JP3468280B2 - Variable cam phase device - Google Patents

Description

Detailed Description of the Invention

[0001]

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

[0002]

Related Background Art For example, as described in Japanese Patent Application Laid-Open No. 9-60508, a cam phase changing device of this type is provided on a cam sprocket that is rotationally driven by a crankshaft, and a vane rotor disposed inside the camshaft is used. It is linked to. Oil discharged from the oil pump of the engine is selectively introduced as working oil in accordance with OCV switching into the advance hydraulic chamber and the retard hydraulic chamber provided on both sides of the vane rotor, 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 rotational responsiveness of the vane rotor, it is desirable to shorten the hydraulic line length from the OCV to the cam phase varying device as much as possible. Therefore, as shown in FIG. 5, the OCV 101 is generally directly above the camshaft 102. 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. More specifically, when oil is introduced into either the advance hydraulic chamber or the retard hydraulic chamber, the oil in the hydraulic chamber on the opposite side is OC due to the rotation of the vane rotor.
Return to V101, OCV101 drain port 10
After that, the liquid is discharged from the drain passage 104 onto the cylinder head 105. As described above, since the OCV 101 is located right above the camshaft 102, the oil from the drain passage 104 is rotated by the rotating camshaft 1 as shown by the arrow.
02, the oil mist is generated in the rocker cover, which may lead to various problems such as an increase in oil consumption and deterioration of exhaust gas.
In addition, there is a possibility that air may be mixed into the oil, which may hinder accurate control.

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

[0005]

In order to achieve the above object, in the invention of claim 1, the relative rotation angle between the power transmission member that rotates synchronously with the crankshaft and the camshaft is variable by a phase provided with a hydraulic actuator. and adjustable by means controls the hydraulic pressure of the hydraulic actuator of the phase variable unit switches the operating fluid from the operating fluid supply source by the hydraulic fluid switching means disposed directly above the camshaft, de
Position the lower opening of the drain passage to the side of the camshaft.
The hydraulic oil from the hydraulic actuator.
I tried to discharge from the step through the drain passage . Therefore,
The hydraulic oil from the hydraulic oil supply source is supplied to the hydraulic actuator of the phase changing means according to the switching of the hydraulic oil switching means, and the phase changing means adjusts the phase of the camshaft with respect to the power transmission member. At this time, the hydraulic oil returned from the hydraulic actuator is guided to the drain passage from the hydraulic oil switching means directly above the camshaft, and is then moved to the side of the camshaft.
Since the oil is discharged from the lower opening of the drain passage located at, it is possible to prevent the hydraulic oil from falling on the rotating camshaft. In the invention of claim 2, the upper side of the camshaft
A guide plate is placed so as to cover half the circumference, and the drain
The lower opening of the passage is located on the side of the camshaft.
Therefore, when the hydraulic oil from the hydraulic oil switching means is rotating,
It is possible to prevent the situation of falling on the floor.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION [First Embodiment] A first embodiment in which the present invention is embodied in a cam phase varying device for adjusting the opening / closing timing of an intake valve will be described below. As shown in FIGS. 1 and 2, an intake side camshaft 3 is rotatably supported by a bearing portion 2 of a cylinder head 1 of an engine so as to be immovable in an axial direction, and each cylinder is rotated as the camshaft 3 rotates. The intake valve (not shown) is opened and closed. A timing pulley 4 as a power transmission member is rotatably fitted in the front end of the camshaft 3, and the timing pulley 4 is connected to a crankshaft (not shown) via a timing belt 5 so that the camshaft 3 is centered on the axis. It is decelerated by 1/2 in the direction of the arrow in FIG. 2 and is rotationally driven. Although not shown, a timing pulley on the exhaust side is also connected to the timing belt 5 so that the exhaust valve is opened and closed by a camshaft on the exhaust side.

An actuator portion 6 as a phase changing means is provided on one side surface of the timing pulley 4. Housing 7 and front cover 8 of actuator unit 6
Is fixed to one side surface of the timing pulley 4 and has a substantially cross-shaped hydraulic chamber 1 centered on the axial center of the camshaft 3 therein.
0 is formed. The vane rotor 1 is installed in the hydraulic chamber 10.
2 are arranged, and the central portion thereof is fixed to the front end of the cam shaft 3 by a cam bolt 14. The head portion 14 a of the cam bolt 14 is located inside 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 has four vanes 12a at 90-degree intervals.
The retarded hydraulic chambers 1 as hydraulic actuators are provided on both sides of the
7a and an advance 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 the solid line in FIG. 2 and the most advanced position where the volume of the advance hydraulic chamber 17b is maximized as shown by the phantom line. Between them can be rotated about the axis of the camshaft 3.

