JP2011074910A - Linear electric compressor and refrigerant circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a linear electric compressor which can achieve further miniaturization while maintaining a compression capacity of a refrigerant per unit time highly, and a refrigerant circuit which is provided with the linear electric compressor. <P>SOLUTION: A piston 27 which is provided at the linear electric compressor 100 comprises: a piston rod 29; and first and second piston heads 31, 33 which are integrally provided at both ends of the piston rod 29. The piston rod 29 has a smaller diameter than those of the first and second piston heads 31, 33. A permanent magnets 35, 37 are provided at the first and second piston heads 31, 33. A center housing 7 has a spring seat 7b between the first and second piston heads 31, 33, and there are provided the first and second coils 49, 51 located around the piston rod 29 between the spring seat 7b and the first and second piston heads 31, 33. In addition, the refrigerant circuits 200, 300 are provided with the linear electric compressor 100. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a linear electric compressor and a refrigeration circuit.

  FIG. 11 and the like in Patent Document 1 disclose a linear electric compressor in which a double-headed piston having a piston head at both ends of a piston rod is employed and a compression chamber is formed at both ends of the piston. In this linear electric compressor, permanent magnets are provided in the piston rod and each piston head, which are the central part of the double-headed piston, and a coil is provided around the piston rod and each piston head. This linear electric compressor has a pair of springs inside the piston rod of the double-headed piston.

  In this linear electric compressor, by periodically supplying power to the coil, an electromagnetic force that periodically changes around the coil is generated, and the permanent magnet of the piston is attracted to or separated from the electromagnetic force. For this reason, the piston reciprocates in the cylinder bore. At this time, the piston reciprocates also by resonance due to the natural frequency of the spring. By the reciprocation of the piston, the refrigerant is sucked into the compression chamber from the suction chamber, compressed in the compression chamber, and then discharged to the discharge chamber. For this reason, since these linear electric compressors can perform the compression action of the refrigerant by electric control, it is considered that they can be adopted as an air conditioner for an electric vehicle or the like.

  Further, in this linear electric compressor, since the refrigerant can be compressed twice during one reciprocation of the piston, unit time is compared with a linear electric compressor in which a compression chamber is formed only at one end of the piston. The compression capacity of the hit refrigerant can be increased, and downsizing is also realized.

Japanese Patent No. 3953735

  However, in the conventional linear electric compressor, it is necessary to secure a space for arranging the spring inside the piston rod. For this reason, the outer diameter of the piston rod is increased, and the inner diameter of the cylinder bore must be designed according to the outer diameter of the piston rod. For this reason, there is a limit to downsizing of the linear electric compressor beyond a certain level.

  The present invention has been made in view of the above-described conventional situation, and provides a linear electric compressor capable of realizing further downsizing while maintaining a high compression capacity of the refrigerant per unit time. Is a problem to be solved. Moreover, providing the refrigeration circuit provided with this linear electric compressor is also made into the subject which should be solved.

The linear electric compressor of the present invention is provided between a housing in which a cylinder bore extends in the axial direction, a pair of end plates joined to both ends of the housing, and between the cylinder bore and each end plate, The cylinder bore side is a compression chamber, each end plate side is a discharge chamber and / or a suction chamber, and the cylinder bore is reciprocally accommodated in the cylinder bore, and the compression unit is interposed between the valve units. A piston forming a chamber, a biasing member having a biasing force for reciprocating the piston in the cylinder bore, a coil provided in the housing, and an electromagnetic force provided by the piston and generated by the coil. A permanent magnet that reciprocates the piston together with the force member,
The piston is composed of a piston rod and a pair of piston heads that are integrally provided at both ends of the piston rod and slidably contact the cylinder bore.
The piston rod is smaller in diameter than both piston heads;
The permanent magnet is provided on both the piston heads, and the coil is provided around both the piston heads,
The housing has a spring seat between the piston heads;
The biasing member positioned around the piston rod is provided between the spring seat and the piston heads (Claim 1).

  In the linear electric compressor according to the present invention, since the double-headed piston having the piston heads at both ends of the piston rod is employed, the refrigerant can be compressed twice during one reciprocation of the piston. The compression capacity of the hit refrigerant can be increased.

  In this linear electric compressor, in addition to the electromagnetic force generated by the coil, the piston can be reciprocated by resonance due to the natural frequency of the biasing member. Moreover, since it is not necessary to provide this urging member in the compression chamber, a large compression chamber can be secured. Further, since the biasing member does not have a larger diameter than the piston head, the inner diameter of the cylinder bore can be designed according to the outer diameter of the piston head.

  Therefore, the linear electric compressor of the present invention can realize further downsizing while maintaining a high compression capacity of the refrigerant per unit time.

