JP2022124033A

JP2022124033A - fuel supply system

Info

Publication number: JP2022124033A
Application number: JP2021021562A
Authority: JP
Inventors: 文宏永滝; Fumihiro NAGATAKI; 義彦本田; Yoshihiko Honda; 善和宮部; Yoshikazu Miyabe
Original assignee: Aisan Industry Co Ltd
Current assignee: Aisan Industry Co Ltd
Priority date: 2021-02-15
Filing date: 2021-02-15
Publication date: 2022-08-25

Abstract

To provide a compact fuel supply system that eliminates the necessity of providing a complicated branch passage and a check valve in a fuel supply passage for a pressure regulator and enables easier mounting design.SOLUTION: A fuel supply system 1 includes a pressure regulator 6 in the middle of one fuel supply passage 5 connecting a fuel pump 4 in a fuel tank 2 and a fuel utilization device 3. The pressure regulator 6 includes: a first chamber 22 into which fuel flows from the fuel pump 4 side; a second chamber 23 from which fuel flows out to the fuel utilization device 3 side; a recirculation outlet 27 in which surplus fuel recirculates; a first valve element 31 communicating/blocking the first chamber 22 and the recirculation outlet 27 with/from each other; a second valve element 32 communicating/blocking the first chamber 22 and the second chamber 23 with/from each other; a first energizing member 33 energizing the first valve element 31 in a valve closing direction; and a second energizing member 34 energizing the second valve element 32 in a valve opening direction. When the fuel pump 4 is in operation, the first valve element 31 and the second valve element 32 integrally move in the valve opening direction so that the fuel supply passage 5 enables communication between the first chamber 22 and the second chamber 23.SELECTED DRAWING: Figure 1

Description

本明細書に開示の技術は、内燃機関に燃料を供給する燃料供給システムに関する。 The technology disclosed in this specification relates to a fuel supply system that supplies fuel to an internal combustion engine.

特許文献１には、インジェクタに供給される燃料の圧力切換えが可能な圧力調整装置を備えた燃料供給システムが開示されている。燃料供給通路上には逆止弁が配置されている。逆止弁は、燃料ポンプユニットからインジェクタ側への燃料供給方向に開弁する一方で、逆方向には閉弁する。燃料供給通路からは分岐通路が分岐して圧力調整装置に向かい、圧力調整装置からは余剰燃料を燃料タンクに返すための燃料排出通路が設けられている。 Patent Document 1 discloses a fuel supply system provided with a pressure regulating device capable of switching the pressure of fuel supplied to an injector. A check valve is arranged on the fuel supply passage. The check valve opens in the fuel supply direction from the fuel pump unit to the injector side and closes in the opposite direction. A branch passage is branched from the fuel supply passage and directed to the pressure regulator, and a fuel discharge passage is provided from the pressure regulator for returning surplus fuel to the fuel tank.

特開２０１２－２０２３８２号公報JP 2012-202382 A

特許文献１の燃料供給システムのように、燃料供給通路と分岐通路を設けて逆止弁と圧力調整装置を配置することにより、インジェクタへ供給される燃料の圧力を調整できるとともに、燃料ポンプが停止した状態でもインジェクタ側の燃料の圧力を保持できる。しかしながら、燃料の流路が複雑になると、燃料供給システムの搭載設計の難易度が上がる傾向にある。また、圧力調整装置内と逆止弁の２か所でシール部の油密を確保することが必要になる。 As in the fuel supply system of Patent Document 1, by providing a fuel supply passage and a branch passage and arranging a check valve and a pressure adjustment device, the pressure of the fuel supplied to the injector can be adjusted and the fuel pump is stopped. The fuel pressure on the injector side can be maintained even in this state. However, when the flow path of the fuel becomes complicated, there is a tendency that the degree of difficulty in mounting design of the fuel supply system increases. In addition, it is necessary to ensure the oil-tightness of the seal portions at two locations, the inside of the pressure regulating device and the check valve.

本明細書に開示の技術が解決しようとする課題は、圧力調整装置のために燃料供給通路に複雑な分岐通路や逆止弁を設ける必要のない、コンパクトでより搭載設計が容易となる燃料供給システムを提供することにある。 The problem to be solved by the technology disclosed in this specification is to provide a compact fuel supply system that does not require a complicated branch passage or a check valve in the fuel supply passage for the pressure adjustment device, and that facilitates mounting design. It is to provide a system.

上記課題を解決するため、本明細書が開示する技術は次の手段をとる。 In order to solve the above problems, the technique disclosed in this specification takes the following measures.

第１の手段は、燃料タンクから燃料利用装置に燃料を供給する燃料供給システムにおいて、前記燃料タンク内の燃料を前記燃料利用装置に圧送する燃料ポンプと、前記燃料ポンプと前記燃料利用装置とを接続する一つの燃料供給通路と、前記燃料供給通路の途中に設けられた圧力調整装置が備えられており、前記圧力調整装置は、前記燃料ポンプ側から燃料が流入する第１室と、前記燃料利用装置側へ燃料が流出する第２室と、前記燃料タンクに余剰燃料を還流するための還流出口と、貫通孔を有し、前記第１室と前記還流出口との間を連通・遮断する第１弁体と、前記第１弁体が着座する第１弁座を有し、前記第１室と前記第２室の間を連通・遮断する第２弁体と、前記第２弁体が着座する第２弁座と、前記第１弁体を閉弁方向に付勢し、前記第１弁体と前記第２弁体が閉弁状態であるときに前記第１弁体を介して前記第２弁体を前記第２弁座に着座した状態に保持する第１付勢部材と、前記第２弁体を開弁方向に付勢する第２付勢部材と、を備え、前記燃料ポンプの作動時には、前記第１室内の燃料の圧力が高まることにより前記第１弁体と前記第２弁体が一体となって開弁方向に移動し、前記第２弁体が前記第２弁座から離れて開弁し、前記第１室と前記第２室とを通る前記燃料供給通路が連通し、燃料が燃料利用装置に供給される、燃料供給システムである。 A first means is a fuel supply system for supplying fuel from a fuel tank to a fuel utilization device, comprising: a fuel pump for pumping the fuel in the fuel tank to the fuel utilization device; and the fuel pump and the fuel utilization device. One connecting fuel supply passage and a pressure regulating device provided in the middle of the fuel supply passage are provided. The pressure regulating device includes a first chamber into which fuel flows from the fuel pump side, It has a second chamber from which fuel flows out to the utilization device side, a recirculation outlet for recirculating surplus fuel to the fuel tank, and a through hole for communicating and blocking communication between the first chamber and the recirculation outlet. a first valve body; a second valve body having a first valve seat on which the first valve body is seated; A second valve seat that is seated and biases the first valve body in the valve closing direction, and when the first valve body and the second valve body are in the valve closed state, the a first biasing member that holds the second valve body seated on the second valve seat; and a second biasing member that biases the second valve body in a valve opening direction, the fuel pump comprising: is activated, the pressure of the fuel in the first chamber increases, the first valve body and the second valve body move together in the valve opening direction, and the second valve body moves to the second valve seat. , the fuel supply passage passing through the first chamber and the second chamber communicate with each other, and fuel is supplied to the fuel utilization device.

第１の手段によると、燃料供給システムの燃料供給通路上に圧力調整装置が配置されている。圧力調整装置には第１弁体と第２弁体が備えられている。第１弁体は第１付勢部材によって閉弁方向に付勢され、第２弁体は第２付勢部材により開弁方向に付勢される。前記第１弁体と前記第２弁体が閉弁状態であるときは、第１付勢部材が前記第１弁体を介して前記第２弁体を前記第２弁座に着座した状態に保持する。この構成により、燃料ポンプが作動して燃料が第１室に流入し、第１室内の燃圧が所定の圧力より高くなると、第１室内の燃圧、第１付勢部材と第２付勢部材の付勢力の関係によって、第１弁体と第２弁体が一体となって第１弁体側に移動する。これにより、第２弁体は第２弁座から離れて開弁状態になり第１室と第２室が連通する。第１室から第２室に流入した燃料は燃料利用装置に供給される。このように圧力調整装置は燃料供給通路の一部として機能するとともに、従来必須であった逆止弁の機能をも内包する。そのため、燃料供給システムは燃料供給通路に複雑な分岐通路や逆止弁を必ずしも設ける必要がなく、コンパクトでより搭載設計が容易となる。 According to a first measure, a pressure regulator is arranged on the fuel supply passage of the fuel supply system. The pressure regulator is provided with a first valve body and a second valve body. The first valve body is biased in the valve closing direction by the first biasing member, and the second valve body is biased in the valve opening direction by the second biasing member. When the first valve body and the second valve body are in the closed state, the first biasing member causes the second valve body to be seated on the second valve seat via the first valve body. Hold. With this configuration, when the fuel pump operates to flow fuel into the first chamber and the fuel pressure in the first chamber rises above a predetermined pressure, the fuel pressure in the first chamber and the pressure between the first biasing member and the second biasing member Due to the biasing force relationship, the first valve body and the second valve body move together toward the first valve body. As a result, the second valve body moves away from the second valve seat to open the valve, thereby allowing communication between the first chamber and the second chamber. The fuel flowing into the second chamber from the first chamber is supplied to the fuel utilization device. In this way, the pressure regulating device functions as a part of the fuel supply passage and also includes the function of a check valve that has been essential in the past. Therefore, the fuel supply system does not necessarily need to have a complicated branch passage or a check valve in the fuel supply passage, which makes it compact and easier to mount.

