JP2017015146A - Seal ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a seal ring that can be manufactured in less-expensive manner through an injection molding of thermoplastic resin composition and that can reduce leakage of fluid.SOLUTION: This invention relates to a seal ring that is integrally formed by thermoplastic resin composition of an entire ring-like shape having one gap at its circumferential part including a ring main body and a first convex part 21*a second convex part 22 extending from a first part*a second end part of the ring main body in a circumferential direction and arranged there. A cross sectional shape of the ring main body 1 is circular, the first convex part 21 and the second convex part 22 have a circular cross section of the ring main body 1 divided into two segments at a separation line Lc to cause a first corresponding plane 41*a second corresponding plane 42 to be faced to each other and the first convex part 21 and the second convex part 22 are set to a size not exceeding a basic rectangular shape under a state in which cut-out portions of the first convex part 21 and the second convex part 22 are overlapped to each other are closed.SELECTED DRAWING: Figure 7

Description

  The present invention relates to a seal ring.

  Conventionally, it has a generally annular overall shape with a cut at one circumference, has a ring main body, a first convex part and a second convex part that protrude in the circumferential direction from both ends of the ring main body, and is compressed A seal ring for sealing between the movable scroll of the machine and the housing is known, and the material thereof is mainly PTFE (polytetrafluoroethylene) (see, for example, Patent Document 1 and Patent Document 2).

JP 2007-247526 A JP-A-8-276508

A conventional seal ring of this type has been manufactured by first mechanically cutting a cylindrical PTFE material and then machining such as cutting, grinding, and cutting.
Therefore, the conventional ones have the disadvantages that the number of processing steps such as machining is increased, the material loss is increased, and the manufacturing cost is high.

  On the other hand, manufacturing by injection molding is possible, but in that case, the sealing performance at the joint portion of the first convex portion and the second convex portion is lowered, and the amount of fluid (oil) leakage from the joint portion is excessive. There was a drawback. In the rocking test, it was confirmed that the amount of fluid (oil) leakage was significantly larger than that of the PTFE seal ring. It is not preferable from the viewpoint of the function of the compressor that the fluid leakage from the seal portion is extremely increased. In addition, the sliding at the time of swinging becomes unstable due to the friction of the sliding contact portion that is in sliding contact with the sealed surface of the movable scroll or the housing, and the seal gap at the joint portion of the first convex portion and the second convex portion varies in size. This increases the amount of fluid leakage.

  Therefore, an object of the present invention is to provide a seal ring that can be manufactured at low cost by injection molding of a thermoplastic resin composition and that can reduce the amount of fluid leakage from the joint portion. In particular, a seal ring suitable for a compressor that performs scrolling motion is provided.

  The seal ring according to the present invention is integrally formed with a thermoplastic resin composition in an annular overall shape having a cut at one place on the circumference, and the ring body and the first and second ends of the ring body A seal ring having first and second protrusions extending in a circumferential direction from the portion, wherein the ring body has a circular cross-sectional shape, and the first protrusion and the second protrusion The convex portion is formed by dividing the circular cross section of the ring main body into two by a separation line so that the first corresponding surface and the second corresponding surface face each other, and the first convex portion and the second convex portion are mutually The first and second protrusions are set to dimensions that do not protrude from the contour line of the cross-section of the ring body.

  The seal ring according to the present invention is integrally formed of a thermoplastic resin composition into an annular overall shape having a cut at one place on the circumference, and the ring main body, the first end of the ring main body and the first end of the ring main body. A seal ring having first and second protrusions extending in the circumferential direction from two end portions, wherein the ring body has a circular cross-sectional shape, and the first protrusion and The second convex portion divides the circular cross section of the ring main body into two by a separation line so as to face each other with the first corresponding surface and the second corresponding surface, and the first convex portion corresponds to the first corresponding surface. A cross-sectional shape in which a scraped portion is formed on the opposite side of the surface, and the first convex portion and the second convex portion are in a closed state where the first convex portion and the second convex portion overlap each other. The portion is set to a dimension that does not protrude from the outline of the cross section of the ring body.

  The ring body in the open state has a portion with a maximum radius of curvature within a range of 180 ° ± 30 ° with respect to the center point of the cut, and the first end portion extends from the portion with the maximum size. -It is set so that the radius of curvature decreases as it approaches the circumferential direction toward each of the second ends, and the overall shape is in a closed state where the first and second protrusions overlap each other. It is comprised so that it may become a perfect circle.

  According to the seal ring of the present invention, the sealing performance at the joint portion of the first convex portion and the second convex portion can be improved, and fluid leakage can be reduced. By injection molding of the thermoplastic resin composition, the dimensions can be easily set, and a high-quality and high-performance seal ring can be obtained easily and inexpensively. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, it is possible to provide a seal ring suitable for a compressor that performs a scrolling motion.

It is a compressor sectional view which illustrated the use of the seal ring concerning the present invention concretely. It is the expanded sectional view which showed one Embodiment of this invention and showed the use location. It is a top view of a break open state. It is a front view of a cut open state (illustrated with a part of the rear portion omitted). It is a top view of a break closed state. It is a front view of a break closed state. It is the expanded sectional view which showed each principal part. It is an expanded sectional view of each important part showing other embodiments. It is a principal part expanded sectional view of one modification. It is a principal part expanded sectional view of the other modification. It is a principal part expanded sectional view which shows various other embodiment. It is a principal part expanded sectional view which shows various other embodiment. It is a principal part expanded sectional view which shows a pressure receiving state. It is a principal part expanded sectional view which shows a pressure receiving state.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
As shown in FIGS. 3 and 4, the seal ring S of the present invention has an annular overall shape having a cut 5 at one place in the circumference in a free state. The seal ring S includes a ring main body 1 occupying a central angle slightly smaller than 360 °, and a first convex portion extending in a circumferential direction from the first end portion 11 and the second end portion 12 of the ring main body 1. 21. A second convex portion 22 is attached.
FIGS. 1 and 2 show the state of use, and exemplifies a case where the present invention is applied to a scroll compression mechanism 3 of a compressor 2 for an air conditioner.

The scroll compression mechanism 3 mainly includes a housing 4, a fixed scroll 6 disposed in close contact with the upper side of the housing 4, and a movable scroll 7 that meshes with the fixed scroll 6. In the housing 4, a seal groove 4 </ b> B is formed in a flat surface portion 4 </ b> A facing the lower surface (back surface) 7 </ b> A of the movable scroll 7, and the seal ring S of the present invention is inserted in the seal groove 4 </ b> B.
The seal ring S seals between the back surface 7A of the movable scroll 7 and the flat portion 4A of the housing 4 to form a back pressure space. (FIG. 2 is an enlarged view of a Y portion in FIG. 1.)

  And as shown in FIG. 3 and FIG. 4, it forms integrally with the thermoplastic resin composition in the whole shape which the cut | interruption 5 is an open state. In FIG. 3, arrow F indicates the injection direction of the molten resin at the time of injection molding, 10 is an injection gate (trace) portion, and even if it is cut as beautifully as possible with a cutting blade (not shown), There is a possibility that minute protrusions may remain, and machining such as grinding may be performed for finishing. However, except for such an injection gate trace portion 10, machining can be omitted to form an injection molding surface.

