JPH0115844Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a lubricating device for an internal combustion engine, and particularly relates to an improvement for reducing driving loss of a lubricating oil supply device.

[Technical Background of the Invention] A lubricating system for an internal combustion engine supplies lubricating oil stored in a lubricating oil tank to each part of the engine using a single lubricating oil pump for lubrication. The lubricating oil supplied by this lubricating oil pump is adjusted to the required amount by a pressure regulating valve and then supplied to each part of the engine.

[Problems with the Background Art] By the way, the lubricating oil pump has a discharge rate set to ensure a sufficient amount when the engine is operating at low speed, so during high-speed operation, a considerable amount of lubricating oil is pumped through the pressure regulating valve. It is flowing back into the lubricating oil tank.
That is, as shown in FIG. 1, the discharge amount of the lubricating oil pump increases in proportion to the engine speed. For this reason, it is necessary to set the delivery amount of the lubricating oil pump to ensure the required amount when idling, etc. when the rotation speed is low, but in the high rotation speed range that is normally used, a considerable amount of lubrication is required by the hydraulic pressure adjustment valve. The oil will be returned to the lubricating oil tank.

In this way, since the lubricating oil that is wastedly returned to the lubricating oil tank is also discharged under pressure, the lubricating oil pump consumes extra driving force of the engine and causes an increase in energy loss.

[Purpose of invention]

Therefore, the purpose of this invention is to configure the second lubricating oil pump of the first and second lubricating oil pumps driven by the internal combustion engine to apply pressure only when necessary, so that the second lubricating oil pump can be used when no pressure is applied. An object of the present invention is to realize a lubricating device for an internal combustion engine that can reduce driving loss of the engine due to a reduction in the load of a lubricating oil pump and can reduce energy loss as a whole.

[Structure of the idea]

In order to achieve this object, this invention provides a lubricating system for an internal combustion engine, which includes a first lubricating oil pump and a second lubricating oil pump driven by the internal combustion engine, and the lubricating oil pump discharges from the second lubricating oil pump. When the discharge pressure of the first lubricating oil pump is above a predetermined pressure, the oil passage is communicated with a return oil passage that releases lubricating oil into the lubricating oil tank when the discharge pressure of the first lubricating oil pump is below a predetermined pressure. In some cases, the engine is characterized by a pressure regulating valve that communicates lubricating oil with a lubricating oil passage that supplies each part of the engine.

[Embodiment of the invention] Next, an embodiment of the invention will be described in detail based on the drawings. FIG. 2 is a schematic explanatory diagram of the lubricating device according to this invention. In the figure, 2 is a lubricating oil tank. According to this invention, the lubricating oil stored in the tank 2 is supplied to each part of the engine by two pumps, the first pump 4 and the second pump 6.
After lubrication, it flows back into tank 2 again. The discharge amounts of the first and second pumps 4 and 6 are set to be equivalent to the discharge amount of one conventional pump when combined.

The first and second pumps 4, 6 are provided in parallel with first oil passages 8-1, 8-2 and second oil passage 10-.
1 and 10-2, respectively. 1st
The first and second oil passages 8 - 1 and 10 - 1 on the suction side of the second pumps 4 and 6 communicate with the tank 2 . In addition, the first and second oil passages 8 on the discharge side
-2 and 10-2 are in communication with the pressure regulating valve 12. This pressure regulating valve 12 communicates with a lubricating oil passage 14 that supplies lubricating oil to various parts of the engine, and a return oil passage 16 that discharges lubricating oil to the tank 2.

Details of the pressure regulating valve 12 will be explained based on FIGS. 3 to 5. This pressure regulating valve 12 has two valve functions. The pressure regulating valve 12 introduces lubricating oil from the first pump 4 and causes it to flow through the lubricating oil path 14 at a predetermined pressure. A piston-shaped valve body 20 is slidably housed in the main body 18 of the pressure regulating valve 12 .
The valve body 20 has an adjustment spring 22 toward a portion where the first oil passage 8-2 on the discharge side and the lubricating oil passage 14 communicate with each other.
It is being oppressed by The adjustment spring 22 moves the valve body 20, which receives the oil pressure of the first oil passage 8-2 on the discharge side, back and forth to a predetermined position according to the pressure. By this forward and backward movement, the valve body 20 opens and closes the return hole 24 communicating with the return oil passage 16, and allows lubricating oil at a predetermined pressure to flow through the lubricating oil passage 14. That is, when the oil pressure in the first oil passage 8-2 on the discharge side is higher than a predetermined pressure, the valve body 20 moves back to open the return hole 24 as shown in FIG. A portion of is discharged into tank 2. When the pressure decreases, the valve body 20 moves forward and closes the return hole 24, allowing the entire amount of lubricating oil from the first pump 4 to flow through the lubricating oil passage 16, thereby preventing a drop in oil pressure and ensuring the required amount.

The entire amount of lubricating oil in the second oil passage 10 - 2 on the discharge side communicating with the main body 18 of the pressure regulating valve 12 is released or distributed through an oil passage provided in the valve body 20 . A groove-shaped discharge path 26 is provided on the surface of the valve body 20 in the circumferential direction. As shown in FIGS. 4 and 5, when the oil pressure on the lubricating oil passage 14 side is higher than a predetermined pressure and the valve body 20 is retracted, the discharge passage 26 is connected to the second oil passage 10-2 on the discharge side and the return hole. It is located on the surface of the valve body 20 so as to communicate with the valve body 24. In addition, the valve body 20
is provided with an introduction passage 28 communicating with the second oil passage 10-2 on the discharge side and an outflow hole 30 communicating with the lubricating oil passage 14. The introduction passage 28 and the outflow hole 30 communicate with each other through a communication hole 32 within the valve body 20, and constitute an oil passage through which the lubricating oil of the second pump 6 flows into the lubricating oil passage 14. Further, the introduction passage 28 is arranged so that when the introduction passage 28 is in communication with the second oil passage 10-2 on the discharge side, the discharge passage 26 is in a non-communication state.
The communication positions of the discharge passage and the discharge passage 26 with respect to the second oil passage 10-2 on the discharge side are set to be opposite to each other.

A spring 36 is provided in the communication hole 32 to close the ball valve 34.
to suppress it. This closing spring 36 is connected to the first
When the oil pressure in the oil passage 8-2 falls below a predetermined pressure and the valve body 20 is stopped at the position shown in FIG. The lubricating oil passage 14 is opened and allowed to flow to the lubricating oil passage 14.

Therefore, the valve body 20 is connected to the first oil passage 8-2 on the discharge side.
When the oil pressure of
Since the lubricating oil is released into the tank 2, no pressure is applied to the second pump 6. When the pressure is below the specified level,
The valve body 20 communicates the second oil passage 10-2 on the discharge side with the lubricating oil passage 14, and allows the lubricating oil of the second pump 6 to flow therethrough. Therefore, when the amount of lubricating oil is insufficient only in the first pump 4, the lubricating oil from the second pump 6 is supplied.

Next, the operation of this invention will be explained.

When the first and second pumps 4, 6 are driven by an internal combustion engine (not shown), the lubricating oil in the tank 2 flows through the first and second oil passages 8-1, 8-2, 10-1, 1.
0-2 and reaches the pressure regulating valve 12.

When the oil pressure in the first oil passage 8 - 2 on the discharge side is maintained at approximately a predetermined pressure, only the lubricating oil from the first pump 4 is supplied to the lubricating oil passage 14 . As shown in FIG. 5, when the oil pressure in the first oil passage 8-2 on the discharge side becomes higher than a predetermined pressure, the valve body 20 moves back and opens the return hole 24. As a result, the first pump 4
A portion of the lubricating oil is discharged from the return hole 24 to the tank 2 via the return oil path 16, reducing the pressure.
When the pressure decreases, the valve body 20 is advanced by the adjustment spring 22 as shown in FIG. 4 to close the return hole 24 and prevent the pressure from decreasing. Therefore, the entire amount of lubricating oil from the first pump 4 flows through the lubricating oil path 14 to ensure the required amount.

