JPH10131725A - Valve characteristic control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve characteristic control device for internal combustion engine, which can improve the discharging property of the operating oil discharged from a hydraulic actuator through a drain passage and which can restrict the lowering of seal performance of a control valve. SOLUTION: A control valve (OCV) 44 for controlling a VVT actuator is provided inside of a housing 50, which is formed of a cylinder head, and provided with a sleeve 51, a spool and a solenoid 53. A part of a second drain passage 82, which is opened in a second drain port 58, is positioned outside of an end surface wall of a housing recessed part of the housing 50. The second drain passage 82 can be opened at the maximum in relation to the second drain port 58 formed into long hole shape. Namely, with a view limited to the second drain passage 82, since opening shape thereof is not formed into the shape of a drill hole, but it can be formed into a desirable shape, opening area of an overlapped part of the opening part of the second drain passage 82 and the second drain port 58 can be secured at the maximum.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve characteristic control device for an internal combustion engine that controls the opening and closing characteristics of a valve of the internal combustion engine by using the hydraulic pressure of hydraulic oil.

[0002]

2. Description of the Related Art Conventionally, as this kind of technique, for example, one disclosed in Japanese Patent Application Laid-Open No. 8-4511 is known. In general, a ring-shaped piston (ring gear) having a helical spline on its outer periphery is provided on the outer periphery of a camshaft in an internal combustion engine provided with a variable valve timing mechanism (VVT). This ring gear is urged in one axial direction by a spring. Further, the hydraulic pressure of the hydraulic oil from the oil pump is adjusted by, for example, a hydraulic control valve of a linear solenoid type and supplied to a hydraulic chamber of the VVT.

That is, as shown in FIGS. 6 and 7, a hydraulic control valve 101 is provided with a sleeve 10 housed inside a housing 102 constituted by an engine cylinder head.
3 and a spool 104 slidably provided inside the sleeve 103. Also, the hydraulic control valve 101
(Sleeve 103) has a supply port 105 to which hydraulic oil from an oil pump is supplied, a discharge port 106 to discharge to the hydraulic chamber, and a drain port for returning hydraulic oil from the hydraulic chamber to the oil pan. 107 are provided. When the engine is operating, the linear solenoid 108 is controlled, and the hydraulic pressure adjusted by the hydraulic control valve 101 is introduced into the hydraulic chamber. With this introduction, the ring gear receives hydraulic pressure in the axial direction of the camshaft,
Move accordingly. At this time, due to the presence of the helical spline, the rotation phase of the camshaft and the pulley that is drivingly connected to the engine changes, and as a result, the opening and closing timing of the valve is adjusted.

By the way, as described above, the sleeve 10
3 includes one supply port 105 and two discharge ports 106.
And two drain ports 107 are formed. As shown in FIG. 7, these ports (openings) 105 to 107 are formed in a long hole shape so as to be orthogonal to the axial direction so as to ensure the maximum allowable communication area.

[0005]

However, the above prior art has the following problems. That is,
Since the above-mentioned sleeve 103 can be cut, the openings (openings) 105 to 107 could be formed in a long hole shape. On the other hand, the communication path 111 that connects the oil pump to the supply port 105, the communication path 112 that connects the discharge port 106 and the hydraulic chamber, and the communication path 113 that connects the oil pan and the drain port 107 are each Also, it is necessary to drill holes in the cylinder head (housing 102) of the engine. For this reason, the opening shapes of these communication passages 111 to 113 are two in FIG.
As shown by the dotted line (inside), the shape was limited to a circular shape. Therefore, the common portion area (effective area) of the two openings is equal to the length of each of the openings 105 to 10 formed in the shape of a long hole.
It was considerably reduced compared to 7. As a result, there is a possibility that a problem may occur, for example, such that the dischargeability of the hydraulic oil discharged through the communication passage 113 is impaired.

On the other hand, in order to increase the effective area even slightly, it is conceivable to increase the hole diameter of the communication passages 111 to 113 as shown by a two-dot chain line (outside) in FIG. The sealing area between the sleeve 103 and the cylinder head serving as the housing 102, and consequently the sealing force, is reduced by an amount corresponding to the increase. For this reason, there is a fear that it is necessary to be concerned about leakage of hydraulic oil.

