JP2012098016A - Evaporator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an evaporator for reducing the amount of oil contained in a refrigerant from staying in a tank disposed below.SOLUTION: In a downwind lower tank 41, which is one of the lower tanks 41 of the evaporator 1, the internal space of the downwind lower tank 41 is partitioned into a plurality of parts in a tube stacking direction X, and throttle plates 410, 411 and 412 are formed as flow rate adjusting members that adjust the flow rate of the refrigerant circulating in the tube stacking direction X. Furthermore, the evaporator 1 is provided with an oil distribution hole 412b formed on the side of a bottom wall 41a of the downwind lower tank 41 to mutually connect lower spaces in the downwind lower tank 41 partitioned by the throttle plate 412 in the tube stacking direction X.

Description

  The present invention relates to an evaporator as one element constituting a refrigeration cycle apparatus.

  As an example of a conventional evaporator, an evaporator described in Patent Document 1 is known. The evaporator described in Patent Document 1 includes a heat exchange core portion in which a tube row group configured by laminating a plurality of tubes extending in the vertical direction in the horizontal direction is arranged in two sets each in the horizontal direction and the air flow direction. I have. Above and below each tube row group, an inlet side tank portion disposed on the leeward side of the air and an outlet side tank portion disposed on the leeward side are respectively provided.

  In the inside of the lower tank part, in order to arbitrarily set the refrigerant flow rate distributed to the tubes arranged in the lateral direction, the first throttle plate to the third throttle plate in which the flow rate adjusting hole for adjusting the refrigerant flow rate is formed. A plate is provided. The lower inlet side tank portion is formed with a collection tank portion for collecting refrigerant and a distribution tank portion for distributing refrigerant. A first throttle plate is provided at the boundary between the collecting tank portion and the distribution tank portion, and a second throttle plate and a third throttle plate are provided at a predetermined interval in the distribution tank portion.

  Similarly, fourth to sixth throttle plates having flow rate adjusting holes that allow the refrigerant flow rate to be adjusted are also provided in the lower outlet side tank. The lower outlet side tank section is formed with a collecting tank portion for collecting refrigerant and a distribution tank portion for distributing refrigerant. A fourth throttle plate is provided at the boundary between the collecting tank portion and the distribution tank portion, and a fifth throttle plate and a sixth throttle plate are provided at predetermined intervals in the distribution tank portion.

  In this conventional evaporator, after flowing into the upper inlet side tank part from the refrigerant inlet, it descends the tube array on the leeward side, reaches the collective tank part of the lower inlet side tank part, and flows to the distribution tank part. After that, it is distributed in a plurality of tubes, flows upward through the tube row group, and flows into the upper inlet side tank portion. Next, the refrigerant moves from the leeward side to the leeward side in the upper inlet side tank part, descends the tube group on the leeward side from the upper outlet side tank part, and the collective tank part of the lower outlet side tank part Then, after flowing to the distribution tank portion, it is distributed into a plurality of tubes, flows upward through the tube array on the windward side, flows into the upper outlet side tank section, and flows out from the refrigerant outlet to the outside.

Japanese Patent No. 3391339

  The process in which the refrigerant circulates in the refrigeration cycle in the tank portion disposed below the evaporator not including the throttle plate as well as the evaporator as in Patent Document 1 having the throttle plate for flow rate adjustment. In some cases, oil contained in the refrigerant may accumulate. When the amount of the oil in the refrigerant staying in the tank increases, the amount of oil sucked into the compressor located downstream of the evaporator decreases. For this reason, the lubrication effect with respect to a compressor is lost and there exists a problem of having a bad influence on the operation | movement of a compressor. In some cases, the compressor may be locked, and the compressor may be damaged.

  In addition, in an evaporator provided with a throttle plate having a flow rate adjusting hole in the lower tank as described in Patent Document 1, oil tends to accumulate at the bottom of the tank located particularly downstream of the throttle plate.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide an evaporator that can reduce the amount of oil contained in the refrigerant in a tank disposed below. That is.

The present invention employs the following technical means to achieve the above object. That is, the invention relating to the evaporator according to claim 1 includes a plurality of flow path row groups (21, 22) formed by laminating a plurality of tubes (20) and including a plurality of passages through which a refrigerant flows. A core part (2) having an upper tank (3) provided so as to include the upper ends of a plurality of tubes (20) constituting the core part (2), and a plurality of parts constituting the core part (2) The lower tank (4) provided so as to include the lower end of the tube (20) therein, and the lower tank (4) are provided inside, and the inner space of the lower tank is partitioned into a plurality in the tube stacking direction (X). And a flow rate adjusting member (410, 411, 412) for adjusting the flow rate of the refrigerant flowing in the tube stacking direction (X),
An oil flow passage (412b) that communicates the lower spaces in the lower tank partitioned in the tube stacking direction (X) by the flow rate adjusting member (412) is set on the bottom wall (41a) side of the lower tank. To do.

  According to the present invention, when the refrigerant flows through the evaporator, the refrigerant flows through the oil flow passage on the bottom wall side of the lower tank, so that the oil staying at the bottom of the lower tank is moved by the fluid pressure. It is possible to improve the staying state by allowing oil to flow into the tube together with the refrigerant. Further, when the refrigerant is not flowing through the evaporator, the oil dispersion effect due to the refrigerant flow pressure cannot be implemented, but the oil staying at the bottom of the lower tank is passed through the oil flow passage to the flow rate adjusting member. It becomes possible to flow into the inner space of the adjacent tank, and the oil can be dispersed elsewhere. The oil dispersed in this way flows into the tube due to the above-described winding effect due to the fluid pressure when the refrigerant flows inside the evaporator, and the retention state can be improved. Therefore, the evaporator which can reduce the quantity which the oil contained in a refrigerant | coolant retains in the tank arrange | positioned below can be provided.

  According to the second aspect of the present invention, in addition to the oil flow passage (412b), the flow rate adjusting member (412) is a throttle that adjusts the flow rate of the refrigerant flowing in the tube stacking direction (X) in the lower tank (4). The opening (412a) is formed, and the oil flow passage (412b) is provided at a position lower than the opening (412a) for throttling.

  According to this invention, in addition to the oil flow passage, the oil remaining in the lower tank is separately supplied to the flow rate adjusting member in which the throttle opening for adjusting the flow rate of the refrigerant flowing in the tube stacking direction in the lower tank is formed. A function of distributing can be provided.

