JP2016090299A - Liquid detector, compressor, and air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a capacitance liquid detector which requires a small installation space and which can suppress breakage due to damage, a compressor having the liquid detector, and an air conditioner having the compressor.SOLUTION: A detection element part 10 of a liquid detection unit 1 is configured so that, a pair of electrode plates 40 are respectively attached to a part 31 of a corresponding conductive terminal 30 out of plural conductive terminal 30, and arranged in an overlapped state with a gap in a direction separating from a base 20. In addition, each of the pair of electrode plates 40 is arranged along a vertical direction in a housing, and when viewed from an upper side, each of the pair of electrode plates 40 is arranged along a side wall part of the housing.SELECTED DRAWING: Figure 2

Description

  The present invention relates to, for example, a capacitance type liquid detector used for detecting a liquid level of a lubricating oil of a compressor used in an air conditioner, a compressor having the liquid detector, and the compression The present invention relates to an air conditioner equipped with a machine.

  The air conditioner includes an outdoor heat exchanger and an indoor heat exchanger, and an expansion valve and a compressor provided therebetween. In the refrigeration cycle of an air conditioner, for example, the liquid refrigerant that has passed through the outdoor heat exchanger becomes gaseous by the expansion valve, and the temperature is lowered to cool air, which is led to the indoor heat exchanger. The gaseous refrigerant that has transferred heat (low temperature) to the indoor air by the indoor heat exchanger is compressed by the compressor to a high temperature / high pressure state, and heat (high temperature) is given to the outdoor air by the outdoor heat exchanger. It becomes liquid again by transferring.

  As a compressor used in such an air conditioner, there is a compressor adopting a rotary method or a scroll method. For example, in a rotary compressor disclosed in Patent Document 1, a compression unit having a cylinder in which a working chamber is formed and an annular piston accommodated in the working chamber is disposed in a tank-like compressor housing. The annular piston is rotated while a part of the outer peripheral surface is in contact with the peripheral wall surface of the working chamber, whereby the refrigerant introduced into the working chamber is compressed.

  In the compressor disclosed in Patent Document 1, lubricating oil is accommodated in the compressor housing for lubrication of sliding parts such as cylinders and pistons and sealing (sealing) of minute gaps. And if this lubricating oil becomes less than a predetermined amount for some reason, it will hinder the operation of the compressor, so it is necessary to monitor the amount of lubricating oil. For example, Patent Document 2 discloses a sensor that can be used for monitoring the amount of such lubricating oil.

  As shown in FIG. 18, the sensor disclosed in Patent Document 2 (indicated by reference numeral 901 in the figure) is parallel to the end portions of a pair of conductive pins 904 attached to the substrate body 902 with a space therebetween. A pair of arranged strip-shaped electrode plates 905 are attached. And since the electrostatic capacitance between the conductive pins 904 changes depending on the presence or absence of the lubricating oil between the pair of electrode plates 905, by providing this sensor 901 at an appropriate height in the compressor casing, It can be detected whether the amount is equal to or greater than a predetermined amount.

JP 2012-207585 A JP 2013-92491 A

  However, the above-described sensor 901 is attached to the side wall portion along the vertical direction in the compressor casing, and the pair of electrode plates 905 are arranged extending in the horizontal direction toward the inside of the compressor casing. Therefore, for example, (1) a pair of electrode plates 905 are arranged so as to largely protrude from the side wall portion to the inside of the compressor housing, and relatively to avoid interference with the compression portion and the like in the compressor housing. There is a problem that a large mounting space is required, and (2) the load concentrated on the portion where the conductive pin 904 is attached to the substrate body 902 is increased, and the portion may be damaged.

  Accordingly, the present invention provides an electrostatic capacity type liquid detector that has a small installation space and can suppress a failure due to breakage, a compressor having the liquid detector, and an air conditioner including the compressor. With the goal.

  In order to achieve the above object, the invention described in claim 1 is a capacitance type liquid detector used for detecting a liquid contained in a container, and is provided on a side wall portion of the container. A base attached to the side wall so as to close the through hole, a plurality of conductive terminals attached to the base so that at least a part thereof is disposed in the container, and a corresponding one of the plurality of conductive terminals And a plurality of electrode plates that are respectively attached to the part of the conductive terminals and arranged in parallel and spaced apart from each other in a direction away from the base. is there.

  The invention described in claim 2 is the invention described in claim 1, wherein the plurality of electrode plates are three or more.

  The invention described in claim 3 is the invention described in claim 1 or 2, wherein each of the plurality of electrode plates is disposed along the vertical direction in the container and viewed from above. It arrange | positions along a side wall part, It is characterized by the above-mentioned.

  The invention described in claim 4 is the invention described in claim 3, wherein the base has an attachment surface that comes into contact with the side wall portion so as to surround the through hole when the through hole is closed. Each of the electrode plates is parallel to the mounting surface.

  The invention described in claim 5 is the invention described in claim 3, wherein the through hole is formed in a circular shape in plan view, and the base is formed so as to be fitted into the through hole. It is a feature.

  The invention described in claim 6 is the invention described in any one of claims 1 to 5, wherein each of the plurality of electrode plates is formed in a disc shape or a regular polygon plate shape. It is characterized by this.

  The invention described in claim 7 is the invention described in any one of claims 1 to 6, wherein an electrode plate arranged closest to the base among the plurality of electrode plates is set to a reference potential. It is characterized by being connected.

