JP6187267B2 - Electric compressor - Google Patents

Description

  The present invention relates to an electric compressor, and more particularly to an electric compressor with an injection mechanism.

As a conventional technique of an electric compressor, for example, a scroll compressor disclosed in Patent Document 1 is known.
The scroll compressor disclosed in Patent Document 1 includes a power save mechanism that performs capacity control by bypassing refrigerant gas being compressed to the low pressure side. The power saving mechanism includes a cover provided on the upper surface of the end plate of the fixed scroll, and a back pressure passage through which high-pressure refrigerant gas or low-pressure refrigerant gas is selectively supplied from the unit circuit via the high-pressure guide pipe, A bypass passage communicating with the back pressure passage is formed. The bypass passage includes a first save hole and a second save hole that are formed through the fixed scroll end plate and communicate with the compression chamber, and a return hole that communicates with the low pressure chamber. The first save hole, the second save hole, A first save valve, a second save valve, and a valve body are provided in each opening on the bypass passage side of the return hole. The first save valve, the second save valve, and the valve body can be opened and closed by the pressure of the refrigerant gas supplied to the bypass passage.

  Opening / closing control of the first save valve, the second save valve and the valve body is performed in accordance with the pressure of the refrigerant gas supplied from the high pressure guide pipe to the bypass passage through the back pressure passage. When high-pressure refrigerant gas is supplied from the high-pressure guide pipe to the bypass passage through the back pressure passage, the first save valve, the second save valve, and the valve body move in the valve closing direction, and the first save hole, The second save hole and the return hole are shielded. When the low pressure refrigerant gas is supplied from the high pressure guide pipe to the bypass passage through the back pressure passage, the first save valve, the second save valve, and the valve body move in the opening direction, and the first save hole, The second save hole and the return hole are opened.

JP-A-8-303361

  However, in the scroll compressor disclosed in Patent Document 1, in order to stabilize the pressure of the refrigerant gas supplied from the high pressure guide pipe to the bypass passage via the back pressure passage, it is necessary to expand the bypass passage. In order to expand the bypass passage, it is necessary to increase the thickness of the cover, but there is no space between the end cap and the bypass passage that can be sufficiently expanded. Even if the bypass passage can be expanded to some extent, the discharge chamber formed between the end cap and the cover is conversely reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to easily increase the volume of the injection chamber and to efficiently reduce the pressure pulsation of the intermediate-pressure refrigerant introduced into the injection chamber. It is in the provision of an electric compressor that can do this.

In order to solve the above problems, the invention according to claim 1 is formed in an electric motor and a motor housing having a compression mechanism for compressing a refrigerant sucked by rotation of the electric motor, and the compression mechanism. A discharge housing having a discharge chamber for discharging the refrigerant compressed in the compression chamber, and the compression mechanism has an intermediate pressure higher than the suction pressure of the sucked refrigerant and lower than the discharge pressure of the discharged refrigerant. An electric compressor provided with an injection port for introducing a refrigerant from an external refrigerant circuit into the compression chamber in the middle of compression, having an introduction port for introducing the intermediate-pressure refrigerant from the external refrigerant circuit, the introduction A communication passage that connects the port and the injection port is provided, and an intermediate pressure housing having a muffler chamber whose volume is larger than that of the communication passage is provided in the middle of the communication passage. The intermediate pressure housing, the disposed between the motor housing and the discharge housing, the motor housing, the discharge housing and the intermediate pressure housing is laminated, the motor housing, in the discharge housing and said intermediate pressure housing Are each formed with a bolt fastening hole, and the motor housing, the discharge housing and the intermediate pressure housing are integrally fixed by a bolt inserted into the bolt fastening hole, and the muffler chamber is disposed to face the discharge chamber, A partition member that partitions the muffler chamber and the discharge chamber is provided.

According to the first aspect of the present invention, the intermediate pressure housing is provided with a communication path that connects the introduction port and the injection port, and is provided with a muffler chamber whose volume is larger than that of the communication path. Therefore, it is possible to reduce the pressure pulsation of the intermediate pressure refrigerant introduced into the muffler chamber via the introduction port. Further, since the muffler chamber is disposed opposite to the discharge chamber and is provided with a partition member that partitions the muffler chamber and the discharge chamber, the volume of the muffler chamber can be easily increased. Therefore, it is possible to easily increase the volume of the muffler chamber and efficiently reduce the pressure pulsation of the refrigerant introduced into the muffler chamber. Also, an intermediate pressure housing having an introduction port that introduces an intermediate pressure refrigerant and a communication passage that communicates the introduction port and the injection port is prepared, and a motor housing, a discharge housing, and an intermediate pressure housing are laminated, and each bolt A bolt may be inserted into the fastening hole and fixed together. Therefore, it is possible to easily add an injection mechanism. The injection mechanism refers to a mechanism that introduces an intermediate pressure refrigerant that is higher than the suction pressure and lower than the discharge pressure into the compression chamber.

