【０００１】
【産業上の利用分野】
本発明は、車両空調用に供して好適な圧縮機に係り、主として単頭形のピストンを内装した多気筒往復動型圧縮機に関する。
【０００２】
【従来の技術】
従来この主の圧縮機として、固定斜板を備えた定容量型圧縮機や傾角変位可能な回転斜板を備えた可変容量型圧縮機が知られている。
これらの圧縮機は、図５及び図６に例示するように、複数のボア２を並設したシリンダブロック１と、各ボア２に対応した吸入口３及び吐出口４を有する弁板５と、吸入弁３ａ及び吐出弁４ａを装着した同弁板５を挟んでシリンダブロック１の外端を閉塞するシリンダヘッド６とを備えており、各ボア２に挿嵌されたピストン７が所定の位相差をもって往復動するように構成されている。そしてシリンダヘッド６の内部には、中央域に吐出室８、同外周域には吸入室９が画設されており、吐出室８は吐出フランジ１０の吐出孔１１に連通され、吸入室９は吸入フランジ１２の吸入孔１３と連通されている。
【０００３】
したがって、圧縮機が駆動されると、蒸発器に接続された回路配管から吸入孔１３を通って吸入室９に導かれた冷媒ガスは、各吸入口３を経て順次吸入過程にあるボア２に吸入され、圧縮された冷媒ガスは各吐出口４から順次吐出室８に吐出されて、吐出孔１１を経由凝縮器に接続された回路配管へと送出される。
【０００４】
【発明が解決しようとする課題】
ところが、図５に明示されているごとく、一般に吸入室の形状は設計上の制約などから複雑なものとなることが多く、吸入室に開口する吸入孔の近傍位置と、同開口から最も離隔した位置とでは、ガス流れに伴う圧力損失により意外に大きな圧力差が生じ、例えば３０００ｒ．ｐ．ｍの回転数において、その値は０．５〜１ｋｇ／ｃｍ２ にも達する。このため、吸入孔開口部から遠隔した吸入口と対応するボアほど常に希薄な冷媒ガスを吸入することとなり、体積効率の低下ばかりでなく、これら不均一な吸入が吸入脈動に起因する関連機器の振動や騒音を増幅させる。
【０００５】
勿論、このような吸入脈動の低減対策として、吸入室を隔壁によって軸方向に仕切ることによりマフラ効果をもたせた技術（実開昭６１ー１４５８８４号）や、吸入と吐出の差こそあれ、シリンダヘッドの外端に更にカバー部材を重装して、内部に形成した円形状拡張空間の全域をマフラとして機能させるようにした技術（特開昭５６ー４４４８１号）などが提案されている。
【０００６】
しかしながら、これらの提案はいずれも圧縮機の軸方向にガス流路の容積拡張部を設ける構成であり、特に小型化の要求の強い車両空調用圧縮機では軸長の拡大に厳しい制限があるうえ、吸入弁の脈動に起因する５００〜８００Ｈｚ程度の脈動成分の減衰には、拡張型マフラに少なくとも５０ｍｍ以上の長さが必要となる全く相反した機能上の制約がある。
【０００７】
また、上述した後者の提案技術のように、シリンダヘッド端面のほぼ全域に及ぶような拡張空間をもって吸入マフラを構成しようとすれば、該拡張空間と吐出室（高温域）との隣接面積が必然的に拡大されるので、吸入ガスの加熱に基づく性能低下など新たな不具合を誘起することにもなりかねない。
本発明は、圧力損失に基づく吸入脈動並びに吸入弁の脈動に基づく吸入脈動を同時に減衰させることを、解決すべき技術課題とするものである。
【０００８】
【課題を解決するための手段】
本発明は上記課題解決のため、複数のボアを並設したシリンダブロックと、該各ボアに対応した吸入口及び吐出口を有する弁板と、吸入弁及び吐出弁を装着した該弁板を挟んで上記シリンダブロックの外端を閉塞するシリンダヘッドと、該シリンダヘッド内に画設された吸入室及び吐出室とを備え、上記各ボアに挿嵌されたピストンが所定の位相差をもって往復動する形式の圧縮機において、冷凍回路に接続される吸入フランジと、機体軸心と直交する向きに配設するとともに、拡大した断面積をもつ拡張部と縮小した断面積をもつ縮小部とをもち、かつ一端から他端にかけて延びる吸入通路と、該吸入通路と該吸入室を連通する複数の枝孔と、からなる新規な構成を採用している。
本発明の好適な形態として、上記吸入通路は枝孔を介して吸入室内の径方向に懸隔する少なくとも二つの領域と連通せしめられている。
【０００９】
本発明の好適な形態として、上記吸入通路は枝孔を介して吸入室内の径方向に懸隔する少なくとも二つの領域と連通せしめられている。
