KR930006059B1 - Liquid fuel pumping apparatus - Google Patents

Abstract

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Description

Liquid fuel pumping device

1 shows a pumping device according to the invention mounted on an engine.

2 is a cross-sectional view of the side of the device.

3 is a cross-sectional view taken along the line 3-3 of FIG.

4 and 5 are cross-sectional views partially cut along lines 4-4 and 5-5 of FIG.

6 shows an enlarged view of the valve shown in FIG. 2 forming part of the device.

7 shows a block diagram of the electric circuit for controlling the actuator.

FIG. 8 shows the operating characteristics of the valve shown in FIG.

* Explanation of symbols for main parts of the drawings

10: liquid fuel pumping device 12: plunger (plunger)

21: outlet valve 22: valve operating position

30: core 32: winding

37, 38: transducers 41, 42: detectors

The present invention relates to a liquid fuel pumping device for supplying fuel to an internal combustion engine, comprising: a plunger reciprocating in an aperture, an outlet from the aperture through which fuel can flow during an internal temperature of the plunger; It consists of an electromagnetically actuated outlet valve that regulates the flow of fuel through the passage connected to the aperture and is closed during the inner movement of the plunger to flow the fuel through the outlet.

With such a device, the closure period of the valve considered in the plane of motion of the plunger determines the amount of fuel that travels through the outlet. This valve needs to be operated very quickly during use, and the supply of current to the valve has typically been controlled based on the time considered in terms of the plunger motion. However, this control method has a number of disadvantages, mainly due to the structure of the valve. Since the actuator of the valve is electromagnetically operated and includes a winding and an iron circuit, the valve takes a length of time because the valve is gradually formed in the iron circuit of the magnetic flux. A limited time is also required for the valve to open, which is usually done by the action of a spring. Thus, to say that the valves of a batch of valves are identical, the valves must be made with very small tolerances. In addition, the change in the spring force will change the opening and closing characteristics of the valve during use of the valve. Apart from the configuration of the actuator, tolerances in the valve structure will change the operating time, eg the overall motion of the valve. In addition, external factors such as, for example, fluctuations in supply voltage and variations in the response and characteristics of the associated electrical control circuits will also affect the operation of the valve.

It is an object of the present invention to provide a device of the above kind in a simple and convenient form.

According to the invention, a device of the above kind comprises means for responding to the operation of the valve to supply a signal indicating the state of the valve, which signal is supplied to the control circuit of the valve actuator during use.

Hereinafter, an example of an apparatus according to the present invention will be described with reference to the accompanying drawings.

1 to 6, there is shown a fuel pumping device in the form of a rotary distributor. The apparatus comprises a body 1 composed of various parts, in which a sleeve for supporting a rotating cylindrical distributor member is mounted. Including the body 1, there is mounted a sleeve for supporting the rotating cylindrical distributor member. The main body 1 is mounted on the engine 2, which has a drive shaft 3 connected to the distributor and the rotating part of the engine, thereby allowing the distributor member to be driven in a constant time relationship with the engine. The outlet port 4 of the punching device is connected to the injection nozzle 5 of the engine. The distributor member 6 is provided with a cross bore, which is equipped with a pair of pumping plungers 7 to move inward by the action of the cam protrusion 8 on the annular cam 9 during the rotation of the distributor member. . The cam projection transmits motion to the plunger via the follower, which is a roller held in a shoe mounted for radial motion in an annular drive member 11 connected to the drive shaft 3. (10).

The bore comprising the plunger 7 is in communication with a central passage 12 formed in the distributor member, which passage is in communication with a radially extending supply passage 13. This can in turn lead to the outlet port 4 (of FIG. 5), which is spaced at an angle around the axis of rotation of the distributor member during the inner movement of the pumping plunger.

At other points, the central passage 12 communicates with the plurality of inlet passages 14, which in turn can lead to the inlet port 15 connected to the outlet of the low pressure fueling pump, generally indicated by reference numeral 16. have. The communication of one of the inlet passages 14 with the inlet port 15 occurs during the movement of the plunger 7 outwardly by the cam projection, during which the bore including the plunger 7 is completely filled with fuel. .

The central toro 12 communicates with a circumferential groove 16A formed in the periphery of the distributor member, and this groove is always in communication with the outlet valve, generally indicated by 21, via the outlet passage 17. do. 6 shows the outlet valve in more detail, which is generally controlled by an electromagnetic actuator indicated by reference numeral 22. Instead of continuous communication as described above, it is possible for the central passage 12 to communicate with the outlet valve via the port.

