JPS5834261Y2 - Bypass valve for turbocharger lubrication in internal combustion engines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bypass valve that provides a supercharger lubrication circuit for an internal combustion engine.

Recently, in order to achieve high output, even small engines are equipped with superchargers, but since these small engines are rarely equipped with lubricating oil priming devices, when the engine suddenly starts up, There have been accidents where the metal of the supercharger, which rotates at a high speed of 100,000 revolutions per minute, has been seized due to lack of lubrication.

To prevent this, for example, as shown in Figures 1 and 2,
A bypass valve is provided.

That is, in FIG. 1, a branch pipe 6 is branched from the middle of the main lubrication circuit 5 (discharge side of the pump 2) from the oil pan 1, pump 2, filter 3, and cooler 4, and the supercharger bypass valve I is connected. Then, the supercharger 9 is lubricated via the pipe 8.

10 introduces lubricating oil from the discharge side of the cooler 4 into the bypass valve 7 when the lubricating oil pressure rises, switches the bypass valve I with the oil pressure, and thereafter supplies lubricating oil to the supercharger. It is a tube that performs.

Reference numeral 11 indicates various parts of the engine that require lubrication, 12 indicates a safety valve, 13 indicates a pressure regulating valve, and 14.15 indicates a bypass valve.

In the one shown in Fig. 1, oil is supplied to the pipes 6 and 8 by the difference in pressure loss between the filter 3 and the cooler 4, but if the capacity of the filter and cooler is increased, the pump 2
There is a possibility that the discharged oil does not flow to the turbocharger first, but instead flows to the filter and cooler.

The solution shown in Fig. 2 solves this problem.

That is, as shown in FIG. 2, the check valve 16 is provided immediately after the branch point of the branch pipe 6.

The amount of lubricating oil in the turbocharger is about 1/10 or less of the amount of oil fed into the engine, and since the pipes 6 and 8 are long and thin, a considerable pressure loss occurs, so the pressure loss in the filter and cooler is greater than this loss pressure. By inserting the check valve 16, the pipe 6
, 8 can be refueled.

However, the method shown in FIG. 2 has the following disadvantages.

(1) Although the pipe 6 is closed during operation, the pump 2
Since the entire amount of discharged oil passes through the check valve 16, pressure loss increases.

(2) The check valve resonates in a certain rotation speed range, producing noise.

(3) Pulsations occur in the hydraulic pressure, affecting other hydraulic equipment such as coolers and filters.

The present invention attempts to eliminate the above-mentioned drawbacks of the conventional example (the example shown in Fig. 2). It features a built-in check valve that is inserted into the engine, and a piston that switches the bypass circuit shuts off the check valve operation during normal engine operation.

Examples will be described below with reference to FIGS. 3 to 5.

FIG. 3 shows a lubricating oil circuit for an internal combustion engine using the bypass valve 20 of the present invention, and this circuit is the same as the conventional example shown in FIG.

FIG. 4-5 shows details of the bypass valve 20.

Figure 4 shows bypass valve 2 of an embodiment of the present invention before engine operation.
FIG.

The columnar valve casing 21 has a bottom wall at one end, the other end is sealed with a blind plug 25, and has a hollow part 23 inside, and has first openings that communicate with the hollow part 23 in order from the blind plug 25 side. 33
, the second opening 34, the third opening 28, and the fourth opening 29 are provided at different distances from the blind plug 25 so as not to overlap each other.

The first opening 33 communicates with the oil cooler 4,
The second opening 34 communicates with the supercharger 9, the third opening 28 communicates with the oil pump 2, and the fourth opening 29 communicates with the oil filter 3.
is in contact with.

A piston 22 is slidably housed in the hollow portion 23.

The first opening 33 side of this piston 22 is formed as a large-diameter head, and the fourth opening 29 side is formed as a small-diameter body portion with a smaller diameter.

The large diameter head is urged toward the first opening 33 by a spring 37 and comes into contact with the blind plug 25,
Further, inside the piston 22, the second piston 22 is in contact with the blind plug 25 by the spring 37.
A passage 30 connecting the opening 34 and the third opening 28 is bored, and communicates with the second opening 34 and the third opening 28 through communication holes 31 and 32, respectively.

The end of the small diameter body of this piston 22 is connected to the third opening 28.
space 2 between this end and the bottom wall.
4 is provided with a check valve 26 which is biased by a spring 36 and comes into contact with the valve seat 27.

This check valve 26 allows communication between the third opening 28 and the fourth opening 29 by moving in the same direction as the piston 22, and when the lubricating oil pressure in the third opening 28 increases beyond the set pressure. , as the button and piston 22 move, they move toward the bottom wall against the spring 36.

