JP2008111376A - Ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the manufacturing cost of an ejector by forming a main structural portion of a nozzle with a resin. <P>SOLUTION: In the ejector 40, the main structural portion such as a body 46 and the nozzle 41 are formed with a resin material. The nozzle 41 requires high working accuracy for an inner wall shape exposed to working fluid, in other words, requires high dimensional accuracy and predetermined surface roughness. In addition, in the ejector 40 for an ejector type refrigerating cycle, since speed energy is converted into pressure energy at boosting portions 42, 43 while mixing a refrigerant injected from the nozzle 41 and a refrigerant sucked from an evaporator 30, high working accuracy for an inner wall shape of the boosting portions 42, 43 is also required similar to the inner wall shape of the nozzle 41. Therefore, conventionally and generally, the nozzle 41 is manufactured by electrical discharge machining and wire cutting, and the boosting portions 42, 43 are manufactured by cutting work. Compared to such a conventional ejector, reduction of the manufacturing cost of an ejector 40 becomes possible by forming the main structural portion of the body 46 and the nozzle 41 with the resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an ejector (see JIS Z 8126 number 2.1.2.3, etc.) that is a momentum transporting pump that transports fluid by the entrainment of working fluid ejected at high speed, and a pump that circulates refrigerant It is effective when applied to a refrigeration apparatus that employs an ejector as means (hereinafter referred to as an ejector-type refrigeration cycle).

As a conventional technique for reducing the manufacturing cost of an ejector, there is Patent Document 1 below. In this method, the nozzle is made of sintered metal, and the pressurizing part (mixing part and diffuser part) is manufactured by subjecting a metal pipe to plastic working.
JP 2003-326196 A

  The factor that greatly affects the ejector performance is the coaxiality of the nozzle with respect to the mixing portion. To manage this coaxiality, it is desirable that the boosting portion including the mixing portion and the suction portion that holds the nozzle be formed integrally. However, in the case of the above-described prior art, the suction portion has a suction port extending in one direction and has a non-uniform shape in the circumferential direction. is there.

  The present invention has been made paying attention to such problems existing in the prior art, and an object thereof is to provide a novel ejector capable of reducing the manufacturing cost.

  In order to achieve the above object, the present invention employs the following technical means. That is, the invention according to claim 1 is an ejector that is a momentum transporting pump that transports fluid by the entrainment action of the working fluid ejected at high speed from the nozzle (41) disposed in the body (46), (46) or the main structure of the nozzle (41) is formed of a resin material.

  The nozzle (41) of the ejector (40) is for depressurizing the working fluid to accelerate the fluid, and the inner wall shape exposed to the working flow requires high machining accuracy, that is, high dimensional accuracy and predetermined surface roughness. To do. Further, in the ejector (40) for the ejector type refrigeration cycle, the pressure energy is converted into the pressure energy while mixing the refrigerant injected from the nozzle (41) and the refrigerant sucked from the evaporator (30) in the pressurizing sections (42, 43). Therefore, the inner wall shape of the booster (42, 43) also requires high machining accuracy, like the inner wall shape of the nozzle (41).

  For this reason, conventionally, the nozzle (41) is generally manufactured by electric discharge machining or wire cutting, and the booster (42, 43) is manufactured by cutting. Compared to such a conventional case, the manufacturing cost of the ejector (40) can be reduced by forming the main structural portion of the body (46) or the nozzle (41) with resin.

  Further, in the invention according to claim 2, in the ejector according to claim 1, the body (46) is formed of a resin material, and the metal member (47) is inserted into the portion holding the nozzle (41). It is characterized by being molded. FIG. 11 is a schematic diagram of the ejector (40A) for explaining a problem when the body (46A) and the nozzle (41A) are both made of resin in the conventional ejector structure.

  When the resin nozzle (41A) is press-fitted and held in the resin body (46A) as in the conventional metal ejector (40), the resin material creeps at the press-fitting portion A1, and the holding force. May become weaker, causing axial misalignment, deterioration of coaxiality, leakage of working fluid, and in the worst case, the nozzle (41A) may fall off the body (46A).