  In this linear electric compressor, since permanent magnets are provided on both piston heads and coils are provided around both piston heads, electromagnetic force and permanent magnets act on both ends of the pistons on both heads. For this reason, both ends of the piston are less likely to swing in the radial direction during reciprocating motion, and the piston head is less likely to interfere with the cylinder bore.

  In the valve unit, each end plate side may be a discharge chamber and a suction chamber, or a discharge chamber or a suction chamber. When each end plate side is a discharge chamber, a suction chamber can be provided in the piston. When each end plate side is a suction chamber, a discharge chamber can be provided in the piston.

  In the linear electric compressor according to the present invention, the housing preferably includes a cylinder block having a cylinder bore extending therethrough, and a shell that is provided outside the cylinder block and holds a coil between the cylinder block and the cylinder block. Item 2). In this case, it is possible to easily provide a coil between the cylinder block and the shell, and the manufacture of the linear electric compressor can be facilitated.

  An intermediate chamber communicating between both piston heads may be formed between one or both of the cylinder block and the shell. In addition, each valve unit can have a discharge chamber on each end plate side. Each piston head is preferably provided with a suction valve mechanism having an intermediate chamber as a suction chamber. In this case, a discharge chamber is formed on each end plate side, and a suction chamber is formed in the piston. For this reason, this linear electric compressor can be reduced in size and the weight of the piston can be reduced, and the compression capacity of the refrigerant can be maintained high.

  The suction valve mechanism may be a float type or a lead type.

  The refrigeration circuit of the present invention includes a linear electric compressor, a condenser, an expansion valve, an evaporator, a pipe for connecting these to circulate a refrigerant, and the coil of the linear electric compressor. A power supply device that supplies power; a detection unit that can detect a state quantity of the linear electric compressor; and a control device that controls the power supplied by the power supply device based on a detection signal of the detection unit. (Claim 4).

  Since this refrigeration circuit includes the linear electric compressor described above, it is possible to achieve downsizing while having high air conditioning capability.

  Further, for example, it is possible to prevent the piston head from colliding with the valve unit. That is, in the linear electric compressor, not only when the voltage or current value of the power supplied to the coil is increased, but also when the cycle of the voltage or current is maintained at a constant value, The load such as the pressure of the refrigerant changes. Then, the distance that the piston reciprocates, that is, the stroke of the piston, is changed by the thrust generated by the predetermined electric power. For example, when the heat load is small and the pressure of the refrigerant in the compression chamber is reduced, the piston head collides with the valve unit, which causes an increase in operating noise and vibration of the linear electric compressor. In this case, the durability of the linear electric compressor is reduced. In this regard, in the refrigeration circuit of the present invention, the detection means detects the state quantity of the linear electric compressor. And a control apparatus controls the electric power which a electric power feeder supplies with the detection signal of a detection means. For this reason, an electric power feeder supplies the electric power based on a state quantity with respect to a linear electric compressor. For this reason, in this refrigeration circuit, it is possible to prevent the piston head from colliding with the valve unit. Further, in this refrigeration circuit, it is possible to increase the durability by reducing the load as appropriate based on the state quantity of the linear electric compressor.

  The state quantity of this linear electric compressor can be various. For example, it may be a physical quantity based on the position of a piston, a refrigerant discharged from a linear electric compressor, or a pressure or temperature of a refrigerant sucked into the linear electric compressor. In addition, the plurality of state quantities can be combined.

  The state quantity is preferably a physical quantity based on the position of the piston in the linear electric compressor. In this case, it is possible to directly prevent the piston head from colliding with the valve unit.

  This physical quantity may be, for example, the position of the piston for each detection time. This physical quantity can be directly grasped by, for example, a position sensor using laser or magnetism, an operating transformer, a proximity switch, or the like. In addition, the physical quantity can be indirectly grasped by grasping the flow rate of the refrigerant flowing through the linear electric compressor or the pipe using a flow sensor or the like.

  This physical quantity is preferably a differential pressure between a first pressure that is the pressure of the refrigerant flowing through the first position and a second pressure that is the pressure of the refrigerant flowing through the second position downstream of the first position ( Claim 6). In this case, the control device can grasp the flow rate of the refrigerant flowing through the linear electric compressor or the pipe by grasping the differential pressure between the first pressure and the second pressure detected by the detecting means. . And the control apparatus can grasp | ascertain the suitable position where a piston should grasp | ascertain, for example, grasp | ascertains the position of the present piston, reversely calculates the drive frequency of the piston. And since an electric power feeder supplies electric power so that a piston exists in an appropriate position, a piston will not collide with a valve unit.

