JP2001055989A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a scroll compressor while preventing the cracking and breakage of a joint portion (the root of a spiral wall) on the spiral center side and decreasing efficiency of the compressor. SOLUTION: The radius (r) of curvature of a joint portion 12a between a spiral wall 12 and a base 11 is made constant over the whole periphery in the spiral direction and an angular portion 12b of the spiral wall 12, corresponding to the, joint portion 12a, is formed in an approximately circular shape. Therefore, no recombination of an end mill is required over the whole periphery in the spiral direction and machining work is done by one end mill, resulting in a less number of manufacturing processes. As a rounded portion 12c is formed on the angular portion 12b, a gap δ formed between the angular portion 12b and the joint 12a can be smaller. The manufacturing cost can be reduced, accordingly, while preventing the cracking and breakage of the joint 12a on the spiral center side and the decreasing efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor, and is effective when applied to a compressor of a vapor compression refrigeration cycle.

[0002]

2. Description of the Related Art As is well known, scroll type compressors are known in the art.
By scrolling one scroll (orbiting school) with respect to the other scroll (fixed scroll) among a pair (two) of scrolls composed of a spiral-shaped spiral wall and a base provided with the spiral wall, The volume of the working chamber formed by the two scrolls is enlarged or reduced to suck and compress a fluid such as a refrigerant.

At this time, the volume of the working chamber of the scroll compressor is reduced while moving from the outer side of the spiral to the center of the spiral with the turning of the orbiting scroll.
The internal pressure of the working chamber located at the center of the spiral is the highest. In addition, since the stress is easily concentrated at the joint between the spiral wall and the base (the root of the spiral wall), the joint between the spiral wall and the base at the center of the spiral is compared with other parts (joint). Therefore, problems such as crack breakage are likely to occur.

Therefore, generally, as shown in FIG.
By making the shape of the connecting portion 12a an arc shape (by forming an R portion) to alleviate stress concentration and chamfering a corner 12b corresponding to the connecting portion 12a on the tip side of the spiral wall 12, the spiral wall is formed. 12 and the connecting portion 1
2a is prevented.

[0005]

In order to reduce stress concentration, it is desirable to increase the radius of curvature r (root r) of the connecting portion (R portion) 12a as much as possible.
Is increased, the chamfering length L of the tip corner 12b must be increased accordingly, and the gap δ generated between the tip corner 12b and the connecting portion 12a increases, and this gap δ There is a problem that the amount of fluid leaking from the compressor increases, and the efficiency (performance) of the scroll compressor is reduced.

To solve this problem, for example, Japanese Patent Application Laid-Open
As described in Japanese Patent No. 68392, R is applied only to the center of the spiral.
Part is formed, and no R part is formed in other parts or R part is formed.
It is known to make the radius of curvature r of the part smaller than that of the center of the spiral. However, in this means, the radius of curvature differs depending on the part of the spiral wall. It is necessary to change tools (tools, cutters). Therefore, with this means, the number of man-hours (manufacturing time) of the scroll increases, and it is difficult to reduce the manufacturing cost.

[0007] Further, since it is necessary to position the machining tool with respect to the scroll (work) being machined every time the machining tool is changed, the number of manufacturing steps is further increased, and the product (scroller) due to variation in the positioning accuracy is required. ) There is also a risk of inducing dimensional variations.

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to reduce the manufacturing cost while preventing a breakage of a joint at the center of a spiral and a decrease in compressor efficiency.

[0009]

According to the present invention, in order to achieve the above object, according to the first aspect of the present invention, a connecting portion between both spiral walls (122, 132) and both bases (121, 131) is provided. (12a) is formed in an arc shape,
The radius of curvature (r) of the connecting portion (12a) is constant over the entire circumference of the spiral walls (122, 132) in the vortex direction.
Furthermore, the corner (12b) corresponding to the joint (12a) on the tip side of both spiral walls (122, 132) is formed in an arc shape substantially similar to the joint (12a). Features.

[0010] Thus, without changing the machining tools from the center of the spiral to the outer periphery of the spiral over the entire circumference in the spiral direction,
Since it is possible to perform machining with one machining tool, it is possible to reduce the number of manufacturing steps for both scrolls (120, 130) and to prevent the occurrence of variations in product (scroll) dimensions due to the change of machining tools. it can.

