JP2023131273A - oil circulation device - Google Patents

Abstract

To provide an oil circulation device capable of preventing the degradation of the sucking performance of a scavenging pump using oil supplied from an oil pump for pump priming while securing the sucking performance of the scavenging pump at starting an engine.SOLUTION: An oil circulation device 1 includes a switching valve 40 having a first port 401a communicated with a discharge port of an oil pump 31, a second port 401b communicated with a suction port of a scavenging pump 32, and a third port 401c for relieving oil. The switching valve 40 shuts off the communication of the first port 401a with the second port 401b and the third port 401c when an oil pressure to be supplied to the first port 401a is lower than a first predetermined pressure, communicates the first port 401a with the second port 401b when the oil pressure is approximately equal to the first predetermined pressure, and communicates the first port 401a with the third port 401c when the oil pressure is equal to or higher than a second predetermined pressure higher than the first predetermined pressure.SELECTED DRAWING: Figure 2

Description

The present invention relates to an oil circulation device.

Conventionally, for example, in an engine equipped with a turbocharger, in addition to an oil pan (main oil pan) placed at the bottom of the crankcase, an oil catch tank (turbo oil pan) is placed below the turbocharger. A well-known lubricating device (oil circulation device) uses a scavenge pump to suck up the oil collected in the oil catch tank after lubricating the turbocharger bearings, which are located lower than the oil pan, and return it to the oil pan, where it is stored. It is being

By the way, in such an oil circulation system, if an internal gear type pump is used as a scavenge pump, for example, by applying an oil film to the seal part to improve airtightness and sucking up oil, the engine may be left unused for a long period of time. If the oil inside the scavenge pump falls into the oil catch tank and there is no more oil inside the scavenge pump (that is, the inside of the scavenge pump is dry), then when starting the engine, the negative pressure must be applied. This may result in a situation where the oil cannot be sucked up.

Here, in Patent Document 1, lubricating oil (oil) is supplied in the order of turbo oil pan (oil catch tank), oil circulation pump (scavenge pump), main oil pan (oil pan), and feed pump (oil pump). In an engine lubrication system that allows oil to flow, a lubricating oil bypass pipe connects the oil pump's discharge port and the scavenge pump's suction port, and oil (priming water) is transferred from the oil pump side to the scavenge pump side during engine operation. ) has been disclosed to ensure oil is always present in the pump chamber of the scavenge pump to ensure the sealing performance of the sealing parts of the scavenge pump and the lubricity of each sliding part.

Japanese Patent Application Publication No. 2006-266235

As described above, according to the technology disclosed in Patent Document 1, the oil pump's discharge port side and the scavenge pump's suction port side are connected by a lubricating oil bypass pipe, and oil ( Since priming water is supplied, the sealing performance of the scavenge pump sealing parts and the lubricity of each sliding part are ensured. Therefore, even if the inside of the scavenge pump becomes dry due to long-term storage, it is possible to prevent oil from being unable to be sucked up when starting the engine afterwards.

However, in the technology of Patent Document 1 mentioned above, as the engine speed increases, the discharge amount of the oil pump increases and the oil flow rate of the lubricating oil bypass pipe increases, and the amount of inflow to the scavenge pump (the amount of priming water) As a result, the suction performance of the scavenge pump may decrease. Additionally, as a result, oil may overflow from the oil catch tank.

The present invention has been made to solve the above problems, and while ensuring the suction performance of the scavenge pump when starting the engine, it also prevents the deterioration of the suction performance of the scavenge pump due to oil supplied as priming water from the oil pump. It is an object of the present invention to provide an oil circulation device that can prevent the above.

An oil circulation device according to one aspect of the present invention includes an oil pump that pressurizes and discharges oil stored in an oil pan, a scavenge pump that pumps out oil collected in an oil catch tank and returns it to the oil pan, and an oil pump. A first port communicates with the discharge port of the scavenge pump, a second port communicates with the suction port of the scavenge pump, and a third port that relieves oil. A switching valve that selectively switches the communication state of the first port, and the switching valve closes the communication between the first port, the second port, and the third port when the oil pressure is less than a first predetermined pressure. When the oil pressure is substantially equal to the first predetermined pressure, the first port and the second port are connected to each other, and when the oil pressure is equal to or higher than the second predetermined pressure, which is higher than the first predetermined pressure, the first port is opened. and the third port are in communication with each other.