  However, according to the second aspect of the invention, even when the body (46) is made of resin, the holding force after press-fitting is ensured by inserting the metal member (47) into the portion holding the nozzle (41). As a result, it is possible to prevent problems such as axial displacement, deterioration of coaxiality, leakage of working fluid, and nozzle (41A) dropping off from the body (46A).

  Moreover, in invention of Claim 3, in the ejector of Claim 1, while forming the nozzle (41) with the resin material, the metal member (45) is provided in the part hold | maintained at a body (46). It is characterized by insert molding. According to the third aspect of the invention, even when the nozzle (41) is made of resin, the holding force after press-fitting is ensured by inserting the metal member (45) into the portion held by the body (46). As a result, it is possible to prevent problems such as axial displacement, deterioration of coaxiality, leakage of working fluid, and nozzle (41A) dropping off from the body (46A).

  According to a fourth aspect of the present invention, in the ejector according to the first aspect, the nozzle (41) is formed of a resin material, and the metal member (44) is insert-molded in the path portion of the driving flow. It is characterized by having. When the nozzle (41) is made of resin, the fluid flows at a high speed particularly in the portion after the throat portion (411) (A2 portion in FIG. 11). Therefore, in a material having low hardness such as resin, wear is caused by fluid friction. Therefore, there is a possibility that the shape is deviated from the optimum shape and the performance is deteriorated. However, according to the fourth aspect of the present invention, it is possible to ensure high dimensional accuracy and predetermined surface roughness of the drive channel portion.

  The invention according to claim 5 is characterized in that, in the ejector according to claim 4, the metal member (44) is formed by plastic working. In addition, as a method of plastically processing the metal member (44) in the drive flow path portion, there is a method of subjecting the pipe material to swaging processing, press processing, spinning processing, spatula processing, or the like (see JIS B 0122). According to the fifth aspect of the present invention, the drive channel portion can be manufactured in a short time while maintaining high processing accuracy, and thus the manufacturing cost of the ejector (40) can be reduced. .

  Moreover, in invention of Claim 6, in the ejector of any one of Claim 2 thru | or 5, it is a slip prevention shape in the part joined with the resin material of a metal member (44, 45, 47). (48). According to the sixth aspect of the present invention, the metal member (44, 45, 47) can be prevented from shifting with respect to the body (46) and the nozzle (41) formed of a resin material, and the mixing section ( It becomes easy to ensure the coaxiality of the nozzle (41) with respect to 42).

  The invention described in claim 7 is characterized in that, in the ejector according to claim 1, a metal nozzle (41) is insert-molded in a body (46) formed of a resin material. Yes. This eliminates the taper of the suction portion, and allows the metal nozzle (41) to be insert-molded into the body (46) when the resin body (46) is molded.

  According to the seventh aspect of the present invention, the nozzle (41) is made of metal, but a member other than the body (46) and the nozzle (41), for example, the metal member (44, 45, 47) is not necessary, and the process of press-fitting the insert-shaped body (46) and the nozzle (41) is not required, which simplifies the manufacturing process, thereby reducing the manufacturing cost of the ejector (40). It becomes possible.

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

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described in detail with reference to FIGS. FIG. 1 is a schematic diagram of an ejector refrigeration cycle according to an embodiment of the present invention, and FIG. 2 is a ph diagram of the ejector refrigeration cycle of FIG. FIG. 3 is a schematic diagram of the ejector 40B according to the first embodiment of the present invention.

  In the present embodiment, the ejector 40 according to the present invention is applied to an ejector-type refrigeration cycle of a vehicle air conditioner, and carbon dioxide refrigerant is used as a working fluid in the present embodiment. The compressor 10 is a known variable displacement type compressor 10 that obtains power from a vehicle travel engine (not shown) and sucks and compresses refrigerant.

  The radiator 20 is a high-pressure side heat exchanger that cools the refrigerant by exchanging heat between the refrigerant discharged from the compressor 10 and air outside the vehicle (outside air). The evaporator 30 is a low-pressure heat exchanger that cools the air blown into the vehicle interior by heat-exchanging the air blown into the vehicle interior and the gas-liquid two-phase refrigerant to evaporate the gas-liquid two-phase refrigerant. In addition, the ejector 40 sucks the gas-phase refrigerant evaporated in the evaporator 30 by decompressing and expanding the refrigerant, and converts the expansion energy into pressure energy to increase the suction pressure of the compressor 10.