The corner (12b) corresponding to the connecting portion (12a) is formed to have an arc shape substantially similar to the connecting portion (12a), so that the radius of curvature of the connecting portion (12a) ( Even if r) is increased, the corner (12b) and the connecting portion (12
a) can be reduced.

As described above, according to the present invention, the manufacturing cost of the scroll compressor can be reduced while preventing the breakage of the joint (12a) at the center of the spiral and the decrease in the efficiency of the scroll compressor. Can be planned.

According to the second and third aspects of the present invention, the connecting portion (12a) between the spiral wall (12) and the base (11) is formed in an arc shape and the radius of curvature of the connecting portion (12a). (R) is constant over the entire circumference of the spiral wall (12) in the spiral direction. Further, a corner (12b) on the tip side of the spiral wall (12) and corresponding to the joint (12a) is , And is formed in an arc shape substantially similar to the connecting portion (12a).

As a result, similarly to the first aspect of the present invention, the joint portion (12a) at the center of the spiral has cracks,
In addition, the manufacturing cost of the scroll compressor can be reduced while preventing the efficiency of the scroll compressor from decreasing.

In the present invention, at least the radius of curvature (r) of the connecting portion (12a) of the scroll on one side only needs to be constant over the entire circumference of the spiral.

According to the third aspect of the present invention, the dimension (a) from the spiral wall (12) to the connecting portion (11a) between the connecting portion (12a) and the base (11) has a radius of curvature (r). )
Is desirably larger than 1/2.

By the way, the reference numerals in parentheses of the above-mentioned means are examples showing the correspondence with the concrete means described in the embodiments described later.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment)
FIG. 1 is an axial cross-sectional view of a compressor 100 according to the present embodiment in which a scroll compressor (hereinafter, referred to as a compressor) according to the present invention is applied to a vehicle refrigeration cycle.

In FIG. 1, 111 is a front housing, and 112 is fixed to the front housing.
It is a shell that constitutes a space in which a later-described orbiting scroll 130 can orbit. The fixed-side base 121 integrally formed with the shell 112 has a spiral fixed-side spiral wall 1.
A fixed scroll 120 is formed by the fixed scroll wall 122 and the fixed base 121.

Reference numeral 131 denotes a swivel-side base formed integrally with a swirl-shaped swirl-side spiral wall 132 that comes into contact with the fixed swirl-wall 122, and is fixed by the swirl-side base 131 and the swirl-side spiral wall 132. An orbiting scroll 130 that orbits with respect to the scroll 120 is configured. Hereinafter, the spiral walls 122 and 132 are collectively referred to as a spiral wall 12 and the bases 121 and 131 are collectively referred to as a base 11.

As shown in FIG. 2, a connecting portion (a root portion of the spiral wall 12) 12a for connecting the spiral wall 12 and the base 11 is formed in an arc shape, and is connected to the arc shape. The radius of curvature r of the (R portion) 12a is formed to be constant from the spiral center side of the spiral wall 12 to the spiral outer periphery over the entire circumference in the spiral direction. Incidentally, the spiral wall 12, the base 11, and the connecting portion 12a are finished by cutting such as end milling.

Here, the radius of curvature r of the connecting portion 12a reduces the concentration of stress generated at the center of the spiral in the connecting portion 12a between the spiral wall 12 and the base 11, and the connecting portion 12a has a problem such as crack breakage. This is a size that does not cause the occurrence of.

On the other hand, a corner portion 12b corresponding to the connecting portion 12a on the distal end side of the spiral wall 12 has a rounded portion 12c having an arc shape substantially similar to the connecting portion 12a as shown in FIG. The rounded portion 12c has a constant radius of curvature R over the entire circumference in the vortex direction, similarly to the connecting portion 12a.
It is formed with. The radius of curvature R of the rounded portion 12c
Is larger than the radius of curvature r of the connecting portion 12a (R> r).

In FIG. 1, reference numeral 140 designates a shaft for turning the orbiting scroll 130 by obtaining a driving force from an external driving source (not shown) such as a vehicle running engine. An eccentric portion (crank portion) 141 formed at a portion eccentric from the rotation center of the end of the orbiting scroll 130 on the side of the orbiting scroll 130 has a bearing 14.
2 are connected.

