JP2000130115A - Variable cam phase device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable cam phase device capable of avoiding the increase of oil consumption and the deterioration of exhaust gas caused by oil mist, by preventing the situation in which oil discharged from an oil control valve(OCV) from falling to a rotating cam shaft. SOLUTION: Operating oil to a hydraulic actuator of a variable phase means for varying the phase of a cam shaft 3 is controlled by a hydraulic oil switching means (an oil control valve) 45 arranged just over the cam shaft 3, and drain passages 62 are so arranged that hydraulic oil from the hydraulic actuator, to be discharged from the hydraulic oil switching means 45 may avoid the cam shaft 3, and therefore, the hydraulic oil is prevented from falling to the rotating cam shaft 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable cam phase device for adjusting the opening / closing timing of an intake valve and an exhaust valve of an engine by hydraulic pressure, and more particularly, to the structure of an oil control valve (hereinafter referred to as OCV) for controlling hydraulic pressure. It is about.

[0002]

2. Description of the Related Art For example, as described in Japanese Patent Application Laid-Open No. 9-60508, this type of cam phase changing device is provided on a cam sprocket that is driven to rotate by a crankshaft, and a vane rotor disposed inside the cam sprocket. It is linked to The oil discharged from the oil pump of the engine according to the switching of the OCV is selectively introduced into the advance hydraulic chamber and the retard hydraulic chamber provided on both sides of the vane rotor as operating oil, and the hydraulic pressure causes the cam to move together with the vane rotor. The phase of the shaft is changed to the advance side or the retard side, and the opening / closing timing of the intake / exhaust valve is adjusted. In order to secure the rotation responsiveness of the vane rotor, it is desirable to minimize the length of the hydraulic pipeline from the OCV to the variable cam phase device. Therefore, as shown in FIG. It is installed in.

[0003]

However, when the OCV 101 is installed as described above, the OCV 101
There is a problem that oil mist is generated by the oil discharged from the oil. More specifically, when oil is introduced into one of the advance hydraulic chamber and the retard hydraulic chamber, the oil in the hydraulic chamber on the opposite side becomes OC with rotation of the vane rotor.
Returned to V101, drain port 10 of OCV101
After that, the air is discharged from the drain passage 104 to the cylinder head 105 through the third passage 3. As described above, since the OCV 101 is located immediately above the camshaft 102, the oil from the drain passage 104 removes the oil from the rotating camshaft 1 as shown by the arrow.
02, oil mist is generated in the rocker cover, and as a result, various problems such as an increase in oil consumption and deterioration of exhaust gas may be caused.
Further, there is a possibility that a problem that accurate control is hindered due to air being mixed into the oil.

An object of the present invention is to prevent oil discharged from an OCV from falling on a rotating camshaft, and to prevent various problems such as an increase in oil consumption due to generation of oil mist and deterioration of exhaust gas. An object of the present invention is to provide a cam phase variable device which can be avoided beforehand.

[0005]

In order to achieve the above object, according to the present invention, a relative rotation angle between a power transmission member and a camshaft which rotates synchronously with respect to a crankshaft is adjusted by a phase variable means provided with a hydraulic actuator. It is possible to control the hydraulic pressure of the hydraulic actuator of the phase changing means by switching the hydraulic oil from the hydraulic oil supply source by the hydraulic oil switching means disposed immediately above the camshaft, and from the hydraulic actuator discharged from the hydraulic oil switching means The drain passage is arranged so that the hydraulic oil of the above can avoid the camshaft. Accordingly, the hydraulic oil from the hydraulic oil supply source is supplied to the hydraulic actuator of the phase variable means in accordance with the switching of the hydraulic oil switching means, and the phase of the camshaft with respect to the power transmission member is adjusted by the phase variable means. At this time, the hydraulic oil returned from the hydraulic actuator is guided by the hydraulic oil switching means immediately above the camshaft to the drain passage so as to avoid the camshaft and is discharged, so that the hydraulic oil falls on the rotating camshaft. The situation is prevented.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment A first embodiment in which the present invention is embodied in a variable cam phase device for adjusting the opening / closing timing of an intake valve will be described. As shown in FIGS. 1 and 2, a camshaft 3 on the intake side is supported by a bearing 2 of a cylinder head 1 of the engine so as to be rotatable and immovable in an axial direction. Is driven to open and close. A timing pulley 4 as a power transmission member is rotatably fitted to the front end of the camshaft 3, and the timing pulley 4 is connected to a crankshaft (not shown) via a timing belt 5, and about the axis of the camshaft 3. It is rotationally driven at a reduced speed of 1/2 in the direction of the arrow in FIG. Although not shown, an exhaust-side timing pulley is also connected to the timing belt 5, so that the exhaust valve is opened and closed by an exhaust-side camshaft.

