(19)
(11) EP 1 103 722 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
05.02.2003 Bulletin 2003/06

(43) Date of publication A2:
30.05.2001 Bulletin 2001/22

(21) Application number: 00125242.8

(22) Date of filing: 23.11.2000
(51) International Patent Classification (IPC)7: F04B 53/16, F04B 53/12
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 25.11.1999 JP 33391999

(71) Applicant: MIKUNIADEC CORPORATION
Iwate-gun, Iwate-ken 020-0173 (JP)

(72) Inventors:
  • Kubota, Kenichi
    Morioka-shi, Iwate (JP)
  • Takehana, Norio
    Shizukuishi-machi, Iwate-gun, Iwate (JP)
  • Shichi, Makoto
    Iwate-gun, Iwate (JP)

(74) Representative: VOSSIUS & PARTNER 
Siebertstrasse 4
81675 München
81675 München (DE)

   


(54) Plunger type pump


(57) In a plunger pump a communication passage (72) is arranged in a plug (64) for closing a cylinder storing hole (16). The plug (64) is movable relative to the cylinder assembly (24) by a spring. An O-ring (74) for preventing the leakage of a fuel from faces opposed to the cylinder assembly (24) and the plug (64) is attached to the plug (64). When the fuel pressure within a fuel passage (32) is equal to or lower than a predetermined pressure, the O-ring (74) comes in contact with the cylinder assembly (24) by the spring (80), and the fuel leakage from the above opposed faces is prevented by the O-ring (74). If the fuel pressure within the fuel passage (32) is equal to or higher than the predetermined pressure, part of the fuel is vented to the exterior to reduce fuel pressure.






Search report