The present invention has been made in view of the above circumstances, and has as its object to provide a control valve for controlling the operation of a hydraulic actuator provided to change the valve opening / closing characteristics of an internal combustion engine. In the valve characteristic control device for an internal combustion engine, it is possible to improve the dischargeability of hydraulic oil discharged from a hydraulic actuator via a drain passage, and to suppress a decrease in the sealing property of a control valve. An object of the present invention is to provide an engine valve characteristic control device.

[0008]

According to the present invention, there is provided a hydraulic actuator provided to change a valve opening / closing characteristic of an internal combustion engine, and a hydraulic actuator supplied with hydraulic oil from a hydraulic source. A supply passage, a control valve for opening and closing a supply passage for supplying the hydraulic oil to the hydraulic actuator and a drain passage for the hydraulic oil discharged from the hydraulic actuator, and a tubular sleeve having a plurality of through holes; And a control valve having a spool that moves in the axial direction by being driven by a driving device inside the sleeve and opens and closes the plurality of through holes, and a control unit that controls the driving device, and A control valve is fitted into a recess formed in the internal combustion engine body, at least one of the plurality of through holes is communicated with the supply passage, and at least one of the through holes is One of which communicates with the supply passage, and at least one of the through holes communicates with the drain passage. The gist of the invention is that it is opened at a position outside the end wall.

According to a second aspect of the present invention, in the valve characteristic control device for an internal combustion engine according to the first aspect, the hydraulic actuator sets a rotation phase of a camshaft with respect to a rotation of a crankshaft of the internal combustion engine. The gist of the invention is that the valve timing mechanism adjusts the opening / closing timing of a valve driven by the camshaft by changing the hydraulic pressure of hydraulic oil.

According to a third aspect of the present invention, in the valve characteristic control apparatus for an internal combustion engine according to the first or second aspect, the hydraulic oil is prevented from being scattered at a position outside an end wall of the recess. The main point is that a casing is provided for this purpose.

(Operation) According to the first aspect of the present invention, the control valve is fitted in the recess formed in the internal combustion engine main body, and the hydraulic oil from the hydraulic pressure source passes through the supply passage. It is introduced toward the spool valve from the through hole of the cylindrical sleeve of the control valve. The hydraulic oil is introduced from another through hole of the sleeve through the supply passage toward the hydraulic actuator. Thus, the hydraulic actuator operates to change the valve opening / closing characteristics of the internal combustion engine. Moreover,
Hydraulic oil from the hydraulic actuator is discharged through a drain passage through another through hole in the sleeve of the control valve.

The opening and closing of these through-holes is performed by controlling a drive unit by a control means and moving the spool by operating the drive unit. Here, the through hole can be formed in an arbitrary shape by cutting the sleeve or the like. On the other hand, the supply passage, the supply passage, and the drain passage are formed by drilling a hole in the internal combustion engine main body with a drill, and the opening shape in almost all portions thereof is circular.

According to the present invention, the through hole communicating with the drain passage is opened at a position outside the end wall of the recess of the internal combustion engine body. For this reason, if it is limited to the drain passage, the opening shape can be any shape, not a circular shape. Therefore, the opening area (effective area) of the overlapping portion of the opening and the through hole can be maximized. At the same time, the opening does not need to be elongated in the axial direction of the control valve, so that the seal area between the control valve and the internal combustion engine body does not decrease.

According to the second aspect of the invention, in addition to the operation of the first aspect, the hydraulic actuator is constituted by a valve timing mechanism. That is, the rotation phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine changes by using the hydraulic pressure of the hydraulic oil, and the opening / closing timing of the valve driven by the camshaft is adjusted. Thereby, the valve characteristics of the internal combustion engine can be controlled.

Further, according to the third aspect of the present invention,
In addition to the effects of the first and second aspects of the present invention, a casing is disposed outside the end wall of the recess. For this reason, it is possible to prevent the operating oil discharged from the through hole from scattering.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a valve characteristic control device for an internal combustion engine according to the present invention will be described below in detail with reference to the drawings.

