JP5879532B2 - Scroll compressor - Google Patents

Description

  The present invention relates to a scroll type compressor, and more particularly to a scroll type compressor capable of increasing the strength on the lap center side without reducing the compression performance.

Conventionally, for example, a scroll compressor is known as an example of a compressor that compresses refrigerant in a refrigeration cycle (see, for example, Patent Document 1).
As shown in FIG. 9, the scroll compressor 100 includes a compression container 110 formed in a cylindrical shape extending in the vertical direction, and a compression element 114 that compresses a refrigerant is disposed on the upper side of the compression container 110. The electric element 115 that drives the compression element 114 is disposed on the lower side.

  The compression mechanism 114 includes a fixed scroll 119 and an orbiting scroll 120, and the wraps 132 and 139 of the fixed scroll 119 and the orbiting scroll 120 are engaged with each other to form a plurality of compression spaces 121 therein. doing.

  The fixed scroll 119 is fixed to the casing. On the other hand, the movable scroll 120 that meshes with the fixed scroll 119 from below is integrally connected to the drive shaft 123 by inserting the eccentric shaft portion 123A of the drive shaft 123 into the bearing portion 122 provided on the lower surface. Then, the movable scroll 120 that is rotationally driven by the driving force of the motor 127 performs only revolution without rotating with respect to the fixed scroll 119, so that the volume of the compression space 121 formed between both the laps 132 and 139 is increased. Reduce and compress the refrigerant inside.

  In the scroll compressor 100 of this configuration, the refrigerant suction pipe 117 is directly connected to the suction port 111 of the compression element 114, and the inside of the compression container 110 is filled with the high-pressure refrigerant compressed by the compression element 114. A space 113 is formed. Further, the bottom of the compression container 110 serves as an oil reservoir 116 in which lubricating oil for lubricating the compression element 114 and the like is stored. On the other hand, a side surface of the compression container 110 is provided with a refrigerant suction pipe 117 that introduces refrigerant into the compression element 114 and a refrigerant discharge pipe 118 that discharges the refrigerant compressed by the compression element 114 to the outside of the apparatus. Yes.

  Further, in this scroll type compressor, an oil passage 144 through which the lubricating oil passes is formed inside the rotating shaft 123 in order to supply the lubricating oil to the compression element 114 and the bearings 128, 141, 149, etc. of the rotating shaft 123. ing. The oil passage 144 includes a lubricating oil suction port 145 formed at the lower end of the rotation shaft 123 and a paddle 146 formed at the upper portion of the suction port 145, and is formed along the axial direction of the rotation shaft 123. ing. Further, the oil passage 144 includes an oil supply port 147 for supplying lubricating oil at a position corresponding to each bearing.

  When the rotating shaft 123 rotates, the lubricating oil accumulated in the oil reservoir 116 enters the oil passage 144 from the suction port 145 of the rotating shaft 123 and is pumped upward along the paddle 146 of the oil passage 144. The pumped lubricating oil lubricates the bearings 128, 141, and 149 through the oil supply ports 147. Further, the lubricating oil pumped up to the boss accommodating portion 142 is guided to the outer peripheral portion of the main frame through a return pipe (not shown) formed in the main frame, and a discharge port (not shown) formed in the outer peripheral portion. The oil is returned to the oil sump 116 again.

JP 2008-50986 A

  By the way, in such a scroll type compressor, the compression part surrounded by the wrap of the fixed scroll and the wrap of the movable scroll is constituted by a space formed by these both laps meshing with each other. However, a discharge port is formed in the central spiral portion, which is the wrap tip portion of the fixed scroll, through the thickness direction of the end plate of the fixed scroll.

  And in the center spiral part of the front-end | tip part enclosed by the lap | wrapping of both a fixed scroll and a movable scroll, it compresses to a high voltage | pressure state, sending refrigerant gas from the compression part of a peripheral part side toward the compression part of a center part side. It is configured as follows. For this reason, especially the vicinity of the root of the central spiral portion of the wrap having a relatively thin end plate facing the discharge port is weak in strength and insufficient in strength.

  That is, this is because the difference in pressure received from the compressed refrigerant gas at the inner surface and the outer surface of the wrap of the spiral portion at the center of the fixed scroll is large, and stress is concentrated at the root of the inner surface of the wrap at the tip portion. Because it works.

  Therefore, in view of the above-described circumstances, the present invention can increase the strength at the end plate facing the through hole near the base of the wrap tip of the fixed scroll, and thus can improve the reliability and durability. An object is to provide a scroll compressor.