  According to a second aspect of the present invention, in the electric compressor according to the first aspect, the partition member includes a bottom plate and a side wall extending from the bottom plate toward the intermediate pressure housing, and the side wall is surrounded by the discharge chamber. It is characterized by.

  According to the second aspect of the present invention, since the partition member includes the bottom plate and the side wall, and the side wall is surrounded by the discharge chamber, the volume of the muffler chamber can be easily increased.

According to a third aspect of the present invention, in the electric compressor according to the first or second aspect , a concave portion is provided on the discharge housing side of the intermediate pressure housing so as to expand the volume of the discharge chamber to the outer peripheral side of the muffler chamber. Is formed.

According to the third aspect of the present invention, the intermediate pressure housing is formed with the recess that enlarges the volume of the discharge chamber, so that the volume of the discharge chamber is reduced by the side wall of the partition member being surrounded by the discharge chamber. Can be supplemented.

According to a fourth aspect of the present invention, in the electric compressor according to any one of the first to third aspects, the discharge housing includes a protrusion that protrudes toward the partition member, and the protrusion A diaphragm is formed between the partition member and the partition member.

According to the fourth aspect of the present invention, since the throttle is formed between the protruding portion and the partition member, it is possible to reduce the pressure pulsation of the refrigerant discharged from the discharge chamber.

According to a fifth aspect of the present invention, in the electric compressor according to the fourth aspect , the projecting portion is formed with a communication passage that communicates the discharge port and the discharge chamber, and the partition member includes the communication passage. A concave portion is formed so as to cover the protruding side opening, and the diaphragm is formed between the protruding side opening and the concave portion.

According to the fifth aspect of the present invention, since the throttle is formed between the protruding side opening and the concave portion, it is possible to reduce the cross-sectional area of the discharge passage extending from the discharge chamber to the communication passage.

  According to the present invention, the number of muffler chambers (injection chambers) can be easily increased, and the pressure pulsation of the intermediate-pressure refrigerant introduced into the muffler chamber can be efficiently reduced.

It is a longitudinal section showing an electric compressor concerning an embodiment of the present invention. It is an AA arrow directional view in FIG. It is a longitudinal cross-sectional view which expands and shows the valve block in FIG. It is a BB line arrow directional view in FIG. It is a CC arrow view in FIG. It is a perspective view which shows the external appearance of a partition member. It is a longitudinal cross-sectional view which shows the mounting state of a partition member. It is a longitudinal cross-sectional view which shows the mounting state of a partition member.

Hereinafter, an electric compressor according to an embodiment of the present invention will be described with reference to FIGS.
An electric compressor according to an embodiment of the present invention is a vehicle-mounted scroll-type electric compressor (abbreviated as an electric compressor) mounted on an electric vehicle.
The electric compressor constitutes a part of the refrigerant circuit in the vehicle air conditioner.

As shown in FIG. 1, in the electric compressor 10, a compression mechanism 11 that compresses a refrigerant as a fluid and an electric motor 12 that drives the compression mechanism 11 are integrated.
A housing 13 constituting the housing of the electric compressor 10 is a metal housing, and is formed of an aluminum-based metal material in the present embodiment.
The housing 13 has a motor housing 14, a valve block 15, and a discharge housing 16, and the valve block 15 constitutes a part of the outer shell of the housing 13. The valve block 15 corresponds to an intermediate pressure housing.
The motor housing 14, the valve block 15 and the discharge housing 16 are laminated, and the motor housing 14, the valve block 15 and the discharge housing 16 are integrally fixed by bolts 17.

  A screw hole 53 is formed in the end of the motor housing 14 on the valve block 15 side in parallel with the axial direction. A plurality of screw holes 53 are formed at equal intervals in the circumferential direction. Bolts 17 are screwed into the screw holes 53, and the motor housing 14, the valve block 15, and the discharge housing 16 are integrally fixed. The screw hole 53 corresponds to a bolt fastening hole.

A compression mechanism 11 and an electric motor 12 are accommodated in the motor housing 14 of the electric compressor 10.
The compression mechanism 11 includes a fixed scroll 18 and a movable scroll 19, and a compression chamber 20 is formed in the compression mechanism 11 by the fixed scroll 18 and the movable scroll 19.
A suction port 21 is formed in the motor housing 14. The suction port 21 is connected to an external refrigerant circuit (not shown), and when the electric compressor 10 is compressed, low-pressure refrigerant is sent from the external refrigerant circuit to the inside of the motor housing 14 via the suction port 21. Is done.