【００１０】
【作用】
圧縮機が駆動されると、冷凍回路に接続される吸入フランジから吸入通路及びその一部をなす枝孔を介して吸入室に流入した冷媒ガスは、各枝孔からそれぞれ至近位置に開口されている吸入口を経て各ボアの円滑に吸入され、吸入室内の流路抵抗に基づく圧力損失は合理的に低減されるので、圧力損失に伴う比較的低周波成分の脈動は付随的に低減される。
【００１１】
また、上記吸入通路には拡張部と縮小部とからなる脈動減衰部が形成されており、しかも該拡張部は機体の軸心と直交する向きに延びて、圧縮機の軸長に大きな影響をもたらすことなく、必要にして十分な長さを確保しうるので、吸入弁の振動に基づく比較的高周波成分の脈動も至極良好に減衰される。
【００１２】
【実施例】
以下、図１〜図４に基づいて本発明の実施例を具体的に説明する。なお、従来装置と同等の構成要素には同一の符号を付して詳細な説明は省略する。
すなわち、弁板５を挟んでシリンダブロック１の外端を閉塞するシリンダヘッド２０の側端壁にはほぼＴ字形をなす膨出部２０ａが形成されており、その内部には機体軸心と直交する向きに延びる吸入通路２１が配設されている。該吸入通路２１は図３及び図４から明らかなように、長孔形断面をもつ拡張部２１ａと円形断面の縮小部２１ｂとによって形成される脈動減衰部を有し、該拡張部２１ａ及び縮小部２１ｂの各々は、同様に吸入通路２１の一部を構成し、かつ吸入室９の底壁を貫通する枝孔２１ｃ、２１ｃ′を介して、該吸入室内９内の互いに懸隔する二つの領域と連通せしめられている。なお、上記拡張部２１ａの開口端はシール要素２２を容して吸入フランジ２３により覆蓋されており、上記吸入通路２１に連なる吸入フランジ２３の吸入孔２４は、図示しない蒸発器から延設される吸入系冷凍回路と接続されている。
【００１３】
したがって、圧縮機が駆動されて順次吸入行程へと移行する各ボア２には、対応する吸入口３及び該吸入口３から至近位置に開口されている各枝孔２１ｃ、２１ｃ′を介して冷媒ガスが円滑に吸入され、吸入室９内の流路抵抗に基づく圧力損失は合理的に低減されるので、圧力損失に伴う比較的低周波成分の脈動は付随的に低減される。
【００１４】
とくに本発明における上記吸入通路２１には、拡張部２１ａと縮小部２１ｂとからなる脈動減衰部がマフラとして機能しており、しかも該拡張部２１ａは機体の軸心と直交する向きに延びて、圧縮機の軸長にさほど大きな影響をもたらすことなく、必要にして十分な長さを確保しうるので、吸入弁３ａの振動に基づく比較的高周波成分の脈動も併せて良好に減衰される。
【００１５】
なお、上述の実施例では、冷媒ガスが吸入室９内の互いに懸隔する二つの領域と連通する枝孔２１ｃ、２１ｃ′を介して吸入される構成について説明したが、吸入通路２１の一部から更に増設した枝孔を通じて吸入室９内の他の領域とも連通させれば、各ボア２に吸入される冷媒ガスの圧力格差を一層均斉化させることができる。また、吸入室９の深さを局部的に拡大し、その内周壁に吸入通路２１の縮小部２１ｂを直接開口させて図示枝孔２１ｃ′を省略するように構成することもできる。
【００１６】
【発明の効果】
以上、詳述したように本発明は、冷凍回路に接続される吸入フランジと、機体軸心と直交する向きに配設するとともに、拡大した断面積をもつ拡張部と縮小した断面積をもつ縮小部とをもち、かつ一端から他端にかけて延びる吸入通路と、該吸入通路と該吸入室を連通する複数の枝孔と、からなるものであるから、各ボアに吸入される冷媒ガスの圧力格差が均斉化されて、圧力損失に基づく吸入脈動が合理的に低減されると同時に、吸入通路に形成した脈動減衰部の機能により、吸入弁の振動に伴って生じる異質の脈動成分も至極良好に減衰させることができる。
【図面の簡単な説明】
【図１】本発明の実施例に係る圧縮機のリヤハウジングを示す断面側面図。
【図２】本発明の実施例に係る圧縮機の吸入通路を示す断面正面図。
【図３】本発明の実施例に係る圧縮機の吸入通路を示す側面図。
【図４】本発明の実施例に係る圧縮機の吸入通路を示す図３のＡーＡ線矢視図。
【図５】従来圧縮機のリヤハウジングを示す断面側面図。
【図６】従来圧縮機のリヤハウジングを示す断面正面図。
【符号の説明】
