JP3216530B2 - Engine lubricating oil recirculation system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating oil recirculation system for an engine, and more particularly, to a lubricating oil circulation passage provided with a temperature-sensitive control valve, and by selectively switching a lubricating oil passage between an oil cooler and a bypass passage. The present invention relates to a lubricating oil recirculation device for an engine that allows oil to flow.

[0002]

2. Description of the Related Art Generally, in a lubricating oil recirculation system for an engine, an oil cooler is provided on a lubricating oil circulation passage in order to radiate the lubricating oil when the engine is driven, and the lubricating oil is excessively heated by the oil cooler. To prevent them from doing so. Moreover, it is desirable to temporarily stop the heat release of the lubricating oil by the oil cooler in order to promote warm-up at the time of starting the engine at a low temperature or the like. It is configured so that oil can be bypassed. In this case, a temperature-sensitive bypass valve that selectively opens and closes both passages is provided at a branch point between a main passage provided with an oil cooler and a bypass passage arranged in parallel with the main passage.

This temperature-sensitive bypass valve has wax pellets forming a temperature-sensitive part, and converts the temperature expansion / contraction action into a projecting and retracting motion of a piston partially intruding into the temperature-sensitive part, and interlocks with the piston. The valve body selectively opens and closes the main passage and the bypass passage. For example, FIG. 9 shows a branch portion 2 of a lubricating oil circulation system of an engine in which a bypass passage 6 is juxtaposed to a part of the main passage 1. The branch portion 2 is formed in a housing 3 on the engine body side (not shown), and a temperature-sensitive bypass valve V is provided here. The main passage 1 communicates with the oil cooler 5 through the branch 2 from the hydraulic pump 4 to an oil gallery (not shown) on the engine body side, while the bypass passage 6 connects the main passage 1 with the branch 2.
, And reaches a junction 2 ′ (not shown) downstream of the oil cooler 5. The temperature-sensitive bypass valve V provided in the branch portion 2 includes a substantially cylindrical casing 7, a cylindrical valve 8 slidably fitted in the casing, and a temperature-sensitive drive connected to the cylindrical valve 8. A part 9.

Here, the lower end of the temperature-sensitive drive section 901 is in contact with the lower wall 301 in the housing 3 and the upper end is supported by the boss-shaped frame 701 on the casing 7 side. The temperature-sensitive drive unit 9 couples the tip of a piston 902 projecting upward (in FIG. 9) to the cylindrical valve 8. When the temperature-sensitive bypass valve V comes into contact with the low-temperature lubricating oil, the cylindrical valve 8 is held at the low-temperature position P1 indicated by a solid line. After passing through the boss-shaped frame portion 701 and the cylindrical valve 8, the casing 7
Can flow through the bypass passage 6 through the bypass opening 702 of
Heat release of lubricating oil can be suppressed to promote warm-up. On the other hand, the temperature sensing part 9
When 01 comes into contact with the high-temperature lubricating oil, the cylindrical valve 8 is held at the high-temperature position P2. At this time, after the lubricating oil passes through the temperature-sensitive portion 901, the main passage opening 7
The fluid can flow to the oil cooler 5 of the main passage 1 via the valve 03, and excessive temperature rise can be prevented.

Japanese Utility Model Laid-Open Publication No. 62-11287 discloses a temperature-sensitive control valve substantially similar to that shown in FIG. In this case, the main passage and the bypass passage extend in parallel downstream of the temperature-sensitive control valve, and the temperature-sensitive control valve is configured to selectively supply the lubricating oil to one of the two passages. In particular, when the bypass passage is clogged and the lubricating oil does not flow, the gate valve receiving the hydraulic pressure in the bypass passage opens to release high-pressure oil in the bypass passage to the main passage side, thereby preventing damage to the engine and the like.

