JP2016089710A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a compressor of high efficiency, high reliability, low noise and los cost by achieving volumetric efficiency improvement and noise reduction by surely preventing vane jump, and by achieving slide loss reduction by reducing a slide area and cost reduction by shortening processing time.SOLUTION: An engaging groove 15 has an elliptical cross-sectional shape formed by a circular arc part 15a of 180 degrees or less and a straight line part 15b, and the straight line part 15b forms an angle with respect to a straight line for connecting the center of the circular arc part 15a and the center of a piston 6. Thereby, the piston 6 and a vane 7 are always connected, and vane jump is surely prevented, so that volumetric efficiency improvement and noise reduction can be achieved. At the same time, by reducing a slide area of the engaging groove 15, slide loss is reduced and efficiency of a compressor can be enhanced. In addition, by processing the engaging groove 15 by using a rotationally moving polishing machine, cost can be reduced by shortening processing time.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary compressor used for an air conditioner, a refrigerator, a blower, a water heater, and the like.

  An example of a conventional configuration will be described with reference to a longitudinal sectional view of a rotary high pressure type hermetic compressor of FIG. 14 and a compression mechanism section transverse sectional view of FIG.

  The suction chamber 106 and the compression chamber 107 are formed by sandwiching the cylinder 101, the piston 102, and the vane 103 between the upper bearing 104 and the lower bearing 105, and the compression operation is performed by the piston 102 rotating with the rotation of the drive shaft 108. A compression mechanism 109 and an electric element 110 that transmits a rotational force to the drive shaft 108 are housed in a sealed container 111, and oil used for lubrication and sealing of the compression mechanism 109 is stored in the lower part of the sealed container 111. Has been.

  The vane 103 is fitted and inserted into a vane groove 112 formed in the cylinder 101, and is pressed against the outer peripheral surface of the piston 102 by the discharge pressure acting on the back surface of the vane 103 and the spring force of the vane spring 113, and always the suction chamber 106 and the compression chamber 107. It plays the role of partitioning.

  However, in an operating condition where the compression ratio is very low, a liquid return operation, or the like, a “vane jump” phenomenon in which the vane 103 separates from the piston 102 by pushing the vane 103 back when the compression chamber 107 becomes a discharge pressure or higher pressure. Is generated, and there is a problem in that volume efficiency is reduced and noise is deteriorated due to collision between the vane 103 and the piston 102.

  In order to solve this problem, in the rotary compressor shown in Patent Document 1, as shown in FIG. 16, the vane 103 in which the engaging portion 115 is formed on the distal end side in the engaging groove 114 formed on the outer periphery of the piston 102. Are pivotably connected. With this configuration, vane jumping is reliably prevented.

JP 2000-120572 A

  However, in the conventional configuration of FIG. 15, the vane and the piston are in line contact with each other on the convex surface, whereas in the configuration of Patent Document 1, the convex vane engaging portion and the concave piston engaging groove are surfaces. Since they are in contact with each other, there is a problem that the sliding loss due to the oil viscosity interposed in the gap is relatively large and the input of the compressor is deteriorated.

  In addition, the piston engaging groove has a constricted shape on the outer peripheral side, which is formed by an arc having an angle larger than 180 degrees to prevent vane jumping. Inevitably, there is also a problem that the processing time becomes relatively long, leading to an increase in the cost of the compressor.

The present invention solves the above-mentioned conventional problems, and the engagement groove of the piston has an oval cross-sectional shape formed by an arc portion and a straight portion of 180 degrees or less, and the straight portion is the center of the arc portion. By making an angle with respect to a straight line connecting the piston and the center of the piston, the piston and the vane are always connected in the same manner as in the configuration of Patent Document 1, thereby reliably preventing the vane jumping, and at the same time, the sliding area of the engaging groove Another object of the present invention is to provide a high-efficiency, low-cost, low-noise compressor with a short machining time using a grinding machine that rotates, by reducing the sliding loss.

  In order to solve the conventional problem, the compressor of the present invention includes a cylinder and a piston sandwiched between an upper end plate and a lower end plate, and a vane is fitted into a vane groove provided in the cylinder. A suction chamber and a compression chamber are formed, and the vane is swingably connected to an engagement groove formed in the piston, and the compression mechanism portion that performs a compression operation is sealed by the piston swinging as the drive shaft rotates. A rotary compressor provided inside the container, wherein the engagement groove has an elliptical cross-sectional shape formed by an arc portion and a straight portion of 180 degrees or less, and the straight portion includes an arc portion center and a piston center. An angle is formed with respect to a straight line connecting the two.

  As a result, the piston and the vane are always connected in the same manner as in the configuration of Patent Document 1, so that the vane jump is surely prevented, volume efficiency is improved and noise is reduced, and at the same time, the sliding area of the engaging groove is reduced. This makes it possible to reduce the sliding loss and increase the efficiency of the compressor. In addition, it is possible to reduce the processing time and reduce the cost by processing the engagement groove using a rotating grinder. is there.