To achieve the above objective,
(1) The scroll compressor of the present invention is
In a scroll type compressor that includes a fixed scroll fixed inside a casing and a movable scroll meshing with the fixed scroll, and compresses a space formed between the two wraps.
The front end side of the wrap of the fixed scroll is formed thicker than the front end side of the wrap of the movable scroll.
(2) In the scroll compressor of (1) above,
Between the start point of the inner involute surface and the start point of the outer involute surface constituting the fixed scroll lap, a non-involute surface comprising an inner non-involute surface that is a concave curved surface and an outer non-involute surface that is a convex curved surface is formed. And
The non-involute surface is formed by forming the inner non-involute surface, which is the concave curved surface, into a curved surface shape having a small curvature radius, and
The through-hole forming the discharge port formed in the spiral central portion which is the wrap tip of the fixed scroll has an inner non-involute whose opening shape in the approach region facing the inner non-involute surface which is the concave curved surface is a concave curved surface Form a curved surface smaller than the radius of curvature of the surface,
A long contact hole distance is ensured between the closest edge of the periphery of the through-hole that is closest to the root of the wrap tip of the fixed scroll and the base of the wrap tip of the solid scroll. It is configured as described above.
(3) Moreover, in the scroll compressor of the above (1) or (2),
In the end plate near the periphery of the through hole that forms the discharge port, formed in the spiral center part that is the wrap tip of the fixed scroll,
The height of the vertical wall rising from the closest edge that faces the base of the wrap tip in the closest state among the peripheral edges of the through hole is high.
(4) In the scroll compressor of (3) above,
The height of the vertical wall of the through hole is formed approximately twice the thickness of the wrap at the portion facing the medium pressure chamber of the fixed scroll.
It is characterized by that.
(5) In the scroll compressor according to the above (1) to (4) , the movable scroll is always at least partially in the spiral central portion, which is the tip of the wrap , as viewed in the axial direction of the through hole of the fixed scroll. In the overlapping arrangement state, with a recess that constitutes a dummy port,
The size of the recess is larger than the size of the through-hole, and the through-hole of the fixed scroll and the recess of the movable scroll have a similar shape and are point-symmetric with a phase difference of 180 degrees from each other. Formed in a relative positional relationship reversed to
It is characterized by that.
(6) As described above, the scroll compressor according to the present invention includes the fixed scroll fixed inside the casing and the movable scroll meshing with the fixed scroll, and the spiral wrap formed on the end plate of the fixed scroll. And a spiral wrap formed on the end plate of the movable scroll, and a through-hole forming a discharge port formed through the end plate in the spiral central portion of the fixed scroll wrap With
The scroll-type compressor in which a part of the side wall of the through-hole forms a vertical wall that is displaced inward from the portion of the peripheral edge of the through-hole connected to the root of the wrap tip of the fixed scroll. In
The vertical wall is formed so that its height is approximately twice the thickness of the portion of the fixed scroll that faces the intermediate pressure chamber excluding the wrap tip of the fixed scroll ,
An inner non-involute surface that is a concave curved surface and an outer non-involute surface that is a convex curved surface that forms the tip of the wrap between the starting point of the inner involute surface and the starting point of the outer involute surface constituting the wrap of the fixed scroll The non-involute surface is formed by shifting the inner non-involute surface, which is the concave curved surface, closer to the through hole due to a curved surface shape having a smaller radius of curvature than the case of forming the involute surface. The through hole is formed so that the opening shape in the approaching area facing the inner non-involute surface that is the concave curved surface is a curved surface that is smaller than the radius of curvature of the inner non-involute surface that is the concave curved surface, and the opening area is small. It is formed.

  According to the scroll type compressor of (1) above, the end plate portion facing the through hole in the vicinity of the base of the wrap tip of the fixed scroll increases the strength of the portion by the thickness. As a result, there is an advantage that the reliability and durability of the fixed scroll can be improved.

  According to the scroll type compressor of the above (2), the nearest edge portion of the peripheral portion of the through hole in the fixed scroll that faces the root of the wrap tip of the fixed scroll in the closest state and the root of the wrap tip. It is possible to ensure a long distance between the adjacent holes. As a result, it is possible to further increase the strength of the end plate facing the through-hole at the root portion of the wrap tip of the fixed scroll, thereby further improving the reliability and durability of the fixed scroll. It is done.

  According to the scroll compressor of the above (3), the height of the vertical wall where the through hole rises from the peripheral portion facing the base of the wrap tip of the fixed scroll is increased, so that the wrap tip of the fixed scroll Since the end plate facing the through-hole at the base portion is thick, there is an advantage that the strength of the fixed scroll can be further increased accordingly.

  According to the scroll compressor of the above (4), the height of the vertical wall of the through hole is formed to be approximately twice the thickness of the fixed scroll lap facing the intermediate pressure chamber. The effect that the intensity | strength in the end plate which faces the through-hole of the root part of the lap | wrap front-end | tip part of a scroll can be raised further is also acquired.

According to the scroll type compressor of the present invention , as described in (5) above, the movable scroll is provided with a depression that constitutes a dummy port having a specific shape and a specific arrangement, so that the refrigerant gas can be discharged from the compression chamber. There is also an effect that the timing can be achieved.

According to the scroll compressor of (6) above , the height of the vertical wall is approximately twice the thickness of the portion facing the medium pressure chamber of the fixed scroll wrap, and the tip of the fixed scroll wrap The thickness of the end plate in the vicinity of the part is substantially increased, and the strength is greatly increased. In addition, by shifting the tip end portion of the fixed scroll lap closer to the through hole and reducing the opening area of the through hole, the mirror accuracy of the fixed scroll can be increased without changing the compression ratio. Moreover, since the critical hole distance can be made longer than before, the strength at the end plate facing the through hole at the base part of the wrap tip of the fixed scroll can be further increased, and thus the reliability of the fixed scroll, Durability can be further increased. For this reason, it becomes a structure without the change of the timing which communication with a compression chamber starts, and generation | occurrence | production of a bad influence can be prevented about noise, a vibration, durability, etc., without generating a load more than necessary about a bearing load.