  According to the third aspect of the present invention, a plurality of flow rate adjusting members (410, 411, 412) are arranged in the lower tank (4) at intervals in the tube stacking direction (X), and downstream of the refrigerant flow. The throttle opening (412a) formed in the flow rate adjustment member (412) located at the position has a smaller cross-sectional area than the throttle opening (411a) formed in the flow rate adjustment member (411) located on the upstream side. An oil flow path (412b) is set in at least one of the plurality of flow rate adjusting members (410, 411, 412) formed.

  According to the present invention, the space in the lower tank is partitioned into a plurality of spaces in the tube stacking direction by the plurality of flow rate adjusting members, and the oil in the refrigerant tends to stay in the partitioned internal space. Become. In view of this, the oil flow passage is set in at least one of the plurality of flow rate adjusting members, so that the oil accumulated in the partitioned internal space is positively passed through the oil flow passage to the adjacent internal space. Can escape.

  According to the fourth aspect of the present invention, the oil flow passage (412b) is set in the flow rate adjusting member (412) located on the most downstream side among the plurality of flow rate adjusting members (410, 411, 412). It is characterized by.

  According to the present invention, the space in the lower tank is partitioned into a plurality of spaces in the tube stacking direction by the plurality of flow rate adjusting members, and the oil in the refrigerant tends to stay in the partitioned internal space. Become. This tendency is conspicuous in the most downstream internal space partitioned by the most downstream flow rate adjusting member, and it is considered that the amount of oil staying also increases. Therefore, the oil flow passage is set in the flow rate adjusting member located on the most downstream side, so that oil in a portion where it can easily accumulate can be positively released to the adjacent internal space through the oil flow passage. Therefore, according to claim 4, a great oil dispersion effect in the evaporator can be expected.

  According to the invention described in claim 5, the oil flow passage (412b) is a hole formed by the bottom wall (41a) of the lower tank and a part of the outer edge (412c) of the flow rate adjusting member, To do. According to the present invention, since the bottom wall of the lower tank is used as a part of the inner wall of the oil flow passage, an oil flow passage that passes through a low position inside the lower tank can be formed. Thereby, a small amount of oil staying at the bottom of the lower tank can be moved, and the staying oil dispersibility can be improved.

  According to the invention described in claim 6, a plurality of oil flow passages (64b1, 64b2, 64b3) are formed side by side in the air flow direction (Z) on the bottom wall (41a) side of the lower tank. Features. According to the present invention, a plurality of oil flow passages are formed side by side in the air flow direction, so that the region through which oil can pass is compared with the case where one oil flow passage is formed. It is possible to increase the effect of escaping the oil staying at one place to the other space inside the tank. Further, even when the evaporator is installed in a tilted manner without being erected vertically with respect to the air flow direction, one of the oil flow passages formed in the air flow direction is vertically downward. Since there is a high possibility of being located, the oil staying at the bottom of the lower tank can be surely released through the oil flow passage.

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

It is a perspective view showing appearance about an example of an evaporator to which the present invention is applied. It is a schematic diagram for demonstrating the flow of the refrigerant | coolant in the evaporator of FIG. It is the fragmentary sectional view showing the composition inside the lower tank concerning a 1st embodiment to which the present invention is applied. It is a front view which shows the structure of each aperture_diaphragm | restriction plate shown in FIG. It is a fragmentary sectional view explaining the oil retention state inside a lower tank in the evaporator of patent documents 1. FIG. 4 is a partial cross-sectional view illustrating a refrigerant flow in the vicinity of the most downstream throttle plate in the lower tank shown in FIG. 3. FIG. 4 is a partial cross-sectional view illustrating the flow of oil in the most downstream portion in the lower tank shown in FIG. 3. It is a front view which shows the 1st other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 2nd other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 3rd other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 4th other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 5th other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 6th other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is a front view which shows the 7th other form which is a modification of the aperture_diaphragm | restriction plate shown in FIG. It is the fragmentary sectional view which showed the structure inside the lower tank which concerns on 2nd Embodiment to which this invention is applied.

  A plurality of modes for carrying out the present invention will be described below with reference to the drawings. In each embodiment, parts corresponding to the matters described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. In the case where only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those described previously. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination does not hinder the combination.

(First embodiment)
1st Embodiment which is one Embodiment of this invention is described with reference to FIGS. FIG. 1 is a perspective view showing an appearance of an example of an evaporator 1 to which the present invention is applied. FIG. 2 is a schematic diagram for explaining the flow of the refrigerant in the evaporator 1 of FIG.

  The evaporator 1 is a component disposed in a refrigeration cycle used in, for example, a vehicle air conditioner. The evaporator 1 is a heat exchanger in which a refrigerant compressed to a high pressure by a compressor in a refrigeration cycle is radiated and cooled by a radiator and depressurized to a low temperature and a low pressure by a decompressor, and then evaporates. It serves to cool the air that passes through it.

  As shown in FIGS. 1 and 2, the evaporator 1 is mainly composed of a core portion 2, an upper tank 3, a lower tank 4, and the like. The core portion 2 is configured by alternately laminating a plurality of tubes 20 and a plurality of outer fins 23, and disposing side plates 24 further outside the outer fins 23 at both outermost end portions in the laminating direction. The outer fin 23 is a heat exchange fin. 1 and 2, the X direction is a tube stacking direction (or a lateral direction) in which a plurality of tubes 20 are arranged, the Z direction is an air flow direction in which air to be cooled flows, and the Y direction is a tube. The direction in which 20 extends (or the longitudinal direction of the tube, the direction of refrigerant flow in the tube) is the vertically upward direction.

  The core portion 2 of the evaporator 1 has a plurality of rows in which the tubes 20 extending in the vertical direction are arranged in the horizontal direction, one row on each of the upstream side and the downstream side of the air flow that is the external fluid exchanged with the refrigerant, It is configured to be arranged in at least two rows in the air flow direction. The tube 20 is a tubular member formed such that a transverse cross section perpendicular to the longitudinal direction (or the refrigerant flow direction in the tube) has a flat shape by bending a thin aluminum strip-shaped plate. For example, an inner fin is joined in the tube 20.