１はシリンダブロック、２はボア、３は吸入口、３ａは吸入弁、５は弁板、８は吐出室、９は吸入室、２０はシリンダヘッド、２１は吸入通路、２１ａは拡張部、２１ｂは縮小部、２１ｃ、２１ｃ′は枝孔、２３は吸入フランジ、２４は吸入孔[0001]
[Industrial applications]
The present invention relates to a compressor suitable for use in vehicle air conditioning, and more particularly to a multi-cylinder reciprocating compressor including a single-headed piston.
[0002]
[Prior art]
Conventionally, as this main compressor, a constant displacement compressor having a fixed swash plate and a variable displacement compressor having a rotating swash plate capable of tilting displacement are known.
As illustrated in FIGS. 5 and 6, these compressors include a cylinder block 1 having a plurality of bores 2 arranged side by side, a valve plate 5 having a suction port 3 and a discharge port 4 corresponding to each bore 2, A cylinder head 6 for closing the outer end of the cylinder block 1 with the valve plate 5 having the suction valve 3a and the discharge valve 4a interposed therebetween, and a piston 7 inserted into each bore 2 having a predetermined phase difference. It is configured to reciprocate with. Inside the cylinder head 6, a discharge chamber 8 is defined in a central area and a suction chamber 9 is defined in the outer peripheral area. The discharge chamber 8 communicates with a discharge hole 11 of a discharge flange 10, and the suction chamber 9 is It communicates with the suction hole 13 of the suction flange 12.
[0003]
Therefore, when the compressor is driven, the refrigerant gas guided from the circuit pipe connected to the evaporator to the suction chamber 9 through the suction hole 13 passes through each suction port 3 to the bore 2 in the suction process. The sucked and compressed refrigerant gas is sequentially discharged from each of the discharge ports 4 to the discharge chamber 8, and is discharged to a circuit pipe connected to the condenser via the discharge hole 11.