  The compressor of the present invention is capable of reducing sliding loss in the engagement groove and improving workability while preventing jumping of the vanes, so that the compressor can be made highly efficient, low in cost, and low in noise. is there.

The longitudinal cross-sectional view of the compressor in Embodiment 1 of this invention AA cross-sectional view of the compression mechanism in the first embodiment of the present invention The expanded cross-sectional view of the compression mechanism part in Embodiment 1 of this invention Explanatory drawing of compression operation of the compression mechanism part in Embodiment 1 of this invention Front view at the time of engaging groove processing in Embodiment 1 of the present invention Side surface sectional view at the time of engaging groove processing in Embodiment 1 of the present invention Enlarged cross-sectional view of the compression mechanism in Embodiment 2 of the present invention Enlarged cross-sectional view immediately after discharge in Embodiment 2 of the present invention Enlarged cross-sectional view of a crank angle of 270 degrees in the second embodiment of the present invention Enlarged cross-sectional view of the compression mechanism in Embodiment 3 of the present invention The expanded cross-sectional view of another compression mechanism part in Embodiment 3 of this invention Enlarged cross-sectional view of the compression mechanism in Embodiment 4 of the present invention Enlarged cross-sectional view of the compression mechanism in Embodiment 5 of the present invention A longitudinal sectional view of a compressor in a conventional compressor Enlarged sectional view of a compression mechanism in a conventional compressor Enlarged sectional view near the suction hole in the compressor of Patent Document 1

  In the first invention, a cylinder and a piston are sandwiched between an upper end plate and a lower end plate, and a vane is inserted into a vane groove provided in the cylinder to form a suction chamber and a compression chamber, and the vane is an engagement formed in the piston. The rotary compressor is provided with a compression mechanism part, which is coupled to the groove so as to be swingable and performs a compression operation by swinging the piston as the drive shaft rotates, and the engagement groove is 180 degrees. It has an oval cross-sectional shape formed by the following arc part and straight part, and the straight part is always connected to the piston and vane by making an angle with the straight line connecting the arc part center and the piston center. Thus, vane jumping can be reliably prevented to improve volumetric efficiency and noise, and at the same time, the sliding area of the engaging groove can be reduced to reduce sliding loss and to increase the efficiency of the compressor.

  In addition, it is possible to reduce the processing time and the cost by processing the engaging groove at high speed using a rotating machine.

  According to a second aspect of the present invention, in the compressor of the first aspect of the invention, an acute angle part and an obtuse angle part are formed at the intersection of the outer periphery of the piston and the engagement groove, and the vane is fitted into the vane groove. A sliding portion that slides, an arcuate engaging portion that is connected to the engaging groove, and a neck portion between the sliding portion and the engaging portion, and the suction chamber side surface and the compression chamber side surface of the vane A relief portion corresponding to the acute angle portion is formed on at least one of the neck portions. If there is no change in the width and length of the vane sliding part, it is unavoidable to increase the diameter of the engaging part and avoid interference between the acute angle part and the vane if an attempt is made without providing a relief part. . However, since this is not necessary in this configuration, the engaging portion can be made relatively small. As a result, the sliding loss can be reduced by reducing the sliding area in the engaging groove.

  In addition, since the vane engagement portion diameter is reduced, the overall length of the vane can be reduced, and the lateral projection area that receives the pressure difference acting on the side surface of the vane, that is, the pressure receiving area is reduced, thereby reducing the lateral load. It is possible to reduce the load on the vane sliding portion that is inserted into the groove and slides. Therefore, it is possible to achieve high efficiency by reducing sliding loss at the sliding portion and high reliability by preventing abnormal sliding.

  By providing the relief portions on both side surfaces of the vane so as to have a line-symmetric shape, it is not necessary to manage the front and back of the vane when assembling the compression mechanism portion, and the cost can be reduced by improving mass productivity.

  In a third aspect of the invention, in particular, in the compressor of the first or second aspect of the present invention, the relief portion is formed on either the suction chamber side surface or the compression chamber side surface, and the neck portion on the other side surface is a straight line extending the sliding portion. As a result, the strength of the neck portion where the relief portion where stress is likely to concentrate is increased, and deformation of the engaging portion due to the load applied from the piston to the engaging portion is suppressed, so that the engagement between the vane engaging portion and the piston is suppressed. The joint groove does not slide locally, and the sliding loss in the engagement groove can be reduced.

  Further, it is possible to achieve high reliability by suppressing vane breakage even in a situation such as a liquid compression operation in which the load applied to the engaging portion is particularly large.

  In the fourth aspect of the invention, in particular, in the compressor of the third aspect of the invention, the escape portion is formed on the side surface of the suction chamber.

