JP4752812B2 - Pressure vessel - Google Patents

Description

  The present invention relates to a pressure vessel having a compression mechanism portion therein, for example.

  As a conventional pressure vessel, for example, a container used in a hermetic compressor as shown in Patent Document 1 is known. The pressure vessel is formed by welding and joining a cylindrical body, and a bottomed cylindrical upper and lower end panels, and the rigidity of the body is set to be greater than the rigidity of both end panels. ing. For example, the thickness of the body portion is set to be thicker than the thickness of both end plates.

As a result, when internal pressure is applied, the difference in deformation between the barrel and the end plate near the weld joint is reduced, the tear load acting on the weld joint is reduced, and the pressure resistance as a pressure vessel is increased. I try to improve.
JP 2002-336472 A

  However, by increasing the thickness of the body part, there is a problem that the physique increases and the weight also increases.

  In view of the above problems, an object of the present invention is to provide a pressure resistant container capable of improving the pressure strength without increasing the physique and weight.

  In order to achieve the above object, the present invention employs the following technical means.

  According to the first aspect of the present invention, a cylindrical main body housing (111) and end housings (112, 113) for closing end openings of the main body housing (111) are provided, and a predetermined device (130) is provided therein. ) And the end housing (112, 113) is formed in a cylindrical shape and welded with an overlap to the end of the main body housing (111) in a pressure resistant container to which a predetermined internal pressure (Ps) is applied. A joint portion (113a) to be formed, an end portion formation portion (113b) that forms a closing surface of the end opening, and a joint portion (113c) that connects the joint portion (113a) and the end portion formation portion (113b). And at least part of the end portion forming portion (113b) and the connecting portion (113c) is characterized in that a portion having a thickness smaller than that of the joint portion (113a) is formed.

  In the pressure vessel (110), a predetermined internal pressure (Ps) acts on the inside thereof, so that the main body housing (111) is deformed into a drum shape. Further, the end portion forming portion (113b) of the end housing (112, 113) is deformed so as to bulge outward, and the joint portion (113a) is potted inward via the connecting portion (113c) along with the deformation. Deforms like a circle. Therefore, the site | part which is not welded in the overlap margin of a main body housing (111) and a junction part (113a) spreads away from each other, and stress concentrates on a welding part (114).

  In the first aspect of the present invention, at least a part of the end portion forming portion (113b) and the connecting portion (113c) is formed with a portion where the plate thickness is thinner than the joint portion (113a). When the end housings (112, 113) are to be deformed by the predetermined internal pressure (Ps), the deformation can be absorbed by the thin-walled portion and the deformation to the joint portion (113a) can be suppressed. Stress concentration on (114) can be suppressed. Therefore, the pressure strength of the pressure vessel (110) can be improved without increasing the physique and weight.

  The invention according to claim 2 is characterized in that the portion where the plate thickness is reduced is formed in the connecting portion (113c).

  Thereby, the connecting portion (113c) is deformed by the predetermined internal pressure (Ps), and the deformation to the joint portion (113a) can be effectively absorbed, so that the pressure-resistant strength of the pressure-resistant container (110) is improved. Can do.

  In addition, it is only necessary to form the thin portion of the joining portion (113a), the end portion forming portion (113b), and the connecting portion (113c) only in the region of the connecting portion (113c), so that it is not necessary to make the whole thin. , Can improve the ease of making.

  The invention according to claim 3 is characterized in that the portion where the plate thickness is reduced is formed in the entire end portion forming portion (113b) and connecting portion (113c).

  As a result, the end portion forming portion (113b) and the connecting portion (113c) are entirely deformed by the predetermined internal pressure (Ps), and the deformation to the joint portion (113a) can be absorbed more effectively. Furthermore, the pressure strength of the pressure vessel (110) can be improved.

  As in the fourth aspect of the invention, the predetermined device (130) can be a compression mechanism (130) that compresses and discharges the working fluid.

  As a result, the compressor (100) with high pressure resistance can be configured in a small size, and since the pressure vessel (110) with low distortion, a reliable compressor with less distortion of the compression mechanism section (130) can be configured.

  Further, when the working fluid of the compression mechanism section (130) is carbon dioxide as in the invention described in claim 5, the predetermined internal pressure used is very high, so that the pressure vessel (110) This is particularly suitable for reducing the size and weight.

  In addition, the cylindrical joint part (113a) means the cylindrical part close to the joint part with the main body housing (111).

  Moreover, the code | symbol in the parenthesis attached | subjected to each said means is an example which shows a corresponding relationship with the specific means as described in embodiment mentioned later.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. 1 is a cross-sectional view showing a schematic structure of an electric compressor 100 using a housing 110 as a pressure vessel in the first embodiment, FIG. 2 is a cross-sectional view showing a deformation state of the housing 110 due to an internal pressure Ps, and FIG. It is an enlarged view which shows the III part inside.

