JP3385870B2 - Valve characteristic control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION [0001] 1. Field of the Invention [0002] The present invention relates to a valve characteristic control device for an internal combustion engine that controls the opening and closing characteristics of an intake valve and an exhaust valve based on hydraulic control. Relates to an oil passage structure suitable for use in a device integrally provided in a cylinder head of the engine. 2. Description of the Related Art Conventionally, in an internal combustion engine such as a vehicle-mounted engine, the opening and closing characteristics of an intake valve and an exhaust valve have been appropriately changed in order to improve output and reduce emission. Will be For example, in a valve timing control device disclosed in Japanese Patent Application Laid-Open No. 6-330712, the output and the emission of an internal combustion engine are reduced by changing the opening and closing timing of the valves. In general, such a valve timing control apparatus includes a valve timing adjusting mechanism, a hydraulic pressure source, and a hydraulic pressure source arranged between the valve timing adjusting mechanism and the hydraulic pressure source to control a hydraulic pressure supplied from the hydraulic pressure source. Control valve. [0004] Of these, the valve timing adjustment mechanism is:
It is attached to a camshaft provided on a cylinder head for driving valves such as the intake valve and the exhaust valve. The valve timing adjusting mechanism includes, for example, a pulley connected to a crankshaft of an engine via a timing belt, and a ring gear for connecting the pulley to the camshaft so as to be integrally rotatable. The ring gear is connected to the pulley and the camshaft via a helical spline provided on the ring gear. In the valve timing adjustment mechanism, the relative rotational phase between the pulley and the camshaft, that is, the valve timing, is changed as the ring gear moves in the camshaft axial direction. Hydraulic chambers are provided on both sides in the moving direction of the ring gear, and the moving direction and the moving amount of the ring gear are determined based on the hydraulic balance in the hydraulic chambers. On the other hand, the control valve includes a spool slidably provided in the housing, a coil spring for urging the spool in one direction, and attaching the spool in a direction opposite to the above direction based on energization from the outside. And an energizing electromagnetic solenoid. And, in this control valve, in accordance with the amount of movement of the spool set based on the balance between the amount of electricity to the electromagnetic solenoid and the biasing force of the coil spring,
The hydraulic pressure from the hydraulic pressure source is selectively supplied to the hydraulic chamber of the valve timing adjustment mechanism. As described above, the ring gear is moved in the axial direction of the camshaft by the selective supply of the hydraulic pressure to these hydraulic chambers, so that the relative rotation phase between the pulley and the camshaft, that is, the valve timing is changed. is there. In the valve timing control device configured as described above, the control valve may be incorporated in a cylinder head of the engine to make the entire engine compact. In this case, as shown in FIG. 5, an accommodation hole 73 is provided in the cylinder head 72, and the accommodation hole 73 is provided.
The control valve 71 which is a control valve for controlling the hydraulic pressure
Is inserted. The control valve 71 includes an electromagnetic solenoid 71a for adjusting the movement of the spool (not shown),
First and second supply / discharge ports 74 and 75, and supply port 7
6 and first and second discharge ports 77 and 78. That is, in the control valve 71, when the electromagnetic solenoid 71a is demagnetized, the spool is moved in one direction by the urging force of a coil spring (not shown). As a result, the first supply / discharge port 74 is provided. And supply port 7
6 and the second supply / discharge port 75 and the second discharge port 78. Also, when the electromagnetic solenoid 71a is excited, the spool is moved in the opposite direction to that described above against the urging force of the coil spring, and as a result, the first supply / discharge port 74 and the first discharge port 77 communicate with each other. In addition, the second supply / discharge port 75 and the supply port 76 communicate with each other.
The specific structure of the control valve 71 that functions as described above is also described in the above publication and is well known. On the other hand, the control valve 7 is
An advance control oil passage 79, a retard control oil passage 80, a supply oil passage 81, and a discharge oil passage 82 are provided corresponding to the above-mentioned respective port positions. Incidentally, the advance control oil passage 79 is connected to the first supply / discharge port 74, and the retard control oil passage 80 is connected to the second supply / discharge port 75. The supply oil passage 81 is connected to the supply port 76, and the discharge oil passage 82 is connected to the first and second discharge ports 77 and 78. The advance control oil passage 79 and the retard control oil passage 80 are oil passages connected to the above-described hydraulic chambers of a valve timing adjustment mechanism (not shown). This is an oil passage connected to the inside of the oil pan of the engine via an oil pump that is not used. The discharge passage 82 is also connected to the inside of the oil pan. The supply passage 81 is generally constituted by a hole 81a extending in the horizontal direction and a hole 81b extending in the vertical direction as shown in FIG. Therefore, in order to form the supply passage 81 in the cylinder head 72, for example, the hole 8 extending in the horizontal direction is formed in the cylinder head 72.
