JPH084509A - Hydraulic control valve for variable valve timing - Google Patents

Abstract

PURPOSE:To suppress foreign matter from entering the inside of a control valve and valve timing mechanism so as to avoid malfunctioning even if foreign matter such as chips is present. CONSTITUTION:A timing pulley is provided at the top of a camshaft, and a ring gear is provided between the camshaft and the timing pulley. A hydraulic chamber is provided between the camshaft and the timing pulley on both sides of the ring gear in axial direction. Also hydraulic pressure is supplied selectively to each hydraulic chamber by an oil control valve(OCV) 44 so as to move the ring gear in axial direction and rotate the camshaft relatively to the timing pulley. The OCV44 is provided with a housing 50, a sleeve 51, a spoil, and others. A foreign matter storing recessed part 65 open to a supply port 54 is formed around the periphery of the sleeve 51 so that it extends in the flow direction of hydraulic oil. Thus foreign matter mixed with hydraulic oil is stored and held in the foreign matter storing recessed part 65 and thus, even if much hydraulic oil flows into a VVT actuator by the movement of the spool, foreign matter will not flow out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydraulic control valve for a variable valve timing mechanism which makes variable the opening / closing timing of a valve of an internal combustion engine by utilizing the hydraulic pressure of hydraulic oil. For more details,
The present invention relates to a variable valve timing hydraulic control valve for controlling the pressure of hydraulic oil introduced from an oil pump to a variable valve timing mechanism.

[0002]

2. Description of the Related Art Conventionally, as this type of technology, for example, the one disclosed in Japanese Patent Application Laid-Open No. 4-175429 is known. A ring-shaped piston (ring gear) having a helical spline on its outer circumference is provided on the outer circumference of a camshaft in an internal combustion engine equipped with a general variable valve timing mechanism including this technique. The ring gear is biased in one axial direction by a spring. Also, the hydraulic pressure of the hydraulic oil from the oil pump
For example, the pressure is adjusted by a linear solenoid type hydraulic control valve and supplied to the hydraulic chamber.

That is, the hydraulic control valve includes a housing,
The housing includes a sleeve housed inside the housing, and a spool slidably provided inside the sleeve. Further, the hydraulic control valve is provided with a supply port to which hydraulic oil from the oil pump is supplied and a discharge port for discharging the hydraulic oil to the hydraulic chamber. When the engine is running, the linear solenoid is controlled so that the hydraulic pressure adjusted by the hydraulic control valve is introduced into the hydraulic chamber. By this introduction, the ring gear receives the hydraulic pressure in the axial direction of the cam shaft, and moves appropriately. At this time, due to the presence of the helical spline, the rotational phase of the pulley and the cam shaft drivingly connected to the engine is changed, and as a result, the opening / closing timing of the valve is adjusted.

[0004]

However, in the above-mentioned prior art, chips generated between or near the main hole and the oil filter during machining of the engine may be mixed in the hydraulic oil. In this case, the foreign matter may be accumulated in the gap between the outer circumference of the sleeve and the inner surface of the housing at the supply port portion. This phenomenon can occur mainly when the spool is held in the intermediate position. Then, once foreign matter has accumulated on this portion, when a large amount of hydraulic oil flows along with the next movement of the spool, the foreign matter also flows with the large amount of hydraulic oil. As a result, hydraulic oil containing foreign matter may flow inside the spool of the valve and eventually toward the valve timing mechanism (hydraulic chamber). As a result, foreign matter may be caught between the spool and the valve sleeve or may enter the valve timing mechanism, resulting in malfunction of the hydraulic control valve and malfunction of the valve timing mechanism.

The present invention has been made in view of the above-mentioned circumstances, and an object thereof is a hydraulic control for variable valve timing for controlling the pressure of hydraulic oil introduced from the oil pump to the variable valve timing mechanism. Even if foreign matter such as chips exists on the upstream side of the valve,
A hydraulic control for variable valve timing, which can prevent the foreign matter from flowing into the control valve or the valve timing mechanism, and thus can avoid malfunction of the control valve and the valve timing mechanism due to the intrusion of the foreign matter. To provide a valve.