第２の手段は、第１の手段の燃料供給システムであって、前記圧力調整装置は、前記第２弁体が前記第１弁体側への移動を規制する規制部材を備えており、前記第１室の燃料の圧力がさらに高まると、前記第１弁体がさらに開弁方向に移動する一方で前記第２弁体の移動が前記規制部材によって規制されることにより、前記第１弁体が前記第１弁座から離れて開弁し、余剰燃料が前記貫通孔と前記還流出口とを通して前記燃料タンクに還流する。 A second means is the fuel supply system of the first means, wherein the pressure regulating device includes a restricting member that restricts movement of the second valve body toward the first valve body, When the pressure of the fuel in one chamber further increases, the first valve body moves further in the valve opening direction while the movement of the second valve body is restricted by the restricting member. The valve is opened away from the first valve seat, and surplus fuel is recirculated to the fuel tank through the through hole and the recirculation outlet.

第２の手段によると、圧力調整装置は、第２弁体の第１弁体側への移動が規制部材により規制される。そのため、第１室内の燃料の圧力が所定の圧力よりさらに高くなると、第１弁体は第２弁体の第１弁座から離れて還流出口側に移動する。これにより、第１弁体は開弁状態になり第１室と還流出口との間が連通する。よって、余剰燃料が第１弁体の貫通孔を通り還流出口から燃料タンクへ還流する。 According to the second means, in the pressure regulating device, the movement of the second valve body toward the first valve body is restricted by the restricting member. Therefore, when the pressure of the fuel in the first chamber becomes higher than the predetermined pressure, the first valve body separates from the first valve seat of the second valve body and moves to the recirculation outlet side. As a result, the first valve body is opened, and the first chamber and the recirculation outlet are communicated with each other. Therefore, surplus fuel flows through the through-hole of the first valve body and flows back from the recirculation outlet to the fuel tank.

第３の手段は、第１の手段または第２の手段の燃料供給システムであって、前記燃料ポンプが停止したときは前記第１弁体及び前記第２弁体が前記第１付勢部材の付勢によって閉弁し、前記燃料供給通路の前記第２室から前記燃料利用装置側における燃料の圧力が所定の範囲内で保持される。 A third means is the fuel supply system of the first means or the second means, wherein when the fuel pump is stopped, the first valve body and the second valve body are driven by the first biasing member. The valve is closed by being energized, and the pressure of the fuel on the fuel utilization device side from the second chamber of the fuel supply passage is kept within a predetermined range.

第３の手段によると、燃料ポンプが停止することにより、第１室への燃料の流入が停止して第１室内の燃料の圧力が低下する。第１室内の燃料の圧力が所定の圧力より低くなると、第１弁体と第２弁体は第１付勢部材に押圧されて閉弁状態になる。これにより、圧力調整装置は逆止弁のように燃料利用装置側から燃料供給上流への流入を防止する。よって、燃料供給通路は第２室から燃料利用装置側において閉じられた状態となり、燃料利用装置内の燃圧を所定の圧力で保持できる。 According to the third means, stopping the fuel pump stops the flow of fuel into the first chamber and reduces the pressure of the fuel in the first chamber. When the pressure of the fuel in the first chamber becomes lower than the predetermined pressure, the first valve element and the second valve element are pressed by the first biasing member to close the valve. As a result, the pressure regulating device prevents the inflow from the fuel utilization device side to the upstream side of the fuel supply like a check valve. Therefore, the fuel supply passage is closed on the side of the fuel utilization device from the second chamber, and the fuel pressure in the fuel utilization device can be maintained at a predetermined pressure.

第４の手段は、第１の手段から第３の手段のいずれか一の燃料供給システムであって、前記第１弁体が前記第１室内の燃料から圧力を受ける受圧面積は、前記第２弁体が前記第１室内の燃料から圧力を受ける受圧面積よりも大きい。 A fourth means is the fuel supply system according to any one of the first to third means, wherein the pressure receiving area of the first valve element that receives pressure from the fuel in the first chamber is The valve body has a larger pressure receiving area than the pressure from the fuel in the first chamber.

第４の手段によると、燃料ポンプの作動時においては、第１弁体と第２弁体は、第１室内に流入した燃料から圧力を受ける。第１弁体は第２弁体よりも第１室内の燃料から圧力を受ける受圧面積が大きいため、第１室内の燃料が第１弁体を押す力は、第１室内の燃料が第２弁体を押す力より常に大きくなる。その差は第１室内の燃料の圧力が大きくなるほど拡大するため、第２付勢部材の付勢力も手伝って、第１弁体と第２弁体は一体的に開弁方向に押される。よって、圧力調整装置内に流入する燃料の圧力に応じて第２弁体を開閉できる。
According to the fourth means, when the fuel pump is in operation, the first valve body and the second valve body receive pressure from the fuel flowing into the first chamber. Since the pressure receiving area of the first valve body that receives pressure from the fuel in the first chamber is larger than that of the second valve body, the force that pushes the fuel in the first chamber against the first valve body is the same as that of the fuel in the first chamber. It is always greater than the pushing force of the body. Since the difference increases as the pressure of the fuel in the first chamber increases, the first valve body and the second valve body are integrally pushed in the valve opening direction with the help of the biasing force of the second biasing member. Therefore, the second valve body can be opened and closed according to the pressure of the fuel flowing into the pressure regulating device.

第５の手段は、第１の手段から第４の手段のいずれか一の燃料供給システムであって、前記燃料供給通路の前記圧力調整装置よりも前記燃料ポンプ側にリリーフ弁が設けられている。 A fifth means is the fuel supply system according to any one of the first to fourth means, wherein a relief valve is provided in the fuel supply passage on the fuel pump side of the pressure regulator. .

第５の手段によると、燃料供給通路の圧力調整装置よりも燃料ポンプ側にリリーフ弁が設けられている。これにより、高い燃圧に上昇した場合にリリーフ弁が開弁し、圧力が解放される。よって、燃料の圧力を配管の耐圧性能から見て過剰圧力にならない範囲に制御できる。 According to the fifth means, the relief valve is provided on the fuel pump side of the pressure regulator of the fuel supply passage. As a result, when the fuel pressure rises to a high level, the relief valve opens to release the pressure. Therefore, the pressure of the fuel can be controlled within a range that does not become an excessive pressure in view of the pressure resistance of the piping.

本明細書に開示の技術によると、圧力調整装置のために燃料供給通路に複雑な分岐通路や逆止弁を設ける必要のない、コンパクトでより搭載設計が容易となる燃料供給システムを提供することができる。 According to the technology disclosed in this specification, there is provided a compact fuel supply system that does not require complicated branch passages or check valves in the fuel supply passage for the pressure adjustment device, and that facilitates mounting design. can be done.

燃料ポンプの始動直後における実施形態にかかる燃料供給システムの構成図である。圧力調整装置の２つの弁体の位置は後述の第１状態にある。1 is a configuration diagram of a fuel supply system according to an embodiment immediately after starting a fuel pump; FIG. The positions of the two valve bodies of the pressure regulating device are in the first state described below. 燃料ポンプ作動時において燃料供給通路が連通したときにおける燃料供給システムの構成図である。圧力調整装置の２つの弁体の位置は後述の第２状態にある。FIG. 4 is a configuration diagram of the fuel supply system when the fuel supply passage is in communication when the fuel pump is in operation; The positions of the two valve bodies of the pressure regulating device are in the second state described below. 燃料ポンプ作動時において圧力調整装置によって燃料の圧力が調整されているときにおける燃料供給システムの構成図である。圧力調整装置の２つの弁体の位置は後述の第３状態にある。FIG. 4 is a configuration diagram of the fuel supply system when the fuel pressure is adjusted by the pressure adjustment device when the fuel pump is in operation; The positions of the two valve bodies of the pressure regulating device are in the third state described later. 燃料ポンプ停止時において圧力調整装置の閉弁によって下流側に残圧が保持されたときにおける燃料供給システムの構成図である。圧力調整装置は第１状態にある。FIG. 4 is a configuration diagram of the fuel supply system when the residual pressure is maintained downstream by closing the valve of the pressure regulating device when the fuel pump is stopped; The pressure regulator is in the first state. 燃料ポンプ停止時において圧力調整装置によって下流側に保持された残圧が調整されているときにおける燃料供給システムの構成図である。圧力調整装置は第２状態にある。FIG. 4 is a configuration diagram of the fuel supply system when the residual pressure held on the downstream side is adjusted by the pressure adjustment device when the fuel pump is stopped; The pressure regulator is in the second state. 燃料ポンプ再作動時の燃料供給システムの構成図である。圧力調整装置は第１状態にある。FIG. 4 is a configuration diagram of the fuel supply system when the fuel pump is restarted; The pressure regulator is in the first state. 圧力調整装置内の燃料通過流量と配管圧力との関係を示す図である。It is a figure which shows the relationship between the fuel passage flow volume in a pressure regulator, and a piping pressure.

以下、本明細書に開示の技術を実施するための実施形態について図面を用いて説明する。実施形態にかかる燃料供給システムは、自動車等の車両において、燃料タンク内の燃料を内燃機関であるエンジンに供給するものである。 Hereinafter, embodiments for implementing the technology disclosed in this specification will be described with reference to the drawings. A fuel supply system according to an embodiment supplies fuel in a fuel tank to an engine, which is an internal combustion engine, in a vehicle such as an automobile.