[0004]
[Problems to be solved by the invention]
However, as clearly shown in FIG. 5, in general, the shape of the suction chamber is often complicated due to design restrictions and the like, and the position near the suction hole that opens to the suction chamber is the most distant from the opening. Position, an unexpectedly large pressure difference occurs due to the pressure loss associated with the gas flow, e.g. p. At a rotational speed of m, the value reaches 0.5-1 kg / cm 2 . For this reason, the bore corresponding to the suction port remote from the suction hole opening always sucks in the leaner refrigerant gas, which not only lowers the volumetric efficiency but also causes the uneven suction of the related equipment caused by the suction pulsation. Amplifies vibration and noise.
[0005]
Of course, as a countermeasure to reduce such suction pulsation, there is a technique of giving a muffler effect by partitioning the suction chamber in the axial direction by a partition wall (Japanese Utility Model Application Laid-Open No. 61-145883), and there is a difference between suction and discharge. (Japanese Patent Application Laid-Open No. Sho 56-44481) has been proposed in which a cover member is further mounted on the outer end of the device to make the entire area of the circular expansion space formed therein function as a muffler.
[0006]
However, each of these proposals has a configuration in which the volume expansion portion of the gas flow path is provided in the axial direction of the compressor, and especially in a vehicle air-conditioning compressor, which is required to be miniaturized, there is a strict restriction on the expansion of the shaft length. On the other hand, the attenuation of the pulsation component of about 500 to 800 Hz caused by the pulsation of the suction valve has completely contradictory functional restrictions that require the length of the expandable muffler to be at least 50 mm or more.
[0007]
Further, if the suction muffler is configured to have an expansion space that covers almost the entire area of the end face of the cylinder head as in the latter proposed technology described above, the area adjacent to the expansion space and the discharge chamber (high-temperature region) is inevitably increased. This may cause new problems such as performance degradation due to heating of the suction gas.
An object of the present invention is to simultaneously attenuate suction pulsation based on pressure loss and suction pulsation based on suction valve pulsation.
[0008]
[Means for Solving the Problems]
In order to solve the above problems, the present invention sandwiches a cylinder block having a plurality of bores arranged side by side, a valve plate having a suction port and a discharge port corresponding to each bore, and the valve plate having a suction valve and a discharge valve mounted thereon. A cylinder head for closing the outer end of the cylinder block, and a suction chamber and a discharge chamber defined in the cylinder head, and the pistons inserted into the respective bores reciprocate with a predetermined phase difference. has the form of a compressor, a suction flange connected to the refrigeration circuit, as well as arranged in a direction perpendicular to the machine body axis, and a reduction unit having a cross sectional area reduced and extended portion having a larger cross-sectional area In addition, a novel configuration including a suction passage extending from one end to the other end, and a plurality of branch holes communicating the suction passage and the suction chamber is adopted.
According to a preferred embodiment of the present invention, the suction passage communicates with at least two radially suspended regions in the suction chamber through the branch holes.
[0009]
According to a preferred embodiment of the present invention, the suction passage communicates with at least two radially suspended regions in the suction chamber through the branch holes.
[0010]
[Action]
When the compressor is driven, the refrigerant gas flowing from the suction flange connected to the refrigeration circuit to the suction chamber through the suction passage and the branch hole forming a part thereof is opened to the nearest position from each branch hole. Smooth suction of each bore through the suction port, and the pressure loss based on the flow path resistance in the suction chamber is reduced rationally, so the pulsation of relatively low-frequency components due to the pressure loss is reduced accompanyingly .
[0011]
Further, a pulsation damping portion including an expansion portion and a reduction portion is formed in the suction passage, and the expansion portion extends in a direction orthogonal to the axis of the machine body, and greatly affects the axial length of the compressor. Without causing this, a necessary and sufficient length can be ensured, so that the pulsation of the relatively high-frequency component due to the vibration of the suction valve is extremely well attenuated.
[0012]
【Example】
Hereinafter, an embodiment of the present invention will be described in detail with reference to FIGS. Note that the same components as those of the conventional device are denoted by the same reference numerals, and detailed description thereof will be omitted.