After first cutting 1a, a hole 81b extending in the vertical direction is cut from the upper surface 72a of the cylinder head 72 so as to be connected to the hole 81a. At this time, the hole 81b extending in the vertical direction passes through the housing hole 73 and is connected to the hole 81a.
6 is cut so as to correspond to position 6. And
Finally, the plug 85 is fitted into the upper end opening of the hole 81b opened on the upper surface 72a of the cylinder head 72, thereby completing the operation of forming the supply passage 81. The advance control oil passage 79 and the retard control oil passage 80
The discharge passage 82 is formed in the same procedure as the supply passage 81. That is, the oil passages 79, 80, and 82 are also provided with holes 79 a, 80 a, and 82 a extending in the horizontal direction, respectively, and from the upper surface 72 a or the lower surface 72 b of the cylinder head 72.
Holes 79b extending to connect to 4, 75, 77, 78,
80b and 82b. [0011] Thus, the control valve 7
By incorporating 1 into the cylinder head 72, the overall engine is certainly made compact. However, in the valve timing control device having such a structure, as described above, (a) the oil passages 79 to
The holes 79a to 82a and 79b to 82b forming the hole 82 need to be separately cut. (B) For example, a hole 7 cut in the vertical direction
For 9b to 82b, it is necessary to separately provide a plug 85 from the upper surface 72a or the lower surface 72b of the cylinder head 72 to close one of the oil passages. For example, processing of the cylinder head 72 is extremely complicated. When oil is supplied from the supply passage 81 to the hydraulic chamber of the valve timing adjusting mechanism through the advance or retard control oil passages 79 and 80, a part of the oil is supplied to, for example, the hole 81b. The fluid also flows into portions other than the portion connecting the supply passage 81a and the control valve 71. In addition, the control valve 71 is deteriorated, for example, because the oil accumulated in this portion is deteriorated and easily solidified.
May cause malfunction. Further, even if the oil in this portion does not solidify due to deterioration or the like, when the oil is supplied to the hydraulic chamber of the valve timing adjusting mechanism, the valve timing adjusting mechanism is operated until the oil is filled in the portion. Not enough hydraulic pressure to work. Therefore, the operation responsiveness of the valve timing adjusting mechanism is also deteriorated. The holes 81b and the like are provided in the cylinder head 72.
May be cut from the lower surface 72b, but in such a case, the situation remains the same.
In addition, as a valve characteristic control device, there is another device that adjusts the lift amount of the valve. In the device in which the control valve is used for the adjustment and the control valve is incorporated in a cylinder head of an engine, such a situation is also considered. They are generally common. SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to make it easier to process the control valve in the cylinder head when the control valve is incorporated into the cylinder head, thereby increasing the productivity. An object of the present invention is to provide a valve characteristic control device for an internal combustion engine. [0017] In order to achieve the above object, according to the first aspect of the present invention, at least a part or all of an oil passage communicating from a hydraulic pressure source to a control valve is provided. It consisted of bolt holes for attaching other devices or members to the cylinder head. Therefore, a special machining hole as an oil passage is not required. Further, the bolt hole is provided with a hydraulic pressure from the hydraulic pressure source.
And the supply passage connected to the supply passage is connected to the supply passage.
At the position of the supply port so that it connects to the supply port of the valve
Correspondingly processed from the upper surface of the cylinder head
And from the hydraulic source having the same bolt hole to the control valve.