  The invention described in claim 8 is the invention described in claim 7, wherein three or more of the plurality of electrode plates are provided, and the electrode plates disposed at both ends of the plurality of electrode plates, It is connected to a reference potential.

  In order to achieve the above object, the invention described in claim 9 is a liquid detection that detects a housing, a compression section provided in the housing, and lubricating oil contained in a container of the housing. It is a compressor which has a part, Comprising: The said liquid detection part is comprised including the liquid detector as described in any one of Claims 1-8, It is a compressor characterized by the above-mentioned.

  The invention described in claim 10 is an air conditioner including a refrigerant circuit including an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a compressor in order to achieve the above object, wherein the compressor Is an air conditioner comprising the compressor according to claim 9.

  According to the first, ninth, and tenth aspects of the present invention, the plurality of electrode plates are respectively attached to a part of the plurality of conductive terminals that are positioned in the container of the corresponding conductive terminals, and are separated from the base. Are arranged in parallel and spaced apart from each other. Since it did in this way, a some electrode plate does not protrude greatly inside a container, and the load concentrated on the part which attaches a conductive terminal to a base can be made small. As a result, the mounting space can be reduced, and failure due to breakage can be suppressed.

  According to the invention described in claim 2, the number of the plurality of electrode plates is three or more. Since it did in this way, since the group of the electrode plate which mutually faces can be increased compared with the structure which has several electrode plates, the electrostatic capacitance can be increased comparatively easily. Thereby, the detection accuracy of a liquid can be improved effectively.

  According to the invention described in claim 3, each of the plurality of electrode plates is disposed along the vertical direction in the container and disposed along the side wall portion of the container when viewed from above. Since it did in this way, the liquid tear (hardness of the remainder of a liquid) between several electrode plates can be improved, and detection accuracy can be improved.

  According to the invention described in claim 4, the base has a mounting surface that contacts the side wall portion so as to surround the through hole when the through hole is closed, and each of the plurality of electrode plates is parallel to the mounting surface. Has been. As a result, even when the mounting angle when the base is mounted on the container (the rotation angle with the through direction of the through-hole of the container as the rotation axis) varies, the plurality of electrode plates are surely in the vertical direction. It is arranged along. Therefore, it is possible to suppress variation in detection accuracy due to a difference in liquid breakage (hardness of remaining liquid) between the plurality of electrode plates.

  According to the invention described in claim 5, the through hole is formed in a circular shape in plan view, and the base is formed so as to be fitted into the through hole. Since it did in this way, since a through-hole is a planar view circular shape, a base can be attached at arbitrary attachment angles with a some electrode plate along a perpendicular direction. Therefore, it is possible to suppress variations in detection accuracy due to differences in the liquid breakage between the plurality of electrode plates.

  According to the invention described in claim 6, each of the plurality of electrode plates is formed in a disc shape or a regular polygon plate shape. For this reason, for example, in a configuration in which a plurality of electrode plates are formed in a band plate shape, an attachment angle when the base is attached to the container (a rotation angle with the through direction of the through hole of the container as the rotation axis) ) Varies, the height at which the liquid touches the plurality of electrode plates also varies, which may cause variations in detection accuracy. However, the plurality of electrode plates are disk-shaped or regular polygonal plate-shaped. As a result, the height at which the liquid contacts the plurality of electrode plates can be made substantially constant regardless of the mounting angle, and variations in detection accuracy can be suppressed.

  According to the invention described in claim 7, the electrode plate arranged closest to the base among the plurality of electrode plates is connected to the reference potential. As a result, the electrode plate arranged closest to the base among the plurality of electrode plates is connected to a reference potential such as a power supply potential or a ground (ground) potential, for example. The influence of stray capacitance (parasitic capacitance) can be suppressed, and detection accuracy can be improved.

  According to the invention described in claim 8, three or more electrode plates are provided, and the electrode plates arranged at both ends of the plurality of electrode plates are connected to the reference potential. As a result, the electrode plates arranged at both ends of the plurality of electrode plates are connected to a reference potential such as a power supply potential or a ground (ground) potential, for example, so that external noise and adjacent structures The influence of the stray capacitance (parasitic capacitance) between them can be suppressed, and the detection accuracy can be improved.

It is a front view of the liquid detection unit which has a detection element part concerning one embodiment of the present invention. It is sectional drawing which follows the XX line of FIG. It is a rear view of the detection element part which the liquid detection unit of FIG. 1 has. It is a front view of the detection control part which the liquid detection unit of FIG. 1 has. It is a figure which shows the outline of the electric circuit of the detection element part which the liquid detection unit of FIG. 1 has. It is a figure which shows the outline of the electric circuit of the liquid detection unit of FIG. It is sectional drawing which shows the structure of the 1st modification of the detection element part which the liquid detection unit of FIG. 1 has. It is a figure which shows the outline of the electric circuit of the detection element part of FIG. It is sectional drawing which shows the structure of the 2nd modification of the detection element part which the liquid detection unit of FIG. 1 has. FIG. 10 is a rear view of the detection element unit of FIG. 9. It is a figure which shows the outline of the electric circuit of the detection element part of FIG. It is sectional drawing which shows the structure of the 3rd modification of the detection element part which the liquid detection unit of FIG. 1 has. It is a front view of the detection element part of FIG. It is sectional drawing which shows the structure of the 4th modification of the detection element part which the liquid detection unit of FIG. 1 has. It is a perspective view of the detection element part of FIG. It is sectional drawing of the compressor which concerns on one Embodiment of this invention. It is a figure which shows schematic structure of the air conditioner which concerns on one Embodiment of this invention. It is a perspective view of the conventional liquid level sensor.