  In this refrigeration circuit, the detection means is provided in a pipe, and the detection means has a permanent magnet, and a movable body that can be moved by a differential pressure between the first pressure and the second pressure, and the magnetic flux density of the permanent magnet. It is preferable to have a magnetic force detection device capable of detection. In this case, the differential pressure between the first pressure and the second pressure in the pipe can be detected by the change in the magnetic flux density. For this reason, the influence of the magnetic flux by the coil etc. of a linear electric compressor is not produced. In addition, the flow rate of the refrigerant flowing in the pipe can be detected with high accuracy while being relatively inexpensive.

  In this refrigeration circuit, the first position and the second position are set in a pipe located between the discharge chamber of the linear electric compressor and the condenser, and there is a throttle portion between the first position and the second position. (Claim 8). In this case, the throttle unit can cause a loss in the refrigerant pressure upstream and downstream of the throttle unit, and the detection means can detect the refrigerant differential pressure. If the throttle part is provided in the pipe between the discharge chamber of the linear electric compressor and the condenser, that is, the position where the high-pressure refrigerant flows, the refrigeration circuit itself even if the refrigerant pressure is lost by the throttle part The performance will not be degraded.

  In this refrigeration circuit, a bent portion may be provided between the first position and the second position (claim 9). In this case, based on the flow path resistance of the refrigerant flowing through the bent portion, the detection means can detect the differential pressure of the refrigerant upstream and downstream of the bent portion. Since the bent portion is inevitably formed, the flow rate of the refrigerant in the pipe can be detected easily and efficiently by providing the detecting means at the bent portion. This bent portion may be in a state bent to such an extent that a flow path resistance is generated with respect to the refrigerant. In addition, since the pressure loss of the refrigerant caused by the flow path resistance due to the bent portion is considered to be slight, the bent portion may be provided at a position where the high-pressure refrigerant flows, or provided at a position where the low-pressure refrigerant flows. May be.

1 is a cross-sectional view showing a linear electric compressor of Example 1. FIG. 1 is a schematic structural diagram showing a refrigeration circuit using the linear electric compressor of Example 1. FIG. It is sectional drawing which expands and shows a part of linear electric compressor of Example 1. FIG. It is explanatory drawing which shows the coil and permanent magnet in the linear electric compressor of Example 1. FIG. 6 is a schematic structural diagram showing a refrigeration circuit of Example 2. FIG. It is an expanded sectional view of a flow sensor etc. concerning Example 2. 6 is a schematic structural diagram showing a refrigeration circuit of Example 3. FIG. It is an expanded sectional view of a flow sensor etc. concerning Example 3.

  Embodiments 1 to 3 embodying the present invention will be described below with reference to the drawings. The linear electric compressor 100 of the first embodiment and the refrigeration circuits 200 and 300 shown in the second and third embodiments are employed as air conditioners for hybrid vehicles and electric vehicles.

Example 1
As shown in FIG. 1, the linear electric compressor 100 includes a housing 9 including first and second cylinder blocks 1 and 3, a shell 5 and a center housing 7. A first cylinder bore 1a extends through the first cylinder block 1 in the axial direction, and a second cylinder bore 3a extends through the second cylinder block 3 in the axial direction. The first and second cylinder bores 1a and 3a are designed to be coaxial and have the same diameter.

  The first and second cylinder blocks 1 and 3 have flanges 1b and 3b around the first and second cylinder bores 1a and 3a, and are accommodated in the shell 5 so that the flanges 1b and 3b are located at both ends. . In the shell 5, a center housing 7 is provided between the first and second cylinder blocks 1 and 3. The center housing 7 is provided with a receiving hole 7a that is coaxial with and has the same diameter as the first and second cylinder bores 1a and 3a.

  First and second end plates 11 and 13 are joined to both ends of the shell 5 via first and second gaskets 10 and 12. A space is formed in the first and second end plates 11, 13. A first valve plate 15 is sandwiched between the first gasket 10 and the first end plate 11, and the second gasket 12 and the second end are sandwiched between the first gasket 10 and the first end plate 11. A second valve plate 17 is sandwiched between the plate 13. The spaces of the first and second end plates 11 and 13 are defined as first and second discharge chambers 11a and 13a by first and second valve plates 15 and 17, respectively. The first and second end plates 11 and 13 are provided with first and second discharge ports 11b and 13b. The first discharge chamber 11a is connected to the pipe 101 shown in FIG. 2 by the first discharge port 11b, and the second discharge chamber 13a is connected to the pipe 102 by the second discharge port 13b.

  As shown in FIG. 3, the first valve plate 15 is provided with a discharge port 15 a. Further, on the first discharge port 11 b side of the first valve plate 15, a lead type discharge valve 19 that can open and close the discharge port 15 a and a retainer 21 that regulates the opening degree of the discharge valve 19 are provided by a rivet 23. ing. The first valve plate 15, the discharge valve 19, the retainer 21, and the rivet 23 are the first valve unit 25. The same applies to the second valve plate 17 side.