[0006]

By the way, the temperature-sensitive bypass valve V shown in FIG.
In the temperature-sensitive control valve disclosed in Japanese Patent Application Laid-Open Publication No. H10-209, a cylindrical valve that switches between a main passage and a bypass passage is driven by a temperature-sensitive drive unit. For this reason, when the temperature-sensitive drive unit breaks down and, for example, the wax contained in the temperature-sensitive drive unit flows out, the protruding and retreating motion of the piston of the temperature-sensitive drive unit stops. Like the temperature-sensitive bypass valve V shown,
The tubular valve 8 stops at the low temperature position P1. Then, the main passage 1 remains closed, and the lubricating oil does not flow to the oil cooler 5 after the engine is warmed up, and the oil temperature rises abnormally. As a result, the viscosity of the lubricating oil decreases, lubrication of each sliding part such as a piston communicating with the oil gallery inside the engine is not properly performed, and seizure occurs. Such a problem occurs.

An object of the present invention is to avoid a situation in which lubricating oil cannot flow to the oil cooler side due to a failure of the temperature-sensitive control valve, and to prevent a failure of the engine body due to seizure inside the engine.

[0008]

In order to achieve the above-mentioned object, the present invention provides an oil cooler provided in the main passage in the middle of the main passage connecting the oil pump and the oil supply section in the engine. And a bypass passage for flowing the lubricating oil is arranged in parallel, and a temperature-sensitive control valve is disposed at one of a branch portion and a junction of the two passages. The switching drive source switches and drives the partition according to
In the lubricating oil recirculation device for an engine in which the partition wall selectively allows the lubricating oil to flow through the bypass passage or the main passage, the lubricating oil is mounted on the partition wall and the lubricating oil has a high temperature of a predetermined value or more. And a relief valve for automatically opening a portion corresponding to the main passage when the pressure is detected.

Therefore, a temperature-sensitive control valve is provided at one of a branch portion and a junction portion of the main passage having the oil cooler and the bypass passage, and the partition wall is driven by the drive source for switching the temperature-sensitive control valve. The partition wall allows the lubricating oil to flow selectively to the bypass passage or the main passage. In addition, when the lubricating oil has a high temperature equal to or higher than a predetermined value, the relief valve mounted on the partition automatically opens a portion corresponding to the main passage, thereby opening the main passage. As described above, when the lubricating oil has a high temperature equal to or higher than the predetermined value, the relief valve opens the main passage and guides the lubricating oil to the oil cooler to lower the oil temperature.

According to a second aspect of the present invention, in the first aspect of the present invention, the relief valve is made of a shape memory material. Therefore, for the relief valve made of a shape memory material, the shape for opening the portion corresponding to the main passage at a high temperature equal to or higher than a predetermined value is stored, and the shape for closing the opening at a low temperature is stored. A relief valve mounted on the main passage surely opens and closes the main passage according to the temperature of the lubricating oil.

According to a third aspect of the present invention, in the lubricating oil recirculation system for an engine according to the first aspect, the relief valve is formed of a bimetal. Accordingly, the relief valve made of a bimetal is displaced so as to open a portion corresponding to the main passage at a high temperature equal to or higher than a predetermined value, and is displaced so as to close the opening at a low temperature, so that the relief valve mounted on the partition wall is lubricated. The main passage is reliably opened and closed according to the oil temperature.

[0012]

FIG. 1 shows a lubricating oil recirculation device for an engine to which the present invention is applied. The lubricating oil recirculation system of an engine is mounted to a lubricating oil circulation O _F of the engine shown in FIG. 5, the oil gallery 11 of the oil pump 10 and the engine the oil supply portion in the lubricating oil circulation O _F
Is provided at a branch portion 13 in the middle of the main passage 12 connecting the two.

[0013] Here, the lubricating oil circulation system O _F is mounted to the engine 14 mounted on a vehicle, not shown, which is the oil reservoir 15 which is deployed in the lower portion of the engine 14, an oil pump 10 driven by the engine , A main passage 12 which is a discharge passage of the oil pump, and an oil cooler 1 on the main passage 12.
7, and an oil filter 18 disposed on the main passage 12 and disposed between the oil cooler 17 and the oil gallery 11 in the engine 14. In addition, a branch 13 is provided between the upstream side and the downstream side of the oil cooler 17 on the main passage 12.
Is formed, and an oil cooler 17 is provided between the two portions.
Is formed, and a bypass passage 19 for flowing the lubricating oil is formed. The branch portion 13 and the merging portion 16 and a part of the main passage 12 facing the branch portion 13 and the merging portion 16
41 (see FIG. 1).