（燃料供給システムの概要）
図１は燃料供給システムの概要を示す構成図である。図１に示すように、燃料供給システム１は、燃料タンク２内の燃料をエンジン３（燃料利用装置）に圧送する燃料ポンプ４と、燃料ポンプ４とエンジン３とを接続する一つの燃料供給通路５と、燃料供給通路５の途中に設けられた圧力調整装置６と、燃料供給通路５の圧力調整装置６よりも燃料ポンプ４側に設けられたリリーフ弁７とを備えている。 (Overview of fuel supply system)
FIG. 1 is a configuration diagram showing an outline of a fuel supply system. As shown in FIG. 1, the fuel supply system 1 includes a fuel pump 4 for pumping fuel in a fuel tank 2 to an engine 3 (fuel utilization device), and one fuel supply passage connecting the fuel pump 4 and the engine 3. 5 , a pressure regulating device 6 provided in the middle of the fuel supply passage 5 , and a relief valve 7 provided closer to the fuel pump 4 than the pressure regulating device 6 in the fuel supply passage 5 .

燃料タンク２内には燃料ポンプ４が設置されている。燃料ポンプ４は、例えばモータ一体型の電動式の燃料ポンプである。燃料ポンプ４は、燃料タンク２内に貯留されている燃料を吸入して加圧しながら、燃料供給通路５を介してエンジン３に供給する。燃料ポンプ４によって送り出される燃料は、電子制御装置（ＥＣＵ）で燃料ポンプ４の回転速度を制御することにより流量を変えることができる。燃料供給通路５のエンジン３付近には高圧ポンプ１１が設置されている。高圧ポンプ１１は、燃料供給通路５を流れる燃料の圧力を上昇させて、エンジン３側に排出する。エンジン３のデリバリパイプ１２は、燃料供給通路５から供給された燃料を複数のインジェクタ１３に分配する。各インジェクタ１３は、エンジン３の吸気通路又は燃焼室に燃料を噴射する。 A fuel pump 4 is installed in the fuel tank 2 . The fuel pump 4 is, for example, a motor-integrated electric fuel pump. The fuel pump 4 sucks and pressurizes the fuel stored in the fuel tank 2 and supplies the fuel to the engine 3 through the fuel supply passage 5 . The flow rate of the fuel pumped by the fuel pump 4 can be changed by controlling the rotational speed of the fuel pump 4 with an electronic control unit (ECU). A high-pressure pump 11 is installed near the engine 3 in the fuel supply passage 5 . The high-pressure pump 11 increases the pressure of the fuel flowing through the fuel supply passage 5 and discharges it to the engine 3 side. A delivery pipe 12 of the engine 3 distributes fuel supplied from the fuel supply passage 5 to a plurality of injectors 13 . Each injector 13 injects fuel into an intake passage or combustion chamber of the engine 3 .

燃料供給通路５の途中には、圧力調整装置６が接続されている。以下の説明では、燃料供給通路５の圧力調整装置６より燃料ポンプ４側を上流側部分５ａ、エンジン３側を下流側部分５ｂと呼ぶ。圧力調整装置６は、燃料ポンプ４の作動時において燃料供給通路５を流れる燃料をエンジン３へ供給すると共に、供給される燃料の圧力を所定の圧力に調整する。一方、燃料ポンプ４の停止時（非作動時）において、下流側部分５ｂ内の燃料が上流側部分５ａへ流れるのを阻止すると共に、下流側部分５ｂ内の燃料の圧力を所定の圧力に調整する。 A pressure regulating device 6 is connected in the middle of the fuel supply passage 5 . In the following description, the portion of the fuel supply passage 5 closer to the fuel pump 4 than the pressure regulator 6 is referred to as an upstream portion 5a, and the portion closer to the engine 3 is referred to as a downstream portion 5b. The pressure adjustment device 6 supplies fuel flowing through the fuel supply passage 5 to the engine 3 when the fuel pump 4 is in operation, and adjusts the pressure of the supplied fuel to a predetermined pressure. On the other hand, when the fuel pump 4 is stopped (not in operation), the fuel in the downstream portion 5b is prevented from flowing to the upstream portion 5a, and the pressure of the fuel in the downstream portion 5b is adjusted to a predetermined pressure. do.

燃料供給通路５の上流側部分５ａからは、燃料タンク２内に連通する燃料排出通路５ｃが分岐されている。燃料排出通路５ｃにはリリーフ弁７が設けられている。リリーフ弁７は、通常時に閉弁しており、上流側部分５ａ内の燃料の圧力が所定の圧力よりも高くなると開弁し、上流側部分５ａを流れる燃料の一部を燃料排出通路５ｃから燃料タンク２内に排出させる。 A fuel discharge passage 5c communicating with the inside of the fuel tank 2 is branched from the upstream portion 5a of the fuel supply passage 5. As shown in FIG. A relief valve 7 is provided in the fuel discharge passage 5c. The relief valve 7 is normally closed, and opens when the pressure of the fuel in the upstream portion 5a becomes higher than a predetermined pressure. It is discharged into the fuel tank 2.

（圧力調整装置）
図１に示すように、圧力調整装置６は、略円筒状の内部空間を形成するケーシング２１を備えている。ケーシング２１は、燃料ポンプ４側から燃料が流入する主調圧室２２（第１室）と、エンジン３（燃料利用装置）側へ燃料が流出する副調圧室２３（第２室）と、主調圧室２２から余剰燃料が流出する背圧室２４を備えている。主調圧室２２には燃料供給通路５の上流側部分５ａと接続される燃料入口２５が設けられている。副調圧室２３には下流側部分５ｂと接続される供給出口２６が設けられている。背圧室２４には余剰燃料を燃料タンク２へ還流させる還流出口２７が設けられている。 (Pressure regulator)
As shown in FIG. 1, the pressure regulating device 6 has a casing 21 forming a substantially cylindrical inner space. The casing 21 includes a main pressure regulating chamber 22 (first chamber) into which fuel flows from the fuel pump 4 side, an auxiliary pressure regulating chamber 23 (second chamber) into which fuel flows out to the engine 3 (fuel utilization device) side, and a main pressure regulating chamber 23 (second chamber). A back pressure chamber 24 is provided through which surplus fuel flows out from the pressure chamber 22 . A fuel inlet 25 connected to the upstream portion 5 a of the fuel supply passage 5 is provided in the main pressure regulating chamber 22 . The sub pressure regulating chamber 23 is provided with a supply outlet 26 connected to the downstream portion 5b. The back pressure chamber 24 is provided with a recirculation outlet 27 for recirculating surplus fuel to the fuel tank 2 .

ケーシング２１内には、主調圧室２２と還流出口２７との間を連通・遮断する第１弁体３１と、主調圧室２２と副調圧室２３の間を連通・遮断する第２弁体３２と、第１弁体３１を閉弁方向に付勢する大スプリング３３（第１付勢部材）と、第２弁体３２を開弁方向に付勢する小スプリング３４（第２付勢部材）と、第２弁体３２の移動を規制する規制部材３５が配置されている。 In the casing 21, a first valve body 31 for communicating/blocking communication between the main pressure regulating chamber 22 and the return outlet 27, and a second valve body 31 for communicating/blocking communication between the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 are provided. 32, a large spring 33 (first biasing member) that biases the first valve body 31 in the valve closing direction, and a small spring 34 (second biasing member) that biases the second valve body 32 in the valve opening direction. ) and a regulating member 35 for regulating the movement of the second valve body 32 are arranged.

ケーシング２１は、主調圧室２２と副調圧室２３を形成する第１ケース部材３６と、背圧室２４を形成する第２ケース部材３７と、を結合してなる。両ケース部材３６，３７の結合部には、径方向外方へ円環状に突出するフランジ部３８が形成されている。ケーシング２１は金属製である。 The casing 21 is formed by connecting a first case member 36 forming the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 and a second case member 37 forming the back pressure chamber 24 . A flange portion 38 that protrudes radially outward in an annular shape is formed at the connecting portion between the two case members 36 and 37 . The casing 21 is made of metal.

第１ケース部材３６と第２ケース部材３７との間には、可撓性を有する円環板状のダイヤフラム３９の外周部が挟持されている。ダイヤフラム３９により、ケーシング２１の内部空間が第１ケース部材３６側の主調圧室２２と第２ケース部材３７側の背圧室２４とに区画されている。 Between the first case member 36 and the second case member 37, an outer peripheral portion of a diaphragm 39 having a flexible annular plate shape is sandwiched. The diaphragm 39 divides the internal space of the casing 21 into a main pressure regulating chamber 22 on the first case member 36 side and a back pressure chamber 24 on the second case member 37 side.

第１ケース部材３６は、フランジ部３８から軸方向に沿って延出する大径筒部３６ａと、中径筒部３６ｂと、小径筒部３６ｃと、大径筒部３６ａと中径筒部３６ｂとを接続する大径段付き部３６ｄと、大径筒部３６ａと中径筒部３６ｂとを接続する小径段付き部３６ｅと、を有する段付円筒状に形成されている。大径筒部３６ａには主調圧室２２が設けられている。大径段付き部３６ｄには、燃料入口２５が形成されている。燃料入口２５は燃料供給通路５の上流側部分５ａと接続される。小径筒部３６ｃの端部には、供給出口２６が形成されている。供給出口２６は下流側部分５ｂと接続される。 The first case member 36 includes a large-diameter tubular portion 36a extending axially from the flange portion 38, a medium-diameter tubular portion 36b, a small-diameter tubular portion 36c, a large-diameter tubular portion 36a, and a medium-diameter tubular portion 36b. and a small-diameter stepped portion 36e that connects the large-diameter cylindrical portion 36a and the medium-diameter cylindrical portion 36b. A main pressure regulating chamber 22 is provided in the large-diameter cylindrical portion 36a. A fuel inlet 25 is formed in the large-diameter stepped portion 36d. Fuel inlet 25 is connected to upstream portion 5 a of fuel supply passage 5 . A supply outlet 26 is formed at the end of the small-diameter cylindrical portion 36c. The supply outlet 26 is connected with the downstream portion 5b.