  As shown in FIG. 1, the ejector 40 converts the pressure energy of the inflowing high-pressure refrigerant into velocity energy to cause the refrigerant to be isentropically decompressed and expanded, and a high-speed refrigerant flow ejected from the nozzle 41. While sucking the gas-phase refrigerant evaporated in the evaporator 30, the mixing unit 42 that mixes the refrigerant flow ejected from the nozzle 41 and the refrigerant ejected from the nozzle 41 and the refrigerant sucked from the evaporator 30 are mixed. It comprises a diffuser section 43 that increases the pressure of the refrigerant by converting velocity energy into pressure energy.

  At this time, in the mixing unit 42, the driving flow and the suction flow are mixed so that the sum of the momentum of the driving flow and the momentum of the suction flow is preserved. ) Will rise. On the other hand, in the diffuser portion 43, the velocity energy (dynamic pressure) of the refrigerant is converted into pressure energy (static pressure) by gradually increasing the cross-sectional area of the passage. Therefore, in the ejector 40, the mixing portion 42 and the diffuser portion. The refrigerant pressure is increased by both of 43.

  Therefore, hereinafter, the mixing unit 42 and the diffuser unit 43 are collectively referred to as a boosting unit. In the present embodiment, a Laval nozzle (fluid engineering (The University of Tokyo Press), which has a throat 411 (see FIG. 11) in which the passage area is most reduced in the middle of the passage in order to accelerate the speed of the refrigerant ejected from the nozzle 41 to the speed of sound or more. )) Is adopted, but it goes without saying that a tapered nozzle may be adopted.

  In addition, the gas-liquid separator 50 in FIG. 1 is a gas-liquid separation unit that stores the liquid-phase refrigerant by separating the refrigerant flowing into the gas-phase refrigerant and the liquid-phase refrigerant while the refrigerant flowing out from the ejector 40 flows in. The gas-phase refrigerant outlet of the gas-liquid separator 50 is connected to the suction side of the compressor 10, and the liquid-phase refrigerant outlet is connected to the inlet side of the evaporator 30. The throttle 60 is a decompression unit that decompresses the liquid-phase refrigerant that has flowed out of the gas-liquid separator 50.

  And in this embodiment, as shown in FIG. 2, the high pressure refrigerant | coolant which flows in into the nozzle 41 with the compressor 10 is pressure | voltage-risen more than the critical pressure of a refrigerant | coolant. The symbol indicated by ● in FIG. 2 indicates the state of the refrigerant at the symbol position indicated by ● in FIG. Next, the general operation of the ejector refrigeration cycle will be described (see FIG. 2).

  The refrigerant discharged from the compressor 10 is circulated to the radiator 20 side. As a result, the refrigerant cooled by the radiator 20 is isentropically decompressed and expanded at the nozzle 41 of the ejector 40 and flows into the mixing unit 42 at a speed equal to or higher than the speed of sound. Then, the refrigerant evaporated in the evaporator 30 is sucked into the mixing unit 42 by the pumping action accompanying the entrainment action of the high-speed refrigerant flowing into the mixing unit 42.

  For this reason, the refrigerant on the low-pressure side circulates in the order of the gas-liquid separator 50 → the throttle 60 → the evaporator 30 → the ejector 40 (pressure increase unit) → the gas-liquid separator 50. On the other hand, the refrigerant sucked from the evaporator 30 (suction flow) and the refrigerant blown from the nozzle 41 (driving flow) are mixed by the mixing unit 42 and the dynamic pressure thereof is converted to static pressure by the diffuser unit 43. Return to the gas-liquid separator 50.

  Next, a specific structure of the ejector 40B of this embodiment will be described with reference to FIG. The ejector 40B of the present embodiment is configured by press-fitting a nozzle 41 made of metal into a body 46B made of resin as in the conventional case. The body 46B is formed, for example, by injection molding of a phenol resin, and a metal body inner insert (a metal member referred to in the present invention) 47 is insert-molded in a portion that holds the nozzle 41.