[0007] On one side of the timing pulley 4, an actuator section 6 as a phase changing means is provided. Housing 7 and front cover 8 of actuator section 6
Is fixed to one side of the timing pulley 4 and has a substantially cross-shaped hydraulic chamber 1 centered on the axis of the camshaft 3.
0 is formed. The vane rotor 1 is provided in the hydraulic chamber 10.
The center portion is fixed to the front end of the camshaft 3 by a cam bolt 14. The head 14 a of the cam bolt 14 is located in an oil distribution chamber 15 formed in the vane rotor 12, and the distribution chamber 15 is closed by a plug 16.

The vane rotor 12 has a substantially cross shape corresponding to the hydraulic chamber 10, and includes four vanes 12a at 90-degree intervals.
On both sides of the cylinder, a retard hydraulic chamber 1 as a hydraulic actuator
7a and an advanced hydraulic chamber 17b are formed. The vane rotor 12 has the most retarded position where the volume of the retard hydraulic chamber 17a is maximized as shown by a solid line in FIG. 2 and the most advanced position where the volume of the advance hydraulic chamber 17b is maximized as shown by a virtual line. , And can rotate around the axis of the camshaft 3.

On the other hand, the vane rotor 12 has an oil distribution chamber 15
Are formed radially around the center, one end of each advance introduction oil passage 23 opens into the oil distribution chamber 15, and the other end opens into the advance hydraulic chamber 17b. ing. The oil distribution chamber 15 has an oil groove formed on the entire outer periphery of the camshaft 3 via a through oil passage 24 penetrating the cam bolt 14, a first oil passage 25 and a second oil passage 26 that are continuous from the through oil passage 24. 27.

The vane rotor 12 has four radially-introduced oil passages 29 formed radially, and one end of each of the retarded-introduction oil passages 29 opens into the retard hydraulic chamber 17a. The other end of each retard introduction oil passage 29 is connected to a third oil passage 30 and a fourth oil passage 31 respectively.
Through the oil groove 32 formed on the entire outer periphery of the camshaft 3. As shown in FIGS. 1 and 3,
The bearing portion 2 includes a lower holder 41 integrally formed on the cylinder head 1 and an upper holder 42 fixed on the lower holder 41 with a bolt (not shown).
The camshaft 3 is held in a bearing hole 43 formed between the holders 41 and 42. As shown in FIG. 1, the upper holder 42 extends rearward from the lower holder 41, and a part of a lower surface 42 a thereof faces the cylinder head 1 at a predetermined interval.

As shown in FIG. 3, a sliding hole 44 is formed in the upper holder 42 so as to be orthogonal to the axis of the camshaft 3, and in the sliding hole 44, the hydraulic oil is switched from the right in FIG. The sleeve 46 of the OCV 45 as a means is inserted and fixed, and the O-ring 47 keeps oil tight.
A spool 48 is inserted into the sleeve 46 so as to be slidable left and right. An advancing drain cavity 51, a supply cavity 52, and a retarding drain cavity 53 are provided around the outer periphery of the spool 48 at predetermined intervals from the left side. Is formed.

The spool 48 is constantly biased to the right by a compression spring 49 in the sleeve 46, and is driven to the left by a solenoid 50 connected to the right end. The biasing force of the compression spring 49 and the driving force of the solenoid 50 Can be held at any balanced position. Solenoid 50 controls fuel injection and ignition timing of the engine (not shown).
The excitation state is controlled by a CU (engine control unit).

A pump port 54 is formed in the sleeve 46 so as to correspond to the supply cavity 52, and the pump port 54 opens downward from the outer peripheral surface of the spool 48. The opening of the pump port 54 is connected to an oil pump (not shown) of the engine via a pump oil passage 55 formed in the upper holder 42.
The actuator unit 6 operates using engine oil discharged from the oil pump as hydraulic oil.

An advance supply port 56 is formed in the sleeve 46 so as to be located between the supply cavity 52 of the spool 48 and the advance drain cavity 51. Similarly, the supply cavity 52 of the spool 48 and the retard drain A retard supply port 57 is formed to be located between the cavity 53 and the supply port 56, 57, which opens upward from the outer peripheral surface of the spool 48. Lead angle supply port 56
Opening communicates with the above-described advance-side oil groove 27 via an advance-supply oil passage 58 formed in the upper holder 42,
The opening of the retard supply port 57 is connected to the oil groove 32 on the retard side through a retard supply oil passage 59 formed in the upper holder 42.
Is in communication with

In the sleeve 46, an advance drain port 60 is formed corresponding to the advance drain cavity 51 of the spool 48, and a retard drain port 61 is formed corresponding to the retard drain cavity 53. Drain port 6
Reference numerals 0 and 61 open downward from the outer peripheral surface of the spool 48. The upper holder 42 has two drain ports 60, 6
A pair of drain passages 62 are formed corresponding to the openings of the first and second openings.
0, 61, and the lower end is the lower surface 42a of the upper holder 42.
It is open to. In the present embodiment, as is apparent from FIG. 3, the two drain passages 62 are arranged in a substantially C-shape so as to avoid the camshaft 3 located therebetween, and as a result, the lower side of the two drain passages 62 is formed. Are located on both sides of the camshaft 3.

