JPS59153911A - Valve timing control device in engine - Google Patents

Abstract

PURPOSE:To prevent the twisting of rotating members, for slidably holding tappets, which are rotated around cam shafts to control the valve timing, by forming guide surfaces for the rotating members. CONSTITUTION:Tappets 13, 13' slide in fitting holes 14a, 14a' formed in rotating members 14, 14' which are rotatable about cam shafts 10a, 10b, and therefore, transmit the movement of cams to valves 5b, 6b. Due to the rotation of the rotating members 14, 14' by a drive device 19 in association with the running condition, the timing of opening and closing of the valves is controlled. Guide surfaces 1a, 1b having a sliding relationship with the rotating members, are formed corresponding to the side surfaces of the rotating members 14, 14' which are therefore prevented from twisting, thereby the reliability of the control may be ensured.

Description

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

In general, it is preferable from the viewpoint of engine operating performance that the valve timing of the intake and exhaust valves in the engine be variably controlled in accordance with the operating state of the engine.

For example, when the engine is running at low load, the A-
It is preferable to shorten the fluctuation period because it suppresses the amount of residual exhaust gas and improves combustion stability. Further, when the engine is operated under high load and at low speed, by shortening the overlap period of the intake and exhaust valves, blowback of intake air can be prevented and charging efficiency can be improved.

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

For this reason, various variable mechanisms for variable control of 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 those in which the camshaft is a vertical camshaft and the three-dimensional force 17 feet are slid.

However, all conventional systems have complicated and large-scale structures, have poor variable control response and reliability, and tend to generate loud noises, making them impractical. It was something.

The present invention has been made in view of the above, and effectively utilizes the existing valve mechanism to establish contact between the cam surface at a specific angular position of the camshaft and the pressure-receiving portion of the tappet that contacts the valve stem. By changing the position according to the operating condition of the engine, the variable control mechanism is simple in structure, responsive, reliable, and generates little noise, making it a highly practical variable mechanism. The purpose of this invention is to provide a valve timing control device having the following functions.

In order to achieve this object, the configuration of the valve timing control If of the engine of the present invention includes a tappet having a pressure receiving part that receives force from the cam surface on the cam shirt 1 and a pressing part that transmits the force from the cam surface to the valve stem. a rotary member having a fitting hole into which the tappet is slidably inserted and rotatable around the camshaft; This is a valve timing control device for an Ic engine, comprising an operating device for swinging the rotating member, and is characterized in that guide surfaces are formed along both sides of the rotating member in the swinging direction.

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 is variably controlled by changing the angle around the camshaft. The rotating member that slidably holds the above-mentioned tappet is connected to the tappet from the camshaft side.
- to receive the reaction force of the lateral force acting on the tappet in the direction perpendicular to the sliding direction of the tappet, and to transmit the force from the cam surface of the cam shirt 1 to the valve stem through the tappet 1- in the direction of the acting force line. On the other hand, when the sliding direction of tappet 1- is deviated, the rotating member is twisted by receiving the reaction force of the lateral force acting on tappet 1- from the valve stem side. Variable control of valve timing by rotation may not be performed reliably. Particularly in the case where the rotary member is supported in the center and holds two or more tappets on both sides of the rotary member that are connected to valves with different phases, the above-described phase shift may occur. The problem becomes noticeable. Therefore, by guiding the rotating member with a guide surface formed along the swinging direction, the ++X deviation of the rotating member is suppressed and the reliability of variable valve timing control is improved. There is a C of us.

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

Figure 1 and Figure 2 show a dual induction four-cylinder engine in which one cylinder has a pair of intake ports for low load and high load, and a pair of exhaust ports. An embodiment in which the present invention is applied is shown below.The Wanginjin wooden body 1 has first to fourth Qi Ws arranged in series along its center line 9.
52a to 2d are formed and d3, each cylinder 2a to 2(
1 each have a pair of intake boats 1 to 3a, 3b for low load and high load, and a first and second pair of 1j1 intake boats 4a.