  The core portion 2 includes a single leeward flow channel group 21 composed of a plurality of passages formed by arranging a plurality of tubes 20 extending in the vertical direction in the horizontal direction and arranged on the downstream side of the air flow, and the vertical direction. A plurality of tubes 20 extending in the horizontal direction are arranged side by side and arranged on the upstream side of the air flow. The plurality of leeward side flow channel arrays 21 and the plurality of the windward flow channel groups 22 are overlapped and integrated in the air flow direction Z to constitute the core portion 2. The number of each of the leeward side flow path row group 21 and the windward side flow path row group 22 is determined by the refrigerant flow pattern in the core portion.

  The refrigerant flowing through each leeward flow channel group 21 flows in the same direction in the plurality of tubes 20 constituting the flow channel group, and the plurality of leeward flow channel groups 21 include the leeward upper tank 31 and the leeward side. It communicates with the inside of the lower tank 41. The refrigerant flowing through each windward flow channel group 22 flows in the same direction in a plurality of tubes constituting the flow channel group, and the plurality of windward flow channel groups 22 include the windward upper tank 32 and the windward lower tank. The communication is made through the inside of 42.

  The outer fins 23 are corrugated fins obtained by processing a thin aluminum strip material into a corrugated shape. For example, a louver is formed on the surface to increase heat exchange efficiency. The outer fin 23 is brazed to the outer surface of the tube 20.

  The side plate 24 is a reinforcing member in the core portion 2 and is formed by pressing an aluminum flat plate material. The longitudinal direction end portion side of the side plate 24 is formed in a flat plate shape, and most other parts are formed to have a U-shaped cross section that opens to the outside in the stacking direction of the tube 20 and the outer fin 23. It is brazed to the outer fin 23.

  The leeward side upper tank 31 is a tank to which the upper ends of the plurality of leeward side flow path row groups 21 are connected, and the leeward side lower tank 41 is a tank to which the lower ends of the plurality of leeward side flow passage row groups 21 are connected. is there. The leeward side upper tank 31 is a chamber that distributes the refrigerant flowing in from the outside into a plurality of tubes constituting the leeward side flow channel array group 21, and in the plurality of tubes constituting the leeward side flow path array group 21. It is a chamber in which the refrigerant that has flowed through is collected. The leeward side lower tank 41 is a chamber in which the refrigerant flowing through the plurality of tubes constituting the leeward side flow channel group 21 is collected, and into the plurality of tubes constituting the leeward side flow channel group 21. It is a chamber for distributing refrigerant.

  A block-like connector 5 is brazed and joined to the left side end portion (the end portion on the opposite side in the X direction) of the leeward side upper tank 31 in order to introduce the refrigerant into the core portion 2. Is provided with an inlet 51 provided to communicate with the inside of the leeward upper tank 31.

  The windward upper tank 32 is a tank connected to the upper ends of the plurality of windward flow path row groups 22, and the windward lower tank 42 is a tank to which the lower ends of the plurality of windward flow passage row groups 22 are connected. is there. The windward upper tank 32 is a chamber that distributes the refrigerant flowing in from the leeward upper tank 31 into a plurality of tubes constituting the windward flow path group 22 and also constitutes the windward flow path group 22. This is a chamber in which the refrigerant flowing through the plurality of tubes is collected. The windward lower tank 42 is a chamber in which the refrigerant flowing through the plurality of tubes constituting the windward flow path row group 22 is collected, and into the plurality of tubes constituting the windward flow path row group 22. It is a chamber for distributing refrigerant.

  The connector 5 is brazed and joined to the left end (end opposite to the X direction) of the upwind upper tank 32 in the length direction, and the connector 5 supplies the refrigerant from the inside of the core portion 2 to the refrigeration cycle apparatus. An outflow port 52 is provided so as to communicate with the inside of the upwind upper tank 32 so as to flow out to the external parts. In this way, the inflow port 51 and the outflow port 52 are provided on the same side (one side opposite to the X direction in this embodiment) of one end portion in the length direction of the upper tank 3.

  The upper tank 3 is composed of an anti-tube side tank header and a tube side plate header that are divided into two in the tube longitudinal direction (vertically upward direction Y), and is provided with a cap, and a leeward upper tank 31 and an leeward upper tank. 32. Each of the tank header and the plate header has a cross-sectional shape in which two semicircular shapes or two semirectangular shapes are connected, and is formed by pressing an aluminum flat plate. Both headers are fitted and brazed together to form a cylindrical body in which two internal spaces are arranged in the air flow direction Z to be blown. Caps formed by pressing a flat plate made of aluminum by brazing are brazed and joined to the respective openings at the longitudinal ends of the leeward upper tank 31 and the leeward upper tank 32, thereby closing the openings. .

  Furthermore, a plurality of separators that divide the two internal spaces in the X direction are brazed and joined to the upper tank 3. The inside of the windward upper tank 32 is divided into two spaces in the length direction by a separator 32a. The inside of the leeward upper tank 31 is divided into two spaces in the length direction by a separator 31a (leeward upper partition wall).

  The separator 31a has a leeward side flow channel group 21b as an ascending flow channel sequence group in which the refrigerant flow is an upward flow in the leeward core portion and a leeward flow channel as a down flow channel sequence group in which the refrigerant flow is downward. It is a leeward side partition wall that is provided in the leeward side upper tank 31 so as to be adjacent to the row group 21a and reverses the upward flow and the downward flow. The separator 32a includes a windward flow path group 22b as an ascending flow path array group in which the refrigerant flow is an upward flow in the core on the windward side, and a windward flow path as a downward flow path array group in which the refrigerant flow is a downward flow. The windward partition wall is provided in the windward upper tank 32 so as to be adjacent to the row group 22a and reverses the upward flow and the downward flow.

  In the area on the right side (X direction) of the separator 31 a inside the leeward upper tank 31, the inner space on the right half of the leeward upper tank 31 in the length direction and the inner space on the right half of the leeward upper tank 32 in the length direction. Are communicated with each other through a plurality of upper communication holes 300.

  The upper side communication hole 300 is formed in a wall that divides the inside of the tank provided on the opposite side to the end portion on the side where the inflow port 51 and the outflow port 52 are located into the leeward side and the leeward side. Each upper communication hole 300 includes an inside of the leeward side upper tank 31 connected to the leeward side flow channel array group 21b located at a position farthest from the inflow port 51 and an upwind flow path located at a position farthest from the outflow port 52. It becomes a communication means which connects the inside of the windward upper tank 32 connected to the row group 22a.

