KR20060048832A - Scroll compressor - Google Patents

Abstract

An object of the present invention is to increase the compression ratio of a scroll compressor and to reduce the power loss due to overcompression.

Compression to move to the center side while reducing the volume between the two wraps by combining the fixed scroll 10 and the movable scroll 20, which have spiral wraps 12 and 22 installed on the inner surfaces of the hard plates 11 and 21, respectively. The yarns S1 and S2 are formed. The inner circumferential surface 12b of one lap is connected to the first portion 12b1 made of a part of the inner spiral surface H2 slidably contacted with the outer circumferential surface 22a of the other lap, and continuously connected to the first portion. A concave arc-shaped second portion 12b2 which is in sliding contact with the desired arc surface 22c of the central end portion of the side wrap, and is located radially outward from the extension surface of the second portion, and is connected to the desired arc surface. It consists of the 4th part 12b4 used, and the 3rd part 12b3 connected to a 4th part discontinuously connected to a 2nd part, and is rapidly separated from an outward surface of the said 2nd part, and connected to a 4th part.

Scroll Compressor, Hard Plate, Wrap, Wear Resistant Plate, Spiral Face

Description

Scroll Compressor {SCROLL COMPRESSOR}

BRIEF DESCRIPTION OF THE DRAWINGS Explanatory drawing of the shape of the center part of the scroll of 1st Embodiment of the scroll compressor by this invention.

FIG. 2 is a front sectional view of a central portion of the first embodiment shown in FIG.

3 is a cross-sectional view taken along line 3-3 of FIG.

4 is an explanatory view of the shape of the center portion of the scroll of the second embodiment of the scroll compressor according to the present invention;

5 is a front sectional view of a central portion of the second embodiment shown in FIG. 4;

6 is a sectional view taken along line 6-6 of FIG.

FIG. 7 is an enlarged sectional view taken along line 7-7 of FIG. 5; FIG.

Fig. 8 is a diagram showing the change characteristic of the communication area between the compression chamber and the central chamber with respect to the swing angle of the movable scroll.

9 is a view corresponding to FIG. 7 in an example of the prior art. FIG.

10 is an explanatory diagram of an example of a scroll compressor according to the prior art.

<Explanation of symbols for the main parts of the drawings>

10: fixed scroll

11: fixed side plate

11a, 21a: inside

11b, 21b: storing recess

12: fixed side wrap

12a, 22a: outer circumference

12b, 22b: inner circumference

12b1: first part

12b2: second part

12b3: third part

12b4: fourth part

12c, 22c: Sowon arc

14: arc surface

15: discharge hole

18, 28: wear protection plate

20: movable scroll

21: movable side plate

22: movable side wrap

H1: Outer spiral surface (outer involute surface)

H2: Inner spiral surface (inner involute surface)

01: center axis

P1: winding start point

P1, P4: Center

P5: first seal off position

S1, S2: compression chamber

S3: Central room

[Document 1] Japanese Unexamined Patent Publication No. 2000-120565

TECHNICAL FIELD The present invention relates to scroll compressors, in particular to scroll compressors having a higher compression ratio and less power loss due to compression.

As a scroll compressor which reduced the power loss by overcompression, there exists a technique disclosed by Unexamined-Japanese-Patent No. 2000-120565 (patent document 1). This is a fixed scroll with a spiral wrap made of involute curves on a hard plate with a discharge hole in the center, and a spiral scroll with a spiral wrap made of involute curves on a hard plate facing the fixed scroll. A scroll compressor comprising a plurality of compression chambers each engaged with each other, wherein the winding start portion of each scroll lap includes an outer arc with a lap tip connected smoothly to a winding start point of an outer involute curve and an inner involute. The center point of the outer arc is formed on the tangent of the base circle passing through the winding start point of the outer involute curve, while the contact point of the outer circle and the inner circle is the outer circle. With the configuration installed on a straight line connecting the center point of the inner circle and the center point of the inner arc It can control. According to such a structure, the gas passage immediately after each compression chamber is communicated with the center chamber in which the discharge hole is formed, reduces the power loss accompanying overcompression by discharge resistance, and reduces the increase of the compressor input, thereby reducing the compressor efficiency. The effect can be improved.

[Patent Document 1] Japanese Unexamined Patent Application Publication No. 2000-120565 (paragraph [0006], paragraph [0015], FIGS. 2 to 4).

However, in the prior art including Patent Document 1, in order to increase the compression ratio without increasing the trunk diameter of the scroll compressor, it is necessary to extend the spiral of the scroll to the center side to speed up the starting point of the spiral. As the yarn becomes narrower, it is difficult to secure the communication area between each compression chamber and the central chamber, and the effect of reducing the discharge resistance is insufficient to increase the power loss due to overcompression. Moreover, when the inner circular arc is enlarged in order to secure the communication area between each compression chamber and the central chamber, the thickness of the center end portion of the scroll wrap becomes small, resulting in a problem of insufficient strength of the portion.