As shown in FIG. 1, the electric compressor 100 is applied to a refrigeration cycle apparatus (not shown) using carbon dioxide (CO ₂ ) as a refrigerant (working fluid), and has a motor unit 120 incorporated therein. Thus, the compressor mechanism (predetermined device) 130 is driven to compress and discharge the refrigerant to a pressure exceeding the critical pressure.

  The electric compressor 100 according to the present embodiment is placed in the posture shown in FIG. 1, and the so-called horizontal direction in which the extending direction (the X direction in the drawing) of the rotation axis 120 a of the motor unit 120 that rotates is the horizontal direction. It is a stationary electric compressor.

  However, the direction of the rotation axis 120a does not need to be strictly horizontal, and the fluid flowing through the electric compressor 100 behaves substantially the same when it behaves under the influence of gravity. If it is, it may be slightly inclined from the horizontal direction. That is, the extending direction of the rotation axis 120a may be substantially horizontal.

  The motor unit 120 and the compression mechanism unit 130 are accommodated in a housing 110 formed by joining the main body housing 111, the end housing 112, and the end housing 113 to each other by welding.

  In this embodiment, the main body housing 111 and the end housings 112 and 113 are all made of iron, the main body housing 111 is formed in a cylindrical shape, and the end housings 112 and 113 are both cap-shaped (shallow bottomed). It is formed in a cylindrical shape. The end housings 112 and 113 are welded so as to close the open ends on both sides of the main body housing 111.

  The end housings 112 and 113 are both formed as bottomed cylindrical members having different depths, but the basic configuration is the same, and the contents thereof will be described below using the end housing 113.

  The end housing 113 is formed in a cylindrical shape and joined to the main body housing 111, an end forming portion 113 b that forms a closing surface that closes the opening of the longitudinal end of the housing 110, and Corresponding to the bent part on the outer peripheral side of the bottom part of the bottomed cylindrical member, there is a connecting part 113c that connects the joint part 113a and the end part forming part 113b.

  In the end housing 113 (112), a portion where the plate thickness is reduced is formed in the region of the connecting portion 113c while the basic plate thickness is t1. That is, a portion having a plate thickness t2 is formed in the connecting portion 113c, and the plate thickness t2 is set to be thinner than the plate thickness t1 of the joint portion 113a and the end portion forming portion 113b. In order to reduce the plate thickness of the connecting portion 113c, it is possible to cope with the connecting portion 113c by cutting or pressing. The plate thickness t1 is equivalent to the plate thickness of the main body housing 111.

  The end housings 112 and 113 formed as described above are inserted such that the outer diameter side surface of the joint portion 113a is inscribed in the inner diameter side surface of the main body housing 111, and the end portion of the main body housing 111 and the joint portion 113a are Welding is performed over the entire circumference with the outer diameter side surface to form the housing 110. The site where welding has been performed is a welded portion 114. A suction port 112a through which refrigerant is sucked is provided on the upper surface side of the end housing 112.

  A space such as the motor chamber 123 formed in the housing 110 communicates with the suction chamber 141 of the compression mechanism unit 130, and a suction refrigerant pressure Ps (a refrigerant pressure before compression) as a predetermined internal pressure is formed on the inner surface of the housing 110. , A pressure substantially equal to the low pressure side pressure) is applied. That is, the electric compressor 100 according to the present embodiment is a so-called low pressure shell type electric compressor in which a pressure lower than the compression / discharge refrigerant pressure is applied to the inner wall surface of the housing 110.

  A support plate 115 to which a bearing (not shown) is fixed and a frame 116 are provided on the end housing 112 side and the middle part in the main body housing 111, respectively, and the drive shaft 131 can be rotated via the bearing (not shown). It is supported by. A communication hole 115 a is formed in the support plate 115 so that the suction side space 112 b formed by the end housing 112 and the support plate 115 communicates with the motor chamber 123. Further, a communication hole 116 a is formed in the frame 116 so that the motor chamber 123 and the suction chamber 141 communicate with each other.

  The motor unit 120 includes a rotor unit 121 and a stator unit 122 that are accommodated in a motor chamber 123 formed in the main body housing 111. The rotor part 121 is fixed to the drive shaft 131, and the stator part 122 is fixed to the inner peripheral surface of the main body housing 111 by press-fitting on the outer peripheral side of the rotor part 121. When electric power from an external power source (not shown) is supplied to the stator portion 122, the drive shaft 131 is rotationally driven with the rotation of the rotor portion 121.