  As shown in FIG. 1, pistons 27 are accommodated in the first and second cylinder bores 1a, 3a and the accommodation hole 7a so as to be reciprocally movable. The piston 27 is provided integrally with the piston rod 29, one end of the piston rod 29, the first piston head 31 slidably contacting the inside of the first cylinder bore 1a, and the other end of the piston rod 29. The second piston head 33 is in sliding contact with the cylinder bore 3a.

  As shown in FIGS. 3 and 4, the first piston head 31 is provided integrally with a head main body 39 that fixes permanent magnets 35 and 37 on the outer peripheral surface, and the head main body 39, and is formed on the inner surface of the first cylinder bore 1 a. On the other hand, the first and second spacers 41 and 43 that separate the outer peripheral surfaces of the permanent magnets 35 and 37 are provided.

  The permanent magnets 35 and 37 are cylindrical. The permanent magnets 35 and 37 are made of rare earth magnets. The permanent magnet 35 has an N pole on the outer peripheral surface side and an S pole on the inner peripheral surface side, and the permanent magnet 37 has an S pole on the outer peripheral surface side and an N pole on the inner peripheral surface side. The permanent magnet 35 may have an S pole on the outer peripheral surface side and an N pole on the inner peripheral surface side, and the permanent magnet 37 may have an N pole on the outer peripheral surface side and an S pole on the inner peripheral surface side.

  The second spacer 43 is press-fitted into the head main body 39, then the permanent magnets 37 and 35 are inserted into the head main body 39, and then the first spacer 41 is press-fitted into the head main body 39, so that the permanent magnets 35 and 37 become the head main body. 39 is sandwiched between first and second spacers 41 and 43. The first piston head 31 has a compression chamber 45 on the first spacer 41 side.

  As shown in FIG. 3, the head body 39 is provided with a suction port 39 a that opens from the inside toward the compression chamber 45. The first spacer 41 is formed with a valve port 41a communicating with the suction port 39a, and a float type suction valve 47 is accommodated in the valve port 41a. The valve port 41a has a locking piece 41b on the compression chamber 45 side. On the outer peripheral edge of the suction valve 47, there are formed a plurality of locking pieces 47a that come into contact with the locking piece 41b when the suction port 39a is opened, and notches 47b are formed between the locking pieces 47a.

  As shown in FIG. 1, a first piston head 31 and a second piston head 33 are press-fitted into both ends of the piston rod 29. The piston rod 29 has a smaller diameter than the first and second piston heads 31 and 33. The piston rod 29 is formed with a suction passage 29a that opens radially in the center and extends in the axial direction. As shown in FIG. 3, the suction passage 29 a communicates with the suction port 39 a of the first piston head 31. The suction passage 29a, the suction port 39a, the suction valve 47, and the first spacer 41 constitute a suction valve mechanism 50. The same applies to the second piston head 33 side.

  As shown in FIG. 1, a spring seat 7b is formed in the center housing 7 at a central position at the same distance from the end faces of the first and second cylinder blocks 1 and 3 so as to protrude into the storage hole 7a. Yes. A space between the inner surface of the storage hole 7a and the outer peripheral surface of the piston rod 29 is a spring chamber 7c. First and second coil springs 49 and 51 as urging members are accommodated in the spring chamber 7c.

  In the pre-compressed state, the first coil spring 49 has one end abutting against the spring seat 7 b and the other end abutting against the second spacer 43 of the first piston head 31. Similarly, the second coil spring 51 is in a pre-compressed state, and has one end abutting against the spring seat 7 b and the other end abutting against a second spacer (no symbol) of the second piston head 33.

  An intermediate chamber 53 is formed between the center housing 7 and the shell 5. The center housing 7 has a communication hole 7d penetrating the intermediate chamber 53 and the spring chamber 7c. The intermediate chamber 53 and the spring chamber 7 c correspond to the suction chamber 55. The shell 5 is provided with a suction port 5a. The suction chamber 55 is connected to the pipe 103 shown in FIG. 2 by a suction port 5a. A cover 57 for closing the intermediate chamber 53 is also fixed to the shell 5, and terminals (not shown) connected to coils 63 a, 63 b, 65 a, 65 b described later are fixed to the cover 57.

  Coils 63 a, 63 b, 65 a, 65 b are provided between the first and second cylinder blocks 1, 3 and the shell 5 while being held by the first and second holding members 59, 61. The coils 63a, 63b, 65a, 65b are provided around the first and second piston heads 31, 33. The first and second cylinder blocks 1 and 3 and the first and second holding members 59 and 61 are made of a magnetic material. The first and second cylinder blocks 1 and 3 can also be made of a nonmagnetic material.