主調圧室２２内にはホルダ４０が設けられている。ホルダ４０は、軸方向に延びる円筒状の柱状部４０ａと、柱状部４０ａの一端部（後述の第２弁体３２側）から径方向外方へフランジ状に突出する弁座部４０ｂ（第２弁座）と、を有する。柱状部４０ａの他端部（弁座部４０ｂと反対側）は、第１ケース部材３６の中径筒部３６ｂの内部に圧入されている。弁座部４０ｂは、第１ケース部材３６の大径筒部３６ａの内径よりも小さい外径を有する。ホルダ４０の内部空間は副調圧室２３に区画される。 A holder 40 is provided in the main pressure regulating chamber 22 . The holder 40 includes a cylindrical columnar portion 40a extending in the axial direction, and a valve seat portion 40b (second valve seat portion 40b) protruding radially outward in a flange shape from one end portion of the columnar portion 40a (on the side of a second valve body 32, which will be described later). valve seat); The other end of the columnar portion 40a (the side opposite to the valve seat portion 40b) is press-fitted inside the medium-diameter cylindrical portion 36b of the first case member 36. As shown in FIG. The valve seat portion 40b has an outer diameter smaller than the inner diameter of the large-diameter cylindrical portion 36a of the first case member 36. As shown in FIG. The internal space of the holder 40 is partitioned into the sub pressure regulating chamber 23 .

第２ケース部材３７は、第１ケース部材３６のフランジ部３８側の開口部を閉鎖する略円筒状に形成されている。第２ケース部材３７は、軸方向においてフランジ部３８と対向する位置に還流出口２７が形成されている。還流出口２７は背圧室２４に流出した余剰燃料を燃料タンク２に還流する。 The second case member 37 is formed in a substantially cylindrical shape that closes the opening of the first case member 36 on the flange portion 38 side. The second case member 37 has a reflux outlet 27 formed at a position facing the flange portion 38 in the axial direction. The recirculation outlet 27 recirculates the surplus fuel that has flowed out to the back pressure chamber 24 to the fuel tank 2 .

ダイヤフラム３９の内周部には第１弁体３１が設けられている。第１弁体３１は、ダイヤフラム３９の背圧室２４側に配置された円環板状の挟持部材４３と結合されている。第１弁体３１と挟持部材４３とによりダイヤフラム３９が挟持されている。第１弁体３１は軸方向に貫通する貫通孔３１ａを有する。貫通孔３１ａの中央は狭くなっており、背圧室２４への燃料の流量を抑制する絞りとなっている。第１弁体３１の主調圧室２２側の開口端部には、後述する第２弁体３２の弁座部３２ｃ（第１弁座）に対して着座及び離座可能な弁部３１ｂが形成されている。第１弁体３１は、主調圧室２２と背圧室２４及び還流出口２７との間を連通・遮断する構成となっている。 A first valve body 31 is provided on the inner peripheral portion of the diaphragm 39 . The first valve body 31 is coupled to an annular plate-shaped clamping member 43 arranged on the back pressure chamber 24 side of the diaphragm 39 . A diaphragm 39 is held between the first valve body 31 and the holding member 43 . The first valve body 31 has a through-hole 31a extending therethrough in the axial direction. The center of the through-hole 31a is narrowed and serves as a throttle that suppresses the flow rate of fuel to the back pressure chamber 24. As shown in FIG. A valve portion 31b that can be seated and separated from a valve seat portion 32c (first valve seat) of the second valve body 32, which will be described later, is formed at the opening end of the first valve body 31 on the side of the main pressure regulating chamber 22. It is The first valve body 31 is configured to communicate/block communication between the main pressure regulating chamber 22 , the back pressure chamber 24 , and the recirculation outlet 27 .

ホルダ４０の弁座部４０ｂと第１弁体３１の間には第２弁体３２が配置されている。第２弁体３２は、円板状の弁板部３２ａと、弁板部３２ａの外周部にホルダ４０側に延出して形成された円環状の弁部３２ｂと、弁板部３２ａの中央部に形成された球状の弁座部３２ｃ（第１弁座）と、を有する。弁部３２ｂは、ホルダ４０の弁座部４０ｂ（第２弁座）に対して着座及び離座可能である。第２弁体３２は、主調圧室２２と副調圧室２３の間を連通・遮断する構成となっている。 A second valve body 32 is arranged between the valve seat portion 40 b of the holder 40 and the first valve body 31 . The second valve body 32 includes a disk-shaped valve plate portion 32a, an annular valve portion 32b formed on the outer peripheral portion of the valve plate portion 32a so as to extend toward the holder 40, and a central portion of the valve plate portion 32a. and a spherical valve seat portion 32c (first valve seat). The valve portion 32 b can be seated on and separated from the valve seat portion 40 b (second valve seat) of the holder 40 . The second valve body 32 is configured to communicate/block communication between the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 .

弁座部４０ｂには、第２弁体３２を覆うキャップ状の規制部材３５が装着されている。規制部材３５の中央部には第１開口孔３５ａが形成されている。規制部材３５の第１開口孔３５ａから第２弁体３２の弁座部３２ｃが露出されている。規制部材３５と弁座部４０ｂとにより第２弁体３２の軸方向の移動量が所定量に規制される。規制部材３５の第１開口孔３５ａの周囲には、複数個の第２開口孔３５ｂが形成されている。 A cap-shaped restricting member 35 that covers the second valve body 32 is attached to the valve seat portion 40b. A first opening hole 35 a is formed in the central portion of the restricting member 35 . The valve seat portion 32c of the second valve body 32 is exposed through the first opening hole 35a of the regulating member 35. As shown in FIG. The amount of movement of the second valve body 32 in the axial direction is restricted to a predetermined amount by the restricting member 35 and the valve seat portion 40b. A plurality of second openings 35b are formed around the first opening 35a of the regulating member 35. As shown in FIG.

背圧室２４内には、コイルスプリングからなる大スプリング３３（第１付勢部材）が配置されている。大スプリング３３は、第２ケース部材３７と挟持部材４３との対向面間に介装されている。大スプリング３３は、第１弁体３１を閉弁方向に付勢する。大スプリング３３は、第１弁体３１を閉弁状態すなわち弁部３１ｂが第２弁体３２の弁座部３２ｃに着座するとともに、第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂに着座する状態に保持する。 A large spring 33 (first biasing member) made of a coil spring is arranged in the back pressure chamber 24 . The large spring 33 is interposed between the facing surfaces of the second case member 37 and the holding member 43 . The large spring 33 biases the first valve body 31 in the valve closing direction. The large spring 33 closes the first valve body 31 , that is, the valve portion 31 b is seated on the valve seat portion 32 c of the second valve body 32 , and the valve portion 32 b of the second valve body 32 is seated on the valve seat portion of the holder 40 . 40b is kept seated.

第２弁体３２は、弁座部３２ｃが球面状に形成されることにより調心機能を有している。開弁時に第２弁体３２の軸がホルダ４０の弁座部４０ｂに対してずれたとしても、第１弁体３１の弁部３１ｂの円錐面が第２弁体３２の弁座部３２ｃに着座することにより、軸のずれが修正される。 The second valve body 32 has an alignment function by forming the valve seat portion 32c into a spherical shape. Even if the axis of the second valve body 32 is displaced from the valve seat portion 40b of the holder 40 when the valve is opened, the conical surface of the valve portion 31b of the first valve body 31 is aligned with the valve seat portion 32c of the second valve body 32. Seating corrects for axial misalignment.

第１ケース部材３６の大径筒部３６ａ内には、燃料入口２５から主調圧室２２に流入する燃料をろ過する主フィルタ４１が配置されている。第１ケース部材３６の中径筒部３６ｂ内には、供給出口２６から副調圧室２３に流入する燃料をろ過する副フィルタ４２が配置されている。 A main filter 41 for filtering fuel flowing into the main pressure regulating chamber 22 from the fuel inlet 25 is arranged in the large-diameter cylindrical portion 36 a of the first case member 36 . A sub-filter 42 for filtering fuel flowing into the sub-pressure regulating chamber 23 from the supply outlet 26 is arranged inside the medium-diameter cylindrical portion 36 b of the first case member 36 .

ホルダ４０の副調圧室２３内には、コイルスプリングからなる小スプリング３４（第２付勢部材）が配置されている。小スプリング３４は、副フィルタ４２と第２弁体３２の弁板部３２ａとの間に介在されている。小スプリング３４は、第２弁体３２を開弁方向に付勢しつつ副フィルタ４２に押圧している。小スプリング３４の付勢力Ｗ２は、大スプリング３３の付勢力Ｗ１よりも小さい。 A small spring 34 (second biasing member) made of a coil spring is arranged in the sub pressure regulating chamber 23 of the holder 40 . The small spring 34 is interposed between the sub-filter 42 and the valve plate portion 32 a of the second valve body 32 . The small spring 34 presses the secondary filter 42 while urging the second valve body 32 in the valve opening direction. The biasing force W2 of the small spring 34 is smaller than the biasing force W1 of the large spring 33.

