JPH119910A - Lubricating hydraulic circuit of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce manufacturing cost without necessitating both machining of the body part of an engine and additional parts to instal a control valve in relation to an hydraulic controlling device in the lubricating oil system of an internal combustion engine. SOLUTION: The casing 100 of an oil filter is fitted to the fitting part 102 of an engine block. An annular filter element 106 is fitted to the casing 100 by a cap 110. A control valve 122 is provided coaxially for the filter element 106. The control valve 122 controls distribution of lubricating oil flow rate for both a necessary part side of lubrication and a valve timing variable mechanism. The control valve 122 is formed into an orifice, by which flow rate on the necessary part side of lubrication is throttled to the necessary lowest limit at time of low oil pressure, and controls oiling for the valve timing variable mechanism so that oiling is preferentially performed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lubricating hydraulic circuit for an internal combustion engine provided with a hydraulic actuator provided for controlling the operation of the internal combustion engine such as variable valve timing and operating in accordance with the operation state of the internal combustion engine. .

[0002]

2. Description of the Related Art An internal combustion engine operation control device such as a variable valve timing mechanism (VVT) uses a lubricating oil pressure of the internal combustion engine as a power source. The oil pressure to the variable valve timing mechanism is supplied from the lubricating oil pump of the internal combustion engine to an oil filter (for the structure of the oil filter, see Japanese Utility Model Application Laid-Open No. 6-85007, etc.) to the parts requiring lubrication to the bearings and valve train. From the lubricating oil passage. The hydraulic pressure is selectively sent to the variable valve timing mechanism according to the operating conditions of the internal combustion engine, and the desired valve timing control is performed.

[0003] When the temperature of the lubricating oil is high, its viscosity decreases, and the oil pressure from the lubricating oil pump drops for the same engine speed. On the other hand, when the engine speed decreases, the hydraulic pressure decreases. Therefore, in a state where the temperature of the lubricating oil is high and the engine speed is low, the decrease in the oil pressure of the lubricating oil is large due to the sum of the effects of these two. Even if the oil pressure decreases, oil supply with low pressure loss is performed in the bearing portion and the valve train, and the oil amount necessary for lubrication can be secured. However, since the required high oil pressure is not supplied to the VVT, the operation of the hydraulic mechanism is slow during the valve timing control, and the response of the valve timing control is deteriorated. Further, the stability of the valve timing control deteriorates.

Therefore, a control valve for controlling the distribution of the oil amount to the lubricating portion and the oil amount to the VVT is arranged at a branch portion of the hydraulic passage to the lubricating portion of the internal combustion engine and to the hydraulic passage to the VVT. One has been proposed by the applicant.

[0005]

The location where the distribution control valve is to be installed will usually be the main body (cylinder block) of the internal combustion engine. In this case, however, machining of the cylinder block is indispensable, Since the number of points also increases, there is a possibility that manufacturing costs will increase. SUMMARY OF THE INVENTION An object of the present invention is to reduce the manufacturing cost without the need for machining the engine body or additional parts for installing the control valve.

[0006]

The present invention employs the technical means described in claim 1 to solve the above-mentioned problems. According to this technical means, processing of the engine block can be minimized and the number of parts can be reduced by incorporating the control valve in the casing of the oil filter.

According to the second aspect of the present invention, since the casing of the oil filter can be mounted at a fixed angular position, the direction of the passage for taking out the control oil pressure to the variable valve timing mechanism is the same as the desired direction. can do. According to the third aspect of the present invention, the filter element and the control valve are coaxial, and a structure for accommodating the control valve in the central opening of the filter element is realized, and the size can be reduced.

According to the fourth aspect of the present invention, the filter element can be easily attached and detached.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The application of the present invention to a variable valve timing mechanism (VVT) will be described with reference to the drawings. In FIG. 1, reference numeral 10 denotes a cylinder head of an internal combustion engine, and a camshaft 12 is rotatable. It is pivoted on. At one end of the camshaft 12, a timing pulley 14 is rotatably mounted on the camshaft 12 at its sleeve portion 14-1. The pulley section 14-2 of the timing pulley 14 is connected to a timing pulley (not shown) on a crankshaft by a timing belt 16, and the rotational motion of the crankshaft is transmitted to the timing pulley 14.