  As shown in FIG. 2, the linear electric compressor 100 has a pipe 101 and a pipe 102 connected to a pipe 104, and the pipe 104 is connected to a condenser 105. The condenser 105 is connected to the expansion valve 107 and the evaporator 108 by a pipe 106, and the evaporator 108 is connected to the pipe 103. The terminal in the intermediate chamber 53 is connected to the power feeding device 110 by a lead wire 109. The power feeding device 110 is electrically controlled. These constitute a refrigeration circuit.

  In the linear electric compressor 100 configured as described above, the power feeding device 110 periodically feeds the coils 63a, 63b, 65a, and 65b to periodically change around the coils 63a, 63b, 65a, and 65b. To generate electromagnetic force. At this time, as shown in FIG. 4, if the coil 63 a attracts the permanent magnet 35 of the first piston head 31, the coil 63 b tries to separate the permanent magnet 37 of the first piston head 31. Conversely, if the coil 63 a pulls away the permanent magnet 35 of the first piston head 31, the coil 63 b tries to attract the permanent magnet 37 of the first piston head 31. For this reason, the piston 27 reciprocates in the first and second cylinder bores 1a and 3a. At this time, the piston 27 reciprocates also by resonance due to the natural frequency of the first and second coil springs 49 and 51.

  By the reciprocating motion of the piston 27, the respective steps of refrigerant suction, compression, and discharge are performed. The first piston head 31 side will be described in detail as an example. As shown in FIG. 3, when the first piston head side 31 is in the suction stroke, the pressure in the compression chamber 45 becomes low, the suction valve 47 moves in the valve port 41, and the suction port 39a is opened. For this reason, the refrigerant in the suction chamber 55 passes through the gap between the notch 47b of the suction valve 47 and the locking piece 41b from the suction port 39a and is sucked into the compression chamber 45. At this time, the discharge port 15 a is closed by the discharge valve 19.

  When the first piston head side 31 shifts to the compression stroke, the suction valve 47 moves in the valve port 41a by the pressure in the compression chamber 45, and the suction port 39a is closed. And when the pressure in the compression chamber 45 rises, the discharge valve 19 is opened. That is, the first piston head side 31 shifts to the discharge stroke. Thus, the compressed refrigerant is discharged to the discharge chamber 11a through the discharge port 15a. Although the refrigerant in the discharge chamber 11a is hot, the gasket 10 exists between the first end plate 11 and the first cylinder block 1, and the piston 27 is not in direct contact with the discharge chamber 11a. For this reason, the piston 27 is hardly heated by the refrigerant in the discharge chambers 11a and 13a. The same applies to the second piston head 33 side.

  In this way, the refrigerant circulates as follows to air-condition the vehicle interior. That is, the refrigerant discharged from the evaporator 108 to the pipe 103 is sucked into the compression chamber 45 from the suction chamber 55, compressed in the compression chamber 45, and then discharged into the first and second discharge chambers 11a and 13a. The refrigerant in the first and second discharge chambers 11 a and 13 a reaches the condenser 105, the expansion valve 107 and the evaporator 108 through the pipes 101 and 102. Since this linear electric compressor 100 can perform a refrigerant compression action by electric control, it can be suitably air-conditioned as an air conditioner for an electric vehicle or the like. For example, even if the vehicle is equipped with a hybrid engine and the engine is stopped while the vehicle is stopped, the linear electric compressor 100 can provide suitable air conditioning.

  Further, in this linear electric compressor 100, since the refrigerant can be compressed twice while the piston 27 reciprocates once, compared with the linear electric compressor that forms a compression chamber only at one end of the piston, The refrigerant compression capacity per unit time can be increased.

  Furthermore, this linear electric compressor 100 has first and second coil springs 49 and 51 at the center of the double-headed piston 27. The piston rod 29 has a smaller diameter than the first and second piston heads 31 and 33. Further, first and second coil springs 49 and 51 are housed in a spring chamber 7c having the same diameter as the first and second cylinder bores 1a and 3a. For this reason, in this linear electric compressor 100, it is not necessary to provide an urging member in the compression chamber 45, and a large compression chamber 45 can be secured. Further, since the first and second coil springs 49 and 51 do not have a larger diameter than the first and second piston heads 31 and 33, the first and second cylinder bores 1a according to the outer diameter of the first and second piston heads 31 and 33. The inner diameter of 3a and the inner diameter of the storage hole 7a of the center housing 7 can be designed.

  Therefore, the linear electric compressor 100 can achieve further downsizing while maintaining a high compression capacity of the refrigerant per unit time. In addition, by providing the linear electric compressor 100, the refrigeration circuit can be downsized while having high air conditioning capability.