  As a thermoplastic resin composition suitable for injection molding the seal ring S of the present invention, a PES resin composition may be mentioned. The injection-molded product has the advantage that so-called burrs are less likely to occur. Furthermore, the thermal expansion coefficient is low, the shrinkability after taking out from the mold is low, and the size of the seal ring S is maintained with high accuracy, so that the above-mentioned machining can be performed. There is an advantage that it can be omitted.

Then, as shown in FIG. 3, the cut line 5 is integrally formed with a thermoplastic resin composition such as a PES resin composition in the entire shape in the open state, but the cut line 5 taken out from the injection mold. The ring body 1 of the seal ring S in the open state has a portion 13 having the maximum radius of curvature R ₁₃ (maximum size) on the side opposite to the cut 5, and the first end from the portion 13 having the maximum dimension. The curvature radii R ₁ and R ₂ gradually decrease toward each of the portion 11 and the second end portion 12 in the circumferential directions M ₁ and M ₂ , and the first end portion 11 and the second end portion 12. The radius of curvature R ₁₁ , R ₁₂ of the first convex portion 21 and the second convex portion 22 (which are small projecting dimensions) are set to be the minimum dimension, and the curvature radius of the outer peripheral surface of the first convex portion 21 and the second convex portion 22 is R ₁₁ , Same as ₁₂ .
The curvature radii R ₁₃ , R ₁ , R ₂ , R ₁₁ , R ₁₂ are the dimensions from the center point O ₁ to the outer peripheral surface of the ring body 1 as shown in FIG.

Further, in addition, in the plan view of FIG. 3, the ring body 1 in the open state has a maximum dimension within a range of 180 ° ± 30 ° with respect to the central point (center point) P ₅ of the cut 5. The site | part 13 exists. That is, θ shown in FIG. 3 is 30 °, and the portion 13 having the maximum dimension is disposed in the range of 2θ = 60 °. (In FIG. 3, L ₀ is a line indicating the diameter including the center point P _5. )

As described above, the shape and size of the cavity of the mold and the seal ring S (see FIG. 3) taken out from the cavity have an outer peripheral edge shape of ± θ (= ± on the opposite side of 180 ° with respect to the cut 5. A portion 13 having a maximum radius of curvature R ₁₃ is disposed within a range of 30 °), and is set to a non-circular shape that gradually decreases from this portion 13 toward the cut 5.
In the state of use --- the state of being attached to the seal groove 4B as shown in FIG .---- the first convex portion 21 and the second convex portion 22 overlap each other, and the cut is closed, but the cut is opened. Due to the non-circular shape described above under the state, it becomes a true circular shape with the same radius of curvature R ₀ from the center point O ₁ due to the elastic deformation, and the inside of the seal groove 4B shown in FIG. Close contact with the wall surface 14. When deformed from the cut open state (FIG. 3) to the cut closed state (FIG. 5), the portion 13 having the largest dimension is deformed so that the radius of curvature is the largest, and the first end portion 11 and the second end portion 12 side. Hardly deforms. Accordingly, the curvature radius R ₀ shown in FIG. 5 is equal to the curvature radii R ₁₁ and R ₁₂ of the end portions 11 and 12 shown in FIG.

The cross-sectional shape of the ring body 1 is circular as shown in FIGS. 7 (A) and 8 (A).
In use state shown in FIG. 2, the rear 7A such the movable scroll 7 and the first sliding contact portion 26 in sliding contact with the (movable side) the sealed plane P _1, the seal groove 4B inner wall surface 14 or the like (fixed side) and a second sliding contact portion 27 in sliding contact with the sealing plane P _2, it has. It is pressed against the corner 8 formed by the orthogonal sealed planes P ₁ and P ₂ when receiving pressure. The first and second sliding contact portions 26 and 27 are in contact with the respective planes P ₁ and P ₂ in a linear shape as a whole. However, when the pressure is high or wear occurs, the first and second sliding contact portions 26 and 27 are in contact with each other in a thin strip shape. To do.

By the way, the present invention employs a thermoplastic resin composition such as a PES resin composition, and has a circular cross section, so that the seal ring S has a gap between the back surface 7A and the flat surface portion 4A during the scroll motion. 9 has an advantage that troubles such as biting do not occur.
As shown in FIG. 7, the first convex portion 21 and the second convex portion 22 are obtained by dividing the circular cross section of the ring body 1 into two at a separation line Lc as shown in FIG. The first corresponding surface 41 and the second corresponding surface 42 face each other. Specifically, from a circular center point O ₂₀ , an orthogonal two axes (x axis, y axis) having a center angle β of 90 ° are surrounded by an arc and a string connecting two points 38 and 39 intersecting the circular outline. The cross-sectional shape of the second convex portion 22 is set to an arcuate shape.

On the other hand, as shown in FIG. 7B, the shape of the cross section of the first convex portion 21 is set so as to form a minute seal gap g. That is, the first convex portion 21 and the second convex portion 2 are prevented from protruding from the circular outline G of the cross section of the ring body 1 shown in FIG. Each circular arc portion of the convex portion 22 has a dimension (shape) that can follow the circular contour line G, and at that time, a minute seal gap g is formed between the first and second corresponding surfaces 41 and 42. The
In FIG. 7B, the separation line is a straight line inclined at 45 °, and the center angle β is 90 °, so that in the state of use shown in FIG. The two convex portions 22 are in pressure contact (sliding contact) with the sealed planes P ₁ and P _{2 in} a stable posture. Moreover, the (thin) arcuate second convex portion 22 is easily elastically deformed in the vicinity of the points 38 and 39 at both ends, and is pressed (slidably contacted) with the sealed planes P ₁ and P ₂ at the arc surface portion. In addition, since both ends of the seal gap g are closed, the sealing performance is maintained.
Further, as shown in FIG. 7D, the central angle β ₄₁ of the first corresponding surface 41 corresponding to the chord of the cross-sectional arc corresponding to the first corresponding surface 41 in the first convex portion 21 is 90 It is over °.

  In FIG. 7, additional description will be given. When the circular contour line G of the ring body 1 is made to coincide with the arc portions of the first convex portion 21 and the second convex portion 22 so as to overlap, the straight first shape A minute seal gap g is formed between the first corresponding surface 41 and the second corresponding surface 42. The seal gap g is desirably set so as to satisfy 10 μm ≦ g ≦ 100 μm. When the seal gap g exceeds 100 μm, fluid leakage increases rapidly. In this way, fluid leakage from the first and second corresponding surfaces 41 and 42 can be suppressed, and the first convex portion 21 and the second convex portion 22 protrude from the (basic) circular outline G. In addition, the sealing performance can be further improved.

Next, FIG. 8 shows another embodiment. Compared with FIG. 7 described above, the second convex portion 22 is changed from an arcuate shape to a four semicircular shape.
More specifically, the first convex portion 21 and the second convex portion 22 have a circular cross section (contour line G) of the ring body 1 and an L-shaped separation line Lc as shown in FIG. The first corresponding surface 41 and the second corresponding surface 42 face each other.
As shown in FIG. 8 (B), the second convex portion 22 extends along the second corresponding surface 42 along two orthogonal axes (x axis, y axis) whose central angle β is 90 ° from the circular center point O _20. And the arc portion corresponds to a central angle β of 90 °.
On the other hand, as shown in FIG. 8B, a notch 40 slightly larger than the second convex portion 22 is formed from the circular outline G so as to form a minute seal gap g, and the first convex portion is formed. 21 cross-sectional shape. The center angle β ₄₀ of the notch 40 is 90 °.
In the case of such a shape and size, the second convex portion 22 is in pressure contact (sliding contact) with the sealed planes P ₁ and P ₂ in a stable posture at the corner 8 under the usage state shown in FIG. . In particular, since the seal gap g is closed at the sealed planes P ₁ and P ₂ (in the cross section), the sealing performance is maintained.
The seal gap g is preferably set in the same numerical range as that of the embodiment shown in FIG.