Except for the part that reaches, the bolt
It shall be closed by the bolt screwed into the hole. What slave <br/>, braking oil supplied from the control valve to the valve characteristic adjustment mechanism, it can not accumulate in the portion other than the portion extending from the hydraulic source to the control valve in the bolt hole, the control valve of oil pressure to the valve characteristic adjustment mechanism Supply will take place quickly. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 1, a crankshaft 12 is provided below the engine 11, and a pulley 12 a is attached to the crankshaft 12. A plurality of pistons (not shown) provided inside the engine 11 are connected to the crankshaft 12 via connecting rods. A cylinder head 13 is provided above the engine 11. FIG. 2 shows a plan structure of the cylinder head 13. The cylinder head 13 is provided with a pair of camshafts 14 in parallel. The camshaft 14 is rotatably supported by a plurality of bearings 15 provided on the cylinder head 13. FIG. 3 further shows a cross-sectional structure of the cylinder head 13 at the bearing 15 portion. The bearing 15 comprises a bearing 16 formed on the cylinder head 13 and a cam cap 17 provided above the bearing 16. The cam cap 17 is fixed to the cylinder head 13 by a pair of bolts 18.
Attached to. The camshaft 14 is sandwiched between the bearing 16 and the cam cap 17. Also, as shown in FIG.
Are provided with a plurality of cams 14a, and two cams 14a are provided for each piston, and are located corresponding to intake valves and exhaust valves (not shown) constituting a four-valve system. Here, as shown in FIG. 1 or FIG. 2, one end of one camshaft 14 is provided with a valve timing adjusting mechanism 1 having the same structure as the above-described conventional mechanism.
9 are provided. This valve timing adjustment mechanism 1
A pulley 19 a is attached to 9, and a pulley 20 is attached to an end of the other camshaft 14. As shown in FIG. 1, the pulleys 19a and 20 of both camshafts 14 are connected to the pulley 12a of the crankshaft 12 via a timing belt 21, and the rotation of the crankshaft 12 via the timing belt 21 The power is transmitted to the camshaft 14. Each cam 14 shown in FIG.
In response to the rotation of No. 4, the intake valve and the exhaust valve are respectively opened and closed. By the way, the valve timing adjusting mechanism 19
Is provided in the camshaft 14 from the vicinity of the bearing 15 closest to the valve timing adjustment mechanism 19 to the inside of the valve timing adjustment mechanism 19 for the advance control oil passage 22 and the oil for the retard control. A road 23 is provided. As shown in FIG. 3, a housing hole 24 extending in the horizontal direction is provided below the bearing 15 located closest to the valve timing adjusting mechanism 19 in the cylinder head 13.
Is provided. A control valve 25 for controlling the oil pressure supplied to the valve timing adjustment mechanism 19 is fitted in the accommodation hole 24. As shown in FIG. 3, the control valve 25 includes first and second supply / discharge ports 26 and 27 and a supply port 28.
And first and second discharge ports 29 and 30. The control valve 25 includes the conventional control valve 71 described above.
Similarly to (FIG. 5), a spool and a coil spring (not shown) are provided, in addition to the electromagnetic solenoid 25a. When the solenoid 25a is demagnetized, the spool is moved to one end of the control valve 25 by the biasing force of the coil spring. In this state, the first supply / discharge port 26 and the supply port 28 communicate with each other, and the second supply / discharge port 27 and the second discharge port 30 communicate with each other. When the electromagnetic solenoid 25a is energized, the spool is moved in the opposite direction to the above, against the urging force of the coil spring, and is positioned at the other end of the control valve 25. In this state, the first supply / discharge port 26 and the first
Discharge port 29 and the second supply / discharge port 2
7 and the supply port 28 communicate with each other. As shown in FIG. 3, the cylinder head 13 is provided with an advance control oil passage 31, a retard control oil passage 32, a supply oil passage 33, and a discharge oil passage 34. here,
The advance angle control oil passage 31 is connected to the first supply / discharge port 26 of the control valve 25.
, And the retard control oil passage 32 is connected to the second supply / discharge port 27 of the control valve 25. The supply oil passage 33 is connected to the supply port 28 of the control valve 25, and the discharge oil passage 34 is connected to the first and second discharge ports 29 and 30 of the control valve 25. The advance control oil passage 31 and the retard control oil passage 32 are oil passages connected to the advance control oil passage 22 and the retard control oil passage 23 of the camshaft 14, respectively. The supply oil passage 33 is an oil passage connected to the oil pan 36 of the engine 11 via the oil pump 35, and the discharge passage 34 is an oil passage directly connected to the oil pan 36.
