JPH0893428A - Lubricating oil supplying apparatus for engine - Google Patents

Abstract

PURPOSE: To suppress an increase in consumption of an engine at the time of high rotary speed of the engine even if the capacity of an oil pump is made to be suitable for low speed. CONSTITUTION: A lubricating oil supplying apparatus is provided with a first oil pump 1 driven by an engine 2, a hydraulic motor 3 which works by a lubricating oil discharged out of the first oil pump 1, and a second oil pump 4 driven by the hydraulic motor 3. An engine lubrication route is composed by communicating the exhaust sides 4a, 3a of the second oil pump 4 and the hydraulic motor 3 with the engine 2 side through an oil supply route 5, the exhaust side 1a of the first oil pump 1 is communicated with the oil supply route 5 through a bypass route 6, a bypass route shutting valve 7 to open at the time when the rotary speed of the engine becomes a prescribed value or higher is installed in the bypass route 6, and the supply sides 1b of the first and the second oil pumps are respectively communicated with a supply route 10. Moreover, a reversing preventive system 11 such as a one-way clutch, etc., is installed in a driving shaft 31 of the hydraulic motor 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a lubricating oil supply device for supplying lubricating oil to an engine lubricating portion such as a sliding portion of a piston and a cylinder of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as this type of lubricating oil supply device, for example, one described in page 182 of the magazine "MOTOR FAN, September 1991" is known.
This is an oil pump consisting of two large and small Benz V12 gear pumps. When the discharge pressure of the pump exceeds a certain value by a relief valve, the discharge passage of the small pump is first made to communicate with the suction side to discharge the small pump. This is to reduce the consumption of horsepower by avoiding unnecessary pressurization of oil by setting the pressure to almost zero.

[0003]

However, the conventional lubricating oil supply device described above has a high efficiency in the oil pump.
Although two large and small gear pumps are used, and the relief valve properly escapes oil midway to avoid unnecessary pressurization to reduce the horsepower consumption, but the small pump is not in operation. However, since the rotation of the small pump does not stop, the horsepower consumed by the friction increases at the time of high speed rotation.

In view of the above point, the present invention suppresses an increase in horsepower consumption at high speed rotation by controlling the capacity of the oil pump to a capacity suitable for high speed rotation of the engine while ensuring a sufficient flow rate at low speed rotation of the engine. The purpose of the present invention is to provide a lubricating oil supply device for an engine.

[0005]

A lubricating oil supply apparatus for an engine according to the present invention comprises a first oil pump driven by the engine, a hydraulic motor operated by the lubricating oil discharged by the first oil pump, Second driven by the hydraulic motor
Of the second oil pump and the discharge side of the hydraulic motor are connected to the engine side via an oil supply passage to form an engine lubrication circuit, and the discharge side of the first oil pump is And a bypass passage cutoff valve that is opened when the oil pressure in the oil supply passage is equal to or higher than a predetermined value, and is connected to the oil supply passage through a bypass passage, and the oil of the first and second oil pumps is provided. The suction side was configured to communicate with the suction passages.

[0006]

When the engine rotates at a low speed, the bypass passage is shut off by the bypass passage cutoff valve. Therefore, the lubricating oil discharged from the first oil pump is supplied to the oil supply passage after operating the hydraulic motor. Further, due to the operation of this hydraulic motor, the second oil pump supplies the lubricating oil to the oil supply passage, so that the lubricating oil is supplied to the engine from both the first and second oil pumps. in this case,
Sufficient lubricating oil can be supplied to the engine by adjusting the capacity of the second oil pump to the amount of lubricating oil required when the engine rotates at low speed.

When the engine reaches a high speed, the bypass passage cutoff valve is opened to open the bypass passage, and the lubricating oil supplied by the first oil pump has a smaller resistance than the hydraulic motor side. Lubricant is supplied from the oil supply passage to the engine to lubricate the engine. At this time, since the hydraulic motor does not operate, the second oil pump also does not operate and is in a stopped state, so that the horsepower loss of the engine is prevented.

[0008]

EXAMPLE An example of the present invention will be described below with reference to FIG.

Reference numeral 1 is a first oil pump driven by the engine 2, 3 is a hydraulic motor operated by lubricating oil discharged from the first oil pump 1, and 4 is a second hydraulic motor driven by the hydraulic motor 3. The second oil pump 4 and the discharge sides 4a, 3a of the hydraulic motor 3 are connected to the engine 2 side via the oil supply passage 5 to form an engine lubrication circuit, and the first oil pump 1 discharge side 1a,
The bypass passage 6 is provided with a bypass passage shut-off valve 7 that opens when the oil pressure in the oil supply passage 5 is equal to or higher than a predetermined value, while communicating with the oil supply passage 5 via the bypass passage 6. The bypass passage cutoff valve 7 is provided in the pilot passage 8
Is connected to the oil supply passage 5 via a pilot pressure supplied from the oil supply passage 5 through the pilot passage 8 to open the valve. Since the lubricating oil pressure in the supply passage is low, the valve closing state is maintained by the spring reaction force in the passage shutoff valve 7, and when the rotation of the engine 2 increases, the pilot pressure increases to open the valve.

The oil suction sides 1b and 4b of the first and second oil pumps 1 and 4 are connected to the oil pan 9 at the other end of a suction passage 10 having one end open.

