JPS59158305A - Engine valve timing controller - Google Patents

Abstract

PURPOSE:To control valve timing with high response and reliability by varying the contacting position between a cam face for specific angular position of cam shaft and pressure receiving section of tappet contacting against valve stem in accordance with running condition. CONSTITUTION:Suction side and exhaust side valve moving mechanisms for opening/closing los load/heavy load suction valve and exhaust valve respectively are provided. Cam face 9b of cam shaft 9 will contact against pressure receiving section 13a while tappet 13 has pressing section 13b for transmitting force from can face 96 to the valve stem 5s. The tappet 13 is inserted slidably into an insertion hole 14a. An operating system 15 for rolling a member 14 rotatable around the cam shaft 9 in accordance with engine operating state is provided. Consequently engine valve timing can be controlled with high response and reliability.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a valve timing control device for an engine, and in particular to a variable valve timing control device for variably controlling valve timing according to engine operating conditions in a valve train that controls the opening and closing of intake and exhaust valves. It is about the mechanism.

In general, it is preferable for the valve timing of the intake and exhaust valves in an engine to be variably controlled in accordance with the operating state of the engine.

For example, when the engine is operated with a low angle load, it is preferable to shorten the overlap period of the intake and exhaust valves because this reduces the amount of residual exhaust gas and improves combustion stability. Further, when the engine is operated at high load and low speed, by shortening the overlap period of the intake and exhaust valves, blowback of intake air can be prevented and filling efficiency can be improved.

On the other hand, when the engine is operated at high load and high speed, it is preferable to set the opening period of the intake valve to be long because this increases the filling efficiency and improves the engine output.

For this reason, various variable mechanisms for variably controlling valve timing in the valve train of an engine have been proposed. For example, as disclosed in Japanese Patent Publication No. 52-35819, a planetary gear having a centrifugal cover is interposed between the output shaft of the engine and the camshaft to change the relative position of the output shaft of the engine and the camshaft. There are some models in which the camshaft is a three-dimensional camshaft and the three-dimensional camshaft is slid.

However, all of the above-mentioned conventional methods have complicated and large-scale structures, have poor variable control response and reliability, and tend to generate loud noise, making them impractical. there were.

The present invention has been made in view of the above, and effectively utilizes the existing valve train Ia4% to adjust the contact position between the cam surface and the pressure receiving part of the tappet that contacts the valve stem with respect to a specific angular position of the camshaft. The structure is simple, responsive, and
The object of the present invention is to provide a valve timing control device equipped with a highly practical variable mechanism that can perform variable control with high reliability and generates little noise.

In order to achieve this object, the configuration of the engine valve timing control device of the present invention is such that the valve timing control device of the present invention has a tappet having a pressure receiving part that receives force from the cam surface of the camshaft and a pressing part that transmits the force from the cam surface to the valve stem. - and a rotary member having a fitting hole into which the tappet is slidably inserted, and rotatably supported around the force shaft 1-, and the rotary member is placed in the operating state of the engine. An engine valve timing control device comprising an operating device that swings around a camshaft in accordance with the rotational direction of the camshaft, the external shape of the tappet pressing portion being aligned with the rotational axis of the camshaft along the swinging direction of the rotating member. It is characterized by being formed in an arc shape with the center at .

As a result, in the present invention, by rotating the rotating member around the camshaft using the operating device, the contact position between the cam surface and the pressure receiving part of the tappet can be adjusted to a specific angle position of the camshaft depending on the operating state of the engine. The valve timing can be variably controlled by changing the position around the camshaft. Even when the above rotating member is rotated to move the tappet around the camshaft, if the distance from the rotation axis of the camshaft to the valve stem at a specific angular position of the camshaft is not constant, the valve stem will be cleared. However, by making the outer surface shape of the tappet pressing part that comes into contact with the pulse system into an arc shape centered on the rotational axis of the camshaft along the swinging direction of the rotating member, the above-mentioned valve clearance can be kept constant. This is to prevent the occurrence of noise and deterioration of valve drive performance due to changes in the valve clearance.

Embodiments of the present invention will be described in detail below with reference to the drawings.

