JPH0231552Y2 - - Google Patents

Description

[Detailed explanation of the invention] The fuel injection pump of a car equipped with a diesel engine increases the output of the engine as much as possible as long as the condition of avoiding the emission of highly concentrated exhaust gas (especially black exhaust gas) is met. However, if the engine is equipped with a supercharger and the fuel injection pump is equipped with a boost compensator, the situation is somewhat different, and the adjustment is made so that problems do not occur for normal driving. Even if the fuel injection pump is adjusted, if the accelerator pedal is depressed rapidly while idling, the interlock mechanism between the boost compensator diaphragm and the fuel injection pump control rack will overrun, causing the system to fail to meet regulations. Unacceptably high concentrations of exhaust gas are often generated. In other words, the rate of increase in boost pressure P
If dp/dt is particularly large, the above-mentioned interlocking mechanism will overrun due to its inertia, and the amount “ΔS+” will exceed the amount ΔS corresponding to the boost pressure increase amount ΔP.
Here, "ε" is the overrun amount, and the control rack of the fuel injection pump is moved to increase the injection amount by an amount corresponding to "ε". Note that when the accelerator pedal is gently pressed If the engine is stepped on, “dp/dt≒0” and “ε≒0” and no deterioration of the exhaust color will occur.

This proposal is based on the fact that the cause of the deterioration of the exhaust color that occurs when the accelerator pedal is depressed is due to an overrun of the interlocking mechanism between the boost compensator diaphragm and the fuel injection pump control rack, and as explained in the diagram below. ,
An electromagnet is provided to apply an attractive force to the diaphragm for a short period of time when the accelerator pedal is depressed, thereby avoiding the occurrence of this overrun.

In FIG. 1, 1 is a boost compensator, 2 is a boost pressure introduction pipe, 3 is an operating chamber of the boost compensator, 4 is a diaphragm of the boost compensator, and 5 is an output member attached to the diaphragm of the boost compensator.

In order to avoid the above-mentioned overrun of the interlocking mechanism, an electromagnet 6 that attracts the iron piece 8 attached to the diaphragm 4 is built into the boost compensator 1.

FIG. 2 is an operating circuit diagram of the electromagnet 6. In this figure, 7 is a biasing wire, and 9 is a contact on the operating circuit of the electromagnet 6. The contact 9 is arranged in the vicinity of the accelerator pedal or the member moved by the accelerator pedal and is closed only when the engine is idling. It is desirable that the contact 9 be of a non-contact type. 10 is a power supply, and 11 is a capacitor connected in parallel to the contact 9. The contact 9, which is closed in the idling state, is opened by pressing the accelerator pedal, but even after the contact 9 is opened, the electromagnet 6 remains energized for only a short time (for example, 0.05
seconds). "Rapid depression of accelerator pedal → overrun of interlocking mechanism → worsening of exhaust color"
This process that causes such undesirable results can be avoided by continuing (extending) the energized state of the electromagnet 6. The overrun of the interlocking mechanism is avoided by maintaining (extending) the energized state of the electromagnet 6. This is because overrun of the weighing platform that occurs when an article is dropped from a high place and placed on the weighing platform of a platform scale is It is easy to understand if you think of it in conjunction with the avoidance of clamping the weighing platform in advance before dropping the object, or releasing the clamp on the weighing platform after the object reaches the weighing pan. .

The device according to the present invention described above can be described as a device for preventing the occurrence of "free accelerator smoke", and does not interfere with the operation of the fuel injection pump under adjusted conditions during normal operation. be.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view showing the boost compensator portion of the device according to the present invention, and FIG. 2 is an operating circuit diagram of the electromagnet shown in FIG. 1. DESCRIPTION OF SYMBOLS 1... Boost compensator, 2... Boost pressure introduction pipe, 3... Working chamber, 4... Diaphragm, 5... Output member, 6... Electromagnet, 7... Biasing wire ring, 8... Iron piece, 9... Contact, 10... Power supply,
11... Capacitor.

Claims (1)

[Scope of utility model registration request] An iron piece 8 is attached to the diaphragm 4 of the boost compensator 1 that operates the output member 5 in response to boost pressure, and an electromagnet 6 that attracts the iron piece 8.
is built into the boost compensator 1, and a contact 9 that is closed when the engine is idling and is switched to the open state when the accelerator pedal is depressed is provided on the operating circuit of the electromagnet 6, and is connected in parallel to the contact 9. A boost compensator device for a fuel injection pump, characterized in that a capacitor 11 is provided, which extends the energized state of an electromagnet 6 by a minute time when the contact point 9 is connected to the capacitor 11.