35 is a throttle hole provided in the valve casing 21 between the third opening 28 and the fourth opening 29, and 38 is an O-ring.

In the turbocharger bypass valve of this invention constructed as described above, when the engine is stopped or started, the piston 22 and the check valve 26 are each urged upward by the springs 37 and 36, as shown in FIG. is in a state of

Therefore, the oil discharged from the pump 2 flows as follows: third opening 28 → communication hole 32 → passage 30 → communication hole 31 → second opening 34, and passes through the pipe 8 shown in FIG. 3 to the supercharger 9 first. Lubricate.

Then, when the discharge oil pressure of the pump 2 increases and exceeds the set pressure of the check valve 26, the check valve 26 is pushed down, and a part of the discharge oil of the pump 2 flows from the third opening 28 to the fourth opening 29, and the filter 3, It lubricates the parts 11 of the engine that require lubrication through the cooler 4.

When the pressure rises, oil from the cooler 4 flows into the valve casing 21 through the first opening 33 and the histone 2
Acts on the 20 large diameter head.

As described above, the pressure receiving area of the head of this piston 22 is wider than that of the lower part, so the differential pressure causes the piston 22 to move toward the fourth opening 29, resulting in the state shown in FIG.

In the state shown in FIG. 5, the check valve 26 is pressed against the bottom wall side of the valve casing 21 by the piston 22, and as a result, the third opening 28 and the fourth opening 29 are connected to the check valve 26. communicate without being affected by
The first opening 33 and the second opening 34 also communicate with each other due to the movement of the piston 22.

After that, this state is maintained during normal operation of the engine, and the entire amount of oil discharged from the pump 2 is discharged from the third opening 28 and the fourth opening 2.
9, the lubricating oil is supplied from the filter 3 and the cooler 4 to the parts 11 that require lubrication, and the lubricating oil branched from the cooler 4 is supplied to the supercharger 9 from the pipe 10 → the first opening 33 → the second opening 34 → the pipe 8. It flows and is supplied like this.

Therefore, when the engine is started, the check valve 26 functions to ensure the amount of bypass oil to the supercharger.
During normal operation of the engine, the check valve 26 is pressed by the piston 22 and does not affect the flow path of the lubricating oil, so no pressure loss or vibration of the check valve occurs in the lubricating oil circuit.

In this way, in this invention, the check valve operates only when the engine is started, and does not cause any interference during normal operation.In addition, by incorporating the check valve into the bypass valve, it can be integrated into one body, and the engine The attachment to the holder has effects such as simplifying the work, and its practicality is extremely large.

[Brief explanation of the drawing]

Figures 1 and 2 are system diagrams of the conventional lubricating oil circuit, Figure 3 is the system diagram of the lubricating oil circuit of the present invention, and Figure 4 is a partially cutaway side view of the bypass valve of the present invention when the piston is raised ( FIG. 5 shows the piston when it is lowered (when the engine is in normal operating condition). DESCRIPTION OF SYMBOLS 1... Oil pan, 2... Pump, 3... Filter, 4... Cooler, 9... Supercharger, 11... Parts that require lubrication of the engine, 20... Bypass valve, 21...Casing, 22...Piston, 23...Hollow part, 2
6... Check valve, 27... Valve seat, 28, 29
, 33, 34... opening, 30... passage, 31, 32
...Communication hole, 35...Aperture.

Claims (1)

[Claims for Utility Model Registration] Lubricating oil is filtered by an oil pump. A bypass valve for lubrication of a turbocharger in an internal combustion engine, which is installed between an oil pump and an oil filter in the main lubrication circuit that supplies lubricating oil to each part of the engine via an oil cooler, and which supplies lubricating oil to the turbocharger. The valve casing of the bypass valve has a first opening communicating with the oil cooler, a second opening communicating with the supercharger, a third opening communicating with the oil pump, and a fourth opening communicating with the oil filter. Provide an opening,
Between the first opening and the fourth opening, there is a large diameter head on the first opening side, a small diameter body on the fourth opening side, and the first opening and the second opening are moved to the fourth opening side. A piston that connects the piston is biased toward the first opening and is slidably installed inside the piston, and in this biased state, a passage connecting the second opening and the third opening is bored inside the piston. A check valve is provided at the end of the body to connect the third opening and the fourth opening by moving in the same direction as the movement direction of the piston when the lubricating oil pressure in the third opening becomes high. Bypass valve for lubrication of supercharger of internal combustion engine.