/lb are installed so as to open in parallel with the direction of the cylinder row (in the j direction).

31) The high-load intake boats 3b and 4b of the third cylinder 2C and the fourth cylinder 2d are arranged so that they are adjacent to each other and back to back. 311 and the second exhaust ports 4b, 4b are also arranged so as to be in contact with each other.

Each intake boat t-3 is provided at the frontage to the cylinders of the low-load and high-angle Wi intake boats 3a and 3b of each cylinder 2a to 2d.
Intake valve 5a for low load and high 11 load river which opens and closes a and 3b at predetermined timing, respectively.

On the other hand, each exhaust boat 1-4a, 4b is connected to the first and second exhaust boats 4a, 4b of each cylinder 2a-2d at a predetermined timing. First and second exhaust valves 6a, 61) that open and close are provided. Further, the high-load intake passage 7b of the intake manifold connected to the high-load intake port 3b of each cylinder 2a-26 is provided with an on-off valve 7 that is closed during high-load operation of the engine. During low load operation of the engine, intake air is supplied to each cylinder 2a to 2d from only the low load intake ports 1 to 38 communicating with the low load intake passage 7a, while during high load operation of the engine, intake air is supplied to each cylinder 2a to 2d. Intake air is supplied from both intake boats 3a and 3b. On the other hand, the first and second cylinders of each cylinder 2a-2d
The exhaust boats/Ia and 4b are communicated with first and second exhaust passages 7c and 7d, respectively.

The second part of the engine body 1 includes opening/closing control l for low-load and high-load intake valves 5a and 5b in each cylinder 2a to 2d.
An intake side valve train Ij^8a that rotates, and an exhaust side valve train 8 that controls opening and closing of the first and second exhaust valves ('3a, (31)
1) is provided.

The intake side valve mechanism 88 is disposed on the intake side of the engine body 1 parallel to the engine body center line 9 and is connected to the timing belt 11.
0 to engine crankshirt] (not shown)
The intake side camshaft 9 has cams corresponding to the low load and high load intake valves 5a and 5b of each cylinder 2a to 2d. Surfaces 9a and 9b are formed in the same shape, and this intake side)
The rotation of the J-must shaft 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 includes an exhaust side camshaft 10 arranged on the exhaust side of the engine body 1 in parallel with the engine body center line 9 and rotationally driven by a timing belt 110.
The exhaust side camshaft 10 has cylinders 2a to 2.
Cam surface 10 corresponding to the first and second exhaust valves 6a and 6b of d
a and 10b are formed in the same shape, and the first exhaust valve 6a and the second exhaust valve 611 are opened and closed by rotation of the exhaust side forceps 1171 to 10.

The intake valve mechanism 88 includes intake valves 51 and 51 adjacent to each other for art load for the first cylinder 2a and the second cylinder 2b.
Two first variable mechanisms 11, 11 according to the present invention are provided, each of which variably controls the valve timing of the art dealer load intake valves 5b, 5b adjacent to each other in the cylinder 1, the third cylinder 2q, and the fourth cylinder 2d. Also, the exhaust side valve mechanism 8
Also in b, the valve timings of the second exhaust valves 6b, 6b of the first and second cylinders 2a, 2b which are adjacent to each other and the second exhaust valves 6b, 6b of the third and fourth cylinders 2C, 2d are respectively variable. Two second variable configurations according to the present invention for control 12.
12 are provided.

