JPS6017924B2 - Engine oil pump abnormality detection device - Google Patents

Abstract

PURPOSE:To make it possible to accurately detect the flow of a minute quantity of low-pressure engine oil, by magnetically detecting the forced supply state of the oil.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device for detecting an abnormality in an engine oil pump of a two-stroke engine.

A two-stroke gasoline engine that mixes gasoline and oil and supplies the mixture to the engine using a separate lubrication system quickly ages if the supply of engine oil is cut off due to a failure in the oil supply system.

For this reason, always check the oil supply status, and if
If the oil supply stops, immediately (within 2 to 3 seconds)
It is necessary to stop the engine. However, when supplying oil to a two-stroke gasoline engine, the mixing ratio of gasoline and oil is 25:1 or 30:1.
etc., and the total amount of oil supplied is very small.

Particularly in small engines, the amount of oil supply and flow is extremely small, and the oil discharge pressure is also extremely low.
Incidentally, in the case of an 800cc class two-stroke gasoline engine, the oil supply flow rate per cylinder is approximately 13 to 133 c from idling to full throttle.
c/h, and the discharge pressure of this oil is approximately 0.5 c/h.
The pressure is very low, 2 to 0.1 kg/shore. For this reason, it operates sensitively to such small amounts and low pressure oil,
No inexpensive detector that can accurately detect oil flow has yet been proposed. The present invention has been newly developed in view of the above-mentioned points, and focuses on the fact that engine oil is supplied periodically according to the operating cycle of the engine oil feed pump, and magnetically controls the pumping state of the engine oil. The present invention provides an abnormality detection device for an engine oil pump. Hereinafter, the present invention will be explained in detail based on one embodiment of the accompanying drawings.

In FIG. 1, a cylinder 1 has a substantially cylindrical shape, and lids 2 and 3 are fixed by iron to both closed ends la and lb.

This cylindrical body 1 is formed of a synthetic resin member, for example, an acrylic pipe. Note that the joint body 1 is not limited to a synthetic resin pipe, but may also be a pipe made of a non-magnetic metal member such as aluminum. A connecting portion 2a protruding in the direction of the cylindrical body 1 is formed approximately in the center of one side of the lid body 2, and a hole 2c penetrating in the direction of the hammer is bored in the center of the connecting portion 2a. There is. The outer diameter of the end portion 2b of the connecting portion 2a is slightly thicker to prevent the connecting portion 2a from easily coming off when inserted into a rubber hose or the like (not shown). The lid body 3 is also formed similarly to the diamond body 2. These lids 2, 3, etc. are also integrally formed of a synthetic resin member, a non-magnetic metal member, etc., similarly to the above-mentioned cylindrical member 1. Inside the cylindrical body 1, an on-off valve 4 is arranged between the lid bodies 2 and 3 via a spring 5.

The on-off valve 4 has a cylindrical shape with a generally convex cross section, and the outer diameter of the front portion 4a is slightly smaller than the inner diameter of the cylindrical body 1.
A ring-shaped magnet 6 is arranged and fixed to the front portion 4a in a sandwich-like manner as shown in the figure. For the magnet 6, it is preferable to use an alnico-based magnetic member such as MK steel or NKS steel, which has good temperature characteristics.
Further, the on-off valve 4 is made of a light material such as cork. Note that the on-off valve 4 is not limited to being made of cork, but may be formed of, for example, synthetic resin with a hollow interior. The spring 5 has one closing side 5a inserted into the rear part 4b of the on-off valve 4, and the other opening side 5b in contact with the inner surface of the lid 3, so as to always press the on-off valve 4 toward the lid 2. Due to the pressing force of this spring 5, the opening/closing valve 4 has a surface 4c that is connected to the inner surface 2d of the lid body 2.
and closes the hole 2c. And this on-off valve 4
is a slight differential pressure △P (approximately 0.02~
The spring pressure of the spring 5 is set so that it moves in the directions of arrows A and A' at a rate of 0.05k9/ground). reed switch 7
is arranged at a predetermined external position on the lid body 2 side of the cylinder body 1,
It is arranged so that its longitudinal direction coincides with the axial directions of the cylinder 1.