This problem will be described in more detail with reference to Fig. 10 showing the prior art prior to Patent Document 1. This scroll compressor consists of a pair of fixed side scroll wraps 1 and a movable side scroll wrap 2, and the movable side wraps 2 are assembled so as to pivot without rotating against the fixed side wraps 1. . The inner circumferential surface 1b of the fixed side wrap 1 and the outer circumferential surface 2a of the movable side wrap 2 and the inner circumferential surface 2b of the movable side wrap 2 and the outer circumferential surface 1a of the fixed side wrap 1 are plural parts. In contact with each other, a plurality of compression chambers T1 and T2 are formed therebetween, and a central portion is formed between the inner circumferential surface 1b of the fixed side wrap 1 and the inner circumferential surface 2b of the movable side wrap 2. The center chamber T3 is formed, and the discharge plate 5 opened in the center chamber T3 is formed in the hard plate (not shown) of the fixed side wrap 1.

The fixed side wrap 1 consists of the outer circumferential surface 1a, the inner circumferential surface 1b, and the small arc surface 1c which connects the center side front-end | tip part of these peripheral surfaces 1a and 1b continuously. The outer circumferential surface 1a is a part of an involute based on the circle 1d of the double-dot chain line, and the connection point Q1 with the small arc surface 1c is the winding start point. The inner circumferential surface 1b is a short surface which continuously connects the spiral surface 1b1, which is part of an involute based on the circle 1d common to the outer circumferential surface 1a, and the spiral surface 1b1 and the small arc surface 1c. It consists of the plane 1b2, and the connection point Q2 with the plane 1b2 becomes the winding start point of the spiral surface 1b1. The shape of the movable side wrap 2 is basically the same as the shape of the fixed side wrap 1.

As shown in Fig. 10, when the movable side wrap 2 turns without rotating against the fixed side wrap 1, the center Q4 of the desired arc surface 2c of the movable side wrap 2 is the center axis O1. ) Rotates about the same radius as the turning radius, and concomitantly, both compression chambers T1 and T2 move to the center side while the volume gradually decreases, and the gas enclosed therein is compressed. The movable side wrap 2 reaches the position of the two-dot chain line 2A, and the winding start point Q1 of the outer circumferential surface 2a is the sealed off position Q5 of the inner circumferential surface 1b of the fixed side wrap 1. After reaching, as shown by the dashed lines 2B and 2C, the movable side wrap 2 is separated from the inner circumferential surface 1b of the fixed side wrap 1, whereby the inner circumferential surface 1b and the movable side wrap The gas compressed in each of the compression chambers T1 and T2 is fed into the central chamber T3 through a communication path formed between the minor arc surface 2c of (2). The broken line c of FIG. 8 shows the change characteristic of the communication area of this communication path with respect to the turning angle of the movable side wrap 2. As shown in FIG. The communication area between the inner circumferential surface 1b of the fixed side wrap 1 and the small arc surface 2c of the movable side wrap 2 begins to open in the sealed off position Q5 as indicated by the broken line c. It is gradually increased. Therefore, the communication area between each of the compression chambers T1 and T2 and the central chamber T3 immediately after the start of discharge is not sufficient, so that the gas in each of the compression chambers T1 and T2 is overcompressed to cause power loss. There is.

In the scroll compressor shown in Fig. 10, when the compression ratio is to be increased without increasing the body diameter, the winding starting point Q1 of the outer circumferential surfaces 1a and 2a of each scroll 1 and 2 is used as the base circle 1d. It is necessary to extend the outer circumferential surfaces 1a and 2a to the center side and move the sealing off position Q5 of the inner circumferential surfaces 1b and 2b to the center side. However, in such a case, the center chamber T3 is narrowed, and the communication path between the compression chambers T1 and T2 and the center chamber T3 after the winding start point Q1 passes through the seal-off position Q5. It is difficult to secure the power loss due to overcompression increases.

On the other hand, in patent document 1, the inner circular arc which discontinuously connects to the winding starting point (corresponding to the sealing off position Q5 of FIG. 10) of the inner involute of a lap is provided, and the circular arc is a further basic circle from the winding starting point. Since it is located outside the extending portion of the inner involute toward the side, the turning scroll rotates so that the winding start point of the outer involute curve exceeds the winding start point near the sealing off position of the inner involute. The gap between the starting point and the inner arc of the inner involute is larger than that of the prior art in which the inner arc is not provided, whereby the aforementioned effects can be obtained. However, in the technique of Patent Document 1 described above, in order to sufficiently secure the gas passage area after the start of discharge and to sufficiently prevent overcompression, the thickness of the center end of the lap is very large compared to the thickness of the lap before the start point of the winding of the inner involute. Since it is necessary to make it small, when durability is considered, the intensity | strength of this front-end | tip part is insufficient, and there exists a possibility that damage may arise by the sliding by a scroll used as a counterpart, a force by compressed gas, etc.

In addition, in order to increase the compression ratio without increasing the trunk diameter, as in the prior art shown in Fig. 10, the winding start point (corresponding to the winding starting point Q1 in Fig. 10) of the outer involute of the lap is close to the center side and the inner inverse It is necessary to move the winding start point of the lute to the center side. However, in this case, the central chamber is narrowed, making it difficult to secure a communication path between each compression chamber and the central chamber, and in order to overcome this, if the inner arc that is discontinuously connected to the starting point of winding of the involute is further placed outside, The thickness of the leading edge of the center side becomes further blurred, and the risk of damage to the leading edge is further increased.

An object of the present invention is to solve each of these problems by forming a concave circular arc surface in sliding contact with the tip of the other lap pivoted about it on the inner peripheral surface of the lap.