These first and second variable mechanisms 11, 12 have the same configuration as shown in an enlarged view in FIG. Rinawara,
The first variable mechanism 11 has a pressure receiving part (pressure receiving surface) whose one end (upper end) is in contact with the cam surfaces 9b, 9b of the intake side force sieve i shift 9.
13a and the high-load intake valve 5b on the opposite side, the push L [portion (suppressing surface) 1] that comes into contact with the pulse system 5S of 5b,
3b and a cylindrical sliding portion 13C connecting the two, and the tappet 13.13,
F Two insertion holes 14 that are slidably inserted and held in the downward direction
'a, 14a, and has an F surface 14b formed in an arc shape corresponding to the arc shape surface 1a of the engine main body 1, and rotates to allow the intake side camshaft 9 to rotate relative to each other. A rotating member 14 is freely supported and can rotate around the intake camshaft 9, and the rotating portion @14 is pivoted around the rotation axis of the intake camshaft 9 depending on the operating state of the engine. (The second variable mechanism 12 is a component of the first variable mechanism 11.
6S is the valve stem of the second exhaust valve 6b) 6 Pressing surface 1 of tappet 13
31) is formed into a spherical shape, and the center of the spherical surface is set at the point where the axis of rotation of the camshaft 9 intersects with the axis of the valve stem 5S when the tappet 13 is in contact with the reference inner part of the cam 9b. has been done. Forming the suppression surface as a part of the spherical surface in this way takes into consideration the rotation of the tappet 13.
= If the rotation is to be restricted, it may be an arcuate surface centered on the rotation axis of the camshaft 9.

The rotating member 14 is supported by the C intake side force musket left 9 in the center between the two fitting holes 14a, 14a, and is divided into upper and lower parts at this supported part.
61' are integrally connected.

The operating device η15 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 swing @ 17 connecting the upper end portions, and a swing @ 17 disposed at right angles to the swing shaft 17 and engaged with the center of the swing shaft 17, and formed to be able to reciprocate in the left-right direction in FIG. With the reciprocating shaft 18, for example, the rotary motion of a motor is converted into an 11 double motion, the 11 reciprocating motion 1lI118 is reciprocated in the above direction, and the rotating member 14 is rotated as described above via the swing shaft 17. and a drive device 19 for moving it. Mouth drive device 19
The rotation speed signal S1 outputted by the rotation speed sensor 20 that detects the engine rotation speed and the load signal S2 outputted by the load load sensor 21 that detects the engine load are input. During high-load, high-rotation operation, the drive device 19 is driven to move the reciprocating shaft 18 rightward in FIG. 2. Due to this reciprocating motion @18, the swing shaft 17 rotates in the same direction as the rotation direction The force is rotated in the X direction about 9.

Like normal intake and exhaust valves, the high-load intake valve 51) is slidably supported by a valve guide 32 and is biased upward, that is, in the valve-closing direction, by a valve spring 31. When the mushaf 1-0 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 inside the insertion hole 14a, it resists the biasing force of the valve spring 31. Then tappet 1
3 to open the high-load intake boat 3b (of course, the low-load intake valve 5a is also pressed in the same manner). On the other hand, when the rotating part IJ14.14 is rotated in the X direction like an upper), the tappet 13.13 also moves together with the rotating part 014.14, and the cam for a specific angular position of the intake side camshaft 9 is moved. The contact period between the surfaces 91), 9b and the tappet pressure receiving parts 13a, 13a changes to the delayed side with respect to the rotation direction X of the intake side camshaft 9, and the valve timing of each high-load intake valve 5b, 511 is delayed. be shifted to The above operation is similarly performed on the second exhaust valve 61) by the second variable mechanism 12.

Furthermore, as a feature of the present invention, guide surfaces 1b and 11+ are formed in the engine body 1 along both sides of the swinging direction (X direction) of the rotating member 14, as schematically shown in FIG. The rotation of the rotating member 14 in the X direction is regulated and guided so as not to be twisted.