According to the present invention, it is possible to ensure the suction performance of the scavenge pump at the time of engine startup, and to prevent the deterioration of the suction performance of the scavenge pump due to oil supplied as priming water from the oil pump.

1 is a diagram schematically showing a lubrication system (oil flow) of an engine to which an oil circulation device according to an embodiment is applied. 1 is a diagram showing a configuration of main parts of an oil circulation device according to an embodiment. It is a figure showing the state of the switching valve in the oil circulation device concerning an embodiment at the time of shutoff. It is a figure which shows the state of the switching valve at the time of priming water supply (at the time of 2nd port communication) in the oil circulation device which concerns on embodiment. It is a figure which shows the state of the switching valve at the time of oil relief (at the time of 3rd port communication) in the oil circulation device based on embodiment.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In each figure, the same elements are given the same reference numerals and redundant explanations will be omitted.

First, the configuration of an oil circulation device 1 according to an embodiment will be described using FIGS. 1 and 2 together. FIG. 1 is a diagram schematically showing a lubrication system (oil flow) of an engine 10 to which an oil circulation device 1 is applied. FIG. 2 is a diagram showing the configuration of essential parts of the oil circulation device 1. As shown in FIG.

The oil circulation device 1 is applied to an engine 10 including a turbocharger 11, for example. Note that the turbocharger 11 is arranged at a position lower than the engine 10 main body (the oil level of an oil pan 21, which will be described later). Here, the engine 10 may be of any type, such as a horizontally opposed four-cylinder gasoline engine. The turbocharger 11 is a supercharger that is arranged between an intake passage and an exhaust passage and supercharges intake air to achieve high output and low fuel consumption. The turbocharger 11 includes a turbine provided in the exhaust passage and a compressor provided in the intake passage and connected to the turbine by a rotating shaft. compresses the air.

The oil circulation device 1 supplies oil (lubricating oil) to, for example, lubricating parts such as the valve mechanism and crankshaft of the engine 10, and the bearings of the turbocharger 11. Therefore, the oil circulation device 1 includes an oil pan 21 that stores oil, an oil pump 31 that sucks up the oil stored in the oil pan 21 through a strainer, raises the pressure, and discharges it, and a position lower than the oil pan 21. , and a scavenge pump 32 that pumps out the oil collected in the oil catch tank 22 and returns it to the oil pan 21.

As the oil pump 31, for example, a trochoid pump (internal gear pump) or the like is used. Oil pump 31 is driven by engine 10, for example. Similarly, as the scavenge pump 32, for example, a trochoid pump (internal gear pump) or the like is used. Scavenge pump 32 is also driven by engine 10.

For example, oil in an oil pan 21 provided at the bottom of the engine 10 (crankcase) is sucked up by an oil pump 31 and supplied to lubricating parts such as a valve mechanism of the engine 10. Then, the oil used for lubricating the lubricating parts of the engine 10 is dropped into the oil pan 21, collected, and temporarily stored.

On the other hand, a part of the oil used for lubricating the lubricating parts of the engine 10 (or a part of the oil discharged from the oil pump 31) is transferred to the bearings of the turbocharger 11 located at a lower position than the main body of the engine 10, etc. (lubricating part). The oil used for lubricating (and cooling) the turbocharger 11 is collected by dropping into an oil catch tank 22 disposed below the turbocharger 11. Thereafter, it is sucked up by the scavenge pump 32 and sent to the oil pan 21 through the oil path 54.

In particular, the oil circulation device 1 has a function of ensuring the suction performance of the scavenge pump 32 at the time of engine startup and preventing the deterioration of the suction performance of the scavenge pump 32 due to oil supplied as priming from the oil pump 31. There is. Therefore, the oil circulation device 1 includes a switching valve 40.