The power transmission cup 18 has a flange portion 18-1.
The hub 14-3 of the timing pulley 14 is
Has been concluded. The timing piston 22 is arranged inside the power transmission cup 18. Timing piston 2
Reference numeral 2 denotes a first side of the timing piston 22 which is slidable in the axial direction with respect to the sleeve portion 14-1 of the timing pulley 14 and faces the hub portion 14-3 of the timing pulley 14.
A hydraulic chamber 26 is formed, and a second hydraulic chamber 28 is formed on the other side of the timing piston 22 facing the power transmission cup 18. The connection plate 30 is provided inside the power transmission cup 18.
The connecting plate 30 is prevented from rotating with respect to the camshaft 12 by a pin 32, and is fastened to the end of the camshaft 12 by a hollow bolt 34. The cover plate 36 is fitted in the opening of the power transmission cup 18.

The timing piston 22 has splines 22A and 22B at least one of which is inclined with respect to the axis of the camshaft 12 on the outer circumference and the inner circumference thereof, and the spline 22A on the outer circumference is formed on the inner circumference of the power transmission cup 18. The inner spline 22B meshes with the spline 30A formed on the outer periphery of the connecting plate 30. The outer periphery of the timing piston 22 is spline-engaged with the power transmission cup 18 on the timing pulley 14 side, and the inner periphery of the timing piston 22 is
Due to the configuration in which the spline engages with the connection plate 30 on the side, the movement of the timing piston 22 in the axial direction is performed because the spline is inclined with respect to the axial direction.
By causing relative rotation between the camshaft 12 and the timing pulley 14, the valve timing can be changed.

A valve timing control valve (OCV) 38 controls the first hydraulic chamber 2 to control the valve timing to a desired value.
6. It is provided to switch the introduction of the hydraulic pressure to the second hydraulic chamber 28. That is, the valve timing control valve 38 is configured as a 5-port 2-position valve, and its valve body 38A is
When in the position, the first switching port 38-1 connected to the first hydraulic chamber 26 is connected to the high-pressure port 38H connected to the hydraulic pressure source side and connected to the second hydraulic chamber 28 as described later. The second switching port 38-2 is connected to a low pressure port 38L1 connected to the oil pan 52 as described later. Therefore, the hydraulic pressure in the high pressure port 38H passes through the pipe 40 from the first switching port 38-1 in the direction of arrow f _1, the passage of the cylinder head 10 4
2. The hydraulic pressure in the second hydraulic chamber 28 is introduced into the first hydraulic chamber 26 through the passage 43 in the camshaft 12, and the hydraulic pressure in the second hydraulic chamber 28 is changed into the passage 44 in the hollow bolt 34, the passage 45 in the camshaft 12, and the cylinder head 10. through the passage 46, flows through pipe 48 as shown by an arrow f _2, it is returned to the low pressure port 38L1 from the second switching port 38-2. That is, the first hydraulic chamber 26 has a high pressure, the second hydraulic chamber 28 has a low pressure, and the timing piston 22 moves to the left (at this time, the valve timing is, for example, a value on the advance side).

When the valve timing control valve 38 is switched to the second position, the valve body 38A extends to the left,
A second switching port 38-2 connected to the hydraulic chamber 28 is connected to a high pressure port 38H, and a first switching port 38-1 connected to the first hydraulic chamber 26 is connected to a low pressure port connected to an oil tank as described later. Connected to port 38L2. Therefore, high pressure port 38
The hydraulic pressure of H flows from the second switching port 38-2 through the pipe 48 to the arrow f _3.
, And is introduced into the second hydraulic chamber 28 through a passage 46 in the cylinder head 10, a passage 45 in the camshaft 12, and a passage 44 in the hollow bolt 34.
The hydraulic pressure in the pipe 6 passes through the passage 43 in the camshaft 12 and the passage 42 in the cylinder head 10 and flows through the pipe 40 through an arrow f.
Flow as shown in _{4 and} the low pressure port 38 from the first switching port 38-1
Returned to L2. That is, the first hydraulic chamber 26 has a low pressure, the second hydraulic chamber 28 has a high pressure, and the timing piston 22 moves rightward (the valve timing becomes a value on the retard side).