Incidentally, in the present embodiment, the movable school 130 is provided between the eccentric part 141 and the bearing 142.
A bushing 143 which can be slightly displaced with respect to 41 is provided, and the orbiting scroll 130 is slightly displaced in the radial direction of the bushing 143 through the bushing 143 due to its centrifugal force, compression reaction force or the like. The contact surface pressure between the spiral walls 122 and 132 is increased.

Reference numeral 150 denotes an anti-rotation mechanism for preventing the orbiting scroll 130 from rotating (rotating) around the eccentric portion 141 when the shaft 140 rotates and the orbiting scroll 130 orbits. 150
Is composed of a pin 151 press-fitted into the turning-side base 131 and the front housing 111 and a ring 152 into which both pins 151 are inserted. Therefore, the shaft 1
When the rotation of the rotary shaft 40 is completed, the orbiting scroll 130 rotates the shaft 1.
Instead of rotating with the rotation of the shaft 40, the shaft 40 rotates (revolves) around the shaft 140.

By the way, as shown in FIG. 4, the spiral walls 122 and 132 form a working chamber (compression chamber) P in which a fluid (a refrigerant in this embodiment) is confined by contacting at a plurality of locations. The working chamber P formed on the outer side of the spiral moves from the outer side of the spiral to the middle of the spiral with the turning of the orbiting scroll 130, and reduces the volume thereof to compress the refrigerant. The orbiting scroll 130 is orbitable in the order of FIG. 4 (a) → FIG. 4 (b) → FIG. 4 (c) → FIG. 4 (d) → FIG. 4 (a).

In FIG. 1, reference numeral 123 denotes a discharge port for discharging the fluid compressed in the working chamber P. This discharge port 123 is a discharge chamber for smoothing the pulsation of the fluid discharged from the discharge port 123. And 113. And
The discharge chamber 113 includes a fixed base 121 (shell 112) and a rear housing 114.

Reference numeral 124 denotes a reed valve-shaped discharge valve for preventing a fluid from flowing backward from the discharge chamber 113 to the working chamber P.
Reference numeral 125 denotes a stopper (valve stop plate) for regulating the maximum opening of the discharge valve 124. 144 is a bearing that rotatably supports the shaft 140, and 145 is a lip seal that prevents fluid from leaking out of the compressor 100.

Next, the features of this embodiment will be described.

According to the present embodiment, the spiral wall 12 and the base 1
Since the radius of curvature r of the connecting portion 12a that connects the spiral 1 to the spiral is formed from the center of the spiral to the outer periphery of the spiral over the entire circumference in the spiral direction, the direction of the spiral changes from the center of the spiral to the outer periphery of the spiral. A single end mill can be used without changing the end mill (machining tool) over the entire circumference. Therefore, it is possible to reduce the number of manufacturing steps of the scrolls 120 and 130 and to prevent a product (scroll) size variation due to an end mill assembling operation.

Further, a rounded portion 12c is formed at the corner 12b on the tip end side of the spiral wall 12 and corresponding to the connecting portion 12a so as to have an arc shape substantially similar to the connecting portion 12a. Even if the radius of curvature r of the connecting portion 12a is increased,
Compared to the chamfered corner 12b, the corner 12b
The gap δ generated between the connecting portion 12a and the connecting portion 12a can be reduced.

The dashed line in FIG. 3 shows the case where chamfering is performed. As is clear from this figure, if the rounded portion 12c is formed, the corner 12b is more chamfered. Since the end of the corner 12b is closer to the joint 12a, the gap δ can be reduced.

As described above, according to the present embodiment, the manufacturing cost of the compressor 100 can be reduced while preventing the breakage of the connecting portion 12a at the center of the spiral and the decrease in efficiency of the compressor 100. Can be.

Incidentally, since the rounded portion 12c of the corner 12b is performed by a special tool (special blade), the man-hour for forming the rounded portion 12c on the corner 12b and the man-hour for chamfering the corner 12b are reduced. Does not change.

(Second Embodiment) In the first embodiment, the connecting portion 12a is formed such that the length Lo of the arc portion is π / 2 of the radius of curvature r.
(= 2πr / 4) times (the arc portion and the wall surface of the spiral wall 12 and the base 11 are completely connected), but this embodiment is, as shown in FIG. This is an incomplete R portion in which the length Lo of the arc portion is less than rπ / 2.