One side lead portion 7a of this reed switch 7 is connected to a terminal T through a resistor R, and the other side lead portion 7a is connected to a terminal T through a resistor R.
It is grounded to b. This terminal T has a predetermined voltage of 10 V.
is applied. Further, an output terminal t is connected to an interconnection point B between the lead portion 7a and the resistor R. and,
This reed switch 7 is turned off when the surface 4c of the on-off valve 4 is in contact with the surface 2d of the lid body 2 as shown in FIG.
When the on-off valve 4 moves a predetermined distance in the direction of arrow A (FIG. 4), it is turned on. The distance traveled by the on-off valve 4 for turning on and off the reed switch 7 is a design issue. The connection part 2a of the lid body 2 is on the engine oil inflow side,
The connecting portion 3a of the lid 3 is on the outflow side.

In this way, an engine oil pump operation detector (hereinafter simply referred to as a detector) 9 is configured.

It goes without saying that the detector 9 is constructed in an airtight manner. As shown in FIG. 2, this detector 9 is arranged between the oil passage 15 between the oil feed pump 13 and the distributor 14 in the engine oil supply system of the two-stroke gasoline engine 16, and the connecting portion 2a is placed on the oil feed pump 13 side. Connecting part 3 to the pipe 15a of
a to the pipes 15b on the distributor 14 side, respectively. When the engine 16 is stopped, the oil feed pump 13 does not operate, and therefore engine oil is not pumped to the oil passage 15 side.

In this state, oil does not flow into the detector 9 from the connection part 2a of the detector 9, so the on-off valve 4 is pressed by the spring 5 as shown in FIG. It is in contact with the inner surface 2d, the reed switch 7 is turned off, and no signal is output from the terminal T2.
When the engine 16 is driven, the oil feed pump 13 starts operating.

The oil feed pump 13 operates at a predetermined period T in accordance with the rotation of the engine 16 to pump oil. The operating period T of this oil feed pump 13 is, for example, 1.32 during idling.
seconds, and at maximum rotation it is set to 0.197 seconds. The operating period T changes between 1.32 and 0.197 seconds depending on the engine rotation. Therefore, the engine oil is pumped in a pulsed manner as shown in FIG. 3 according to the operating period T of the oil pump 13, and flows into the detector 9 from the connecting portion 2a. Then, as shown in FIG. 4, this inflowing oil flows to the rear of the on-off valve 4 through the gap between the on-off valve 4 and the cylinder body 1 while causing the on-off valve 4 to undergo a pressure shift in the direction of arrow A. It flows out of the connection 3a and flows into the distributor 14 via the pipe 15b. Distributor 14
is for distributing oil to each cylinder of the engine, and the inflowing oil is sent to the engine 16 via a pipe 17.
A predetermined amount is distributed to each cylinder (not shown). When the on-off valve 4 is pushed in the direction of arrow A as shown in FIG. 4, the reed switch 7 is turned on.

When the operation of the oil feed pump 13 is stopped and the flow of oil is stopped, the on-off valve 4 is pressed in the direction of arrow A' by the spring 5, and the surface 4b comes into contact with the lid body 2, resulting in the state shown in FIG. As a result, the reed switch 7 is turned off. Open/close valve 4
operates as described above in accordance with the flow of oil in the oil passage 15, that is, the operation of the oil feed pump 13. Therefore, a pulse signal Ps with a period T is output from the output terminal L in response to the operation of the on-off valve 4. That is, a pulse signal with a period of 1.32 seconds is obtained during idling, and a pulse signal with a period of 0.197 seconds is obtained during maximum rotation. Of course, the period of this output pulse signal varies from 1.32 to 1.32 depending on the engine rotation.
It varies between 0.19 million sand. This pulse signal Ps is applied to a waveform shaping circuit 18 to be waveform-shaped as shown in FIG. 5, and then applied to a bandpass filter circuit 19. The band width of this bandpass filter circuit 19 varies from 1/1.32 to 1/1.32 depending on the operating period T of the oil pump 13.
It is set to 1'0.197 cycles. Therefore, when the oil feed pump 13 is operating normally, the engine 1
6, a pulse signal Ps with a period of 1.32 to 0.197 seconds, that is, a repetition frequency of 1/1.32 to 1'0.197 cycles is output, and this pulse signal Ps is passed through a bandpass filter. It passes through circuit 19 and is applied to comparator 20. The comparator 20 is for detecting the presence or absence of an input signal, and when an input signal is applied, the signal is 0, and when the input signal is not applied, the signal is 1.
is output and added to the alarm drive circuit 21. This drive circuit 2
1 outputs a drive signal S when the signal 1 is applied, and lights up, for example, an alarm lamp (not shown) of the alarm device 22 or operates a buzzer (not shown). Now, assume that the operating period T' of the oil feed pump 13 has become longer than 1.3 current sand for some reason.