  There is always a contact point between the piston engagement groove and the vane engagement part, and with the contact point as a boundary, the suction chamber side surface of the piston engagement groove has a low suction pressure, and the compression chamber side surface is being compressed or compressed. Since a high pressure that has already been applied acts, a moment for the piston to rotate about its central axis is exerted by the pressure difference. Since the moment is received by the vane engaging portion, the contact point between the engaging groove and the engaging portion exists mainly on the suction side under normal operating conditions.

  On the other hand, the arc portion of the piston engaging groove that slides with the vane engaging portion is asymmetric with respect to the axis connecting the center of the arc portion and the center of the piston.

  Therefore, the vane relief portion is formed on the side surface of the suction chamber, that is, by placing the acute angle corner portion of the piston engagement groove in which the arc portion occupies a large amount on the suction chamber side, there is always a contact point on the arc portion of the piston engagement groove. Therefore, abnormal sliding can be avoided.

  Further, since the contact does not move to the linear portion of the piston engaging groove, vane removal from the piston can be prevented, and the compressor can be prevented from being destroyed.

  In the fifth aspect of the invention, in particular, in the compressor of the third aspect of the invention, the relief portion is formed on the side surface of the compression chamber.

  The compression chamber after the piston rotates together with the drive shaft to perform the compression operation and completely discharges the high-pressure gas from the discharge hole is generally called the top clearance volume. It does not contribute to compression by re-expanding into the chamber. Since this top clearance volume causes a decrease in volume efficiency of the compressor and an increase in compression power, it is necessary to make it as small as possible.

  By forming the vane relief portion on the side of the compression chamber, the top clearance volume can be reduced compared to the case where it is formed on the side of the suction chamber, so that the volume efficiency of the compressor is improved and the compression power is reduced. Is possible.

  In a sixth aspect of the invention, in particular, in the compressor of the fifth aspect, when the crank angle of the vane top dead center where the vane is most housed in the vane groove is 0 degree, the crank angle is 270 degrees. Since the surface of the relief part and the surface of the acute angle part that has entered the relief part substantially coincide with each other, the top clearance volume can be minimized, and further improvement of volume efficiency and reduction of compression power can be realized. It is.

  In the seventh aspect of the invention, in particular, in the compressor according to any one of the first to sixth aspects, high finishing accuracy can be achieved by making the thickness of the engaging portion equal to or smaller than the thickness of the sliding portion of the vane. It is possible to easily process the two surfaces of the vane sliding portion that requires the reduction of the sliding loss by improving the lubrication state at the vane sliding portion and the cost by shortening the processing time.

  In an eighth aspect of the invention, in particular, in the compressor according to any one of the first to seventh aspects, high rigidity which is an advantage of the wheel type polishing machine is obtained by polishing the engagement groove of the piston with a wheel type grinding stone. High-precision machining can be performed at high speed, the engagement groove arcuate part is finished with higher accuracy, the sliding loss is reduced by improving the lubrication state, and the clearance between the piston engagement groove and the vane engagement part Volume efficiency can be improved by suppressing gas leakage from the compression chamber passing through the suction chamber to the suction chamber.

  In addition, since the circular arc portion and the linear portion of the engagement groove can be simultaneously finished at a high speed, the machining time can be shortened and the cost can be reduced.

  Moreover, since the wheel-type grindstone is a tool that is generally widely used, it can be obtained at a low cost and the cost can be further reduced.

  According to a ninth aspect of the invention, in particular, in the compressor of any one of the first to eighth aspects, at least one of the piston and the vane is made of a material formed by near net shape molding, so that a relatively complicated shape is obtained. The parts it has can be used without processing or with fewer processing steps, and the cost can be reduced by shortening the processing time.

  As a method of near net shape molding, mold molding methods such as sintering and forging are common and inexpensive, but sheet-shaped material powder having a predetermined cross-sectional shape is baked and solidified with a laser to form a laminate. If molding is performed by additive manufacturing methods represented by various methods, etc., it can be manufactured as an assembly part with the piston and vane connected, and complex shapes that cannot be processed by the mold molding method can be realized, so design freedom It becomes possible to provide a compressor with increased volume, smaller sliding loss, and higher volumetric efficiency.

According to a tenth aspect of the invention, in particular, in the compressor according to any one of the first to ninth aspects, an atmosphere around the compression mechanism portion is lower than a discharge pressure.

  Compared with high-pressure compressors, high-pressure and high-pressure gas discharged from the compression mechanism is discharged to the outside of the compressor without radiating and depressurizing the low-pressure compressor, which is mostly the suction pressure in the sealed container. Therefore, for example, in an air conditioner, the performance of the air conditioner can be improved by improving the heating capacity and increasing the speed at which the blowing temperature during heating increases.