  FIG. 3 is a partial cross-sectional view showing an internal configuration of the lower tank 4 according to the first embodiment. FIG. 4 is a front view of the configuration of each diaphragm plate shown in FIG. 3 when viewed in the X direction. The arrows in FIG. 3 indicate the flow of the refrigerant in the lower tank 4.

  As shown in FIG. 3, the lower tank 4 includes a leeward lower tank 41 and an leeward lower tank 42 and has a form similar to that of the upper tank 3, and is a cylindrical body constituted by a tank header and a plate header. A cap 43 is provided at each opening at both ends in the longitudinal direction.

  As shown in FIG. 3 and FIG. 4, an aperture for throttling is provided at the center in a portion located in the boundary between the leeward side channel group 21 a and the leeward side channel group 21 b in the leeward lower tank 41. A diaphragm plate 410 having a through hole 410a as a portion is provided. A throttle plate 411 is further provided in the leeward lower tank 41 at a predetermined interval from the throttle plate 410 in the X direction. The aperture plate 411 has a through hole 411a having a smaller opening area at the center than the through hole 410a of the upstream aperture plate 410. Inside the leeward side lower tank 41, a throttle plate 412 is further provided at a predetermined interval from the throttle plate 411 in the X direction. That is, inside the windward lower tank 41, the throttle plates 410, 411, 412 are arranged in this order toward the refrigerant flow downstream (X direction). Each diaphragm plate is a member made of aluminum like a tank or the like.

  A through-hole 412a having a smaller opening area than the through-hole 411a of the upstream-side throttle plate 411 is formed in the center of the throttle plate 412 located most downstream in the refrigerant flow among the plurality of throttle plates. Further, the throttle plate 412 is formed with a concave edge 412c having a shape in which an outer peripheral edge is recessed toward the center side in order to form an oil circulation hole 412b on the bottom wall 41a side of the lower tank. Therefore, the oil circulation hole 412b is a hole formed by the bottom wall 41a of the lower tank and the concave edge portion 412c which is a part of the outer edge of the throttle plate 412. That is, the oil flow passage in this case uses the bottom wall 41a of the lower tank as a part of the passage wall. Since the oil circulation hole 412b is formed below the through hole 412a, the tank inner space on one side and the tank on the other side in the tube stacking direction X with respect to the throttle plate 412 on the bottom wall 41a side of the lower tank. An oil flow passage that communicates with the inner space is formed.

  Similar to the throttle plates 410 to 412 in the leeward lower tank 41, the windward lower tank 42 has a portion located at the boundary between the windward flow channel group 22a and the windward flow channel group 22b. A diaphragm plate 420 having a through hole 420a as a diaphragm opening is formed at the center. Inside the windward lower tank 42, a throttle plate 421 is provided at a predetermined interval in the X direction from the throttle plate 420, and further, a throttle plate 422 is provided at a predetermined interval from the throttle plate 421 in the X direction. That is, inside the windward lower tank 42, the throttle plates 420, 421, and 422 are arranged in this order toward the refrigerant flow downstream (X direction).

  A through hole 422a having a smaller opening area than the through hole 421a of the upstream side throttle plate 421 is formed in the center of the throttle plate 422 located at the most downstream side of the refrigerant flow among the plurality of throttle plates. Further, the throttle plate 422 is formed with a concave edge 422c whose outer peripheral edge is recessed toward the center in order to form the oil circulation hole 422b on the bottom wall 42a side of the lower tank. Therefore, the oil circulation hole 422b is a hole formed by the bottom wall 42a of the lower tank and the concave edge 422c that is a part of the outer edge of the throttle plate 422. That is, the oil flow passage in this case uses the bottom wall 42a of the lower tank as a part of the passage wall. Since the oil circulation hole 422b is formed at a position lower than the through hole 422a, on the bottom wall 42a side of the lower tank, the tank inner space on one side of the tube stacking direction X with respect to the throttle plate 422 and the other side An oil flow passage that communicates with the space in the tank is formed.

  Each of the throttle plates 410 to 412 and 420 to 422 has a through hole having an opening area smaller than the flow passage cross-sectional area inside each of the lower tanks 41 and 42, thereby giving a flow resistance to the flow of the refrigerant. It functions as a flow rate adjusting member that adjusts the flow rate of the refrigerant passing through the plate.

  The total of the opening area of the through hole 412a and the opening area of the oil circulation hole 412b is set smaller than the opening area of the upstream through hole 411a and the opening area of the through hole 410a. The total of the opening area of the through hole 422a and the opening area of the oil circulation hole 422b is set smaller than the opening area of the upstream through hole 421a and the opening area of the through hole 420a.

  In FIG. 2, the constituent elements such as the separators 31a and 32a, the throttle plates 410 to 412 and 420 to 422, and the upper communication hole 300 arranged in each tank are indicated by solid lines for easy recognition. ing.

  Here, with reference to FIG. 5, the mechanism in which the oil in a refrigerant | coolant retains in the inside of the lower tank of the conventional evaporator is demonstrated. FIG. 5 is a partial cross-sectional view for explaining an oil retention state inside the lower tank in the evaporator of Patent Document 1 described above.

  As shown in FIG. 5, the conventional evaporator includes a plurality of throttle plates with through holes formed therein for reducing the refrigerant flow rate in the lower tank. The throttling through-holes become smaller toward the downstream side of the refrigerant flow, so that a large amount of refrigerant flows into the tank internal space partitioned on the most downstream side of the refrigerant flow, This makes it possible to equalize the refrigerant distribution. Therefore, by equalizing the refrigerant distribution to each tank internal space, the refrigerant can be made to flow uniformly into the plurality of tubes constituting the core portion without unevenness, and excellent refrigerant distribution is improved.

  However, contrary to this improvement in refrigerant distribution, there is a problem that oil contained in the refrigerant stays and settles in the tank internal space defined by the throttle plate. This stagnation of oil can occur in all tank internal spaces partitioned by the throttle plate, but is particularly noticeable in the tank internal space located downstream (tube stacking direction X) from the throttle plate located on the most downstream side. is there. The oil once accumulated in this way tends to be blocked by the throttle plate because the opening area of the through hole formed in the most downstream throttle plate is small, and it is difficult to escape to the adjacent tank internal space. It stays in place, and the amount of residence tends to increase. When the amount of oil remaining in the evaporator increases as described above, the amount of oil that can be sucked by the compressor decreases, so that the effect of lubricating the compressor decreases and the compressor is liable to be adversely affected.