The switching valve 40 communicates with the discharge port of the oil pump 31, and has a first port 401a connected to a first oil passage 51 that supplies oil discharged from the oil pump 31, and a suction side (expansion side) of the scavenge pump 32. The second port 401b is connected to a second oil passage 52 that supplies oil as a priming water to the scavenge pump 32, and the third port 401c is connected to a third oil passage 53 that relieves oil. are doing. The switching valve 40 selectively switches the communication state of the first port 401a (first oil passage 51) depending on the oil pressure supplied to the first port 401a (pressure of oil discharged from the oil pump 31). .

More specifically, when the oil pressure is less than a first predetermined pressure, the switching valve 40 switches between the first port 401a (first oil passage 51), the second port 401b (second oil passage 52), and the third oil passage. Communication with the port 401c (third oil passage 53) is cut off (valve closed). On the other hand, when the oil pressure is substantially equal to the first predetermined pressure, the switching valve 40 connects the first port 401a (first oil passage 51) and the second port 401b (second oil passage 52). Then, oil as priming water is supplied to the scavenge pump 32. Furthermore, when the oil pressure is higher than a second predetermined pressure that is higher than the first predetermined pressure, the switching valve 40 switches between the first port 401a (first oil passage 51) and the third port 401c (third oil passage 53). communicate. Then, the supply of priming water to the scavenge pump 32 is stopped, and the oil is relieved. That is, the switching valve 40 also has a function as a relief valve (it can also function as a relief valve).

This will be explained in more detail below. The switching valve 40 has a valve case 401 formed, for example, in the shape of a cylinder with a bottom. A first port 401a, a second port 401b, and a third port 401c are formed in the valve case 401 along the axial direction. For example, the first port 401a is formed in a circular shape on one end surface (top surface) of the valve case 401 (or may be formed on the side surface). The second port 401b is formed in a circular shape on the side surface of the valve case 401. The third port 401c is formed in a circular shape on the side surface of the valve case 401 and at a position farther away than the second port 401b when viewed from the first port 401a.

A spool valve 402 formed in, for example, a cylindrical shape is housed inside the valve case 401 so as to be slidable in the axial direction. A through hole 402a, more specifically, a through hole 402a having an L-shaped cross section where the other end of the hole formed in the axial direction and the hole formed in the radial direction intersect is formed inside the spool valve 402. ing. One end of the hole formed in the axial direction communicates with the first port 401a (first oil passage 51), and the other end of the hole formed in the radial direction communicates with the communication destination (blocking, second port 401b (second oil passage 51)). The oil passage 52) and the third port 401c (third oil passage 53) can be switched.

One end surface (inner surface) of the valve case 401 and one end surface of the spool valve 402 define a hydraulic chamber 403 to which oil discharged from the oil pump 31 via the first port 401a is supplied.

A spool valve is arranged between the other end surface (inner surface) of the valve case 401 and the other end surface of the spool valve 402 in a direction that blocks communication between the first port 401a, the second port 401b, and the third port 401c. A biasing member 404 that applies biasing force to 402 is provided. As the biasing member 404, for example, a coil spring or the like is used. The biasing force of the biasing member (coil spring) 404 increases as it is compressed. That is, the biasing force at the position where communication of the first port 401a is blocked (the first position)<the biasing force at the position where the first port 401a and the second port 401b communicate with each other (the second position)<the first This is a biasing force at a position (third position) where the port 401a and the third port 401c communicate with each other.

The spool valve 402 slides in the axial direction depending on the force relationship (balance) between the pushing force of the hydraulic pressure of the hydraulic chamber 403 and the urging force of the urging member (coil spring) 404. More specifically, in the spool valve 402, the product of the oil pressure and the pressure-receiving area of the spool valve 402 (multiply value = pushing force) is the position where the first port 401a and the second port 401b communicate with each other (the second position). ), if the biasing force is less than the biasing force of the biasing member 404 when the spool valve 402 is located at Communication with the third port 401c (third oil passage 53) is cut off.