Figures 1 and 2 show a four-cylinder engine of the f-yual induction system, in which each cylinder is provided with a pair of intake ports and a pair of exhaust ports for low-load and high-load applications. An example to which the invention is applied will be shown. Engine body 1
The first to fourth cylinders 2 are arranged in series along the center line 9.
a to 2d' are formed, and each cylinder 2a to 2d has a pair of intake ports 3a for low load and high load, respectively.
3b, and a pair of first and second exhaust ports 4a.

4b are provided so as to open in parallel in a direction substantially parallel to the direction of the cylinder row. Each high-load intake port 3b of the first cylinder 2a and the second cylinder 2b.

3b and each second exhaust port 4b, 4. Similarly, the high-load intake ports 3b of the third cylinder 2G and the fourth cylinder 2d, the two 3b's, and the second exhaust ports 4b of the third cylinder 2G and the fourth cylinder 2d are arranged adjacent to each other back to back.
, 4b are also arranged adjacent to each other.

The low-load and high-load intake ports 3a and 3b of each cylinder 2a to 2d have intake ports h3a at the frontage to the cylinders.
, 3b are opened and closed at predetermined timings, respectively.Low load and high load intake valves 5a.

On the other hand, at the openings to the cylinders of the first and second exhaust boats 4a and 4b of each cylinder 2a to 2d, a first exhaust port is provided which opens and closes each exhaust port 4a and 4b at a predetermined timing, respectively. and second exhaust valves 6a and 6b are provided. Furthermore, an on-off valve 7 that is opened during high-load operation of the engine is disposed in the high-load intake passage 7b of the intake manifold connected to the high-load intake port 3b of each cylinder 2a to 2d. During low-load operation, the low-load intake port 3 communicates with the low-load intake passage 78.
Intake air is supplied to each of the cylinders 2a to 2d only from a, while during high-load operation of the engine, intake air is supplied from both the low-load and ^load intake ports 3a+3b. On the other hand, the first and second exhaust boats 4a and 4b of each cylinder 2a to 2d are connected to the first and second exhaust passages 7, respectively.
c and 7d.

The engine main body 11 includes an intake side valve operating mechanism 8a that controls opening and closing of the low-load and square cylinder intake valves 5a and 5b in each cylinder 2a to 2d, and first and second exhaust valves 6a.
+6b is provided with an exhaust side valve train 4f48b that controls the opening and closing of the valve.

The intake side valve mechanism 88 is disposed on the intake side of the engine body 1 in parallel with the center wA9 of the engine body, and is connected to the timing belt 1.
10 through the engine crankshaft (not shown)
It has an intake side camshaft 9 which is rotationally driven by
The intake side camshaft 9 has a cam surface 9 corresponding to the low-load and high-load intake valves 5a and 5b of each cylinder 2a to 2d.
a and 9b are formed in the same shape, and rotation of this intake side camshaft 9 opens and closes the low load intake valve 5a and the high load intake valve 5b. On the other hand, the exhaust side valve mechanism 8b is disposed on the exhaust side of the engine body 1 in parallel with the intersection of the center lines of the engine body.
0, and the exhaust side camshaft 10 has cam surfaces 10a, 1 corresponding to the first and second exhaust valves 5a, 5b of each cylinder 2a to 2d.
0b are formed in the same shape, and rotation of this exhaust side camshaft 10 opens and closes the first exhaust valve 6a and the second exhaust valve 6b.

The above-mentioned intake side valve operating mechanism 88 includes intake valves 5b, 5b for mutually adjacent load on both sides of the first cylinder 2a and the second cylinder 2b,
and two first variable mechanisms 1 according to the present invention that variably control the valve timings of the mutually adjacent double load intake valves 5b, 5b of the third cylinder 2C and the fourth cylinder 2d.
1.11, and the exhaust side valve mechanism 8b also includes second exhaust valves 6b, 6b of the first and second cylinders 2a, 2b adjacent to each other, and second exhaust valves 6b, 6b of the third and fourth cylinders 2c, 2d second
Two second variable mechanisms 12.12 according to the present invention that variably control the valve timing of the exhaust valves 6b, 6b, respectively.
is provided.

These first and second variable mechanisms 11, 12 have the same configuration as shown in an enlarged view in FIG. That is,
The first variable mechanism 11 has a pressure receiving part 13a which receives a force from the cam surface 9b at one end (upper end) of which is in contact with the cam surfaces 9b and 9b of the intake side camshaft 9, and a pressure receiving part 13a which receives a force from the cam surface 9b, and the opposite side C of the high load intake Valve 5b.