  Therefore, according to the evaporator 1 of the present embodiment, in the throttle plates 410 to 412 and 420 to 422 in the windward lower tank 41 or the windward lower tank 42, particularly in the throttle plates 412 and 422 located on the most downstream side, The flow holes 412b and 422b are formed on the bottom walls 41a and 42a side of the lower tank. With this configuration, the lower spaces inside the lower tank partitioned by the throttle plates 412 and 422 in the tube stacking direction X communicate with each other through the oil circulation holes 412b and 422b. The flow of the refrigerant and oil in this case will be described with reference to FIGS.

  FIG. 6 is a partial cross-sectional view for explaining the refrigerant flow in the vicinity of the most downstream throttle plate 412 in the leeward lower tank 41 shown in FIG. 3, and shows, for example, a state during operation of the air conditioner. FIG. 7 is a partial cross-sectional view illustrating the refrigerant flow in the vicinity of the most downstream throttle plate 412 in the leeward lower tank 41 shown in FIG. 3, and shows, for example, a state when the air conditioner is stopped.

  As shown in FIG. 6, in the case where oil stays in the internal space of the lower tank (hereinafter referred to as the most downstream tank internal space) located downstream (in the tube stacking direction X) from the throttle plate 412, the air conditioner Due to the compression of the compressor accompanying the operation, the refrigerant passes through the through hole 412a as shown by the arrow in the figure, and further passes through the oil circulation hole 412b but flows into the most downstream tank internal space. At this time, the oil accumulated in the bottom of the most downstream tank internal space is moved and diffused by the refrigerant flowing through the oil circulation hole 412b and flowing into the bottom side, so that the staying state is improved. For example, the oil is wound up by the refrigerant flow passing through the oil circulation hole 412b and becomes mist-like and easily flows. The diffused oil flows into the tube 20 together with the refrigerant by the flow of the refrigerant, and flows in the refrigeration cycle.

  Further, as shown in FIG. 7, when the air conditioner is stopped, the oil accumulated at the bottom of the most downstream tank internal space does not move depending on the refrigerant flow, but passes through the oil circulation hole 412b and is more than the throttle plate 412. It flows in the adjacent tank internal space located upstream. As a result, the amount of oil remaining in the most downstream tank internal space is dispersed in other tank internal spaces. Since the staying state of the dispersed oil is further improved by the oil diffusion action by the refrigerant flow described above with reference to FIG. 6, the oil flows in the refrigeration cycle and lubricates the components of the refrigeration cycle. Can be demonstrated.

  Next, the refrigerant flow in the entire evaporator 1 having the above configuration will be described in order. After the refrigerant flowing into the evaporator 1 from the external component parts of the refrigeration cycle apparatus flows into the leeward upper tank 31 that is the space on the left side in the lateral direction (opposite to the X direction) from the inlet 51, the separator 31a. The leeward side flow channel group 21a is lowered, and the oil retention state is improved as described above inside the leeward lower tank 41 which is a space on the right side in the lateral direction (X direction) from the throttle plate 410. After being distributed, the flow is reversed, the leeward side flow channel group 21b is raised, and flows into the leeward side upper tank 31 which is a space on the right side in the horizontal direction (X direction) with respect to the separator 31a.

  The refrigerant that has flowed into the internal space in the X direction of the leeward upper tank 31 flows toward the windward side through the plurality of upper side communication holes 300, reaches the inside of the windward upper tank 32, and reaches the windward side flow path row. The group 22a is lowered and enters the windward lower tank. Furthermore, after the refrigerant has been distributed in flow rate while improving the oil retention state as described above, inside the upwind lower tank 42, which is the space on the left side in the lateral direction (opposite side in the X direction) from the throttle plate 420, Inverted, ascends the windward flow path group 22b, and passes through the upper outlet 52 from the inside of the windward upper tank 32, which is the space on the left side in the lateral direction (opposite to the X direction) from the separator 32a. To leak.

  Below, the effect which the evaporator 1 of this embodiment brings is described. In the inside of the leeward lower tank 41 that is one of the lower tanks 4 in the evaporator 1, the internal space of the leeward lower tank 41 is divided into a plurality of tubes in the tube stacking direction X, and the refrigerant flows in the tube stacking direction X. The throttle plates 410, 411, and 412 are provided as flow rate adjusting members for adjusting the flow rate of the first and second flow rates. Further, the evaporator 1 has an oil flow passage (oil flow hole 412b) that communicates the lower spaces in the leeward lower tank 41 partitioned by the throttle plate 412 in the tube stacking direction X on the bottom wall 41a side of the lower tank. is doing.

  According to this configuration, when the refrigerant flows inside the evaporator 1, for example, during the operation of the air conditioner, the refrigerant flows through the oil circulation hole 412 b on the bottom wall 41 a side of the lower tank. The oil staying in the tank can be moved or rolled up by the fluid pressure. This action allows the oil that has stayed to flow into the tube 20 that extends upward together with the refrigerant, thereby improving the oil retention state.

  Also, when the refrigerant does not flow inside the evaporator 1, for example, when the air conditioner is stopped, the oil dispersion action due to the refrigerant fluid pressure cannot be obtained, but the oil staying at the bottom of the lower tank is removed. It is possible to flow through the oil circulation hole 412b to the adjacent tank internal space partitioned by the throttle plate 412 and to disperse the oil to other locations, thereby reducing the amount of residence at one location. The oil dispersed in this manner is used when the refrigerant flows in the evaporator 1 such as when the air conditioner is operated next time. Inhaled together with the refrigerant, the staying state can be improved.

  In addition to the oil circulation hole 412b, the evaporator 1 of the present embodiment separately includes a throttle plate 412 provided with a through hole 412a as a throttle opening for adjusting the flow rate of the refrigerant flowing in the tube stacking direction in the lower tank. Have. The evaporator 1 having such a throttle plate can provide a function of dispersing oil accumulated in the leeward lower tank 41.

  In addition, the throttle plates 410 to 412 or 420 to 422 as flow rate adjusting members are arranged side by side in the leeward lower tank 41 or the leeward lower tank 42 with a predetermined interval in the tube stacking direction X. An oil flow passage is set in at least one of the plurality of throttle plates 410 to 412 or 420 to 422.