For this reason, the scroll compressor according to claim 1 of the present invention has a fixed scroll in which a spiral fixed side wrap is placed on the inner surface of the fixed side hard disk, and a movable movable wrap in a spiral shape on the inner surface of the movable side hard plate. The scrolls are pivotally combined with one another so that one outer circumferential surface of the two laps is in sliding contact with the other inner circumferential surface, and the volume between the laps is gradually reduced and the volume accompanying the turning of the movable scroll relative to the fixed scroll is formed at the center of both wraps. At least one pair of compression chambers moving toward the center chamber is formed, and the outer circumferential surface and the inner circumferential surface of each wrap are formed at least a part of them by the outer spiral surface and the inner spiral surface, and at the same time, their central side ends are connected via the wish arc surface. In a scroll compressor comprising: The inner circumferential surface is in contact with the first portion consisting of a part of the inner spiral surface slidably contacted with the outer circumferential surface of the other lap, and the first arc portion is continuously connected to the first arc portion of the center side of the other lap so as to be slidably contacted. A second portion having a concave arcuate surface shape, a fourth portion located radially outward from the extended surface of the arc surface of the second portion, and connected to the small arc surface, and discontinuously connected to the second portion. It is characterized by consisting of a third part connected to the fourth part quickly outward from the extended surface of the arc surface of the part.

In the scroll compressor according to the above item, the outer circumferential surface of each lap formed by the outer spiral surface is continuously connected to the wish arc surface at the spiral starting point, and the first portion of the inner circumferential surface of each lap is pivoted with respect to the lap. The outer circumferential surface of the other lap is formed on the opposite side to the center from the vicinity of the first sealing off position that starts to fall away from the inner spiral surface of the lap at the winding start point, and the second portion of the inner circumferential surface is In the circular arc surface centering on the center axis of the turning of the small arc surface, it is formed continuously connected from the vicinity of the 1st sealing off position of a 1st part to a center side, and a 4th part is formed by a part of inner spiral surface, It is preferable to set it as the concave arc surface connected continuously to a 4th part.

In the scroll compressor according to the above item, instead of being formed by a part of the inner spiral surface, the fourth portion is located radially inward of the inner spiral surface on the minor arc surface side and radially inward of the inner spiral surface on the third portion side. It is preferable to set it as the concave arc surface located in the outer side.

In the scroll compressor according to the above items, a shallow accommodating recess is formed in the inner surface of the hard plate of each scroll in the periphery of the discharge hole formed in the central portion of the hard plate and in a portion excluding each wrap, and the thickness is equal to the depth of the accommodating recess. It is preferable to install the same or somewhat thicker anti-wear plate in the receiving recess.

1 to 3, a description will be given of a first embodiment of a scroll compressor according to the present invention. As shown mainly in Figs. 2 and 3, the scroll compressor of the present embodiment has a fixed scroll 10 composed of a fixed side wrap plate 11 and a spiral-shaped fixed side wrap 12 which is mounted on its inner surface 11a. ) And a movable scroll 20 composed of a spiral movable side wrap 22 which is mounted on the movable side plate 21 and its inner surface 21a. The movable scroll 20 is in close contact with the upper end surface of the side circumferential wall (not shown) which the outer circumferential portion of the inner surface 21a of the movable side plate 21 is installed on the entire outer circumference of the fixed side plate 11. It is movably contacted, and is assembled so that it may turn without rotating about the fixed scroll 10. As shown in FIG. Both scrolls 10 and 20 are in contact with each other such that the inner circumferential surface 12b of the fixed side wrap 12 and the outer circumferential surface 22a of the movable side wrap 22 are slidably contacted with each other in a plurality of portions, While forming the first compression chamber S1, the outer circumferential surface 12a of the fixed side wrap 12 and the inner circumferential surface 22b of the movable side wrap 22 are slidably contacted with each other in plural parts and therebetween. Are combined so as to form a plurality of second compression chambers S2. Both compression chambers S1 and S2 move to the center side while the volume decreases in sequence with the turning of the movable scroll 20 with respect to the fixed scroll 10, and the gas enclosed inside is compressed.

A central chamber S3 is formed between the inner circumferential surfaces 12b and 22b at a central portion of both wraps 12 and 22 between the two hard plates 11 and 21, and the fixed side in contact with the central chamber S3. In the hard plate 11, the circular discharge hole 15 which has the circular hole 15a in the inner surface 11a side penetrates to the pivot axis direction of the movable scroll 20, and is formed. At the outlet side of the discharge hole 15, a reed valve 17 is provided which allows outflow of gas but prevents inflow. Moreover, only the inner part 21a of the side part 15a is formed in the inner surface 21a of the movable side hard plate 21 which contacts the center room S3.

Next, the shape of each wrap 12 and 22 is demonstrated with reference to FIG. Although the shape of the fixed side wrap 12 is demonstrated below, in the case of symmetrical scrolling, the shape of both wraps 12 and 22 is the same. The fixed side wrap 12 is composed of an outer circumferential surface 12a, an inner circumferential surface 12b, and a small arc surface 12c for connecting the central side distal end portions thereof, and the outer circumferential surface 12a and the inner circumferential surface 12b. The relief is composed of an outer involute curved surface (outer spiral surface) H1 and an inner involute curved surface (inner spiral surface) H2 having a common base circle H. The outer involute curved surface H1 of the outer circumferential surface 12a is started from the winding start point P1, and the double-dotted line indicates an extended portion that reaches the base circle H of the omitted outer involute curved surface H1. The outer peripheral surface 12a is connected to the small arc surface 12c continuously (smoothly) at the winding starting point P1.