FIG. 3 is a diagram schematically showing a hydraulic oil circuit of an engine as an internal combustion engine including a variable valve timing mechanism and a hydraulic control valve constituting the valve characteristic control device according to the present embodiment. The hydraulic oil circuit is oil pan 4
2. Oil pump 41, oil filter 43, valve operating mechanism, crank mechanism, linear solenoid type hydraulic control valve (hereinafter simply referred to as OCV) 44, variable valve timing actuator (hydraulic actuator) constituting variable valve timing mechanism (hydraulic actuator) VVT actuator) 4
8 and various oil paths connecting them.

Hereinafter, each element will be described in detail. The camshaft 1 is provided for driving an intake valve or an exhaust valve of an engine (not shown).
The journal 2 is rotatably supported between a bearing 4 and a bearing cap 5 of a cylinder head 3 as an internal combustion engine body. The journal 2 is formed with two journal grooves 6 and 7 extending along the outer periphery. The cylinder head 3 has journal grooves 6,
A first head oil passage 8 and a second head oil passage 9 are formed as supply passages for guiding hydraulic oil to the journal 7 and the journal 2.

One end of each of the head oil passages 8 and 9 is connected to an OCV 44. The OCV 44 is connected to an oil pan 42 via an oil filter 43, an oil pump 41 as a hydraulic pressure source, and an oil strainer 45. . The oil pump 41 is connected to the engine, and pumps up and discharges hydraulic oil in an oil pan 41 via an oil strainer 45 in conjunction with operation of the engine. After passing through the oil filter 43, the hydraulic oil is introduced into the OCV 44 through a main oil passage 46 as a supply passage, and
By the operation of the OCV 44, the oil is supplied to each of the head oil passages 8 and 9 with a predetermined pressure, and is supplied to each of the journal grooves 6 and 7 and the journal 2. here,
The supply of hydraulic oil to the head oil passages 8 and 9 is performed by the OCV
44 allows it to be adjusted arbitrarily. The detailed configuration of the OCV 44 will be described later.

The oil filter 43 and the OCV 4
4, a part of the main oil passage 46 is formed so as to be branched, and the branched part of the oil passage 46 is used to lubricate the engine main body constituted by a valve mechanism, a crank mechanism, and the like. He is in communication with the system.

Next, the VVT actuator 48 will be described. A timing pulley housing 10 is provided at a distal end (left end in FIG. 3) of the camshaft 1. The housing 10 includes a pulley body 11 and a cover 12 assembled so as to cover one side surface of the pulley body 11 and the tip of the camshaft 1. The pulley body 11 has a substantially disk shape, a plurality of external teeth 13 are formed on the outer periphery, and a boss 14 is formed in the center. The pulley body 11 is mounted by its boss 14 so as to be rotatable relative to the camshaft 1. Further, a timing belt 15 is attached to the external teeth 13, and the timing pulley housing 10 is connected to a crankshaft (not shown) of the engine via the timing belt 15. On the other hand, the cover 12 has a bottomed cylindrical shape, a flange 16 is formed on the outer periphery thereof, and a communication hole 17 is formed in the center of the bottom. A plurality of internal teeth 12 a are formed on the inner periphery of the cover 12. The cover 12 is fixed to one side surface of the pulley main body 11 by a plurality of bolts 18 and pins 19 at its flange 16. In addition, communication hole 1
A cover 20 is detachably attached to 7. The space surrounded by the pulley body 11 and the cover 12 is a housing space 21 formed inside the timing pulley housing 10.

In the housing space 21, an inner cap 22 having a bottomed cylindrical shape is fastened by a hollow bolt 23 to the tip of the camshaft 1 and is prevented from rotating by a pin 24. The peripheral wall 22a of the inner cap 22 is mounted so as to enclose the boss 14 of the pulley body 11, and the two 11 and 22 are relatively rotatable. A plurality of external teeth 22b are formed on the outer periphery of the peripheral wall 22a of the inner cap 22.