第１弁体３１と第２弁体３２は、スプリングと燃料の圧力との力関係にに基づいて所望の開弁圧でもって後述の開閉動作を実現できるよう、適切な受圧面積が設定されている。なお、受圧面積とは、当業者であれば理解できるように、燃料の圧力によって各弁体を開弁方向または閉弁方向（軸方向）に移動させる力に寄与する面積である。ここでは第１弁体３１が主調圧室２２内の燃料から圧力を受ける受圧面積を「第１受圧面積Ａ１」、第２弁体３２が副調圧室２３内の燃料から圧力を受ける受圧面積を「第２受圧面積Ａ２」、第２弁体３２が主調圧室２２内の燃料から圧力を受ける受圧面積を「第３受圧面積Ａ３」と呼ぶ。 Appropriate pressure-receiving areas are set for the first valve body 31 and the second valve body 32 so that opening and closing operations, which will be described later, can be realized with a desired valve opening pressure based on the force relationship between the spring and the pressure of the fuel. there is As can be understood by those skilled in the art, the pressure-receiving area is an area that contributes to the force of moving each valve element in the valve-opening direction or the valve-closing direction (axial direction) due to the pressure of the fuel. Here, the pressure receiving area where the first valve body 31 receives pressure from the fuel in the main pressure regulating chamber 22 is "first pressure receiving area A1", and the pressure receiving area where the second valve body 32 receives pressure from the fuel in the sub pressure regulating chamber 23. is called a "second pressure receiving area A2", and the pressure receiving area where the second valve body 32 receives pressure from the fuel in the main pressure regulating chamber 22 is called a "third pressure receiving area A3".

第１受圧面積Ａ１は、第３受圧面積Ａ３より大きい。すなわち第１受圧面積Ａ１と第３受圧面積Ａ３は、主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１の方が第２弁体３２を押す力Ｆ３よりも大きくなるように設定されている（図１参照）。燃料ポンプ４の作動時には、第１弁体３１と第２弁体３２は、主調圧室２２内に流入した燃料の圧力Ｐ１を受ける。このとき第２弁体３２が開弁する条件は、小スプリング３４の付勢力Ｗ２が、主調圧室２２の燃料が第２弁体を押す力Ｆ３（＝Ｐ１×Ａ３）と第１弁体が第２弁体を押す力Ｗ１－Ｐ１×Ａ１との合計を上回ることであり、Ｗ２＞Ｐ１×Ａ３＋Ｗ１－Ｐ１×Ａ１と表される。第１弁体３１が開弁する条件は、主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１（＝Ｐ１×Ａ１）が第１弁体３１にかかる大スプリング３３の付勢力Ｗ１を上回ることであり、Ｐ１×Ａ１＞Ｗ１と表される（図２，３参照）。 The first pressure receiving area A1 is larger than the third pressure receiving area A3. That is, the first pressure-receiving area A1 and the third pressure-receiving area A3 are set so that the force F1 of the fuel in the main pressure regulating chamber 22 pushing the first valve body 31 is greater than the force F3 pushing the second valve body 32. (See Figure 1). During operation of the fuel pump 4 , the first valve body 31 and the second valve body 32 receive pressure P 1 of fuel flowing into the main pressure regulating chamber 22 . At this time, the conditions for the second valve body 32 to open are that the biasing force W2 of the small spring 34, the force F3 (=P1×A3) of the fuel in the main pressure regulating chamber 22 pushing the second valve body, and the first valve body It exceeds the sum of the force W1−P1×A1 that pushes the second valve body, and is expressed as W2>P1×A3+W1−P1×A1. The condition for opening the first valve body 31 is that the force F1 (=P1×A1) of the fuel in the main pressure regulating chamber 22 pushing the first valve body 31 is applied to the first valve body 31 by the biasing force W1 of the large spring 33 and is expressed as P1×A1>W1 (see FIGS. 2 and 3).

燃料ポンプ４の作動を停止すると、主調圧室２２内の燃料の圧力Ｐ１が燃料ポンプ４を通して抜けるため、燃料タンク２のタンク内圧（Ｐ１＝０）まで低下する。これに伴い第１弁体３１を押す力Ｆ１が低下し、大スプリング３３の付勢力Ｗ１を下回り、Ｐ１×Ａ１＜Ｗ１の力関係となる。第１弁体３１と第２弁体３２が閉弁状態であるとき、第２弁体３２は副調圧室２３内の燃料の圧力Ｐ２を受ける。このときは副調圧室２３内の燃料が第２弁体３２を押す力Ｆ２（＝Ｐ２×Ａ２）と小スプリング３４の付勢力Ｗ２の合計が大スプリング３３の付勢力Ｗ１を下回り、Ｐ２×Ａ２＋Ｗ２＜Ｗ１の力関係となる（図４参照）。 When the operation of the fuel pump 4 is stopped, the pressure P1 of the fuel in the main pressure regulating chamber 22 is released through the fuel pump 4, so the tank internal pressure of the fuel tank 2 (P1=0) is reduced. As a result, the force F1 that presses the first valve body 31 is reduced and falls below the biasing force W1 of the large spring 33, resulting in a force relationship of P1×A1<W1. When the first valve body 31 and the second valve body 32 are in the closed state, the second valve body 32 receives the fuel pressure P2 in the sub pressure regulating chamber 23 . At this time, the sum of the force F2 (=P2×A2) of the fuel in the auxiliary pressure regulating chamber 23 pushing the second valve body 32 and the biasing force W2 of the small spring 34 is less than the biasing force W1 of the large spring 33, and P2× The force relationship is A2+W2<W1 (see FIG. 4).

燃料ポンプ４の停止後、エンジン３や高圧ポンプ１１からの受熱による燃料の温度上昇により燃料供給通路５の下流側部分５ｂ及び副調圧室２３の燃料の圧力（残圧）Ｐ２が高くなる場合がある。この状態で第２弁体３２が開弁する条件は、副調圧室２３内の燃料が第２弁体３２を押す力Ｆ２と小スプリング３４の付勢力Ｗ２の合計が大スプリング３３の付勢力Ｗ１を上回ることであり、Ｐ２×Ａ２＋Ｗ２＞Ｗ１と表される（図５参照）。 When the fuel pressure (residual pressure) P2 in the downstream side portion 5b of the fuel supply passage 5 and the auxiliary pressure regulating chamber 23 increases due to an increase in fuel temperature due to heat received from the engine 3 or the high-pressure pump 11 after the fuel pump 4 is stopped. There is The condition for the second valve body 32 to open in this state is that the sum of the force F2 of the fuel in the sub pressure regulating chamber 23 pushing the second valve body 32 and the biasing force W2 of the small spring 34 is the biasing force of the large spring 33. It exceeds W1, and is expressed as P2×A2+W2>W1 (see FIG. 5).

圧力調整装置６の下流側に残圧Ｐ２が保持された状態で燃料ポンプ４を再び作動（エンジン３を高温で再始動）するときは、残圧が解放されている場合よりも燃料ポンプ４を高い回転速度で作動させる。これにより、開弁直後に圧力調整装置６内を通過する燃料の流量が多くなり、下流側に保持されていた高い残圧を維持したまま燃料を供給することができる。このように残圧Ｐ２が保持された状態で第２弁体が開弁する条件は、前述した燃料ポンプ４の作動時における条件式に、副調圧室２３内の燃料が第２弁体３２を押す力Ｆ２（＝Ｐ２×Ａ２）を加えた条件式であり、Ｐ１×Ａ１＋Ｐ２×Ａ２＋Ｗ２＞Ｗ１＋Ｐ１×Ａ３と表される（図６参照）。第２弁体が開弁すると副調圧室２３内の燃料の圧力Ｐ２はすぐに主調圧室２２内の燃料の圧力Ｐ１と同じになるため、第１弁体が開弁する条件は前述の通常のエンジン始動時と同じ式Ｐ１×Ａ１＞Ｗ１で表される。 When operating the fuel pump 4 again (restarting the engine 3 at a high temperature) while the residual pressure P2 is maintained on the downstream side of the pressure regulating device 6, the fuel pump 4 is operated more than when the residual pressure is released. Operate at high rotational speeds. As a result, the flow rate of fuel passing through the pressure regulating device 6 increases immediately after the valve is opened, and the fuel can be supplied while maintaining the high residual pressure held downstream. The condition for the second valve body to open while the residual pressure P2 is maintained is that the fuel in the auxiliary pressure regulating chamber 23 is the second valve body 32 is a conditional expression to which a force F2 (=P2*A2) for pushing is added, and is expressed as P1*A1+P2*A2+W2>W1+P1*A3 (see FIG. 6). When the second valve body opens, the fuel pressure P2 in the sub pressure regulating chamber 23 immediately becomes the same as the fuel pressure P1 in the main pressure regulating chamber 22. Therefore, the condition for opening the first valve body is as described above. It is represented by the same formula P1×A1>W1 as when the engine is started normally.

（燃料供給システム１及び圧力調整装置６の作用）
燃料供給システム１では、燃料供給通路５を通じてエンジン３に燃料が供給されるとともに、燃料供給通路５上の圧力調整装置６により燃料の圧力が調整される。圧力調整装置６は、通常時は、図１に示すように、大スプリング３３により、第１弁体３１の弁部３１ｂが第２弁体３２の弁座部３２ｃに着座すると共に、第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂに着座する状態に保持されている。この状態すなわち第１弁体３１及び第２弁体３２が共に閉弁した状態を「第１状態」という。 (Actions of fuel supply system 1 and pressure regulator 6)
In the fuel supply system 1 , fuel is supplied to the engine 3 through the fuel supply passage 5 and the pressure of the fuel is adjusted by the pressure regulator 6 on the fuel supply passage 5 . In the pressure regulating device 6, as shown in FIG. 1, the valve portion 31b of the first valve body 31 is seated on the valve seat portion 32c of the second valve body 32 by the large spring 33, and the second valve The valve portion 32 b of the body 32 is held in a state of being seated on the valve seat portion 40 b of the holder 40 . This state, ie, the state in which both the first valve body 31 and the second valve body 32 are closed, is referred to as a "first state."