The inner circumferential surface 12b of the fixed side wrap 12 has a first portion 12b1, a second portion 12b2, a third portion 12b3, a fourth portion 12b4 and a fifth continuous from the outside toward the center side. It consists of the part 12b5. The first portion 12b1 of the inner circumferential surface 12b of the fixed side wrap 12 is part of the inner involute curved surface H2 and of the movable side wrap 22 that is pivoted in the operating direction with respect to the fixed side wrap 12. The outer peripheral surface 22a is formed in the opposite side to the center from the 1st sealing off position P5 which starts to fall from the inner involute curved surface H2 at the winding start point P1. The second portion 12b2 of the inner circumferential surface 12b has a radius centered on the central axis O1 of the line member 13 of the center P4 of the center arc front surface 22c of the center-side front end portion of the movable side wrap 22. It is the circular arc surface 14 of (r1), is continuously connected to the center side from the 1st sealing off position P5 of the 1st part 12b1, and is reaching the 2nd sealing off position P6. The radius r1 of the second portion 12b2 is the sum of the radius of the linear member 13 of the center P4 of the minor arc surface 22c and the radius of the minor arc surface 22c. Since the configuration as described above, the desired arc surface 22c of the distal end portion of the movable side wrap 22 that is pivoted with respect to the fixed side wrap 12 is beyond the first sealing off position P5, and thus the second portion 12b2. It is in contact with the sliding movement.

The fourth portion 12b4 is formed by a portion of the inner involute curved surface H2 that is an extension of the first portion 12b1, and thus is outwardly separated from the extending surface of the arc surface 14 of the second portion 12b2. have. The third portion 12b3 is provided with a large angle in the second sealing off position P6 and is discontinuously connected to the second portion 12b2, from the extended surface of the arc surface 14 of the second portion 12b2. It is a concave arc surface which is rapidly separated outward and continuously connected to the fourth portion 12b4. The fifth portion 12b5 is a short plane that is continuously connected to the fourth portion 12b4 and the arc-like surface 12c. The fourth portion 12b4 is not limited to the concave arc surface, but may be a suitable concave arc surface. In addition, the fifth part 12b5 is not limited to a flat surface and may be a smooth concave arc surface, or the fifth part 12b5 may be omitted and the fourth part 12b4 may be directly connected to the desired arc surface 12c. . Moreover, you may provide some eggs R in the 2nd sealing off position P6 which is a connection part of the 2nd part 12b2 and the 3rd part 12b3.

The dent 15a of the discharge hole 15 is formed in the inner surface 11a of the fixed side hard plate 11 in contact with the central chamber S3 and is circular when viewed from the pivot axis direction of the movable scroll 20. It surrounds the hole 15 and is eccentrically formed toward the first sealing off position P5 of the inner involute curved surface H2 of the fixed side wrap 12 of the fixed side plate 11, and the depth is constant. As shown by the double-dotted line 22A in FIG. 2, the dent 15A has a winding starting point P1 of the outer circumferential surface 22a of the lap 22 so as to be the first of the inner circumferential surface 12b of the lap 12. Although it is not in communication with the compression chamber S1 in the state located near the sealing off position P5, if the small arc surface 22c exceeds 2nd sealing off position P6, as shown by the double-dashed line 22B, a compression chamber It is communicated with S1, and the compression chamber S1 is made to communicate with the central chamber S3 also through this recessed part 15a. The positional relationship with respect to the movable side wrap 22 is the same as that of the dig 15a, except that the dig 25a formed in the movable side plate 21 has no discharge hole.

In the first embodiment configured as described above, when the movable scroll 20 pivots without rotating against the fixed scroll 10, as shown in FIG. 2, the desired arc surface 22c of the movable side wrap 22 is rotated. The center P4 pivots along the linear member 13 centered on the center axis O1, and concomitantly, both compression chambers S1 and S2 move to the center side while the volume gradually decreases, and is enclosed therein. Gas is compressed. The movable side wrap 22 passes through the position of the double-dotted line 22A, and the winding start point P1 of the fixed side wrap 12 corresponds to the sealing off position Q5 of the prior art shown in FIG. Even after exceeding the first sealing off position P5 of the inner involute curved surface H2, the desired arc surface 22c of the movable side wrap 22 is the second portion 12b2 of the inner circumferential surface 12b of the fixed side wrap 12. The gas in the compression chamber S1 is compressed because it is in sliding contact with the gas. After the desired arc surface 22c of the movable side wrap 22 reaches the second sealing off position P6 of the inner circumferential surface 12b of the fixed side wrap 12, it is movable as indicated by the double-dotted line 22C. The compression chamber (10) is separated from the inner circumferential surface 12b of the fixed side lap 12 on the desired arc surface 22c of the side wrap 22, and is thereby communicated through a communication path formed between the inner circumferential surface 12b and the small arc surface 22c. The gas compressed in S1) is fed into the central chamber S3.