Incidentally, an oil passage 9C similar to that provided in ordinary cam shirts 1 to 1 is formed in the center of the intake-side camshaft 9, and communicates with an oil pump (not shown). The oil passage 9C is connected to an oil passage 9[1 that extends in the semi-mechanical direction and opens to the cam surface 9b, and the oil passage 9d connects the cam surface 9b and the tappet 13.
Lubricating oil is introduced between the pressure receiving portion 13a and the pressure receiving portion 13a to provide lubrication. In addition, lubricating oil is introduced to the cam shirt 890, rotating member support portion 9e, camshaft bearing portion 30, etc. through another oil passage (not shown) for lubrication. The tappet 13 is attached to the pressure receiving portion 13a of the tappet 13.
An oil passage 13B that communicates with the internal cavity 13d of the tappet 1-13, and an oil passage 13B that communicates with the internal cavity 13d of the tappet 1-13.
Oil passages 13f and 13f communicating with the tappet 13 are formed respectively, and the lubricating oil that lubricates between the cam surface 9b and the tappet pressure receiving part 13a flows into the internal cavity 13d of the tappet 13 from the oil passage 13e. Later, the tappet suppressing portion 13b (
The valve stem 5S of the high-load intake valve 5h is lubricated between the pressure portion 13b and the valve stem 5S of the high-load intake valve 5h. lT to the tappet 13' on the exhaust side! J Namegawa oil supply system is also configured in the same way as the intake side, and the exhaust side camshaft 10 is provided with oil passages 10G and 10d corresponding to each oil passage of the intake side camshaft 9, and an exhaust side tappet 13 is provided. Oil passages 13'e and 13'r corresponding to the respective oil passages of the intake side tappet 13 are provided at '.

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

When the engine is running under load, the first and second variable a horizontal 11.12 are inactive, and each cylinder 2a to 2d
Low load and high load intake valves 5a.

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

That is, as shown by the solid line in FIG. 5, the valve timings of the first and second exhaust valves 6a and 6b are both controlled so that they open near the bottom dead center of the piston and then close near the top dead center. Intake valves 5a, 5 for low load and high load
The valve timing of valve b is the same as that of exhaust valves 6a and 6b.
The bar wrap period is shortened and the piston is controlled to open near the top dead center and then close near the top dead center. In addition, the high-load intake passage 7b that goes into each cylinder 2a to 2d has an on-off valve 7.
is closed by the closing operation, and air is taken in only from the low-load intake boat 3a.

On the other hand, when the engine is operating at high load and low rotation speed, the on-off valve 7 of the high load intake passage 7b is turned on, and the low load intake boat 3
In addition to the high-load intake bows 1 to 3b, air is also taken in from the high-load intake bows 1 to 3b, but both the first and second variable mechanisms 11.1'2 are set to a non-operating state, and the intake and exhaust valves 5a and 5b are 6
By shortening the A-burlap period of a and f'3b, blowback of intake air is prevented and C filling efficiency is increased. Moreover, in this case, in the exhaust stroke of each cylinder 2a to 2d, the first and second exhaust boats 4a and 4b are connected to the exhaust valves 5a and 4b, respectively.
3b, the effective frontage area for exhaust is increased compared to an engine with a single exhaust bow 1, improving scavenging efficiency and further improving the above-mentioned filling efficiency.

11- During high-load, high-speed operation of the engine, the first and second variable mechanisms 11.12 operate together, and as shown by the imaginary line in FIG. The valve timing of the second exhaust valve 6b among the valves 3a and 6b is delayed by the second variable 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 mechanism 12. The mechanism 11 is controlled to shift to the lag side.

In addition, the high-load intake passages 7b of each cylinder 2a to 2d are heard by the closing operation of the on-off valve 7, and air is also taken from the high-load intake boat 31) as in the case of high-load, low-speed operation described above. .

In addition, by lengthening the interval between the two intake valves 5a and 5b as a whole, and by extending the valve opening period to the lag side where the inertial action of the intake air is large, the filling efficiency of the intake air is improved sevenfold. The output J performance under high load and high rotation is greatly improved. Also, both exhaust valves 6a.

61) By lengthening the total valve period as a whole, the scavenging efficiency is significantly improved, and the above-mentioned filling efficiency is further improved.

Each of the above variable mechanisms 11 and 12 is a general valve mechanism (direct drive type overdrive mechanism), and Tabetsu 1 to 13 (
A rotating member 14 (14') into which the rotating member 13'(13') is inserted and held, and an operating device tf1.15 (15') which rotates the rotating member 14 (14') around the cam shaft 9 (10)
Since the structure is simple, manufacturing is easy and inexpensive.

Moreover, the variable mechanism 11. '12 variable control is based on the cam surface 91 for a specific angular position of the cam shaft 9 (10).
) (10b) and the tappet receiver H part 13a (13'a) while avoiding changes around the camshaft 9 (10), so variable control can be performed stably with good responsiveness and reliability. I can do it.

The tappet 13 (13') is connected to the rotating member 14 (
14') in the insertion hole 14a (14'a)
(It is inserted and held and slides up and down, but when transmitting cam force, it moves from the camshaft 9 (10) to the tappet 13 (13')
A lateral force (thrust force) in a direction perpendicular to the sliding direction of the tappet 13 (13') acts on the tappet 13 (13'). In addition, the cam force from the cam surface 9b (10b) of the camshaft 9 (10) is applied to the valve via the tappets 1 to 13 (13') by the rotation of the rotating portion 1,114 (1/l'). Stem 5s (6s
) with respect to the direction of the line of force transmitted to the tappet 13 (13
When the rubbing direction of the tappet 13 (13') is misaligned (during high-load, high-speed operation in the embodiment), a lateral force is similarly applied from the valve stem 5s (6s) to the tappet 13 (13'). Therefore, the rotating member 1 that holds the tappet 13 (13')
4 (14') receives the reaction force of these lateral saws, which may cause twisting of the rotating member 14 (14'). In particular, as in the above embodiment, the rotating member 14 (14,
') has its center part attached to the support part, and the insertion holes 14 on both sides thereof.
a, 1/1a (14'a, 1/1.'a) for different cylinders; Ll: 1-phase minnow intake and exhaust valve tappet 13.13 (13', 13') held In this case, the rotational member 1/l (14') is likely to be twisted due to the above-mentioned phase shift. In such a case, the reliability and stability f1 of the variable valve timing control is impaired.

However, as described above, the rotating member 14 (14') has guide surfaces 1b, 1b formed along both sides in the swinging direction.
Since the rotating member 14 (1
4') torsion is suppressed, the reliability and stability of the variable valve timing control described above can be improved and maintained in the water system, and rattling is prevented, resulting in improved durability and It is possible to reduce the 1A sound.

In the above embodiment, the present invention is applied to a dual induction type 4-valve engine having intake boats for low load and high load, but the present invention is of course applicable to other engines as well. It is. For example, as shown in FIG.
04, and in this case, the first air @102a and the second air are adjacent to each other.
Cylinder 102b, and third cylinder 102c and fourth cylinder 10
2d Nit3iT intake hose h 103.103 (or exhaust bow h 104, 104) is arranged in contact with V4, and is straddled between the intake valves (or exhaust valves) at the center S of the camshaft of the valve train. variable mechanism 11;
A variable m mechanism 111 (112) similar to 12 is disposed, and guide surfaces 101b, 101b are formed on both sides of the rotating member 114 of each variable mechanism 111 (112>) in the swinging direction. When the valve timing of the intake valve is made variable in this manner, the valve timing is set as shown in Fig. 7.In addition, when the engine is operated at high load and high rotation speed, the valve timing is set as shown by the imaginary line in Fig. 7. The valve timing of the intake valve is reliable↑1.It is shifted to the lag side with good stability.In this way, by setting the gap to the lag side where the inertial effect of the intake is large, the filling efficiency of the intake air is improved, and the intake valve timing is shifted to the lag side with good stability.
Performance is improved.

Further, in the embodiment shown in FIG. 1, the intake and exhaust valves 5b
, 6b - [Although the specific operation of the engine is set to a high-load, high-rotation time of the engine, the valve timing may be variably controlled as needed during other operations.