  According to this configuration, the space in the leeward lower tank 41 or the windward lower tank 42 is partitioned into a plurality of spaces in the tube stacking direction X by the plurality of throttle plates, and the inside of the partitioned tanks Oil in the refrigerant tends to stay in the space. Therefore, by setting an oil flow passage in at least one of the plurality of throttle plates, oil accumulated in the partitioned tank internal space is actively released to the adjacent internal space through the oil flow passage. It is possible to eliminate the stagnation of oil at a specific location and to disperse the oil in the refrigeration cycle.

  Further, the through hole 412a or 422a of the aperture for opening formed in the throttle plate 412 or 422 located on the downstream side of the refrigerant flow is cut off from the through hole formed in the throttle plate located on the upstream side of this. The area is formed small. Of the plurality of throttle plates 410 to 412 or 420 to 422, an oil circulation hole 412b or 422b is set in the throttle plate 412 or 422 located on the most downstream side.

  According to this configuration, the space in the lower tank is partitioned into a plurality of spaces in the tube stacking direction X by the plurality of throttle plates, and the oil in the refrigerant stays in each partitioned internal space. It becomes easy to do. This tendency is conspicuous in the most downstream internal space defined by the most downstream throttle plate 412 or 422, and the oil retention amount is also increased. Therefore, the oil circulation holes 412b or 422b are set in the throttle plate 412 or 422 located on the most downstream side, so that the oil in a portion that is likely to accumulate can be released toward the adjacent internal space. For this reason, the evaporator 1 which has an oil escape passage in the site | part which has the most oil dispersion effect can be provided.

  The oil circulation hole 412b is a hole formed by a bottom wall 41a of the lower tank and a concave edge 412c which is a part of the outer edge of the throttle plate 412, so that the bottom wall 41a of the lower tank is passed through the oil flow passage. It can be used as a part of the inner wall. For this reason, since the oil flow path which passes through the low position inside the lower tank can be formed, it is possible to move a small amount of oil staying at the bottom of the lower tank. Accordingly, it is possible to improve the ability to disperse the oil staying at the bottom of the lower tank.

(Other forms of aperture plate)
Hereinafter, other embodiments included in the scope of the present invention will be described with reference to FIGS. 8 to 14 for the diaphragm plate described in the first embodiment. In the drawings showing the other embodiments, the constituent elements denoted by the same reference numerals as those described in the first embodiment are the same elements, and the operational effects thereof are also the same. Further, the throttle plate shown in each figure can be installed not only in the leeward lower tank 41 but also in the leeward lower tank 42.

  FIG. 8 is a front view showing a first other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 8, the throttle plate 60 according to the first other form also serves as a throttle opening for adjusting the refrigerant flow rate by the oil circulation hole 60 b set on the bottom wall 41 a side of the lower tank. It has a configuration. That is, the throttle plate 60 does not have a separate throttle opening in the center, and the refrigerant flows through the lower oil circulation hole 60b to flow inside the leeward lower tank 41, so that the remaining oil Can pass through the internal space defined by the leeward lower tank 41 through the lower oil circulation hole 60b.

  Further, the throttle plate 60 shown in FIG. 8 is formed with a concave edge portion 60c having a shape in which the outer peripheral edge is recessed toward the center side in order to form the oil circulation hole 60b on the bottom wall 41a side of the lower tank. Therefore, the oil circulation hole 60 b is a hole formed by the bottom wall 41 a of the lower tank and the concave edge portion 60 c that is a part of the outer edge of the throttle plate 60. That is, the oil flow passage in this case uses the bottom wall 41a of the lower tank as a part of the passage wall.

  Next, FIG. 9 is a front view showing a second other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 9, the throttle plate 61 as the second other form has a shape in which a part of the bottom wall 41a1 of the leeward lower tank 41A protrudes downward. Due to the shape of the bottom wall 41a1 of the lower tank, the oil circulation hole 61b is a hole formed by the bottom wall 41a1 of the lower tank and the outer peripheral edge 61c of the throttle plate 60. In other words, the oil flow passage in this case uses the bottom wall 41a1 of the lower tank as a part of the passage wall. Further, the aperture plate 60 is formed with a through hole 61a at the center as an aperture for aperture. With the configuration shown in FIG. 9, the refrigerant mainly passes through the through hole 61a and flows in the leeward lower tank 41A, and the oil in the staying state passes through the oil circulation hole 60b on the bottom wall 41a1 side of the lower tank. It is possible to go back and forth through the internal space defined by the leeward lower tank 41A.

  Next, FIG. 10 is a front view showing a third other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 10, the throttle plate 62 according to the third other embodiment has a throttle opening for adjusting the refrigerant flow rate by an oil circulation hole 62 b formed as a through hole on the bottom wall 41 a side of the lower tank. It is equipped with the structure which serves as both. That is, the throttle plate 62 is not separately formed with a throttle opening at the center, and the refrigerant flows through the lower oil circulation hole 62b to flow inside the leeward side lower tank 41, so that the remaining oil Can pass through the internal space defined by the leeward lower tank 41 through the lower oil circulation hole 62b.

  Next, FIG. 11 is a front view showing a fourth other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 11, the throttle plate 63 according to the fourth other form includes a through hole 63a formed in the center, an oil circulation hole 63b formed as a through hole on the bottom wall 41a side of the lower tank, It has. With this configuration, the refrigerant flows through the lower oil circulation hole 63b and flows in the leeward lower tank 41, and the staying oil passes through the lower oil circulation hole 63b and is partitioned into the leeward lower tank 41. It is possible to go back and forth through the internal space.

  Next, FIG. 12 is a front view showing a fifth other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 12, a plurality of oil flow passages arranged in the air flow direction Z on the bottom wall 41a side of the lower tank are set in the throttle plate 64 which is the fifth other form. Three oil circulation holes 64b1, 64b2, 64b3 as the oil flow passages are formed side by side in the air flow direction Z. The three oil flow passages also serve as throttle openings for adjusting the refrigerant flow rate. That is, the throttle plate 64 does not have a separate throttle opening at the center, and the refrigerant flows through the lower oil circulation holes 64b1, 64b2, 64b3 and flows inside the leeward lower tank 41, The staying oil can pass through the lower oil circulation holes 64 b 1, 64 b 2, 64 b 3 and back and forth in the internal space defined by the leeward lower tank 41.

