JPS6170168A - Abrasion-dust removing apparatus for magnetic disc for fuel injection pump - Google Patents

Abstract

PURPOSE:To control the injection amount and injection timing with high precision by generating the always stable angular signals by blasting the fuel jet flow at least onto a part of a magnetic disc, in an angle detector. CONSTITUTION:In a magnetic disc 201, N and S electrodes are formed alternately, and the variation of the magnetism is detected as the variation of resistance of a magnetic resistor 203. A drum 202 is installed onto a coupling 200 and revolves integrally with a rotor 1. Minute abrasion dusts are formed the revolution part and contact part of a fuel injection pump and are attached onto the magnetic disc 201. The pressure supplied from a feed pump is introduced into a passage 204 and formed to the jet flow of fuel in a jet 205, and blown onto the surface of the magnetic disc 201, and then removes the attached abrasion dusts. Therefore, the always stable angular signal can be generated, and the control of injection amount and injection timing with high precision is permitted.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a fuel injection pump, and in particular to a magnetic disc for a fuel injection pump that is suitable for removing abrasion powder adhering to a magnetic disc that generates an angle signal. This invention relates to a wear debris removal device.

[Background of the invention]

For the purpose of controlling the injection amount and injection timing with high accuracy and high response, Japanese Patent No. 55-130684 proposes an injection pump in which the injection amount and injection timing are controlled entirely by the amount of fuel measured by two electromagnetic valves.

For more precise control, it is necessary to precisely control the opening timing of the two electromagnetic valves, and an angle signal with high resolution is required.

Conventionally, angle signals have been detected using geared gears and magnetic pickups, but there is a limit to the mounting space available for geared gears, and there is also the drawback that the signal is weak at low speeds. Ta.

The combination of the magnetic disc and the magnetoresistance effect makes it easy to obtain high-resolution angle signals and enables highly accurate control, but abrasion particles generated from inside the pump adhere to the magnetic disc and reduce the output. There were disadvantages of signal degradation and damage to the magneto-resistive effect of the detector.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems and provide a magnetic disk that can always generate stable angle signals.

[Summary of the invention]

The fuel flow is sprayed onto the rotating magnetic disc in opposite directions in the rotational direction, so that abrasion particles inside the pump adhere to it and have the effect of constantly cleaning the surface of the disc.

[Embodiments of the invention] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view of an injection pump embodying the present invention, and the operation of the injection pump will be explained.

The rotor 1 is driven by an engine (not shown) through a shaft cup link 200 to maintain a timing relationship with the engine. A pair of plungers 3 are provided on the rotor head 2 of the rotor 1, a cam link 4 is provided on the outer periphery of the rotor 1 to allow the plunger 3 to move all the way inward, and a cam link 4 is provided on the outside of the grunge 3.
A roller 5 that makes contact with the roller 5 and a roller unit 6 that receives the roller 5 are arranged.

Next, the operation during fuel supply will be explained. ...The injection quantity control solenoid valve 8 (abbreviated as Q valve) and the injection timing control solenoid valve 9 ('['
Fuel is supplied to the supply passage 10 from a feed pump (not shown) to the valve.

In this state, when a control pulse is applied to the Q valve 8.1 cell 9, an amount of fuel proportional to the control pulse is measured and sent to the downstream side of each electromagnetic valve.

The fuel metered by the Q-valve 8 is sent to the first pressurizing chamber 14 via a Q-valve supply passage 12 provided in the sleeve 11 and Q-valve rotating supply ports 13 of the same number as the number of cylinders of the rotor 1. 1st
The fuel supplied to the pressurizing chamber 14 moves the shuttle 15 to the rotor head 2@, and as the shuttle 15 moves, the fuel in the intermediate chamber 16 is transferred to the rotary communication passage 17 of the rotor 1,
The discharge communication passage 18 of the tube 11 and the passage a19t are discharged to the pump internal low pressure section 20 through the passage a19t. With the above operation, Q valve B
The fuel metered in is supplied to the first pressurizing chamber 14.