[0006]

In order to achieve the above object, in the present invention, the rotational phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine is changed by utilizing the hydraulic pressure of hydraulic oil. Between a valve timing mechanism that adjusts the opening / closing timing of a valve driven by a camshaft, and an oil pump that is drivingly connected to the internal combustion engine and that pressurizes the hydraulic oil and discharges it to the valve timing mechanism. A housing provided with the housing, a sleeve accommodated inside the housing, and a spool slidably provided inside the sleeve and moved by an actuator, and to which hydraulic oil from the oil pump is supplied. It has a supply port and a discharge port for discharging the hydraulic oil to the valve timing mechanism, and is used for controlling the actuator. A hydraulic control valve for controlling the hydraulic pressure from the discharge port by adjusting the area of the supply port and the discharge port, and opening at the supply port in at least one of the sleeve and the housing. With a recess,
The gist of the present invention is that foreign matters in the hydraulic oil are accommodated and held by the recesses.

[0007]

According to the above construction, the valve timing mechanism changes the rotational phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine by utilizing the hydraulic pressure of the hydraulic oil, and the camshaft drives the camshaft. The opening / closing timing of the valve is adjusted. The hydraulic fluid is pressurized by an oil pump drivingly connected to the internal combustion engine and discharged to the valve timing mechanism. The hydraulic oil from the oil pump is supplied to the supply port of the hydraulic control valve provided between the valve timing mechanism and the oil pump, and the hydraulic oil is discharged from the discharge port to the valve timing mechanism. In this hydraulic control valve, the spool is slidably provided inside the sleeve in the housing and is moved by an actuator to adjust its position. By this adjustment, the areas of the supply port and the discharge port are adjusted and the hydraulic pressure from the discharge port is controlled.

Here, even if foreign matter such as chips is mixed in the hydraulic oil, the foreign matter is provided in at least one of the sleeve and the housing, and is accommodated and held in the concave portion opening to the supply port. To be done. Therefore, even if the spool moves, the foreign matter contained and held in the recess does not enter the spool and does not enter between the sleeve and the spool.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the variable valve timing hydraulic control valve according to the present invention will be described in detail below with reference to the drawings.

FIG. 3 is a diagram schematically showing a hydraulic oil circuit of an engine including a variable valve timing mechanism and a hydraulic control valve in this embodiment. The hydraulic oil circuit is the oil pan 4
2, an oil pump 41, an oil filter 43, a valve mechanism, a crank mechanism, a linear solenoid type hydraulic control valve (hereinafter, simply referred to as OCV) 44, a variable valve timing actuator (VVT actuator) 48 constituting a variable valve timing mechanism, and It is composed of various oil passages connecting these.

The individual elements will be described in detail below. The camshaft 1 is provided to drive an intake valve or an exhaust valve of an engine (not shown),
The journal 2 is rotatably supported between the bearing portion 4 of the cylinder head 3 and the bearing cap 5.
The journal 2 is formed with two journal grooves 6 and 7 extending along the outer circumference thereof. Further, the cylinder head 3 is formed with a first head oil passage 8 and a second head oil passage 9 for guiding hydraulic oil to the respective journal grooves 6, 7 and the journal 2.

One end of each head oil passage 8 and 9 is connected to an OCV 44, and this OCV 44 is connected to an oil pan 43 via an oil filter 43, an oil pump 41, and an oil strainer 45. Oil pump 41
Is connected to the engine, and pumps and discharges the hydraulic oil in the oil pan 41 through the oil strainer 45 in conjunction with the operation of the engine. Hydraulic oil is oil filter 4
After passing 3, the OCV 44 is operated to supply the head oil passages 8 and 9 with a predetermined pressure to the journal grooves 6 and 7 and the journal 2. The supply of hydraulic oil to the head oil passages 8 and 9 can be arbitrarily adjusted by the OCV 44. The detailed configuration of the OCV 44 will be described later.

Further, the oil filter 43 and the OCV 4
4 is formed such that a part of the main oil passage 46 branches off, and the branched part of this oil passage 46 lubricates the engine body including a valve mechanism, a crank mechanism and the like. It is connected to the system.

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

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

A ring gear 25 is interposed between the timing pulley housing 10 and the cam shaft 1, and the ring gear 25 connects the two 10, 10. 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.
It is housed 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 teeth 25 on the inner circumference of the ring gear 25
a is the outer tooth 22b of the inner cap 22 and the ring gear 2
Teeth 25b on the outer circumference of 5 mesh with inner 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 also integrally rotated with the timing pulley housing 10. It Further, both of these teeth 25a and 25b are helical teeth. Therefore, when the ring gear 25 is moved in the axial direction, the camshaft 1 is moved to the timing pulley housing 1.
It is designed to rotate relative to zero.