A ring gear 25 is interposed between the timing pulley housing 10 and the camshaft 1, and the ring gear 25 connects the two 10, 10 to each other. That is, the ring gear 25 has an annular shape, and the camshaft 1 is accommodated in the accommodation space 21 of the timing pulley housing 10.
Are accommodated so as to be able to reciprocate along the axial direction. A plurality of teeth 25a and 25b are provided on the inner and outer circumferences of the ring gear 25. Then, the inner teeth 25 of the ring gear 25
a is the outer gear 22b of the inner cap 22 and the ring gear 2
The teeth 25b on the outer periphery of the gear 5 mesh with the internal teeth 12a of the cover 12, respectively. Therefore, when the timing pulley housing 10 is rotated, the timing pulley housing 10 and the inner cap 22 connected by the ring gear 25 are integrally rotated, and the camshaft 1 is further integrally rotated with the timing pulley housing 10. You. Further, these two teeth 25a and 25b are helical teeth. Therefore, the camshaft 1 is moved by the axial movement of the ring gear 25 so that the timing pulley housing 1
It rotates relatively to zero.

A first hydraulic chamber 26 is provided between the axial end of the ring gear 25 and the bottom wall of the cover 12 in the housing space 21. Similarly, in the accommodation space 21, the space between the other end of the ring gear 25 in the axial direction and the pulley body 11 is
The second hydraulic chamber 27 is provided.

Here, a first shaft oil passage 28 is formed in the camshaft 1 so as to extend along the center of the camshaft 1 in order to supply hydraulic pressure by hydraulic oil to the first hydraulic chamber 26. The distal end side of the shaft oil passage 28 communicates with the first hydraulic chamber 26 through the center hole 23 a of the hollow bolt 23. The proximal end of the shaft oil passage 28 communicates with the journal groove 6 through an oil hole 29 extending in the radial direction of the camshaft 1.

On the other hand, in order to supply hydraulic pressure by hydraulic oil to the second hydraulic chamber 27, the second shaft oil passage 3 extends in the camshaft 1 so as to extend in parallel with the first shaft oil passage 28.
0 is formed. One peripheral groove 31 is formed at a position near the tip of the camshaft 1 along the outer peripheral surface thereof. A part of the circumferential groove 31 communicates with the second shaft oil passage 30. Further, the boss 1 of the pulley body 11
An oil hole 32 is formed in a part of the hole 4 to allow the above-mentioned peripheral groove 31 to communicate with the second hydraulic chamber 27. The proximal end side of the second shaft oil passage 30 communicates with the journal groove 7. In addition, a spring 33 is provided between the ring gear 25 and the pulley body 11 in the second hydraulic chamber 27 to urge the ring gear 25 to return to the initial position (retard side position) shown in FIG. Have been.

Then, as shown in FIG. 4, the operating oil is supplied to the first head oil passage 8 by the OCV 44,
When the second head oil passage 9 is opened to the oil pan 42, the hydraulic pressure of the working oil is reduced to the journal groove 6 and the oil hole 2.
9, is supplied to the first hydraulic chamber 26 through the first shaft oil passage 28 and the center hole 23a of the hollow bolt 23. When this hydraulic pressure is applied to one end of the ring gear 25,
The ring gear 25 rotates while being moved in the axial direction against the urging force of the spring 33 and the hydraulic pressure in the second hydraulic chamber 27, so that the camshaft 1 is twisted. As a result, the camshaft 1 and the timing pulley housing 10
Is changed in the rotation direction, and the operation timing of the intake valve or the exhaust valve is changed (for example, advanced).

On the other hand, as shown in FIG. 5, the operating oil is supplied to the second head oil passage 9 by the OCV 44 and the first head oil passage 8 is opened to the oil pan 42 to operate the second head oil passage 8. The oil pressure of the oil is supplied to the second hydraulic chamber 27 through the journal groove 7, the second shaft oil passage 30, the circumferential groove 31 and the oil hole 32. When this oil pressure is applied to the other end of the ring gear 25, the ring gear 25 is rotated while being moved in the axial direction against the oil pressure in the first hydraulic chamber 26, and the camshaft 1 is turned in the opposite direction to the above. Torsion is imparted. As a result, the relative position of the camshaft 1 and the timing pulley housing 10 in the rotation direction is changed, and the operation timing of the intake valve or the exhaust valve is retarded, for example.

