Pumps – Expansible chamber type – Pumping member position controlled port
Patent
1987-11-18
1989-07-25
Smith, Leonard E.
Pumps
Expansible chamber type
Pumping member position controlled port
F02M 5924, F02M 5944
Patent
active
048508233
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention is based on a fuel injection pump.
In slide-controlled fuel injection pumps, the axial position of the control slide usually determines the start of injection or the end of injection. However, there are also such pumps in which the injection quantity is controlled by means of the axial position of the control slide. In any case, an inexact axial position of the control slide has disadvantageous consequences for the quality of injection, which has immediate consequences for the combustion, with the result that the engine runs untrue because of the incorrectly timed injection or runs too quickly or two slowly because of the inexact metering quantity.
In a known fuel injection pump of this type (EP-A 0 181 402), the adjusting bolt engages in the cross groove of the control slide with a spherical head so that there is a punctiform contact between the head and the groove surfaces, which, with the long operating life and high vibration load of these actuating elements, leads to a premature wear and, accordingly, to an undesired play between the head and the groove surfaces with corresponding errors in the fuel control. The installation position of the adjusting bolt is fixed during adjustment, since, because of the eccentric arrangement of the head, the adjustment of the stroke position of the control slide is effected by means of turning the adjusting bolt, with subsequent checking. The play which occurs because of wear, however, works against this adjustment with the results mentioned above.
In another known fuel injection pump of this type (DE-A35 22 414), the adjusting bolt is arranged at a clamping ring so as to be fixed with respect to rotation relative to it; the clamping ring serves as a fastening part and grips the round rotating shaft in a clamp-like manner. The required adjustment can be carried out in a relatively simple manner by means of rotating the clamp on the rotating shaft, but there are also other disadvantages besides the one already mentioned, in that the transmission of force between the adjusting bolt and the respective surfaces of the cross groove is effective in a punctiform manner, since the adjusting bolt is constructed as a rotating part. Accordingly, since the contact is only punctiform, a correspondingly quick and severe wear also occurs in this case on the adjusting bolt as well as on the assigned groove surfaces.
SUMMARY OF THE INVENTION
The fuel injection pump according to the invention achieves substantially less wear because of the line contact between the slide shoe and the cross groove surface, so that no only can a longer service life of these transmission members be achieved, but the quality of the fuel control is also substantially improved.
According to another construction of the invention, the slide shoe is secured against axial displacement on the stud, which can be effected in an advantageous manner by means of a pin which is arranged in the slide shoe so as to be parallel to the contact surfaces of the slide shoe and which engages in an annular groove or cross hole or tangential cross groove arranged in the stud. By means of this, a securing is provided in the axial direction which is not favorable in terms of production, but also causes a minimum of friction between the stud and slide shoe. If the adjusting bolt is connected with the rotating shaft in a known manner (DE-A-35 22 414) by means of a fastening part so as to be fixed against rotation relative to it, and if the pin engages in the cross hole or cross groove at the stud in order to secure the position, the limited rotational play prevents a tilting or jamming of the slide shoe and facilitates the "blind assembly", since the sliding block cannot rotate out of its installation position to an undue extent and can accordingly be easily inserted into the cross groove of the control slide.
Other advantages and advantageous constructions of the invention can be discerned from the following description, the drawing and the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
T
REFERENCES:
patent: 2564830 (1951-08-01), Bremser
patent: 2905020 (1959-09-01), Ziesche
patent: 3385221 (1968-05-01), Parks
patent: 4661051 (1987-04-01), Nakamura
patent: 4706626 (1987-11-01), Hafele et al.
Guntert Josef
Hafele Walter
Kramer Manfred
Robert & Bosch GmbH
Smith Leonard E.
Striker Michael J.
LandOfFree
Fuel injection pump for internal combustion engines does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Fuel injection pump for internal combustion engines, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Fuel injection pump for internal combustion engines will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2354085