The sleeve 46 has air vent holes 63 corresponding to the distal end and the proximal end of the spool 48.
Air is supplied and exhausted through these air vent holes 63 so that the air accumulated on the distal end side and the proximal end side does not hinder the sliding of the spool 48. Spool 46 shown in FIG.
Is moved to the right, the pump port 54 communicates with the retard supply port 57 via the supply cavity 52, and the advance supply port 56 communicates with the advance drain port 60 via the advance drain cavity 51. I do. Although not shown, in the advanced position where the spool 46 has moved to the left,
The pump port 54 communicates with the advance supply port 56 via the supply cavity 52, and the retard supply port 57 communicates with the retard drain port 61 via the retard drain cavity 53. Further, in the neutral position where the spool 46 is moved to the center, all ports are not connected to each other,
Blocked by 6.

A rocker cover (not shown) is fixed to the upper surface of the cylinder head 1, and the members such as the camshaft 3 and the OCV 45 are concealed from the outside by the rocker cover. OC
The oil discharged from the V45 is prevented from scattering outside. Next, the phase control of the camshaft 3 by the cam phase variable device configured as described above will be described.

During operation of the engine, the ECU controls the intake camshaft 3 based on the engine speed and load.
The optimal phase (opening / closing timing of the intake valve)
The duty ratio of the solenoid 50 of the OCV 45 is controlled, and the actual phase of the camshaft 3 is adjusted to the advance side or the retard side. That is, when the duty ratio is controlled in the decreasing direction and the excitation of the solenoid 50 is weakened, the spool 48 moves to the right retard position by the compression spring 49 as shown in FIG. , Pump oil passage 55, pump port 54, retard supply port 57, retard supply oil passage 59, oil groove 32, fourth oil passage 31, third oil passage 30, and retard introduction oil passage 29. Square hydraulic chamber 17a
Introduced within. Therefore, the vane rotor 12 rotates to the retard side by the hydraulic pressure, and the phase of the camshaft 3 is also adjusted to the retard side. Further, with the rotation to the retard side, the oil in the advance hydraulic chamber 17b is discharged into the advance introduction oil passage 23, the oil distribution chamber 15, the through oil passage 24, the first oil passage 25, and the second oil. Road 26,
Oil groove 27, advance supply path 58, advance supply port 56,
It is discharged onto the cylinder head 4 via the advance drain port 60 and the drain passage 62.

When the duty ratio is controlled in the increasing direction to increase the excitation of the solenoid 50, the spool 48 moves to the left advance position against the compression spring 49, and the oil from the oil pump is Pump oil passage 55, pump port 54, advance supply port 56, advance supply passage 58, oil groove 27, second oil passage 26, first oil passage 25, through oil passage 24,
The vane rotor 1 is introduced into each advance hydraulic chamber 17b through the oil distribution chamber 15 and the advance introduction oil passage 23,
2, the phase of the camshaft 3 is adjusted to the retard side.
The oil in the retard hydraulic chamber 17a is supplied to the retard introduction oil passage 29, the third oil passage 30, the fourth oil passage 31, the oil groove 32, the retard supply oil passage 59, the retard supply port 57, and the retard drain port. 61,
Then, it is discharged onto the cylinder head 4 through the drain passage 62.

When the spool 48 is moved to the neutral position when the camshaft 3 reaches the target phase, the advance supply port 56 and the retard supply port 57 are closed, and the camshaft is moved to the phase position. 3 can be held. Although the phase control of the camshaft 3 has been described above, when the oil is discharged from the hydraulic chambers 17a and 17b with the switching operation of the OCV 45 as described above, the lower opening of the drain passage 62 is connected to the camshaft. 3, the oil is discharged onto the cylinder head 1 directly from both sides while avoiding the camshaft 3 without falling on the rotating camshaft 3 as shown by arrows in FIG. You. Accordingly, generation of oil mist due to agitation in the camshaft 3 is prevented, and various problems such as an increase in oil consumption, deterioration of exhaust gas, and deterioration of phase controllability due to air mixing in oil are avoided. be able to.

Second Embodiment Next, a second embodiment in which the present invention is embodied in another cam phase changing device will be described. The variable cam phase device of the present embodiment is different from the first embodiment in the configuration of the drain passage 71, and the other configurations are completely the same. Therefore, portions having the same configuration are denoted by the same reference numerals, description thereof will be omitted, and differences will be mainly described.