A shaft support member 22 is provided between the fixed scroll 18 and the electric motor 12 in the motor housing 14.
The shaft support member 22 includes a bearing 24 that constitutes a part of the compression mechanism 11 and supports one end of the rotary shaft 23 provided in the electric motor 12.
The other end of the rotary shaft 23 is supported by the motor housing 14 via a bearing 25.
A suction port 26 communicating with the compression chamber 20 is formed in the shaft support member 22, and the refrigerant sucked into the motor housing 14 from the suction port 21 is introduced into the compression chamber 20 through the suction port 26.
A fixed side pin 27 is press-fitted into the shaft support member 22, and the fixed side pin 27 protrudes toward the movable scroll 19.

An eccentric shaft 28 that protrudes toward the fixed scroll 18 is provided at the end of the rotary shaft 23 on the fixed scroll 18 side.
The axis Q of the eccentric shaft 28 is set at a position eccentric with respect to the axis P of the rotating shaft 23. When the rotating shaft 23 rotates, the eccentric shaft 28 rotates eccentrically with respect to the axis P of the rotating shaft 23. To do.
A drive bush 29 is fitted on the outer periphery of the eccentric shaft 28 so as to be relatively rotatable.
The drive bush 29 has an eccentric shaft 28 caused by the rotation of the rotary shaft 23 and a balance weight portion for adjusting an unbalance of the rotation caused by the eccentric rotation of the drive bush 29.

A movable scroll 19 is pivotally connected to the outer periphery of the drive bush 29 via a bearing 30.
The movable scroll 19 includes a disk-shaped movable side substrate 31 and a spiral movable side wall body 32.
The surface of the movable substrate 31 is disposed at a right angle to the axis P, and a spiral movable sidewall 32 is formed so as to protrude from the surface of the movable substrate 31 on the fixed scroll 18 side.

A plurality of bottomed circular holes 33 are formed near the periphery of the movable substrate 31, and a rotation prevention ring 34 is inserted into the bottomed circular hole 33.
A fixed side pin 27 is located at a position corresponding to the bottomed circular hole 33 of the shaft support member 22, and the fixed side pin 27 protrudes from the shaft support member 22 toward the bottomed circular hole 33, and a rotation prevention ring 34. Is inserted inside.
In the present embodiment, the rotation prevention ring 34 and the fixed side pin 27 constitute a rotation prevention mechanism that prevents the rotation (rotation) of the movable scroll 19.
For this reason, when the rotating shaft 23 rotates, the movable scroll 19 turns (revolves) around the axis P without rotating (spinning).

A fixed scroll 18 that meshes with the movable scroll 19 is fixed to the motor housing 14.
The fixed scroll 18 has a disk-shaped fixed side substrate 35 and a spiral fixed side wall body 36, and the fixed side substrate 35 and the fixed side wall body 36 are integrally formed.
The fixed side substrate 35 is disposed so as to close the end of the motor housing 14 on the opening side, and a spiral fixed side wall body 36 is formed so as to protrude from the surface of the fixed side substrate 35 on the movable scroll 19 side. . Note that the fixed-side substrate 35 forms a part of the motor housing 14.

In the electric compressor 10, the fixed side wall body 36 of the fixed scroll 18 and the movable side wall body 32 of the movable scroll 19 are brought into contact with each other, so that the compression chamber 20 is formed between the fixed side wall body 36 and the movable side wall body 32. The
As shown in FIG. 2, two compression chambers 20 having the same pressure and the same volume are formed at the same time. The refrigerant is introduced into the two outer compression chambers 20 through the suction port 26, and the two compression chambers 20 move from the outer peripheral side to the inner peripheral side (center side) by the turning of the movable scroll 19, so that the compression chamber is reduced due to the volume reduction. Twenty refrigerants are compressed.
A discharge port 37 is formed at the center of the fixed side substrate 35 of the fixed scroll 18, and the discharge port 37 is provided with a discharge valve 38 for opening and closing the discharge port 37 and a retainer 56. The discharge valve 38 opens when the pressure of the refrigerant compressed in the compression chamber 20 becomes equal to or higher than a predetermined pressure.

As shown in FIGS. 1 and 2, the fixed side substrate 35 has injection ports 39 that communicate with the compression chamber 20 and open to the valve block 15 side at two locations on the peripheral side in the radial direction from the discharge port 37. Is formed. The injection port 39 is a passage through which intermediate-pressure refrigerant is introduced into the compression chamber 20.
The injection port 39 is formed so as to communicate with the two compression chambers 20 during refrigerant compression. The movable scroll 19 side of the injection port 39 is formed with a smaller diameter than the valve block 15 side. This is for injecting the intermediate-pressure refrigerant introduced through the injection port 39 into the compression chamber 20, and the small diameter portion serves as a nozzle.