（燃料ポンプ４の作動時）
圧力調整装置６の第１状態（図１参照）において、燃料ポンプ４の作動により燃料供給通路５の上流側部分５ａに送出された燃料は、圧力調整装置６の燃料入口２５を通じて主調圧室２２に流入する。 (When fuel pump 4 is operating)
In the first state (see FIG. 1) of the pressure regulating device 6, the fuel delivered to the upstream portion 5a of the fuel supply passage 5 by the operation of the fuel pump 4 flows through the fuel inlet 25 of the pressure regulating device 6 into the main pressure regulating chamber 22. flow into

主調圧室２２の燃料の圧力Ｐ１が上昇して、主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１が大スプリング３３の付勢力Ｗ１を上回ると、第１弁体３１が背圧室２４側すなわち開弁方向に押圧される。これにともない、小スプリング３４の付勢力Ｗ２によって第２弁体３２が第１弁体３１と共に背圧室２４側すなわち開弁方向に移動する。これにより、第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂから離座し、弁板部３２ａが規制部材３５に当接する（図２参照）。この状態すなわち第１弁体３１が閉弁したまま第２弁体３２が開弁する状態を「第２状態」という。第２状態では、主調圧室２２と副調圧室２３とが規制部材３５の第１開口孔３５ａと第２開口孔３５ｂを介して連通する。主調圧室２２内の燃料は副調圧室２３に流入し、供給出口２６、燃料供給通路５の下流側部分５ｂを通じてエンジン３に供給される。 When the pressure P1 of the fuel in the main pressure regulating chamber 22 rises and the force F1 of the fuel in the main pressure regulating chamber 22 pushing the first valve body 31 exceeds the biasing force W1 of the large spring 33, the first valve body 31 is pushed back. It is pushed toward the pressure chamber 24 side, that is, in the valve opening direction. Accordingly, the biasing force W2 of the small spring 34 causes the second valve body 32 and the first valve body 31 to move toward the back pressure chamber 24, that is, in the valve opening direction. As a result, the valve portion 32b of the second valve body 32 is separated from the valve seat portion 40b of the holder 40, and the valve plate portion 32a comes into contact with the regulating member 35 (see FIG. 2). This state, that is, the state in which the second valve body 32 opens while the first valve body 31 remains closed, is referred to as a "second state." In the second state, the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 communicate with each other through the first opening 35a and the second opening 35b of the regulating member 35 . Fuel in the main pressure regulating chamber 22 flows into the sub pressure regulating chamber 23 and is supplied to the engine 3 through the supply outlet 26 and the downstream portion 5 b of the fuel supply passage 5 .

さらに、大スプリング３３の付勢に抗して、第１弁体３１が背圧室２４側に向かって押圧されると第１弁体３１の弁部３１ｂが第２弁体３２の弁座部３２ｃから離座する（図３参照）。この状態すなわち第１弁体３１及び第２弁体３２が共に開弁する状態を「第３状態」という。第３状態では、主調圧室２２の燃料の一部が、余剰燃料として第１弁体３１の貫通孔３１ａを通じて背圧室２４に流出し、還流出口２７から排出される。 Furthermore, when the first valve body 31 is pushed toward the back pressure chamber 24 side against the urging force of the large spring 33, the valve portion 31b of the first valve body 31 moves to the valve seat portion of the second valve body 32. 32c (see FIG. 3). This state, ie, the state in which both the first valve body 31 and the second valve body 32 are open, is referred to as a "third state." In the third state, part of the fuel in the main pressure regulating chamber 22 flows into the back pressure chamber 24 through the through hole 31 a of the first valve body 31 as surplus fuel and is discharged from the recirculation outlet 27 .

燃料ポンプ４が低圧運転の状態、すなわち圧力調整装置６内の燃料の通過流量Ｖが図７に示すＶａからＶｂの範囲であるときは、第１弁体３１の貫通孔３１ａの絞りによって通過流量Ｖが抑制されることなく、圧力調整される。 When the fuel pump 4 is in a low pressure operation state, that is, when the flow rate V of the fuel in the pressure regulator 6 is in the range of Va to Vb shown in FIG. The pressure is regulated without V being suppressed.

主調圧室２２内の燃料の圧力Ｐ１が低下すると、主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１が低下し、大スプリング３３の付勢により第１弁体３１は閉弁方向に移動する。圧力Ｐ１が大スプリング３３の付勢力Ｗ１を下回ると、第１弁体３１の弁部３１ｂが第２弁体３２の弁座部３２ｃに着座し、第２状態となる（図２参照）。 When the pressure P1 of the fuel in the main pressure regulating chamber 22 decreases, the force F1 of the fuel in the main pressure regulating chamber 22 pushing the first valve body 31 decreases, and the first valve body 31 closes due to the force of the large spring 33. move in the direction When the pressure P1 falls below the biasing force W1 of the large spring 33, the valve portion 31b of the first valve body 31 is seated on the valve seat portion 32c of the second valve body 32 to enter the second state (see FIG. 2).

（燃料ポンプ４の停止時）
燃料ポンプ４を停止すると、主調圧室２２内の燃料の圧力Ｐ１が低下するため、第１弁体３１は上述の通り大スプリング３３の付勢により閉弁する。また副調圧室２３内の燃料の圧力Ｐ１も低下するため、副調圧室２３内の燃料が第２弁体３２を押す力Ｆ２が低下し、大スプリング３３の付勢により第２弁体３２は閉弁方向に移動する。最終的には第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂに着座し、第１状態となる（図４参照）。一方で、主調圧室２２内の燃料の圧力は燃料ポンプ４を通して抜け、タンク内圧まで低下する。 (When fuel pump 4 is stopped)
When the fuel pump 4 is stopped, the pressure P1 of the fuel in the main pressure regulating chamber 22 decreases, so that the first valve body 31 is closed by the force of the large spring 33 as described above. In addition, since the pressure P1 of the fuel in the sub pressure regulating chamber 23 also decreases, the force F2 of the fuel in the sub pressure regulating chamber 23 pushing the second valve element 32 decreases, and the large spring 33 biases the second valve element. 32 moves in the valve closing direction. Finally, the valve portion 32b of the second valve body 32 is seated on the valve seat portion 40b of the holder 40, resulting in the first state (see FIG. 4). On the other hand, the pressure of the fuel in the main pressure regulating chamber 22 is released through the fuel pump 4 and is reduced to the tank internal pressure.

燃料ポンプ４の停止時には、上述のように圧力調整装置６の両弁体３１，３２が閉弁するだけでなく、各インジェクタ１３も閉弁するため、燃料供給通路５の下流側部分５ｂにおいて燃料の残圧Ｐ２が保持される。この状態において、例えば、エンジン３や高圧ポンプ１１が発する熱の影響によって、下流側部分５ｂ内の燃料の圧力が再び高くなる場合がある。下流側部分５ｂ内の燃料の圧力が高くなるにともない、副調圧室２３の燃料の圧力Ｐ２も高くなる。 When the fuel pump 4 is stopped, not only the valve bodies 31 and 32 of the pressure regulating device 6 are closed as described above, but also the injectors 13 are closed. of residual pressure P2 is held. In this state, for example, due to the influence of heat generated by the engine 3 or the high-pressure pump 11, the pressure of the fuel in the downstream portion 5b may rise again. As the pressure of fuel in the downstream portion 5b increases, the pressure P2 of fuel in the sub pressure regulating chamber 23 also increases.

副調圧室２３の燃料の圧力Ｐ２が上昇し、副調圧室２３の燃料が第２弁体３２を押す力Ｆ２と小スプリング３４の付勢力Ｗ２の合計が大スプリング３３の付勢力Ｗ１を上回ると、大スプリング３３の付勢に抗して、第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂから離座し、第２状態となる（図５参照）。この状態では、副調圧室２３の燃料が、余剰燃料として規制部材３５の第２開口孔３５ｂを介して主調圧室２２に流出した後、燃料入口２５から燃料供給通路５の上流側部分５ａへ排出される。その燃料は、停止している燃料ポンプ４を逆流して燃料タンク２内へ排出される。 The fuel pressure P2 in the sub pressure regulating chamber 23 rises, and the sum of the force F2 with which the fuel in the sub pressure regulating chamber 23 presses the second valve body 32 and the biasing force W2 of the small spring 34 exceeds the biasing force W1 of the large spring 33. When it exceeds, the valve portion 32b of the second valve body 32 is separated from the valve seat portion 40b of the holder 40 against the urging force of the large spring 33 to enter the second state (see FIG. 5). In this state, the fuel in the sub pressure regulating chamber 23 flows out as surplus fuel into the main pressure regulating chamber 22 through the second opening 35b of the regulating member 35, and then flows through the upstream portion 5a of the fuel supply passage 5 from the fuel inlet 25. is discharged to The fuel flows back through the stopped fuel pump 4 and is discharged into the fuel tank 2 .

副調圧室２３の燃料の圧力Ｐ２が低下し、副調圧室２３の燃料が第２弁体３２を押す力Ｆ２と小スプリング３４の付勢力Ｗ２の合計が大スプリング３３の付勢力Ｗ１を下回ると、大スプリング３３の付勢によって、第２弁体３２の弁部３２ｂがホルダ４０の弁座部４０ｂに着座し、第１状態となる（図４参照）。 The pressure P2 of the fuel in the sub pressure regulating chamber 23 decreases, and the sum of the force F2 with which the fuel in the sub pressure regulating chamber 23 presses the second valve body 32 and the biasing force W2 of the small spring 34 exceeds the biasing force W1 of the large spring 33. When it falls below, the valve portion 32b of the second valve body 32 is seated on the valve seat portion 40b of the holder 40 by the urging force of the large spring 33, thereby entering the first state (see FIG. 4).