Similarly, the gas in the compression chamber S2 also passes after the winding start point P1 of the fixed side wrap 12 has crossed the first sealing off position P5 of the inner involute curved surface H2 of the movable side wrap 22. After the compressed side surface 12c of the fixed side wrap 12 moves along the second portion 22b2 of the movable side wrap 22 and reaches the second sealing off position P6, the movable side wrap ( 22 is fed into the central chamber S3 through a communication path formed between the inner circumferential surface 22b of 22 and the desired arc surface 12c of the fixed side wrap 12. The dashed-dotted line a in FIG. 8 is formed between the respective inner circumferential surfaces 12b and 22b and the small arc surfaces 22c and 12c with respect to the turning angle of the movable side wrap 22 to form the compression chambers S1 and S2 and the central chamber ( It shows the change characteristic of the communication area of the communication path communicating S3). As shown in Fig. 8, the variation characteristic (c) of the communication area of the prior art shown in Fig. 10 is the first embodiment while communication is started from the sealing off position Q5 and the communication area is gradually increased. The change characteristic (a) of the communication area of the communication is started from the second sealing off position P6 which is delayed from the sealing off position Q5 (= first sealing off position P5), but the communication area rapidly increases and the communication area is increased. In the vicinity of the increase in near to saturation, the change characteristic (c) of the communication area of the prior art is followed. The change characteristic (a) of the communication area of 1st Embodiment is rapidly increasing and following the change characteristic (c) of the prior art, The 4th part 12b4 of the inner peripheral surface 12b extends of the 1st part 12b1. The third portion 12b3 is discontinuously connected to the second portion 12b2 at a second angle in the second seal-off position P6 by a part of the female inner involute curved surface H2. This is because they are rapidly outwardly separated from the extended surface of the circular arc surface 14 of 12b2.

As described above, according to the first embodiment, the communication area is formed between the respective inner circumferential surfaces 12b and 22b and the small arc surfaces 22c and 12c to communicate the compression chambers S1 and S2 with the central chamber S3. As for the change characteristic (a), compared with the change characteristic (c) of the communication area of the prior art shown in FIG. 10, a communication start position is positive by the angle difference of 1st sealing off position P5 and 2nd sealing off position P6. Compression ratio is increased because of close proximity to the center end of the wrap 12, 22, and the communication area between the compression chambers S1, S2 and the center chamber S3 is rapidly increased, so that power loss due to overcompression can be reduced. . Moreover, it is not necessary to change the winding starting point P1 of the outer involute curved surface H1 of the outer peripheral surface 12a of the laps 12 and 22 from the conventional one, and therefore the central chamber S3 is not narrowed, so that the lap of It is not necessary to make the thickness of the center side tip portion thin, and there is no fear that the strength of the tip portion is lowered. In addition, since the compression ratio can be changed only by changing the lengths of the second portions 12b2 and 22b2, such a change is also easy. In the first embodiment, the third portion 12b3 and the fourth portion 12b4 of the inner circumferential surface 12b of the respective wraps 12 and 22 are continuously connected to form a smooth concave arc surface as a whole. From the compression chambers S1 and S2 through a communication path formed between the third portion 12b3 of the inner circumferential surface 12b of one wrap 12 and the desired arc surface 22c of the other wrap 22 by Since it smoothly guides the gas flowing into (S3), it is possible to reduce the energy loss due to eddy currents.

In addition, in this 1st Embodiment, since the breaker 15a, 25a is provided, the compression chamber S1 by the communication path formed between each inner peripheral surface 12b, 22b and the small arc surface 22c, 12c mentioned above. The communication between the compression chambers S1 and S2 and the central chamber S3 by the dents 15a and 25a is also started at substantially the same time as the communication start between the S2 and the central chamber S3.

Next, the second embodiment of the scroll compressor according to the present invention will be described with reference to FIGS. In the second embodiment, abrasion between the top surfaces 12d and 22d of the wraps 12 and 22 in contact with the inner surfaces 11a and 21a of the hard plates 11 and 21 of the respective scrolls 10 and 20. The wear prevention plates 18 and 28 for preventing the damage, and change the shape of the fourth portions 12b4 and 22b4 of the inner circumferential surfaces 12b and 22b of the respective wraps 12 and 22, Since only the point which changed the shape of 15a, 25a) differs from 1st Embodiment, and the other structure is the same, this difference is mainly demonstrated.

As shown in Figs. 5 to 7, in the second embodiment, a circular discharge hole having a hole 15b in the inner surface 11a is provided on the fixed side plate 11 in contact with the central chamber P3. 15 is formed through the movable scroll 20 in the pivoting axis direction, and a reed valve 17 is provided on the outlet side of the discharge hole 15. The dent 15b is elliptical when viewed in the direction of the pivot axis of the movable scroll 20, and both sides thereof contact the outer periphery of the discharge hole 15 to form the inner involute curved surface H2 of the fixed side wrap 12. It extends in parallel toward the 1st sealing off position P5 (refer FIG. 4), and the circular arc of the front-end | tip part is located slightly inside of the 1st sealing off position P5. On the inner surface 21a of the movable side plate 21, only the digging portions 25b, such as the digging portions 75b, are formed.