In use, the distributor member rotates in the direction of the arrows indicated in FIGS. 4 and 5, and as shown in FIG. 3, the roller 10 is associated with the portion of the cam protrusion 8. The supply passage 13 starts to move out of match with the outlet port 4 and the inlet passage 14 starts to move in line with the inlet port 15. As the distributor member rotates, the fuel will be supplied to the bore containing the plunger and it will move outwardly as permitted by the cam protrusion. During the continuous rotation of the distributor member, the coincidence between the inlet passage 14 and the inlet port 15 is broken and the supply passage 13 moves to coincide with the next outlet port 4 so that the fuel is passed through the other injection nozzle to the engine. Will be provided. The injection nozzle receives fuel again and the cycle is repeated.

The amount of fuel supplied by the apparatus to the injection nozzle 5 of the engine is determined by the time taking into account the rotational angle of the distributor member 6, during which the outlet valve 21 is closed and the plunger moves inward. . Thus, if the outlet valve is closed through the complete inner movement of the plunger 7, the maximum amount of fuel that can be supplied by the device will be supplied to the injection nozzle. In practice, the amount of fuel supplied during normal operation of the engine is much less than the maximum amount and thus the valve will close for a shorter period of time. The timing of fuel supply start to the engine can be converted by adjusting a point in the pump's working cycle when the valve is closed.

As shown in FIG. 6, a slidable valve member 23 is included in the outlet valve hole 24. As shown in FIG. The valve member includes a head portion that is slightly larger than the diameter of the hole and that interacts with the base at the end of the hole. Under the head portion, a circumferential groove 25 is formed in the valve member, and the circumferential groove is formed with a circumferential groove 16A formed around the distributor member 11 by a passage (not shown) in a specific example. Communicating.

The valve member is biased to the open position by the spring 25A and moved to the closed position shown when power is supplied to the electromagnetic actuator. When the valve member is in the open position, the groove 25 is exposed to an outflow chamber 26 in communication with the outlet.

Control of the electromagnetic actuator is achieved by the control system described below, but as described above, the operation of the valve member depends on several factors. 8 shows the pulses 27, which are generated from transducers connected to the rotating part of the engine. This pulse is supplied to the control system, and a current indicated by reference numeral 28 is supplied to the actuator at a preset time after the start of this pulse. Since the actuator has a winding and an iron core, the current in the actuator winding slowly rises and the valve will not close until this current reaches a certain value. The operation of the valve member is shown at 29. The current pulse is reduced to a fixed value in order to economically use power and to reduce the amount of heat generated in the windings of the actuator. However, it can be seen that the valve remains closed. It can be seen that a certain time is required for the valve to be in the closed position, and another limited time is required for the valve member to move to the fully open position when the flow of current is stopped. As explained, the manufacturing tolerances greatly influence the time required for the valve member to move to the closed position after the flow of current begins, and taking into account these delays that change during use of the device, it feeds the control counter. Transducer is installed in the outlet valve. This transducer is shown in FIG. 6 and includes a core 30 that can move in a hollow winding 31 with a winding 32. It is possible to predict the exact moment of valve closure and valve opening from the signal generated by the transducer. In fact, fueling begins just before the valve is fully closed and lasts for a while after the valve begins to open. This results in pressurizing the fuel in the outlet passage 17 since the valve starts to restrict the fuel flow in the outlet passage as the valve is closed.

Referring to FIG. 7, the valve actuator 22 is shown in block form and is supplied with current by the power circuit 33. The power circuit is controlled by two calibration modules 34 and 35, the module 24 sends an "ON" signal to the power circuit and the module 35 "OFF" to the power circuit. ) "Signal. The module 34 corrects the timing change, that is, the starting point of supply of the fuel, and the module 35 corrects the change of the supply amount.