Pressing surface 13g that comes into contact with valve stem 5s, 5s of 5b
, a tappet 13.13 having a suppressing part 13b that transmits the force from the cam surface 9b to the pal system 5S and a cylindrical sliding part 13C, and the tappet 13.13 being able to freely slide in the vertical direction. Two insertion holes 14a, 1 to be inserted and held
4a and an F surface 14b formed in an arc shape corresponding to the arc shape surface 1a of the engine main body 1,
A rotating member 14 is rotatably supported on the intake camshaft 9 so as to allow mutual rotation, and is capable of rotating around the intake camshaft 9. and an operating device 15 that swings the intake side camshaft 9 around the rotation axis according to the rotational axis of the intake side camshaft 9.
The variable mechanism 12 has a component of the first variable mechanism 11 "'J".
6S is the valve stem of the second exhaust valve 6b).

The rotating member 14 is supported by the intake side camshaft 9 at a central portion between the fitting holes 11a and 14a, and is divided into upper and lower parts at this supported portion.
6 are connected together.

The operating device 15 is arranged parallel to the center line p of the engine body, and is connected to each rotating member 14.14 of the two first variable mechanisms 11.11.
A rocking shaft 17 connecting the upper end portions, and a rocking shaft 17 disposed at right angles to the rocking shaft 17 and engaged with the medium heating portion of the rocking shaft 17, and formed so as to be able to reciprocate in the left-right direction in FIG. The reciprocating shaft 18 is reciprocated in the above direction by converting, for example, the rotational motion of a motor into reciprocating motion, and the reciprocating shaft 18 is reciprocated in the above direction.
The driving device 19 rotates the rotating member 14 as described above via the rotating member 7 . This drive device 19 receives a rotation speed signal 81 output from a rotation speed sensor 20 that detects the engine rotation speed, and a load sensor 2 that detects the engine load.
When the load signal S2 outputted by the engine 1 is input, the drive unit 1 is driven so as to avoid the reciprocating motion @ 18 in the right direction in FIG. be done. Due to this movement of the reciprocating shaft 18, the swing shaft 17 rotates in the same direction as the rotational direction X of the intake side camshaft 9 (clockwise in FIG. It is rotated in the above-mentioned X direction around .

The high-load intake valve 5b is slidably supported by a valve guide 32 and has a valve spring 3, similar to a normal intake and exhaust valve.
1 is biased upward, that is, in the valve closing direction,
When the intake camshaft 9 rotates in the X direction and its cam surface 9b presses the pressure receiving part 13a of the tappet 13, and the tappet 13 is pushed down in the insertion hole 14a, the biasing force of the valve spring 31 It is pushed down by the pressing part 13b of the tappet 13, and the high-load intake boat 3b is opened (of course, the low-load intake valve 5a is also opened in the same way). On the other hand, the rotating members 14, 14 are
When the tappet 13.13 is rotated in the direction, the tappet 13.13 also rotates in the direction
4.1/I, and the contact position of the cam surfaces 9b, 9b and the tappet pressure receiving parts 13a, 13a relative to a specific angular position of the intake camshaft 9 is delayed with respect to the rotational direction X of the intake camshaft 9. The valve timing of each high-load intake valve 5b, 5b is shifted to the delayed side.

The above operation is similarly performed on the second exhaust valve 6b by the second variable mechanism 12.

Furthermore, as a feature of the present invention, as shown in enlarged detail in FIG.
(13'b), that is, the valve stem 5s (6
The suppression surface 13g (13'g) that s) comes into contact with is when the tappet 13 (13') is in a position where it comes into contact with the reference inner portion 9'b (10'b) of the cam surface 9b (10b). , is formed into a spherical surface centered at the point where the axis of rotation of the camshaft 9 (10) intersects with the axis of the pulse system 53 (63), and the rotating member 14<14. The rotating member 14 (14') is always arranged in an arc shape centered on the rotation axis of the cam shirt l-9 (10) with respect to the swinging direction of the rotating member 14 (14'). Even if the camshaft 9 (10) rotates in the X direction, the t
The distance 1111fr from the rotation axis of the camshaft (10) to the valve stem 5s (6s) is kept constant.