(Embodiment of liquid detector)
Hereinafter, a liquid detection unit having a liquid detector according to an embodiment of the present invention will be described with reference to FIGS. This liquid detection unit is a capacitance type, for example, is attached to a side wall portion of a casing of a compressor, which will be described later, and the level of lubricating oil contained in the casing and impurities to the lubricating oil Used to detect the degree of contamination.

  FIG. 1 is a front view of a liquid detection unit having a detection element unit according to an embodiment of the present invention. 2 is a cross-sectional view taken along line XX of FIG. FIG. 3 is a rear view of the detection element unit included in the liquid detection unit of FIG. FIG. 4 is a front view of a detection control unit included in the liquid detection unit of FIG. FIG. 5 is a diagram showing an outline of an electric circuit of a detection element unit included in the liquid detection unit of FIG. FIG. 6 is a diagram showing an outline of an electric circuit of the liquid detection unit of FIG.

  As shown in FIGS. 1 to 4, this liquid detection unit (indicated by reference numeral 1 in the figure) has a detection element unit 10 as a liquid detector and a detection control unit 50 (FIG. 2). . The detection element unit 10 and the detection control unit 50 are configured to be fitted to each other as a pair of connectors.

  The detection element unit 10 includes a base 20, a plurality of conductive terminals 30, and a pair of electrode plates 40.

  The base 20 is made of, for example, a metal such as stainless steel, and integrally includes a base main body portion 21, a cylindrical portion 22, and a flange portion 23, and a plurality of conductive materials described later. A hermetic glass 24 for fixing the terminal 30 is provided.

  The base main body 21 is formed in a disc shape. The cylindrical portion 22 is provided so as to protrude from one surface 21 a of the base body 21 so as to be coaxial with the base body 21. A plurality of through holes 21c penetrating the one surface 21a and the other surface 21b are formed at a location inside the cylindrical portion 22 in the base main body portion 21. The flange portion 23 is provided over the entire peripheral surface 21 d of the base main body portion 21 so as to protrude in the radial direction of the base main body portion 21. The attachment surface 23a facing the same direction as the other surface 21b of the base main body portion 21 in the flange portion 23 is an annular flat surface, and is attached to the case 102 of the compressor 101 to be described later. It surrounds the through-hole 103a provided in the part 103, and is arrange | positioned so that the whole may contact the outer surface of the said side wall part 103 closely. The hermetic glass 24 is fixed in the plurality of through holes 21c.

  The plurality of conductive terminals 30 are made of, for example, a conductive metal such as a nickel alloy, and are each formed in a rod shape that extends straight. In addition to this, the conductive terminal 30 may have a plate shape and the shape is arbitrary. Each of the plurality of conductive terminals 30 is inserted through the corresponding through hole 21c, and is fixedly attached to the base body 21 while being electrically insulated from the base body 21 by the hermetic glass 24. Yes. In order to fix the conductive terminal 30 to the base body portion 21, another insulating material may be used instead of the hermetic glass 24. Each of the plurality of conductive terminals 30 is arranged so that each part 31 protrudes perpendicularly from the other surface 21b of the base body 21 and the other part 32 protrudes perpendicularly from one surface 21a. The other part 32 of each conductive terminal 30 is brought into contact with the female terminal of the detection control unit 50 as a male terminal when fitted with the detection control unit 50 described later.

  In the present embodiment, six conductive terminals 30 are included, and two types of lengths are included. Specifically, three of the plurality of conductive terminals are formed long (indicated by reference numeral 30L in the figure), and the remaining three are formed shorter than these three (indicated by reference numeral 30S in the figure). . The three conductive terminals 30L and the remaining three conductive terminals 30S are alternately arranged in the circumferential direction so as to be the vertices of a regular hexagon as viewed from the front. The plurality of conductive terminals 30 (30L, 30S) are fixed to the base main body portion 21 so that the lengths of the other portions 32 thereof are the same, whereby one of the three conductive terminals 30L. The part 31 and the part 31 of the remaining three conductive terminals 30 </ b> S have different lengths.

  The pair of electrode plates 40 is made of, for example, a conductive metal such as stainless steel, and each is formed in the same flat disk shape. One electrode plate 40L of the pair of electrode plates 40 is fixedly attached to the tip of each of the three conductive terminals 30L described above, and the other electrode plate 40S includes the remaining three electrode plates 40S. Each conductive terminal 30S is fixedly attached to the tip of each part 31 thereof. A through hole 40a through which the three conductive terminals 30L are inserted is provided at a position corresponding to the three conductive terminals 30L in the other electrode plate 40S. Each through hole 40a is formed in such a size that the conductive terminal 30L and the electrode plate 40S do not contact each other. Each through hole 40a may be covered with an insulating material in a state where the conductive terminal 30L is inserted. Each electrode plate 40 is attached to each conductive terminal 30 by, for example, welding or brazing. Thus, by attaching one electrode plate 40L and the other electrode plate 40S to the respective tips of the part 31 of the conductive terminal 30L and the part of the conductive terminal 30S having different lengths, these electrode plates 40L, 40S is arranged in parallel with a space therebetween, that is, the plurality of electrode plates 40 are arranged side by side in parallel with each other in a direction away from the base 20. The electrode plates 40L and 40S are also arranged in parallel with the mounting surface 23a of the flange portion 23 (that is, made parallel).