When a predetermined valve timing is obtained, the valve timing control valve is set to the neutral position.
In this neutral position, the first switching port 38-1 and the second switching port 38-2 are completely closed by the valve body 38A, and the high-pressure port
Neither the 38H nor the low pressure ports 38L1 _and 38L2 communicate. Therefore, the timing piston does not move its position and the valve timing is kept at that value.

The operation for the valve timing control will be briefly described. A target valve timing Vi (= position of the timing piston 22 and the like) is calculated by a map based on operating conditions such as a rotation speed and a load, and the valve timing actually detected is calculated. The valve timing control valve 38 is feedback-controlled so that Vx matches the target valve timing Vi.

Next, the supply of operating oil pressure to the timing mechanism (VVT) of the internal combustion engine will be described. The lubricating oil pump 50 is driven by the crankshaft of the internal combustion engine, and the lubricating oil from the oil pan 52 is passed through a strainer 53. Pumped up,
The pressure is fed to the lubricating oil passage 54. A relief valve 56 for metering is provided in the lubricating oil passage 54 near the outlet of the lubricating oil pump 50.
Is provided. 57 is an oil filter. The lubricating oil passage 54 is connected to each part of the internal combustion engine where lubrication is required, that is, an oil supply passage 62 to a connecting rod of each cylinder and an oil supply passage 64 to a valve train. A high-pressure passage 66 for taking out the operating oil pressure to the variable valve timing mechanism is provided.
Is branched from the lubricating oil passage 54 upstream of the passages 62 and 64 to the parts requiring lubrication of the internal combustion engine, and a high pressure port is provided to guide the oil pressure required for the valve timing switching operation as described above to the valve timing control valve 38. Connected to 38H. Also, the low pressure port 38 of the valve timing control valve 38
Low pressure passages 68 from L1 and 38L2 are connected to oil pan 52. Reference numeral 70 denotes a distribution control valve. In the present invention, the distribution control valve 70 and the oil filter 57 constitute a single assembly 71 as described later. The distribution control valve 70 is located in the main lubricating oil passage 54 downstream of the branch point to the lubricating oil passage 54. The valve element 70-1 of the control valve 70 is configured such that the hydraulic pressure is preferentially supplied to the VVT side in the state of the minimum hydraulic pressure where the lubricating oil temperature is high and the internal combustion engine speed is low. That is, in the state of the minimum hydraulic pressure, the amount of lubrication to the lubrication required portion of the internal combustion engine is reduced to the minimum necessary for ensuring the lubrication performance, and the rest is directed to the VVT side. That is, the control valve 70 sets the spring constant of the spring 70-3 so as to form a predetermined gap G between the valve seat 70-2 and the predetermined gap G for securing a required amount of oil to a portion requiring lubrication of the internal combustion engine. Also, the lift amount is increased as the hydraulic pressure is increased. FIG. 2 shows the relationship between the hydraulic pressure applied to the control valve 70 and the passage area ratio (the opening area ratio of the flow control valve 70 to the area of the lubricating oil passage). As shown in the drawing, when the hydraulic pressure applied to the control valve is small, the passage area ratio is maintained at a fixed small value determined by the size of the gap G, and is applied to the control valve after the pressure applied to the control valve has increased to _a predetermined value pa. passage area ratio in proportion to the hydraulic pressure increases after reaching a predetermined pressure p _b is set to be fixed to the maximum passage area ratio. The opening area at low pressure is reduced to the minimum necessary, and the lubricating oil pressure on the upstream side of the flow control valve 70 is increased by giving priority to lubrication to the VVT, thereby improving the response speed in the variable valve timing mechanism. Can be. In the prior art, no distribution control valve was provided. In this case, since the lubricating oil temperature is high and the engine speed is low, there is a problem that the responsiveness at the time of switching the valve timing when the pressure in the lubricating oil supply passage becomes low is deteriorated. During operation in which the lubricating oil temperature is high and the engine speed is low and the lubricating oil pressure is low, the distribution control valve 70 reduces the amount of lubrication to the parts requiring lubrication to the minimum necessary, and supplies the lubricating oil to the variable valve timing mechanism preferentially This makes it possible to ensure the necessary responsiveness when changing the valve timing during operation with a high lubricating oil temperature and a low engine speed.