The oil pump 35 and the oil pan 36 constitute a hydraulic pressure source. In this embodiment, the supply passage 33 is formed by a hole 33a and a bolt hole 38. The hole 33a is formed in the cylinder head 13 so as to extend in the horizontal direction. The bolt hole 38 is formed in the cylinder head 13 so as to pass from the upper surface 13a of the cylinder head 13 to the hole 33a through the housing hole 24 and to correspond to the supply port 28 of the control valve 25. I have. Then, the upper surface 13 of the cylinder head 13
A bolt 18 for attaching the cam cap 17 to the cylinder head 13 is screwed into an upper end opening 38a of a bolt hole 38 opening at a. The bolt 18 has a bolt hole 38 located above the accommodation hole 24,
That is, the hole 38 is formed to have a length capable of closing the portion other than the portion from the hydraulic pressure source to the control valve 25. In this embodiment, the advance control oil passage 31 and the retard control oil passage 32
The discharge passage 34 has the same configuration as that of the related art shown in FIG. 5, and includes holes 31a, 32a, 34a and holes 31b, 32b, 34b, respectively. According to such an oil passage structure, the control valve 2
The supply port 28 of No. 5 and the hole 33 a of the supply passage 33 are connected by a bolt hole 38 for attaching the cam cap 17 to the cylinder head 13. Therefore, the hole 33
a and a conventional hole for connecting the supply port 28 with
It is possible to save the labor of cutting separately from the bolt hole 38. The opening 38a of the bolt hole 38 opening on the upper surface 13a of the cylinder head 13 is
Bolt 18 for attaching 7 to cylinder head 13
Is closed by. Therefore, the opening 38 of the bolt hole 38
It is possible to omit a conventional stopper for closing a. Further, in the bolt hole 38, a portion other than a portion connecting the hole 33a and the control valve 25 is filled with the bolt 18, so that accumulation of oil in that portion is prevented. Further, since no oil flows into this portion, the oil is promptly supplied to the valve timing adjustment mechanism 19 via the advance or retard control oil passages 31, 32, and the operation of the valve timing adjustment mechanism 19 is started. Responsiveness is improved. As described in detail above, according to this embodiment,
The following effects (a) to (d) are obtained. (A) The bolt holes 38 for attaching the cam cap 17 to the cylinder head 13 make the holes 33 in the supply passage 33
a and the supply port 28 of the control valve 25.
Therefore, the conventional hole for connecting the hole 33a and the supply port 28 does not need to be separately cut from the bolt hole 38. Therefore, it is possible to save time and effort in processing the supply passage 33 in the cylinder head 13 and improve the productivity of the cylinder head 13. (B) The opening 38a of the bolt hole 38 is closed by the bolt 18 screwed into the bolt hole 38 when the cam cap 17 is mounted on the cylinder head 13. Therefore, a conventional plug for closing the opening 38a can be omitted, and the trouble of providing the plug can be omitted. (C) In the bolt hole 38, oil can be prevented from accumulating in a portion other than the portion connecting the hole 33a and the control valve 25, so that the oil accumulated in that portion is prevented from deteriorating and solidifying. be able to. Therefore, unlike the related art, it is possible to prevent the malfunction of the control valve 25 caused by the solidified oil. (D) Since oil does not flow into the bolt hole 38 except for a portion connecting the hole 33a and the control valve 25, when the oil is supplied to the valve timing adjusting mechanism 19, the valve timing adjusting mechanism 19 is operated. Sufficient oil pressure to operate works faster than before. Therefore,
The operation responsiveness of the valve timing adjusting mechanism 19 can be improved, and a delay in adjusting the opening / closing timing of the valve can be suppressed. The present invention can be embodied with the following modifications. (1) As shown in FIG. 4, for example, the first hole corresponding to the hole 40 formed by the core baseboard at the time of casting the cylinder head 13 so as to extend in the direction perpendicular to the paper surface of FIG.
The control valve 25 is arranged such that the discharge port 29 of the control valve 25 is located. The hole 40 is provided in the cylinder head 7 as shown in FIG.