（燃料ポンプ４の再作動時）
圧力調整装置６の下流側に残圧が保持された状態でエンジン３を再始動する場合、燃料ポンプ４を通常の始動よりも高い回転速度で作動させる（図６参照）。これにより、開弁後に圧力調整装置６内を通過する燃料の流量が多くなり、圧力が高い状態で燃料を供給することができる。主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１が大スプリング３３の付勢力Ｗ１を上回ると、第１弁体３１は大スプリング３３の付勢に抗して背圧室２４側すなわち開弁方向に向かって押圧される。第２弁体３２は、副調圧室２３内に保持された燃料の残圧Ｐ２を受けており、第１弁体３１が開弁方向に押圧されるにともない、この残圧Ｐ２によるＦ２及び小スプリング３４の付勢力Ｗ２によって、開弁方向に移動する。これにより、第１弁体３１と第２弁体３２は第２状態になり、主調圧室２２と副調圧室２３が連通する。さらに第１弁体３１が開弁方向に向かって押圧されると、第３状態になる。 (When reactivating the fuel pump 4)
When the engine 3 is restarted with residual pressure maintained downstream of the pressure regulating device 6, the fuel pump 4 is operated at a higher rotation speed than during normal startup (see FIG. 6). As a result, the flow rate of fuel passing through the pressure regulating device 6 increases after the valve is opened, and the fuel can be supplied in a high pressure state. When the force F1 of the fuel in the main pressure regulating chamber 22 pushing the first valve body 31 exceeds the urging force W1 of the large spring 33, the first valve body 31 resists the urging force of the large spring 33 and pushes toward the back pressure chamber 24 side. That is, it is pressed in the valve opening direction. The second valve body 32 receives the residual pressure P2 of the fuel held in the sub pressure regulating chamber 23, and as the first valve body 31 is pushed in the valve opening direction, F2 and F2 due to this residual pressure P2 By the biasing force W2 of the small spring 34, it moves in the valve opening direction. As a result, the first valve body 31 and the second valve body 32 enter the second state, and the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 communicate with each other. Further, when the first valve body 31 is pressed toward the valve opening direction, the third state is entered.

燃料ポンプ４から圧力調整装置６へ送られる燃料の通過流量Ｖが多くなると、余剰燃料が第１弁体３１の貫通孔３１ａを介して背圧室２４に流出する（図３参照）。通過流量Ｖが図７に示すＶｂを超えて増加すると第１弁体３１の貫通孔３１ａの絞りにより背圧室２４への流量が抑制される。さらに通過流量Ｖが増加してＶｃに達し、背圧室２４へ流出する燃料の圧力が所定の圧力まで上昇すると、リリーフ弁７が開弁する。燃料供給通路５の上流側部分５ａの燃料は、燃料排出通路５ｃから燃料タンク２内へ排出される。これにより、燃料の圧力が過剰圧力にならないよう制御される。 When the flow rate V of the fuel sent from the fuel pump 4 to the pressure regulating device 6 increases, surplus fuel flows out to the back pressure chamber 24 through the through hole 31a of the first valve body 31 (see FIG. 3). When the passing flow rate V increases beyond Vb shown in FIG. When the flow rate V further increases and reaches Vc, and the pressure of the fuel flowing out to the back pressure chamber 24 rises to a predetermined pressure, the relief valve 7 opens. The fuel in the upstream portion 5a of the fuel supply passage 5 is discharged into the fuel tank 2 through the fuel discharge passage 5c. This controls the pressure of the fuel so that it does not become an excessive pressure.

（実施形態による利点）
上記実施形態に係る燃料供給システム１は、一つの燃料供給通路５上に圧力調整装置６が配置されている。圧力調整装置６には第１弁体３１と第２弁体３２が備えられている。第１弁体３１は大スプリング３３（第１付勢部材）によって閉弁方向に付勢され、第２弁体３２は小スプリング３４（第２付勢部材）により開弁方向に付勢される。第１弁体３１と第２弁体３２が閉弁状態であるときは、大スプリング３３が第１弁体３１を介して第２弁体３２をホルダ４０の弁座部４０ｂ（第２弁座）に着座した状態に保持する。 (Advantages of Embodiment)
In the fuel supply system 1 according to the above embodiment, a pressure regulator 6 is arranged on one fuel supply passage 5 . The pressure regulating device 6 is provided with a first valve body 31 and a second valve body 32 . The first valve body 31 is biased in the valve closing direction by a large spring 33 (first biasing member), and the second valve body 32 is biased in the valve opening direction by a small spring 34 (second biasing member). . When the first valve body 31 and the second valve body 32 are in the closed state, the large spring 33 moves the second valve body 32 through the first valve body 31 to the valve seat portion 40b (the second valve seat) of the holder 40. ) in a seated position.

この構成により、燃料ポンプ４が作動して燃料が主調圧室２２（第１室）に流入し、主調圧室２２内の燃料の圧力が所定の圧力より高くなると、主調圧室２２内の燃料の圧力、大スプリング３３と小スプリング３４の付勢力の関係によって、第１弁体３１と第２弁体３２が一体となって第１弁体３１側に移動する。これにより、第２弁体３２はホルダ４０の弁座部４０ｂから離れて開弁状態になり主調圧室２２と副調圧室２３（第２室）とを通る燃料供給通路５が連通する。主調圧室２２から副調圧室２３に流入した燃料は供給出口２６からエンジン３（燃料利用装置）に供給される。このように圧力調整装置６は燃料供給通路５の一部として機能するとともに、従来必須であった逆止弁の機能をも内包する。そのため、燃料供給システム１は燃料供給通路５に複雑な分岐通路や逆止弁を必ずしも設ける必要がなく、コンパクトでより搭載設計が容易となる。 With this configuration, when the fuel pump 4 operates and fuel flows into the main pressure regulating chamber 22 (first chamber), and the pressure of the fuel in the main pressure regulating chamber 22 becomes higher than a predetermined pressure, the fuel in the main pressure regulating chamber 22 , and the biasing force of the large spring 33 and the small spring 34, the first valve body 31 and the second valve body 32 move together toward the first valve body 31 side. As a result, the second valve body 32 moves away from the valve seat portion 40b of the holder 40 to open the valve, thereby communicating the fuel supply passage 5 passing through the main pressure regulating chamber 22 and the sub pressure regulating chamber 23 (second chamber). The fuel flowing from the main pressure regulating chamber 22 into the sub pressure regulating chamber 23 is supplied from the supply outlet 26 to the engine 3 (fuel utilization device). In this manner, the pressure regulating device 6 functions as a part of the fuel supply passage 5 and also includes the function of a check valve, which has been essential in the past. Therefore, the fuel supply system 1 does not necessarily need to be provided with a complicated branch passage or a check valve in the fuel supply passage 5, and is compact and easy to mount.

圧力調整装置６は、第２弁体３２の第１弁体３１側への移動が規制部材３５により規制される。そのため、主調圧室２２内の燃圧が所定の圧力よりさらに高くなると、第１弁体３１は第２弁体３２の弁座部３２ｃ（第１弁座）から離れて還流出口２７側に移動する。これにより、第１弁体３１は開弁状態になり主調圧室２２と還流出口２７との間が連通する。主調圧室２２内の余剰燃料は、第１弁体３１の貫通孔３１ａを通り還流出口２７から燃料タンクへ還流する。 In the pressure regulating device 6 , movement of the second valve body 32 toward the first valve body 31 is restricted by the restriction member 35 . Therefore, when the fuel pressure in the main pressure regulating chamber 22 becomes higher than the predetermined pressure, the first valve body 31 separates from the valve seat portion 32c (first valve seat) of the second valve body 32 and moves toward the recirculation outlet 27 side. . As a result, the first valve body 31 is opened, and the main pressure regulating chamber 22 and the recirculation outlet 27 are communicated with each other. Excess fuel in the main pressure regulating chamber 22 passes through the through hole 31a of the first valve body 31 and flows back from the recirculation outlet 27 to the fuel tank.

燃料ポンプ４が停止することにより、主調圧室２２への燃料の流入が停止して主調圧室２２内の燃料の圧力Ｐ１が低下する。主調圧室２２内の燃料の圧力Ｐ１が所定の圧力より低くなると、第１弁体３１と第２弁体３２は大スプリング３３に押圧されて閉弁状態になる。これにより、圧力調整装置６は逆止弁のようにエンジン３側から燃料供給通路５の上流側部分５ａへの流入を防止する。よって、燃料供給通路５は副調圧室２３からエンジン３側において閉じられた状態となり、エンジン３内の燃圧を所定の圧力で保持できる。 By stopping the fuel pump 4, the inflow of fuel into the main pressure regulating chamber 22 is stopped and the pressure P1 of the fuel in the main pressure regulating chamber 22 decreases. When the fuel pressure P1 in the main pressure regulating chamber 22 becomes lower than a predetermined pressure, the first valve body 31 and the second valve body 32 are pressed by the large spring 33 to close the valves. As a result, the pressure regulating device 6 prevents the inflow of fuel from the engine 3 side to the upstream portion 5a of the fuel supply passage 5 like a check valve. Therefore, the fuel supply passage 5 is closed from the auxiliary pressure regulating chamber 23 to the engine 3 side, and the fuel pressure in the engine 3 can be maintained at a predetermined pressure.