  In particular, in the linear electric compressor 100, the first and second piston heads 31 and 33 are provided with permanent magnets 35 and 37, and the coils 63a, 63b, 65a and 65b are provided around the first and second piston heads 31 and 33. Therefore, the electromagnetic force and the permanent magnets 35 and 37 act at both ends of the double-headed piston 27. For this reason, both ends of the piston 27 are unlikely to swing in the radial direction during reciprocation, and the first and second piston heads 31 and 33 are unlikely to interfere with the first and second cylinder bores 1a and 3a.

  Further, in this linear electric compressor 100, since the housing 9 includes the first and second cylinder blocks 1, 3 and the shell 5, the linear electric compressor 100 is provided between the first and second cylinder blocks 1, 3 and the shell 5. The coils 63a, 63b, 65a, and 65b can be easily provided and can be easily manufactured.

  Further, in this linear electric compressor 100, an intermediate chamber 53 is formed between the first and second cylinder blocks 1, 3 and the shell 5, and each valve unit 25 is connected to the first and second end plates 11, 13 side first. The first and second piston heads 31 and 33 are provided with a suction valve mechanism 50. For this reason, the spring chamber 7c, which is a part of the suction chamber 55, and the suction passage 29a are formed in the piston 27. For this reason, the linear electric compressor 100 can be miniaturized, the weight of the piston 27 can be reduced, and the refrigerant compression capacity can be maintained high.

(Example 2)
As shown in FIG. 5, the refrigeration circuit 200 of the second embodiment includes a pipe 150 instead of the pipe 104 in the refrigeration circuit (see FIG. 2) shown in the first embodiment. The refrigeration circuit 200 further includes a flow sensor 111 and a control device 112 as detection means.

  As shown in FIG. 6, the pipe 150 is provided with a throttle portion 70 inside. In the refrigeration circuit 200, the first position 150 a is set upstream of the throttle unit 70, and the second position 150 b is set downstream of the throttle unit 70. That is, in the pipe 150, the refrigerant circulates in the direction from the first position 150a to the second position 150b, that is, in the arrow direction shown in FIG. Further, the upstream flow path 120 is connected to the first position 150a, and the downstream flow path 121 is connected to the second position 150b.

  The flow sensor 111 is provided in the pipe 150, and calculates a differential pressure between the first pressure P1 that is the pressure of the refrigerant flowing through the first position 150a and the second pressure P2 that is the pressure of the refrigerant that flows through the second position 150b. Detect. The flow sensor 111 includes a main body 71 and a Hall IC 73 as a magnetic force detection device.

  A spool 75 as a movable body is accommodated in the main body 71 so as to be movable up and down. A permanent magnet 77 is fixed to the spool 75. A spring seat 79 is fixed to the lower end of the main body 71. A first spring 81 is provided between the spring seat 79 and the spool 75 to urge the spool 75 upward. A second spring 83 that biases the spool 75 downward is provided between the inner upper surface of the main body 71 and the spool 75.

  An upstream flow path 120 is connected to the main body 71 at a position above the spool 75, and a downstream flow path 121 is connected to the spring seat 79. As a result, if the second pressure P2 is higher than the first pressure P1, the spool 75 is pushed upward inside the main body 71 against the biasing force of the second spring 83. On the contrary, if the second pressure P2 is lower than the first pressure P1, the spool 75 is pushed downward against the urging force of the first spring 81 inside the main body 71.

  The Hall IC 73 is fixed to the upper surface of the main body 71. The Hall IC 73 detects the magnetic flux density based on the permanent magnet 77 that approaches or is remote from the vertical movement of the spool 75. As shown in FIG. 5, the Hall IC 73 is electrically connected to the control device 112 via the control circuit 130. The Hall IC 73 transmits a detection signal based on the detected magnetic flux density toward the control device 112.

  The control device 112 includes a stroke calculation unit 113 and a voltage / frequency control unit 114. In addition, the control device 112 is electrically connected to the power feeding device 110 via the control circuit 131.

  The stroke calculation unit 113 grasps the current position of the piston 27 (see FIG. 1) based on the detection signal received from the Hall IC 73, that is, the flow rate of the refrigerant flowing in the pipe 150. The position of the piston 27 is a state quantity of the linear electric compressor 100. The stroke calculation unit 113 reversely calculates the drive frequency of the piston 27 and grasps an appropriate position where the piston 27 should be located. The stroke calculation unit 113 shown in FIG. 5 transmits a control signal based on the state quantity to the voltage / frequency control unit 114.

  Based on the control signal received from the stroke calculation unit 113, the voltage / frequency control unit 114 controls the power supply device 110 with respect to the voltage and current values of the electric power supplied to the linear electric compressor 100 and the cycle of the current. . The voltage / frequency control unit 114 individually determines the electric power supplied to the linear electric compressor 100 by the power supply device 110, that is, the voltage and current values and the current cycles applied to the coils 63a, 63b, 65a, and 65b. It is possible to control. Other configurations in the refrigeration circuit 200 are the same as those in the refrigeration circuit shown in the first embodiment, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.