On the inner surface 11a of the fixed side plate 11, a shallow accommodating recess 11b is formed in the periphery of the dig 15b, which is part of the discharge hole 15, and in a portion excluding the fixed side wrap 12. On the inner surface 21a of the movable side plate 21, a shallow accommodating recess 21b is formed in a portion excluding the periphery of the dig 25b and the movable side wrap 22. As shown in FIG. In each of the storage recesses 11b and 21b, spiral wear protection plates 18 and 28 made of a thin plate (e.g., an iron plate having a thickness of 0.3 mm) that is equal to or slightly thicker than the depth thereof are provided with each storage recess ( It is provided so that it may adhere to the bottom surface of 11b, 21b). The tip portion 18a (not shown in the anti-wear plate 28 side) on the center side of the wear-preventing plates 18 and 28 cannot be sharpened in order to prevent clogging, and a circular arc shape having a very large radius needs to be formed. Therefore, the inner surfaces 11a and 21a of the fixed side hard plates 11 and 21 which are in the vicinity thereof are not covered by the wear preventing plates 18 and 28 over a considerable range. Top surfaces 12d and 22d of the wraps 12 and 22 are provided with seals 19 and 29 in contact with the wear preventing plates 18 and 28.

As shown in Fig. 4, the fourth portion 12b4 of the inner circumferential surface 12b of the fixed side wrap 12 has a center axis O2 near the central axis 01 of the second portion 12b2. It is a part of concave arc surface K which has radius r2 about the same as radius r1 of 2 part 12b2, and 4th part 12b4 is inner spiral surface H2 on the small arc surface 12c side. It is located in the radially inner side, and is located radially outward from the inner spiral surface H2 on the third portion 12b3 side, and one end of the concave circular arc surface K has reached the first sealing off position P5. Similarly to the first embodiment, the third portion 12b3 is provided with a large angle in the second sealing off position P6 and is discontinuously connected to the second portion 12b2, so that the arc surface of the second portion 12b2 ( It is quickly separated outward from the extended surface of 14) and is continuously connected to the 4th part 12b4. As described above, in the third portion 12b3 of the second embodiment, the fourth portion 12b4 is located radially outward from the inner spiral surface H2 on the third portion 12b3 side. The fourth part 12b4 side of the part 12b3 is located radially outward from the inner involute curved surface H2 away from the extension surface of the second part 12b2 outward from the fourth part 12b4 of the first embodiment. have. Since it is comprised in this way, the desired arc surface 22c of the front end part of the movable side wrap 22 is the connection part of the 2nd part 12b2 and the 3rd part 12b3 of the inner peripheral surface 12b of the fixed side wrap 12. The communication path between the compression chambers S1 and S2 and the center chamber S3 immediately after passing through is larger than the case of the first embodiment. Further, the fourth portion 12b4 is located radially inward from the inner spiral surface H2 on the side of the small arc surface 12c, whereby the thickness I of the tip portion of the fixed side wrap 12 is less than that of the first embodiment. Grows In addition, the fourth portion 12b4 is located radially inward from the inner spiral surface H2 on the small arc surface 12c side and located radially outward from the inner spiral surface H2 on the third portion 12b3 side. An arc surface may be sufficient, and it is not necessary to be a part of the concave circular arc surface which passes through 1st sealing off position P5.

In the second embodiment configured as described above, similarly to the first embodiment, when the movable scroll 20 pivots with respect to the fixed scroll 10, both compression chambers S1 and S2 are moved to the center side while the volumes are sequentially reduced. The gas enclosed therein is compressed so that the desired arc surfaces 12c and 22c of one wrap 12 and 22 are second sealed off positions P6 of the inner circumferential surfaces 22b and 12b of the other wrap 22 and 12. If exceeding, the desired arc surfaces 12c and 22c of one of the wraps 12 and 22 are separated from the inner circumferential surfaces 22b and 12b of the other wraps 22 and 12, and the inner circumferential surfaces 22b and 12b and the desired arc surfaces 12c, The gas compressed in the compression chambers S1 and S2 through the communication path formed between 22c) is fed into the central chamber S3.

In the second embodiment, as described above, the inner peripheral surface 12b of the fixed side wrap 12 has the fourth portion 12b4 side of the third portion 12b3 more than the fourth portion 12b4 of the first embodiment. It is located radially outward from the inner involute curved surface H2 away from the extended surface of the 2nd part 12b2, and the same also applies to the movable side wrap 22. As shown in FIG. Therefore, the desired arc surface 12c, 22c of the front end part of one wrap 12 and 22 is the 2nd part 22b2, 12b2 and the 3rd part 22b3, of the inner peripheral surfaces 22b and 12b of the other wrap 22 and 12. The communication path between the compression chambers S1 and S2 and the central chamber S3 immediately after passing through the connecting portion of 12b3) is the area and the increase speed as indicated by the double-dotted line b of FIG. Since it becomes larger than the case of 1st Embodiment, the power loss by overcompression can be reduced. Further, the fourth portion 12b4 is located radially inward from the inner spiral surface H2 on the side of the arc surface 12c, whereby the thickness I of the distal end portion of the fixed side wrap 12 is increased, so The strength can be further increased.