  Another advantage of the low-pressure compressor is that the closed container takes on the function of an accumulator that separates the suction refrigerant that has been in the gas-liquid two-phase state and avoids liquid compression. In addition, there is no need to provide a separate accumulator in the suction pipe, and cost reduction can be expected by reducing the number of parts.

  However, since it is not easy to apply a high pressure to the back of the vane in the low pressure type rotary compressor, there is a problem that vane jumping easily occurs due to insufficient pressing force on the piston, and the vane does not jump. It is optimal to adopt the configuration of the present invention that can realize high reliability and low cost.

  Note that the inside of the sealing device does not necessarily have to be the suction pressure. For example, in a two-stage compressor used in the injection cycle, the periphery of the compression mechanism is an intermediate pressure atmosphere between the suction pressure and the discharge pressure. Even in the case of an intermediate pressure type compressor, there is still a problem that the vane jumps more easily than in the high pressure type compressor. Therefore, the effect of the present invention can be exhibited as in the case of the low pressure type compressor.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
1 is a longitudinal sectional view of a compressor according to Embodiment 1 of the present invention, and FIG. 2 is a transverse sectional view taken along a line AA in FIG.

  The electric element 2 is accommodated in the sealed container 1. The compression mechanism unit 4 is driven by the vertical drive shaft 3 of the electric element 2. The compression mechanism unit 4 is configured to perform a compression operation by forming a suction chamber 10 and a compression chamber 11 by sandwiching a cylinder 5 and a piston 6 and a vane 7 between an upper bearing 8 and a lower bearing 9. The cylinder 5 houses a crankshaft eccentric portion 12 integrally formed with the drive shaft 3, and a piston 6 is rotatably mounted on the crankshaft eccentric portion 12. The vane 7 is fitted and inserted into a vane groove 13 provided in the cylinder 5 and can linearly move in the longitudinal direction of the vane 7. At the same time, an engagement portion 14 mainly composed of an arc is formed on the tip side of the vane 7. The suction chamber 10 is swingably connected to an engagement groove 15 formed in the piston 6 to partition the suction chamber 10 and the compression chamber 11. The cylinder 5 is provided with a suction hole 16 adjacent to the suction chamber 10. A suction liner 17 is press-fitted into the suction hole 16 to partition the high-temperature and high-pressure discharge gas inside the sealed container 1 and the low-temperature and low-pressure suction gas inside the suction hole 16. An accumulator 18 is inserted into the suction liner 17 to prevent liquid compression of the compressor, and is connected by brazing or welding together with a suction outer tube 19 fixed to the hermetic container 1 so as to be sucked into the compressor. The working fluid is separated into gas and liquid.

  When the electric element 2 is energized and its drive shaft 3 rotates, the crankshaft eccentric portion 12 rotates eccentrically in the cylinder 5, and the vane 7 that moves linearly in the vane groove 13 and the piston 6 are always connected. In this state, the piston 6 swings and the working fluid is repeatedly sucked and compressed.

FIG. 3 is an enlarged cross-sectional view of the compression mechanism unit 4. For simplicity, parts and holes that are not necessary for explanation are omitted.

  The engagement groove 15 of the piston 6 has an oval cross-sectional shape formed by an arc portion 15a and a straight portion 15b of 180 degrees or less, and a straight line connecting the center of the arc portion 15a and the center of the piston 6. The straight portion 15b has an angle, and an acute angle portion 15c and an obtuse angle portion 15d are formed at the intersection between the engagement groove 15 and the outer periphery of the piston 6. The acute angle portion 15c is chamfered.

  The vane 7 includes an engaging portion 14 having substantially the same diameter as the arc portion 15a of the engaging groove 15, a sliding portion 7a that is inserted into and slides in the vane groove 13, and the engaging portion 14 and the sliding portion 7a. A relief portion 7c is formed on the suction chamber 10 side of the neck portion 7b so that the acute angle portion 15c of the piston 6 does not interfere with the neck portion 7b.

  About the compressor comprised as mentioned above, the operation | movement and an effect | action are demonstrated below.

  First, the compression operation of the compression mechanism unit 4 will be described with reference to FIG.

  The piston 6 swings while the engagement groove 15 is connected to and restrained by the vane 7. When the vane 7 is stored most in the vane groove 13, that is, when the crank angle at the top dead center position is 0 degree, the intake gas is sucked into the suction hole for one rotation, that is, the crank angle is 0 degree to 360 degrees. After the suction from 16 to the suction chamber 10, the next rotation becomes the compression chamber 11, and the gas is compressed by reducing the volume of the compression chamber 11. The gas that has reached a predetermined discharge pressure with a crank angle of 180 degrees or more, depending on the operating conditions, is provided in the upper bearing 8 and is not shown in the drawing and is located on the opposite side of the vane 7 from the suction hole 16. It is discharged from the hole 20 into the closed container 1 internal space.