The electric motor 12 includes a stator 40 fixed to the inner peripheral surface of the motor housing 14 and a rotor 41 inserted into the stator 40 and fixed to the rotating shaft 23.
The electric compressor 10 includes a drive circuit case 65 joined to the motor housing 14. A drive circuit 64 for driving the electric motor 12 is installed in the drive circuit case 65.
Three-phase alternating current is supplied from the drive circuit 64 to the coil 40 </ b> A of the stator 40. The rotor 41 is rotationally driven by the electric power supplied to the coil 40 </ b> A of the stator 40 within the stator 40. As the rotor 41 rotates, the compression mechanism 11 connected to the rotating shaft 23 is operated.

As shown in FIGS. 1 and 3, the valve block 15 has a cylindrical shape and has a predetermined thickness in the axial direction. The valve block 15 is made of an aluminum metal material.
As shown in FIG. 3, the valve block 15 has a front surface 7 facing the motor housing 14, a rear surface 8 facing the discharge housing 16, and a peripheral wall 9 formed between the front surface 7 and the rear surface 8. ing.
As shown in FIGS. 3 and 4, a rectangular recess 42 that opens to the discharge housing 16 side is formed in the central portion of the valve block 15 in the radial direction. On the bottom side of the recess 42, a stepped portion 43 is formed between a large diameter portion with an increased inner diameter and a small diameter portion with a smaller inner diameter than the large diameter portion.
A muffler chamber (injection chamber) 45 is formed inside by covering the opening side of the recess 42 with the partition member 44. The muffler chamber 45 has a function of a muffler that reduces the pressure pulsation of the intermediate-pressure refrigerant introduced into the muffler chamber 45. The partition member 44 will be described in detail later.

As shown in FIG. 3, a check valve 46 is provided in the muffler chamber 45. The check valve 46 includes a valve plate 47 in which a through hole 47A is formed, a reed valve 48 disposed so as to close the through hole 47A, and a retainer 49 that restricts the movement of the reed valve 48. The check valve 46 is fixed to the stepped portion 43 with a bolt 50 in a state where the valve plate 47, the reed valve 48 and the retainer 49 are overlapped.
The muffler chamber 45 is divided into two by a check valve 46. A space located on the discharge housing 16 side with respect to the check valve 46 is denoted by S1, and a space located on the motor housing 14 side with respect to the check valve 46 is denoted by S2.

In the peripheral wall 9 of the valve block 15, an introduction port 51 is formed that communicates with the space S <b> 1 of the muffler chamber 45 and opens to the outer peripheral side.
The introduction port 51 is an introduction passage for introducing intermediate pressure refrigerant from an external refrigerant circuit (not shown), and the intermediate pressure refrigerant introduced through the introduction port 51 is introduced into the muffler chamber 45. The external refrigerant circuit includes a condenser and an evaporator, and a part of the refrigerant having an intermediate pressure reduced between the condenser and the evaporator is supplied to the introduction port 51 via a high-pressure guide pipe (not shown). Guided.
The intermediate pressure refrigerant means a refrigerant having a pressure higher than the suction pressure of the refrigerant sucked from the suction port 21 and lower than the discharge pressure of the refrigerant discharged from the discharge port 37.

Further, two supply ports 52 communicating with the injection port 39 formed in the fixed scroll 18 are formed at the peripheral edge portion of the bottom portion of the recess 42. The supply port 52 communicates with the space S2 of the muffler chamber 45.
When the intermediate pressure refrigerant is introduced into the space S1 of the muffler chamber 45 through the introduction port 51, the reed valve 48 moves in the direction in which the reed valve 48 is opened by the refrigerant pressure. As the check valve 46 is opened, the intermediate pressure refrigerant in the space S1 of the muffler chamber 45 is supplied to the compression chamber 20 through the space S2, the supply port 52 and the injection port 39 of the muffler chamber 45. At this time, the intermediate-pressure refrigerant is at a pressure higher than the compression chamber pressure in the compression chamber 20 at the supply position.
The introduction port 51, the muffler chamber 45 (S1), the muffler chamber 45 (S2), and the supply port 52 form a communication path that connects the introduction port 51 and the injection port 39, and communicates in the middle of the communication path. A muffler chamber 45 having a larger volume than the passage is provided.