Reference numeral 11 denotes a reverse rotation preventing mechanism such as a one-way clutch, which prevents the hydraulic motor 3 from being operated from the second oil pump 4 side even if the second oil pump 4 is operated by receiving power from the hydraulic motor 3. It has become.

In the above embodiment, when the engine 2 rotates at a low speed, the bypass passage 6 is closed by the bypass passage cutoff valve 7, so that the oil discharged from the first oil pump 1 operates the hydraulic motor 3. After that, the oil is supplied to the oil supply passage 5, and by the operation of the hydraulic motor 3, the second oil pump 4 additionally supplies the lubricating oil to the oil supply passage 5 to lubricate the engine 2. In this case, by adjusting the capacity of the second oil pump 4 to the amount of lubricating oil that is insufficient by the first oil pump alone when the engine 2 rotates at low speed, sufficient lubricating oil can be supplied to the engine.

When the engine 2 reaches a high rotation speed, the bypass passage cutoff valve 7 is opened to open the bypass passage 6, and the lubricating oil supplied by the first oil pump 1 is supplied from the hydraulic motor 3 side. Lubricating oil is supplied to the oil supply passage 5 from the bypass passage 6 having a small resistance to lubricate the engine 2. At this time, since the hydraulic motor 3 does not operate, the second oil pump 4 also does not operate and is in a stopped state, thereby preventing the horsepower loss of the engine.

Further, at the time of high engine speed, the bypass passage 6
The lubricating oil supplied to the oil supply passage 5 side from the second side
Is also sent to the discharge side 4a side of the oil pump 4 and works to reverse the second oil pump 4, but the reverse rotation prevention mechanism 11 does not reverse the hydraulic motor 3.

[0015]

The lubricating oil supply apparatus for an engine according to the above-described structure is provided with a first oil pump driven by the engine, a hydraulic motor operated by the lubricating oil discharged by the first oil pump, and the hydraulic pressure. Second driven by motor
Of the second oil pump and the discharge side of the hydraulic motor are connected to the engine side via an oil supply passage to form an engine lubrication circuit, and the discharge side of the first oil pump is And a bypass passage cutoff valve that is opened when the oil pressure in the oil supply passage is equal to or higher than a predetermined value, and is connected to the oil supply passage through a bypass passage, and the oil of the first and second oil pumps is provided. Since the intake side is connected to each of the intake passages, the bypass passage is shut off by the bypass passage shutoff valve when the engine is rotating at a low speed. Therefore, the first oil pump operates the hydraulic motor. By the operation of the hydraulic motor, the second oil pump and the first oil pump supply the lubricating oil to the oil supply passage to lubricate the engine. In this case, the capacity of the second oil pump
Sufficient lubricating oil can be supplied to the engine by adapting to the insufficient amount of lubricating oil at low engine speed, and when the engine reaches high speed, the bypass passage cutoff valve opens and
The lubricating oil supplied from the first oil pump by opening the bypass passage is supplied to the oil supply passage through the bypass passage having less resistance than the hydraulic pump side, and lubricates the engine. At this time, since the hydraulic pump does not operate, the second oil pump also does not operate and is in a stopped state. Therefore, the capacity of the first oil pump can be selected to be suitable for the high speed rotation of the engine, thereby reducing the horsepower consumption at the high speed rotation of the engine. Therefore,
Even if the capacity of the first oil pump is adapted to the capacity at the time of engine high speed rotation, the lubricating oil supply amount is supplemented by the second oil pump at the time of engine low speed rotation, so there is no shortage of lubricating oil. Further, when the engine is rotating at high speed, the second oil pump is completely stopped, so that even if a sufficient pump capacity is secured at low engine speed, the horsepower consumption at high engine speed is not affected at all. Demonstrate excellent effects in practical use.

Further, according to the present invention, since the oil pump reverse rotation preventing mechanism for preventing the reverse flow of the lubricating oil to the suction passage by the second oil pump is provided, the second oil pump is stopped when the engine rotates at a high speed. However, this stop can prevent the backflow of the lubricating oil from the oil supply passage to the suction side through the second oil pump.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of a lubricating oil supply device in an engine according to the present invention.

[Explanation of symbols]

 1 1st Oil Pump 1a Discharge Side 1b Suction Side 2 Engine 3 Hydraulic Pump 3a Discharge Side 4 Second Hydraulic Pump 4a Discharge Side 4b Suction Side 5 Oil Supply Passage 6 Bypass Passage 7 Bypass Passage Shutoff Valve 8 Pilot Passage 9 Oil Pan 10 Inhalation passage

Claims (2)

[Claims] 1. A first oil pump driven by an engine, a hydraulic motor operated by lubricating oil discharged by the first oil pump, and a second oil pump driven by the hydraulic motor, The second oil pump and the discharge side of the hydraulic motor are connected to the engine side through an oil supply passage to form an engine lubrication circuit, and the discharge side of the first oil pump is supplied through the bypass passage to the oil supply. A bypass passage cutoff valve that opens when the oil pressure in the oil supply passage is equal to or higher than a predetermined value is provided in the bypass passage, and the oil suction sides of the first and second oil pumps are respectively communicated with the suction passage. A lubricating oil supply device for an engine, characterized in that 2. The lubricating oil supply device for an engine according to claim 1, further comprising an oil pump reverse rotation preventing mechanism for preventing a reverse flow of the lubricating oil into the suction passage by the second oil pump.