  The tip side of the vane 7 is in contact with the low-pressure suction chamber 10 and the compression chamber 11 which is lower than the discharge pressure under normal operating conditions for approximately half a revolution or more, whereas the back side of the vane 7 is always at the discharge pressure atmosphere. Therefore, the vane 7 is operated by being pressed against the piston 6. However, in an operation condition with a low compression ratio in which the pressure in the compression chamber 11 immediately reaches the discharge pressure, or in a liquid compression operation in which the pressure rises to a pressure higher than the discharge pressure due to pressure loss in the discharge hole, the vane 7 is removed from the piston 6. A force in the direction opposite to that during normal operation is attempted.

  In the configuration of the present invention, since the vane 7 and the piston 6 are connected, there is no so-called “vane jump”, and the vane 7 moves away from the piston 6 so that the gas in the compression chamber 11 leaks to the suction chamber 10 and the volumetric efficiency decreases. Or abnormal noise generated by repeated collision between the vane 7 and the piston 6 does not occur, and high volumetric efficiency and low noise can be realized.

  Further, in the conventional configuration in which the vane 7 is pressed against the piston 6 due to the pressure difference, it is necessary to provide a space for storing the vane spring 113 as shown in FIG. 15, and the total length of the vane groove 112 is limited. On the other hand, in the configuration of the present invention, since the vane spring 113 is unnecessary and there is no need to provide a storage space, a sufficient overall length of the vane groove 13 can be secured to reduce sliding loss and improve reliability by dispersing the surface pressure. It is possible to reduce the cost by reducing the processing steps.

  In order to prevent the vane 7 from always coming off the piston 6, the arc portion 15 a of the engagement groove 15 of the piston 6 hooks the arc-shaped engagement portion 14 of the vane 7 at all crank angles, and is applied upward to the vane 7. It is necessary to support the power of.

  In the configuration of Patent Document 1, the above-mentioned correspondence is performed by setting the arc portion 15a of the engagement groove 15 of the piston 6 to be larger than 180 degrees, and both the piston 6 and the vane 7 are symmetrical, so that the hook width is always approximately. It is constant.

  On the other hand, in the configuration of the present invention, in FIG. 4, the hook width is the smallest at the moment of the crank angle of 270 degrees, that is, the crank angle that is geometrically the easiest for the vane 7 to come off from the piston 6, It is a point to make sure that the vane does not jump.

  In the configuration of Patent Document 1, since the arc portion 15a of the engagement groove 15 is larger than 180 degrees, both ends of the engagement groove 15 must be acute angles. If the width and length of the sliding portion 7a are not changed, it is necessary to increase the diameter of the engaging portion 14 or to form deep relief portions 7c on both sides of the vane 7 in order to avoid interference.

  On the other hand, in the configuration of the present invention, since the arc portion 15a of the engagement groove 15 is 180 degrees or less, the diameter and angle of the arc portion 15a can be designed to be small, and the sliding portion between the engagement groove 15 and the engagement portion 14 can be designed. By making the sliding area relatively small, sliding loss can be reduced and the compressor can be made highly efficient.

  Further, the overall length of the vane 7 can be reduced by reducing the diameter of the engaging portion 14, and the lateral projection area that receives the pressure difference acting on the side surface of the vane 7, that is, the pressure receiving area can be reduced, thereby reducing the lateral load. Therefore, it is possible to reduce the load on the sliding portion 7a that is inserted into the vane groove 13 and slides. Therefore, it is possible to achieve high efficiency by reducing sliding loss at the sliding portion 7a and high reliability by preventing abnormal sliding. Hereinafter, each embodiment will be described assuming that the width and length of the sliding portion 7a are not changed, but there is no change in the relative relationship between the sliding portion 7a and the engaging portion 14, and the sliding portion 7a is not changed. A configuration in which the dimensions of the moving part 7a and other related parts and parts are changed is also included in the present invention.

  The escape portion 7c of the vane 7 is formed only on the suction chamber 10 side, and the compression chamber 11 side of the neck portion 7b is a straight line extending the sliding portion 7a. Therefore, compared with the configuration of Patent Document 1 in which deep relief portions 7c are formed on both sides, the strength of the neck portion 7b in which the relief portion 7c in which stress is easily concentrated is increased, and due to the load applied from the piston 6 to the engagement portion 14 Since deformation of the engagement portion 14 is suppressed, the engagement portion 14 of the vane 7 and the engagement groove 15 of the piston 6 do not slide locally, and the sliding loss in the engagement groove 15 is reduced. Can do. At the same time, even in a situation such as a liquid compression operation where the load applied to the engaging portion 14 is particularly large, the vane 7 can be prevented from being broken and high reliability can be realized.