Next, as in the modification shown in FIG. 9, the ratio of the cross-sectional area of the second convex portion 22 may be set larger than in the case of FIG. That is, if the central angle formed by two straight lines connecting the points 38 and 39 at both ends of the string of the second convex portion 22 and the central point O ₂₀ of the circular cross section is β ₄₁ , 90 ° <β ₄₁ ≦ Set to 150 °.
As shown in FIG. 13A, when the seal S is twisted in a state of being pressed against the orthogonal sealed planes P ₁ and P ₂ , there is little fluid leakage through the gap g. That's it.

Next, in the modification of FIG. 10, the ratio of the cross-sectional area of the second convex portion 22 is larger than in the case of FIG. In this way, even if the seal S is twisted under the same use condition as in FIG. 13B, the leakage of fluid through the gap g can be reduced.
FIG. 11 shows a plurality of other embodiments of the present invention. The second convex portion 22 is the same as that in FIG. 7 or FIG. 9A, but the first convex portion 21 is different from the above-described embodiment. That is, in any of FIGS. 11A to 11D, the first convex portion 21 has a cross section in which a scraping portion 33 is formed on the opposite surface side (arc surface side) of the first corresponding surface 41. Shape.
In FIG. 11A, the shaving portion 33 is a large arcuate shape, and the first convex portion 21 has an inclined piece portion 30 having a first corresponding surface 41 and an inclined linear back surface portion 25 parallel thereto. ,It is configured. In addition, you may form so that the thickness of the inclination piece part 30 may reduce gradually to any one by the back surface part 25A shown with the dashed-dotted line. That is, the alternate long and short dash line indicates that the back surface portion 25 </ b> A is free even if it is not parallel to the first corresponding surface 41.

In FIG. 11 (B), the cross-sectional shape of the shaving part 33 is a roof type, and the 1st convex part 21 is a snail shape which has the nail parts 43 and 43 at both ends. In other words, the shape of the first convex portion 21 is composed of the inclined piece portion 30 and the nail portions 43 and 43 connected to both ends thereof.
Next, in FIG.11 (C), the cross-sectional shape of the scraping part 33 is a rugby spherical shape, and the 1st convex part 21 has the 1st corresponding | compatible surface 41 of linear inclination outside, and is inside (back side). And has an arcuate curved recess.
In FIGS. 11B and 11C, it can be said that the first convex portion 21 is formed with thick reinforcing portions at both ends. Next, in FIG.11 (D), the cross-sectional shape of the 1st convex part 21 is a mowing sickle shape. That is, with the linear back surface portion 25B parallel to the first corresponding surface 41 and the linear portion 25C bent substantially at right angles to the linear back surface portion 25B, the mowing sickle shape composed of the handle portion 44 and the blade portion 45 is formed. The 1st convex part 21 is formed. The scraping portion 33 is notched with a broken line composed of a linear back surface portion 25B and a linear portion 25C.

Next, FIG. 12 shows a plurality of other embodiments. The second convex portion 22 has the same cross-sectional shape as in FIG. 8 or FIG. 10, but the first convex portion 21 is different from the above-described embodiment. That is, as shown in FIGS. 12A to 12D, the first convex portion 21 has a cross-sectional shape in which a scraping portion 33 is formed on the opposite surface side (arc surface side) of the first corresponding surface 41. .
As shown in FIG. 12 (A), an arcuate scraping portion 33 is cut out with an inclined linear portion 46. In FIG. 12B, the cut-out portion 33 is cut out with a zigzag (stepped) folding line 47. Further, in FIG. 12C, the cut-out portion 33 is cut out along the arc line 48. In FIG. 12 (D), the cut-off portion 33 is cut out with a waveform line having two arc lines 49, 49.
Accordingly, the cross-sectional shape of the first convex portion 21 is a shape in which two sector portions 50 and 50 are connected in FIG. 12A, a zigzag shape in FIG. 12B, and FIG. ) (D) is a shape in which two ginkgo leaves are connected.

In each of the embodiments shown in FIGS. 11 and 12, the circular arc portion 51 of the first convex portion 21 and the circular arc portion 52 of the second convex portion 22 are circularly formed (similar to the case of FIGS. 7 to 10). When the contour line G is overlapped (matched), a minute seal gap g is formed between the first corresponding surface 41 of the first convex portion 21 and the second corresponding surface 42 of the second convex portion 22. . The maximum dimension of the seal gap g is desirably set to 10 μm or more and 100 μm or less.
As described above, the seal ring S is in a closed state, and the first convex portion 21 and the second convex portion 22 are crossed in a cross section, and the respective arc portions 51 and 52 are formed into a circular outline G. Under the overlapped state, the seal gap g has the maximum dimension, and since this maximum dimension is set to 10 μm or more and 100 μm or less, fluid leakage from the first and second corresponding surfaces 41 and 42 can be suppressed, and Since the 1st convex part 21 and the 2nd convex part 22 do not protrude from the outline G, sealing performance improves further.

As shown in FIG. 13 and FIG. 14, in the pressure receiving state, the seal ring S is pressed against the corner 8 formed by the sealed plane P ₁ and the sealed plane P ₂ , and the first protrusion is caused by the pressure P ₀ of the fluid L. The part 21 is pressed against the second convex part 22.
When the movable scroll 7 scrolls (see FIG. 1), the first corresponding surface 41 and the second corresponding surface 42 approach the mating member --- the sealed plane P ₁ and the sealed plane P ₂ --- The first convex portion 21 is pressed against the second convex portion 22 by the pressure P _{0 of the} fluid L. When the first convex portion 21 presses the second convex portion 22, the sealing performance between both the first convex portion 21 and the second convex portion 22 is improved, and the leakage of the fluid L from the seal gap g is prevented. Decrease. The arc portion 52 of the second convex portion 22, the arc portion 51 of the first convex portion 21 and the like can be left as they are on the injection-molded surface where machining is omitted, and in addition, according to JIS B 0601. The arithmetic average roughness (Ra) of the surface measured according to the above is set to 0.1 or more and 2.0 or less to exhibit excellent sealing performance and wear resistance.

In the present invention, the thermoplastic resin composition to be injection-molded may have a flexural modulus of 1500 MPa or more and 6000 MPa or less. For example, a polysulfone resin composition, specifically, PES (polyethersulfur resin). Phon) resin composition, PSU (polysulfone) resin composition, and PPSU (polyphenylsulfone) resin composition are preferred. In particular, the flexural modulus is preferably 2000 MPa or more and 4000 MPa or less.
The PES resin composition suitable for the seal ring according to the present invention is a PES resin composition obtained by adding a compound having a layered crystal structure such as graphite powder and / or a fluororesin powder to the PES resin. Such addition makes it easy to adjust the characteristics within the above-mentioned range of bending elasticity, excellent wear resistance as a seal ring, good heat and chemical resistance, sufficient stretchability, wearability and It also has good sealing properties and is suitable for the air conditioner compressor exemplified in FIG.
In addition, as another thermoplastic resin composition, a polyarylene sulfide-based resin composition, specifically, a compound having a layered crystal structure such as the above-described graphite powder in a PPS (polyphenyl sulfide) resin, a fluororesin powder, A PPS resin composition to which a fibrous filler such as glass fiber or carbon fiber is added can also be applied.