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

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 the hydraulic pressure of the working oil to the first hydraulic chamber 26. The tip end side of the shaft oil passage 28 communicates with the first hydraulic chamber 26 through the center hole 23a of the hollow bolt 23. Further, the base end side 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 the hydraulic pressure of the hydraulic oil to the second hydraulic chamber 27, the second shaft oil passage 3 is formed in the camshaft 1 so as to extend in parallel with the first shaft oil passage 28.
0 is formed. Further, at a position near the tip of the camshaft 1, one peripheral groove 31 is formed 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 that connects the circumferential groove 31 and the second hydraulic chamber 27 to each other is formed in a part of 4. The base end side of the second shaft oil passage 30 communicates with the journal groove 7. In addition, in the second hydraulic chamber 27, a spring 33 is interposed between the ring gear 25 and the pulley body 11 to urge the ring gear 25 to return to the initial position (retard position) shown in FIG. Has been done.

Then, as shown in FIG. 4, while 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 causes the journal groove 6 and the oil hole 2 to move.
The oil 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. By applying this hydraulic pressure 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, and the camshaft 1 is twisted. As a result, the camshaft 1 and the timing pulley housing 10
The relative position in the rotation direction with respect to is changed, 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 operation oil is supplied to the second head oil passage 9 by the OCV 44, and at the same time the first head oil passage 8 is opened to the oil pan 42, so that the operation is performed. 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 peripheral groove 31, and the oil hole 32. By applying this hydraulic pressure to the other end of the ring gear 25, the ring gear 25 is rotated while being moved in the axial direction against the hydraulic pressure in the first hydraulic chamber 26, and the camshaft 1 is rotated in the opposite direction to the above. A twist is added. As a result, the relative position of the camshaft 1 and the timing pulley housing 10 in the rotational direction is changed, and the operation timing of the intake valve or the exhaust valve is delayed, for example.

In this embodiment, when the OCV 44 stops the supply of hydraulic oil to both head oil passages 8 and 9, the ring gear 25 returns 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. Further, in this embodiment, it is possible to move the ring gear 25 in the axial direction and hold it at an arbitrary position by adjusting the balance of the hydraulic pressure supplied to the hydraulic chambers 26, 27 by the OCV 44.

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 to generate the ring gear 25.
It is for switching the stop position of. As shown in FIGS. 1 to 3, the OCV 44 includes a housing 50, a sleeve 51, a spool 52, and a solenoid 53 as an actuator. Sleeve 51 is housing 50
Accommodated in the accommodation space 50a of the supply port 54, the first
Discharge port 55, second discharge port 56, first drain port 57, and second drain port 58. The supply port 54 is connected to the oil pump 41 and constitutes a supply port in this embodiment. Further, the first discharge port 55 is connected to the first head oil passage 8, and the second discharge port 56 is connected to the second head oil passage 9. Both of these discharge ports 55 and 56 form the discharge port in this embodiment. Further, the first drain port 57 and the second drain port 58 are connected to the oil pan 42.

The spool 52 is arranged in the sleeve 51 so as to be slidable in the front-rear direction (left-right direction in FIG. 3). On the outer circumference of the spool 52, there are three annular recesses 6
1, 60 and 59 are formed so as to be separated from each other in the front-rear direction.

A solenoid 53 is provided in the rear half of the OCV 44 (right side in the figure), and the spool 52 is moved depending on whether or not the solenoid 53 is excited. The solenoid 53 is duty-controlled by an electronic control unit (hereinafter, simply referred to as “ECU”) 71. That is, the solenoid 53 may or may not be excited depending on the presence / absence of current supplied to itself. Then, the spool 52 reciprocates in the sleeve 51 according to its excited state. More specifically, the spool 52 is held at the position shown in FIG. 5 by the urging force of the spring 62 housed in the front end portion of the sleeve 51 when the solenoid 53 is not excited (for example, duty ratio = 0%). On the other hand, when the solenoid 53 is excited (for example, duty ratio = 100%), the spring 6
It moves forward to the position shown in FIG. 4 against the biasing force of 2. When the solenoid 53 repeats excitation and non-excitation in a short cycle (for example, duty ratio = 5).
0%), an appropriate intermediate position, that is, the position shown in FIG.

More specifically, the solenoid 5 will be described.
3 is de-excited (duty ratio = 0%), spool 5
When 2 is retracted to the position of FIG. 5, the main oil passage 46, the supply port 54, the central annular recess 60, and the second discharge port 56 are in communication. Further, the first discharge port 55, the front annular recess 61, and the first drain port 57 communicate with each other.
Then, the hydraulic 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, the hydraulic oil from the first head oil passage 8 is discharged from the first discharge port 55 through the first drain port 57 to the oil pan 42.