An oil passage 9C similar to that provided in a normal camshaft is formed in the center of the intake side force shaft 1-0, and communicates with an oil pump (not shown). An oil passage 9d that extends in the radial direction and opens at the cam surface 9b is communicated with the A oil passage 9C. is guided and lubricates.

In addition, the rotating member support portion 9e of the camshaft 9 and the camshaft bearing portion 30 are connected to each other by another oil passage (not shown).
Lubricating oil is introduced into the parts to provide lubrication.

The pressure receiving part 13a of the tappet 13 has an oil passage 13e communicating with the internal cavity 13d of the tappet 13, and the pressing part 13b of the tappet 13 has oil passages 13f, 13f communicating with the internal cavity 13d. are formed respectively, and after the lubricating oil that lubricates between the cam surface 9b and the tappet 13a to the pressure receiving part 13a flows into the internal cavity 13d of the tappet 13 from the oil passage 13e, the oil passes through the oil passages 13f, 13f. From the tappet pressing part 13b (
(pressing surface) to lubricate the space between the suppressing portion 13b and the valve stem 5S of the high-load intake valve 5b. The lubricating oil supply system to the tappet 13' on the exhaust side is constructed in the same way as on the intake side, and the exhaust side camshaft 10 has oil passages 10c and 10d corresponding to each oil passage of the intake side camshaft 9. Further, the exhaust side tappet 13' is provided with oil passages 13'e and 13'[ corresponding to each oil passage of the intake side tappet 13. In addition, 14c (14'C) is the rotating member 1
This is an oil passage for supplying lubricating oil between the fitting hole 14a (14/a) of No. 4 (14') and the tappet sliding portion 13c (13'c).

Next, the operation of the apparatus of the above embodiment will be explained.

During low-load operation of the engine, the first and second variable mechanisms 11.12 are inactive, and the low-load and high-load intake valves 5a in each cylinder 2a to 2d.

5b and 1st. The second exhaust valves 6a, 5b are controlled to open and close at predetermined valve timings by intake side and exhaust side valve operating mechanisms 13a, 8b, respectively.

That is, as shown by solid lines in FIG. 5, the valve timings of the first J'3 and the second exhaust valves 5a and 5b are controlled so that they open near the bottom dead center of the piston and then close near the top dead center. In addition, low load and high load intake valves 5a, 5
The valve timing of both valves b is controlled to shorten the overlap period with the exhaust valves 5a and 5b so that they open near the top dead center of the piston and then close near the bottom dead center of the piston. Further, the high-load intake passages 7b in each cylinder 2a to 2d are closed by the opening operation of the on-off valve 7, and air is taken in only from the low-load intake port 3a.

On the other hand, when the engine is operating at high load and low speed, the on-off valve 7 of the high load intake passage 7b is opened, and the low load intake port 3 is opened.
In addition to the high-load intake boat 3b, air is also taken in from the high-load intake boat 3b, but both the first and second variable mechanisms 11.12 are set to a non-operating state, and the intake and exhaust valves 5a, 5b and 6a, 6
By shortening the overlap period (b) and preventing the intake air from blowing back, the filling efficiency is increased. Moreover, in this case, each cylinder 2
In the exhaust strokes a to 2d, the first and second exhaust ports 4a, 4. b are opened and closed by exhaust valves 6a and 5b, respectively, so the effective opening area for exhaust is increased compared to a single exhaust boat engine, improving scavenging efficiency and further improving the above-mentioned charging efficiency. can.

When the engine is operating at high load and high speed, the first and second variable mechanisms 11.12 operate together, and as shown by the imaginary lines in FIG.
(Among the pair of intake valves 5a and 5b, the valve timing of the second exhaust valve 6b is delayed by the second variable IN mechanism 12, and the valve timing of the high-load intake valve 5b of the pair of intake valves 5a and 5b is delayed by the first variable IN mechanism. 11, J: T: Controlled to shift to the lag side.

Further, the high-load intake passages 7b of each cylinder 2a to 2d are separated by the opening operation of the on-off valve 7, and air is also taken in from the high-load intake port 3b as in the above-described high-load, low-speed operation.