  The detection control unit 50 includes a housing 60, a case 70, and a control board 80.

  The housing 60 is made of, for example, a synthetic resin, and integrally includes a housing main body 61, a cylindrical portion 62, and a substrate housing portion 63, and further includes a seal member 64. Yes.

  The housing main body 61 is formed in a disc shape. The cylindrical portion 62 is provided so as to protrude from one surface 61 a of the housing main body 61 so as to be coaxial with the housing main body 61. The cylindrical part 62 has an outer diameter substantially the same as the inner diameter of the cylindrical part 22 so that the cylindrical part 62 is accommodated in the cylindrical part 22 of the detection element part 10 when fitted, and its height is substantially equal to the depth of the cylindrical part 22. Are the same. The cylindrical portion 62 is formed with terminal holes 62b that open to locations corresponding to the plurality of conductive terminals 30 on the end face 62a and accommodate female terminals (not shown). The substrate housing portion 63 is provided on the other surface 61 b of the housing main body 61 so as to protrude in a square tube shape. The substrate accommodating portion 63 may be of any shape as long as it can accommodate a control substrate 80 to be described later, such as a cylindrical shape.

  The seal member 64 is formed in an annular shape using, for example, an elastic material such as rubber, and is partly exposed and embedded on one surface 61 a of the housing main body 61 so as to surround the cylindrical portion 22. The seal member 64 is crushed by the end surface 22a of the cylindrical portion 22 of the detection element unit 10 when fitted, and seals (seal) between the detection element unit 10 and the detection control unit 50.

  The case 70 is made of, for example, a synthetic resin, and integrally includes a cylindrical peripheral wall portion 71 and a bottom wall portion 72 that closes one end of the peripheral wall portion 71.

  The inner diameter of the peripheral wall 71 is substantially the same as the outer diameter of the cylindrical portion 22 so as to accommodate the cylindrical portion 22 of the detection element portion 10 when fitted. Further, a locking claw (not shown) that locks into a locking receiving hole (not shown) formed on the outer peripheral surface of the cylindrical portion 22 when fitted is formed on the inner peripheral surface of the peripheral wall portion 71 so as to protrude. Yes. The bottom wall portion 72 is formed with a fitting hole 72a formed in substantially the same shape (in the present embodiment, a square shape) as the planar view shape of the substrate housing portion 63 so that the substrate housing portion 63 can be fitted therein. Has been.

  The control board 80 is an electronic board in which various electronic components constituting a detection circuit for detecting capacitance are mounted on a printed board. The control board 80 is housed and fixed in the board housing portion 63, and is connected to a host control device (not shown) through the lead wire 85. The control board 80 is connected to a female terminal (not shown) accommodated in the terminal hole 62b, and in a state where the female terminal is in contact with the other part 32 (that is, a male terminal) of the conductive terminal 30, The capacitance between the electrode plates 40 is detected, and a detection signal corresponding to the capacitance is output through the lead wire 85. For example, the control board 80 detects a capacitance based on a time constant, a resonance frequency in a resonance circuit, and the like, and outputs a voltage signal (detection signal) that changes according to the magnitude of the capacitance.

  The detection element unit 10 and the detection control unit 50 are fitted closer to each other from the state shown in FIG. 2, so that the conductive terminal 30 (male terminal) of the detection element unit 10 and the housing 60 of the detection control unit 50 are included. The liquid detection unit 1 is configured to output a detection signal corresponding to the capacitance that changes in accordance with the liquid state between the pair of electrode plates 40. Here, the “liquid state” includes, for example, the ratio of impurities mixed in the liquid in addition to the presence or absence of the liquid.

  As shown in FIG. 5, the sensing element unit 10 can be regarded as a capacitor that stores electric charges between a pair of electrode plates 40. As shown in FIG. 6, the liquid detection unit 1 detects the capacitance between the pair of electrode plates 40, and outputs a detection signal corresponding to the detected capacitance. Based on this detection signal, the presence or absence of liquid at the height at which the detection element unit 10 is attached, that is, the liquid level can be detected. In addition, the ratio of impurities mixed in the liquid can be detected based on the capacitance value indicated by the detection signal.

  Next, the operation of the liquid detection unit 1 described above will be described.

  For example, as shown in FIG. 16, the detection element portion 10 of the liquid detection unit 1 is attached to a side wall portion 103 along a vertical direction in a casing 102 as a container of a compressor 101 described later. Specifically, a circular through hole 103a that is larger than the outer diameter of the base main body portion 21 of the detection element portion 10 and smaller than the outer diameter of the flange portion 23 is formed in the side wall portion 103 of the housing 102. A part 31 of the plurality of conductive terminals 30 and a pair of electrode plates 40 are inserted into the housing 102 from the through hole 103 a, and the entire mounting surface 23 a of the flange portion 23 is brought into contact with the outer surface of the side wall portion 103. And after welding the flange part 23 to the side wall part 103 and plugging up the through hole 103a, the detection control part 50 is fitted to the detection element part 10. In this embodiment, the entire mounting surface 23a of the flange portion 23 is in contact with the outer surface of the side wall portion 103. However, in addition to this, a surface opposite to the mounting surface 23a of the flange portion 23 is mounted. As a surface, it is good also as a structure which contact | abuts the said whole attachment surface to the inner surface of the side wall part 103. FIG.