The usage method and operation of the seal ring S described above will be described. As shown in FIGS. 13 and 14, the seal ring S is pressed against the movable scroll 7 and the corner portion 8 of the housing 4 in the pressure-receiving state, and the second convex portion 22 is disposed corresponding to the back position of the corner portion 8. Is done. As described with reference to FIGS. 7, 8, etc., the arc portion 52 of the second convex portion 22 has a central angle β of 90 ° or more, and therefore the arc portion 52 is the movable side sealed plane P of the movable scroll 7. ₁ and the fixed-side sealed plane P ₂ are simultaneously slid (pressed). This ensures a positive seal. In addition, since the arc portion 52 is pressed against the planes P ₁ and P ₂ and the contact surface pressure is high and the contact surface pressure distribution having a peak is drawn, the sealing performance is also excellent.
Moreover, even if it exists in the 1st convex part 21, 51 A of 1st corresponding surface side sides of the circular arc part 51 are movable side sealing planes so that it may illustrate in FIG. 13 (A) (B) and FIG.14 (B). There may be a case where P ₁ and the fixed-side sealed plane P ₂ are pressed against each other at the same time, so that the sealing performance can be further improved. The first convex portion 21 receives the pressure P _{0 of the} fluid L and elastically deforms toward the second convex portion 22 side and toward the back of the corner portion 8, so that both planes P ₁ and P ₂ are The possibility of pressure contact increases, and the size of the gap g between the first and second corresponding surfaces 41 and 42 also decreases, thereby reducing fluid leakage.

  It should be noted that fluid leakage is not allowed at all at the place where the seal ring S is used in the compressor, and the seal ring S of the present invention has the same level of sealing performance as the current PTFE seal ring. Required. That is, it is not preferable that the seal ring S has excessive fluid leakage (compared to the PTFE seal ring), but it is also not preferable that fluid leakage be excessive. In view of this, the seal ring S of the present invention can be variously changed in shape and size of the first convex portion 21 as described in various manners with reference to FIGS. The amount of deformation (easiness of deformation) of the first convex portion 21 during pressure reception can be adjusted.

As described above in detail, the seal ring according to the present invention is integrally formed of a thermoplastic resin composition in an annular overall shape having a cut 5 at one circumference, and the ring body 1 and the ring body. 1 is a seal ring having a first convex portion 21 and a second convex portion 22 extending in a circumferential direction from a first end portion 11 and a second end portion 12, and a cross section of the ring body 1. The shape is circular, and the first convex portion 21 and the second convex portion 22 are obtained by dividing the circular cross section of the ring body 1 into two by the separation line Lc, and the first corresponding surface 41 and the second corresponding surface. 42, facing each other, and in the closed state where the first convex portion 21 and the second convex portion 22 overlap each other, the first convex portion 21 and the second convex portion 22 of the ring body 1 Since it is the structure set to the dimension which does not protrude from the outline of a cross section, the 1st convex part 1 and the sealing property can be improved at the joint portion of the second convex portion 22 can be reduced fluid leakage. By injection molding of the thermoplastic resin composition, a high-quality and high-performance seal ring can be obtained easily and inexpensively. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, since the cross-sectional shape is circular, it is easy to become familiar with the sealed planes P ₁ and P ₂ , shows a mountain shape with a peak contact surface pressure distribution, and has a higher sealing performance. It becomes a ring.

Further, the ring body 1 and the first end portion 11 and the second end portion 12 of the ring body 1 are integrally formed of a thermoplastic resin composition into an annular overall shape having a cut 5 at one place on the circumference. The ring ring 1 has a circular cross-sectional shape, and the first convex portion 21 has a first convex portion 21 and a second convex portion 22 that are attached in a stretched manner in the circumferential direction. And the second convex part 22 divide the circular cross section of the ring body 1 into two parts by a separation line Lc so as to face each other with the first corresponding surface 41 and the second corresponding surface 42, and further, the first convex part The portion 21 has a cross-sectional shape in which a scraping portion 33 is formed on the opposite surface side of the first corresponding surface 41, and the first convex portion 21 and the second convex portion 22 are in a cut-closed state where they overlap each other. The first convex portion 21 and the second convex portion 22 are contour lines of the cross section of the ring body 1. Since the configuration that is set to a dimension that does not protrude, the first convex portion 21 is pressure-receiving state, easily pressed and deformed in the corner portion 8 formed at the sealed plane P _1, P ₂ orthogonal, more Sealability is improved. Furthermore, a high-quality and high-performance seal ring can be obtained easily and inexpensively by injection molding of the thermoplastic resin composition. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, since the cross-sectional shape is circular, it is easy to become familiar with the sealed planes P ₁ and P ₂ , shows a mountain shape with a peak contact surface pressure distribution, and has a higher sealing performance. It becomes a ring.

Further, the ring body 1 in the open state, the radius of curvature R ₁₃ in the range of 180 ° ± 30 ° to the central point P ₅ in the cut 5 there are sites 13 of the largest dimension, of said maximum dimension The curvature radii R ₁ and R ₂ are set so as to decrease from the portion 13 toward the first end portion 11 and the second end portion 12 in the circumferential directions M ₁ and M ₂ , respectively. Since the entire shape is configured to be a perfect circle in a closed state in which the convex portion 21 and the second convex portion 22 overlap each other, the cut 5 that is easy to manufacture a mold is in an open state. When the first convex portion 21 and the second convex portion 22 are overlapped with each other, the first convex portion 21 and the second convex portion 22 become a perfect circle and exhibit excellent sealing performance (sealing performance) with respect to the circular inner peripheral surface (sealed plane P ₂ ). To do.

DESCRIPTION OF SYMBOLS 1 Ring main body 5 Cut | interruption 11 1st edge part 12 2nd edge part 13 The site | part of the largest dimension 21 1st convex part 22 2nd convex part 33 Cutting part (concave part)
41 First Corresponding Surface 42 Second Corresponding Surface G Contour Line Lc Separation Line M ₁ , M ₂ Circumferential P ₁ Movable Side Sealed Plane P ₂ Fixed Side Sealed Plane P ₅ Center Point R ₁₃ , R ₁ , R ₂ Curvature radius

  The present invention relates to a seal ring.

  Conventionally, it has a generally annular overall shape with a cut at one circumference, has a ring main body, a first convex part and a second convex part that protrude in the circumferential direction from both ends of the ring main body, and is compressed A seal ring for sealing between the movable scroll of the machine and the housing is known, and the material thereof is mainly PTFE (polytetrafluoroethylene) (see, for example, Patent Document 1 and Patent Document 2).

JP 2007-247526 A JP-A-8-276508

A conventional seal ring of this type has been manufactured by first mechanically cutting a cylindrical PTFE material and then machining such as cutting, grinding, and cutting.
Therefore, the conventional ones have the disadvantages that the number of processing steps such as machining is increased, the material loss is increased, and the manufacturing cost is high.