  In addition, the throttle plate 64 shown in FIG. 12 has concave edges 64c1, 64c2 whose outer peripheral edges are recessed toward the center in order to form oil circulation holes 64b1, 64b2, 64b3 on the bottom wall 41a side of the lower tank. , 64c3 are formed. Accordingly, each of the oil circulation holes 64b1, 64b2, and 64b3 is a hole formed by the bottom wall 41a of the lower tank and the concave edge portions 64c1, 64c2, and 64c3 that are part of the outer edge of the throttle plate 64. That is, the oil flow passage in this case uses the bottom wall 41a of the lower tank as a part of the passage wall.

  According to the configuration of the throttle plate 64, a plurality of oil circulation holes 64b1, 64b2, 64b3 are formed side by side in the air flow direction Z. Can be broadly set in the air flow direction Z in the tube stacking direction X. Therefore, the oil staying in the leeward lower tank 41 can be released to another space, and the effect of dispersing the oil can be improved. Further, even when the evaporator 1 is installed tilted without standing vertically to the air flow direction Z, any of the plurality of oil circulation holes 64b1, 64b2, 64b3 formed in the air flow direction Z. Since it can be positioned vertically downward or approaching vertically downward, the oil staying at the bottom of the leeward lower tank 41 can be surely released to another space.

  Next, FIG. 13 is a front view showing a sixth other form which is a modification of the diaphragm plate shown in FIG. As shown in FIG. 13, the throttle plate 65 according to the sixth other form includes a through hole 65a formed in the center and three oil circulation holes formed as a through hole on the bottom wall 41a side of the lower tank. 65b1, 65b2, 65b3. The three oil circulation holes 65b1, 65b2, 65b3 are parts of the bottom wall 41a of the lower tank and a part of the outer edge of the throttle plate 65, similarly to the oil circulation holes 64b1, 64b2, 64b3 in the fifth other embodiment. It is a hole formed by the concave edge portions 65c1, 65c2, 65c3. That is, the oil flow passage in this case uses the bottom wall 41a of the lower tank as a part of the passage wall.

  With this configuration, the refrigerant mainly passes through the through-hole 65a and flows through the inside of the leeward lower tank 41, and the staying oil passes through the lower oil circulation holes 65b1, 65b2, and 65b3, and reaches the leeward lower tank 41. It is possible to go back and forth inside the partitioned space.

  Next, FIGS. 14A to 14C are front views showing a seventh other form which is a modification of the diaphragm plate shown in FIG. As shown in FIGS. 14A to 14C, a predetermined number of through holes are formed in each of the diaphragm plates 660 to 662, which is the seventh other form. The through hole of each throttle plate functions as a throttle opening in each plate, and the total opening area of each through hole exhibits a function of adjusting the refrigerant flow rate in each throttle plate. That is, the total opening area of the throttle plate is smaller toward the plate located downstream (X direction) of the refrigerant flow.

  As shown in FIG. 14 (a), in the portion located at the boundary between the leeward side flow channel group 21a and the leeward side flow channel group 21b in the leeward lower tank 41, an aperture for throttling from the upper part to the center part. A diaphragm plate 660 in which 16 through holes 660a are formed is provided. Further, a throttle plate 661 is provided inside the leeward side lower tank 41 at a predetermined interval in the X direction from the throttle plate 660. As shown in FIG. 14B, the throttling plate 661 has thirteen through holes 661a formed as throttling openings at the center. The thirteen through holes 661a of the diaphragm plate 661 are smaller in number than the sixteen through holes 660a of the upstream diaphragm plate 660, so that the total opening area of the plate is set smaller for the diaphragm plate 661. Yes.

  Further, a throttle plate 662 is provided in the leeward lower tank 41 at a predetermined interval from the throttle plate 661 in the X direction. As shown in FIG. 14C, the throttle plate 662 is formed with five through holes 661a as a throttle opening at the center and three oil circulation holes 662b1, 662b2, as oil drain holes at the lower part. 662b3 is formed. The five through holes 661a and the three oil circulation holes in the throttle plate 662 are smaller in number than the thirteen through holes 660a in the upstream throttle plate 661, and the total opening area in the plate is equal to that of the throttle plate 662. Is set smaller.

  The three oil circulation holes 662b1, 662b2, and 662b3 that also function as the apertures for the aperture are formed at positions below the five through-holes 661a, so that the aperture plate 661 is formed on the bottom wall 41a side of the lower tank. On the other hand, an oil flow passage that communicates the tank inner space on one side and the tank inner space on the other side in the tube stacking direction X is formed. Also, three oil circulation holes 662b1, 662b2, 662b3 as oil flow passages are formed side by side in the air flow direction Z, as in the fifth other embodiment. Further, the opening sizes of the through holes 661a and the oil circulation holes 662b1, 662b2, and 662b3 may not be equal. For example, the size of each opening becomes smaller as the throttle plate is located downstream of the refrigerant flow. It may be set.

  The throttle plates 660 to 662 of the seventh other form are flow rate adjusting members provided with a plurality of small openings such as punching holes, for example, as throttle openings and oil flow passages in the throttle plate. It is not limited to such a form. For example, the flow rate adjusting member may have a mesh structure such as a mesh material. Even in this case, the throttle opening and the oil flow passage according to the present invention are formed in the flow rate adjusting member having a mesh structure.

(Second Embodiment)
2nd Embodiment demonstrates the other form with respect to 1st Embodiment about the aperture plate provided so that the inside of the lower tank 4 may be divided into a some space. FIG. 15 is a partial cross-sectional view showing a configuration inside the lower tank 4 according to the second embodiment. In FIG. 15, the constituent elements having the same reference numerals as those in FIG. 3 are the same elements, and the operational effects thereof are also the same.

  In the second embodiment, an oil circulation hole is formed in the most downstream throttle plate 413 provided in the lower tank 4 (the leeward lower tank 41, the leeward lower tank 42) as compared with the first embodiment. There are no differences. The oil circulation hole 412b is formed in the throttle plate 412A located adjacent to the upstream side of the most downstream throttle plate 413. Except for these differences, the evaporator according to the second embodiment and the evaporator according to the first embodiment are the same and exhibit the same effects. Hereinafter, the internal configuration of the leeward lower tank 41 will be described with reference to FIG.