  A plurality of recesses (displacement prevention shapes referred to in the present invention) 48 for preventing the occurrence of deviation from the resin material are formed in a portion of the outer peripheral surface of the body inner insert 47 to be joined with the resin material. In addition, this deviation prevention shape may be knurling etc. which were given to the outer peripheral surface of insert, for example, and does not limit a shape.

  The nozzle 41 may be manufactured by electric discharge machining or wire cutting of a metal member such as stainless steel, or a metal (for example, stainless steel) powder is filled in a mold to change the shape of the nozzle 41. After compression molding, the nozzle may be manufactured from a so-called sintered metal sintered at a high temperature or high pressure.

  Next, features and effects of this embodiment will be described. First, the main structure portion of the body 46 is formed of a resin material. In the ejector 40 for the ejector-type refrigeration cycle, the speed energy is converted into pressure energy while mixing the refrigerant injected from the nozzle 41 and the refrigerant sucked from the evaporator 30 in the pressure-increasing parts 42 and 43 of the body 46. Like the inner wall shape of the nozzle 41, the inner wall shapes of 42 and 43 require high machining accuracy.

  For this reason, generally, the boosters 42 and 43 are manufactured by cutting. Compared to such a conventional case, the manufacturing cost of the ejector 40B can be reduced by forming the main structural portion of the body 46B from resin. Further, the entire ejector 40B can be reduced in weight.

  In addition, the body 46B is formed of a resin material, and the body inner insert 47 is insert-molded in a portion that holds the nozzle 41. According to this, even when the body 46B is made of resin, the holding force after press-fitting can be secured by inserting the body inner insert 47 in the portion that holds the nozzle 41, the axial displacement, the coaxiality It is possible to prevent problems such as deterioration of the working fluid, leakage of the working fluid, and the nozzle 41 falling off the body 46B.

  Further, the body inner insert 47 is provided with a recess 48 as a displacement preventing shape at a portion to be joined to the resin material. According to this, it can prevent that the body inner side insert 47 shifts | deviates with respect to the body 46B formed with the resin material, and it becomes easy to ensure the coaxiality of the nozzle 41 with respect to the mixing part 42. FIG.

(Second Embodiment)
FIG. 4 is a schematic diagram of an ejector 40C according to the second embodiment of the present invention. In each of the following embodiments, the same components as those in the first embodiment described above are denoted by the same reference numerals, description thereof will be omitted, and characteristic portions different from those in the above embodiment will be described. The ejector 40C of the present embodiment is configured by press-fitting a nozzle 41B formed of resin into a body 46 formed of metal as in the prior art.

  The nozzle 41B is formed by, for example, injection molding of a phenol resin, and a metal nozzle outer insert (a metal member in the present invention) 45 is insert-molded in a portion held by the body 46 so that a path of driving flow is obtained. A drive flow portion insert (a metal member referred to in the present invention) 44A is insert-molded in the portion.

  In addition, in the portion that joins the resin material on the inner peripheral surface of the nozzle outer insert 45 and the outer peripheral surface of the drive flow portion insert 44, a concave portion 48 for preventing the occurrence of deviation from the resin material is provided, as in the first embodiment. Multiple locations are formed. This shift prevention shape is similarly applied to the metal member that is insert-molded in the resin material in each of the following embodiments. The body 46 may be manufactured by cutting a metal member such as stainless steel, or may be manufactured by plastic processing a metal (for example, stainless steel) tube material.

  Next, features and effects of this embodiment will be described. First, the main structure of the nozzle 41 is formed of a resin material. The nozzle 41 of the ejector 40 accelerates the fluid by depressurizing the working fluid, and the inner wall shape exposed to the working flow requires high machining accuracy, that is, high dimensional accuracy and predetermined surface roughness. For this reason, the nozzle 41 is generally manufactured by electric discharge machining or wire cutting.

  Compared to such a conventional case, the manufacturing cost of the ejector 40 can be reduced by forming the main structural portion of the nozzle 41B with resin. Further, the entire ejector 40C can be reduced in weight.