As shown in FIG. 1, the branch portion 13 has a cylindrical valve chamber 131 in which the temperature-sensitive control valve 20 is provided.
In the valve chamber 131, an upstream opening 21 communicating with the oil pump 10 side, a main passage side opening 22 continuing to the oil cooler 17 side, and a bypass side opening 23 continuing to the bypass passage 19 side are formed. Here, the temperature-sensitive control valve 20 has a substantially cylindrical casing 24 that is immovably fitted to an upper portion (in FIG. 1) of the valve chamber 131, and slides in the direction of the center line L in this casing. It comprises a tubular valve 25 fitted freely, and a temperature-sensitive drive section 26 connected to the tubular valve 25.

The casing 24 has an upper annular projection 241 formed at an intermediate portion in a longitudinal direction thereof, a lower annular projection 242 formed at a lower portion thereof, and a boss-shaped frame portion 243 integrally formed below the lower annular projection 242. . Here, the upper annular projection 241 isolates the main passage opening 22 and the bypass opening 23 provided on the housing 141 side, and the lower annular projection 242 isolates the main passage opening 22 and the upstream opening 21. The casing 2
4 has a bypass hole 244 communicating with the bypass side opening 23 in a side wall between the upper annular protrusion 241 and the upper end, and a main passage side in a side wall between the upper annular protrusion 241 and the lower annular protrusion 242. A main passage hole 245 communicating with the opening 22 is formed.

The cylindrical valve 25 is slidably fitted to the inner peripheral wall of the casing 24, and has a cylindrical partition wall 251, a bottom frame 252 forming a bottom, and a plurality of openings 253 formed in the partition wall 251. In particular, a relief valve 28 is attached to the inner chamber of the cylindrical valve 25. The boss-shaped frame 2
Through holes are formed in the base frame 43 and the bottom frame 252, respectively, so that the lubricating oil can flow.

The relief valve 28 is connected to the opening 25 of the partition wall 251.
3 is provided so as to be normally closed. That is, as shown in FIGS. 3A and 3B and FIGS. 4A and 4B, the relief valve 28 is a curved long plate having a helical shape in plan view and formed of a shape memory material. Is done. This relief valve 28 is used for the partition wall 2.
A base end is buried and supported by the inner peripheral wall of 51, and another curved portion 281 extending from the base end to the inside of the relief valve 28 extends in a spring-like manner. The curved portion 281 has a width b that is larger than the vertical width of the opening 253, so that the curved portion 281 can open and close the three openings 253 corresponding to the main passage-side opening 22.

The shape memory material forming the relief valve 28 is as follows.
When the oil temperature, which is the ambient temperature, is detected, the opening 253 stored in advance is stored if the oil temperature is a predetermined high temperature, and the opening is closed at a low temperature.
That is, the relief valve 28 has a predetermined high temperature (for example, 115 ° C.) that is equal to or higher than the driving temperature (for example, 110 ° C.) of the temperature-sensitive driving unit 26.
° C), the bending portion 2 is detected as shown in FIG.
81 is stored so as to maintain the vine winding shape.
The opening 253 can be opened. On the other hand, when the temperature of the relief valve 28 falls below a predetermined high temperature, as shown in FIG.
81 is displaced in a loop to close the opening 253.

The shape of the relief valve 28 is simplified, so that the relief valve 28 can be easily housed in the inner chamber of the cylindrical valve 25, and the operation of mounting the relief valve is also facilitated, so that the cost can be reduced. Temperature-sensitive drive unit 26 connected to cylindrical valve 25
Is a piston 262 integrally connected to the bottom frame 252 of the cylindrical valve 25, and a temperature sensing portion 2 that accommodates one end of the piston.
61. The lower end of the temperature sensing part 261 abuts against the bottom wall 132 of the valve chamber 131, and the upper end of the neck surrounding the piston 262 is supported by the boss-shaped frame part 243.