Next, the amount of fuel measured by the T-valve 9 is transferred to the second pressurizing chamber 23 provided in the rotor 1 through the T-valve supply passage 21 of the sleeve 11 and the T-valve rotating supply ports 22i, which have the same number as the number of cylinders in the rotor 1. Supplied. The fuel it supplied to the second pressurizing chamber 23 is forced to spread toward the plunger 3, roller juro, and roller 5tl side. The spread tip position of the roller 5 is proportional to the amount of fuel supplied from the T-valve 9, that is, the control pulse applied to the T-valve 9. With the above, each pressurizing chamber 14 is connected to the Q valve 8 and the T valve 9.
Supply to 23 will end.

Points to note in this supply state are: (1) The movement of the shuttle 15 toward the rotor head 2 is proportional to the fuel cover from the Q valve 8 and, in turn, to the control pulse to the Q valve 8. (2) The spread position of the tip of the roller 5 is proportional to the control pulse applied to the T-valve 9 as described above.

It is clear that when fuel is supplied to '17, all the boats involved in compression and injection formed by the rotor 1 and sleeve 11 are in a closed state as shown in FIG.

The embodiment of the present invention is for a four-cylinder engine, and as shown in the first diagram, when the rotor 1 rotates approximately 45 degrees, the first pressurizing chamber 14 and the second
7111 This is the compression and injection stroke of the fuel supplied to the pressure chamber 23.

Q valve supply passage 12 involved in supply from Q valve 8 and T valve 9
, the discharge communication passage 18, and the T-valve supply passage 21 are all closed at the outer peripheral surface of the rotor 1. During this compression and injection stroke, no control pulse is applied to each solenoid valve, but this is to avoid receiving high pressure from the respective pressurizing chambers 14 and 23. Ports involved in compression and injection are formed through the injection ports 24 of the rotor 1 and the discharge ports 25 of the same number as the number of cylinders provided in the sleeve 11, and the T valve rotation supply port 22 of the rotor 1 and the sleeve 11 have the same number of discharge ports 25 as the number of cylinders provided in the sleeve 11. The compression communication passage a26 flows,
A communication path 27 formed on the surface of the sleeve 11, a compression communication path b28, and a rotation communication path 1 formed in the rotor 1.
7 are all in communication with each other, and the second pressurizing chamber 23 and the intermediate chamber 16 are in communication with each other. Furthermore, the rotary discharge port 30 of the rotor 1 discharges surplus fuel from the second pressurizing chamber 230 through the intermediate chamber 167.
and the fixed discharge port 31 of the sleeve 11 communicate with each other, and this passage communicates from the surplus fuel discharge passage 100 of the hydrolitter head 7 to the main discharge passage 101.

However, at the start of compression and injection, the intermediate chamber 16 and the rotary discharge port 30 are closed only by the surface of the shuttle 15, and there is no flow.

From the first pressurizing chamber 14, there is an inlet 34 of the shuttle 15, a circumferential groove 35, a pressure outlet 36 of the rotor 1, a high pressure fixed outlet 37 of the sleeve 11, a second fuel discharge passage 102 of the hydroliter head 7, A passage communicating with the main discharge passage 101 is formed, but similarly to the above, at the start of compression and injection, the circumferential groove 35 of the first pressurizing chamber 14 and the high pressure discharge port 36 of the rotor 1 are closed by the surface of the juttle 150. ing.

The above are the passage configurations for the compression and injection strokes and the compression start state.

In this state, the rotor 1 rotates, and eventually the roller 5 starts to come into contact with the same number of protrusions on the inner periphery of the cam ring 4 as the number of cylinders. This operation causes roller 5, roller juro,
The plunger 3 is pushed back inward and includes a fuel injection port 24 leading from the second pressurizing chamber 23 to the intermediate chamber 16, a discharge port 25 provided in the sleeve 11, and a connection port 44 provided in the hydrolitter head 7, not shown. Injection begins from the delivery pulp to the engine fuel chamber via the high-pressure pipe injection valve. In this series of operations, the timing at which injection from the injection valve starts is the timing at which contact between the cam link 4 and the roller 5 starts, considering pressure propagation within the high-pressure pipe.

Therefore, the fuel injection timing (timing when injection starts) can be controlled by controlling the contact start point between the cam ring 4 and the roller 5, and this contact start point is controlled by the spread tip position of the roller 5, and the T valve 9 The amount of fuel 1t (=metered amount of TTe3) supplied to the second pressurizing chamber 23 is 1t, and the injection timing can be easily controlled by the width of the control pulse applied to the T-valve 9.