  The compression mechanism unit 130 constitutes a known scroll type compression mechanism having a movable scroll 132 and a fixed scroll 133 as internal members. The fixed scroll 133 is fixed as a fixed member on the opposite side of the frame 116 in the main body housing 111 as a fixed member, and a movable scroll 132 as a movable member is disposed so as to mesh with the fixed scroll 133.

  An eccentric part 131a provided at the tip of the drive shaft 131 is inserted through a bearing (not shown) on the side of the movable scroll 132 opposite to the fixed scroll. And the movable scroll 132 revolves with respect to the fixed scroll 133 with the rotational drive of the drive shaft 131 by the rotation prevention mechanism which is not shown in figure.

  A suction chamber 141 is formed on the outer peripheral side between the scrolls 132 and 133, and a compression chamber 142 is formed toward the center side. In addition, the fixed scroll 133 is formed with a discharge port 133 a for discharging the refrigerant compressed in the compression chamber 142 to the discharge chamber 143. The discharge port 133a is formed as a hole provided in the central portion of the fixed scroll 133, and the discharge chamber 143 is formed on the right side of the fixed scroll 133 in the figure (the end housing 113 side and the counter motor portion side). Yes. Further, the fixed scroll 133 is provided with a discharge port 133b for discharging the refrigerant from the discharge chamber 143 to the outside of the housing 110.

  A space between the end housing 113 and the fixed scroll 133 is formed as an end space 113d and communicates with the motor chamber 123 through a communication path (not shown). Therefore, in the housing 110, the suction side space 112b, the motor chamber 123, and the end side space 113d communicate with each other, and the lubricating oil separated from the refrigerant during the operation of the electric compressor 100 is contained in the housing 110. It collects at the bottom (lower side). The lubricating oil is supplied to the motor unit 120, the sliding part of the compression mechanism part 130, the bearing part, and the like.

  Next, the operation of the electric compressor 100 based on the above configuration will be briefly described.

  When electric power is supplied to the motor unit 120 (stator unit 122) of the electric compressor 100, the movable scroll 132 is revolved by driving the motor unit 120, and the refrigerant flows from the suction port 112a to the suction side space 112b → the communication hole 112a. → Motor chamber 123 → flows into the suction chamber 141 through the communication hole 116a. When the refrigerant is compressed in the compression chamber 142 and reaches a predetermined discharge refrigerant pressure Pd, the refrigerant is discharged from the discharge port 133a to the discharge chamber 143. For example, a suction refrigerant of −30 ° C. to 50 ° C. is compressed in the compression chamber 142 and discharged as a high-temperature refrigerant having a temperature higher than the outside air temperature of 70 ° C. to 150 ° C.

  In such an operation of the electric compressor 100, the suction refrigerant pressure (predetermined internal pressure) Ps is applied to the inner wall surfaces of the suction side space 112b, the motor chamber 123, and the end portion side space 113d of the housing 110 as shown in FIG. Works.

  Then, the main body housing 111 is deformed into a drum shape with the largest amount of deformation at the center in the longitudinal direction. In addition, the end forming portions 113b of the end housings 112 and 113 are deformed so as to bulge outward with a maximum deformation amount at the central portion, and the joint portion 113a is inwardly connected to the inside via the connecting portion 113c. Attempt to transform as if.

  Therefore, as shown in FIG. 3, a portion where welding is not performed in the overlap margin of the main body housing 111 and the joint portion 113 a (between the inner diameter side surface of the main body housing 111 and the end portion of the joint portion 113 a) As shown by the arrows in 3, they spread away from each other, and stress is concentrated on the welded portion 114.

  However, in the present embodiment, since the plate thickness t2 of the connecting portion 113c is thinner than the plate thickness t1 of the joint portion 113a and the end portion forming portion 113b, the end housings 112 and 113 are deformed by the suction refrigerant pressure Ps. When trying to do so, the deformation can be absorbed by the thin portion of the connecting portion 113c and the deformation to the joint portion 113a can be suppressed, so the inner side surface of the main body housing 111 and the end portion of the joint portion 113a It is possible to suppress the deformation that expands the gap, and to suppress the stress concentration on the welded portion 114. Therefore, the pressure resistance strength of the housing 110 can be improved without increasing the physique and weight.

  Moreover, since it is only necessary to form the thin portion of the joint portion 113a, the end portion forming portion 113b, and the connecting portion 113c only in the region of the connecting portion 113c, it is not necessary to thin the entire end housings 112 and 113. Ease of making can be improved.