A specific example of the integrated structure of the distribution control valve 70 and the oil filter 57 in the present invention will be described with reference to FIG. The casing 100 is fixed on a cylinder block 102 of the internal combustion engine via a seal ring 103.
The hollow mounting portion 107 extends along the central axis of the casing 100.
Are formed integrally, and the hollow member 104 is inserted and fixed coaxially to the hollow mounting portion 107. The hollow member 104 has an oil hole 102-1 whose lower end is formed in the cylinder block 102.
The oil hole 102-1 is provided in a hydraulic supply passage (corresponding to the passage 54 in FIG. 1) to the main bearing and the bearing of each cylinder.
Has become part of. Tubular filter element 106
The lower end of the inner peripheral opening (corresponding to the filter 70 of FIG. 1) is inserted into the upper end of the hollow mounting portion 107 via the spacer 108. The filter cap 110 has a spacer 112 and a holding spring 1 at the upper end of the inner peripheral opening of the filter element 106 at the holding projection 108-1 on the inner surface thereof.
14, and the outer periphery of the filter cap 110 is inserted into the casing 100 via a seal ring 116. On the other hand, an annular fixing claw portion 100-1 is formed on the inner peripheral portion of the casing 100, and the filter cap 1 is formed.
An annular groove 110-1 having a sufficient height with respect to the height of the claw portion for receiving the claw portion 100-1 is formed in the inner periphery of the groove 10. Therefore, the filter element 106 is held between the casing 100 and the cap 110 with an appropriate elastic force. An annular oil chamber 120 is formed on the outer periphery of the filter element 106.
0 is an oil hole 102- formed in the cylinder block 102.
The oil hole 102-2 forms a part of a lubricating oil passage 54 for supplying lubricating oil from the lubricating oil pump 50 of FIG. The oil chamber 120 is connected to a high-pressure passage (66 in FIG. 1) to a variable valve timing mechanism (VVT) via a union 121 formed on a peripheral wall of the casing 100. In FIG. 4, the cylindrical mounting portion 107 of the casing has a key portion 107-1 extending in the axial direction along the hollow member 104.
2 is engaged with an axial groove 102-3 formed in the second groove. As a result, the angular position when the casing 100 is attached to the engine block 102 becomes constant, and the high-voltage circuit 6
The direction of the union 121, which is an attachment portion to the sixth unit 6, can be made constant.

The control valve 70 shown in FIG.
4 is configured as a valve body 122 that is housed vertically movable. FIG. 5 shows the valve body 122 in an enlarged manner, and a spring 124 (corresponding to 70-3 in FIG. 1) includes a valve body 122.
Is urged upward so as to be seated on a valve seat portion 104-1 (corresponding to 70-2 in FIG. 1) formed at the upper end of the hollow member 104 (see the broken line). 133 is a spring 124
It is a sheet for. Notches 122-1 are formed at a plurality of positions on the upper end surface of the valve body 122. These notches 122-1 are provided with orifices (see FIG. 1) for securing the minimum flow rate to the lubrication-required portion of the internal combustion engine described in FIG. 1 when the valve body 122 is seated (when the hydraulic pressure is low).
(Equivalent to the gap G). FIG. 6 shows another embodiment of the valve body. In this case, an opening 122-
1 is formed, and this opening serves as an orifice for ensuring the minimum flow rate at low hydraulic pressure.

In FIG. 3, the hollow member 104 and the mounting portion 1
07, an opening 104-2 is formed at the upper end of the hollow member 104 so that the opening thereof is controlled by the valve body 122, and the lower end of the hollow member 104 is provided below the spring seat 133. An opening 104-3 is formed at the position, and these openings 104-2 and 104-3 are
4 for communication with the lubricating oil passage.