燃料ポンプ４の作動時においては、第１弁体３１と第２弁体３２は、主調圧室２２内に流入した燃料から圧力を受ける。第１弁体３１が主調圧室２２内の燃料から圧力を受ける第１受圧面積Ａ１は、第２弁体３２が主調圧室２２内の燃料から圧力を受ける第３受圧面積Ａ３よりも大きい。そのため、主調圧室２２内の燃料が第１弁体３１を押す力Ｆ１は、主調圧室２２内の燃料が第２弁体３２を押す力Ｆ３より常に大きくなる。その差Ｆ１－Ｆ３は主調圧室２２内の燃料の圧力が大きくなるほど拡大するため、小スプリング３４の付勢力Ｗ２も手伝って、第１弁体３１と第２弁体３２は一体的に開弁方向に押される。よって、圧力調整装置６内に流入する燃料の圧力に応じて第２弁体３２を開閉できる。 During operation of the fuel pump 4 , the first valve body 31 and the second valve body 32 receive pressure from the fuel flowing into the main pressure regulating chamber 22 . A first pressure receiving area A1 where the first valve body 31 receives pressure from the fuel in the main pressure regulating chamber 22 is larger than a third pressure receiving area A3 where the second valve body 32 receives pressure from the fuel in the main pressure regulating chamber 22 . Therefore, the force F1 with which the fuel in the main pressure regulating chamber 22 pushes the first valve body 31 is always greater than the force F3 with which the fuel in the main pressure regulating chamber 22 pushes the second valve body 32 . Since the difference F1-F3 increases as the pressure of the fuel in the main pressure regulating chamber 22 increases, the biasing force W2 of the small spring 34 also helps the first valve body 31 and the second valve body 32 to integrally open. pushed in the direction Therefore, the second valve body 32 can be opened and closed according to the pressure of the fuel flowing into the pressure regulating device 6 .

燃料供給通路５の圧力調整装置６よりも燃料ポンプ４側にリリーフ弁７が設けられている。これにより、高い燃圧に上昇した場合にリリーフ弁７が開弁し、圧力が解放される。よって、燃料の圧力を配管の耐圧性能から見て過剰圧力にならない範囲に制御できる。 A relief valve 7 is provided on the fuel pump 4 side of the fuel supply passage 5 with respect to the pressure regulating device 6 . As a result, when the fuel pressure rises to a high level, the relief valve 7 is opened to release the pressure. Therefore, the pressure of the fuel can be controlled within a range that does not become an excessive pressure in view of the pressure resistance of the piping.

燃料供給システム１は、燃料タンク２内の燃料をエンジン３へ供給する燃料供給通路５の途中に圧力調整装置６が設けられている。圧力調整装置６は燃料ポンプ４の作動時に燃料供給通路として機能し、燃料ポンプ４の停止時に燃料ポンプ４側への逆流を防止する逆止弁として機能する。これにより、圧力調整装置６内でのみ燃料供給通路５の下流側部分５ｂの残圧を保持するための油密を確保すればよく、圧力調整装置とは別に逆止弁を設けた場合のように、圧力調整装置内と逆止弁の２箇所においてそれぞれ油密を確保する必要がない。そのため、油密特性の向上を図ることができる。 The fuel supply system 1 is provided with a pressure regulating device 6 in the middle of a fuel supply passage 5 that supplies the fuel in the fuel tank 2 to the engine 3 . The pressure regulating device 6 functions as a fuel supply passage when the fuel pump 4 is in operation, and as a check valve that prevents reverse flow to the fuel pump 4 side when the fuel pump 4 is stopped. As a result, it is sufficient to ensure oil tightness for retaining the residual pressure in the downstream portion 5b of the fuel supply passage 5 only within the pressure regulating device 6, as in the case where a check valve is provided separately from the pressure regulating device. In addition, it is not necessary to ensure oil tightness at two locations, the inside of the pressure regulator and the check valve. Therefore, it is possible to improve the oil tightness.

燃料供給通路５のエンジン３付近には、高圧ポンプ１１が設けられている。高圧ポンプ１１により燃料供給通路５内の燃料の圧力の低下を抑制し、燃料の気化を防ぐことができる。 A high-pressure pump 11 is provided near the engine 3 in the fuel supply passage 5 . The high-pressure pump 11 can suppress the pressure drop of the fuel in the fuel supply passage 5 and prevent the vaporization of the fuel.

第２弁体３２は、弁座部３２ｃが球面状に形成されることにより調心機能を有している。開弁時に第２弁体３２の軸がホルダ４０の弁座部４０ｂに対してずれたとしても、第１弁体３１の弁部３１ｂの円錐面が第２弁体３２の弁座部３２ｃに着座することにより、軸のずれが修正される。第２弁体３２が調心されることにより、第２弁体３２とホルダ４０の弁座部４０ｂのシール性が向上する。 The second valve body 32 has an alignment function by forming the valve seat portion 32c into a spherical shape. Even if the axis of the second valve body 32 is displaced from the valve seat portion 40b of the holder 40 when the valve is opened, the conical surface of the valve portion 31b of the first valve body 31 is aligned with the valve seat portion 32c of the second valve body 32. Seating corrects for axial misalignment. By aligning the second valve body 32, the sealing performance between the second valve body 32 and the valve seat portion 40b of the holder 40 is improved.

［他の実施形態］
本明細書に開示の技術は、前記した実施形態に限定されるものではなく、その他各種の形態で実施可能である。また、実施形態で説明した外観、構成に限定されず、要旨を変更しない範囲で種々の変更、追加、削除が可能である。 [Other embodiments]
The technology disclosed in this specification is not limited to the above-described embodiments, and can be implemented in various other forms. Further, the appearance and configuration are not limited to those described in the embodiments, and various modifications, additions, and deletions are possible without changing the gist of the invention.

１燃料供給システム
２燃料タンク
３エンジン（燃料利用装置）
４燃料ポンプ
５燃料供給通路
６圧力調整装置
７リリーフ弁
２２主調圧室（第１室）
２３副調圧室（第２室）
２４背圧室
２５燃料入口
２６供給出口
２７還流出口
３１第１弁体
３１ａ貫通孔
３２第２弁体
３２ｃ弁座部（第１弁座）
３３大スプリング（第１付勢部材）
３４小スプリング（第２付勢部材）
３５規制部材
４０ホルダ
４０ｂ弁座部（第２弁座）
Ａ１第１受圧面積（第１弁体が第１室内の燃料から圧力を受ける受圧面積）
Ａ２第２受圧面積（第２弁体が第２室内の燃料から圧力を受ける受圧面積）
Ａ３第３受圧面積（第２弁体が第１室内の燃料から圧力を受ける受圧面積）
Ｐ１主調圧室（第１室）内の燃料の圧力
Ｐ２副調圧室（第２室）内の燃料の圧力 1 fuel supply system 2 fuel tank 3 engine (fuel utilization device)
4 fuel pump 5 fuel supply passage 6 pressure regulator 7 relief valve 22 main pressure regulation chamber (first chamber)
23 Auxiliary pressure regulating chamber (second chamber)
24 Back pressure chamber 25 Fuel inlet 26 Supply outlet 27 Recirculation outlet 31 First valve element 31a Through hole 32 Second valve element 32c Valve seat (first valve seat)
33 large spring (first biasing member)
34 small spring (second biasing member)
35 regulating member 40 holder 40b valve seat (second valve seat)
A1 First pressure-receiving area (pressure-receiving area where the first valve body receives pressure from the fuel in the first chamber)
A2 Second pressure receiving area (pressure receiving area where the second valve element receives pressure from the fuel in the second chamber)
A3 Third pressure receiving area (pressure receiving area where the second valve element receives pressure from the fuel in the first chamber)
P1 Fuel pressure in main pressure regulating chamber (first chamber) P2 Fuel pressure in sub pressure regulating chamber (second chamber)

Claims

In a fuel supply system that supplies fuel from a fuel tank to a fuel utilization device,
a fuel pump for pumping the fuel in the fuel tank to the fuel utilization device;
one fuel supply passage connecting the fuel pump and the fuel utilization device;
A pressure regulating device provided in the middle of the fuel supply passage is provided,
The pressure regulator is
a first chamber into which fuel flows from the fuel pump side;
a second chamber from which the fuel flows out to the side of the fuel utilization device;
a recirculation outlet for recirculating surplus fuel to the fuel tank;
a first valve body having a through-hole and connecting/blocking communication between the first chamber and the recirculation outlet;
a second valve body having a first valve seat on which the first valve body is seated, and for communicating and blocking communication between the first chamber and the second chamber;
a second valve seat on which the second valve body is seated;
The first valve body is biased in the valve closing direction, and when the first valve body and the second valve body are in the closed state, the second valve body is moved to the second valve body through the first valve body. a first biasing member that holds the valve seat in a seated state;
a second biasing member that biases the second valve body in the valve opening direction;
When the fuel pump is operated, the pressure of the fuel in the first chamber increases, so that the first valve body and the second valve body move together in the valve opening direction, and the second valve body moves in the valve opening direction. 2. A fuel supply system in which the valve opens away from the valve seat, the fuel supply passage passing through the first chamber and the second chamber communicates, and fuel is supplied to the fuel utilization device.

The fuel supply system according to claim 1,
The pressure regulator is
The second valve body includes a restricting member that restricts movement toward the first valve body,
When the pressure of the fuel in the first chamber further increases, the first valve body moves further in the valve-opening direction, while the movement of the second valve body is restricted by the restricting member. A fuel supply system in which a body moves away from the first valve seat to open the valve, and surplus fuel is returned to the fuel tank through the through hole and the return outlet.

The fuel supply system according to claim 1 or 2,
When the fuel pump is stopped, the first valve body and the second valve body are urged by the first urging member to close the valve, and the flow from the second chamber of the fuel supply passage to the fuel utilization device side is controlled. A fuel delivery system in which the pressure of the fuel is maintained within a predetermined range.

The fuel supply system according to any one of claims 1 to 3,
A fuel supply system, wherein a pressure receiving area of the first valve body that receives pressure from the fuel in the first chamber is larger than a pressure receiving area of the second valve body that receives pressure from the fuel in the first chamber.

The fuel supply system according to any one of claims 1 to 4,
A fuel supply system, wherein a relief valve is provided on the fuel pump side of the fuel supply passage relative to the pressure regulator.