The temperature sensing part 261 is of a well-known wax pellet type. When the oil temperature forming the ambient temperature is at room temperature, the piston 262 is retracted (the state shown by a solid line in FIG. 1). 25 at the low temperature position P1,
The bypass hole 244 is opened. On the other hand, when the oil temperature reaches the opening temperature (for example, 110 ° C.), the internal wax expands,
The piston 262 is protruded to operate (the state shown by the solid line in FIG. 2).
At this time, the cylindrical valve 25 is held at the high temperature position P2, and the main passage hole 245 is opened. The cylindrical valve 25
A return spring 29 is provided in the inner chamber of the, and assists the operation of returning the cylindrical valve 25 to the low temperature position P1.
The steady-state operation of such a lubricating oil recirculation device for an engine will be described.

When the engine is in cold start, FIG.
As shown in FIG. 3, the low-temperature lubricating oil discharged from the oil pump reaches the temperature sensing portion 261 in the valve chamber 131 via the main passage 12. At this time, the temperature-sensitive drive unit 26 detects the low temperature, holds the cylindrical valve 25 at the low-temperature position P1 (see FIG. 1), opens the bypass hole 244, and closes the main passage hole 245. In this case, as shown in FIG.
Is kept closed. Therefore, the lubricating oil flows into the bypass passage 19 through the boss-shaped frame portion 243, the bottom frame 25, the bypass hole 244, and the bypass-side opening 23. For this reason, the lubricating oil can bypass the oil cooler 17 at the time of the low temperature start, and can reach the oil gallery 11 via the oil filter 18 to lubricate the lubricating portion in the engine. In this case, the engine warm-up can be promoted.

On the other hand, when the warm-up of the engine is completed,
As shown in FIGS. 2 and 3, the high-temperature lubricating oil discharged from the oil pump reaches the temperature sensing portion 261 in the valve chamber 131. At this time, the temperature-sensitive drive unit 26 detects a high temperature (for example, 110 ° C.) and returns the piston 261 and the cylindrical valve 25 to the return spring 29.
Projecting to the high-temperature position P2 (see FIG. 2) against the spring force of (2), the bypass hole 244 is closed, and the main passage hole 245 is opened. Also in this case, as shown in FIG.
8 is held with the opening 253 closed.

Therefore, when the warm-up is completed, the lubricating oil flows to the oil cooler 17 in the main passage 12 through the boss-shaped frame portion 243 and the main passage hole 245. Therefore, when the warm-up is completed, the temperature of the lubricating oil is radiated by the oil cooler 17, and an excessive rise in the oil temperature can be suppressed.

As described above, the lubricating oil recirculation system of the engine operates in a steady state, but the temperature-sensitive control valve 20 breaks down due to deterioration over time or the like. It is assumed that the cylindrical valve 25 is deactivated at the low temperature position P1. In this case, even if the temperature of the lubricating oil becomes high due to the completion of the warm-up of the engine, the temperature-sensitive drive unit 26 is not operated, so that the cylindrical valve 25 closes the main passage hole 244 and keeps the bypass hole 244 open. Thus, the lubricating oil bypasses the oil cooler 17.

Here, when the oil temperature continues to rise further from the drive temperature (for example, 110.degree. C.) of the temperature-sensitive drive unit 26 and reaches a predetermined high temperature (for example, 115.degree. C.), the bending portion 281 of the relief valve 28 is moved to the position shown in FIG. 4 (b) is displaced from the loop shape shown in FIG. 4 (b), the opening 253 is opened, and the lubricating oil flows to the oil cooler 17 in the main passage 12.

As described above, even if the temperature-sensitive drive unit 26 fails,
The relief valve 28 can open the main passage hole 244 and the main passage 1
The lubricating oil can be radiated by the second oil cooler 17, and the lubricating oil can be reliably prevented from further rising above a predetermined high temperature. For this reason, it is possible to avoid a decrease in viscosity due to an excessively high temperature of the lubricating oil, to properly lubricate each sliding portion such as a piston inside the engine, to avoid a failure of the engine body, and to prevent a decrease in durability. . Further, even when the temperature-sensitive drive unit 26 is not malfunctioning, the boss-shaped frame portion 243, which is a normal oil passage,
Oil flows from the opening 253 in addition to the cylindrical valve 25 and the main passage hole 245, and the pressure loss of the lubricating oil can be reduced.