It is a longitudinal section showing a scroll type compressor concerning one embodiment of the present invention. It is explanatory drawing which shows the state of the lower surface in the fixed scroll of the scroll compressor shown in FIG. It is a top view which shows the state of the upper surface in the movable scroll of the scroll compressor. It is sectional drawing which shows the state of the periphery of the communicating path of the scroll compressor. (A) is an enlarged view of a main part showing the vicinity of a wrap tip of a fixed scroll of the scroll compressor, (B) is a fixed scroll (specifications shown in Table 1) of a general scroll type compressor which is a comparative example. It is a principal part enlarged view which shows the lap | tip front-end | tip part vicinity of (1 fixed scroll). 5A is a cross-sectional view taken along the line VIA-VIA in FIG. 5A, and FIG. 5B is a cross-sectional view taken along the line VIB-VIB in FIG. It is explanatory drawing which shows the curved surface shape of the lap front-end | tip part vicinity in the fixed scroll of the scroll compressor shown in FIG. It is explanatory drawing which shows the relationship between the through-hole near the lap | tip front-end | tip part in the fixed scroll shown in FIG. 7, and the dummy port of a movable scroll, the relationship of the wrap thickness of both scrolls, etc. It is sectional drawing which shows the structure of the conventional common scroll type compressor.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows a scroll compressor 1 having an internal high pressure according to an embodiment of the present invention, and this compressor 1 is connected to a refrigerant circuit (not shown) in which a refrigerant circulates and performs a refrigeration cycle operation. The refrigerant is compressed by inverter control.

  The compressor 1 has a vertically long cylindrical hermetic dome-shaped casing 3. The casing 3 includes a casing body 5 that is a cylindrical body having an axis extending in the vertical direction, and a bowl-shaped upper cap having a convex surface that is welded and integrally joined to the upper end of the casing body 5. 7 and a bowl-shaped lower cap 9 which is welded and integrally joined to the lower end portion of the casing body 5 and has a convex surface protruding downward, and a pressure vessel is formed inside. ing.

  Inside the casing 3 are housed a scroll compression mechanism 11 that compresses the refrigerant and a drive motor 13 that is disposed below the scroll compression mechanism 11. The scroll compression mechanism 11 and the drive motor 13 are connected by a drive shaft 15 that is disposed so as to extend in the vertical direction in the casing 3. A high-pressure space 17 that is a gap space is formed between the scroll compression mechanism 11 and the drive motor 13.

  The scroll compression mechanism 11 includes a housing 21 that is a substantially bottomed cylindrical storage member that is open on the upper side, a fixed scroll 23 that is fastened with bolts in close contact with the upper surface of the housing 21, the fixed scroll 23, And a movable scroll 25 which is disposed between the housings 21 and meshes with the fixed scroll 23. The housing 21 is fixed to the casing body 5 on the outer peripheral surface thereof. The casing 3 is partitioned into a high-pressure space 17 below the housing 21 and a discharge space 29 above the housing 21, and the spaces 17 and 29 are formed to extend vertically on the outer periphery of the housing 21 and the fixed scroll 23. Communicating through a vertical groove (not shown).

  The drive motor 13 includes an annular stator 13A fixed to the inner wall surface of the casing 3, and a rotor 13B configured to be rotatable inside the stator 13A. The motor 13 is composed of an inverter-controlled DC motor, and a movable scroll 25 of the scroll compression mechanism 11 is drivingly connected to the rotor 13B via a drive shaft 15.

  The lower space 91 below the drive motor 13 is maintained at a high pressure, and oil is stored in the inner bottom portion of the lower cap 9 corresponding to the lower end portion thereof. In the drive shaft 15, an oil supply passage 15 </ b> B as a part of the high pressure oil supply means is formed, and the oil supply passage 15 </ b> B communicates with an oil chamber 52 on the back surface of the movable scroll 25. A pickup (not shown) is connected to the lower end of the drive shaft 15, and this pickup scoops up oil stored in the inner bottom portion of the lower cap 9. The scooped up oil passes through the oil supply passage 15B of the drive shaft 15 and is supplied to the oil chamber 52 on the back surface on the movable scroll 25 side. Then, the oil chamber 52 passes through a communication passage 51 and a communication hole 53 (described later) provided in the movable scroll 25 (see FIG. 7), and is sent to an oil groove 23D on the fixed scroll 23 side, and scroll compression is performed from the oil groove 23D. It is supplied to each sliding part of the mechanism 11 and the compression chamber 27 (see FIG. 3).

  The housing 21 is formed with a support portion 21A in which the eccentric shaft portion 15A of the drive shaft 15 rotates, and a radial bearing portion 21B extending downward from the center of the lower surface of the support portion 21A. Further, the housing 21 is provided with a radial bearing 21C penetrating between the lower end surface of the radial bearing portion 21B and the bottom surface of the support portion 21A. Further, near the outer peripheral edge portion on the lower surface side of the support portion 21A, a thin plate-like oil collector 24 that prevents the lubricating oil from entering a discharge pipe (not shown) extends along the inner peripheral surface of the casing body 5. Is suspended.

  The upper cap 7 of the casing 3 has a suction pipe (not shown) that guides the refrigerant in the refrigerant circuit to the scroll compression mechanism 11, and the casing body 5 has a discharge pipe that discharges the refrigerant in the casing 3 to the outside of the casing 3. It is fixed in a penetrating manner. The suction pipe extends vertically in the discharge space 29, and an inner end thereof passes through the fixed scroll 23 of the scroll compression mechanism 11 and communicates with the compression chamber 27, and the refrigerant is sucked into the compression chamber 27 by the suction pipe. The

  As shown in FIGS. 1 and 2, the fixed scroll 23 includes an end plate 23A, a spiral (involute) wrap 23B formed on the lower surface of the end plate 23A, and a spiral (involute) wrap 23B. A through hole 23 </ b> C is formed in the central portion so as to penetrate the end plate and open toward the discharge valve 22. In addition, the tip end surface (lower surface 233; see FIG. 4) of the wrap 23B on the refrigerant inlet side of the fixed scroll 23 facing the mirror surface 250 (see FIG. 1), which is the upper surface of the movable scroll 25, faces this. A narrow oil groove 23 </ b> D is formed on the lower surface 233.