Furthermore, in the embodiment shown in FIG.
~2 (A31: J pair of intake boats 3a.

3b, one pair of intake valves 5a, 5b, one pair of exhaust boats 4a, 41+' j3J: and one pair of exhaust valves 6a,
6b are respectively divided into the intake side and exhaust side of the engine body 1 and arranged parallel to the center line 9 direction, and the high load intake valves 5a, 51+ are connected to each other, and the second intake valves 6b, 6 directions are connected to each other. Although they are arranged adjacent to each other, it is of course possible to use other arrangements. However, in the arrangement as in the embodiment shown in FIG.
and 2b, 2c and 2d) between high-load intake valves 5b, 51+
It is advantageous to be able to control each other and the second exhaust valves 6b and 61+ with one movable device 4M11.12.

Furthermore, in the embodiment shown in FIG.
(14') is directly supported on the camshaft j-9 (10) so as to allow mutual rotation, and the camshafts 1 to 9 (10)
) Turn around the engine body 1.
The arcuate surface 1a of the cam shirt 1-9 (10) is formed into an arcuate surface that covers the shaft center of the cam shirt 1-9 (10), and the rotating member 14 corresponds to the arcuate surface 1a.
(14') The lower surface 141) (14'b) of the rotating member 14 (14') is formed in an arc shape.
(b) may be rotated around the camshaft 9 (10) by slidingly guiding it on the arcuate surface 1a. Further, the tappet 13 (13') as in the above embodiment
A known hydraulic tappet may be used instead of , and in this case, the cam surface 91+ (1
0b) to improve its followability to Nokomushi [7 feet 9 (1
0) can be reliably transmitted to the valve stem 5S (68).

In addition, the guide surface 1b in the embodiment shown in 1)C FIG.

11) is formed integrally with the engine body 1, but it goes without saying that it may be formed as a separate member.

As explained in detail below, the engine valve timing control device of the present invention has a simple structure and can reliably and variable control the engine valve timing with good responsiveness and reliability. This greatly contributes to the easy implementation of variable control. In addition, by suppressing the twisting of the rotating member, variable control of the valve timing υ1 is possible.
No. 1 (7T) Reliability and stability can be further improved, and durability can also be improved and valve drive noise can be reduced.

[Brief explanation of drawings]

Fig. 1 shows an embodiment in which the present invention is applied to a dual-induction type four-cylinder engine. FIG. 4 is an enlarged perspective view of the variable mechanism portion of the embodiment shown in FIG. 1, FIG. 4 is a schematic plan view showing the surroundings of the rotating member, and FIG.
Explanatory diagram showing the valve timing of the pull intake and exhaust valves, No. 6
The figure shows an example in which the present invention is applied to a normal 4-cylinder engine. FIG. 7 is an explanatory diagram showing the valve timing of the intake and exhaust valves at a'3 in the embodiment of FIG. 6. 1 b...Guide surface, 5a, 5b...Intake valve, 5S
...Valve stem, 5a, 6b...Exhaust valve, 9.1
0...Camshaft, 9a, 9b, 10a, 1
01] - cam surface, 11... first variable mechanism, 12.
...Second variable mechanism, 13.13'...Tappet, 1
3a, 13'a... Tappet pressure receiving part, 13b, 13'
b... Tappet pressure receiving part, 14.1/l'-... Rotating member, 14d, 14'a... Fitting hole, 15.15'
...For operation.

Claims (1)

[Claims] (1) Receives force from the cam surface of the 7J mushitoft (pressure receiving part).The force from the cam surface is transferred to the valve stem.
i. A tappet having a pressing part that extends, a rotating member having a fitting hole into which the tappet is slidably inserted and rotatable around the camshaft, and a rotating member that is connected to the engine. A valve timing control device for an Iζ engine, comprising an operating device that swings around a camshaft (V) I- in accordance with the operating state, wherein guide surfaces are formed along both sides of the swinging direction of the rotating member. Features a covering engine valve timing control device.