On the other hand, the spool valve 402 is such that the product (multiplication value = pushing force) of the oil pressure and the pressure receiving area of the spool valve 402 is such that the first port 401a and the second port 401b are in communication (second position). When the biasing force of the biasing member 404 is substantially equal to the biasing force when the biasing member 404 is positioned, it slides in the axial direction and communicates the first port 401a (hydraulic chamber 403) with the second port 401b. Therefore, oil as priming water is supplied to the scavenge pump 32.

In addition, the spool valve 402 is configured such that the product (multiply value = pushing force) of the oil pressure and the pressure receiving area of the spool valve 402 is located at a position (third position) where the first port 401a and the third port 401c communicate with each other. If the biasing force is equal to or greater than the biasing force of the biasing member 404 when 402 is positioned, it further slides in the axial direction and communicates the first port 401a (hydraulic chamber 403) with the third port 401c. Therefore, the supply of priming water to the scavenge pump 32 is stopped and oil is relieved.

Therefore, when the oil pressure becomes higher than the second predetermined pressure, the switching valve 40 changes the communication state of the first port 401a (first oil passage 51) from the blocked state to the communication state of the second port 401b (second oil passage 51). 52), and then transitions to a state of communication with the third port 401c (third oil passage 53). That is, the switching valve 40 supplies oil as priming water to the scavenge pump 32 in a transient state (during a transition).

Further, as described above, the switching valve 40 has a function as a relief valve that relieves oil when the oil pressure becomes equal to or higher than the second predetermined pressure. Therefore, the switching valve 40 can also be used as a conventionally used relief valve.

Here, the hole diameter of the through hole 402a, the opening area of the second port 401b, the urging force of the urging member (coil spring) 404, etc. are determined depending on the amount of oil as priming water required by the scavenge pump 32. In other words, it is set so that the required amount can be supplied. For example, when the oil temperature is about 40°C (warm-up mode) and the engine speed at startup is about 2000 rpm, the oil pressure increases to 6 to 7 K, so the biasing member of the switching valve (relief valve) 40 The (coil spring) 404 is set to open at about 5K (that is, set to open reliably), for example.

Next, the operation of the oil circulation device 1 will be explained with reference to FIGS. 3 to 5. FIG. 3 is a diagram showing the state of the switching valve (relief valve) 40 in the oil circulation device 1 at the time of shutoff. FIG. 4 is a diagram showing the state of the switching valve (relief valve) 40 in the oil circulation device 1 when priming water is supplied (when the second port 401b is in communication). FIG. 5 is a diagram showing the state of the switching valve (relief valve) 40 in the oil circulation device 1 during oil relief (when the third port 401c is in communication).

When the hydraulic pressure in the hydraulic chamber 403 is less than the first predetermined pressure, the product of the hydraulic pressure and the pressure-receiving area of the spool valve 402 (multiply value = pushing force) communicates the first port 401a and the second port 401b. Since the biasing force of the biasing member 404 is smaller than that when the spool valve 402 is located in the position (second position), as shown in FIG. , communication with the second port 401b (second oil passage 52) and third port 401c (third oil passage 53) is cut off (valve closed). Therefore, the supply of oil as a priming water to the scavenge pump 32 is stopped.

When the oil pressure becomes higher than the state in FIG. 3 and becomes substantially equal to the first predetermined pressure, the product (multiply value = pushing force) of the oil pressure and the pressure receiving area of the spool valve 402 is Since the biasing force of the biasing member 404 is approximately equal to the biasing force of the biasing member 404 when the spool valve 402 is located at a position (second position) where the spool valve 402 and the second port 401b communicate with each other, as shown in FIG. slides, and the first port 401a (first oil passage 51, hydraulic chamber 403) and second port 401b (second oil passage 52) are communicated with each other. Therefore, oil as priming water is supplied to the scavenge pump 32. Here, when the oil is left for a long time, the temperature of the oil is low and the viscosity is high, so when the engine is started after being left for a long time, the discharge pressure of the oil pump 31 becomes high (a high oil pressure higher than the first predetermined value), and as a priming water. of oil is supplied to the scavenge pump 32.