  On the other hand, as shown in FIG. 3, the movable scroll 25 includes an end plate 25A, a spiral (involute) wrap 25B formed on the upper surface of the end plate 25A, and a spiral (involute) center of the wrap 25B. And a recess 25D that forms a dummy port that adjusts the timing at which the refrigerant gas in the compression chamber 27 in a high-pressure state is discharged toward the discharge space 29. The wrap 23B of the fixed scroll 23 and the wrap 25B of the movable scroll 25 are meshed with each other, and a plurality of compression chambers 27 are formed between the wraps 23B and 25B (see FIG. 1).

  As shown in FIG. 4, the movable scroll 25 has a flow restricting member (pin member) 55 inserted in a communication passage 51 described later. The pin member 55 includes a first pin 55A that fits in the lower hole 51A on the back side of the communication path 51, and a second pin that comes into contact with the first pin 55A and fits in the insertion hole 51B on the near side of the communication path 51. It is comprised by the pin 55B. A screw member with a hexagonal hole (not shown) is screwed into the female screw hole 51C so as to integrally press the second pin 55B and the first pin 55A toward the back end side, and the screw member is one end of the insertion hole 51B (FIG. 4). The left end is closed. Further, the screw member is fixed so as not to be loosened by an adhesive or the like.

  As shown in FIG. 1, the movable scroll 25 is supported by the fixed scroll 23 via the Oldham ring 61, and a bottomed cylindrical boss portion 25C projects from the center of the lower surface of the end plate 25A. On the other hand, an eccentric shaft portion 15A is provided at the upper end of the drive shaft 15, and the eccentric shaft portion 15A is rotatably fitted into a boss portion 25C of the movable scroll 25.

  As shown in FIG. 4, the movable scroll 25 is formed with a communication passage 51 formed in the end plate 25 </ b> A with one end opened to the outside and linearly extended to the inside. The communication path 51 forms a lower hole 51A of a communication path whose one end opens to the outside. The lower hole 51A is reamed from one end to a predetermined depth position to form an insertion hole 51B having a predetermined depth. A female screw hole 51C is screwed into the entrance of the insertion hole 51B. The other end (high pressure opening) 51 </ b> D of the communication path 51 communicates with the oil chamber (high pressure portion in the hermetic container) 52 on the back surface of the movable scroll 25 described above. In addition, a communication hole 53 having a perfect circle shape is opened on the inner peripheral surface on the entrance side of the communication path 51.

  The communication hole 53 is formed in the end portion of the movable scroll 25 near the inlet facing the low pressure portion 27A of the compression chamber so as to penetrate the mirror surface 250 in the thickness direction, and is opened so that the fixed scroll 23 faces. ing.

  Further, the drive shaft 15 below the radial bearing portion 21B of the housing 21 is provided with a counterweight portion 16 for dynamic balance with the movable scroll 25, the eccentric shaft portion 15A, and the like. By rotating the drive shaft 15 while balancing the weight, the movable scroll 25 is revolved without rotating. As the movable scroll 25 revolves, the compression chamber 27 is configured to compress the refrigerant sucked from the suction pipe when the volume between the wraps 23B and 25B contracts toward the center. .

  A through hole 23 </ b> C constituting a discharge port is provided in the central portion of the fixed scroll 23, and the gas refrigerant discharged from the through hole 23 </ b> C is discharged to the discharge space 29 through the discharge valve 22. And it flows out to the space outside the oil collector 24 in the high-pressure space 17 below the housing 21 through vertical grooves (not shown) provided on the outer peripheries of the housing 21 and the fixed scroll 23. This high-pressure refrigerant is finally discharged out of the casing 3 through a discharge pipe provided in the casing body 5.

  Next, the spiral tip (involute) tip Z of the wrap 23B of the fixed scroll 23, which is a characteristic configuration of the present invention, in other words, the apex of the convex curved surface S32 on the non-involute surface S3 described later. The shape in the vicinity of the point Z, that is, the shape of the portion facing the through hole 23C and the configuration of the through hole 23C will be described with reference to FIGS. 5 to 8 in particular.

  For example, in the end plate 23′A such as a general fixed scroll 23 ′ shown in FIG. 5 (B), a through hole 23 ′ in the vicinity of the tip Z ′ (see FIG. 5 (B)) of the wrap 23′B. It has been confirmed that the part that faces C in the closest state constitutes the maximum stress generation part during the operation of the scroll compressor by the analysis by FEM (finite element method). Incidentally, in the end plate 23A of the fixed scroll 23 shown in FIG. 5A, which is the present embodiment, the details will be described later, but the through hole 23C in the vicinity of the front end Z (see FIG. 5A) of the wrap 23B is the most. The physical strength of the part corresponding to the above that faces in the approaching state is greatly reinforced.

  In FIG. 8, reference numerals s <b> 1 and s <b> 2 denote an inner involute surface and an outer involute surface in the movable scroll 25, respectively. Reference numerals E1 and E2 denote a major axis length in the through hole 23C of the fixed scroll 23 and a minor axis length orthogonal to the major axis length, respectively. Furthermore, the symbols e1 and e2 respectively indicate the major axis length in the recess 25D of the movable scroll 25 and the orthogonal axis length orthogonal thereto.

  The wrap 23B is formed to have a height (h + Δh) that is higher than the height (h) described in the specification 1 of Table 1 to be described later, and can be configured to increase the output as a compressor. Has been. Further, as shown in FIG. 7, the front end portion Z of the wrap 23B is the starting point P of the inner side surface (hereinafter referred to as “inner involute surface S1”) of the two surfaces constituting the wrap 23B of the fixed scroll 23. And a non-involute surface S3 is formed in a region α (see FIG. 5A) between the start point Q of the outer surface (hereinafter referred to as “outer involute surface S2”) of the two surfaces. . The non-involute surface S3 is formed without changing the positions of both starting points of the inner involute surface S1 and the outer involute surface S2.