On the opposite side (front surface 7 side) of the muffler chamber 45 in the valve block 15 to the axial direction, a recess 66 that opens to the discharge port 37 side is formed, and the recess 66 of the valve block 15 is covered with the fixed scroll 18 to discharge. A valve chamber 55 is formed.
A discharge valve 38 and a retainer 56 provided in the discharge port 37 are accommodated in the discharge valve chamber 55. Further, a passage 6 (see FIG. 1) that connects the discharge valve chamber 55 and the discharge chamber 58 is formed in the valve block 15.
A through hole 57 through which the bolt 17 is inserted is formed on the outer peripheral side of the valve block 15 in parallel with the axial direction. A plurality of through holes 57 are formed at equal intervals in the circumferential direction. The through hole 57 is formed at the same position in the circumferential direction as the screw hole 53 formed at the end of the motor housing 14. The through hole 57 corresponds to a bolt fastening hole.

  As described above, the valve block 15 includes the introduction port 51, the muffler chamber 45, the check valve 46, the supply port 52, and the like. The injection port 51, the muffler chamber 45, the check valve 46, the supply port 52, and the like constitute an injection mechanism. The injection mechanism refers to a mechanism that introduces a refrigerant having an intermediate pressure lower than the discharge pressure of the refrigerant discharged higher than the suction pressure of the sucked refrigerant into the compression chamber 20 in the middle of compression.

As shown in FIGS. 1 and 5, the discharge housing 16 is formed with a circular recess 62 that opens to the valve block 15 side. A protruding portion 73 that protrudes toward the valve block 15 (projects toward the partition member 44) is formed on the bottom side of the recess 62. By covering the recess 62 of the discharge housing 16 with the valve block 15, a discharge chamber 58 is formed inside.
A discharge port 60 that opens to the outer peripheral side is formed on the bottom side of the recess 62 in the discharge housing 16, and a discharge port 59 is formed at the outlet on the outer peripheral side of the discharge port 60. The discharge port 59 communicates with an external refrigerant circuit (not shown).
A communication passage 74 that connects the discharge chamber 58 and the discharge port 60 is formed at the center of the protrusion 73. The communication path 74 is formed parallel to the axial direction.
A through hole 61 through which the bolt 17 is inserted is formed on the outer peripheral side of the discharge housing 16 in parallel with the axial direction. A plurality of through holes 61 are formed at equal intervals in the circumferential direction. The through hole 61 is formed at the same position in the circumferential direction as the screw hole 53 formed at the end of the motor housing 14. The through hole 61 corresponds to a bolt fastening hole.

As shown in FIGS. 1 and 3, a partition member 44 is provided between the valve block 15 and the discharge housing 16. The discharge chamber 58 and the muffler chamber 45 are partitioned by joining the discharge housing 16 and the valve block 15 with the partition member 44 interposed therebetween. That is, the partition member 44 has a function of partitioning the muffler chamber 45 and the discharge chamber 58. Further, the muffler chamber 45 is disposed to face a part of the discharge chamber 58.
In addition, the partition member 75 shown with a dashed-two dotted line in FIG. 3 has shown the conventional flat partition member.

As shown in FIGS. 6 and 7, the partition member 44 has a box shape. The partition member 44 includes bottom plates 67 and 68 and a side wall 69 that covers the periphery. The side wall 69 is formed so as to extend from the bottom plates 67 and 68 toward the valve block 15, and the side wall 69 is surrounded by the discharge chamber 58. A step 77 is formed between the bottom plate 67 and the bottom plate 68. The bottom plates 67 and 68 and the side wall 69 of the partition member 44 are formed so as to enter (project) the discharge housing 16 side.
As shown in FIG. 3, when considering the distance from the end surface of the partition member 44 that contacts the rear surface 8 of the valve block 15, the distance L1 from the end surface of the bottom plate 67 and the distance L2 from the end surface of the bottom plate 68. The distance L1 is formed larger than the distance L2.
The bottom plate 68 is formed with an arc-shaped recess 71. The concave portion 71 includes a flat bottom portion 71A and a wall portion 71B that stands up around the bottom portion 71A.
Inside the partition member 44, a space S <b> 3 surrounded by the bottom plates 67 and 68, the step 77 and the side wall 69 is formed, and the space S <b> 3 communicates with the space S <b> 1 of the muffler chamber 45. That is, a part of the space S1 of the muffler chamber 45 is formed so as to enter the discharge housing 16 side.

Since the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58, the volume of the space S1 of the muffler chamber 45 is increased. As a material of the partition member 44, an aluminum-based metal material is used.
The partition member 44 is formed with attachment holes 70 at three locations around it. The partition member 44 is fixed to the valve block 15 by a bolt 54 inserted through the mounting hole 70.