If the length Lo of the arc portion is excessively small, the substantial radius of curvature r is reduced even if the radius of curvature r is increased, and stress concentration tends to occur at the joint 12a. Therefore, in the present embodiment, the dimension a from the spiral wall 12 to the connecting portion 11a between the connecting portion 12a and the base 11 is set to be larger than 1/2 of the radius of curvature r.

(Other Embodiments) In the above-described embodiment, the connecting portion 12a of both scrolls is formed in an arc shape so as to have the same radius of curvature r over the entire circumference of the spiral. At least, the radius of curvature r of the connecting portion 12a of the scroll on one side only needs to be constant over the entire circumference of the spiral.

Further, the application of the compressor according to the present invention is not limited to a vehicle air conditioner, but may be applied to other types.

In the above embodiment, the discharge chamber 113
Does not have an oil separator (oil separator) for separating the lubricating oil (refrigeration oil) mixed in the refrigerant into the refrigerant, but the present invention can also be applied to a compressor having an oil separator. .

Before the lubricating oil separated by the oil separator is sent to the sliding portions of the scrolls 120 and 130, an oil filter for removing dust in the lubricating oil may be provided.

[Brief description of the drawings]

FIG. 1 is an axial sectional view of a scroll compressor according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a root portion of a spiral wall.

FIG. 3 is an enlarged view of a portion A in FIG. 1;

FIG. 4 is an explanatory view showing the operation of the orbiting scroll.

FIG. 5 is an enlarged view of a root portion of a spiral wall in the scroll compressor according to the first embodiment of the present invention.

FIG. 6 is an enlarged view of a root portion of a spiral wall in a scroll compressor according to the related art.

[Explanation of reference numerals] 11: base, 12: spiral wall, 12a: connecting part, 12b ...
Corner, 12c: rounded, 120: fixed scroll, 12
DESCRIPTION OF SYMBOLS 1 ... Fixed side base, 122 ... Fixed side spiral part, 130 ... Revolving scroll, 131 ... Revolving side base, 132 ... Revolving side spiral part, delta ... Gap.

Continued on the front page (72) Inventor Takeshi Takemoto 1-1-1, Showa-cho, Kariya-shi, Aichi Pref. ) Inventor Kimihiko Sato 1-1-1, Showa-cho, Kariya-shi, Aichi F-term in DENSO Corporation (Reference) 3H039 AA02 AA12 BB05 BB07 CC02 CC03 CC05

Claims (3)

[Claims] 1. A scroll type compressor for sucking and compressing a fluid, comprising: a housing (111, 112, 114); and a spiral fixed-side spiral wall fixed to the housing (111, 112, 114). (122) and a fixed-side base (12) provided with the fixed-side spiral wall (122).
1), a fixed scroll (120), a revolving scroll wall (132), which meshes with the fixed revolving wall (122), and the revolving scroll wall (13).
The orbiting scroll (1) having an orbiting side base (131) provided with 2) and forming a working chamber (P) for sucking and compressing a fluid while rotating with respect to the fixed scroll (120).
30), and the two spiral walls (122, 132) and the two bases (12
1, 131) is formed in an arc shape, and the radius of curvature (r) of the connecting portion (12a) is set to be equal to the entire circumference of the spiral wall (122, 132) in the vortex direction. And a corner (12b) corresponding to the connecting portion (12a) on the tip side of the spiral walls (122, 132).
Is formed in a circular arc shape substantially similar to the connecting portion (12a). 2. A pair of scrolls (120, 130) having a spiral-shaped spiral wall (12) and a base (11) provided with the spiral wall (12), wherein one scroll (130) is the other. A scroll type compressor that sucks and compresses a fluid by turning with respect to a scroll (120) on the side of the scroll (120), wherein a connection portion (1) between the spiral wall (12) and the base (11) is provided.
2a) is formed in an arc shape, and the radius of curvature (r) of the connecting portion (12a) is the same as that of the spiral wall (12).
Further, a corner (12b) corresponding to the connecting portion (12a) on the distal end side of the spiral wall (12) is fixed to the connecting portion (12a). A scroll compressor having a substantially similar arc shape. 3. The connecting portion (1) from the spiral wall (12).
The scroll type compressor according to claim 2, wherein a dimension (a) up to a connecting portion (11a) of the base (11) and the base (11) is larger than 1/2 of the radius of curvature (r). .