That is, a substantially T-shaped bulging portion 20a is formed on the side end wall of the cylinder head 20 that closes the outer end of the cylinder block 1 with the valve plate 5 interposed therebetween, and the inside thereof is orthogonal to the body axis. A suction passage 21 extending in the direction is provided. As is apparent from FIGS. 3 and 4, the suction passage 21 has a pulsation damping portion formed by an extended portion 21a having an elongated cross section and a reduced portion 21b having a circular cross section. Each of the portions 21b similarly constitutes a part of the suction passage 21 and, via branch holes 21c, 21c 'penetrating the bottom wall of the suction chamber 9, two regions suspended in the suction chamber 9 from each other. It is communicated with. The opening end of the expansion portion 21a is covered by a suction flange 23 containing a sealing element 22, and a suction hole 24 of the suction flange 23 connected to the suction passage 21 extends from an evaporator (not shown). Connected to the suction system refrigeration circuit.
[0013]
Therefore, each of the bores 2 that are sequentially driven to move to the suction stroke by driving the compressor is provided with the refrigerant through the corresponding suction port 3 and the branch holes 21 c and 21 c ′ opened from the suction port 3 to the nearest position. Since the gas is smoothly sucked and the pressure loss based on the flow path resistance in the suction chamber 9 is reduced rationally, the pulsation of relatively low frequency components caused by the pressure loss is also reduced.
[0014]
In particular, in the suction passage 21 of the present invention, a pulsation damping portion including an expansion portion 21a and a reduction portion 21b functions as a muffler, and the expansion portion 21a extends in a direction perpendicular to the axis of the body, Since a necessary and sufficient length can be secured without significantly affecting the shaft length of the compressor, pulsation of a relatively high frequency component due to the vibration of the suction valve 3a is also satisfactorily attenuated.
[0015]
In the above-described embodiment, the configuration has been described in which the refrigerant gas is sucked through the branch holes 21c and 21c 'communicating with the two mutually suspended regions in the suction chamber 9, but from a part of the suction passage 21. Further, by communicating with other areas in the suction chamber 9 through the additional branch holes, the pressure difference of the refrigerant gas sucked into each bore 2 can be further equalized. Alternatively, the depth of the suction chamber 9 may be locally increased, and the reduced portion 21b of the suction passage 21 may be directly opened on the inner peripheral wall thereof to omit the illustrated branch hole 21c '.
[0016]
【The invention's effect】
While the present invention as described in detail has a suction flange connected to the refrigeration circuit, as well as arranged in a direction perpendicular to the machine body axis, the cross-sectional area of reduced and extended portion having a larger cross-sectional area A suction passage having a reduced portion and extending from one end to the other end, and a plurality of branch holes communicating the suction passage and the suction chamber, the pressure of the refrigerant gas sucked into each bore; The gap is equalized, and suction pulsation due to pressure loss is reduced rationally, and at the same time, the function of the pulsation damping section formed in the suction passage minimizes pulsation components that are different due to vibration of the suction valve. Can be attenuated.
[Brief description of the drawings]
FIG. 1 is a sectional side view showing a rear housing of a compressor according to an embodiment of the present invention.
FIG. 2 is a sectional front view showing a suction passage of the compressor according to the embodiment of the present invention.
FIG. 3 is a side view showing a suction passage of the compressor according to the embodiment of the present invention.
FIG. 4 is a view taken along line AA of FIG. 3 showing a suction passage of the compressor according to the embodiment of the present invention.
FIG. 5 is a sectional side view showing a rear housing of a conventional compressor.
FIG. 6 is a sectional front view showing a rear housing of the conventional compressor.
[Explanation of symbols]
1 is a cylinder block, 2 is a bore, 3 is a suction port, 3a is a suction valve, 5 is a valve plate, 8 is a discharge chamber, 9 is a suction chamber, 20 is a cylinder head, 21 is a suction passage, 21a is an expansion portion, 21b Is a reduced portion, 21c and 21c 'are branch holes, 23 is a suction flange, and 24 is a suction hole.