When the spool 52 advances to the position shown in FIG. 4 due to the excitation of the solenoid 53 (duty ratio = 100%), the main oil passage 46 and the supply port 5 are moved.
4, the central annular recess 60 and the first discharge port 55 communicate with each other. Further, the second discharge port 56, the annular recess 59 on the rear side, and the second drain port 58 communicate with each other. Then
The hydraulic oil from the oil pump 41 is supplied to the first discharge port 5
5 is supplied to the first head oil passage 8. Meanwhile, the second
Of the hydraulic oil from the head oil passage 9 of the second discharge port 56
Is discharged to the oil pan 42 through the second drain port 58.

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

That is, the spool 52 moves in the front-rear direction according to the duty ratio at that time to switch the flow of hydraulic oil. Then, when the duty ratio is around 50% (40% to 60%), the spool 52 is held at the intermediate position, and the amount of hydraulic oil supplied to the VVT actuator 48 becomes substantially "0".

The solenoid 53 of the OCV 44 is an EC
The drive is controlled by U71. Specifically, the ECU 71
Various sensors are connected to the input side of. Also, E
The solenoid 53 of the OCV 44 is provided on the output side of the CU 71.
Is connected. Then, the ECU 71 calculates 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.

In the present embodiment, as shown in FIGS. 1 and 2, the sleeve 51 of the OCV 44 is provided with a foreign matter accommodating recess 65 that opens to the supply port 54. That is, the accommodating concave portion 65 is formed at one location along the outer peripheral portion in the substantially central portion of the sleeve 51. Strictly speaking, the foreign matter accommodating concave portion 65 is constituted by an inner wall surface of the housing 50 and a notch formed on the outer circumference of the sleeve 51. The shape is such that, for example, one end opens to the supply port 54 and the other end extends along the flow direction of the hydraulic oil, that is, toward the first and second discharge ports 55 and 56. It is shaped like a heart. Further, the size of the foreign matter storage recess 65 is sufficient to accommodate the foreign matter that may occur in the main oil passage 46, and is formed to the minimum necessary extent.

Next, the operation and effect of this embodiment constructed as described above will be described. Note that the OC by the ECU 71
The operation when the valve timing is controlled to the advanced side or the retarded side by the control of V44 has already been described in the above-mentioned constituent parts, and therefore the description thereof is omitted here.

First, by driving the engine,
The oil pump 41 is driven. Along with this driving, hydraulic oil is sucked up from the oil pan 42 through the oil strainer 45. After passing through the oil filter 43, a part of the operating oil is supplied to the engine main body lubricating system through the main oil passage 46. Therefore, the valve mechanism and the crank mechanism are lubricated by the supplied hydraulic oil.

The other part of the hydraulic oil that has passed through the oil filter 43 is introduced into the OCV 44. here,
When the spool 52 is held at the intermediate position shown in FIG. 3, the central annular recess 60 is closed on the outlet side. That is, the hydraulic oil introduced from the supply port 54 is
It is blocked in the central annular recess 60, and is hardly discharged from either of the first and second discharge ports 55, 56. At this time, according to the conventional technique, when foreign matter such as chips is mixed in the hydraulic oil, the foreign matter is removed from the sleeve 51.
And may be deposited between the housing 50. However, in the present embodiment, a portion of the outer periphery of the sleeve 51 where foreign matter is most likely to be deposited, that is, a portion that opens to the supply port 54 at the substantially center of the sleeve 51
The foreign matter accommodation recess 65 having the above-described configuration is formed. For this reason, the foreign matter in the hydraulic oil will be contaminated by the foreign matter containing recess 6
5 is accommodated and held in the inside. Therefore, at the next opportunity, spool 5
2 moves to the advance side or the retard side and a large amount of hydraulic oil is VVT
Even if the foreign matter flows to the actuator 48, the foreign matter does not flow out from the foreign matter accommodating recess 65. As a result, the operation of the OCV 44 or the VVT actuator 48 is not locked by the foreign matter, and it is possible to prevent these malfunctions from occurring.