  At this time, the pair of electrode plates 40 of the detection element unit 10 are arranged side by side so as to be spaced apart from each other in the direction away from the base 20, arranged along the vertical direction in the housing 102, and When viewed from the side, it is disposed along the side wall 103. Therefore, for example, the pair of electrode plates 40 protrudes inwardly of the housing 102 compared to the configuration in which the electrode plate 905 has a strip shape and extends toward the inside of the housing as in the conventional construction shown in FIG. In addition, the load concentrated on the portion of each conductive terminal 30 supported by the hermetic glass 24 is reduced. When the side wall portion 103 has a shape other than a linear shape such as an arc shape when viewed from above, the pair of electrode plates 40 may be disposed substantially along the extending direction.

  Further, the pair of electrode plates 40 and the mounting surface 23a of the flange portion 23 are arranged in parallel to each other. Therefore, even when the base 20 is attached to the side wall portion 103 while being shifted in the rotational direction around the axis, that is, when the attachment angle of the base 20 is shifted, the side wall portion 103 along which the mounting surface 23a extends along the vertical direction. Therefore, the pair of electrode plates 40 are also arranged along the vertical direction.

  Further, the pair of electrode plates 40 is formed in a disc shape. Therefore, for example, in the case of a configuration in which the pair of electrode plates 40 are formed in a band plate shape, when the base 20 is attached to the side wall portion 103 while being shifted in the rotational direction around the axis, that is, the base 20 If there is a deviation in the mounting angle, the height in contact with the liquid in the housing 102 will vary depending on the degree of deviation, but the disc-shaped configuration makes it possible to prevent the mounting from being displaced in the rotational direction. The height in contact with the liquid is constant.

  As described above, according to the present embodiment, the pair of electrode plates 40 are respectively attached to the corresponding portions 31 of the plurality of conductive terminals 30 and spaced apart from each other in the direction away from the base 20. Further, each of the pair of electrode plates 40 is disposed along the vertical direction in the housing 102 and disposed along the side wall portion 103 of the housing 102 when viewed from above. . As a result, the pair of electrode plates 40 does not protrude greatly inside the housing 102 and concentrates on the portion where the conductive terminal 30 is attached to the base 20, that is, the portion indicated by the hermetic glass 24. Load to be reduced. As a result, the mounting space can be reduced, and failure due to breakage can be suppressed.

  Each of the pair of electrode plates 40 is parallel to the attachment surface 23 a of the flange portion 23. Thus, even when there is a variation (shift) in the attachment angle when the base 20 is attached to the housing 102, the pair of electrode plates 40 are reliably arranged along the vertical direction. Therefore, it is possible to suppress variations in detection accuracy due to a difference in the liquid breakage (hardness of the remaining liquid) between the pair of electrode plates 40.

  Each of the pair of electrode plates 40 is formed in a disc shape. Thus, for example, in a configuration in which the pair of electrode plates 40 are formed in a band plate shape, if the mounting angle varies when the base 20 is mounted on the housing 102, the liquid is Since the heights in contact with the pair of electrode plates 40 also vary, there may be variations in detection accuracy. However, since the pair of electrode plates 40 are formed in a disk shape, the liquid is transferred to the pair of electrodes. The height in contact with the plate 40 can be made constant regardless of the mounting angle, and variations in detection accuracy can be suppressed.

  In the above-described embodiment, the configuration has a pair (two) of electrode plates 40, but the present invention is not limited to this. For example, as shown in FIG. 7, it is good also as the detection element part 10A of the structure which has the four electrode plates 40. FIG. In this detection element portion 10A, two electrode plates 40L1 and 40L2 are attached to the three conductive terminals 30L, and two electrode plates 40S1 and 40S2 are attached to the remaining three conductive terminals 30S. FIG. 8 shows an outline of an electric circuit of the detection element unit 10A.

  Alternatively, for example, as illustrated in FIGS. 9 and 10, a detection element unit 10 </ b> B having a configuration including three electrode plates 40 may be used. The detection element unit 10B has nine conductive terminals 30 and includes three types of lengths. That is, three of the plurality of conductive terminals are formed long (indicated by reference numeral 30L in the figure), the other three from these three are formed short (indicated by reference numeral 30M in the figure), and the remaining three terminals Is further shortened (indicated by reference numeral 30S in the figure). The conductive terminals 30L, 30M, and 30S are sequentially arranged in the circumferential direction so as to be the apexes of a regular hexagon as viewed from the front. The plurality of conductive terminals 30 (30L, 30M, 30S) are fixed to the base body 21 so that the lengths of the other portions 32 thereof are the same, whereby the respective conductive terminals 30L, 30M are fixed. , 30S have different lengths 31 from each other. One electrode plate 40L among the three electrode plates 40 is fixedly attached to the tip of each of the three conductive terminals 30L described above, and the other one electrode plate 40M is: The other three conductive terminals 30M are fixedly attached to the tips of the respective parts 31, and the remaining one electrode plate 40S is attached to the tips of the respective parts 31 of the remaining three conductive terminals 30S. It is fixedly attached to. Thereby, a space is provided between the electrode plate 40L and the electrode plate 40M, and between the electrode plate 40M and the electrode plate 40S, and they are arranged in parallel to each other. FIG. 11 shows an outline of an electric circuit of the detection element unit 10B.