  In addition, the nozzle 41B is formed of a resin material, the nozzle outer insert 45 is insert-molded in the portion held by the body 46, and the driving flow portion insert 44 is insert-molded in the path portion of the driving flow. According to this, even when the nozzle 41B is made of resin, the holding force after press-fitting can be secured by inserting the nozzle outer insert 45 into the portion held by the body 46, and the axial displacement, coaxial It is possible to prevent problems such as deterioration of the degree, leakage of the working fluid, and dropping of the nozzle 41B from the body 46.

  In addition, when the nozzle 41B is made of resin, the fluid flows at a high speed particularly in the portion after the throat portion 411 (A2 portion in FIG. 11). There may be a problem that it is out of shape and causes performance degradation. However, according to this, high dimensional accuracy and predetermined surface roughness of the drive channel portion can be ensured.

(Third embodiment)
FIG. 5 is a schematic view of an ejector 40D according to the third embodiment of the present invention. The ejector 40D of this embodiment is configured by press-fitting a nozzle 41B made of resin into a body 46B made of resin. The body 46B is formed of a resin material as in the first embodiment, and a metal body inner insert (a metal member referred to in the present invention) 47 is insert-molded in a portion that holds the nozzle 41B.

  In addition, the nozzle 41B is formed of a resin material as in the second embodiment, and a metal nozzle outer insert 45 is insert-molded into a portion held by the body 46B, so that a drive flow path portion is formed. Insert-molds the drive flow portion insert 44A. Thus, the main structural parts of both the body 46 and the nozzle 41 are formed of a resin material. Thereby, the whole ejector 40D can be further reduced in weight.

(Fourth embodiment)
FIG. 6 is a schematic diagram of an ejector 40E in the fourth embodiment of the present invention. Features different from the above-described third embodiment will be described. In this embodiment, in the nozzle 41 </ b> C formed of resin, the driving flow portion insert 44 </ b> B is only the portion after the throat portion 411. According to this, it is possible to further reduce the manufacturing cost of the ejector 40E because less processing of the drive flow portion insert 44B is required. Further, the entire ejector 40E can be further reduced in weight.

(Fifth embodiment)
FIG. 7 is a schematic diagram of an ejector 40F in the fifth embodiment of the present invention. A different characteristic part from each embodiment mentioned above is demonstrated. In this embodiment, in the nozzle 41D formed of resin, the driving flow portion insert 44C is formed by plastic working. FIG. 8 is a schematic diagram of an ejector 40G for explaining a problem when using a nozzle 44C that has only been plastically processed.

  In this way, when the nozzle 44C manufactured by plastic working is used as it is, the outer shape of the nozzle having a substantially uniform plate thickness is formed along the flow path, so that the outer shape of the nozzle 44C is increased in the suction flow path. As the pressure increases, the pressure loss increases (A3 in FIG. 8), and the ejector performance decreases. On the other hand, this problem can be solved by insert-molding a metal driving flow portion insert 44C obtained by plastic processing of the driving flow passage portion of the nozzle 41D.

  As a method of plastically processing the drive flow portion insert 44C, there is a method of performing a swaging process, a press process, a spinning process, a spatula process, or the like (see JIS B 0122) on the pipe material. According to this, the drive flow path portion can be manufactured in a short time while maintaining high processing accuracy, and thus the manufacturing cost of the ejector 40F can be reduced.

(Sixth embodiment)
FIG. 9 is a schematic diagram of an ejector 40H in the sixth embodiment of the present invention. A different characteristic part from each embodiment mentioned above is demonstrated. In this embodiment, a metal nozzle 41 is insert-molded in a body 46A formed of a resin material. This eliminates the taper of the suction part and allows the nozzle 41 formed of metal to be insert-molded into the body 46A when molding the resin body 46A.