  Since the engaging portion 14 of the arcuate vane 7 is required to be fitted in the engaging groove 15 of the arcuate piston 6 and slide smoothly, the engaging portion 14 is larger than the diameter of the engaging groove 15. The engagement groove 15 and the engagement portion 14 are always in line contact with each other, not in surface contact, due to the slight difference in diameter. In the cross-sectional view of FIG. 3, the line contact portion is referred to as a contact.

  A low suction pressure acts on the surface on the suction chamber 10 side of the engagement groove 15 and the compression chamber 11 side acts on the surface on the compression chamber 11 side. Has a moment to rotate clockwise about its central axis. Since the moment is received by the engaging portion 14 of the vane 7, the contact point between the engaging groove 15 and the engaging portion 14 exists mainly on the suction chamber 10 side under normal operating conditions.

  On the other hand, the arc portion 15a of the engagement groove 15 that slides with the engagement portion 14 is asymmetric with respect to the axis connecting the center of the arc portion 15a and the center of the piston 6 and is offset toward the suction chamber 10 side.

  Therefore, by adopting the configuration of the present embodiment, there is always a contact in the arc portion 15a of the engagement groove 15, so that abnormal sliding can be avoided, and the straight line of the engagement groove 15 can be avoided. Since the contact does not move to the portion 15b, the phenomenon that the vane 7 is removed from the piston 6 can be prevented, and the compressor can be prevented from being destroyed.

  The vane 7 is generally made of a material harder than the cylinder 5, and when the relief portion 7c of the vane 7 with a crank angle of 0 degrees enters the vane groove 13, the edge of the relief portion 7c becomes the vane. In order to prevent abnormal wear of the vane groove 13 due to rubbing with the groove 13, it is preferable to provide a chamfer 21 at the end of the vane groove 13 to avoid edge contact of the escape portion 7c. At this time, if chamfering of the same dimension is also provided at the end portion of the vane groove 13 on the opposite side, the workability is improved.

  FIG. 5 and FIG. 6 are a front view and a cross-sectional view seen from the side for explaining an example of the processing method of the engaging groove 15 of the piston 6. The disk-shaped wheel-type grindstone 23 that rotates about the rotation shaft 22 is shown in FIG. After moving in the direction of the arrow in FIG. 5, the engaging groove 15 is formed by polishing in the direction of the arrow in FIG.

  In this processing method, the arc portion 15a of the engagement groove 15 is always formed at 180 degrees or less. In other words, this processing method can be used only when the arc portion 15a of the engagement groove 15 is 180 degrees or less.

  The wheel-type polishing machine has advantages such as high tool rigidity, high processing accuracy, and high processing speed. Taking advantage of these features, the arc portion 15a of the engagement groove 15 is finished with higher accuracy and lubricated. At the same time as reducing the sliding loss by improving the state, it is possible to suppress the gas leakage from the compression chamber 11 passing through the gap between the engagement groove 15 and the engagement portion 14 to the suction chamber 10 and also improve the volume efficiency. In addition, since the circular arc portion 15a and the linear portion 15b of the engagement groove 15 can be finished at the same time and at a high speed, the machining time can be shortened and the cost can be reduced.

  Moreover, since the wheel type grindstone 23 is a tool that is generally widely used, it can be obtained at a low cost, and the cost can be further reduced.

  In addition, it is possible to process by the method of processing the engagement groove 15 having the configuration of Patent Document 1, such as polishing with a broaching machine or a linearly moving grindstone, wire cutting, or cutting by rotating one or more blades. However, it is considered inferior to a wheel type grinder in terms of accuracy.

  Further, at least one of the piston 6 and the vane 7 is made of a material formed by near net shape molding, and is completed by a single finishing process using a wheel type polishing machine, so that the engagement groove of the piston 6 having a complicated shape is obtained. 15 and the engagement part 14 of the vane 7 and the relief part 7c can be manufactured with few processing steps, and the cost can be reduced by shortening the processing time.

  As a method of near net shape molding, mold molding methods such as sintering and forging are common and inexpensive, but sheet-shaped material powder having a predetermined cross-sectional shape is baked and solidified with a laser to form a laminate. If it is molded by the additive manufacturing method represented by the method of going, etc., it can be produced as an assembly part with the piston 6 and the vane 7 connected, and a complicated shape that cannot be processed by the mold molding method can be realized. It becomes possible to provide a compressor with higher design freedom, lower sliding loss, and higher volumetric efficiency.

  In addition, it is not always necessary to perform a finishing process with a wheel-type polishing machine, and as long as the accuracy after near-net shape molding can be satisfied, it may be used as a part without processing.

  Since the diameter of the engaging portion 14 of the vane 7 is equal to or smaller than the thickness of the sliding portion 7a, the sliding portion 7a that requires high finishing accuracy can be reasonably ground. It is possible to reduce the sliding loss by improving the lubrication state, and it is also possible to reduce the cost by shortening the processing time by simplifying the processing.

  Although this embodiment has been described as a high-pressure compressor in which the inside of the sealed container 1 is filled with the discharge gas, a case of a low-pressure compressor in which most of the inside of the sealed container 1 is the suction pressure will be described.

  Compared with a high-pressure compressor, a low-pressure compressor discharges high-temperature and high-pressure gas discharged from the compression mechanism unit 4 to the outside of the compressor without radiating and depressurizing. The air conditioner performance can be improved by increasing the rising speed of the blowing temperature during heating.

  Further, as another advantage of the low-pressure compressor, since the hermetic container 1 has a function of the accumulator 18 for separating the refrigerant sucked into the gas-liquid two-phase state into gas-liquid separation and avoiding liquid compression, the high-pressure compressor Thus, it is not necessary to separately provide the accumulator 18 in the suction pipe, and cost reduction by reducing the number of parts can be expected.

  However, since it is not easy to apply a high pressure to the back surface of the vane 7 in the low-pressure rotary compressor, there is a problem that vane jumping due to insufficient pressing force on the piston 6 occurs, and the vane does not jump. It is optimal to adopt the configuration of the present invention that can realize high efficiency, high reliability, and low cost.

  The inside of the sealed container 1 is not necessarily at the suction pressure. For example, in a two-stage compressor used in the injection cycle, the periphery of the compression mechanism 4 is an intermediate pressure atmosphere between the suction pressure and the discharge pressure. Even in such an intermediate pressure type compressor, there still remains a problem that vane jumps more easily than in a high pressure type compressor, so that the effect of the present invention can be exhibited as in the case of a low pressure type compressor.

(Embodiment 2)
FIG. 7 is an enlarged cross-sectional view of the compression mechanism unit 4 according to Embodiment 2 of the present invention.

  The relief portion 7c of the vane 7 is formed only on the compression chamber 11 side, the suction chamber 10 side of the neck portion 7b is a straight line extending the sliding portion 7a, and the diameter of the engaging portion 14 is set to the thickness of the sliding portion 7a. Since they are equivalent, the sliding loss can be reduced and the cost can be reduced by the high rigidity of the vane 7 and the simplification of processing, as in the first embodiment.

  FIG. 8 is an enlarged cross-sectional view at a crank angle immediately after the high-pressure gas in the compression chamber 11 has been completely discharged from the discharge hole 20.

  In FIG. 8, the compression chamber 11 in which the gap still remains is generally called a top clearance volume 24, and the high-pressure gas remaining therein re-expands into the low-pressure suction chamber 10 and does not contribute to compression. Since this top clearance volume causes a decrease in volume efficiency of the compressor and an increase in compression power, it is necessary to make it as small as possible.

  As a method for reducing the top clearance volume, a relief portion 7c is formed on the compression chamber 11 side, and an acute angle portion at a crank angle of 270 degrees where the acute angle portion 15c of the piston 6 bites most into the vane 7 is shown in FIG. 15c and the escape portion 7c are substantially matched.

  With this configuration, it is possible to minimize the top clearance volume, improve the volume efficiency of the compressor, and reduce the compression power.

As described in the first embodiment, the piston 6 tries to rotate clockwise due to the pressure difference at the contact point in the engagement groove 15, so that the contact point moves to the straight portion 15 b of the engagement groove 15. Although possibility becomes high, it can avoid sufficiently by always keeping a contact in the circular arc part 15a with a suitable dimension structure and driving | running condition.

(Embodiment 3)
FIG. 10 is an enlarged cross-sectional view of the compression mechanism unit 4 according to Embodiment 3 of the present invention. The escape portion 7c of the vane 7 is formed on both sides of the suction chamber 10 and the compression chamber 11 and is symmetrical.

  In this configuration, the rigidity of the vane 7 is inferior to that of the configuration in which the relief portion 7c is formed on one side. However, since the front and back management of the vane 7 is not required when the compression mechanism portion 4 is assembled, mass production is achieved by omitting the assembly process. There is an advantage that the performance is improved and the cost of the compressor can be reduced.

  In FIG. 10, by making the diameter of the engaging portion 14 equal to the thickness of the sliding portion 7a, the sliding portion 7a can be easily surface ground, and as in the first embodiment, the sliding portion 7a slides. Although a reduction in dynamic loss and a reduction in cost can be realized, the same effect can be obtained even if the diameter of the engaging portion 14 is smaller than the thickness of the sliding portion 7a as shown in FIG. In addition, in the configuration of FIG. 11, the overall length of the vane 7 can be reduced as compared with the configuration of FIG. 10, and the lateral load due to the pressure difference acting on the side surface of the vane 7 can be reduced. It is possible to reduce the load on the moving sliding portion 7a. Therefore, it is possible to achieve high efficiency by reducing sliding loss at the sliding portion 7a and high reliability by preventing abnormal sliding.