  The non-involute surface S3 is a curved portion region α (= α1 + α2) indicated by a line segment from point P → point R → point Z → point Q in FIG. 5A, and the point R is a non-involute surface. This corresponds to the point where the concave curved surface S31 and the convex curved surface S32 of the surface S3 intersect. That is, the region from the point P to the point R is a concave surface portion, and constitutes the concave curved surface S31 that is the inner non-involute surface of the non-involute surface S3. On the other hand, the region from point R through point Z to point Q is a convex surface portion and constitutes a convex curved surface S32 that is an outer non-involute surface of the non-involute surface S3. Note that the point Z corresponds to the vertex of the convex curved surface S32 that is the outer non-involute surface S3. Further, as described above, the point R is a starting point as a common non-involute surface for the concave curved surface S31 that is an inner non-involute surface and the convex curved surface S32 that is an outer non-involute surface.

  The non-involute surface S3 of the present invention has a curved surface shape with a small radius of curvature r (r <r ′; r ′ represents the entire concave surface S31, particularly from the start point R to the end point P of the concave surface S31; B), the radius of curvature of the inner involute surface S′1 in the fixed scroll of the specification 1 in Table 1 described later). That is, the concave curved surface S31 has a shape as shown by a solid line shifted in a direction closer to the through hole 23C (rightward in the figure) than the inner involute surface shown by a broken line in FIG.

On the other hand, for the convex curved surface S32 of the non-involute surface S3, that is, from the point R which is also the starting point on the convex curved surface S32 to the end point Q, a curved surface having an appropriate shape different from the inner involute surface, for example, the inner involute surface An arbitrary shape such as an arc-shaped curve shifted outward may be used. In the present embodiment, an arc having an appropriate curvature radius is used. Thus, as shown in Figure 8, the thickness T in the vicinity of the apex Z side of the convex surface S32 which is also the leading end portion of the lap 23B of the fixed scroll 23, the vicinity of the distal end portion Z ₀ side of the lap 25B of at least the movable scroll 25 It is thicker than the thickness T ₀ in.

Next, a method for forming a curved surface constituting the above-described non-involute surface S3 will be described.
(1) Desired Cartesian coordinates, that is, as shown in FIG. 7, an orthogonal XY coordinate is set at a predetermined position as an origin O, and a basic circle β is drawn at the origin O on the two-dimensional coordinates. The basic circle β is arbitrary for each of various compressors, and for example, the radius thereof is uniquely determined exclusively by the size of the fixed scroll and the output of the compressor.

  (2) When the basic circle β is determined at a predetermined position in this way, an involute curve (a curve indicated by a two-dot chain line in FIG. 5) having an involute function as a primitive function with the basic circle β as a reference. This is called a primitive involute curve), and this primitive involute curve is rotated in both directions by a fixed angle (that is, the involute start point angle δ) around the origin. As a result, two involute curves having a constant width t at the starting point R are obtained. These are the inner involute surface S1 and the outer involute surface S2 in the fixed scroll 23, but the constant region α is changed to a non-involute surface from the starting point R on the spiral center portion side as described later.

  (3) Next, in order to create an inner non-involute surface and an outer non-involute surface as shown in FIG. 7, which are uniquely determined by a required compression ratio, two straight lines having a constant angle θ are drawn. prepare. Then, using these straight lines, straight lines V and V ′ that are two tangent lines when contacting the basic circle β are determined. Here, the angle θ is for obtaining the involute start angle, and is uniquely determined by the compression ratio.

(4) Then, the intersection point P where the straight line V intersects the inner involute surface S1 and the intersection point Q where the straight line V 'intersects the outer involute surface S2 are determined.
The intersection point P is the end point of the inner non-involute surface (ie, the concave curved surface S31) and the start point of the inner involute surface S1, and the intersection point Q is the end point of the outer non-involute surface (ie, the convex curved surface S32) and the outer involute surface S2. This is the starting point. The point R, which is the starting point of the concave curved surface S31 that is the inner non-involute surface and the starting point of the convex curved surface S32 that is the outer non-involute surface, is a point where both curved surfaces intersect.

(5) Next, as shown in FIG. 5 (A), the curve in the α region indicated by the thick line connecting the four points including the two points P and Q, that is, the points P, R, Z, and Q, as shown in FIG. Is changed to a curved surface different from the involute, that is, the non-involute surface S3.
Of the non-involute surface S3 to be changed, the concave curved surface S31 to be the inner non-involute surface formed in the region α1 indicated by the two points P and R, as shown in FIG. An arc that is a part of the circumference drawn by a radius r centered on an arbitrary point C on the straight line V is formed, and the original involute shape is changed to this. Accordingly, the starting point of the inner involute surface S1 is changed to the point P. Note that the installation position of the center point of the circle when forming this arc is not necessarily limited to the section PN on the straight line V, which is a tangent line, and may be on an extension line thereof.

  (6) As a result, the involute curve formed in the region α1 in the region ahead of the starting point P on the already formed inner involute surface S1 is changed to an arc centered on the arbitrary point C described above. To do. In particular, the radius r of the circle in this case is smaller than the corresponding radius r ′ of the fixed roll 23 ′ of the specification 1 type (see Table 1 described later) shown in FIG. <R ′ is used. Thereby, the inner non-involute surface S31 formed in the region α1 is shifted slightly outward from the inner involute curved surface before being changed to this, that is, closer to the through hole 23C. In addition, about the circular arc curve here, what passes through both the points of the end point P and the start point R is used.