(Second Embodiment)
In the first embodiment, the plate thickness t2 of the joint portion 113c of the end housings 112 and 113 is set to be thinner than the plate thickness t1 of the joint portion 113a. However, as shown in FIG. In addition, the end forming portion 113b may be thinned. That is, the end portion forming portion 113b and the connecting portion 113c may be continuously formed with the plate thickness t2, and may be formed thinner than the plate thickness t1 of the joint portion 113a. The thinning of the end forming portion 113b and the connecting portion 113c can be handled by cutting or pressing, as in the first embodiment.

  Thereby, the end portion forming portion 113b and the connecting portion 113c are entirely deformed by the refrigerant suction pressure Ps, and the deformation to the joint portion 113a can be absorbed more effectively. Can be improved.

(Other embodiments)
In the first and second embodiments, the case where the thickness of the connecting portion 113c is reduced, or the case where both the end portion forming portion 113b and the connecting portion 113c are reduced in thickness has been described. A thin portion may be formed only in the region.

  Further, the housing 110 is formed by being inserted and welded so that the outer diameter side surface of the joint portion 113a of the end housings 112 and 113 is inscribed in the inner diameter side surface of the main body housing 111, but conversely, the joint portion 113a. The housing 110 may be formed by welding the outer diameter side surface of the main body housing 111 and the end portion of the joint portion 113a such that the inner diameter side surface of the main body housing 111 is covered with the outer diameter side surface of the main body housing 111.

  Further, although the low-pressure shell type electric compressor 100 in which the suction refrigerant pressure Ps acts on the inner wall surface of the housing 110 is not limited to this, the high-pressure shell type electric compressor 100 in which the discharge refrigerant pressure Pd acts on the inner wall surface of the housing 110. You may make it apply to an electric compressor and the electric compressor with which the intermediate pressure of the suction refrigerant pressure Ps and the discharge refrigerant pressure Pd acts.

  Moreover, although the horizontal type electric compressor 100 in which the direction of the rotation axis 120a of the motor unit 120 is substantially horizontal has been described, the direction of the rotation axis is not limited to the horizontal direction. For example, the present invention can be effectively applied to a so-called vertical type electric compressor in which the direction of the rotation axis 120a is substantially vertical.

  Moreover, although the compression mechanism part 130 was a scroll type compression mechanism, it is not limited to this, For example, a vane type compression mechanism part may be sufficient.

  The refrigerant is carbon dioxide and is compressed and pressurized to the supercritical pressure by the compression mechanism unit 130, but is not limited to this. The pressure after compression may be equal to or lower than the critical pressure, or a refrigerant such as chlorofluorocarbon may be used.

  In addition, although the motor unit 120 and the compression mechanism unit 130 are used as devices disposed inside the housing 110 as a pressure vessel, the present invention is not limited to this, and an inflow unit through which a refrigerant flows and a gas-liquid refrigerant are separated. The present invention may be applied to an accumulator, a receiver, or the like in which a gas-liquid separation unit, a gas phase refrigerant, or an outflow part for flowing out a liquid phase refrigerant is used as an internal device.

It is sectional drawing which shows schematic structure of the electric compressor in 1st Embodiment. It is sectional drawing which shows the deformation | transformation state of the housing by the suction | inhalation refrigerant | coolant pressure Ps. FIG. 3 is an enlarged view showing a part III in FIG. 2. It is sectional drawing which shows schematic structure of the electric compressor in 2nd Embodiment.

Explanation of symbols

100 Electric compressor 110 Housing (pressure vessel)
DESCRIPTION OF SYMBOLS 111 Main body housing 112 End part housing 113 End part housing 113a Joint part 113b End part formation part 113c Connection part 130 Compression mechanism part (predetermined apparatus)

Claims (5)

A cylindrical body housing (111);
An end housing (112, 113) for closing an end opening of the main body housing (111),
In a pressure vessel in which a predetermined device (130) is disposed and a predetermined internal pressure (Ps) is applied,
The end housings (112, 113) are
A joining portion (113a) which has a cylindrical shape and is welded to the end portion of the main body housing (111) with an overlap margin;
An end forming portion (113b) that forms a closing surface of the end opening;
A connecting portion (113c) that connects the joint portion (113a) and the end portion forming portion (113b);
A pressure-resistant container, wherein at least a part of the end portion forming portion (113b) and the connecting portion (113c) is formed with a portion whose thickness is thinner than that of the joining portion (113a).   The pressure-resistant container according to claim 1, wherein the portion where the plate thickness is reduced is formed in the connecting portion (113c).   The pressure-resistant container according to claim 1, wherein the portion where the plate thickness is reduced is formed in the entire end portion forming portion (113b) and the connecting portion (113c).   The pressure vessel according to any one of claims 1 to 3, wherein the predetermined device (130) is a compression mechanism (130) that compresses and discharges a working fluid.   The pressure vessel according to claim 4, wherein the working fluid is carbon dioxide.

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