The output terminal L outputs a pulse signal P's having a frequency corresponding to the operating period T' of the oil pump 13. However, this signal P's is filtered by the bandpass filter circuit 19.
, and no signal is applied to comparator 20'. Therefore, the drive circuit 21 outputs the signal S to light the alarm lamp of the alarm device 22 or operate the buzzer. The operator immediately stops the engine 16 upon sensing this alarm. Operation period T of oil feed pump 13
The same is true when, contrary to the above, the length becomes shorter than 0.19 million sand. In this way, an abnormality in the oil feed pump 13 can be detected immediately, and it is possible to prevent the engine 16 from running out of steam. Further, the drive signal S is applied to, for example, an automatic engine stop device (not shown), so that if the operation of the oil pump 13 becomes abnormal as described above, the engine is automatically stopped immediately. Good too.

Further, as shown in FIG. 6, a bandpass filter circuit 19
It is also possible to use the integrating circuit 23 instead, and in this case, a simple detection device can be constructed.

Furthermore, in this embodiment, a case has been described in which the detector 9 is connected to the oil passage 15 between the oil feed pump 13 and the distributor 14 as shown in FIG. 1, but the present invention is not limited to this.
As shown in FIG. 7, an oil passage 25 is provided between the distributor 14 and the oil tank 11.
, and the detector 9 may be connected to this oil passage 25. As explained above, according to the present invention, the structure is extremely simple, robust, and durable, and it is also small, lightweight, inexpensive, and extremely easy to install, and can be used against temperature changes over a wide range of engine compartments. It operates well even under adverse conditions such as severe vibrations, and has excellent effects such as being able to accurately and quickly detect abnormalities in the engine oil pump.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the engine oil pump operation detector according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the detector according to the present invention used in an engine oil supply system. Figure 3 is a diagram schematically showing the oil flow in the engine oil supply system shown in Figure 2.
The figure is an explanatory diagram of the operation of the detector shown in Fig. 1, Fig. 5 is a block diagram showing one embodiment of an alarm device using the detector of the present invention, and Fig. 6 shows another embodiment of the alarm device. Block Diagram,
FIG. 7 is a block diagram showing another embodiment of the mounting position of the detector according to the present invention to the engine oil supply system. 1... cylinder body, 2, 3... lid body, 4...
...Opening/closing valve, 5...Spring, 6...Magnet, 7...Reed switch, 13...Oil pump, 15,
I7, 34...Oil path, 14...Distributor, 1
6...Engine. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7

Claims (1)

[Claims] 1 A device for detecting an abnormality in an oil pump that pumps engine oil intermittently at a period corresponding to the rotational speed of the engine, which has an inlet at one end through which engine oil from the oil pump is introduced, and the other end. a sealed cylindrical body having an outlet for the oil; an on-off valve disposed within the cylindrical body via a spring, one side of which closes the inlet by a spring force and is movable in the axial direction of the cylindrical body; A magnet fixed to the valve, a reed switch disposed at a predetermined position outside the cylinder body and turned on and off according to the positional displacement of the magnet as the opening/closing valve shifts, and engine oil flowing in from the inlet. An abnormality detection device for an engine oil pump, comprising circuit means for detecting an abnormality in the oil pump based on the output frequency of the reed switch when the on-off valve is reciprocated.