the reaction force acts, the seal reaction force does not increase abruptly as in the case of the conventional sealing material, and the deflection amount of the lip portion 16 and the seal reaction force are in a substantially proportional relationship (see FIG. 3). As a result, the tightening margin changes with the dimensional error and processing accuracy of the transport container and the sealing material 10, and even if there is some variation in the compression amount of the sealing material 10 over the entire circumference of the sealing surface, the elastic deformation of the lip portion 16 causes This can be allowed and stable sealing performance can be exhibited.

  In addition, sealing with a lip portion 16 having a small contact area as compared with conventional O-rings having a circular or rectangular cross-section can achieve sealing with a small tightening load. For example, automatic opening / closing work by an opener opening / closing device is possible. This is suitable as a sealing material for a transport / container for a semiconductor wafer which is a premise.

  Specifically, in a region where the compression amount of the lip portion 16 by the counterpart member 20 is small, the compression amount is absorbed mainly by the bending of the first lip portion 16A located on the distal end side with the bent portion 18 as a fulcrum. Reaction force is generated. For this reason, in the initial compression region of the lip portion 16, the first lip portion 16 </ b> A that is shorter than the lip portion of the conventional sealing material by being divided by the bent portion 18, than the lip portion of the conventional sealing material. High seal reaction force can be generated.

  In addition, the time until the first lip portion 16A reaches a state where it is difficult to be elastically deformed is faster than the lip portion of the conventional sealing material. When the compression force is further applied from the mating member 20 to the first lip portion 16A from the state in which the first lip portion 16A is difficult to be elastically deformed, the first lip portion 16A attempts to generate a high sealing reaction force. The seal reaction force is absorbed by the second lip portion 16B. Thereby, the rapid increase of the seal reaction force of the seal material 10 can be prevented, and the seal reaction force generated by the seal material 10 is related to the compression amount in the reaction force region necessary for sealing (sealing). It can be moderate (relatively proportional proportionality of inclination).

  Next, the sealing material which concerns on 2nd Embodiment of this invention is demonstrated.

  As shown in FIG. 4, a plurality of bent portions 34 and 36 are formed in the lip portion 32 of the sealing material 30 of the present embodiment. Specifically, the lip portion 32 is formed with two first bent portions 34 and a second bent portion 36, respectively, and the first lip portion 32A extending from the second bent portion 36 to the tip end portion of the lip portion 32, The second lip portion 32B extends from the first bent portion 34 to the second bent portion 36, and the third lip portion 32C extends from the base portion 14 to the first bent portion 34.

  Next, the operation of the sealing material 30 according to the second embodiment of the present invention will be described.

  As shown in FIG. 4, by forming a plurality of bent portions 34 and 36 on the lip portion 32, the amount of compression of the lip portion 32 (compared to the conventional sealing material 50 and the sealing material 10 of the first embodiment ( Since the inclination of the seal reaction force with respect to the deflection amount can be reduced (see FIG. 5), the seal material 30 can be used as a low-load seal material used in a relatively low reaction force region.

It is sectional drawing of the sealing material of 1st Embodiment of this invention. It is sectional drawing which shows the state sealed with the sealing material of 1st Embodiment of this invention. It is the graph which showed the relationship between the sealing reaction force of the sealing material of 1st Embodiment of this invention, and the conventional sealing material, and a compression rate. It is sectional drawing of the sealing material of 2nd Embodiment of this invention. It is the graph which showed the relationship between the sealing reaction force of the sealing material of 2nd Embodiment of this invention, and the conventional sealing material, and a compression rate. It is sectional drawing of the conventional sealing material. It is the graph which showed the relationship between the seal reaction force of the conventional sealing material, and a compression rate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Sealing material 14 Base 16 Lip part 16A 1st lip part 16B 2nd lip part 18 Bending part 30 Sealing material 34 Bending part 36 Bending part
X Inclination angle of the 1st lip
Inclination angle of Y 2nd lip

Claims (5)

A base portion mounted in the mounting groove, a lip portion extending in an oblique direction from the base portion and elastically deformable, and an inclination angle of the lip portion formed on the lip portion with respect to a bottom surface of the mounting groove is changed. A sealing material having a bent portion ,
The bent portion includes a first projecting portion projecting toward the mating member in a state in which the seal member mounted in the mounting groove seals a gap with the mating member, and the first projecting portion based on the mating member. A second projecting portion projecting on the opposite side to the projecting portion projecting side ,
The lip portion includes a first lip portion on a distal end side of the lip portion, and a second lip portion continuous with the base portion ,
The space between the first projecting portion and the second projecting portion is constituted by an elastic portion extending from the second lip portion toward the first lip portion in a direction away from the counterpart member. Characteristic sealing material. The sealing material according to claim 1 , wherein an inclination angle of the second lip portion with respect to a bottom surface of the mounting groove is larger than an inclination angle of the first lip portion with respect to a bottom surface of the mounting groove . The seal according to claim 1 or 2 , wherein the bent portion divides a reaction force from the counterpart member acting on the lip portion between the first lip portion and the second lip portion. Wood. When the sealing material mounted in the mounting groove seals the gap with the mating member, the first lip portion contacts the mating member, and the bent portion and the second lip portion are the mating member. The sealing material according to any one of claims 1 to 3, wherein the sealing material is not in contact with the member. The first lip portion is elastically deformed prior to the second lip portion by a reaction force from the mating member, and the second lip portion starts elastic deformation after the first lip portion completes elastic deformation. The sealing material according to any one of claims 1 to 4, characterized in that:

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