  As shown in FIGS. 3 and 4, another recess 72 that opens to the discharge housing 16 side is formed on the discharge housing 16 side of the valve block 15 so as to surround the recess 42 on the outer peripheral side of the muffler chamber 45. Yes. As shown in FIG. 7, the recess 72 of the valve block 15 is covered with the discharge housing 16, so that the recess 72 communicates with the discharge chamber 58 and becomes a part of the discharge chamber 58. That is, the recess 72 enlarges the volume of the discharge chamber 58.

As shown in FIG. 7, if the opening on the side opposite to the discharge port 60 in the communication passage 74 is a protruding side opening 74A, the recess 71 provided in the bottom plate 68 of the partition member 44 covers the protruding side opening 74A. Has been placed. A predetermined gap is formed between the protruding side opening 74 </ b> A and the bottom 71 </ b> A of the recess 71. Further, a gap is formed between the outer peripheral surface 73A on the distal end side of the protruding portion 73 and the wall portion 71B. Thus, the cross-sectional area of the discharge passage from the discharge chamber 58 to the communication passage 74 can be reduced between the protruding side opening 74A and the recess 71. The size of the throttle (the size of the cross-sectional area of the discharge passage) can be adjusted by adjusting the depth of the recess 71 (the gap between the protrusion-side opening 74A and the bottom 71A).
The high-pressure refrigerant discharged into the discharge chamber 58 is sent to the discharge port 60 through the communication passage 74 after the passage cross-sectional area between the projecting side opening 74A and the recess 71 is reduced. It is discharged into the refrigerant circuit.

  The electric compressor 10 is assembled by preparing a valve block 15 in which the injection mechanism is integrated, arranging the valve block 15 so as to constitute a part of the housing 13 of the electric compressor, and arranging the valve block 15 in the motor housing 14. And the discharge housing 16 may be integrally fixed. That is, the valve block 15 may be disposed between the motor housing 14 and the discharge housing 16 and fixed integrally with the bolt 17.

Next, the operation of the electric compressor 10 having the above configuration will be described.
By supplying electric power from the drive circuit 64, the rotary shaft 23 is rotated, and this rotation is transmitted to the movable scroll 19 of the compression mechanism 11 via the eccentric shaft 28 and the drive bush 29. The movable scroll 19 performs a revolving orbiting motion while being prevented from rotating by the rotation preventing ring 34 and the fixed side pin 27 constituting the rotation preventing mechanism.
As the movable scroll 19 turns, the compression chamber 20 formed between the movable scroll 19 and the fixed scroll 18 moves from the outer peripheral side to the inner peripheral side (center side) to reduce the volume.

  For this reason, the refrigerant sucked into the motor housing 14 from the suction port 21 and introduced into the compression chamber 20 via the suction port 26 is compressed by the volume reduction of the compression chamber 20 and becomes high pressure. The discharge valve 38 is opened by the high-pressure refrigerant, and the refrigerant in the compression chamber 20 is discharged to the discharge valve chamber 55 through the discharge port 37 and sent from the discharge valve chamber 55 to the discharge chamber 58.

  By the way, when the intermediate pressure refrigerant is introduced from the external refrigerant circuit into the space S1 of the muffler chamber 45 through the introduction port 51, the reed valve 48 moves in the direction in which the reed valve 48 is opened by the refrigerant pressure. As the check valve 46 is opened, the refrigerant in the space S1 of the muffler chamber 45 is supplied to the compression chamber 20 in the middle of compression through the space S2, the supply port 52, and the injection port 39 of the muffler chamber 45. The At this time, the refrigerant pressure in the compression chamber 20 is lower than the intermediate refrigerant pressure.

The intermediate pressure refrigerant supplied to the compression chamber 20 is supplied to the compression chamber 20 after the pressure pulsation of the refrigerant is reduced in the muffler chamber 45 functioning as a muffler.
By the way, since the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58, the volume of the space S1 of the muffler chamber 45 is increased. Since the intermediate pressure refrigerant is introduced into the space S1 of the muffler chamber 45 having the increased volume, the pressure pulsation of the refrigerant can be efficiently reduced. In particular, the generation of noise associated with pressure pulsation can be suppressed. By supplying the intermediate-pressure refrigerant with reduced pressure pulsation to the compression chamber 20, the compression efficiency of the compressor is increased.
When the refrigerant pressure in the compression chamber 20 becomes higher than the intermediate refrigerant pressure in the muffler chamber 45, the check valve 46 is closed and supply of the intermediate pressure refrigerant to the compression chamber 20 is stopped. . Thus, the check valve 46 prevents the refrigerant from flowing back from the compression chamber 20.