  In the refrigeration circuit 200 configured as described above, the supply device 110 supplies the linear electric compressor 100 with electric power controlled based on the state quantity. In this refrigeration circuit 200, the state quantity of the linear electric compressor 100 is detected by detecting a physical quantity based on the position of the piston 27 (see FIG. 1) in the linear electric compressor 100. Thus, the electric power supplied to the linear electric compressor 100 is controlled based on the state quantity. For this reason, even when the heat load is reduced and the pressure of the refrigerant in the compression chamber 45 of the linear electric compressor 100 is reduced, the piston heads 31 and 33 are prevented from colliding with the valve units 15 and 17. it can. For this reason, in this refrigeration circuit 200, the durability of the linear electric compressor 100 can be increased.

  Further, the flow rate sensor 111 provided in the refrigeration circuit 200 can detect a differential pressure between the first pressure P1 and the second pressure P2 in the pipe 150 by changing the magnetic flux density. For this reason, it is possible to detect the flow rate of the refrigerant flowing through the pipe 150 with high accuracy while being relatively inexpensive. Moreover, since the flow sensor 111 is provided in the pipe 150, the influence of magnetic flux by the coils 63a, 63b, 65a, 65b, etc. of the linear electric compressor 100 does not occur.

  Further, in the refrigeration circuit 200, the throttle unit 70 is provided in the pipe 104 through which the high-pressure refrigerant flows. For this reason, even if a loss occurs in the refrigerant pressure by the throttle unit 70, the performance of the refrigeration circuit 200 itself does not deteriorate. Other functions and effects are the same as those of the refrigeration circuit shown in the first embodiment.

(Example 3)
As shown in FIG. 7, in the refrigeration circuit 300 according to the third embodiment, unlike the refrigeration circuit 200 according to the second embodiment (see FIG. 5), a flow sensor 111 is provided at the bent portion 90 of the pipe 103. Further, in this refrigeration circuit 300, instead of the pipe 150 of the refrigeration circuit 200 of the second embodiment, a pipe 104 is provided as in the refrigeration circuit shown in the first embodiment. That is, the refrigeration circuit 300 is not provided with the throttle unit 70.

  As shown in FIG. 8, in the refrigeration circuit 300, the first position 103 a is set upstream of the bent portion 90 of the pipe 103, and the second position 103 b is set downstream of the bent portion 90. That is, the refrigerant circulates in the pipe 103 from the first position 103a to the second position 103b, that is, in the direction of the arrow shown in FIG. Further, an upstream flow path 120 is connected to the first position 103a, and a downstream flow path 121 is connected to the second position 103b. Other configurations are the same as those of the refrigeration circuit 200 of the second embodiment, and the same components are denoted by the same reference numerals and detailed description thereof is omitted.

  In the refrigeration circuit 300 configured as described above, the flow sensor 111 can detect the differential pressure between the first pressure P1 and the second pressure P2 based on the flow path resistance of the refrigerant flowing through the bent portion 90. Become. In the refrigeration circuit 300, the flow rate of the refrigerant in the pipe 103 can be detected easily and efficiently by providing the flow rate sensor 111 in the bent portion 90 inevitably formed for mounting on the vehicle. . The bent portion 90 is not limited to a state bent at a substantially right angle as shown in FIG. 8 but may be in a state bent to such an extent that a flow path resistance is generated with respect to the refrigerant. Further, the bent portion 90 may be provided at a position where the high-pressure refrigerant flows, for example, the pipe 104. Other functions and effects are the same as those of the refrigeration circuit 200 of the second embodiment.

  In the above, the present invention has been described with reference to the first to third embodiments. However, the present invention is not limited to the first to third embodiments, and can be appropriately modified and applied without departing from the spirit of the present invention. Needless to say.

  For example, the linear electric compressor 100 according to the first embodiment may be used in combination with another compressor in addition to the case where the linear electric compressor 100 is used alone. The same applies to the refrigeration circuits 200 and 300 of the second and third embodiments.

  The first and second spacers 41 and 43 can also be made of a fluororesin such as PTFE. In this case, the piston 27 preferably slides in the first and second cylinder bores 1a and 3a.

  Further, the suction valve mechanism 50 may employ a lead type suction valve.

  Further, a position sensor, an operating transformer, a proximity switch, or the like using a laser or magnetism may be employed as the detection means, and the position of the piston 27 may be directly detected.