In this embodiment, when the supply of hydraulic oil to both head oil passages 8 and 9 is stopped by the OCV 44, the ring gear 25 is returned to the stroke end on the maximum retard side by the urging force of the spring 33. Then, it returns to the position described in FIG. In this embodiment, the OCV 44 controls the two hydraulic chambers 26 and 27.
By adjusting the balance of the hydraulic pressure supplied to the ring gear 25, the ring gear 25 can be moved in the axial direction and held at an arbitrary position.

Next, the OCV 44 will be described. As described above, the OCV 44 selectively opens and closes the first head oil passage 8 and the second head oil passage 9 and
Is used to switch the stop position. As shown in FIGS. 1 to 3, the OCV 44 is provided in a housing 50 constituted by the cylinder head 3, and includes a sleeve 51, a spool 52, and a solenoid 5 as a driving device.
3 is provided. More specifically, the sleeve 51 is housed in a housing space 50 a as a recess of the housing 50, and includes a plurality of supply ports 54, a first discharge port 55, a second discharge port 56, and a first drain, which are through holes. It has a port 57 and a second drain port 58. The supply port 54 is connected to the oil pump 41 and forms a supply port in the present embodiment. In addition, the first discharge port 55 is connected to the first head oil passage 8,
The second discharge port 56 is connected to the second head oil passage 9. These two discharge ports 55 and 56 constitute a discharge port in the present embodiment. Further, the first drain port 57 and the second drain port 58 are connected to the oil pan 42 through drain passages 81 and 82, respectively.

The spool 52 is slidably disposed in the sleeve 51 in the front-rear direction (the left-right direction in FIG. 3). On the outer periphery of the spool 52, three annular concave portions 6 are provided.
1, 60, 59 are formed in a state separated from each other in the front-rear direction.

A solenoid 53 is provided in the rear half (the right side in the figure) of the OCV 44, and the spool 52 moves depending on whether or not the solenoid 53 is excited. The duty of this solenoid 53 is controlled by an electronic control unit (hereinafter simply referred to as “ECU”) 71 as control means. That is, the solenoid 53
May or may not be excited depending on the presence or absence of a current supplied to itself. Then, the spool 52 reciprocates in the sleeve 51 according to the excitation state. More specifically, when the solenoid 53 is not excited (for example, duty ratio = 0%), the spool 52 is held at the position shown in FIG. 5 by the urging force of the spring 62 housed at the front end of the sleeve 51. On the other hand, the solenoid 53
Is excited (for example, duty ratio = 100%),
It advances to the position shown in FIG. 4 against the urging force of the spring 62. The spool 52 is provided with a solenoid 53
By repeating the excitation and the non-excitation in a short cycle (for example, duty ratio = 50%), it is held at an appropriate intermediate position, that is, the position shown in FIG.

More specifically, the solenoid 5
3 (duty ratio = 0%), the spool 5
When 2 moves back to the position shown in FIG. 5, the main oil passage 46, the supply port 54, the central annular recess 60, and the second discharge port 56 communicate with each other. Further, the first discharge port 55, the front annular concave portion 61, and the first drain port 57 communicate with each other.
Then, the operating oil from the oil pump 41 is supplied from the second discharge port 56 to the second head oil passage 9. On the other hand, hydraulic oil from the first head oil passage 8 is discharged from the first discharge port 55 to the oil pan 42 via the first drain port 57 and the first drain passage 81.

When the spool 52 advances to the position shown in FIG. 4 by the excitation of the solenoid 53 (duty ratio = 100%), the main oil passage 46, the supply port 5
4. The central annular recess 60 and the first discharge port 55 communicate with each other. The second discharge port 56, the rear annular concave portion 59, and the second drain port 58 communicate with each other. Then
The operating oil from the oil pump 41 is supplied to the first discharge port 5
5 to the first head oil passage 8. On the other hand, the second
The hydraulic oil from the head oil passage 9 of the second discharge port 56
From the oil pan 42 through a second drain port 58 and a second drain passage 82.