  On the other hand, manufacturing by injection molding is possible, but in that case, the sealing performance at the joint portion of the first convex portion and the second convex portion is lowered, and the amount of fluid (oil) leakage from the joint portion is excessive. There was a drawback. In the rocking test, it was confirmed that the amount of fluid (oil) leakage was significantly larger than that of the PTFE seal ring. It is not preferable from the viewpoint of the function of the compressor that the fluid leakage from the seal portion is extremely increased. In addition, the sliding at the time of swinging becomes unstable due to the friction of the sliding contact portion that is in sliding contact with the sealed surface of the movable scroll or the housing, and the seal gap at the joint portion of the first convex portion and the second convex portion varies in size. This increases the amount of fluid leakage.

  Therefore, an object of the present invention is to provide a seal ring that can be manufactured at low cost by injection molding of a thermoplastic resin composition and that can reduce the amount of fluid leakage from the joint portion. In particular, a seal ring suitable for a compressor that performs scrolling motion is provided.

Seal ring according to the present invention is made form the entire shape of the annular having a cut circumferentially one place, the ring body and, on the stretched shape in the circumferential direction from the first end-second end of said ring body A seal ring having first and second protrusions attached thereto, wherein the whole is integrally formed of a thermoplastic resin composition, and the cross-sectional shape of the ring body is circular, The first convex portion and the second convex portion are formed by dividing the circular cross section of the ring main body into two by a separation line and facing each other with the first corresponding surface and the second corresponding surface, and the first convex portion and the second convex portion In the closed state where the two convex portions overlap each other, the first convex portion and the second convex portion are set to dimensions that do not protrude from the contour line of the cross section of the ring body.

The seal ring according to the present invention is made form the entire shape of the annular having a cut circumferentially one place, and the ring body, extending from the first end-second end of said ring body in the circumferential direction A seal ring having a first convex portion and a second convex portion attached in a shape, the whole being integrally formed of a thermoplastic resin composition, and the cross-sectional shape of the ring body is circular, The first convex portion and the second convex portion are formed by dividing the circular cross section of the ring main body into two by a separation line so as to face each other with the first corresponding surface and the second corresponding surface, and further, the first convex portion The portion has a cross-sectional shape in which a scraped portion is formed on the opposite side of the first corresponding surface, and the first convex portion is in a closed state where the first convex portion and the second convex portion overlap each other. The portion and the second convex portion are set to dimensions that do not protrude from the contour line of the cross section of the ring body. .

  The ring body in the open state has a portion with a maximum radius of curvature within a range of 180 ° ± 30 ° with respect to the center point of the cut, and the first end portion extends from the portion with the maximum size. -It is set so that the radius of curvature decreases as it approaches the circumferential direction toward each of the second ends, and the overall shape is in a closed state where the first and second protrusions overlap each other. It is comprised so that it may become a perfect circle.

  According to the seal ring of the present invention, the sealing performance at the joint portion of the first convex portion and the second convex portion can be improved, and fluid leakage can be reduced. By injection molding of the thermoplastic resin composition, the dimensions can be easily set, and a high-quality and high-performance seal ring can be obtained easily and inexpensively. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, it is possible to provide a seal ring suitable for a compressor that performs a scrolling motion.

It is a compressor sectional view which illustrated the use of the seal ring concerning the present invention concretely. It is the expanded sectional view which showed one Embodiment of this invention and showed the use location. It is a top view of a break open state. It is a front view of a cut open state (illustrated with a part of the rear portion omitted). It is a top view of a break closed state. It is a front view of a break closed state. It is the expanded sectional view which showed each principal part. It is an expanded sectional view of each important part showing other embodiments. It is a principal part expanded sectional view of one modification. It is a principal part expanded sectional view of the other modification. It is a principal part expanded sectional view which shows various other embodiment. It is a principal part expanded sectional view which shows various other embodiment. It is a principal part expanded sectional view which shows a pressure receiving state. It is a principal part expanded sectional view which shows a pressure receiving state.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
As shown in FIGS. 3 and 4, the seal ring S of the present invention has an annular overall shape having a cut 5 at one place in the circumference in a free state. The seal ring S includes a ring main body 1 occupying a central angle slightly smaller than 360 °, and a first convex portion extending in a circumferential direction from the first end portion 11 and the second end portion 12 of the ring main body 1. 21. A second convex portion 22 is attached.
FIGS. 1 and 2 show the state of use, and exemplifies a case where the present invention is applied to a scroll compression mechanism 3 of a compressor 2 for an air conditioner.

The scroll compression mechanism 3 mainly includes a housing 4, a fixed scroll 6 disposed in close contact with the upper side of the housing 4, and a movable scroll 7 that meshes with the fixed scroll 6. In the housing 4, a seal groove 4 </ b> B is formed in a flat surface portion 4 </ b> A facing the lower surface (back surface) 7 </ b> A of the movable scroll 7, and the seal ring S of the present invention is inserted in the seal groove 4 </ b> B.
The seal ring S seals between the back surface 7A of the movable scroll 7 and the flat portion 4A of the housing 4 to form a back pressure space. (FIG. 2 is an enlarged view of a Y portion in FIG. 1.)

  And as shown in FIG. 3 and FIG. 4, it forms integrally with the thermoplastic resin composition in the whole shape which the cut | interruption 5 is an open state. In FIG. 3, arrow F indicates the injection direction of the molten resin at the time of injection molding, 10 is an injection gate (trace) portion, and even if it is cut as beautifully as possible with a cutting blade (not shown), There is a possibility that minute protrusions may remain, and machining such as grinding may be performed for finishing. However, except for such an injection gate trace portion 10, machining can be omitted to form an injection molding surface.

  As a thermoplastic resin composition suitable for injection molding the seal ring S of the present invention, a PES resin composition may be mentioned. The injection-molded product has the advantage that so-called burrs are less likely to occur. Furthermore, the thermal expansion coefficient is low, the shrinkability after taking out from the mold is low, and the size of the seal ring S is maintained with high accuracy, so that the above-mentioned machining can be performed. There is an advantage that it can be omitted.

Then, as shown in FIG. 3, the cut line 5 is integrally formed with a thermoplastic resin composition such as a PES resin composition in the entire shape in the open state, but the cut line 5 taken out from the injection mold. The ring body 1 of the seal ring S in the open state has a portion 13 having the maximum radius of curvature R ₁₃ (maximum size) on the side opposite to the cut 5, and the first end from the portion 13 having the maximum dimension. The curvature radii R ₁ and R ₂ gradually decrease toward the respective portions 11 and 2 toward the circumferential directions M ₁ and M ₂ , and the first end portion 11 and the second end portion 12. The radius of curvature R ₁₁ , R ₁₂ of the first convex portion 21 and the second convex portion 22 (which are small projecting dimensions) are set to be the minimum dimension, and the curvature radius of the outer peripheral surface of the first convex portion 21 and the second convex portion 22 is R ₁₁ , R Same as ₁₂ .
The curvature radii R ₁₃ , R ₁ , R ₂ , R ₁₁ , R ₁₂ are the dimensions from the center point O ₁ to the outer peripheral surface of the ring body 1 as shown in FIG.