  A plurality of flow sensors 111 may be provided in the pipes 101 to 104 (150) and 106. Furthermore, in addition to the flow sensor 111, a pressure sensor, a temperature sensor, or the like may be used to detect the state of the refrigerant flowing in the linear electric compressor 100 and the pipes 101 to 104 (150) and 106 in more detail. In this case, the stroke calculation unit 113 can calculate the physical quantity with higher accuracy.

  The present invention can be mounted on an electric vehicle using an electric motor in addition to a hybrid vehicle. Moreover, it cannot be overemphasized that it can mount in the motor vehicle using an engine.

DESCRIPTION OF SYMBOLS 1a, 3a ... Cylinder bore 9 ... Housing (1 ... 1st cylinder block, 3 ... 2nd cylinder block, 5 ... Shell, 7 ... Center housing)
11, 13 ... End plate (11 ... First end plate, 13 ... Second end plate)
45 ... Compression chamber 11a, 13a ... Discharge chamber (11a ... First discharge chamber, 13a ... Second discharge chamber)
55 ... Suction chamber (7c ... Spring chamber, 53 ... Intermediate chamber)
25 ... Valve unit 27 ... Piston 49, 51 ... Biasing member (49 ... First coil spring, 51 ... Second coil spring)
63a, 63b, 65a, 65b ... Coil 35, 37, 77 ... Permanent magnet 29 ... Piston rod 31, 33 ... Piston head (31 ... First piston head, 33 ... Second piston head)
7b ... Spring seat 49, 51 ... Coil spring (49 ... First coil spring, 51 ... Second coil spring)
DESCRIPTION OF SYMBOLS 100 ... Linear electric compressor 50 ... Suction valve mechanism 105 ... Condenser 107 ... Expansion valve 108 ... Evaporator 101-104, 150, 106 ... Piping 110 ... Feeding device 200, 300 ... Refrigeration circuit 111 ... Flow rate sensor (detection means) )
112 ... Control device (113 ... Stroke calculation unit, 114 ... Voltage / frequency control unit)
103a, 150a ... first position 103b, 150b ... second position 75 ... spool (movable body)
73 ... Hall IC (Magnetic force detection device)
70: Restriction part 90 ... Bending part

Claims (9)

A housing in which a cylinder bore extends in an axial direction, a pair of end plates joined to both ends of the housing, a cylinder bore and each end plate are provided, and the cylinder bore side serves as a compression chamber. A pair of valve units having a discharge chamber and / or a suction chamber on the end plate side, a piston that is reciprocally accommodated in the cylinder bore, and forms a compression chamber between the valve units; And a permanent member for reciprocating the piston together with the biasing member by electromagnetic force generated by the coil, provided in the piston, by a biasing member having a biasing force for reciprocating the piston. With a magnet,
The piston is composed of a piston rod and a pair of piston heads that are integrally provided at both ends of the piston rod and slidably contact the cylinder bore.
The piston rod is smaller in diameter than both piston heads;
The permanent magnet is provided on both the piston heads, and the coil is provided around both the piston heads,
The housing has a spring seat between the piston heads;
A linear electric compressor, wherein the biasing member positioned around the piston rod is provided between the spring seat and the piston heads.   The linear electric compressor according to claim 1, wherein the housing includes a cylinder block in which the cylinder bore is provided, and a shell that is provided outside the cylinder block and holds the coil between the cylinder block. . An intermediate chamber communicating between the piston heads is formed between one of the cylinder block and the shell, or between them.
Each of the valve units has the end plate side as the discharge chamber,
3. A linear electric compressor according to claim 2, wherein each piston head is provided with a suction valve mechanism having the intermediate chamber as the suction chamber.   The linear electric compressor according to any one of claims 1 to 3, a condenser, an expansion valve, an evaporator, a pipe that connects these to circulate a refrigerant, and the linear electric compressor A power supply device that supplies power to the coil, a detection unit that can detect a state quantity of the linear electric compressor, and a control device that controls the power supplied by the power supply device according to a detection signal of the detection unit. A refrigeration circuit characterized by that.   The refrigeration circuit according to claim 4, wherein the state quantity is a physical quantity based on a position of the piston in the linear electric compressor.   The physical quantity is a differential pressure between a first pressure that is a pressure of the refrigerant that flows through a first position and a second pressure that is a pressure of the refrigerant that flows through a second position downstream of the first position. Item 6. The refrigeration circuit according to Item 5. The detection means is provided in the pipe,
The detection means includes a permanent magnet, a movable body that can move by a differential pressure between the first pressure and the second pressure, and a magnetic force detection device that can detect the magnetic flux density of the permanent magnet. The refrigeration circuit according to claim 6.   The first position and the second position are set in the pipe located between the discharge chamber of the linear electric compressor and the condenser, and between the first position and the second position The refrigeration circuit according to claim 7, further comprising a throttle portion.   The refrigeration circuit according to claim 7, wherein a bent portion is provided between the first position and the second position.

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