Moreover, in this 2nd Embodiment, the wear prevention board which prevents abrasion of the inner surface 11a, 21a in the shallow accommodating recesses 11b, 21b formed in the inner surface 11a, 21a of each hard plate 11, 21 ( 18, 28) are installed. In a scroll compressor provided with such an anti-wear plate 18, the anti-wear plate 18, 28 is directly placed on the inner surface 11c of the light plates 11 and 21 (the movable side light plate 21 side is not shown). , And a step corresponding to the plate thickness of the wear preventing plates 18 and 28 occurs between the surfaces of the wear preventing plates 18 and 28 and the inner surface 11c of the hard plates 11 and 21. . In such a case, the inner surface of the hard plate 11 near the outer side of the tip portion 18a of the wear protection plate 18 as shown in FIG. In the range where 11c is not covered by the wear preventing plate 18, it corresponds to the thickness of the wear preventing plate 18 between the inner surface 11c and the top surface 22d of the movable side wrap 22 opposite thereto. There is a gap e '. Before the desired arc surface 22c of the movable side wrap 22 reaches the second sealing off position P6 of the fixed side wrap 12, as shown in Fig. 9, the center chamber is formed by this gap e '. (S3) and the compression chamber (S1) communicate with each other, the gas in the central chamber (S3) is flowed back into the compression chamber (S1) has not yet reached a predetermined output pressure, and similarly fixed to the inner surface of the movable side plate 21 The gas in the center chamber S3 is also flowed back into the compression chamber S2 by the same gap generated between the top surfaces 12d of the side wraps 12. This countercurrent gas is recompressed in the compression chambers S1 and S2, causing a problem of power loss. However, in the second embodiment described above, the inner concave portions 11a and 21a of each of the hard plates 11 and 21 are shallow storage recesses in the portions excluding the periphery of the digs 15b and 25b and the wraps 12 and 22. (11b, 21b) are formed, and in each of the storage recesses (11b, 21b), the wear prevention plates (18, 28) of thin boards having a thickness equal to or slightly thicker than that of the storage recesses (11b, 21b) are formed. Since it is provided in close contact with the bottom surface, as shown in FIG. 7, which is a sectional view of FIG. 5, the inner surfaces of the hard plates 11 and 21 near the outer side of the tip portion 18a of the wear protection plates 18 and 28. Even if the range 11c is not covered by the wear preventing plate 18, it occurs between the inner surface 11c of the hard plates 11 and 21 and the top surfaces 12d and 22d of the wraps 12 and 22 opposite thereto. The gap e is smaller than the above-described gap e 'by the depths of the storage recesses 11b and 21b. As a result, the amount of gas flowing back from the central chamber S3 to the compression chambers S1 and S2 through the gap e is reduced, so that power loss of the scroll compressor can be reduced.

In the case where the wear protection plates 18 and 28 are brought into close contact with the inner surfaces of the hard plates 11 and 21, the gas compressed in the central chamber S3 on the rear surface of the front end portions of the wear protection plates 18 and 28 or At the time of stop, liquid accumulated in the central chamber S3 may enter and cause this tip to rise, and this float may be repeatedly repeated by the top surfaces 12d and 22d of the wraps 12 and 22. The wear prevention plates 18 and 28 are formed in the shallow storage recesses 11b and 21b formed on the inner surfaces 11a and 21a of the hard plates 11 and 21, although they may be pressed against the inner surfaces of the hard plates 11 and 21. According to the present invention, since the compressed gas in the central chamber S3 or the liquid accumulated in the central chamber S3 at the time of stopping is reduced on the rear surfaces of the front ends of the wear preventing plates 18 and 28, the aforementioned The risk of breakage due to fatigue as described above is reduced.

In each of the embodiments described above, the case of the symmetrical scroll in which the pair of wraps 12 and 22 are substantially the same shape and provided a phase difference of 180 degrees has been described. However, the present invention is not limited thereto, and each wrap 12, The same applies to asymmetrical scrolls in which the length of 22) or the winding start position and the winding end position are changed.

As described above, according to the present invention, the inner circumferential surface of one lap of both scrolls which are pivoted with each other is composed of a first portion consisting of a part of the inner spiral surface slidably contacted with the outer circumferential surface of the other lap, and continuously to the first portion. A second portion of a concave arcuate shape which is connected to and is in sliding contact with the desired arc surface of the central end portion of the other lap, and is located radially outward from the extension surface of the arc surface of the second portion, and is connected to the small arc surface. And a third portion that is discontinuously connected to the second portion and rapidly displaces outwardly from the extended surface of the arc surface of the second portion, and is connected to the fourth portion. Even if the circular arc surface of the center end of the other lap is separated from the inner spiral surface of one lap, the minor arc surface is The compression chamber and the central chamber do not communicate with each other until the circular arc surface is slidably in contact with the second portion having a circular arc shape, and the circular arc surface passes through the connection portion between the second and third portions, and the circular arc surface passes through the connection portion. Communication then begins. That is, since the position where the desired arc surface of the other lap falls from the inner circumferential surface of one lap is close to the central tip of both laps, the compression ratio is high, and the third portion is discontinuously connected to the second portion, and the extended surface of the arc surface is discontinuous. It quickly falls outwards, and thereby the communication area between the compression chamber and the central chamber is rapidly increased, so that power loss due to overcompression can be reduced. Moreover, it is not necessary to change the winding start point of the outer spiral surface of the outer circumferential surface of a lap conventionally, and therefore, the central thread does not become narrow, so it is not necessary to reduce the thickness of the center side tip of the lap, and the strength of the front end is lowered. There is no fear of becoming.

