Internal-combustion engines – Charge forming device – With fuel pump
Patent
1998-08-19
2000-02-08
Miller, Carl S.
Internal-combustion engines
Charge forming device
With fuel pump
123470, 73119A, F02M 3704
Patent
active
060217626
DESCRIPTION:
BRIEF SUMMARY
PRIOR ART
The invention is based on a process for leak testing in a fuel injection pump, with a pump housing that can be plugged into a motor housing and in its jacket face that is encompassed by the wall of a recess of the fuel injection pump in the motor housing. The fuel injection pump has an inlet for fuel to be supplied to a pump work chamber of the fuel injection pump and an outlet for fuel to be returned, which outlet feeds into a first annular chamber that is sealed in relation to the outside by means of a first seal clamped between the jacket face of the pump housing and the wall of the recess and is sealed in relation to the inlet by means of a second seal clamped between the jacket face of the pump housing and the wall of the recess, and the fuel supply of the inlet is carried out from a second annular chamber that is disposed between the jacket face of the pump housing and the wall of the recess and is divided from the first annular chamber by means of the second seal and is sealed on the other end in relation to the outside by means of a third seal clamped between the jacket face of the pump housing and the wall of the recess, wherein the inlet and the outlet communicate with each other inside the pump housing at least by way of a throttle connection.
Fuel injection pumps of the above-mentioned type with annular chambers, which have to be leak tested, have been disclosed for example by means of EP 0 461 212. In the execution of a leak test, problems arise by virtue of the fact that inside the pump housing between the inlet and the outlet, hydraulic short circuits exist at least by way of throttle connections so that an isolated test of the above-mentioned seals can only be partially executed. The seals disposed toward the outside, the above-mentioned first seal and the third seal, can be tested without great trouble. Due to the hydraulic short circuit, though, the testing of the second seal as a seal between the first annular chamber and the second annular chamber is not easily possible. To make things more difficult, a seal of this kind should be able to be leak tested, particularly upon final installation of the fuel injection pump into the motor housing. However, the leakage quantity that flows, e.g. via a throttle gap at the pump piston of the fuel injection pump or via a throttled cooling circuit, inhibits this testing.
ADVANTAGES OF THE INVENTION
The process according to the invention has the advantage that a leak testing of the second seal can be easily and reliably executed. Since the material introduced into the outlet at the pump housing dissolves when the fuel heats up, the fuel injection pump advantageously no longer needs to be taken out in order to remove this sealing material, which would have the risk that a previously established leakproofness would be lost after reinstallation. A design of this kind would also be connected with additional assembly costs. In accordance with the process set forth herein, the full functioning of the fuel injection pump can advantageously be produced very rapidly in such a way that the closure of the outlet is completely and immediately neutralized and thus the action of a delivery pump supplying the fuel injection pump with low pressure fuel is not impaired. With the subsequent heating, the material dissolves in the fuel and is supplied for combustion along with the fuel.
When testing, the outlet is advantageously closed with the material. It is also possible, though, with the corresponding embodiment of the inlet, to close the inlet as well for testing purposes.
A fuel injection pump for carrying out the process sets forth in that the outlet or the inlet into which the material is to be introduced widens toward the first or second annular chamber so that when pressure acts on the respective annular chamber, this material closes the outlet or the inlet in relation to the pump interior after the fashion of a check valve. The embodiment of the outlet or the inlet at this point is carried out such that they narrow in a funnel shape toward the p
REFERENCES:
patent: 3125028 (1964-03-01), Reiners
patent: 4246877 (1981-01-01), Kennedy
patent: 4428228 (1984-01-01), Banz Haf
patent: 4559815 (1985-12-01), Needham
patent: 4571161 (1986-02-01), LeBlanc
patent: 5007401 (1991-04-01), Grohn
patent: 5195362 (1993-03-01), Eason
patent: 5325834 (1994-07-01), Ballheimer
patent: 5402944 (1995-04-01), Pape
patent: 5625946 (1997-05-01), Wildeson
patent: 5715786 (1998-02-01), Seiberth
patent: 5720436 (1998-02-01), Buschor
patent: 5730101 (1998-03-01), Aupperle
Schaible Dieter
Tricasi Vito
Zeidler Dirk
Greigg Edwin E.
Greigg Ronald E.
Miller Carl S.
Robert & Bosch GmbH
LandOfFree
Seam test on a fuel injection pump, and the fuel injection pump does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Seam test on a fuel injection pump, and the fuel injection pump , we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Seam test on a fuel injection pump, and the fuel injection pump will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1673642