Further, when the spool 52 is held at the position shown in FIG. 3 by repeating the excitation and non-excitation of the solenoid 53 (duty ratio = 50%), the central annular recess 6
0 will be closed at the exit side. That is, the hydraulic oil introduced from the supply port 54 is supplied to the central annular recess 6.
0, the first and second discharge ports 55, 56
Is not ejected to any of them. Then, the hydraulic oil passes through the main oil passage 46 and is supplied only to the engine body lubrication system such as the valve operating mechanism and the crank mechanism.

That is, the spool 52 moves in the front-rear direction according to the duty ratio at that time, and switches the flow of hydraulic oil. When the duty ratio is around 50% (40% to 60%), the spool 52 is held at the intermediate position, and the supply amount of the working oil to the VVT actuator 48 becomes substantially “0”.

The solenoid 53 of the OCV 44 has an EC
The drive is controlled by U71. Specifically, the ECU 71
Various sensors are connected to the input side of. Also, E
The output side of the CU 71 has a solenoid 53 of the OCV 44.
Is connected. The ECU 71 determines the state of the engine at that time based on the detection signals from the various sensors and outputs a control signal for driving the solenoid 53.

Next, a characteristic portion of the present embodiment will be described. As shown in FIGS.
The supply port 54, the first discharge port 55, the second discharge port 56, the first drain port 57, and the second drain port 58 formed on the fourth sleeve 51 are orthogonal to the axial direction by cutting. And is formed in a long hole shape. In addition, various passages except for a part of the second drain passage 82 (the first head oil passage 8, the second head oil passage 9, the main oil passage 46, the first drain passage 81, and the second drain passage 81). 82 on the oil pan 42 side is formed by forming a hole by drilling. Accordingly, these various passages except for a part of the second drain passage 82 have circular openings. On the other hand, the portion of the second drain passage 82 that opens to the second drain port 58 is located outside the end wall of the housing recess 50a of the cylinder head 3 (housing 50). In other words, the second drain port 58 is opened to a part of the second drain passage 82 located outside the end face wall newly formed into a concave shape by the cutting process in the housing concave portion 50a. Have been.

In this embodiment, a plate 83 as a casing for preventing scattering of hydraulic oil is further provided outside.
Are arranged. Next, the operation and effect of the present embodiment configured as described above will be described. The ECU 71
The operation when the valve timing is controlled to the advance side or the retard side by the control of the OCV 44 is already described in the above-described components, and the description is omitted here, and the operation of the characteristic portion is omitted. And effects will be described.

(A) In the above embodiment, the portion of the second drain passage 82 that is open to the second drain port 58 is provided outside the end wall of the housing recess 50a of the cylinder head 3 (housing 50). To be positioned closer to Therefore, the second drain passage 82 can be opened to the maximum with respect to the second drain port 58 formed in a long hole shape. That is, if it is limited to the second drain passage 82, the opening shape is not circular,
Since an arbitrary shape can be obtained, an opening area (effective area) of an overlapping portion of the opening and the second drain port 58 can be ensured to the maximum. As a result, it is possible to improve the dischargeability of the hydraulic oil discharged through the second drain passage 82.

(B) At the same time, the opening does not need to be elongated in the axial direction of the OCV 44. Therefore, a reduction in the sealing area between the OCV 44 and the housing 50 and a reduction in the sealing force do not occur. As a result, there is no need to worry about problems such as leakage of hydraulic oil.

(C) Further, a plate 83 as a casing is arranged outside the end face wall of the housing 50. For this reason, the second drain port 58
It is possible to prevent the operating oil discharged from the nozzle from scattering.

Note that the present invention is not limited to the above-described embodiment, and may be implemented as follows by appropriately changing a part of the configuration without departing from the spirit of the invention. (1) In the above embodiment, the timing belt 15 is attached to the external teeth 13.
A configuration in which a timing chain is attached instead of 5 may be adopted. In such a case, a casing that replaces the plate 83 can be configured by the timing chain case.

(2) In the above embodiment, the ring gear 2
Although the configuration in which the spring 33 is interposed between the pulley 5 and the pulley body 11 is employed, the spring 33 may be omitted.