The outer circumferential surface of each lap formed by the outer spiral surface is continuously connected to the wish arc surface at the spiral starting point, and the first portion of the inner circumferential surface of each lap is wound around the outer lap that is pivoted with respect to the lap. The center axis of the pivot of the center of the wish arc surface of the center side tip part of the other wrap | wire is formed in the opposite side to the center from the vicinity of the 1st sealing off position which starts to fall off from the inner spiral surface of a lap at a viewpoint. Is formed by continuously connecting from the vicinity of the first sealing off position of the first portion to the center side in a circular arc centered on the second portion, the fourth portion is formed by a portion of the inner spiral surface, and the third portion is continuous to the fourth portion. According to the invention of claim 2, wherein the third portion and the fourth portion of the inner circumferential surface of each wrap are continuously connected to each other. The above-described invention provides a smooth concave arc surface, and smoothly guides the gas flowing into the central chamber from a communication path formed between the third portion of the inner circumferential surface of one lap and the wish arc surface of the central end of the other lap. In addition to all the effects due to this, it is possible to reduce the energy loss due to the vortex of gas.

Instead of being formed by a part of the inner spiral surface, the fourth portion is a concave arc surface located radially inward from the inner spiral surface on the side of the desired arc and radially outward of the inner spiral surface on the third portion. According to the invention of 3, the communication path between the compression chamber and the central chamber immediately after the desired arc surface of the tip portion of the other wrap passes through the connecting portion of the second portion and the third portion of one inner circumferential surface is increased in area and speed of increase. Since it is increased than in the case of 2, power loss due to overcompression can be reduced, and since the thickness of the tip of the lap is increased, the strength of the tip can be further increased.

On the inner surface of the hard plate of each scroll, shallow accommodating recesses are formed in the periphery of the discharge hole formed in the center of the hard plate and in the portions excluding the wraps, and a wear preventing plate having a thickness equal to or slightly thicker than the depth of the accommodating recess is formed. According to the invention of claim 4 provided in the storage recess, the gap between the periphery of the discharge hole where the wear protection plate is not provided among the inner surfaces of the hard plate of one scroll and the top surface of the movable side wrap of the other scroll can be reduced. . This gap communicates with the central chamber and the compression chamber before the one surface of the lap reaches the connecting portion of the other second and third portions, and the compression chamber has not yet reached the predetermined output pressure. Although it causes the backflow into the inside, according to the invention of claim 4, by reducing the gap, it is possible to reduce the power loss of the scroll compressor due to such backflow.

Claims (4)

Fixed scrolls with spiral-shaped fixed side wraps mounted on the inner surface of the fixed side plate, and movable scrolls with spiral-shaped movable side wraps installed on the inner surface of the movable side plate, the outer peripheral surface of one of the two wraps At least one pair rotatably combined with each other for slidably contacting and moving between the two wraps toward the central chamber formed at the centers of the two wraps, with the volume gradually decreasing with the turning of the movable scroll relative to the fixed scroll In the scroll compressor formed of a compression chamber, wherein the outer peripheral surface and the inner peripheral surface of each wrap is formed by at least a part of them by the outer spiral surface and the inner spiral surface, and at the center end portion thereof via a wish arc surface. The inner circumferential surface of one of the wraps of the two scrolls which are pivoted with each other A first portion comprising a portion of the inner spiral surface slidably in contact with the outer circumferential surface of the side wrap, and continuously connected to the first portion so as to be able to slide with the wish arc surface of the central end portion of the other wrap; A second portion of a concave arcuate surface shape in contact, a fourth portion located radially outward from the extension surface of the arc surface of the second portion and connected to the small arc surface, and discontinuously connected to the second portion And a third portion connected to the fourth portion quickly outwardly from an extension surface of the arc surface of the second portion. The outer circumferential surface of each lap formed by said outer spiral surface is continuously connected to said wish arc surface at a spiral start point, and said first portion of the inner circumferential surface of each lap is said wrap. The outer circumferential surface of the other lap pivoted about is formed on the opposite side to the center from the vicinity of the first sealing off position that begins to fall away from the inner spiral surface of the lap at the winding start point, and the second portion of the inner circumferential surface is The fourth portion is formed by continuously connecting from the vicinity of the first sealing off position of the first portion to the center side in an arc surface centered on the center axis of the pivot of the center of the minor arc surface of the center side tip portion of the other wrap. Is formed by a portion of the inner spiral surface, and the third portion is a concave arc continuously connected to the fourth portion. A scroll compressor that is characterized by. The said 4th part is located in the radial direction inner side rather than the said inner spiral surface at the said arc surface side, and is formed more than the said inner spiral surface at the said 3rd side, instead of being formed by a part of the said inner spiral surface. A scroll compressor comprising a concave arc surface located radially outward. 4. The thickness of any one of claims 1 to 3, wherein a shallow accommodating recess is formed on an inner surface of the hard plate of each scroll to form a periphery of a discharge hole formed in a central portion of the hard plate and a portion excluding the wrap. And a wear preventing plate which is equal to or slightly thicker than the depth of the storage recess, is provided in the storage recess.

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