  By adopting a configuration having three or more electrode plates 40 as in the detection element units 10A and 10B, the number of sets of electrode plates 40 facing each other is increased as compared with a configuration having two electrode plates 40. Therefore, the capacitance can be increased relatively easily. Thereby, the detection accuracy of a liquid can be improved effectively.

  In the above-described embodiment, each electrode plate 40 is formed in a disk shape. However, the present invention is not limited to this, and the electrode plate 40 is arbitrary in shape and size. . However, from the viewpoint of suppressing variation in height at which the liquid contacts the plurality of electrode plates 40, that is, suppressing variation in detection accuracy, the electrode plate 40 is formed in a disc shape, a regular triangle plate shape, a square plate shape, or a regular hexagon shape. It is preferably formed in a regular polygonal plate shape such as a square plate shape or a regular octagonal plate shape.

  In the above-described embodiment, the mounting surface 23a of the flange portion 23 of the base 20 is welded in a state of being in contact with the outer surface of the side wall portion 103 of the compressor 101. However, the present invention is not limited to this. Absent. For example, the configuration in which the flange portion 23 is omitted and the peripheral portion of the other surface 21b of the base main body portion 21 of the base 20 is welded in a state of being in contact with the outer surface of the side wall portion 103 of the compressor 101, or Unless the side wall portion 103 and the base 20 are fixed with a screw structure and sealed with a flare seal structure, the base 20 is attached to the side wall portion 103 so as to close the through hole 103a of the side wall portion 103. If it is the structure which fixes and attaches, attachment structure is arbitrary.

  In the above-described embodiment, the conductive terminal 30 is arranged horizontally and the electrode plate 40 is attached so as to be perpendicular to the conductive terminal 30 along the vertical direction. However, the present invention is not limited to this. is not. For example, even when attached to a side wall portion that is not parallel to the vertical direction, the shape of the conductive terminal 30 and the angle formed by the conductive terminal 30 and the electrode plate 40 are appropriately set so that the plurality of electrode plates 40 are along the vertical direction. A set configuration may be used.

  In the above-described embodiment, each of the electrode plates 40 is supported by the three conductive terminals 30, but the present invention is not limited to this. For example, as shown in FIGS. 12 and 13, a sensing element unit 10 </ b> C configured to support each electrode plate 40 with one conductive terminal 30 may be used. In this detection element portion 10 </ b> C, two conductive terminals 30 are fixedly attached to the base body portion 21. The portions 31 of these conductive terminals 30 are arranged horizontally (in the left-right direction in the figure) at intervals. Each of the plurality of electrode plates 40 is disposed along the vertical direction. A group of electrode plates 40 (40L) out of the plurality of electrode plates 40 are juxtaposed in parallel with each other between the two conductive terminals 30 in the horizontal direction, and one of the peripheral edges is one side. It is fixedly attached to a part 31 of the conductive terminal 30 (30L). In addition, another group of electrode plates 40 (40S) among the plurality of electrode plates 40 are juxtaposed in parallel with each other between the two conductive terminals 30 so as to be spaced apart from each other in the horizontal direction. The portion is fixedly attached to a part 31 of the other conductive terminal 30 (30S). The group of electrode plates 40L and the other group of electrode plates 40S are alternately arranged so as to mesh with each other. The outline of the electric circuit of the detection element unit 10C is the same as that shown in FIG. By doing in this way, the number of the conductive terminals 30 can be reduced and it can be set as a simpler structure. However, the configuration in which the electrode plate 40 is supported by the plurality of conductive terminals 30 is more advantageous in terms of durability because the load applied to the portion where the conductive terminals 30 are attached to the base 20 can be dispersed.

  In the embodiment described above, the detection element unit 10 is configured to connect the electrode plate 40S closest to the base 20 of the two electrode plates 40L and 40S to a reference potential such as a power supply potential or a ground potential. It is desirable. That is, each conductive terminal 30 </ b> S is configured to be connected to the reference potential in the detection control unit 50 when the detection element unit 10 is connected to the detection control unit 50. By doing in this way, the influence of the stray capacitance (parasitic capacitance) etc. which arises between the electrode plate 40S near the base 20 and the base 20 can be suppressed, and detection accuracy can be improved. The same applies to a configuration in which three or more electrode plates 40 are provided.

  Further, in the configuration having three or more electrode plates 40, it is desirable to connect the electrode plates 40 arranged at both ends to a reference potential such as a power supply potential or a ground potential. For example, in the configuration shown in FIG. 12, the conductive terminal 30S is connected to the ground potential. By doing so, the influence of external noise and stray capacitance (parasitic capacitance) generated between adjacent structures such as the casing 102 or the base 20 of the compressor 101 can be suppressed, and detection accuracy can be improved. Further improvement can be achieved.

  In the above-described embodiment, each of the plurality of electrode plates 40 is provided independently. However, the present invention is not limited to this. For example, as shown in FIGS. 14 and 15, a sensing element unit 10 </ b> D having a configuration in which a part of the electrode plate 40 is included in a cylindrical electrode body 400 that is a cylindrical structure may be used. The cylindrical electrode body 400 included in the detection element unit 10D integrally includes a cylindrical peripheral wall portion 41 and electrode plates 40 (40L, 40K) that block both ends of the peripheral wall portion. In the cylindrical electrode body 400, another electrode plate 40 (40S) is accommodated. The electrode plates 40 are arranged side by side in parallel with a space therebetween. The conductive terminal 30 (30S) connected to the other electrode plate 40S is inserted through a through hole 40a provided in the electrode plate 40L. The electrode plate 40L and the other electrode plate 40S of the cylindrical electrode body 400 correspond to the electrode plate of the present invention. The electrode plate 40K can store an electrode between the other electrode plate 40S and the electrode plate 40L, and can also store charges between the electrode plate 40K connected to the electrode plate 40L via the peripheral wall portion 41. . Even in such a configuration, the same effects as those of the above-described embodiment can be obtained.

  In the above-described embodiment, the entire attachment surface 23 a of the flange portion 23 of the base 20 is brought into contact with the peripheral edge of the through hole 103 a on the outer surface of the side wall portion 103, but is not limited thereto. For example, the through hole 103a of the side wall 103 of the compressor 101 may be formed in a circular shape in plan view, and the base 20 may be fitted into the through hole 103a. Specifically, for example, the outer peripheral surface of the cylindrical portion 22 of the base 20 is formed in a tapered shape that gradually decreases in diameter toward the end surface 22a, and the end surface 22a side end portion of the outer peripheral surface has a diameter. The diameter of the through hole 103a is smaller than that of the through hole 103a and the diameter of the opposite end is larger than the diameter of the through hole 103a. Then, by inserting the cylindrical portion 22 into the through hole 103a from the inside of the housing 102, the cylindrical portion 22 and the through hole 103a are fitted at the same diameter as the through hole 103a on the outer peripheral surface of the cylindrical portion 22. . At this time, the through-hole 103a is circular in plan view, and the cylindrical section 22 that fits into the through-hole 103a is also circular in cross-section. Therefore, the base 20 can be mounted at any mounting angle (the through-direction of the through-hole 103a is rotated). It can be attached at a rotation angle as a shaft. By doing in this way, since the through-hole 103a is circular in planar view, the base 20 can be attached at an arbitrary attachment angle while the plurality of electrode plates 40 are along the vertical direction. Therefore, it is possible to suppress variations in detection accuracy due to a difference in liquid breakage between the plurality of electrode plates 40.

  In the above-described embodiment, the plurality of electrode plates 40 are fixedly attached to the conductive terminals 30 fixed to the base 20, and the positional relationship between the electrode plates 40 and the attachment surface 23a of the flange portion 23 is fixed. However, the present invention is not limited to this, and it is only necessary that they are arranged in parallel. For example, each of the plurality of electrode plates 40 is supported by one conductive terminal 30 at one edge, and is attached to be swingable by adopting a hinge structure between the electrode plate 40 and the conductive terminals 30. May be. By doing in this way, the electrode plate 40 hangs down on the conductive terminal 30, and is arranged parallel to each other along the vertical direction by gravity, and is also arranged in parallel with the mounting surface 23a (that is, made parallel).

  Moreover, in embodiment mentioned above, although the detection element part 10 and the detection control part 50 were separate bodies, and these were comprised so that fitting was possible as a pair of connector, it is not limited to this, Detection The liquid detection unit which comprised the element part 10 and the detection control part 50 integrally may be sufficient. In this configuration, the liquid detection unit corresponds to a liquid detector.

(Embodiment of compressor)
Hereinafter, a compressor according to an embodiment of the present invention will be described with reference to FIG. FIG. 16 is a cross-sectional view of a compressor according to an embodiment of the present invention. This compressor is provided in a refrigerant circuit of an air conditioner, for example, and is used for circulation of the refrigerant in the refrigerant circuit.

  The compressor 101 employs a rotary system and is housed in a housing 102 in a motor unit 110 having a motor stator 111 and a motor rotor 112, a cylinder 121, and a working chamber 122 formed in the cylinder 121. And a compression portion 120 having an annular piston 125. The motor rotor 112 and the annular piston 125 are connected by a crankshaft 130. Further, a lubricating oil K for lubricating the compression unit 120 and the like is accommodated in the housing 102. The housing 102 (specifically, the lower portion of the housing 102) corresponds to a container.

  When the crankshaft 130 is rotated by the motor unit 110, the compressor 101 is rotated while the annular piston 125 is in contact with the peripheral wall surface of the working chamber 122. In accordance with the rotation of the annular piston 125, the refrigerant is introduced into the working chamber 122 from the suction pipe 141 through the suction muffler 142 and the introduction pipe 143. Then, the refrigerant is compressed by the annular piston 125 in the working chamber 122 and led out of the compressor 101 through the discharge muffler 144, the casing 102, and the discharge pipe 145.

  The compressor 101 has the liquid detection unit 1 described above as a liquid detection unit. The detection element unit 10 of the liquid detection unit 1 is attached to the lower part of the side wall part 103 along the vertical direction in the housing 102. Specifically, in the detection element unit 10, a part 31 of the plurality of conductive terminals 30 and a pair of electrode plates 40 are inserted into a through hole 103 a provided in the side wall unit 103, and the flange portion 23 of the base 20 is formed. The flange portion 23 is fixed by welding in a state where the entire mounting surface 23a is in contact with the outer surface of the side wall portion 103 around the through hole 103a. The base 20 of the detection element unit 10 seals and closes the through hole 103a.