Further, in addition, in the plan view of FIG. 3, the ring body 1 in the open state has a maximum dimension within a range of 180 ° ± 30 ° with respect to the central point (center point) P ₅ of the cut 5. The site | part 13 exists. That is, θ shown in FIG. 3 is 30 °, and the portion 13 having the maximum dimension is disposed in the range of 2θ = 60 °. (In FIG. 3, L ₀ is a line indicating the diameter including the center point P _5. )

As described above, the shape and size of the cavity of the mold and the seal ring S (see FIG. 3) taken out from the cavity have an outer peripheral edge shape of ± θ (= ± on the opposite side of 180 ° with respect to the cut 5. A portion 13 having a maximum radius of curvature R ₁₃ is disposed within a range of 30 °), and is set to a non-circular shape that gradually decreases from this portion 13 toward the cut 5.
In the state of use --- the state of being attached to the seal groove 4B as shown in FIG .---- the first convex portion 21 and the second convex portion 22 overlap each other, and the cut is closed, but the cut is opened. Due to the non-circular shape described above under the state, it becomes a true circular shape with the same radius of curvature R ₀ from the center point O ₁ due to the elastic deformation, and the inside of the seal groove 4B shown in FIG. Close contact with the wall surface 14. When deformed from the cut open state (FIG. 3) to the cut closed state (FIG. 5), the portion 13 having the largest dimension is deformed so that the radius of curvature is the largest, and the first end portion 11 and the second end portion 12 side. Hardly deforms. Accordingly, the curvature radius R ₀ shown in FIG. 5 is equal to the curvature radii R ₁₁ and R ₁₂ of the end portions 11 and 12 shown in FIG.

The cross-sectional shape of the ring body 1 is circular as shown in FIGS. 7 (A) and 8 (A).
In use state shown in FIG. 2, the rear 7A such the movable scroll 7 and the first sliding contact portion 26 in sliding contact with the (movable side) to be tightly sealed surface (plane) P _1, the seal groove 4B inner wall surface 14 or the like (fixing and a second sliding contact portion 27 in sliding contact with the side) to be tightly sealed surface (curved surface) P _2, has. The corner portion 8 formed by the dense orthogonal shaped sealing surfaces P _1, P _2, is pressed against the time of receiving. The first and second sliding contact portions 26 and 27 are in contact with the sealed surfaces P ₁ and P ₂ in a linear shape as a whole. However, when the pressure is high or wear occurs, the first and second sliding contact portions 26 and 27 are thin strips. To touch.

By the way, the present invention employs a thermoplastic resin composition such as a PES resin composition, and has a circular cross section, so that the seal ring S has a gap between the back surface 7A and the flat surface portion 4A during the scroll motion. 9 has an advantage that troubles such as biting do not occur.
As shown in FIG. 7, the first convex portion 21 and the second convex portion 22 are obtained by dividing the circular cross section of the ring body 1 into two at a separation line Lc as shown in FIG. The first corresponding surface 41 and the second corresponding surface 42 face each other. Specifically, from a circular center point O ₂₀ , an orthogonal two axes (x axis, y axis) having a center angle β of 90 ° are surrounded by an arc and a string connecting two points 38 and 39 intersecting the circular outline. The cross-sectional shape of the second convex portion 22 is set to an arcuate shape.

On the other hand, as shown in FIG. 7B, the shape of the cross section of the first convex portion 21 is set so as to form a minute seal gap g. That is, the first convex portion 21 and the second convex portion 2 are prevented from protruding from the circular outline G of the cross section of the ring body 1 shown in FIG. Each circular arc portion of the convex portion 22 has a dimension (shape) that can follow the circular contour line G, and at that time, a minute seal gap g is formed between the first and second corresponding surfaces 41 and 42. The
In FIG. 7B, the separation line Lc indicates a straight line inclined at 45 °, and the center angle β is 90 °. Therefore, under the use state shown in FIG. the second protrusions 22 are pressed against (sliding) in a stable position with respect to the tight seal surfaces P _{1, P 2.} Moreover, (thin) the second convex portion 22 is arcuate, the points 38 and 39 near the ends easily elastically deformed at circular surface, to be tight sealed surfaces P _1, pressed against the _{P 2} (sliding contact). In addition, since both ends of the seal gap g are closed, the sealing performance is maintained.
Further, as shown in FIG. 7D, the central angle β ₄₁ of the first corresponding surface 41 corresponding to the chord of the cross-sectional arc corresponding to the first corresponding surface 41 in the first convex portion 21 is 90 It is over °.

  In FIG. 7, additional description will be given. When the circular contour line G of the ring body 1 is made to coincide with the arc portions of the first convex portion 21 and the second convex portion 22 so as to overlap, the straight first shape A minute seal gap g is formed between the first corresponding surface 41 and the second corresponding surface 42. The seal gap g is desirably set so as to satisfy 10 μm ≦ g ≦ 100 μm. When the seal gap g exceeds 100 μm, fluid leakage increases rapidly. In this way, fluid leakage from the first and second corresponding surfaces 41 and 42 can be suppressed, and the first convex portion 21 and the second convex portion 22 protrude from the (basic) circular outline G. In addition, the sealing performance can be further improved.

Next, FIG. 8 shows another embodiment. Compared with FIG. 7 described above, the second convex portion 22 is changed from an arcuate shape to a four semicircular shape.
More specifically, the first convex portion 21 and the second convex portion 22 have a circular cross section (contour line G) of the ring body 1 and an L-shaped separation line Lc as shown in FIG. The first corresponding surface 41 and the second corresponding surface 42 face each other.
As shown in FIG. 8 (B), the second convex portion 22 extends along the second corresponding surface 42 along two orthogonal axes (x axis, y axis) whose central angle β is 90 ° from the circular center point O _20. And the arc portion corresponds to a central angle β of 90 °.
On the other hand, as shown in FIG. 8B, a notch 40 slightly larger than the second convex portion 22 is formed from the circular outline G so as to form a minute seal gap g, and the first convex portion is formed. 21 cross-sectional shape. The center angle β ₄₀ of the notch 40 is 90 °.
For such a shape and dimensions, 13 under use state of (B), the second convex portions 22 are pressed against (sliding) in a stable posture at the corners 8 to be tightly sealed surface P _1, P ₂ . In particular, the seal gap g is (At a cross section) are closed at the tightly sealed surface P _1, P _2, sealing is maintained.
The seal gap g is preferably set in the same numerical range as that of the embodiment shown in FIG.

Next, as in the modification shown in FIG. 9, the ratio of the cross-sectional area of the second convex portion 22 may be set larger than in the case of FIG. That is, if the central angle formed by two straight lines connecting the points 38 and 39 at both ends of the string of the second convex portion 22 and the central point O ₂₀ of the circular cross section is β ₄₁ , 90 ° <β ₄₁ ≦ Set to 150 °.
As shown in FIG. 13 (A), while pressed against the tightly sealing surfaces P _1, P ₂ orthogonal when twisting the seal ring S occurs, leakage of the fluid is small of a gap g I'll do it.