In this way, by lengthening the total opening period of both intake valves 5a and 5b as a whole, and by extending the opening period to the delayed side where the inertial effect of the intake air is large, the filling efficiency of the intake air is significantly improved. Dramatically improves thrust performance under high load and high rotation speeds. Also, both exhaust valves (3a.

By lengthening the total valve opening period of 6b as a whole,
Scavenging efficiency is significantly improved, and the above-mentioned charging efficiency is greatly improved.

Each of the variable mechanisms 11 and 12 described above has a tappet 13 (1
3') and an operating device 15 (15') for rotating the rotating member 14 (14') around the camshaft 9 (10). Therefore, the structure is simple, and manufacturing is easy and inexpensive.

Moreover, the variable control of the variable mechanism 11.12 allows the cam surface 9b (
10b) and the tappet pressure receiving portion 13a (13'a) by changing the contact position around the camshaft 9 (10), variable control can be performed stably with good responsiveness and reliability.

The tappet 13 (13') is the rotary member 14 (
The camshaft 9 of the rotating member 14 (14') is fitted and held in the fitting hole 14a (14' a ) of the rotating member 14 (14').
(10) The camshaft 9 moves when the rotating member 14 (14') rotates.
Camshaft 9 (10) at a specific angular position of (10)
) from the rotation axis to the valve stem 5s (6s>)
! When ltr changes, the valve clearance (cam surface 9b (10b) of camshaft 9 (10) and tappet receiver LE
The gap between the portion 13a (13'a>) changes, and in such a case, noise, deterioration of valve drive performance, etc. occur.

However, as mentioned above, the valve stem 5s (6S)
The pressing surface 13g (13'q) of the tappet pressing part 13b (13'b) that comes into contact with the rotating member 14 (14'
) is formed in an arc shape centered on the rotation axis of the camshaft ~9 (10), so that the rotating member 1
When the camshaft 9 (14') rotates, the camshaft 9 (10) at a specific angular position
10) The distance 1lIlr from the rotation axis to the pulp stem 5s (6s) remains constant, and the valve clearance is kept constant to a minimum. Therefore, when one valve is installed, the generation of noise caused by changes in valve clearance is suppressed, and valve drive performance is also maintained satisfactorily.

In the above embodiment, the present invention is applied to a dual induction type 4-valve engine having a low-angle front intake boat and a high-load intake boat, but the present invention can of course be applied to other engines as well. It is. For example, as shown in FIG.
It can also be applied to regular 4-cylinder engines with
In this case, the first cylinder 102a and the second cylinder f are adjacent to each other.
d102b, and the third cylinder 102c and the fourth cylinder 102
Intake ports h103, 103 (or exhaust boats 104, 104) are arranged adjacent to each other at d, and the intake valves (or exhaust valves) are arranged adjacent to each other at the camshaft center S of the valve train system.
A variable mechanism 111 (112) similar to the variable mechanism 11, 12 in the previous example (E) may be provided across the gap. When the valve timing of the intake valve is made variable in this way, the valve timing is set as shown in FIG.

That is, when the engine is operated at high load and high speed, the valve timing of the intake valve is shifted to the delayed side as shown by the imaginary line in FIG. In this way, by setting the valve opening period on the delayed side where the inertial action of the intake air is large, the filling efficiency of the intake air is improved, and the output performance oh is improved.

In addition, in the embodiment shown in FIG. 1, the intake and exhaust valves 5'
Although the specific operation of the engine in which the valve timing in 1) and 6b is variably controlled is when the engine is under high load and at high rotation speed, the valve timing may also be variably controlled during other operations as required.

Furthermore, in the embodiment shown in FIG.
A pair of intake boats 3a at ~2d.

3b and a pair of intake valves 5a, 5b, a pair of exhaust boats 4a, 4b and a pair of exhaust valves 6a, 6b,
High-load intake valves 5a, which are arranged parallel to the center line evening direction, divided into the intake side and exhaust side of the engine body 1, respectively;
5b and the second exhaust valves 6b and 6b are arranged adjacent to each other, it goes without saying that other arrangement configurations may be used. However, the arrangement as in the embodiment of FIG.
Intake valves 5b for elevated cylinders between 5b and second exhaust valve 6
This is advantageous because each of b and 6b can be controlled by one variable mechanism 11, 12.