  (A) of FIG. 10 is a manufacturing process diagram of the ejectors 40D to F of FIGS. 5 to 7, and (b) is a manufacturing process diagram of the ejector 40H of FIG. As can be seen from the comparison in the process diagrams, in the ejectors 40D to 40F that are presupposed to press fit, body insert molding (P1), nozzle driven flow tube section cutting (or plastic) processing (P2), and insert molding (P3). ) Finally, press fitting assembly (P4) of the body and the nozzle and four manufacturing processes are required. On the other hand, in the ejector 40H on the premise of insert molding, it can be seen that the manufacturing process is greatly simplified only by cutting (P1) and insert molding (P2) of the nozzle 41.

  According to this, the nozzle 41 is made of metal, but the members other than the body 46A and the nozzle 41, for example, the drive flow part insert 44, the nozzle outer insert 45, and the body inner insert 47 for insert molding described above become unnecessary. Since the process of press-fitting the insert-shaped body 46 and the nozzle 41 is not required and the manufacturing process is simplified, the manufacturing cost of the ejector 40 can be reduced.

(Other embodiments)
In the above-described embodiment, the refrigeration cycle is such that the liquid-phase refrigerant flowing out from the gas-liquid separator 50 is evaporated by the evaporator 30 and then sucked into the ejector 40. However, the present invention is limited to the above-described embodiment. Instead of this, the refrigerant flow is branched between the radiator 20 and the ejector 40 to form a branch circulation path (not shown) that guides the refrigerant flow to be sucked into the ejector 40, and the evaporator 30 is disposed in the branch circulation path. It may be what you did.

  Moreover, the refrigerating cycle which arrange | positioned the 2nd evaporator part which evaporates a refrigerant | coolant and exhibits cooling capacity in the refrigerant | coolant discharge side of the ejector 40 may be sufficient. In the above-described embodiment, the ejector 40 has a fixed throttle opening. However, the ejector 40 may be configured as a variable ejector that variably controls the throttle opening of the nozzle 41 with a needle (not shown).

It is a mimetic diagram of an ejector type refrigerating cycle concerning an embodiment of the present invention. FIG. 2 is a ph diagram of the ejector refrigeration cycle of FIG. 1. It is a schematic diagram of the ejector 40B in 1st Embodiment of this invention. It is a schematic diagram of the ejector 40C in 2nd Embodiment of this invention. It is a schematic diagram of ejector 40D in 3rd Embodiment of this invention. It is a schematic diagram of the ejector 40E in 4th Embodiment of this invention. It is a schematic diagram of the ejector 40F in 5th Embodiment of this invention. It is a mimetic diagram of ejector 40G explaining a problem at the time of using nozzle 44C only plasticized. It is a schematic diagram of the ejector 40H in 6th Embodiment of this invention. (A) is a manufacturing-process figure of ejectors 40D-F of FIGS. 5-7, (b) is a manufacturing-process figure of ejector 40H of FIG. It is a schematic diagram of ejector 40A explaining the problem at the time of resin-izing with the conventional ejector structure.

Explanation of symbols

41 ... Nozzle 44 ... Drive flow part insert (metal member)
45 ... Nozzle outer insert (metal member)
46 ... Body 47 ... Body inner insert (metal member)
48 ... concave portion (shape to prevent displacement)

Claims (7)

An ejector which is a momentum transporting pump that transports fluid by the entrainment action of a working fluid ejected at high speed from a nozzle (41) disposed in a body (46);
An ejector characterized in that a main structural portion of the body (46) or the nozzle (41) is formed of a resin material.   The ejector according to claim 1, wherein the body (46) is formed of a resin material, and a metal member (47) is insert-molded in a portion that holds the nozzle (41).   The ejector according to claim 1, wherein the nozzle (41) is formed of a resin material, and a metal member (45) is insert-molded in a portion held by the body (46).   The ejector according to claim 1, wherein the nozzle (41) is formed of a resin material, and a metal member (44) is insert-molded in a path portion of the driving flow.   The ejector according to claim 4, wherein the metal member (44) is formed by plastic working.   The ejector according to any one of claims 2 to 5, wherein the metal member (44, 45, 47) is provided with a shift preventing shape (48) in a portion to be joined to the resin material. .   The ejector according to claim 1, wherein the metal nozzle (41) is insert-molded in the body (46) formed of a resin material.

Images