  (7) In the case of the present embodiment, the convex curved surface S32 that is the outer non-involute surface formed in the region α2 of the three points Q, Z, and R among the region α that forms the non-involute surface S3 is described above. As you can see, it has been changed to an arc curve. Thereby, it has shifted to the state which spreads a little outside rather than the outer involute curved surface before changing to this. As for the arc in this case, like the concave curved surface S31, in FIG. 7, two points of the contact point N ′ on the straight line V ′ that is the other side tangent to the basic circle β and the intersection point Q of the outer involute surface S2 described above. A part of the circumference drawn by a radius centered at an arbitrary point passing through N ′ and Q, which is the original involute shape, is changed to this.

  By using the wrap 23B of the fixed scroll 23 having the non-involute surface S3 thus formed, the strength of the fixed scroll 23 can be increased without changing the compression ratio.

  Next, the through hole 23C constituting the discharge port formed in the spiral center portion of the wrap 23B of the fixed scroll 23 will be described with reference to FIGS.

  In the present embodiment, the end plate at the point Z that is the tip of the wrap 23B of the fixed scroll 23, particularly the inner peripheral edge of the through hole 23C that forms the discharge port formed at the spiral central portion that is the tip of the wrap 23B of the fixed scroll 23. A fixed scroll that faces the inner peripheral edge of the through-hole 23C from the root portion of point 23A (directly below the portion indicated by point Z in FIG. 5A) and the root portion at point Z that is the tip of this wrap 23B. 23 is configured to ensure a long length (hereinafter referred to as “close-to-hole distance L”) between the closest closest edge portion U of 23.

  That is, in the normal general through-hole, for example, the fixed scroll 23 'shown in FIG. 5B, the base portion with respect to the end plate 23'A at the point Z' which is the tip of the wrap 23'B (FIG. 5B ) Immediately below the portion indicated by the point Z ') and the closest edge of the fixed scroll 23' that faces the inner periphery of the through hole 23'C from the root at the tip Z 'of the wrap 23'B. Compared to the length between U ′ (hereinafter referred to as “critical hole distance L ′”), at least the critical hole distance L of the present embodiment is longer, that is, L> L ′. It is comprised so that it may become.

  As described above, the critical hole distance L in the fixed scroll 23 can be increased as compared with the critical hole distance L ′ in the fixed scroll 23 ′ of the specification 1. This is because the size is smaller than the through hole 23 ′ C in the fixed scroll 23 ′ described in 1. The base surface 232, in particular, the critical distance L, can be secured longer in the end plate 23A by the smaller amount.

Therefore, in order to narrow down the through hole 23C, the present embodiment has the following configuration.
In the through hole 23C of the present embodiment shown in FIG. 5A, the size of the through hole 23′C opened in the fixed scroll 23 ′ corresponding to the specification 1 in Table 1 shown in FIG. The opening area is narrowed to about 80% to 90% (90% in this embodiment) (see FIGS. 5A and 5B). That is, the through hole 23C has an opening shape in the approach region (ε) facing the concave curved surface S31 of the non-involute surface S3, and the opening shape in the approach region (ε ′) in the through hole 23′C of the fixed scroll 23 ′. Compared with the opening shape, the opening is configured to be narrowed. For example, in the present embodiment, the critical hole distance L is increased by reducing the opening area by about 10%.

  Specifically, the opening radius of the through hole 23C is smaller than the radius of curvature r of the concave curved surface S31 so that the opening in the approach region (ε) facing the concave curved surface S31 (see FIG. 5A) is narrowed. It is composed of a curved surface that forms the inner edge. That is, the opening edge in the approach region (ε) is shifted and moved backward so as to approach toward the center direction of the through hole 23C (in FIG. 7, a portion indicated by a thick line from a portion indicated by a one-dot chain line). To the right). Thereby, the hole is narrowed to reduce the opening area. The curved surface of this portion may be, for example, an arc having a radius of curvature smaller than the radius of curvature r of the concave curved surface S31.

  In addition, about the opening shape of this through-hole 23C, as mentioned above, the inner edge part in the approach area | region ((epsilon)) which faces the concave curved surface S31 of the non-involute surface S3 of the fixed scroll 23 approaches the hole center direction. In the remaining area (λ) opposite to the approach area (ε) shown in FIG. 5A, the shape of the fixed scroll 23 ′ described in the specification 1 at the through-hole 23′C is narrowed by retreating. It is the same as and has not been changed. That is, the communication of the compression chamber starts from the remaining area (λ) on the side opposite to the wrapping side of the through hole 23C, but there is no change in shape on this side, so that the discharge timings of the two pairs of compression chambers are the same as before Are still the same.

Further, with regard to the relationship of the near hole distance L as described above, even when it is cut along an arrow cutting line VIA-VIA in FIG. 5 (A) that is slightly away from the vicinity of the point Z that is the tip of the lap 23B of the fixed scroll 23. It is the same.
That is, as shown in FIG. 6A, the fixed scroll according to the specification 1 of Table 1 is also used for the critical distance ΔL between the lap 23B and the through hole 23C at a portion slightly away from the vicinity of the tip Z of the lap 23B. The size is larger than the critical hole distance ΔL ′ in the normal fixed scroll 23 ′ shown in FIG. 6B, which is a cross-sectional view taken along the corresponding portion 23 ′.

  Thus, as in the case of the critical hole distance L described above, the increase of the critical hole distance ΔL can be realized because the through hole 23C of the fixed scroll 23 at the cut surface portion as shown in FIG. This is made possible by making the width W narrower than the width W ′ (where W <W ′) of the corresponding portion of the through hole 23′C in the fixed scroll 23 ′.