There is also provided a circuit 36 to which various engine operating variables, such as temperature, air inlet pressure and engine speed, as well as signals indicative of desired operating variables determined by the driver are supplied. This circuit determines the amount of fuel supplied to the engine in each supply stroke of the pump and also the fueling time to the engine based on the stored information. The circuit 36 is also supplied with two sets of timing signals from the transducers 37, 38 which are associated with the rotating parts of the pump and / or associated engine. One of these transducers, preferably the signal supplied by the transducer 37, is used as a speed signal. The transducer 37 is adapted to generate a continuous train of pulses at a relatively high frequency while the transducer 38 generates a marker pulse, which is generated once per pump of the pump. The number of display pulses is equal to the number of engine cylinders. The signal from transducer 37 is fed to a pair of counters 39 and 40 and the signal from transducer 38 is only fed to counter 39. Counters 39 and 40 also receive a signal from valve closure detector 41 that receives a signal from transducer 32 associated with the valve. Counter 40 receives a signal from valve open detector 42, which also receives a signal from transducer 37. The detectors 41 and 42 are installed in consideration of the fact that fuel supply starts before the valve is completely closed, and fuel supply continues even after the valve starts to open. In a representative example, a valve may be considered closed when it has moved up to 90% of its closed stroke and when it has moved up to 10% of its open stroke.

Counter 39 uses the signal from transducer 38 as a start count signal, the coefficient of which is the number of pulses supplied by transducer 37. The stop count signal is supplied by the detector 41 so that the count value generated by the counter 39 indicates the time required for the valve to close after the display hull generated by the transducer 38 as the angle of rotation of the engine. It is. The counter 40 uses the signal supplied by the detector 41 as the start count signal, and uses the signal supplied by the detector 42 as the stop count signal. Therefore, the count value generated by the counter 40 indicates the time when the valve is closed in terms of the engine rotation, and thus indicates the amount of fuel supplied to each engine cylinder.

The circuit 36 generates a desired timing signal and a desired valve closing cycle or fuel amount signal on the lines 43 and 44, respectively, and these signals are associated with the display signal. Lines 3 and 44 are connected to the input ends of comparators 45 and 46, respectively, and these comparators also receive signals from circuits 39 and 40, respectively.

The circuit 36 also supplies a pulse signal corresponding to the display pulse supplied by the transducer 38. This occurs earlier than necessary so that the normal time change can be adjusted, and the control value of the control signal for the thrust circuit 33 is supplied to the modules 34 and 35 for manufacturing tolerances and circuit changes.

Assuming that the moment and time when the engine is operating under steady-state conditions and the fuel amount are correct, the outputs of the comparators 45 and 46 are zero, so that the pulse signal supplied by the circuit 36 to the correction modules 34 and 35 Will not be affected by the module. If there is a time and / or fuel quantity error, the module 34, 35 modifies the pulse signals by an appropriate amount based on the signals supplied by the comparators 45, 46, so that the desired time and fuel quantity will be the next time fuel is supplied. Will achieve. In this respect, it should be noted that the correction module includes a memory element in which a record of the actual time and fuel amount is maintained with an error so that a correction to be supplied next time is possible. If the desired time and fuel amount change, the output signal supplied by one or two comparators changes to vary the degree of delay.

It is not always desirable for the device to fully compensate for errors during operation. for example. If a 1 degree time error occurs, it would be desirable to correct this twice in 1/2 degree to avoid overshooting. Determination of the amount of correction and the number of correction steps is made by a circuit in the correction module 34.

Claims (4)

Plungers reciprocating in the bore, outlet ports from the bore through which fuel can flow during the inward motion of the plunger, and control the flow through the passages connected to the bore and the outlet ports during the inward movement of the plunger. An electromagnetically actuated outlet valve, which may be blocked to cause a flow of fuel through, means for responding to the operation of the outlet valve to provide a signal indicative of the state of the valve, and a control circuit to which the signals are supplied And a control circuit for supplying fuel to the internal combustion engine, wherein the control circuit controls the operation of the valve. 2. The apparatus of claim 1, wherein the means for responding to the operation of the outlet valve comprises: a transducer having components that can move with the valve member of the outlet valve, and first and second detectors responsive to the signal of the transducer. And the first and second detectors supply a signal indicative of the actual closing and opening of the valve, respectively. 3. The apparatus of claim 2, comprising a counter, means for supplying a series of first pulses to the counter, and a desired valve closing period, the comparator in which the count value is compared with a signal that indicates the speed of the associated jin. Depending on the rotational speed, a signal supplied by the first detector is supplied to the counter start input terminal to the counter, a signal supplied by the second detector is supplied to a stop coefficient input terminal of the counter, Liquid fuel pumping device for indicating the period during which the balance is closed. 4. The apparatus of claim 3, further comprising means for supplying a series of second pulses generated at a preset engine position and a second counter for counting the series of pulses, wherein the second series of pulses comprise the second counter. And a signal from the first detector is applied to the count stop input of the second counter, and the count value of the second counter indicates a period required for closing the valve.

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