DE2248036A1 - PNEUMATIC SPEED REGULATOR FOR FUEL INJECTION PUMPS - Google Patents

Description

September 12, 1972 Ks / Wu

Attachment to

Patent and

Utility model registration

NIPPONDENSO CO., LTD.

1,1-chpme, Showa-cho, Kariya-shi Aichi-ken (Japan)

Pneumatic speed controller for fuel injection pumps

The invention relates to a pneumatic speed controller for fuel injection pumps with a vacuum chamber and a from this chamber, which is separated by a "membrane, and in communication with the outside air.

If you suddenly accelerate a previously used diesel engine, the fuel injection amount suddenly becomes larger than the amount of fuel required by the engine and this is known to produce black smoke.

3098U / 0938

_ 2 -

The object of the present invention "is to provide a pneumatic regulator for fuel injection pumps of this type to improve so that a response delay for the fuel control rod only when accelerating suddenly of the engine, the sudden increase in the amount of fuel injection is prevented and the. amount of fuel injected by the engine is gradually increased, so that the expulsion of the black smoke when suddenly accelerating the Motor can be prevented.

This object is achieved in that the chamber has a small bore and one opening towards the chamber as a connection to the outside air Has check valve.

In the following the invention is illustrated with reference to one in the drawing Embodiment explained in more detail.

Show it:

Figure 1 shows a section through a pneumatic controller, attached to a fuel injection pump,

Figure 2 is a characteristic diagram of the mode of operation of the controller,

In Figure 1, 1 is a pump housing, 2 ¹ is a controller housing,

2 is a vacuum chamber of the pneumatic regulator, 4 is one Diaphragm connected by a rod 6 to the fuel control rod

3 of the injection pump is connected. When the fuel control rod 3 moves to the left in Figure 1, the fuel injection amount increases. The vacuum chamber 2 is formed by the above-mentioned membrane 4 and the regulator housing 2 '. The vacuum chamber 2 is connected by a line pipe 10 to a venturi, not shown, arranged in the suction line of the internal combustion engine. This generates a negative pressure in the negative pressure chamber 2, which is in equilibrium with a control spring 5. The membrane 4 separates a chamber 12 opposite the vacuum chamber 2 from the vacuum chamber 2. 7 is a small bore with the diameter d and 8 is a non-return valve.

309814/093

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valve, which consists of a valve body 11 and a weak spring 9 acting on this valve body 11 and so on is built in that it opens in the direction of the chamber 12.

The mode of operation of the example described above will now be explained in detail below. In FIG. 2, the negative pressure Λ Ρ generated by the Venturi is plotted on the ordinate axis. The position RW of the fuel control rod 3 is plotted on the right-hand side of the abscissa axis and the pump speed Ii is plotted on the left-hand side of the abscissa axis. On the right side of the abscissa axis we have an increase in fuel in the direction of the arrow. Θ and © ^ in the figure (Θ - <θ ^) express the opening angle of a throttle valve built into the Venturi. First of all, during slow idling, the negative pressure A P and the spring 5 in position b of the control rod 3 and b 'of the throttle valve (FIG. 2) are in equilibrium. If there is then a sudden acceleration, the negative pressure Δ P decreases up to the position a or a '. If we now assume that the membrane 4 is displaced to the left in FIG. 1, the small bore 7 provided in the wall of the chamber 12 causes the air flowing out of this chamber to be throttled and thereby damped acts, so that time is needed for the displacement of the membrane 4, that is to say for the displacement of the fuel control rod 3 in FIG. 1 to the left. Since the amount of fuel injected only increases very slowly, that is to say gradually, and there is no excess, this method is effective as a measure against black smoke. In normal operation, the change in the negative pressure Λ P takes place only very slowly and the membrane 4 follows accordingly and thus responds to the usual changes in speed. The above-mentioned check valve 8 is installed in the regulator housing 2 'in the region of the chamber, so that at. the control of the high speeds, the response of the speed control (reduction) takes place quickly, because when the membrane 4 moves in the direction of the vacuum chamber 2, there is no air damping.

309814/0938

In the above-described pneumatic regulator according to the present invention, since a small hole 7 (throttle hole) and a check valve 8 are provided in the chamber opposite the vacuum chamber 2 and separated therefrom by the diaphragm 4, black smoke when a diesel engine is suddenly accelerated can be prevented . In normal operation, on the other hand, the controller retains its control effect in the manner customary up to now. / ^ ■

3U3614 / 0938

Claims (1)

claim Pneumatic speed controller for fuel injection pumps with an overpressure chamber and one of these through a membrane torn, in connection with the outside air chamber, characterized in that the chamber (12) as a connection to Outside air has a small bore (7) and a check valve (8) that opens towards the chamber (12). ^ Blank page