On the other hand, the vane rotor 12 has an oil distribution chamber 15
4 lead angle introduction oil passages 23 are formed radially, one end of each advance angle introduction oil passage 23 is opened in the oil distribution chamber 15, and the other end is opened in the advance angle hydraulic chamber 17b. ing. The oil distribution chamber 15 has an oil groove formed on the entire outer circumference 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 continuous from the through oil passage 24. It opens in 27.

Further, the vane rotor 12 is radially formed with four retarded angle introduction oil passages 29, and one end of each retarded angle introduction oil passage 29 opens into the retard angle hydraulic chamber 17a. The other end of each retarding oil passage 29 has a third oil passage 30 and a fourth oil passage 31 respectively.
Through an oil groove 32 formed on the entire outer circumference of the camshaft 3. As shown in FIGS. 1 and 3,
The bearing portion 2 is composed of a lower holder 41 integrally formed on the cylinder head 1 and an upper holder 42 fixed to the lower holder 41 with a bolt (not shown).
The cam shaft 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 with a predetermined space therebetween.

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 the hydraulic oil is switched from the right side in FIG. The sleeve 46 of the OCV 45 as a means is inserted and fixed, and the O-ring 47 keeps the oil tight.
A spool 48 is slidably inserted in the sleeve 46 to the left and right, and an advance drain cavity 51, a supply cavity 52, and a retard drain cavity 53 are provided on the outer circumference of the spool 48 from the left side over the entire circumference at predetermined intervals. Has been formed.

The spool 48 is constantly urged 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, so that the urging force of the compression spring 49 and the driving force of the solenoid 50 are combined. Can be held at any position in which they are balanced. The solenoid 50 controls the fuel injection and ignition timing of the engine and is not shown in the figure.
The excitation state is controlled by the 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, and as described later,
The actuator portion 6 operates by using the engine oil discharged from the oil pump as hydraulic oil.

An advance feed port 56 is formed in the sleeve 46 so as to be located between the feed cavity 52 of the spool 48 and the advance drain cavity 51. Similarly, the feed cavity 52 of the spool 48 and the retard drain are formed. A retarded angle supply port 57 is formed so as to be positioned between the cavity 53 and the cavity 53, and both supply ports 56, 57 are open upward from the outer peripheral surface of the spool 48. Advance supply port 56
Through the advance oil supply passage 58 formed in the upper holder 42 and communicates with the advance-side oil groove 27.
The opening of the retard angle supply port 57 is connected to the retard angle side oil groove 32 via the retard angle supply oil passage 59 formed in the upper holder 42.
Is in communication with.

An advance drain port 60 is formed in the sleeve 46 in correspondence with the advance drain cavity 51 of the spool 48, and a retard drain port 61 is formed in correspondence with the retard drain cavity 53. Drain port 6
0 and 61 open downward from the outer peripheral surface of the spool 48. The upper holder 42 has both drain ports 60, 6
A pair of drain passages 62 are formed so as to correspond to the openings of the drain port 1.
0, 61, and the lower end is the lower surface 42a of the upper holder 42.
It is open to. In this embodiment, as is clear from FIG. 3, both drain passages 62 are arranged so as to be inclined in a substantially C shape so as to avoid the camshaft 3 located therebetween, and as a result, the lower sides of both drain passages 62 are arranged. The openings are located on both sides of the camshaft 3.

The sleeve 46 is provided with air vent holes 63 corresponding to the front end side and the base end side of the spool 48,
Air is supplied and exhausted through these air vent holes 63 so that the air accumulated on the front end side and the base end side does not hinder the sliding of the spool 48. Spool 46 shown in FIG.
In the retard position 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. To do. Although not shown, at the advance position where the spool 46 moves 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 the ports do not communicate with each other and the spool 4
Blocked by 6.

A rocker cover (not shown) is fixed to the upper surface of the cylinder head 1, and the rocker cover hides members such as the camshaft 3 and the OCV 45 from the outside, and oils for lubricating the valve operating mechanism and as will be described later. To OC
The oil discharged from V45 is prevented from scattering outside. Next, the phase control of the camshaft 3 by the cam phase varying device configured as described above will be described.

During operation of the engine, the intake side camshaft 3 is controlled by the ECU on the basis of the engine speed, the load and the like.
Of the optimum phase (timing of opening and closing the intake valve) of
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 to decrease and the excitation of the solenoid 50 is weakened, as shown in FIG. 3, the compression spring 49 moves the spool 48 to the right retard position, and the oil from the oil pump is removed. , 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
Will be introduced in. Therefore, the vane rotor 12 is rotated 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 toward the retard side, the oil in the advance hydraulic chamber 17b is changed to 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 feed passage 58, advance feed port 56,
It is discharged onto the cylinder head 4 through the advance drain port 60 and the drain passage 62.