(3) In the above embodiment, the ring gear 2
Although both the inner and outer teeth 25a and 25b of 5 are helical teeth, only one of the inner and outer teeth 25a and 25b may be helical teeth.

(4) Instead of the VVT actuator 48 in the above embodiment, a vane type VVT actuator may be used. (5) In the above embodiment, the oil pump 41 and the O
A modulating valve as a constant pressure valve may be provided between the CV 44 and the CV 44. With this configuration, the hydraulic pressure supplied to the VVT actuator 48 becomes substantially a predetermined value, so that the variable response, controllability, and durability can be improved.

[0047]

As described in detail above, according to the present invention,
In a valve characteristic control device for an internal combustion engine provided with a control valve for controlling operation of a hydraulic actuator provided to change a valve opening / closing characteristic of the internal combustion engine, hydraulic oil discharged from the hydraulic actuator through a drain passage It is possible to improve the dischargeability of the control valve and to suppress a decrease in the sealing property of the control valve.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional view showing a variable valve timing hydraulic control valve according to an embodiment.

FIG. 2 is a sectional view taken along line BB of FIG. 1 according to one embodiment;

FIG. 3 is a cross-sectional view schematically showing a valve timing control device including a VVT actuator and a hydraulic control valve in one embodiment.

FIG. 4 is a cross-sectional view illustrating a state of the valve timing mechanism when the spool moves in one embodiment.

FIG. 5 is a cross-sectional view illustrating a state of the valve timing mechanism when the spool moves in one embodiment.

FIG. 6 is a partial cross-sectional view showing a variable valve timing hydraulic control valve according to the related art.

FIG. 7 is a sectional view taken along line AA of FIG. 6;

FIG. 8 is a schematic projection view of an opening.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Cam shaft, 3 ... Cylinder head as an internal combustion engine main body, 8 ... First head oil passage as a supply passage, 9 ...
A second head oil passage as a supply passage, 41 an oil pump as a hydraulic pressure source, 44 an OCV as a control valve, 46
.., A main oil passage as a supply passage; 48, a VVT actuator constituting a valve timing mechanism (hydraulic actuator); 50, a housing; 51, a sleeve;
2 ... Spool, 53 ... Solenoid as drive device, 5
4 ... supply port forming a through hole, 55 ... first discharge port forming a through hole, 56 ... second discharge port forming a through hole, 57 ... first drain port forming a through hole, 58 ... Second drain port forming through hole, 81
... a first drain passage, 82 ... a second drain passage.

Claims (3)

[Claims] 1. A hydraulic actuator provided to change a valve opening / closing characteristic of an internal combustion engine, a supply path to which hydraulic oil from a hydraulic source is supplied, and a supply path to supply the hydraulic oil to the hydraulic actuator And a control valve for opening and closing a drain passage for hydraulic oil discharged from the hydraulic actuator, wherein the cylindrical sleeve has a plurality of through-holes, and the inside of the sleeve is driven by a driving device to drive in the axial direction. And a control valve having a spool that opens and closes the plurality of through-holes, and control means for controlling the driving device, wherein the control valve is fitted into a recess formed in the internal combustion engine body. At least one of the plurality of through-holes communicates with the supply passage, at least one of the through-holes communicates with the supply passage, A valve characteristic control device for an internal combustion engine having at least one communicating with the drain passage, wherein a through hole communicating with the drain passage is opened at a position outside an end face wall of the concave portion. Valve characteristic control device for internal combustion engine. 2. The valve according to claim 1, wherein the hydraulic actuator changes a rotation phase of a camshaft with respect to a rotation of a crankshaft of the internal combustion engine using hydraulic pressure of hydraulic oil to open and close a valve driven by the camshaft. The valve characteristic control device for an internal combustion engine according to claim 1, wherein the valve characteristic control device is a valve timing mechanism for adjusting timing. 3. The valve characteristic control of an internal combustion engine according to claim 1, wherein a casing for preventing scattering of the hydraulic oil is provided at a position outside the end face wall of the concave portion. apparatus.