Next, in the modification of FIG. 10, the ratio of the cross-sectional area of the second convex portion 22 is larger than in the case of FIG. In this way, even if the seal ring S is twisted under the same use condition as in FIG. 13B, the fluid leakage through the gap g can be reduced.
FIG. 11 shows a plurality of other embodiments of the present invention. The second convex portion 22 is the same as that in FIG. 7 or FIG. 9A, but the first convex portion 21 is different from the above-described embodiment. That is, in any of FIGS. 11A to 11D, the first convex portion 21 has a cross section in which a scraping portion 33 is formed on the opposite surface side (arc surface side) of the first corresponding surface 41. Shape.
In FIG. 11A, the shaving portion 33 is a large arcuate shape, and the first convex portion 21 has an inclined piece portion 30 having a first corresponding surface 41 and an inclined linear back surface portion 25 parallel thereto. ,It is configured. In addition, you may form so that the thickness of the inclination piece part 30 may reduce gradually to any one by the back surface part 25A shown with the dashed-dotted line. That is, the alternate long and short dash line indicates that the back surface portion 25 </ b> A is free even if it is not parallel to the first corresponding surface 41.

In FIG. 11 (B), the cross-sectional shape of the shaving part 33 is a roof type, and the 1st convex part 21 is a snail shape which has the nail parts 43 and 43 at both ends. In other words, the shape of the first convex portion 21 is composed of the inclined piece portion 30 and the nail portions 43 and 43 connected to both ends thereof.
Next, in FIG.11 (C), the cross-sectional shape of the scraping part 33 is a rugby spherical shape, and the 1st convex part 21 has the 1st corresponding | compatible surface 41 of linear inclination outside, and is inside (back side). And has an arcuate curved recess.
In FIGS. 11B and 11C, it can be said that the first convex portion 21 is formed with thick reinforcing portions at both ends. Next, in FIG.11 (D), the cross-sectional shape of the 1st convex part 21 is a mowing sickle shape. That is, with the linear back surface portion 25B parallel to the first corresponding surface 41 and the linear portion 25C bent substantially at right angles to the linear back surface portion 25B, the mowing sickle shape composed of the handle portion 44 and the blade portion 45 is formed. The 1st convex part 21 is formed. The scraping portion 33 is notched with a broken line composed of a linear back surface portion 25B and a linear portion 25C.

Next, FIG. 12 shows a plurality of other embodiments. The second convex portion 22 has the same cross-sectional shape as in FIG. 8 or FIG. 10, but the first convex portion 21 is different from the above-described embodiment. That is, as shown in FIGS. 12A to 12D, the first convex portion 21 has a cross-sectional shape in which a scraping portion 33 is formed on the opposite surface side (arc surface side) of the first corresponding surface 41. .
As shown in FIG. 12 (A), an arcuate scraping portion 33 is cut out with an inclined linear portion 46. In FIG. 12B, the cut-out portion 33 is cut out with a zigzag (stepped) folding line 47. Further, in FIG. 12C, the cut-out portion 33 is cut out along the arc line 48. In FIG. 12 (D), the cut-off portion 33 is cut out with a waveform line having two arc lines 49, 49.
Accordingly, the cross-sectional shape of the first convex portion 21 is a shape in which two sector portions 50 and 50 are connected in FIG. 12A, a zigzag shape in FIG. 12B, and FIG. ) (D) is a shape in which two ginkgo leaves are connected.

In each of the embodiments shown in FIGS. 11 and 12, the circular arc portion 51 of the first convex portion 21 and the circular arc portion 52 of the second convex portion 22 are circularly formed (similar to the case of FIGS. 7 to 10). When the contour line G is overlapped (matched), a minute seal gap g is formed between the first corresponding surface 41 of the first convex portion 21 and the second corresponding surface 42 of the second convex portion 22. . The maximum dimension of the seal gap g is desirably set to 10 μm or more and 100 μm or less.
As described above, the seal ring S is in a closed state, and the first convex portion 21 and the second convex portion 22 are crossed in a cross section, and the respective arc portions 51 and 52 are formed into a circular outline G. Under the overlapped state, the seal gap g has the maximum dimension, and since this maximum dimension is set to 10 μm or more and 100 μm or less, fluid leakage from the first and second corresponding surfaces 41 and 42 can be suppressed, and Since the 1st convex part 21 and the 2nd convex part 22 do not protrude from the outline G, sealing performance improves further.

As shown in FIGS. 13 and 14, pressure-receiving state, the seal ring S is pressed against the corner portion 8 formed by the tight sealing surface P ₁ and the Secret sealing surface P _2, the first projection by the pressure P ₀ of the fluid L The part 21 is pressed against the second convex part 22.
The movable scroll 7 is scroll movement (see FIG. 1) that is, the mating member ─── be tightly sealed surface P _1, first corresponding surface 41 and the second corresponding surface 42 approaches the target tightly sealing surface P ₂ ───, The first convex portion 21 is pressed against the second convex portion 22 by the pressure P _{0 of the} fluid L. When the first convex portion 21 presses the second convex portion 22, the sealing performance between both the first convex portion 21 and the second convex portion 22 is improved, and the leakage of the fluid L from the seal gap g is prevented. Decrease. The arc portion 52 of the second convex portion 22, the arc portion 51 of the first convex portion 21 and the like can be left as they are on the injection-molded surface where machining is omitted, and in addition, according to JIS B 0601. The arithmetic average roughness (Ra) of the surface measured according to the above is set to 0.1 or more and 2.0 or less to exhibit excellent sealing performance and wear resistance.

In the present invention, the thermoplastic resin composition to be injection-molded may have a flexural modulus of 1500 MPa or more and 6000 MPa or less. For example, a polysulfone resin composition, specifically, PES (polyethersulfur resin). Phon) resin composition, PSU (polysulfone) resin composition, and PPSU (polyphenylsulfone) resin composition are preferred. In particular, the flexural modulus is preferably 2000 MPa or more and 4000 MPa or less.
The PES resin composition suitable for the seal ring according to the present invention is a PES resin composition obtained by adding a compound having a layered crystal structure such as graphite powder and / or a fluororesin powder to the PES resin. Such addition makes it easy to adjust the characteristics within the above-mentioned range of bending elasticity, excellent wear resistance as a seal ring, good heat and chemical resistance, sufficient stretchability, wearability and It also has good sealing properties and is suitable for the air conditioner compressor exemplified in FIG.
In addition, as another thermoplastic resin composition, a polyarylene sulfide-based resin composition, specifically, a compound having a layered crystal structure such as the above-described graphite powder in a PPS (polyphenyl sulfide) resin, a fluororesin powder, A PPS resin composition to which a fibrous filler such as glass fiber or carbon fiber is added can also be applied.

The usage method and operation of the seal ring S described above will be described. As shown in FIGS. 13 and 14, the seal ring S is pressed against the movable scroll 7 and the corner portion 8 of the housing 4 in the pressure-receiving state, and the second convex portion 22 is disposed corresponding to the back position of the corner portion 8. Is done. Arc portion 52 of the second convex portion 22, FIG. 7, as described in FIG. 8 or the like, because it has a more than 90 ° around the angle beta, the arcuate portion 52, the movable side to be tightly sealed surface P of the movable scroll 7 _1, and, with respect to the fixed side to be tightly sealed surface P _2, at the same time sliding (pressure). This ensures a positive seal. In addition, since the arc portion 52 is pressed against the sealed surfaces P ₁ and P ₂ and the contact surface pressure is high and the contact surface pressure distribution having a peak is drawn, the sealing performance is also excellent.
Further, as illustrated in even the first protrusion 21 Figure 13 (A) (B) and FIG. 14 (B), the first correspondence surface side end portion 51A is movable to be close sealing surface of the arc portion 51 P _1, with respect to the fixed side to be tightly sealed surface P _2, at the same time there is also the case of pressure, can be improved further sealing performance. The first convex portion 21 receives the pressure P _{0 of the} fluid L, and elastically deforms toward the second convex portion 22 side and toward the back of the corner portion 8, so that both the sealed surfaces P ₁ and P ₂ Thus, the possibility of pressure contact is increased, and the dimension of the gap g between the first and second corresponding surfaces 41 and 42 is also reduced, thereby reducing fluid leakage.