Further, in the present embodiment, the shape of the foreign matter accommodating concave portion 65 is such that one end is opened to the supply port 54 and
The other end is formed in a heart shape so as to extend along the flow direction of the hydraulic oil, that is, toward the first and second discharge ports 55, 56. Therefore, the foreign matter in the hydraulic oil is accommodated in the accommodation recess 65 along with the flow of the hydraulic oil.
It is housed and retained within. That is, regardless of whether the spool 52 moves from the state of FIG. 3 to the advance side or the retard side, the foreign matter surely enters the concave portion 65 and is mixed. As a result, the certainty of the above effect can be further enhanced.

Further, in this embodiment, the foreign matter accommodating recess 65 is formed.
Is provided on the outer circumference of the sleeve 51. For this reason,
When forming the concave portion 65, the concave portion 65 can be easily formed by a cutting process from the outside of the sleeve 51, and thus a rise in manufacturing cost can be suppressed.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above-described embodiment, the foreign matter containing recess 65 is formed in the sleeve 5.
However, it may be provided on the housing recess 50a side of the housing 50. In this case, when the housing 50 is manufactured, the housing 50
Each of the oil passages inside must be formed by a drill, and at this time, the guide recess of the drill must also be originally formed. Therefore, the guide concave portion can be adopted as the foreign matter accommodating concave portion on the housing 50 side,
In such a case, it is possible to omit the trouble of separately forming the foreign matter accommodation recess.

Further, foreign matter containing recesses may be formed in both the containing recess 50a of the housing 50 and the sleeve 52. (2) In the above embodiment, the ring gear 25 and the pulley body 1
Although the structure in which the spring 33 is interposed between the spring 33 and 1 is adopted, the spring 33 may be omitted.

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

(4) In the above embodiment, a modulation valve as a constant pressure valve may be provided between the oil pump 41 and the OCV 44. With such a configuration, the hydraulic pressure supplied to the VVT actuator 48 becomes approximately a predetermined value, so that the variable responsiveness, controllability, and durability can be improved. The technical idea which is not described in the claims of the claims and can be grasped from the above-mentioned embodiment will be described below together with the effect thereof.

(A) In the hydraulic control valve for variable valve timing according to claim 1, the recess is formed along the flow direction of the hydraulic oil. With such a configuration, the foreign matter in the hydraulic oil is housed and held in the recess along with the flow of the hydraulic oil, and the certainty of the effect of claim 1 can be further enhanced.

(B) In the hydraulic control valve for variable valve timing according to claim 1 or the above-mentioned appendix (a), the recess is formed along the outer circumference of the sleeve. With such a configuration, it is possible to easily form the concave portion by cutting from the outside of the sleeve, and thus it is possible to suppress an increase in manufacturing cost.

[0043]

As described in detail above, according to the present invention,
In the variable valve timing hydraulic control valve for controlling the pressure of the hydraulic oil introduced from the oil pump to the variable valve timing mechanism, even if foreign matter such as chips exists on the upstream side of the variable valve timing control system, the foreign matter is controlled. It is possible to suppress the inflow into the valve and the valve timing mechanism, and thus it is possible to avoid the malfunction of the control valve and the valve timing mechanism due to the invasion of foreign matter.

[Brief description of drawings]

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

FIG. 2 is a sectional view taken along line AA of FIG. 1 in 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.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Camshaft, 41 ... Oil pump, 44 ... OCV as a hydraulic control valve, 48 ... VVT actuator which comprises a valve timing mechanism, 50 ... Housing, 51
... Sleeve, 52 ... Spool, 53 ... Solenoid as actuator, 54 ... Supply port constituting supply target port, 55 ... First discharge port constituting discharge port, 56 ...
Second discharge port constituting discharge port, 65 ... Foreign matter accommodating recess.

Claims (1)

[Claims] 1. A valve timing mechanism for adjusting the opening / closing timing of a valve driven by the camshaft by changing the rotational phase of the camshaft with respect to the rotation of the crankshaft of the internal combustion engine using the hydraulic pressure of hydraulic oil. And a housing that is drive-connected to the internal combustion engine and that is provided between an oil pump that pressurizes the hydraulic oil and discharges the hydraulic oil to the valve timing mechanism, and a sleeve housed inside the housing, A supply port, which is provided slidably inside the sleeve and is moved by an actuator, is supplied with hydraulic oil from the oil pump and discharges the hydraulic oil to the valve timing mechanism. An outlet is provided, and by controlling the actuator, the areas of the supply target port and the discharge port are adjusted to A hydraulic control valve for controlling the hydraulic pressure in at least one of said sleeve and said housing,
A hydraulic control valve for variable valve timing, characterized in that a recess opening to the supply port is provided so that foreign matter in the hydraulic oil is accommodated and held by the recess.