If the above-mentioned injection start area injection progresses, naturally the first
In response to the injection from the pressurizing chamber 14, the nyatle 15 moves upward in FIG.
When the predetermined injection from the first pressurizing chamber 14 is completed, the circumference 135 of the shuttle 15 and the high-pressure discharge port 36 of the rotor 1 are brought into communication with each other due to the movement of the shuttle 15, and the fuel in the first pressurizing chamber 14 is released to the low-pressure part, resulting in a pressure drop. Injection ends.

Furthermore, if there is compression from the second pressurizing chamber 23, the
moves upward in FIG. 1, and eventually the lower end surface of the shuttle 15 brings the intermediate chamber 16 and the rotary communication passage 17f of the rotor 1 into a state of communication, thereby discharging the excess fuel in the second pressurizing chamber 23 used for injection timing control. Then, the operation for one cylinder is completed.

In the above series of operations, the injection amount can be controlled by the amount of fuel supplied to each pressurizing chamber from the two solenoid valves, and the injection timing can be controlled for each t-1 injection, but in order to perform accurate control, it is necessary to The following conditions are necessary.

(1) Determine the opening timing of the solenoid valve (starting timing of supply to the pressurizing chamber) based on the sieve resolution.

This is because the cross-sectional area of each supply passage formed by the rotor l and the sleeve 11 changes for each unit angle, and the supply cover changes while the metering time with the solenoid valve is constant due to the passage configuration, resulting in the injection amount and injection timing. This is to influence the Therefore, it is necessary to drive the electromagnetic valve at the optimum opening timing in accordance with the operating conditions, and for this purpose a high-resolution angle signal is required.

Since the equivalent time per unit angle changes depending on the rotation speed,
Although time control is advantageous for electromagnetic valve control, it is clear that angle control, which is not affected by rotational speed, is desirable for detecting and setting arbitrary positions (valve opening timing).

Figure 2 shows the 2-2 cross section of Figure 1, and Figure 3 shows the magnetic disk 20.
1 is an indication of the state of the drum 202 in which the drum No. 1 is formed.

This magnetic disk 201t'j has N-poles and S-poles alternately formed, and the change in magnetism caused by this N-8 is detected as a change in resistance due to the magnetoresistive effect 203.

Further, the drum 202 including the entire magnetic disc 201 is attached to a coupling 200 and can rotate together with the rotation of the rotor 1.

Here, the rotating parts inside the pump body (rotor 1 and sleeve 1)
1) Contact part (cam ring 4 and roller 5, roller juro)
Fine abrasion powder, ie, iron powder, is generated from the magnetic disk and adheres to the magnetic disk 201 described above. It is obvious that this adhesion t becomes considerably large over time, which adversely affects the signal from the magnetoresistance effect 203 and further damages the magnetoresistance effect 203, which can be fatal to the pump. Become.

As shown in FIGS. 1 and 2, the present invention introduces the supply pressure from a feed pump (not shown) from the supply passage 10 through a passage 204, and further converts it into a jet of fuel using a jet 205. This provides a cleaning effect on the surface so that attached abrasion powder is removed and a stable angle signal is always generated.

The source of the fuel that becomes the jet flow may be other methods. Furthermore, the jet 151f from this jet 205
, in order to make it more effective, the jets are made to face the rotational direction of the drum 202, and the magnetic disk 201 on the second side of the drum 202 is
It is arranged in the tangential direction of .

The above is a method in which the magnetic disk 201 is formed on the outer periphery of the drum 202, but as shown in FIGS.
It can also be applied to the disk type attached to the side of 02.

[Effect of release]

can be prevented, a stable angle signal can always be generated, and the injection amount,
Highly accurate control of injection timing is possible.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA in FIG. 1, FIG. 3 is a state diagram of a magnetic drum including a magnetic disc, and FIG. The longitudinal sectional view of the example, FIG. 5, is a BB sectional view of FIG. 4. 8... Injection amount control solenoid valve, 9... Injection timing control solenoid valve, 200... Cup link, 201... Magnetic disc, 202... Drum, 203... Magneto-resistive effect, 2
04...Aisle, 001 σ1 υ ~

Claims (1)

[Claims] 1. A magnetic disc for a fuel injection pump, characterized in that a fuel injection pump operates in synchronization with an internal combustion engine, and is characterized in that it sprays a jet of fuel onto at least a portion of the magnetic disc. wear debris removal device.