When the duty ratio is controlled to increase and the excitation of the solenoid 50 is strengthened, 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,
It is introduced into each advance angle hydraulic chamber 17b through the oil distribution chamber 15 and the advance angle introducing oil passage 23, and the vane rotor 1 is introduced by the oil pressure.
Along with 2, the phase of the camshaft 3 is adjusted to the retard side.
The oil in the retard hydraulic chamber 17a is 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,
And 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 brought to the phase position. Can hold 3. Although the phase control of the camshaft 3 is as described above, when the oil is discharged from the hydraulic chambers 17a and 17b in accordance with the switching operation of the OCV 45 as described above, the opening below the drain passage 62 is located in the camshaft. Since it is located on both sides of 3, the oil does not reach the rotating camshaft 3 and is discharged to the cylinder head 1 directly from both sides thereof, avoiding the camshaft 3 as shown by the arrow in FIG. It Therefore, 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 inclusion in oil are avoided in advance. be able to.

[Second Embodiment] Next, a second embodiment in which the present invention is embodied in another cam phase varying device will be described. The cam phase varying 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, the parts having the same structure are given the same member numbers, and the description thereof will be omitted. 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, like the drain passage 104 of the prior art shown in FIG. Has been done. Between both drain passages 71,
A support seat 72 is formed immediately above the camshaft 3, and a guide plate 73 is fixed to the support seat 72 with bolts (not shown). The guide plate 73 is curved along the upper half circumference of the camshaft 3 with a slight interval, and its front-rear width (direction orthogonal to the paper surface in FIG. 4) extends over the entire front-rear dimension of the drain passage 71. The guide plate 73 covers the upper half of the camshaft 3, and the lower openings of both drain passages 71 are located on both sides of the camshaft 3 as in the first embodiment.

Since the cam phase varying device of the present 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 is drain passage 71 as shown by the arrow. Guide plate 7 while flowing inside
Guided by 3, the camshaft 3 is discharged directly from both sides of the camshaft 3 onto the cylinder head 1 without landing on the rotating camshaft 3. Therefore, similarly to the first embodiment, the occurrence of oil mist due to agitation in the camshaft 3 is prevented, and the oil consumption increases, the exhaust gas deteriorates, and the phase controllability deteriorates due to air mixing in the oil. Various problems can be avoided in advance.

Although the description of the embodiment has been completed, the embodiment of the present invention is not limited to this embodiment. For example,
In the first and second embodiments, the cam phase varying device of the type 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 hydraulic pressure is arranged directly above the camshaft 3. Therefore, for example, it may be embodied in a cam phase varying device of a type in which the helical gear is hydraulically operated along the axial center of the camshaft 3 to adjust the phase.

Further, in the first embodiment described above, the drain passages 62 are inclinedly arranged in a substantially V shape, and in the second embodiment, the guide plate 73 is provided, so that the lower opening portions of the drain passages 62, 71 are provided. The camshafts on both sides of the camshaft 3,
The point is that oil from the drain ports 60 and 61 can be prevented from falling onto the camshaft 3, and the shape and configuration of the drain passage may be variously changed.

[0026]

As described above, according to the cam phase varying device of the present invention, the hydraulic fluid discharged from the hydraulic fluid switching means is guided by the drain passage and positioned to the side of the camshaft.
It is designed to prevent discharge from the lower opening of the drain passage where it is installed and to reach the rotating camshaft, which prevents oil mist from being generated by stirring on the camshaft and increases oil consumption. Various problems such as deterioration of exhaust gas and deterioration of phase controllability due to air mixing in oil can be avoided.

[Brief description of drawings]

1 shows the cam phase varying device of the first embodiment, I in FIG.
It is a -I line sectional view.

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

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

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

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

[Explanation of symbols]

3 camshaft 4 Timing pulley (power transmission member) 6 Actuator part (Phase variable means) 17a Advance hydraulic chamber (hydraulic actuator) 17b Delayed hydraulic chamber (hydraulic actuator) 45 OCV (hydraulic oil switching means) 62,71 drain passage

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) F01L 1/34

Claims (2)

(57) [Claims] 1. 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 a relative rotation angle between the power transmission member and the camshaft. Phase changing means having a hydraulic actuator that is provided so that it is possible, a hydraulic oil supply source that supplies hydraulic oil to the hydraulic actuator of the same phase changing means, and the phase changing means and the operation that are arranged directly above the camshaft. A hydraulic oil switching device that is connected between an oil supply source and controls the hydraulic pressure of the hydraulic actuator, and a lower opening is located laterally of the camshaft,
Switching the hydraulic oil from the hydraulic actuator to the hydraulic oil
A cam phase varying device, comprising: a drain passage for discharging from a means . 2. The upper half of the circumference of the camshaft is covered.
A guide plate is installed on the bottom of the drain passage.
Side opening is located on the side of the camshaft.
The cam phase varying device according to claim 1, characterized in that