The high-pressure refrigerant discharged into the discharge chamber 58 is sent to the discharge port 60 through the communication passage 74 after the passage cross-sectional area between the protrusion-side opening 74A and the recess 71 is reduced.
That is, the protrusion 73 is inserted into the recess 71 while maintaining a gap between the outer peripheral surface 73A on the tip end side of the protrusion 73 and the wall 71B, and the protrusion 74A of the communication path 74 and the bottom 71A of the recess 71 are inserted. A predetermined gap is formed between them. Therefore, the cross-sectional area of the discharge passage from the discharge chamber 58 to the communication passage 74 can be reduced between the protrusion-side opening 74A and the recess 71. As shown in an enlarged view in FIG. 7, the flow of the refrigerant flowing through the discharge passage from the discharge chamber 58 to the communication passage 74 is indicated by an arrow line. Therefore, it is possible to reduce pressure pulsation (hereinafter referred to as “discharge pulsation”) of the refrigerant discharged from the discharge chamber 58 to the discharge port 60. In particular, since the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58, the volume of the discharge chamber 58 may be reduced and the discharge pulsation may increase, but between the protruding side opening 74 </ b> A and the recess 71. By reducing the cross-sectional area of the discharge passage, discharge pulsation can be reduced.

The refrigerant discharged to the discharge port 60 is discharged to the external refrigerant circuit through the discharge port 59.
Although the volume of the discharge chamber 58 is reduced by forming the side wall 69 of the partition member 44 so as to be surrounded by the discharge chamber 58, the concave portion 72 provided in the valve block 15 is not part of the discharge chamber 58. Therefore, it is possible to compensate for the volume reduction of the discharge chamber 58.

The effect of the electric compressor 10 having the above configuration will be described.
Since the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58, the volume of the muffler chamber 45 functioning as a muffler is increased. Since the intermediate pressure refrigerant is introduced into the muffler chamber 45 having the increased volume, the function as the muffler can be improved, and the pressure pulsation of the refrigerant can be efficiently reduced. Further, by supplying the intermediate pressure refrigerant with reduced pressure pulsation to the compression chamber 20, it is possible to suppress a change in the amount of refrigerant supplied due to the pressure pulsation, and to further increase the compression efficiency of the compressor.

  The partition member 44 includes a bottom plate 67 having a large distance L1 from the end surface, a bottom plate 68 having a small distance L2 from the end surface, and a side wall 69 covering the periphery. Therefore, the volume of the muffler chamber 45 can be easily changed by changing the distance L1 of the bottom plate 67 and the distance L2 of the bottom plate 68. For example, FIG. 8 shows a partition member 76 in which the distance L1 of the bottom plate 67 is reduced. In this case, the increase in the volume of the muffler chamber 45 can be reduced. As described above, the distances L1 and L2 from the end faces of the bottom plates 67 and 68 can be easily changed according to the type of the vehicle on which the electric compressor 10 is mounted, and the refrigerant introduced into the muffler chamber 45 can be changed. Tuning of pressure pulsation can be performed. That is, the degree of freedom of volume setting is high, and the volume setting according to the conditions of the vehicle is possible.

  A valve block 15 in which the introduction port 51, the muffler chamber 45, the check valve 46, the supply port 52 and the like are gathered is prepared, and the motor housing 14, the valve block 15 and the discharge housing 16 are stacked, and the valve block 15 is the housing of the electric compressor. The valve block 15 may be fixed integrally with the motor housing 14 and the discharge housing 16 by arranging so as to constitute a part of the motor 13. Therefore, it is possible to easily add an injection mechanism.

  The protrusion 73 is inserted into the recess 71 while maintaining a gap between the outer peripheral surface 73A on the tip end side of the protrusion 73 and the wall 71B, and between the protrusion 74A of the communication path 74 and the bottom 71A of the recess 71. A predetermined gap is formed. Therefore, since the cross-sectional area of the discharge passage from the discharge chamber 58 to the communication passage 74 can be reduced between the protrusion side opening 74A and the recess 71, the pressure pulsation of the refrigerant discharged from the discharge chamber 58 to the discharge port 60 is reduced. Is possible. In particular, since the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58, the volume of the discharge chamber 58 may be reduced and the discharge pulsation may increase, but between the protruding side opening 74 </ b> A and the recess 71. By reducing the cross-sectional area of the discharge passage, discharge pulsation can be reduced. Further, by adjusting the depth of the concave portion 71 (the length between the bottom plate 68 and the bottom portion 71A), the gap between the protruding side opening 74A of the communication passage 74 and the bottom portion 71A of the concave portion 71 can be adjusted.

  Although the volume of the discharge chamber 58 is reduced by forming the side wall 69 of the partition member 44 so as to be surrounded by the discharge chamber 58, the discharge chamber 58 originally has a large space, and a valve block. 15 can be used as a part of the discharge chamber 58, so that the volume reduction of the discharge chamber 58 can be compensated.

The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the spirit of the invention. For example, the following modifications may be made.
In the above embodiment, the partition member 44 has been described as including the bottom plate 67 having a large distance L1, the bottom plate 68 having a small distance L2, and the side wall 69 covering the periphery, but the shape of the partition member 44 is The shape is not limited to this, and any shape may be used as long as the side wall 69 of the partition member 44 is formed so as to be surrounded by the discharge chamber 58. For example, the bottom plates 67 and 68 may be inclined, or the bottom plates 67 and 68 may be swelled in a dome shape. Further, it may be formed so as to partially enter (project) the discharge housing 16 rather than the entire surface.
In the above embodiment, the description has been made on the assumption that the partition member 44 is made of an aluminum-based metal material. However, a resin material or other metal material may be used. In particular, when a resin material is used, the natural frequency can be changed, and vibration of the partition member 44 due to the pressure pulsation of the refrigerant can be suppressed.
In the above embodiment, the partition member 44 is formed so as to enter (project) the discharge housing 16 side. However, a sufficient volume is secured in the muffler chamber 45, and the muffler chamber 45 functions as a muffler. If present, the partition member 44 may have a flat plate shape.
In the above embodiment, the valve block 15 constitutes the outer shell of the electric compressor 10. However, the present invention is not limited to this, and the valve block 15 is disposed inside the motor housing 14 or the discharge housing 16. Also good.

DESCRIPTION OF SYMBOLS 10 Electric compressor 11 Compression mechanism 12 Electric motor 13 Housing 14 Motor housing 15 Valve block (intermediate pressure housing)
16 Discharge housing 17 Bolt 18 Fixed scroll 19 Movable scroll 20 Compression chamber 21 Suction port 23 Rotating shaft 28 Eccentric shaft 37 Discharge port 39 Injection port 44 Partition member 45 Muffler chamber 46 Check valve 51 Inlet port 52 Supply port 53 Screw hole (bolt Fastening hole)
57, 61 Through hole (bolt fastening hole)
58 Discharge chamber 59 Discharge port 60 Discharge port 67, 68 Bottom plate 69 Side wall 71 Recess 72 Recess 73 Projection 74 Communication path 74A Projection side opening P Axle

Claims (5)

A motor housing having an electric motor and a compression mechanism for compressing refrigerant sucked by rotation of the electric motor, and a discharge housing having a discharge chamber for discharging refrigerant compressed in a compression chamber formed in the compression mechanism The compression mechanism is configured to introduce an intermediate pressure refrigerant, which is higher than the suction pressure of the sucked refrigerant and lower than the discharge pressure of the discharged refrigerant, into the compression chamber during compression from an external refrigerant circuit. An electric compressor provided with a port,
An introduction port for introducing the intermediate-pressure refrigerant from the external refrigerant circuit; a communication path that communicates the introduction port and the injection port is provided; and the volume is expanded in the middle of the communication path from the communication path. An intermediate pressure housing with a muffler chamber,
The intermediate pressure housing is disposed between the motor housing and the discharge housing;
The motor housing, the discharge housing, and the intermediate pressure housing are laminated, and bolt fastening holes are formed in the motor housing, the discharge housing, and the intermediate pressure housing, respectively, and the motor housing, the discharge housing, and the intermediate pressure housing are formed. The housing is integrally fixed by a bolt inserted into the bolt fastening hole,
The electric compressor according to claim 1, wherein the muffler chamber is disposed to face the discharge chamber, and a partition member that partitions the muffler chamber and the discharge chamber is provided.   2. The electric compressor according to claim 1, wherein the partition member includes a bottom plate and a side wall extending from the bottom plate toward the intermediate pressure housing, and the side wall is surrounded by the discharge chamber. 3. The electric compressor according to claim 1 , wherein a recess for enlarging the volume of the discharge chamber is formed on the outer peripheral side of the muffler chamber on the discharge housing side of the intermediate pressure housing. . The discharge housing is provided with a protrusion that protrudes toward the partition member, and a throttle is formed between the protrusion and the partition member. The electric compressor according to item. The projecting portion is formed with a communication passage communicating the discharge port and the discharge chamber, and the partition member is formed with a recess so as to cover the projecting side opening of the communication passage. The electric compressor according to claim 4 , wherein the throttle is formed between the concave portion and the concave portion .

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