[0027] In the lubricating oil recirculation system of the engine 1, but the temperature sensitive control valve 20 has been deployed in the bifurcation 13 in the lubricating oil circulation system O _F, instead of this, the two-dot chain line in FIG. 5 As shown by, a temperature-sensitive control valve 20a may be provided at the junction 16. Here, the temperature-sensitive control valve 20a is the same as the temperature-sensitive control valve 20 in FIG.
As compared with the above, since the relief valve 28a attached to the opening 253 of the cylindrical valve 25 is formed in the same manner except that the relief valve 28a is different, the same reference numerals are given to the same members, and the repeated description is omitted. As shown in FIG. 6, the confluence part 16 is a cylindrical valve chamber 16.
1 is provided with a temperature-sensitive control valve 20a. The valve chamber 161 has a main passage side opening 22 communicating with the oil cooler 17 on the main passage 12 side, a bypass side opening 23 following the bypass passage 19, and a downstream outlet 31 communicating with the oil filter 18 and the oil gallery 11 side. It is formed.

Here, the cylindrical valve 2 of the temperature-sensitive control valve 20a
5 is provided with a relief valve 28a capable of opening the opening 253, as shown in FIGS. The partition wall 251 of the cylindrical valve 25 is provided with three openings 253 at substantially equal intervals in the circumferential direction thereof, and a curved plate-shaped relief valve 28a is opposed to each of the three openings 253.
One end of each relief valve 28a is embedded and supported in a partition wall 251 near one end of each opening 253, and the other curved plate portion is formed so as to close each opening 253. In addition, each relief valve 28 a is provided at a position facing the main passage hole 245 of the casing 24 and not interfering with the upper and lower opening ends of the main passage hole 245.

Such a relief valve 28a is also made of a shape memory material, and operates at a temperature (for example, 110 ° C.) of the temperature-sensitive drive unit 26.
When a predetermined high temperature (e.g., 115 [deg.] C.) or higher is detected, a shape for opening the opening 253 is stored as shown in FIG. 8B. On the other hand, when the temperature falls below a certain high temperature,
As shown in FIG. 7B, a shape for closing the opening 253 is stored. The lubricating oil recirculation device of the engine equipped with such a relief valve 28a selectively switches between the low-temperature position P1 and the high-temperature position P2 in a steady state similarly to the device of FIG.

On the other hand, the temperature-sensitive drive unit 26 breaks down, the cylindrical valve 25 is fixed at the low-temperature position P1, the lubricating oil becomes hot,
It is assumed that a predetermined high temperature (for example, 115 ° C.) is reached. In this case, each relief valve 28a is displaced from the closed state shown in FIG. 7 (b) to the open state shown in FIG. 8 (b), opening the opening 253 and distributing the lubricating oil on the oil cooler 17 side to the main passage side opening 2.
2, through the main passage hole 245, the opening 253, the bottom frame 252, the boss-shaped frame portion 243, the valve chamber 161 and the downstream outlet 31 to the oil filter 18 and the oil gallery 11 side. Thus, even if the temperature-sensitive drive unit 26 fails, the relief valve 28a can open the opening 253 to release heat of the lubricating oil. Lubrication can be performed properly, failure of the engine body can be avoided, and deterioration of durability can be prevented.

Although each of the relief valves 28 and 28a is formed of a shape memory material, each of the relief valves 28 and 28a may be formed of a bimetal. In this case, the same operation and effect as those of the relief valves 28 and 28a made of the shape memory material described above can be obtained.

[0032]

According to the first aspect of the present invention, when the lubricating oil has a high temperature equal to or higher than a predetermined value, the relief valve opens the main passage and guides the lubricating oil to the oil cooler to lower the oil temperature. It will be. For this reason, even if the switching drive source of the temperature-sensitive control valve fails and prevents the partition wall from guiding the lubricating oil to the oil cooler, if the lubricating oil is at a high temperature equal to or higher than a predetermined value, the relief valve is mainly operated. Since the passage is opened to guide the lubricating oil to the oil cooler to lower the oil temperature, it is possible to reliably prevent the engine body from being damaged due to seizure inside the engine. Moreover, even if the switching drive source is not faulty, if the lubricating oil reaches a high temperature equal to or higher than a predetermined value, the relief valve will open the main passage more greatly, reducing the flow resistance of the main passage and reducing the lubricating oil. To the oil cooler to lower the oil temperature.