  As shown in FIG. 15, a portion located in the boundary between the leeward side flow channel group 21 a and the leeward side flow channel group 21 b in the leeward lower tank 41 is provided as a throttle opening in the center. A diaphragm plate 410 having a through hole 410a is provided. Inside the leeward side lower tank 41, a throttle plate 411, a throttle plate 412A, and a throttle plate 413 are sequentially provided in the X direction from the throttle plate 410, that is, at a predetermined interval toward the downstream side of the refrigerant flow. That is, in the windward lower tank 41, four throttle plates are arranged in the order of the throttle plates 410, 411, 412A, and 413 toward the downstream side of the refrigerant flow. The aperture plate 413 has a through hole 413a as an aperture for aperture in the center. The opening area of the through hole 413a is set smaller than the sum of the opening area of the upstream through hole 412a and the opening area of the oil circulation hole 412b. Each diaphragm plate is a member made of aluminum like a tank or the like.

  Among the plurality of throttle plates, the tank internal space (hereinafter also referred to as the most downstream tank internal space) formed between the throttle plate 413 located most downstream in the refrigerant flow and the cap 43 is the adjacent throttle plate 412A. It is smaller than the tank internal space formed between the nozzle plate 413 and the throttle plate 413, and is the smallest among the other tank internal spaces partitioned so as to be aligned in the tube stacking direction X. In the most downstream tank internal space, for example, the lower end of one tube 20 is included, and this number is the tube 20 included in the tank internal space formed between the adjacent throttle plate 412A and the throttle plate 413. Less than the number of (3).

  That is, since the flow rate of the refrigerant flowing into the most downstream tank internal space is small, the amount of oil staying in the lower part of the most downstream tank internal space is smaller than the staying amount in other tank internal spaces. For this reason, an oil circulation hole for extracting oil is not formed in the throttle plate 413 positioned most downstream in the refrigerant flow. Instead, the oil circulation hole 412b is set in the adjacent upstream throttle plate 412A. The oil circulation hole 412b removes the oil remaining in the lower part of the tank internal space formed between the throttle plate 412A and the throttle plate 413, which is located on the most downstream side except the most downstream tank internal space. This function serves to eliminate the oil from staying at a specific location as a path to escape or by a stirring action caused by the flow of the refrigerant.

(Other embodiments)
The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

  Moreover, although the said embodiment demonstrated the form that the flow-path row | line group which comprises a core part and is located in a line with the air flow direction Z is two flow-path row | line groups, it is not limited to this Alternatively, the flow path row group may be composed of three or more rows.

  Moreover, the core part in the said embodiment may be a core part provided with the core part which does not provide an outer fin between tubes, or the projection part cut and raised from the member which forms a tube between tubes. When the core part is a finless type that does not include fins between tubes, or the core part is a type that includes fins that are joined to only one tube between adjacent tubes. Since the drainage performance of the condensed water condensed on the outer surface of the core part is very good, accurate temperature detection of the core part is easy, and good responsiveness is obtained and useful.

  Moreover, although the example which used the evaporator for the refrigerating cycle of the vehicle air conditioner was demonstrated in the said embodiment, this invention is applied also to the evaporator used for refrigerating cycles other than a vehicle air conditioner. It goes without saying that it can be done.

  Further, although the thickness dimension of the windward flow path group 22 and the thickness dimension of the leeward flow path group 21 in the air flow direction are substantially equal to each other, they may be different dimensions. For example, when the thickness dimension of the leeward side flow channel group 21 is made larger than that of the windward side channel row group 22, the cross-sectional area of the leeward side flow channel where the dryness becomes larger becomes larger, so heat exchange The pressure loss of the refrigerant as a whole can be reduced.

2 ... Core part 3 ... Upper tank 4 ... Lower tank 20 ... Tube 21 ... Downward flow path row group (flow path row group)
22 ... Upstream channel group (channel group)
31 ... Downward upper tank (upper tank)
32 ... Upward tank (upper tank)
41 ... leeward lower tank (lower tank)
41a ... Bottom wall of lower tank 42 ... Upwind lower tank (lower tank)
42a ... Bottom wall of lower tank 64b1, 64b2, 64b3 ... Oil circulation hole (oil flow passage)
410, 411, 412, 412 A, 413... Throttle plate (flow rate adjusting member)
412a ... Through hole (diaphragm opening)
412b, 422b ... Oil circulation hole (oil flow passage)
412c ... concave edge (a part of the outer edge of the flow rate adjusting member)
420, 421, 422 ... Restriction plate (flow rate adjusting member)
X ... Tube stacking direction Y ... Vertical upward direction Z ... Air flow direction

Claims (6)

A core portion (2) having a plurality of flow path row groups (21, 22) formed by laminating a plurality of tubes (20) and having a plurality of passages through which a refrigerant flows;
An upper tank (3) provided so as to include the upper ends of the plurality of tubes (20) constituting the core portion (2);
A lower tank (4) provided so as to include the lower ends of the plurality of tubes (20) constituting the core portion (2);
Provided inside the lower tank (4), and divides the internal space of the lower tank into a plurality of tubes in the tube stacking direction (X) and adjusts the flow rate of the refrigerant flowing in the tube stacking direction (X). Flow rate adjusting members (410, 411, 412);
With
An oil flow passage (412b) for communicating the lower spaces in the lower tank partitioned in the tube stacking direction (X) by the flow rate adjusting member (412) is set on the bottom wall (41a) side of the lower tank. An evaporator characterized by that. In addition to the oil flow passage (412b), the flow rate adjusting member (412) includes a throttle opening (412a) for adjusting the flow rate of the refrigerant flowing in the tube stacking direction (X) in the lower tank (4). ) Is formed,
The evaporator according to claim 1, wherein the oil flow passage (412b) is provided at a position lower than the throttle opening (412a). A plurality of the flow rate adjusting members (410, 411, 412) are arranged in the lower tank (4) with an interval in the tube stacking direction (X),
The throttle opening (412a) formed in the flow rate adjusting member (412) located on the downstream side of the refrigerant flow is the throttle opening formed in the flow rate adjusting member (411) located on the upstream side. The cross-sectional area is smaller than (411a),
The evaporator according to claim 2, wherein the oil flow passage (412b) is set in at least one of the plurality of flow rate adjusting members (410, 411, 412).   Of the plurality of flow rate adjusting members (410, 411, 412), the oil flow passage (412b) is set in the flow rate adjusting member (412) located on the most downstream side. The evaporator according to claim 3.   The oil flow passage (412b) is a hole formed by a bottom wall (41a) of the lower tank and a part (412c) of an outer edge of the flow rate adjusting member. The evaporator according to any one of 4.   The oil flow passages (64b1, 64b2, 64b3) are formed in a row in the air flow direction (Z) on the bottom wall (41a) side of the lower tank. The evaporator according to claim 5.

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