When the oil pressure becomes higher than the state shown in FIG. 4 and reaches a second predetermined pressure that is higher than the first predetermined pressure, the product of the oil pressure and the pressure receiving area of the spool valve 402 (multiply value = pushing force ) is greater than or equal to the biasing force of the biasing member 404 when the spool valve 402 is located at the position where the first port 401a and the third port 401c communicate with each other (third position), and as shown in FIG. The spool valve 402 slides, and the first port 401a (first oil passage 51, hydraulic chamber 403) and third port 401c (third oil passage 53) are communicated with each other. Therefore, the supply of oil as a priming water to the scavenge pump 32 is stopped, and the oil is relieved.

As described above in detail, according to the present embodiment, when the oil pressure in the oil pressure chamber 403 becomes approximately equal to the first predetermined pressure, the product of the oil pressure and the pressure receiving area of the spool valve 402 (multiply value = The pushing force) is approximately equal to the urging force of the urging member 404 when the spool valve 402 is located at the position (second position) where the first port 401a and the second port 401b communicate with each other. The first port 401a (first oil passage 51) and the second port 401b (second oil passage 52) are communicated with each other. Therefore, oil as priming water is supplied to the scavenge pump 32. Here, when the oil is left for a long time, the temperature of the oil is low and the viscosity is high, so when the engine is started after being left for a long time, the discharge pressure of the oil pump 31 becomes high (a high oil pressure higher than the first predetermined value), and as a priming water. of oil is supplied to the scavenge pump 32. Therefore, the suction performance of the scavenge pump 32 immediately after starting the engine can be ensured.

Further, according to the present embodiment, when the oil pressure becomes equal to or higher than the second predetermined pressure, which is higher than the first predetermined pressure, the product (multiply value = pushing force) of the oil pressure and the pressure receiving area of the spool valve 402 is The biasing force of the biasing member 404 is greater than or equal to the biasing force of the biasing member 404 when the spool valve 402 is located at a position where the first port 401a and the third port 401c communicate with each other (third position). 51, hydraulic chamber 403) and the third port 401c (third oil passage 53) are communicated with each other. Therefore, the supply of oil as a priming water to the scavenge pump 32 can be stopped, and the oil can be relieved.

Furthermore, according to the present embodiment, when the oil pressure is less than the first predetermined pressure, the product of the oil pressure and the pressure receiving area of the spool valve 402 (multiply value = pushing force) is The biasing force of the biasing member 404 is smaller than the biasing force of the biasing member 404 when the spool valve 402 is located at a position (second position) where the first port 401a (first oil passage 51) and the second Communication with the port 401b (second oil passage 52) and third port 401c (third oil passage 53) is cut off (valve closed). Therefore, when warm-up is completed and the oil temperature rises and the viscosity of the oil decreases, and the oil pressure becomes low, the supply of oil as priming water to the scavenge pump 32 is stopped, so the scavenge pump 32 It is possible to prevent the intake amount (discharge amount) from decreasing.

As a result, according to the present embodiment, when the inside of the scavenge pump 32 is in a dry state, oil is supplied as priming water (because it is not constantly supplied), so that the suction performance of the scavenge pump 32 at the time of starting the engine is improved. While ensuring this, it is possible to prevent the suction performance of the scavenge pump 32 from deteriorating due to the oil supplied as priming water from the oil pump 31.

Furthermore, according to the present embodiment, priming water is supplied to the scavenge pump 32 only immediately after the engine is started after being left unused (in a cold state). It is possible to reduce the friction (improve fuel efficiency) and downsize (reduce cost and weight) the oil pump 31 that supplies the oil.

According to the present embodiment, when the oil pressure becomes higher than the second predetermined pressure, the communication state of the first port 401a (first oil passage 51) changes from the blocked state to the communication state of the second port 401b (second oil passage 51). 52), and then transitions to a state of communication with the third port 401c (third oil passage 53). Therefore, oil can be supplied to the scavenge pump 32 as priming water in a transient state (during a transition). Then, when the oil pressure becomes higher, the supply of priming water can be stopped and the oil can be relieved.