According to the second aspect of the present invention, in the engine lubricating oil recirculation device according to the first aspect, a portion corresponding to the main passage is opened at a high temperature equal to or higher than a predetermined value with respect to the relief valve made of a shape memory material. Then, the shape of closing the opening at a low temperature is stored, and the relief valve mounted on the partition wall reliably opens and closes the main passage according to the temperature of the lubricating oil. Therefore, the shape of the relief valve is simplified, the mounting of the relief valve is facilitated, and the cost can be reduced.

According to the third aspect of the present invention, in the engine lubricating oil recirculation system according to the first aspect, the relief valve made of bimetal is displaced so as to open a portion corresponding to the main passage at a high temperature equal to or higher than a predetermined value. Since the opening is displaced so as to close the opening when the temperature is low, the relief valve mounted on the partition wall reliably opens and closes the main passage according to the temperature of the lubricating oil. Therefore, the shape of the relief valve is simplified, the mounting of the relief valve is facilitated, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a lubricating oil recirculation device for an engine of the present invention in a low temperature state.

FIG. 2 is a cross-sectional view of the lubricating oil recirculation device of the engine of FIG. 1 in a high temperature state.

FIG. 3 shows a state of the relief valve of the lubricating oil recirculation device of the engine in FIG. 1 in a low temperature state, where (a) is a partial side sectional view,
(B) is an AA enlarged sectional view of FIG.

FIG. 4 shows a state of the relief valve of the lubricating oil recirculation device of the engine in FIG. 1 in a high temperature state, where (a) is a partial side sectional view,
FIG. 3B is an enlarged sectional view taken along line BB of FIG. 2.

FIG. 5 is a schematic diagram of a lubricating oil circulation system of an engine equipped with the lubricating oil recirculation device of the engine of FIG. 1;

FIG. 6 is a cross-sectional view of a lubricating oil recirculation device for an engine according to another embodiment of the present invention in a low temperature state.

7 shows an embodiment of the relief valve of the lubricating oil recirculation device of the engine in FIG. 6 in a low temperature state, where (a) is a partial side sectional view,
FIG. 7B is an enlarged cross-sectional view taken along the line CC of FIG. 6.

8 shows a state of the relief valve of the lubricating oil recirculation device of the engine in FIG. 6 in a high temperature state, where (a) is a partial side sectional view,
(B) is a plan sectional view of a main part.

FIG. 9 is a cross-sectional view of a conventional lubricating oil recirculation device in a low temperature state.

[Explanation of symbols]

 REFERENCE SIGNS LIST 10 oil pump 12 main passage 13 branch portion 14 engine 141 housing 16 junction 17 oil cooler 18 oil gallery 19 bypass passage 20 temperature-sensitive control valve 20 a temperature-sensitive drive unit 22 main passage side opening 23 bypass side opening 24 casing 244 bypass hole 245 Main passage hole 25 Cylindrical valve 251 Partition wall 253 Opening 26 Temperature-sensitive drive unit 28 Relief valve 28a Relief valve

Claims (3)

(57) [Claims] 1. A bypass passage for flowing lubricating oil bypassing an oil cooler provided in the main passage, is provided in the middle of a main passage connecting the oil pump and an oil supply portion in the engine.
A temperature-sensitive control valve is provided at one of a branch portion and a junction portion of the two passages, and the temperature-sensitive control valve switches and drives a partition wall in accordance with a temperature of the lubricating oil. In a lubricating oil recirculation device for an engine in which a partition wall selectively flows lubricating oil to the bypass passage or the main passage, the lubricating oil mounted on the partition wall has a high temperature of a predetermined value or more. A lubricating oil recirculation device for an engine, comprising: a relief valve for automatically opening a portion corresponding to the main passage when sensing. 2. The lubricating oil recirculation system for an engine according to claim 1, wherein said relief valve is formed of a shape memory material. 3. The lubricating oil recirculation system for an engine according to claim 1, wherein the relief valve is formed of a bimetal.