At this time, since the second oil passage 10-2 on the discharge side communicates with the return hole 24 via the discharge passage 26, the second oil passage 10-2 on the discharge side communicates with the return hole 24 through the discharge passage 26. The entire amount of lubricating oil has been discharged into tank 2. Therefore, the pressure of the first oil passage 8-2 on the discharge side does not act on the second pump 6, and the load is small, so that the driving loss of the engine can be reduced. Furthermore, since there is no energy loss in the second pump 6, energy loss can be reduced as a whole.

When the oil pressure in the fourth oil passage 8-2 on the discharge side becomes lower than a predetermined pressure, the valve body 20 moves further forward and stops at the position shown in FIG. 3. When the valve body 20 stops, the discharge path 26 is out of communication with the second passage 8-2 on the discharge side, and the introduction path 28 is in communication. Release path 2
6 is closed, the oil pressure in the second oil passage 10 increases, so
The lubricating oil pushes open the ball valve 34, flows from the communication hole 32 to the outflow hole 30, and flows out into the lubricating oil path 14. Therefore, the lubricating oil supplied from the first pump 4 and the second pump 6 prevents the pressure from decreasing too much, and a sufficient amount of lubricating oil can be ensured.

When the pressure in the first oil passage 8-2 on the discharge side is restored,
The valve body 20 is retracted to the state shown in FIG. 4, and the lubricating oil supplied by the second pump 6 is released into the tank 2. As mentioned above, the drive loss of the second pump 6 is reduced and energy loss is reduced. It disappears. Therefore, energy loss can be reduced as a whole.

[Effect of idea]

As described above, according to this invention, the discharge pressure of the first lubricating oil pump is maintained at a predetermined level in the second lubricating oil pump of the first and second lubricating oil pumps driven by the internal combustion engine, such as during idling at a low rotation speed. The configuration is such that the pressure on the discharge side is applied only when the pressure drops below and lubricating oil needs to be supplied from the second lubricating oil pump, so when driving at medium or high speeds in a high rotation speed range, the second lubricating oil pump is activated. There is no pressure on the discharge side. In this way, the discharge side pressure is not applied to the second lubricating oil pump in the high rotational speed range, so the load on the second lubricating oil pump in the high rotational speed range can be reduced. The driving loss of the engine in the region can be reduced and energy loss can be eliminated. Therefore, overall,
Energy loss of the internal combustion engine can be reduced.

[Brief explanation of drawings]

FIG. 1 is a graph showing the relationship between the delivery amount and supply amount of the lubricating oil pump with respect to the engine speed.
2 to 5 show an embodiment of this invention, with FIG. 2 being a schematic explanatory diagram of a lubricating device, and FIGS. 3 to 5 being sectional views showing the operating state of a pressure regulating valve, respectively. In the figure, 2 is a lubricating oil tank, 4 is a first pump, 6 is a second pump, 12 is a pressure regulating valve, 14
20 is a lubricating oil path, 20 is a valve body, 24 is a return hole, 26 is a discharge path, 32 is a communication hole, and 34 is a ball valve.

Claims (1)

[Scope of utility model registration request] In a lubricating device for an internal combustion engine, a first lubricating oil pump and a second lubricating oil pump driven by the internal combustion engine are provided, and a lubricating oil path discharged from the second lubricating oil pump is connected to a discharge lubricating oil path of the first lubricating oil pump. When the pressure is above a predetermined pressure, the lubricating oil is communicated with a return oil passage that discharges the lubricating oil into the lubricating oil tank, and when the discharge pressure of the first lubricating oil pump is below the predetermined pressure, the lubricating oil is supplied to each part of the engine. A lubricating device for an internal combustion engine, comprising a pressure regulating valve communicating with an oil passage.