2 is open on the side surface on the pulley 19a side. Therefore, here, the oil discharged from the first discharge port 29 by the hole 40 is returned to the oil pan 36 instead of the discharge passage 34 of the above embodiment. In this case, as in the above-described embodiment, the holes 34a
It is not necessary to cut the hole 34b for connecting the second discharge port 29 with the first discharge port 29, so that the labor can be saved. Further, since the hole 40 formed by the baseboard has a relatively large diameter, the oil discharged from the first discharge port 29 can be efficiently returned to the oil pan 36. (2) In the present embodiment, the supply passage 33 is constituted by the hole 33a and the bolt hole 38, but instead of this, the advance control oil passage 31, the retard control oil passage 32, or the discharge oil passage 3
4 may be constituted by holes 31a, 32a, 34a and bolt holes 38. In this case, the control valve 25 is arranged such that the first supply / discharge port 26, the second supply / discharge port 27, the first discharge port 29, or the second discharge port 30 is located corresponding to the bolt hole 38. . (3) In the present embodiment, the bolt 18 is connected to the hole 33 a of the supply passage 33 in the bolt hole 38 by the control valve 2.
The length is formed so as to be able to fill a part other than the part connecting the supply port 28 with the supply port 5, but the present invention is not limited to this. For example, the length of the bolt 18 may be shorter than in the embodiment. Even in this case, at least the effects shown in the above (a) or (b) can be obtained. (4) In this embodiment, the cam cap 17
Bolt holes 38 for attaching the
The supply passage 33, the advance control oil passage 31, the retard control oil passage 32, or the discharge oil 34 passage are formed by bolt holes for attaching members and devices other than the cam cap 17 to the cylinder head 13. Etc. may be configured. (5) In the present embodiment, the case where the oil passage structure according to the present invention is employed in the device for controlling the valve timing has been described. However, the present invention also relates to a device for controlling the valve lift amount and the like. The oil passage structure can be similarly applied. In addition, the valve whose valve characteristics are to be controlled, whether the valve timing or the valve lift, is arbitrary. That is, the valve to be controlled is
It may be an intake valve or an exhaust valve. Alternatively, both the intake valve and the exhaust valve may be used. (6) In this embodiment, the valve timing adjusting mechanism 19 may be of a vane type. According to the first aspect of the present invention, since a special machining hole as an oil passage is not required, the productivity of the cylinder head and, consequently, the valve characteristic control device is improved accordingly. [0046] Additionally, the plug is not required in order to bolt hole is closed by a bolt. Further, since the supply of the hydraulic pressure from the control valve to the valve characteristic adjusting mechanism is promptly performed, the operational response of the valve characteristic adjusting mechanism is improved. [0047]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing an outline of an engine equipped with a valve characteristic control device of the present embodiment. FIG. 2 is a plan view showing a cylinder head structure of the engine. FIG. 3 is a sectional view showing a structure in which a control valve is incorporated in the cylinder head. FIG. 4 is a cross-sectional view illustrating a structure in which a control valve is incorporated into a cylinder head in another example. FIG. 5 is a cross-sectional view showing a conventional structure for incorporating a control valve into a cylinder head. [Description of References] 13: Cylinder head, 13a: Upper surface, 13b: Lower surface,
14 ... camshaft, 17 ... cam cap, 18 ... bolt, 19 ... valve timing adjustment mechanism, 24 ... accommodation hole,
25 ... control valve, 31 ... advance control oil passage, 32 ... retard control oil passage, 33 ... supply passage, 34 ... discharge passage, 35 ... oil pump, 36 ... oil pan, 38 ... bolt hole, 40 ... hole.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F01L 1/34 F01L 1/04 F01M 1/06 F01M 1/16

Claims (1)

(57) [Claim 1] A valve characteristic adjusting mechanism for adjusting at least one of an intake valve and an exhaust valve of an internal combustion engine based on hydraulic pressure, a hydraulic pressure source, and a valve characteristic adjusting mechanism for the valve And a control valve disposed between hydraulic pressure sources to control a hydraulic pressure supplied to a valve characteristic adjusting mechanism, wherein the control valve is integrally formed with a cylinder head of the engine. , is constituted by a bolt hole for part or all of at least an oil path communicating with the control valve from the hydraulic source to attach other devices or members to the cylinder head, the
The bolt hole is provided with a supply passage through which hydraulic pressure is supplied from the hydraulic pressure source.
The supply passage is connected to a supply port of the control valve to be connected.
To the cylinder corresponding to the position of the supply port.
It is machined from the upper surface of the
Other than the portion from the hydraulic pressure source to the control valve,
Bolt screwed into the bolt hole from the upper surface of the solder head
A valve characteristic control device for an internal combustion engine that is closed by a valve.