According to this embodiment, the diameter of the through hole 402a, the opening area of the second port 401b, and the urging force of the urging member 404 are set according to the amount of oil as priming water required by the scavenge pump 32. Ru. Therefore, the flow rate of oil supplied as priming water and the priming water supply time (valve opening time) can be appropriately set, and the amount of priming water to be supplied can be appropriately set.

According to the present embodiment, the switching valve 40 can also be used as a relief valve that relieves oil when the oil pressure becomes equal to or higher than the second predetermined pressure (relief valve can be used), compared to a case where a dedicated switching valve is used. Therefore, it is superior (becomes advantageous) in terms of cost, weight, freedom of layout, etc.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above embodiments and can be modified in various ways. For example, the configuration (structure) of the switching valve (relief valve) 40 is not limited to the above embodiment, and other configurations (structures) may be used.

Further, in the above embodiment, a trochoid pump is used as the oil pump 31 and the scavenge pump 32, but instead of the trochoid pump, for example, an internal gear pump with other tooth shapes may be used.

1 Oil circulation device 10 Engine 11 Turbocharger 21 Oil pan 22 Oil catch tank 31 Oil pump 32 Scavenge pump 40 Switching valve (relief valve)
401 Valve case 401a 1st port 401b 2nd port 401c 3rd port 402 Spool valve 402a Through hole 403 Hydraulic chamber 404 Biasing member (coil spring)
51 1st oil passage 52 2nd oil passage 53 3rd oil passage

Claims (5)

An oil pump that pressurizes and discharges oil stored in an oil pan;
a scavenge pump that pumps out the oil collected in the oil catch tank and returns it to the oil pan;
The hydraulic pressure supplied to the first port includes a first port communicating with the discharge port of the oil pump, a second port communicating with the suction port of the scavenge pump, and a third port for relieving oil. a switching valve that selectively switches the communication state of the first port according to the
Equipped with
The switching valve is
When the oil pressure is less than a first predetermined pressure, communication between the first port, the second port, and the third port is cut off;
When the oil pressure is substantially equal to the first predetermined pressure, the first port and the second port are communicated;
The oil circulation device is characterized in that when the oil pressure is equal to or higher than a second predetermined pressure that is higher than the first predetermined pressure, the first port and the third port are communicated with each other. The switching valve changes the communication state of the first port from a blocked state to a communication state with the second port and then with the third port when the oil pressure becomes higher than the second predetermined pressure. 2. The oil circulation device according to claim 1, wherein the oil circulation device transitions to a communicating state. The switching valve is
a cylindrical valve case in which the first port, the second port, and the third port are formed along the axial direction;
a spool valve slidably housed in the valve case in the axial direction;
a hydraulic chamber defined by one end surface of the valve case and one end surface of the spool valve, and to which oil discharged from the oil pump is supplied through the first port;
The spool valve is disposed between the other end surface of the valve case and the other end surface of the spool valve, and is oriented in a direction that blocks communication between the first port, the second port, and the third port. a biasing member that applies a biasing force to the
has
The spool valve is
When the product of the oil pressure and the pressure receiving area of the spool valve is less than the urging force of the urging member when the spool valve is located at a position where the first port and the second port communicate with each other. cutting off communication between the first port, the second port, and the third port;
The product of the oil pressure and the pressure receiving area of the spool valve is approximately equal to the urging force of the urging member when the spool valve is located at a position where the first port and the second port communicate with each other. In this case, the first port and the second port are communicated,
When the product of the oil pressure and the pressure receiving area of the spool valve is greater than or equal to the urging force of the urging member when the spool valve is located at a position where the first port and the third port communicate with each other. The oil circulation device according to claim 1 or 2, wherein the first port and the third port communicate with each other. The oil according to claim 3, wherein the opening area of the second port and the urging force of the urging member are set according to the amount of oil as priming water required by the scavenge pump. Circulation device. The oil circulation device according to any one of claims 1 to 4, wherein the switching valve is a relief valve that relieves oil when the oil pressure becomes equal to or higher than the second predetermined pressure.

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