Furthermore, in the embodiment shown in FIG. 1, the rotating member 14 (
14') is directly supported on the camshaft 9 (10) so as to allow mutual rotation, and rotates around the camshaft 9 (10).
is formed into an arcuate surface centered on the axis of the cam shirt h9 (10), and correspondingly, the lower surface 14b (14'b) of the rotating member 14 (14') is formed into an arcuate shape, so that the rotation The lower surface 14b (14'b) of the movable member 14 (14') may be guided in sliding contact with the arcuate surface 1a to rotate around the cam shirts 1 to 9 (10).

Further, in the embodiment shown in FIG. 1, the tappet pressing portion 13b
Pressing surface 13(] (13' b ) of (13'
CI) is formed into a spherical surface centered on the rotation axis of the camshaft 9 (10), and the tappet 13 (13') is formed into a fitting hole 14. of the rotating member 14 (14'). If the rotational axis of the camshaft 9 (10) is slidably inserted and held while being prevented from rotating relative to the rotation member 14 (14'a), the rotation axis of the camshaft 9 (10) can be simply moved along the swinging direction of the rotation member 14 (14'). It may also be formed into a circular arc surface with the center as the center.

As explained in detail above, the engine valve timing control device of the present invention is capable of reliably and responsively controlling engine valve timing with simple lateral movement, and is capable of variable control of valve timing. This will greatly contribute to the ease of implementation. Furthermore, since the valve clearance is kept constant even when the rotating member swings, valve drive noise can be kept low and valve drive performance can be maintained well.

[Brief explanation of drawings]

Fig. 1 shows an embodiment in which the present invention is applied to a dual-induction four-cylinder engine. 1 is an enlarged perspective view of the variable mechanism portion of the embodiment shown in FIG. 1, FIG. 4 is an enlarged vertical sectional view of the variable mechanism portion when the rotating member is swung, and FIG. 5 is an enlarged perspective view of the variable mechanism portion of the embodiment shown in FIG. An explanatory diagram showing the valve timing of the valve, FIG. 6 is a schematic diagram showing an embodiment in which the present invention is applied to a normal four-cylinder engine, and FIG. 7 shows the valve timing of the intake and exhaust valves in the embodiment of FIG. 6. FIG. 5a, -5b...Intake valve, 5s...Valve stem,
6a, 51)...Exhaust valve, 9,1o...Camshaft, 9a, 9b, 10a, 10b, , cam surface, 11'
-...first variable mechanism, 12...second variable mechanism, 13.
13'... Tappet, 13a, 13'a... Tappet pressure receiving part, 13b, 13'b... Tappet pressing part,
13g, 13'Q... Pressing surface, 14.14'... Rotating member, 14a, 14'a... Fitting hole, 15.15'
...Operating device. Procedural amendment written spontaneously) 1. Indication of the case 1981 Patent Application No. 31300 2 Name of the invention Engine valve timing control device 3 Person making the amendment Relationship to the case Patent applicant Address 3-1 Shinchi, Fuchu-cho, Aki-gun, Hiroshima Prefecture Name <313) Toyo Kogyo Co., Ltd. Representative Yamayama @ Yoshiki 4, Agent Kotsu 550den 06 (445) 2128 Address Taihei Building, 1-4-8 Utsubohonmachi, Nishi-ku, Osaka Name Patent Attorney <7793) 1) Hiro 7
, Details of the amendment (1) In FIG. 2 of the drawings, the symbols r9' b J and r10' bJ are added as indicated in red ink on the attached corrected drawing (copy). (2) In FIG. 4 of the drawings, the reference numeral r9'bj is added and corrected as indicated in red ink on the attached correction drawing (copy). 8. List of accompanying books

Claims (1)

[Claims] (1) A tappet having a pressure receiving part that receives force from the cam surface of the camshaft and a pressing part that transmits the force from the cam surface to the valve stem, and a fitting hole into which the tappet is slidably inserted. , a valve timing control for an engine, comprising a rotating member rotatably supported around the camshaft, and an operating device that swings the rotating member around the camshaft depending on the operating state of the engine. A valve timing device for an engine, characterized in that the outer surface shape of the tappet suppressing portion is formed in an arc shape centered on the rotation axis of the camshaft along the swinging direction of the rotating member. Control device.