  It should be noted that fluid leakage is not allowed at all at the place where the seal ring S is used in the compressor, and the seal ring S of the present invention has the same level of sealing performance as the current PTFE seal ring. Required. That is, it is not preferable that the seal ring S has excessive fluid leakage (compared to the PTFE seal ring), but it is also not preferable that fluid leakage be excessive. In view of this, the seal ring S of the present invention can be variously changed in shape and size of the first convex portion 21 as described in various manners with reference to FIGS. The amount of deformation (easiness of deformation) of the first convex portion 21 during pressure reception can be adjusted.

As described in detail above, the seal ring according to the present invention is made form the entire shape of the annular having a cut 5 in the circumferential one place, the ring body 1, a first end of the ring body 1 11 - A seal ring having a first convex portion 21 and a second convex portion 22 attached in a stretched manner in the circumferential direction from the second end portion 12, the whole being integrally formed of a thermoplastic resin composition, The cross-sectional shape of the ring main body 1 is a circle, and the first convex portion 21 and the second convex portion 22 are divided into two by dividing the circular cross-section of the ring main body 1 by a separation line Lc. 41. The first convex portion 21 and the second convex portion 22 are in a closed state where the first convex portion 21 and the second convex portion 22 overlap each other with the second corresponding surfaces 42 facing each other. Is configured to have a dimension that does not protrude from the outline of the cross section of the ring body 1. Since, the first convex portion 21 sealing performance can be improved in the joint portion of the second convex portion 22 can be reduced fluid leakage. By injection molding of the thermoplastic resin composition, a high-quality and high-performance seal ring can be obtained easily and inexpensively. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, by cross-sectional shape is circular, amenable against the tightly sealing surfaces P _1, P _2, and the contact surface pressure distribution indicates chevron having a peak, sealability higher performance of the seal It becomes a ring.

Moreover, made form the entire shape of the annular having a cut 5 in the circumferential one place, the ring body 1, attached to the stretched shape from the first end 11, second end 12 of the ring body 1 in the circumferential direction A seal ring having the first convex portion 21 and the second convex portion 22 that are formed integrally with a thermoplastic resin composition, and the cross-sectional shape of the ring body 1 is circular, The first convex portion 21 and the second convex portion 22 divide the circular cross section of the ring body 1 into two at the separation line Lc, and face each other with the first corresponding surface 41 and the second corresponding surface 42, Further, the first convex portion 21 has a cross-sectional shape in which a scraped portion 33 is formed on the opposite side of the first corresponding surface 41, and the first convex portion 21 and the second convex portion 22 are mutually connected. In the closed cut overlapped state, the first convex portion 21 and the second convex portion 22 of the ring body 1 are Since the configuration that is set to a dimension that does not protrude from the cross-sectional contour, the first convex portion 21 is pressure-receiving state, pressing the corner portion 8 formed by the tight sealing surface P _1, P ₂ perpendicular It is easy to deform and the sealing performance is further improved. Furthermore, a high-quality and high-performance seal ring can be obtained easily and inexpensively by injection molding of the thermoplastic resin composition. Machining such as cutting / grinding / cutting can be omitted, material loss is reduced, and manufacturing can be performed at low cost. In particular, by cross-sectional shape is circular, amenable against the tightly sealing surfaces P _1, P _2, and the contact surface pressure distribution indicates chevron having a peak, sealability higher performance of the seal It becomes a ring.

Further, the ring body 1 in the open state, the radius of curvature R ₁₃ in the range of 180 ° ± 30 ° to the central point P ₅ in the cut 5 there are sites 13 of the largest dimension, of said maximum dimension The curvature radii R ₁ and R ₂ are set so as to decrease from the portion 13 toward the first end portion 11 and the second end portion 12 in the circumferential directions M ₁ and M ₂ , respectively. Since the entire shape is configured to be a perfect circle in a closed state in which the convex portion 21 and the second convex portion 22 overlap each other, the cut 5 that is easy to manufacture a mold is in an open state. 1 protrusion 21 and the second convex portion 22, under overlapping use, become a true circle, exerts a circular inner peripheral surface excellent sealing performance (sealability) against (to be tightly sealed surface P ₂₎ To do.

DESCRIPTION OF SYMBOLS 1 Ring main body 5 Cut | interruption 11 1st edge part 12 2nd edge part 13 The site | part of the largest dimension 21 1st convex part 22 2nd convex part 33 Cutting part (concave part)
41 first correspondence face 42 second corresponding surface G outline Lc separation line M _{1, M 2} circumferential P ₁ movable object tightly sealed surface P ₂ stationary object tightly sealed surface P ₅ midpoint _{R 13,} R 1, R ₂ of curvature radius

Claims (3)

The ring body (1) and the first end (11) of the ring body (1) are integrally formed with a thermoplastic resin composition into an annular overall shape having a cut (5) at one circumference. A seal ring having a first convex portion (21) and a second convex portion (22) attached in a stretched manner in the circumferential direction from the second end portion (12),
The cross-sectional shape of the ring body (1) is a circle, and the first protrusion (21) and the second protrusion (22) are separated from the circular cross-section of the ring body (1) by a separation line (Lc). ) To divide into two and make the first corresponding surface (41) and the second corresponding surface (42) face each other,
The first convex portion (21) and the second convex portion (22) are in a closed state where the first convex portion (21) and the second convex portion (22) overlap each other, and the first convex portion (21) and the second convex portion (22) are A seal ring having a dimension that does not protrude from the outline of the cross section of 1). The ring body (1) and the first end (11) of the ring body (1) are integrally formed with a thermoplastic resin composition into an annular overall shape having a cut (5) at one circumference. A seal ring having a first convex portion (21) and a second convex portion (22) attached in a stretched manner in the circumferential direction from the second end portion (12),
The cross-sectional shape of the ring body (1) is a circle, and the first protrusion (21) and the second protrusion (22) are separated from the circular cross-section of the ring body (1) by a separation line (Lc). ) So that the first corresponding surface (41) and the second corresponding surface (42) face each other, and the first convex portion (21) is the opposite surface of the first corresponding surface (41). It has a cross-sectional shape with a cut-off portion (33) formed on the side,
The first convex portion (21) and the second convex portion (22) are in a closed state where the first convex portion (21) and the second convex portion (22) overlap each other, and the first convex portion (21) and the second convex portion (22) are A seal ring having a dimension that does not protrude from the outline of the cross section of 1). The ring body (1) in the open state has a maximum radius of curvature (R ₁₃ ) within a range of 180 ° ± 30 ° with respect to the center point (P ₅ ) of the cut (5) (13) And a radius of curvature (as it approaches the circumferential direction (M ₁ ) (M ₂ ) from the maximum dimension portion (13) toward each of the first end (11) and the second end (12). R ₁ ) (R ₂ ) is set so as to decrease, and the overall shape becomes a true circle in a closed state where the first convex portion (21) and the second convex portion (22) overlap each other. The seal ring according to claim 1 or 2, configured as described above.

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