  Moreover, as shown in FIG. 6 (A), the through hole 23C constituting the discharge port formed in the spiral center portion that is the apex Z that is also the distal end portion of the wrap 23B of the fixed scroll 23 of the present embodiment. In the inner peripheral surface of the fixed scroll 23, the height H of the vertical wall 231 that rises vertically from the base surface 232, which is the surface portion connected to the base of the wrap 23B, of the mirror surface 230 of the end plate 23A of the fixed scroll 23 is increased. It has a formed configuration.

  In particular, with respect to the through hole 23C of the present embodiment, as shown in FIGS. 5A and 6A, the wrap width t (see FIG. 5A) in the portion of the fixed scroll 23 excluding the lap 23B tip Z. The vertical wall 231 is provided so that the height H is about twice as high as that of (see (2)), that is, H = 2t.

  On the other hand, as shown in FIG. 5 (B) and FIG. 6 (B), the fixed scroll 23 ′ of the specification 1 generally has a portion excluding the tip of the wrap 23′B of the fixed scroll 23 ′. The vertical wall 231 'is provided from the base surface 232' so that the height H 'is substantially the same as the width t' at H, that is, H'≈t '.

  Accordingly, the through-hole 23C of the present embodiment has a vertical wall 231 formed higher than a normal general through-hole, that is, the through-hole 23′C in the fixed scroll 23 ′ of the specification 1, and therefore the wrap 23B. The end plate has a structure in which the thickness of the end plate 23A in the vicinity of the point Z is substantially increased, and the strength is greatly increased structurally.

Next, the relationship between the through hole 23C of the fixed scroll 23 and the recess 25D of the movable scroll 25 will be described with reference to FIG.
The through hole 23C of the present embodiment is smaller than the size of the recess 25D constituting the dummy port formed in the spiral center portion of the wrap 25B of the movable scroll 25, that is,
E1 <e1 and E2 <e2
It is formed to satisfy. Thus, the through hole 23C is not the same area as the depression 25D, but has a smaller area.

  Further, the through-hole 23C of the fixed scroll 23 and the recess 25D of the movable scroll 25 are assembled in a relative positional relationship in which the phases are shifted 180 degrees from each other and reversed point-symmetrically. Here, according to elementary geometry, as is well known, “point symmetry” defines the relationship between figures that overlap each other when rotated 180 degrees around the center position of symmetry. In the embodiment, it is described as “point-symmetric” in consideration of the fact that the shapes are similar and the sizes are different so that they do not overlap exactly.

  By forming the through hole 23C in such a shape, the communication between the compression chambers starts from the remaining region (λ; see FIG. 5) on the opposite side of the through hole 23C, so the discharge timing of the two pairs of compression chambers Are still the same. As a result, it is possible to effectively avoid the occurrence of an unnecessarily large load with respect to the bearing load. As a result, it is possible to prevent an adverse effect on noise, vibration, durability and the like from being generated.

Next, the operation of the scroll compressor 1 will be described.
When the drive motor 13 is driven, the rotor 13B rotates with respect to the stator 13A, and thereby the drive shaft 15 rotates. When the drive shaft 15 rotates, the movable scroll 25 of the scroll compression mechanism 11 keeps its posture with respect to the fixed scroll 23 and does not rotate but only revolves. As a result, the low-pressure refrigerant is sucked into the compression chamber 27 from the peripheral side of the compression chamber 27 through the suction pipe, and is compressed as the volume of the compression chamber 27 changes.

  The compressed refrigerant becomes high pressure and is discharged from the compression chamber 27 through the discharge valve 22 to the discharge space 29, and through the vertical grooves (not shown) provided on the outer circumferences of the housing 21 and the fixed scroll 23. Flows out of the oil collector 24 on the high-pressure space 17 side below. The high-pressure refrigerant is discharged out of the casing 3 through a discharge pipe (not shown) provided in the casing body 5. The refrigerant discharged to the outside of the casing 3 circulates through a refrigerant circuit (not shown), is again sucked into the compressor 1 through the suction pipe, is compressed, and the circulation of the refrigerant is repeated.

Next, the flow of the lubricating oil will be described.
The lubricating oil stored in the inner bottom portion of the lower cap 9 in the casing 3 is scraped up by a pickup (not shown) provided at the lower end of the drive shaft 15 shown in FIG. 1, and this lubricating oil is supplied to the oil supply passage 15B of the drive shaft 15. Then, the oil is supplied to the oil chamber 52 in the high pressure state on the back of the movable scroll 25. Further, the lubricating oil opens from the oil chamber 52 shown in FIG. 4 to the lower surface 233 which is the front end surface of the lap 23B on the fixed scroll 23 side through the communication passage 51 and the communication hole 53 provided in the movable scroll 25. The oil groove 23 </ b> D (see FIGS. 2 and 4) is fed out using the differential pressure and supplied to the sliding portions of the scroll compression mechanism 11 and the compression chamber 27.

  Further, for example, in FIG. 1, when the oil supplied to the compression chamber 27 moves to the center of both scrolls, which is a high-pressure compression chamber, the discharge valve 22 is caused to flow along with the flow of the refrigerant in the high-pressure state compressed here. It is discharged to the discharge space 29 through. Thus, the lubricating oil discharged into the discharge space 29 through the discharge valve 22 together with the high-pressure refrigerant passes through the vertical grooves (not shown) provided on the outer peripheries of the housing 21 and the fixed scroll 23. Flows out into the high-pressure space 17 below. The oil is stored in the inner bottom of the lower cap 9 corresponding to the lower space 91 through the inner wall of the casing body 5 and the gap of the drive motor 13. In this case, the high-pressure space 17 has a thin plate shape. Since the oil collector 24, the cup 26, and the like are installed, the oil can be recovered to the inner bottom portion of the lower cap 9 while preventing entry into the discharge pipe.