The operation of the assembly 71 of the present invention constituted as an oil filter incorporating a lubricating oil distribution control valve will be described. Lubricating oil from the lubricating oil pump is introduced into the oil chamber 120 through the opening 102-2 (arrow). a), oil chamber 120
The light passes through the filter element 106 in the radial direction (arrow b) and is introduced into the hollow member 104 through the opening at the upper end thereof. When the oil pressure is low due to the low lubricating oil temperature and the low rotation speed of the internal combustion engine, the oil pressure
24 is insufficient to displace the valve element 122.
Therefore, the valve body 122 takes a position to be seated on the valve seat 104-1. At this time, the notch 122-1 formed at the upper end of the valve body 122
Flows into the annular chamber 130 through the orifice and the opening 104-2. The lubricating oil flows from the annular chamber 130 into the hollow member 104 through the opening 104-3 (arrows c and d), and enters the lubricating portion such as the main bearing of the internal combustion engine through the opening 102-1 in the cylinder block. The minimum required amount is refueled. The remaining lubricating oil is supplied to an oil supply passage (union 121) to the VVT as shown by an arrow e. VV at low oil pressure
By such preferential refueling to T, it is possible to ensure the responsiveness required for switching the valve timing.

As the hydraulic pressure increases, the valve body 122 is displaced against the spring 124 as shown by the solid line in FIG. 2 and the opening area increases, so that the amount of oil flowing into the opening 104-2 (arrow c, arrow c). d) In other words, the operation described with reference to FIG. 1 in which the amount of old oil to the lubrication-required portion of the internal combustion engine increases in accordance with the pressure is obtained.

[Brief description of the drawings]

FIG. 1 is an overall schematic configuration diagram of a variable valve timing mechanism.

FIG. 2 is a graph showing a relationship between a hydraulic pressure applied to a flow control valve and a passage area ratio.

FIG. 3 is a sectional view showing details of an integrated structure of a filter element and a control valve according to the present invention.

FIG. 4 is a sectional view taken along line IV-IV in FIG. 3;

FIG. 5 is a detailed view of the control valve of FIG. 3;

FIG. 6 is a view showing a control valve according to another embodiment.

[Description of Signs] 10 ... Cylinder head 12 ... Cam shaft 14 ... Timing pulley 16 ... Timing belt 18A, 22A, 22B, 30A ... Spline 22 ... Timing piston 38 ... Valve timing control valve (OCV) 50 ... Lubricating oil pump 52 ... Oil pan 54 Lubricating oil passage 56 Relief valve 66 High pressure passage 70 Flow control valve 100 Casing 102 Engine block 104 Hollow member 106 Filter element 107 Hollow mounting part 110 Filter cap 120 Oil chamber 122 Valve body

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Tokio Obama 14 Iwatani, Shimowasumi-cho, Nishio-shi, Aichi Japan Auto Parts Research Institute, Inc.

Claims (4)

[Claims] In an internal combustion engine provided with a variable valve timing mechanism controlled by oil pressure, a branch between a hydraulic path to a portion requiring lubrication of the internal combustion engine and a hydraulic path to the variable valve timing mechanism is connected to the internal combustion engine. A lubricating hydraulic circuit for an internal combustion engine, comprising: a control valve for controlling distribution of an oil amount and an oil amount to a variable valve timing mechanism, wherein the control valve is incorporated in a casing of an oil filter. 2. The lubricating oil for an internal combustion engine according to claim 1, wherein the casing of the oil filter has a fitting structure that keeps a relative angle position of the casing relative to a mounting portion of the internal combustion engine. circuit. 3. The lubricating oil circuit of an internal combustion engine according to claim 1, wherein the annular filter element of the oil filter is disposed substantially coaxially with the control valve. 4. The lubricating hydraulic circuit for an internal combustion engine according to claim 1, wherein the filter element of the oil filter is detachably attached to the casing by a cap.