  The pair of electrode plates 40 of the detection element unit 10 are arranged in parallel to each other along the vertical direction in the housing 102 and arranged along the side wall part 103. In the normal state where the lubricant oil K is in an appropriate amount, the detection element unit 10 sinks below the liquid level in a normal state, and a part of the pair of electrode plates 40 in the abnormal state where the lubricant oil K is insufficient. It is arrange | positioned so that the whole may be exposed on a liquid level.

  As mentioned above, according to this embodiment, since it has the liquid detection unit 1 mentioned above, while being able to reduce the attachment space of the detection element part 10, it can suppress the failure by breakage, therefore, it is small and has few failures. can do.

  In the above-described embodiment, the rotary system is used. However, the present invention is not limited to this. For example, a structure using another system such as a scroll system may be used.

(Embodiment of air conditioner)
Below, the air conditioner which concerns on one Embodiment of this invention is demonstrated with reference to FIG. FIG. 17 is a diagram illustrating a schematic configuration of an air conditioner according to an embodiment of the present invention. This air conditioner is used, for example, as an air conditioner provided in a house or a commercial facility.

  The air conditioner 201 includes a refrigerant circuit 210 including an indoor heat exchanger 211, an outdoor heat exchanger 212, an expansion valve 213, the compressor 101 described above, and a flow path switching valve 215.

  The flow path of the refrigeration cycle of the air conditioner 201 is switched to two flow paths of “cooling mode” and “heating mode” by the flow path switching valve 215. In the cooling mode, as indicated by a solid line arrow in FIG. 17, the refrigerant compressed by the compressor 101 flows from the flow path switching valve 215 into the outdoor heat exchanger 212 and into the expansion valve 213. Then, the refrigerant is expanded by the expansion valve 213 and flows into the indoor heat exchanger 211. The refrigerant that has flowed into the indoor heat exchanger 211 flows into the compressor 101 via the flow path switching valve 215. On the other hand, in the heating mode, the refrigerant compressed by the compressor 101 flows into the indoor heat exchanger 211 from the flow path switching valve 215 and flows into the expansion valve 213 as indicated by broken arrows in FIG. Then, the refrigerant is expanded by the expansion valve 213 and circulated in the order of the outdoor heat exchanger 212, the flow path switching valve 215, and the compressor 101.

  In the cooling mode, the outdoor heat exchanger 212 functions as a condenser, the indoor heat exchanger 211 functions as an evaporator, and indoor cooling is performed. In the heating mode, the outdoor heat exchanger 212 functions as an evaporator, the indoor heat exchanger 211 functions as a condenser, and the room is heated. In the air conditioner 201, the flow path switching valve 215 may be omitted, and only one of the cooling mode and the heating mode may be provided.

  As described above, according to the present embodiment, since the compressor 101 having the liquid detection unit 1 described above is provided, the air conditioner 201 with a small size and few failures can be obtained.

  In addition, embodiment mentioned above only showed the typical form of this invention, and this invention is not limited to embodiment. That is, those skilled in the art can implement various modifications in accordance with conventionally known knowledge without departing from the scope of the present invention. Of course, such modifications are included in the scope of the present invention as long as the liquid detector, the compressor and the air conditioner of the present invention are provided.

1 Liquid detection unit 10, 10A, 10B, 10C, 10D Detection element part (liquid detector)
20 Base 23a Mounting surface 24 Hermetic glass 30 Conductive terminal 31 Part of conductive terminal 32 Other part of conductive terminal 40 Electrode plate 50 Detection control unit 101 Compressor 102 Housing (container)
DESCRIPTION OF SYMBOLS 103 Side wall part 103a Through-hole 201 Air conditioner 210 Refrigerant circuit 211 Indoor heat exchanger 212 Outdoor heat exchanger 213 Expansion valve 215 Channel switching valve K Lubricating oil

Claims (10)

A capacitance type liquid detector used for detecting liquid contained in a container,
A base attached to the side wall so as to close a through hole provided in the side wall of the container;
A plurality of conductive terminals attached to the base such that at least a portion thereof is disposed in the container;
A plurality of electrode plates that are respectively attached to the corresponding ones of the plurality of conductive terminals and arranged in parallel and spaced apart from each other in a direction away from the base. A liquid detector characterized by comprising:   The liquid detector according to claim 1, wherein the number of the plurality of electrode plates is three or more.   The each of the plurality of electrode plates is disposed along the vertical direction in the container and is disposed along the side wall when viewed from above. Liquid detector. The base has an attachment surface that contacts the side wall portion so as to surround the through hole when the through hole is closed;
The liquid detector according to claim 3, wherein each of the plurality of electrode plates is parallel to the mounting surface. The through hole is formed in a circular shape in plan view;
The liquid detector according to claim 3, wherein the base is formed so as to be fitted into the through hole.   6. The liquid detector according to claim 1, wherein each of the plurality of electrode plates is formed in a disc shape or a regular polygon plate shape.   The liquid detector according to claim 1, wherein an electrode plate disposed closest to the base among the plurality of electrode plates is connected to a reference potential. Three or more electrode plates are provided,
The liquid detector according to claim 7, wherein electrode plates disposed at both ends of the plurality of electrode plates are connected to a reference potential. A compressor having a casing, a compression section provided in the casing, and a liquid detection section that detects lubricating oil contained in a container of the casing;
The said liquid detection part is comprised including the liquid detector as described in any one of Claims 1-8, The compressor characterized by the above-mentioned.   It is an air conditioner provided with the refrigerant circuit containing an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a compressor, Comprising: The said compressor is comprised with the compressor of Claim 9. Air conditioner.

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