  Next, when the five types of scroll compressors provided with various types of fixed scrolls including the fixed scroll 23 according to the present embodiment are operated, the closest state to the through hole near the tip of the wrap described above An experiment was conducted to investigate the maximum stress that acts on the part facing the surface. The effect of this embodiment is demonstrated referring [Table 1] which shows the result. Here, among the fixed scrolls shown in the specifications 1 to 6, the specification 1 is usually a general low output type, and the specification 2 is a general high output type. . The specification 5 shows the fixed scroll 23 used in the present embodiment.

  As can be seen from Table 1 above, the specification 5 corresponding to the fixed scroll of this embodiment has a scroll tooth height of Δh compared to the specification 1 (low output type) which is a general configuration. The discharge hole area is reduced by a factor of 0.9 and the vertical wall of the discharge hole is increased by a factor of 2.5. The knowledge that the force acting on the root of the tip Z where the maximum stress of the fixed scroll was generated can be reduced by 28% by adopting such a configuration. Therefore, according to the compressor 1 of this embodiment provided with the fixed scroll shown in the specification 5, it was confirmed that the strength of the end plate 23A in the vicinity of the root Z of the wrap 23B tip Z of the fixed scroll 23 was increased.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible in the range which does not deviate from the summary as described in a claim. For example, the fixed scroll of the present invention is not limited to the specification 5 in Table 1 above, and may have any of the specifications 3, 4 and 6.

DESCRIPTION OF SYMBOLS 1 Scroll type compressor 11 Scroll compression mechanism 13 Drive motor 13A Stator 13B Rotor 15 Drive shaft 15A Eccentric shaft part 15B Oil supply path 16 Counterweight part 17 High pressure space 21 Housing 21A Support part 21B Radial bearing part 22 Discharge valve 23 Fixed scroll 23A End plate 23B Wrap 23C Through hole (discharge port)
23D Oil groove 230, 250 Mirror surface 231 Vertical wall 232 Base surface 24 Oil collector 25 Movable scroll 25A End plate 25C Boss part 25D Dimple (dummy port)
27 Compression chamber 27A Low pressure part 29 Discharge space 3 Casing 5 Casing body 51 Communication path 51A Lower hole 51B Insertion hole 51C Female thread hole 52 Oil chamber (High pressure part in the sealed container)
53 Communication hole 55 Flow rate restricting member (pin member)
55A 1st pin 55B 2nd pin 61 Oldham ring 7 Upper cap 9 Lower cap 91 Lower space H Vertical wall height L, ΔL Near hole distance N Contact point (intersection of base circle and straight line)
P Start point of inner involute surface (end point of inner non-involute surface)
Q Starting point of outer involute surface (end point of outer non-involute surface)
R The point where the concave surface of the non-involute surface and the convex surface meet (the starting point of both)
r Curvature radius of non-involute surface S1 Inner involute surface S2 Outer involute surface S3 Non-involute surface S31 Concave surface on non-involute surface (inner non-involute surface)
S32 Convex curved surface on non-involute surface (outer non-involute surface)
T Thickness of the fixed scroll lap tip side T ₀ Thickness of the movable scroll wrap tip side t Wrap width U of the portion other than the fixed scroll wrap tip portion U (facing the root of the fixed scroll wrap tip portion) Nearest edge V, V 'straight line (tangent to base circle)
Z Fixed scroll wrap tip (vertex of convex surface of non-involute surface)
z Moveable scroll wrap tip (vertex of convex surface of non-involute surface in specification 1)
α Formation region of non-involute surface β Fundamental circle ε Approach region facing fixed curved surface of non-involute surface of fixed scroll

Claims (2)

A fixed scroll fixed inside the casing and a movable scroll meshing with the fixed scroll, and between a spiral wrap formed on the end plate of the fixed scroll and a spiral wrap formed on the end plate of the movable scroll A compression chamber is formed , and includes a through-hole constituting a discharge port formed through the end plate in a spiral central portion of the fixed scroll wrap ,
The scroll-type compressor in which a part of the side wall of the through-hole forms a vertical wall that is displaced inward from the portion of the peripheral edge of the through-hole connected to the root of the wrap tip of the fixed scroll. In
The vertical wall is formed so that its height is approximately twice the thickness of the portion of the fixed scroll that faces the intermediate pressure chamber excluding the wrap tip of the fixed scroll ,
An inner non-involute surface that is a concave curved surface and an outer non-involute surface that is a convex curved surface that forms the tip of the wrap between the starting point of the inner involute surface and the starting point of the outer involute surface constituting the wrap of the fixed scroll The non-involute surface is formed by shifting the inner non-involute surface, which is the concave curved surface, closer to the through hole due to a curved surface shape having a smaller radius of curvature than the case of forming the involute surface. The through hole is formed so that the opening shape in the approaching area facing the inner non-involute surface that is the concave curved surface is a curved surface that is smaller than the radius of curvature of the inner non-involute surface that is the concave curved surface, and the opening area is small. A scroll compressor characterized by being formed . The movable scroll is provided with a dent constituting a dummy port at a spiral central portion which is a wrap tip portion in an arrangement state in which at least a part of the scroll is at least partially overlapped with the through-hole of the fixed scroll when viewed in the axial direction. The size of the through-hole is formed larger than the size of the through-hole, and the through-hole of the fixed scroll and the recess of the movable scroll have a similar shape and are reversed in a point-symmetric manner with a phase difference of 180 degrees from each other. Formed in a relative positional relationship ,
The scroll compressor according to claim 1 .

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