(Embodiment 4)
FIG. 12 is an enlarged cross-sectional view of the compression mechanism unit 4 according to Embodiment 4 of the present invention. The escape portion 7c of the vane 7 is formed on the compression chamber 11 side, and the diameter of the engagement portion 14 is slid. By making it larger than the thickness of the moving part 7a, the rigidity of the vane 7 can be further improved, and deformation of the vane 7 can be suppressed even under operating conditions of high differential pressure and high compression ratio, particularly using carbon dioxide as a refrigerant. It is possible to achieve dynamic loss reduction, high reliability, and low cost.

(Embodiment 5)
FIG. 13 is an enlarged cross-sectional view of the compression mechanism portion 4 according to Embodiment 5 of the present invention, in which the diameter of the engaging portion 14 is made larger than the thickness of the sliding portion 7a, and at the same time, the escape portion 7c is not provided. .

  In this configuration, the effect of the same rigidity improvement as in the fourth embodiment can be obtained, and it is not necessary to provide a large chamfer 21 at the end of the vane groove 13 for avoiding the edge contact of the escape portion 7c. It is possible to secure a sufficient length of 13 and reduce sliding loss and improve reliability by dispersing the surface pressure.

  As described above, the compressor according to the present invention has an elliptical cross-sectional shape in which the engagement groove is formed by the arc portion and the straight portion having an angle of 180 degrees or less, and the straight portion has the arc portion center and the piston center. By making an angle with respect to the straight line connecting the piston and the vane, the piston and vane are always connected to reliably prevent the jumping of the vane, thereby improving the volume efficiency and reducing the noise, and at the same time reducing the sliding area of the engaging groove This makes it possible to reduce the sliding loss and increase the efficiency of the compressor. In addition, it is possible to reduce the processing time and reduce the cost by processing the engagement groove using a rotating grinder. Yes, in addition to air conditioners and heat pump water heaters that use HFC refrigerants, HCFC refrigerants, and HFO refrigerants, they can also be applied to applications such as air conditioners and heat pump water heaters that use natural refrigerant carbon dioxide. That.

DESCRIPTION OF SYMBOLS 1 Airtight container 3 Drive shaft 4 Compression mechanism part 5 Cylinder 6 Piston 7 Vane 7a Sliding part 7b Neck part 7c Escape part 8 Upper bearing 9 Lower bearing 10 Suction chamber 11 Compression chamber 13 Vane groove 14 Engagement part 15 Engagement groove 15a Arc Part 15b Straight part 15c Acute angle part 15d Obtuse angle part 23 Wheel type grindstone

Claims (10)

A cylinder and a piston are sandwiched between an upper end plate and a lower end plate, and a vane is inserted into a vane groove provided in the cylinder to form a suction chamber and a compression chamber. The vane is swung into an engagement groove formed in the piston. A rotary compressor that is movably connected and includes a compression mechanism portion that performs a compression operation by swinging the piston with the rotation of the drive shaft,
The engagement groove has an oval cross-sectional shape formed by an arc portion and a straight portion of 180 degrees or less, and the straight portion has an angle with respect to a straight line connecting the arc portion center and the piston center. A rotary compressor characterized by being provided.   An acute angle corner and an obtuse angle corner are formed at the intersection of the outer periphery of the piston and the engagement groove, and the vane is inserted into the vane groove and slides, and the engagement groove An arc-shaped engaging portion connected to the sliding portion, and a neck portion between the sliding portion and the engaging portion, and at least one of the suction chamber side surface and the compression chamber side surface of the vane The rotary compressor according to claim 1, wherein a relief portion corresponding to the acute angle corner portion is formed at a neck portion.   3. The rotary compressor according to claim 1, wherein the relief portion is formed on one of the suction chamber side surface and the compression chamber side surface, and the neck portion on the other side surface is a straight line extending the sliding portion.   The rotary compressor according to claim 3, wherein the escape portion is formed on a side surface of the suction chamber.   The rotary compressor according to claim 3, wherein the relief portion is formed on a side surface of the compression chamber.   When the crank angle at the top dead center of the vane most stored in the vane groove is 0 degree, the angle of the relief part and the acute angle that has entered the relief part when the crank angle is 270 degrees. The rotary compressor according to claim 5, wherein the surfaces of the corners substantially coincide with each other.   The rotary compressor according to any one of claims 1 to 6, wherein a thickness of the engaging portion is equal to or smaller than a thickness of the sliding portion of the vane.   The rotary compressor according to any one of claims 1 to 7, wherein the engagement groove of the piston is polished by a wheel-type grindstone.   The rotary compressor according to any one of claims 1 to 8, wherein at least one of the piston and the vane is made of a material formed by near net shape molding. The rotary compressor according to any one of claims 1 to 9, wherein the periphery of the compression mechanism section is an atmosphere lower than a discharge pressure.