As shown in FIG. 4, the drain passage 71 of this embodiment is arranged vertically downward from the openings of both drain ports 60 and 61, similarly to the drain passage 104 of the prior art shown in FIG. Have been. Between the two drain passages 71,
A support seat 72 located just above the camshaft 3 is formed, and a guide plate 73 is fixed to the support seat 72 with a bolt (not shown). The guide plate 73 is formed to be curved at a slight interval along the upper half circumference of the camshaft 3, and its front-rear width (the direction perpendicular to the paper surface in FIG. 4) extends over the entire front-rear dimension of the drain passage 71. The upper half circumference of the camshaft 3 is covered by the guide plate 73, and the lower openings of both the drain passages 71 are located on both sides of the camshaft 3 as in the first embodiment.

Since the variable cam phase device of this embodiment is constructed as described above, the oil discharged from the drain ports 60 and 61 in accordance with the switching operation of the OCV 45 causes the oil discharged from the drain passages 71 and 61 as shown by arrows. Guide plate 7 while flowing inside
3 and is discharged directly onto the cylinder head 1 from both sides of the camshaft 3 without falling on the rotating camshaft 3. Accordingly, similarly to the first embodiment, generation of oil mist due to agitation in the camshaft 3 is prevented, and an increase in oil consumption, deterioration of exhaust gas, and deterioration of phase controllability due to mixing of air into oil. Various inconveniences can be avoided beforehand.

The description of the embodiment has been completed above, but the embodiments of the present invention are not limited to this embodiment. For example,
In the first embodiment and the second embodiment, the cam phase variable device in which the internal vane rotor 12 is rotated by hydraulic pressure is embodied. However, the phase of the camshaft 3 is adjusted using hydraulic pressure, and The operating principle is not limited as long as the OCV 45 for switching the oil pressure is disposed immediately above the camshaft 3. Therefore, for example, the present invention may be embodied in a cam phase variable device of a type in which the helical gear is operated by hydraulic pressure along the axis of the camshaft 3 to adjust the phase.

In the first embodiment, the drain passages 62 are arranged obliquely in a substantially C-shape, and in the second embodiment, the guide plates 73 are provided so that the lower openings of the drain passages 62 and 71 are formed. Are located on both sides of the camshaft 3,
In short, it is only necessary to prevent the oil from the drain ports 60 and 61 from falling on the camshaft 3, and the shape and configuration of the drain passage may be variously changed.

[0026]

As described above, according to the variable cam phase device of the present invention, the hydraulic oil discharged from the hydraulic oil switching means is guided through the drain passage to prevent the oil from falling on the rotating camshaft. As a result, generation of oil mist due to agitation in the camshaft is prevented, and various problems such as an increase in oil consumption, deterioration of exhaust gas, and deterioration in phase controllability due to air mixing in oil are prevented. Can be avoided.

[Brief description of the drawings]

FIG. 1 shows a cam phase changing device according to a first embodiment;
FIG. 2 is a sectional view taken along line -I.

FIG. 2 is a cross-sectional view showing a cam phase changing device.

FIG. 3 is a sectional view taken along line III-III of FIG. 1, showing a shape of a drain passage.

FIG. 4 is a sectional view showing the shape of a drain passage in the variable cam phase device of the second embodiment.

FIG. 5 is a cross-sectional view showing a shape of a drain passage in a conventional cam phase changing device.

[Explanation of symbols]

 3 Camshaft 4 Timing Pulley (Power Transmission Member) 6 Actuator (Phase Variable Means) 17a Advanced Hydraulic Chamber (Hydraulic Actuator) 17b Delay Angle Hydraulic Chamber (Hydraulic Actuator) 45 OCV (Hydraulic Oil Switching Means) 62, 71 Drain Passage

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G016 AA08 AA12 AA19 BA02 BA05 BA22 BA28 BA38 CA04 CA13 CA16 CA24 CA27 CA33 CA36 CA40 CA45 CA48 CA57 CA59 DA04 DA06 DA22 GA00

Claims (1)

[Claims] A power transmission member that rotates in synchronization with a crankshaft; a camshaft having a cam that opens and closes an intake valve or an exhaust valve; and adjusts a relative rotation angle between the power transmission member and the camshaft. A phase variable unit having a hydraulic actuator provided so as to be able to operate; a hydraulic oil supply source for supplying hydraulic oil to the hydraulic actuator of the phase variable unit; a hydraulic oil supply source disposed immediately above the camshaft; A hydraulic oil switching unit connected to an oil supply source for controlling a hydraulic pressure of the hydraulic actuator; and a hydraulic oil discharged from the hydraulic oil switching unit and arranged from the hydraulic actuator to avoid the camshaft. A variable cam phase device comprising: