JP2001132420A - Valve system for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a valve system for an internal combustion engine capable of reducing colliding speed of a movable element against a coil or a movable valve against a cylinder block seat surface, and preventing abrasion or deterioration of durability of each member or increase of noise at the time of colliding while securing secure valve opening/ closing action. SOLUTION: In this valve system for the internal combustion engine comprising a valve 112 provided in an intake passage or an exhaust passage 113, a movable element main body 116 connected to the valve 112, two coils 104, 106 for respectively driving the movable element main body 116 in a valve opening direction and a valve closing direction of the valve 112, and two spring 101, 109 for energizing an upper spring presser 102 or the valve 112 in the valve opening direction and the valve closing direction, action of the movable element main body 116 is regulated by a damping mechanism comprising a damper piston 117, an orifice 201, and a gap 202, and using working fluid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve train for an internal combustion engine that opens and closes a movable valve by driving a movable element connected to a movable valve provided in an intake passage or an exhaust passage of the internal combustion engine.

[0002]

2. Description of the Related Art As an example of a conventional valve operating device for an internal combustion engine of this type, for example, a movable valve provided in an intake passage or an exhaust passage of an internal combustion engine as described in Japanese Patent Application Laid-Open No. Hei 8-21220. A valve, a mover connected to the movable valve,
Two coils (lower coil, upper coil) for driving the mover in the valve opening direction and the valve closing direction of the movable valve, respectively;
And two springs (upper spring and lower spring) for urging the mover or the movable valve in the valve opening direction and the valve closing direction. When the mover moves downward, the movable valve is opened and movable. In some cases, the movable valve is closed when the child moves upward.

In a state where no current flows through the upper coil and the lower coil, the mover is positioned at a position substantially evenly separated from the upper and lower coils (ie, the neutral position) by the upper and lower springs provided above and below the mover. You are being biased to.

When the engine is opened, the current supplied to the upper coil is turned off to open the mover (attracted by the upper coil), and the force stored in the upper spring and the lower spring is released. When the vehicle approaches the lower coil, a current is caused to flow through the lower coil at a predetermined timing to cause the movable element to be attracted to the lower coil, thereby opening the movable valve.

When the valve is closed from this state, the current supplied to the lower coil is turned off to release the movable element that has been attracted to the lower coil, and the movable element stores the force stored in the upper spring and the lower spring. When the vehicle approaches the upper coil, a current is applied to the upper coil at a predetermined timing to cause the movable element to be attracted to the upper coil, thereby closing the movable valve.

[0006] By repeating the above valve opening and closing operations, the opening and closing operation of the movable valve can be performed efficiently and at a desired timing using the energy stored in the upper spring and the lower spring.

[0007]

However, the above prior art has the following problems.

That is, for example, when the valve is opened from the closed state, the electromagnetic attraction force of the lower coil acts in a direction (= downward) to attract the mover to the lower coil, while the spring force of the upper spring and the lower spring is movable. Acts in the direction of returning the child to the neutral position (= upward or downward). Therefore, in the latter half of the operation after passing the neutral position in this valve opening operation,
The electromagnetic attraction force and the spring force act in opposite directions.

In general, the electromagnetic attraction force of the lower coil increases in inverse proportion to the square of the distance from the coil, whereas the spring force of the upper and lower springs is almost equal to the distance from the neutral position. It has the property of increasing proportionally.
As a result, when the valve is opened from the closed state, first, the mover starts to separate from the upper coil by the above-described spring force toward the neutral position (downward). Thereafter, the mover is further accelerated downward by the above-mentioned spring force, but after passing the neutral position, the spring force returns to the neutral position (upward).
And gradually decelerate. here,
By appropriately setting the supply current to the lower coil, when the mover approaches the lower coil to some extent, the lower coil applies an electromagnetic attraction force downward, and the mover moves the mover against the above upward spring force. It can be adsorbed to the lower coil.

When the valve is closed from the open state, the operation is the same as above except that the valve is turned upside down.

At this time, in order to reliably perform the valve opening operation and the valve closing operation, in order to overcome the spring force as described above, the supply current to the lower coil (or the upper coil) is increased to some extent to increase the attraction force. Need to secure. However, in this case, in the immediate vicinity of the lower coil (or the upper coil) immediately before the end of the valve opening operation (or the valve closing operation), the attractive force of the coil becomes relatively large, and the speed of the mover increases. It becomes difficult to reduce the collision speed of the lower coil (or the upper coil) or the collision speed between the movable valve and the cylinder block seating surface, leading to wear and durability of the mover and the coil, or the movable valve and the seating surface. Or increase the noise at the time of collision.

Further, at this time, after the mover collides with the lower coil (or the upper coil), it bounces on the surface thereof and tries to move away from the coil again. To prevent this again, a stronger magnetic attraction force is required. Therefore, it becomes difficult to reduce the coil supply current. As a result, power consumption is increased and a large-scale power supply is required, so that the mountability in a vehicle or the like is deteriorated and the overall efficiency of the engine is reduced.

An object of the present invention is to reduce the collision speed between a mover and a coil or a movable valve and a cylinder block seating surface while ensuring a reliable valve opening / closing operation, to reduce wear of each member,
It is an object of the present invention to provide a valve train for an internal combustion engine that can prevent deterioration in durability and increase in noise at the time of collision.

[0014]

(1) In order to achieve the above object, the present invention relates to a movable valve provided in an intake passage or an exhaust passage of an internal combustion engine, and a movable element connected to the movable valve. Two coils for driving the movable element in the valve opening direction and the valve closing direction of the movable valve, and two springs for urging the movable element or the movable valve in the valve opening direction and the valve closing direction. A damping mechanism for regulating the operation of the mover is provided.

The movable valve of the internal combustion engine has two coils and two
By driving the mover in the valve opening direction or the valve closing direction by the two springs, the valve opening operation or the valve closing operation is performed, and the intake passage or the exhaust passage is opened and closed. Here, in order to reliably perform the valve-opening operation and the valve-closing operation, in order to overcome the spring force of the two springs normally arranged so that the spring force is directed to the neutral position and to attract the movable element, the coil ( It is necessary to increase the supply current to the lower coil or the upper coil to some extent to secure the attraction of those coils. In this case, as it is, immediately before the end of the valve opening operation (or the valve closing operation), in the vicinity of the lower coil (or the upper coil), the attraction force of the coil becomes relatively large, and the speed of the mover becomes large. There is a possibility that it is difficult to reduce the collision velocity between the lower coil (or upper coil) and the collision velocity between the movable valve and the cylinder block seating surface of the internal combustion engine, for example.

Therefore, in the present invention, a damping mechanism for regulating the operation of the mover is provided. For example, at the time of the opening operation of the movable valve, the movable valve is positioned at a predetermined distance from the end point of the operation in the valve opening direction (a very small position of the lower coil). When the actuator approaches the vicinity, for example, a position where the electromagnetic attraction force of the lower coil exceeds the upward spring force of the two springs), the operation restriction in the valve opening direction is started. At the time of the valve closing operation, the movable valve is located at a predetermined distance from the end point of the valve closing direction operation (in the vicinity of the upper coil, for example, the position where the electromagnetic attraction force of the upper coil exceeds the spring force downward of the two springs). When the distance approaches, the operation restriction in the valve closing direction is started. As a result, the collision speed between the mover and the lower coil (or the upper coil) or the collision speed between the movable valve and the cylinder block seating surface can be reduced to reduce the impact, so that the mover and the coil or the movable valve can be reduced. In addition, it is possible to prevent wear of the seating surface and decrease in durability, and further reduce noise at the time of collision.

In addition, since re-separation due to bouncing after collision with the coil is reduced and the coil supply current can be reduced, the power source can be reduced in size, the mountability on a vehicle or the like can be improved, and the overall efficiency of the engine can be improved. can do.

(2) In the above (1), preferably,
The damping mechanism starts the operation regulation in the valve opening direction when the movable valve approaches a position at a predetermined distance from the end point of the valve opening direction operation during the valve opening operation of the movable valve, In the closing operation of the movable valve, when the movable valve approaches a position at a predetermined distance from the end point of the operation in the valve closing direction, the operation restriction in the valve closing direction is started.

(3) In the above (1) or (2), preferably, the damping mechanism includes a fluid passage through which a fluid flows, and a throttle means provided in the fluid passage. The movement of the mover is restricted by restricting the movement of the fluid in the fluid passage accompanying the operation in the valve opening direction or the valve closing direction by the restrictor.

(4) In the above (3), more preferably, the fluid passage of the damping mechanism is a substantially closed space, and the fluid flows in the substantially closed space in one direction via the throttle means. Regulating the movement of the mover in the valve opening direction,
When the fluid flows in the substantially closed space in the other direction via the throttle means, the movement of the mover in the valve closing direction is restricted.

As described above, by restricting the operation of the movable valve by utilizing the flow of the fluid through the throttle means in one substantially closed space, the fluid is caused to flow in one direction to open the movable element. While performing the function of regulating the movement in the direction,
Preparation (initialization) for the operation restricting function of the mover in the valve closing direction thereafter can be executed. Similarly, the flow of the fluid in the other direction restricts the operation of the mover in the valve closing direction. And at the same time, the preparation (initialization) for the operation restriction function in the direction of opening the movable element valve can be executed.
That is, with a simple structure, the mover operation restriction function can be efficiently used alternately according to the opening and closing of the movable valve.

(5) In the above (4), more preferably, the damping mechanism further includes a first piston member provided so as to engage with the movable element and move with the movable element, and the fluid passage includes: It is formed between the first piston member and the mover.

(6) In the above (4), preferably, the damping mechanism is arranged such that the movable element comes into contact with the movable valve when the movable valve is near the end point in the valve opening direction and near the end point in the valve closing direction. And a second piston member provided at a position such that the fluid passage is at least partially provided on a side of the second piston opposite to the armature contact side.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIG. FIG. 1 is a longitudinal sectional view showing the entire structure of the valve train of an internal combustion engine according to the present embodiment. In addition,
This drawing shows a state in which a valve 112 (described later) is performing a valve opening operation from a valve closed state (a state in which operation regulation by a damping mechanism is started).

The valve train shown in FIG. 1 is provided with an intake passage (or exhaust passage) 113 of a cylinder head 111 of an engine.
A valve (movable valve) 112 is provided between the combustion chamber 121 and the combustion chamber 121, and the valve 112 is urged by a lower spring 109 in a direction in which the intake passage is closed (in this embodiment, upward).

A retainer 108 is provided above the lower spring 109, and the retainer 108 is attached to the valve 112 by a cotter pin 107. Thereby, the lower spring 109
Urges the valve 112 upward as described above.

The valve 112 is provided with a through hole 11 provided in a portion of the cylinder head 111 that is below the lower spring 109.
1a is disposed via a valve guide 110. A mover shaft 115 is provided above the valve 112 so as to push it down.
16 are formed integrally. In addition, the mover shaft 1
15 to hold the upper coil 104 and the lower coil 1
06 is provided with mover shaft guides 118 and 114, respectively. These upper coil 104 and lower coil 1
Numeral 06, when excited by a supply current from a power source (not shown), generates an electromagnetic attraction force for attracting the mover body 116 upward and downward, respectively.

At this time, the mover main body 116 is
A spacer 105 is provided between the upper coil 104 and the lower coil 106 to define a gap between the upper coil 104 and the lower coil 106. Furthermore, the mover body 1
The upper shaft 1 which forms a part of the mover
19 and an upper spring retainer 102 formed integrally therewith, which are urged downward by an upper spring 101.

A cover 103, an upper spring retainer 122, and a lock nut 123 are mounted on the upper portion of the upper coil 104 to urge the upper spring 101 downward. Further, inside the cover 103, a displacement sensor 120 for measuring a distance to the upper shaft 102 and checking a displacement of the mover with the distance is attached.

The main part 116 of the mover, which is a main part of this embodiment,
FIG. 2 is an enlarged view of a portion A in FIG.

In FIG. 2 and FIG.
A damper piston 117 is engaged with a piston mounting hole 116a provided in the piston, and a space between the mover main body 116 and the damper piston 117 is filled with a working fluid (for example, air). Is formed. An orifice 201 is provided near the center of the mover body 116 in the thickness direction, and restricts the working fluid when the damper piston 117 operates to regulate the flow amount. Although not particularly shown,
Between the mover main body 116 and the damper piston 117,
A well-known seal ring is provided to prevent leakage of the working fluid, whereby the gap 202 forms a substantially closed space.

FIG. 3 shows an example of the configuration of the damper piston 117. In FIG. 3, the damper piston 117 is
The lower part 503 is divided into an upper part 502 and a lower part 503, and a retaining part 504 provided at a lower end of the upper part 502 is press-fitted into the inside of the lower part 503 (see a broken arrow in the drawing). Thus, the mounting can be easily performed simply by press-fitting from both sides across the upper and lower surfaces of the mover body 116.

The upper and lower end surfaces of the damper piston 117 (ie, the upper surface of the upper portion 502 and the lower surface of the lower portion 503).
Is composed of a sheet 501 in which elastic rubber and a soft magnetic material such as iron are mixed. Thereby, (besides the collision mitigation and the noise increasing effect by the original operation of the damping mechanism of the present invention described later), the impact when the piston 117 collides with the coil 104 or 106 is further reduced, so that the noise can be further suppressed. Considered. Further, since the magnetic material is mixed, it is possible to reduce the size of the valve operating mechanism without impairing the magnetic attraction of the mover main body 116 and the coils 104 and 106 while having the damping mechanism.

It should be noted that the system relating to the valve train of the present embodiment configured as described above can be configured as shown in, for example, a block diagram of FIG. That is, the engine rotation angle sensor 305 and the engine speed sensor 30
6. Accelerator opening sensor 307, engine water temperature sensor 3
08, a gear position sensor 309, and a computer 310 performs a predetermined calculation based on information (output signal) from the displacement sensor 120 and the like attached to the valve mechanism 302 to determine the operation timing of the valve mechanism 302. Then, the operation timing signal is output to the current control circuit 303. The current control circuit 303 is based on the power supplied from the power supply 304,
02 generates a current waveform necessary for the operation of the valve operating device 302.
The drive current is supplied to the upper coil 104 and the lower coil 106 of FIG.

In the above, the mover body 116
, The upper shaft 119, the upper spring retainer 102, and the mover shaft 115 constitute a mover described in each claim. Further, a damper piston 117 constitutes a first piston member which is provided in engagement with the mover and moves together with the mover, the gap 202 constitutes a fluid passage through which fluid flows, and the orifice 201 forms a fluid passage. The diaphragm means provided is constituted. The damper piston 117, the gap 202, and the orifice 201 form a damping mechanism that regulates the operation of the mover.

Next, the operation and operation of this embodiment will be described below.

(1) Adjustment of Neutral Point Before the valve opening and closing operations are performed, a neutral point adjusting operation is required as a preparation stage.

That is, the upper coil 104 and the lower coil 10
6 is not energized, the mover body 11
6 is urged downward and upward by the upper spring 101 and the lower spring 109, respectively.
And the lower coil 106 is located almost in the middle (neutral point or neutral position).

The adjustment of the neutral point is performed by rotating the upper spring retainer 122 attached to the cover 103 to move it up and down, and adjusting the amount of contraction of the upper spring 101. The lock nut 123 is provided to prevent the upper spring retainer 122 from being accidentally moved after the adjustment.

(2) Initialization Setting In order to open and close the valve 112, it is necessary to fix the valve 112 to one of the open state and the closed state from the neutral state by the initialization means. The initialization may be performed by a method in which a large current is applied to one of the upper and lower coils 104 and 106, or alternatively, the upper coil 104 and the lower coil 106 are alternately energized at the same time interval as the resonance period of the movable part. Resonance is caused in the main body 116 to gradually increase the amplitude, and the upper coil 104 or the lower coil 1
06 may be adopted.

(3) Basic operation of valve opening and closing The valve closing state, that is, the movable element main body 116 is
To open the valve from the state where it is adsorbed on the upper coil 1
The current flowing through the coil 04 is turned off, and the mover body 116 attracted to the upper coil 104 is opened. Thereby, the spring force stored in the upper and lower springs 101 and 109 causes
The mover main body 116 starts moving downward. Then, when the mover main body 116 approaches the lower coil 106, a current of a predetermined value is supplied to the lower coil 106, so that the mover 116 main body is attracted to the lower coil. At this time, it takes a certain time due to the coil inductance and the like from when the current of the lower coil 106 is turned on to when the current value of the lower coil 106 becomes a predetermined value. Is set earlier in anticipation of this time difference. The predetermined current value at the time of suction is set to a large current (this is referred to as a catching current value) so that vibration and bounce caused by the collision reaction of the mover can be suppressed, and once the suction is performed and the bounce is suppressed. Reduces the current value in order to reduce the current consumption flowing through the lower coil 106 (this is called a hold current). The catching current is, for example, about 5 to 10 of the hold current.
Double it.

After this state is continued during the intake or exhaust stroke of the engine, the relationship between the upper coil 104 and the lower coil 106 is exchanged and the same operation is performed, whereby the valve closing operation from the open state can be performed. .

By repeating the above-described valve opening and closing operations, the energy stored in the upper spring 101 and the lower spring 109 can be used to open and close the valve 112 at an arbitrary timing and efficiently. Can be.

(4) Operation and Operation of the Damping Mechanism of the Present Embodiment The valve train of the present embodiment uses the above-described damping mechanism to secure the valve opening and closing operations while maintaining the movable element main body 116 in the up-down direction. This is to reduce the collision speed between the coils 104 and 106 or the valve 112 and the seating surface of the cylinder block 111. Hereinafter, this operation will be described in detail.

As described above, the valve 112 drives the mover main body 116 in the valve opening direction or the valve closing direction by using the spring force of the upper and lower springs 101 and 109 by alternately turning off the upper and lower coils 104 and 106. As a result, the valve opening operation or the valve closing operation is performed, and the intake passage or the exhaust passage is opened and closed. Here, in order to reliably perform the valve opening operation and the valve closing operation, as described above, the vertical springs 101 and 1 moving toward the neutral point are used.
In order to overcome the spring force of 09 and attract the mover, the supply current value (the catching current value) to the upper and lower coils 104 and 106 is increased to some extent to increase the coil 10
It is necessary to secure a suction force of 4,106.

This will be described with reference to FIGS. 5 and 6 taking the valve opening operation as an example.

FIG. 5 shows the movable body 1 during the valve opening operation.
FIG. 16 is a diagram illustrating an operation behavior of No. 16; The horizontal axis is time t,
The vertical axis represents the upward distance h with the neutral point as the origin. Further, a curve a shown by a solid line shows a behavior in the valve train of the present embodiment having a damping mechanism, and a curve b shown by a broken line shows a behavior of a comparative example in which the damping mechanism is simply removed from the valve train of the present embodiment. The behavior is shown. Also, FIG.
FIG. 7 is a diagram illustrating a transition of a current supply value to a lower coil during a valve opening operation. The horizontal axis represents the time t corresponding to FIG.
And the vertical axis represents the current value. A curve a 'shown by a solid line shows a behavior in the valve gear of the present embodiment,
A curve b 'shown by a broken line shows the behavior of the comparative example.

In FIG. 5, in the comparative example having no damping mechanism, as shown by the curve b, the mover main body 116 released from the upper coil 104 has the vertical springs 101 (downward) toward the neutral point (downward). It is accelerated by the spring force of 109 and starts moving downward. Thereafter, the mover main body 116 is further accelerated downward by the spring force, but after passing the neutral point, the spring force acts in a direction (upward) to return to the neutral point, and the mover 116 Slow down gradually.

At this time, as indicated by a curve b 'in FIG. 6, the supply current to the lower coil 106 is started shortly before the mover main body 116 passes the neutral point.
At a stage where the mover main body 116 approaches the lower coil 106 to some extent (in this case, the mover main body 116
(At a point c which is closer to the distance hc), the downward electromagnetic attraction force of the lower coil 106 is applied, and the mover main body 116 can be attracted to the lower coil 106 against the above upward spring force (FIG. 5 curve b).

Here, as shown in FIG.
The electromagnetic attraction force of No. 6 is generally about 2 distances from the coil.
The upper and lower springs 101, 1 increase in inverse proportion to the power.
09 has the property of increasing almost in proportion to the distance from the neutral point. That is, on the side closer to the upper coil 104 than the neutral point, the spring forces of the upper and lower springs 101 and 109 are working toward the neutral point, and the lower coil 10
The magnetic attraction force of No. 6 hardly acts because it is far away. In the vicinity of the neutral point, since both the spring force and the magnetic attraction force are small, the mover main body 116 passes through this portion with the kinetic energy obtained when it was on the upper coil 104 side. Further, when the mover body 116 approaches the lower coil 106, the spring reaction force increases in proportion to the distance, whereas the magnetic attraction force increases in inverse proportion to the square of the distance. Become.

As a result, in the case of the comparative example described above, the lower coil 106 is located very near the end of the valve-opening operation (for example, the upward spring force of the upper and lower springs 101 and 109 and the downward magnetic attraction force of the lower coil 106 are smaller). Figure 5 to be equal
And when the distance from the lower coil 106 of the mover main body 116 to less than hc exceeds the point c shown in FIG. 7), the attraction force of the lower coil 106 becomes too large and the speed of the mover main body 116 becomes excessively high. Becomes

Therefore, the mover main body 116 is
6 (corresponding to the point d in FIG. 5), the collision speed (or the collision speed between the valve 112 and the seating surface of the cylinder block 111) increases, and the armature body 116 and the lower coil 106 (or the valve 112 and This leads to wear of the seating surface) and reduced durability, and further increases noise at the time of collision.

Further, the mover main body 116 once collides with the lower coil 106 and then bounces on the surface thereof to form the lower coil 1.
06 (bound) again, but in the comparative example, the collision speed is high, so the curve b in FIG.
As shown in the figure, the bounce after the collision is large and the bounce time is long. Therefore, in order to hold the movable coil body 116 on the lower coil 106 by pressing it down, a considerably large catching current Ic 'is required as shown by a curve b' in FIG. A large-scale power source is required, which deteriorates the mountability on a vehicle or the like and also lowers the overall efficiency of the engine.

The catching current Ic '
Can be reduced, the attraction force of the lower coil 106 can be reduced, and the collision speed when the mover body 116 collides with the lower coil 106 can be reduced. In this case, a curve e indicated by a dashed line in FIG. As described above, when the mover main body 116 once collides with the lower coil 106 and then bounces, the mover main body 116 cannot be re-adsorbed, and vibrates around the neutral point position as the center of amplitude, and as a valve operating device, Stop functioning.

Therefore, in the present embodiment, the above-mentioned adverse effects are prevented by providing the above-mentioned damping mechanism. As shown by a curve a in FIG. 5, the above-mentioned point c (= lower coil 10 of mover body 116)
The position at which the distance from 6 is hc, in other words, the valve 112
(A position at a predetermined distance from the end point of the valve opening direction operation), the behavior is the same as that of the comparative example shown by the curve b in FIG. 5, but at the point c, the damping mechanism starts operating.

That is, when the point c is reached (the lower surface of the mover main body 116 has not yet been attracted to the upper surface of the lower coil 106), it is provided in engagement with the mover main body 116 together with the mover main body 116. The damper piston 117 that has descended contacts the upper surface of the lower coil 106 first. FIG. 1 and FIG. 2 described above show the state at this time.
As shown in FIG. 2, in this state, the orifice 2 in the gap 202 between the mover body 116 and the piston 117
Reference numeral 01 denotes an upper portion, and the working fluid is mainly filled in the lower portion 202 a of the orifice 201.

Thereafter, the mover main body 116 is
6, the space (gap) 202 filled with the working fluid is compressed as shown in FIG.
Is forcibly moved upward through the orifice 201. At this time, by setting the cross-sectional area of the orifice 201 appropriately small, the amount of the working fluid that can move per unit time can be reduced, so that the downward movement of the mover body 116 is regulated to a constant slow speed. While the mover main body 116 is thus decelerated, the working fluid that has been filled in the gap lower portion 202a eventually becomes the orifice 201 as shown in FIG.
And moves to the upper portion 202b of the gap, and the lower surface of the mover body 116 is attracted to the upper surface of the lower coil 106.

By the damping action of the above damping mechanism,
In the present embodiment, as shown by the curve a in FIG. 5, when the mover main body 116 collides with the lower coil 106, the speed is sufficiently reduced. (And collision between the valve 112 and the seating surface of the cylinder block 111) can be reduced.

Further, as shown by a curve a in FIG. 5, the bound after the lower coil 106 collides with the lower coil 106 of the mover main body 116 is reduced, and the time of the bound is also reduced. As a result, as shown by the curve a 'in FIG.
The value of c can be reduced, and power consumption can be reduced.

Further, the operation of the damping mechanism is started by the upward spring force of the upper and lower springs 101 and 109 and the lower coil 1.
On the side closer to the neutral point than the above-mentioned point c at which the downward magnetic attraction force by 06 becomes equal, the upper and lower springs 101, which return to the neutral point side at the moment when the mover main body 116 is decelerated by the damping mechanism, There is a possibility that the spring force of 109 becomes larger and the mover main body 116 rebounds toward the neutral point side, and the valve opening operation fails. In the present embodiment,
Assuming that the thickness of the mover body 116 is hk and the thickness of the damper piston 117 of the damping mechanism is hd, it is set in advance so that hd ≦ hk + hc. Thus, the above-described possibility is prevented, and the valve opening operation can be reliably performed.

Further, since the operation of the valve 112 is regulated in the gap 202, which is a substantially closed space, by using the flow of the working fluid through the orifice 201, the valve 112 is movable as described above when the valve is opened. When the damping action of the slave main body 116 is completed, the working fluid moves to the gap upper portion 202b through the orifice 201, and the upper end of the damper piston 117 is in a state of protruding above the mover main body 116. Thereby, at the time of the next valve closing operation, the operation at the time of the above-described valve opening operation is immediately performed in the same manner with the vertical relationship completely reversed, and the working fluid is moved to the gap lower portion 202a through the orifice 201, and the movable element is moved. Body 116
The damping mechanism can be operated so as to suppress the collision speed between the coil and the upper coil 104. That is, when the damping action at the time of the valve-opening operation (the action regulating action of the mover main body 116) is completed, the preparation for the start of the damping action at the next valve-closing operation (initialization) is automatically completed, and the valve-closing operation is completed. When the damping action at the time is completed, the state is automatically ready to start the damping action at the next valve opening operation. In this way, with a simple configuration, the damping function of the paired valve-closing side or valve-opening side is alternately reset by using the kinetic energy of the mover main body 116 at the time of valve opening or valve closing, and It can be prepared for closing or opening the valve.

As described above, according to the valve train of this embodiment, the mover main body 116 is attached to the upper and lower coils 104 and 106 by the damping effect of restricting the flow of the working fluid in the gap 202 by the orifice 201. Impact at the time of collision can be reduced. Therefore, it is possible to prevent wear and durability of the mover main body 116 and the upper and lower coils 104 and 106, or the valve 112 and the seating surface, and further reduce noise at the time of collision.

The upper and lower coils 10 of the mover body 116
Since the bounce after the 4,106 collision is reduced and the time during which the bounce is reduced, the value of the catching current Ic can be reduced, and power consumption can be reduced. Therefore, it is possible to reduce the size of the power supply, improve the mountability on a vehicle or the like, and improve the overall efficiency of the engine.

In the first embodiment, the shape of the damper piston 117 is not limited to the cylindrical shape as shown in FIG. 3, and if the thickness of the piston 117 satisfies the above conditions, The number of pistons and the like may be changed. Similarly, the dimensions and shapes of the upper and lower coils 104 and 106 and the mover main body 116 are not limited to those described above (or shown in the drawings), but may be other. In these cases, a similar effect is obtained.

FIGS. 10 to 13 show a second embodiment of the present invention.
This will be described below. This embodiment is an embodiment of a valve train provided with a damping mechanism having a different structure. The same parts as those in the first embodiment are denoted by the same reference numerals, and the description will be appropriately omitted.

FIG. 10 is a longitudinal sectional view showing the entire structure of the valve gear of the internal combustion engine according to the present embodiment, FIG. 11 is an enlarged view of a portion B in FIG. 10, and FIG. FIG. 13 is a diagram illustrating a state in which the mover main body has moved further downward from the state shown in FIG. 13, and FIG. 13 illustrates a state in which the mover main body has moved further downward from the state illustrated in FIG. FIGS. 1 and 2 of the first embodiment,
FIG. 10 is a diagram corresponding to FIGS. 8 and 9.

In FIGS. 10 to 13, the valve gear of this embodiment has the same basic configuration as the valve gear of the first embodiment, but differs in the following points.

That is, the damping mechanism comprises an upper damper piston 40 provided below the upper coil 104 so as to be vertically movable.
2, a lower damper piston 403 provided on the upper portion of the lower coil 106 so as to be vertically movable, and a lower damper piston 4
02, 403, and the communication pipe 4
01 and an orifice 201 provided in the middle of the valve.

The upper and lower damper pistons 402, 403
As will be described later, it is provided at a position where the mover main body 116 comes into contact when the valve 112 is near the end point in the valve opening direction and near the end point in the valve closing direction. In addition, gaps 404 and 405 formed between the upper and lower coils 104 and 106 and the damper pistons 402 and 403 (in other words, the gaps 404 and 405 formed between the upper damper piston 402 and the lower damper piston 403 on the side opposite to the movable body), and the inside of the communication pipe 401. In
The working fluid (eg, air, oil, etc.) is filled, and between the upper and lower damper pistons 402, 403 and the upper and lower coils 104, 106, the working fluid is prevented from leaking and the pistons 402, 403 move smoothly. to be able to do,
A known oil seal 203 is provided.

In the above description, the upper and lower damper pistons 402 and 403 come into contact with the movable element when the movable valve is near the end point in the valve opening direction and near the end point in the valve closing direction. The second piston member provided at such a position is provided, the gaps 404 and 405 and the communication pipe 401 constitute a fluid passage through which the fluid flows, and the orifice 201 constitutes a throttle means provided in the fluid passage. And these upper and lower damper pistons 402, 40
3. The gaps 404 and 405, the communication pipe 401, and the orifice 201 constitute a damping mechanism that regulates the operation of the mover.

In this embodiment having the above-described structure, the damping is performed when a predetermined distance (position corresponding to the point c) is reached from the end point of the valve 112 in the valve opening direction, as in the first embodiment. The mechanism starts operating.

That is, when the operation start point is reached (the lower surface of the mover main body 116 has not yet been attracted to the upper surface of the lower coil 106), the lower surface of the mover main body 116 is first placed on the upper surface of the lower damper piston 403. Abut Figure 1 above
0 and FIG. 11 are diagrams showing the state at this time.

Thereafter, the mover main body 116 is
6, the lower damper piston 40 moves downward due to the magnetic attraction force and inertia of the lower damper piston 40, as shown in FIG.
3 is depressed, the gap 405 below the lower damper piston filled with the working fluid is compressed, and pressure is generated in the working fluid. As a result, the working fluid filled in the gap 405 passes through the communication pipe 401 and passes through the upper damper piston 40.
Flowing into the gap 404 on the second side (see arrow A in FIG. 12)
Since the flow rate is regulated by the orifice 404 in the communication pipe 401, the lower piston 403 moves at a predetermined speed.

As a result, similarly to the first embodiment, the downward movement of the mover main body 116 is regulated to a constant slow speed. Finally, as shown in FIG. 13, a part of the working fluid filled in the gap 405 passes through the orifice 201 and the upper damper piston 402
It moves to the upper gap 404, and the lower surface of the mover main body 116 is attracted to the upper surface of the lower coil 106. At the same time, the communication pipe 40
The upper damper piston 402
Is a predetermined height above the upper coil 104 (see FIGS. 5 and 7).
Is set downward so that the impact when the mover body 116 collides with the upper coil 104 in the next valve closing operation can be reduced.

With the damping action of the damping mechanism as described above,
According to the present embodiment, similarly to the first embodiment, the impact (and the collision between the valve 112 and the seating surface of the cylinder block 111) when the mover body 116 collides with the upper and lower coils 104 and 106 can be reduced, and the movable body can be moved. The bound after the collision of the upper and lower coils 104 and 106 of the child main body 116 is reduced, the value of the catching current is reduced, and the power consumption can be reduced.

Although the first embodiment and the second embodiment have been described separately, it goes without saying that the first and second embodiments may be combined.

[0077]

According to the present invention, the collision speed between the mover and the coil or the movable valve and the cylinder block seating surface is reduced while ensuring reliable valve opening / closing operation, and wear and durability of each member are reduced. It is possible to prevent a decrease in performance and an increase in noise at the time of collision.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view illustrating an entire structure of a valve gear of an internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a portion A in FIG.

FIG. 3 is a diagram illustrating an example of a configuration of a damper piston illustrated in FIG. 2;

FIG. 4 is a block diagram showing a system related to the valve train shown in FIG. 1;

FIG. 5 is a diagram illustrating an operation behavior of the mover main body during a valve opening operation.

FIG. 6 is a diagram illustrating a transition of a current supply value to a lower coil during a valve opening operation.

FIG. 7 is a diagram showing a change in magnitude of the electromagnetic attraction force of the lower coil and the spring force of the upper and lower springs according to the distance from the upper and lower coils.

FIG. 8 is a diagram showing a state in which the mover main body has moved further downward from the state shown in FIG. 2;

FIG. 9 is a view showing a state in which the mover body has moved further downward from the state shown in FIG. 8 and has come into contact with the lower coil.

FIG. 10 is a longitudinal sectional view illustrating an entire structure of a valve gear of an internal combustion engine according to a second embodiment of the present invention.

11 is an enlarged view of a portion B in FIG.

FIG. 12 is a view showing a state in which the mover main body has moved further downward from the state shown in FIG. 11;

13 is a view showing a state in which the mover body has moved further downward from the state shown in FIG. 12 and has come into contact with the lower coil.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 101 Upper spring 102 Upper spring presser (movable element) 104 Upper coil 106 Lower coil 109 Lower spring 111 Cylinder head 112 Valve (movable valve) 113 Intake passage or exhaust passage 115 Mover shaft (movable element) 116 Mover main body (movable element) 117) Damper piston (first piston member, damping mechanism) 119 Upper shaft (movable element) 201 Orifice (throttle means, damping mechanism) 202 Gap (fluid passage, damping mechanism) 301 Engine 302 Body valve device 401 Communication pipe (fluid passage) , Upper damper piston (second piston member, damping mechanism) 403 lower damper piston (second piston member, damping mechanism) 404 gap (fluid passage, damping mechanism) 405 gap (fluid passage, damping mechanism)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masayoshi Momono 2520 Oita Takaba, Hitachinaka-shi, Ibaraki Co., Ltd. Within the Hitachi, Ltd. Automotive Equipment Group (72) Inventor Kazuhiro Kurisu 2520 Oita Takaba, Hitachinaka-shi Ibaraki Co., Ltd. F-term in Hitachi, Ltd. Automotive Equipment Group (reference) 3H106 DA07 DA25 DB02 DB12 DB26 DB32 DC02 DC17 EE19 FA08 GC11 KK17

Claims (6)

[Claims] 1. A movable valve provided in an intake passage or an exhaust passage of an internal combustion engine, a movable element connected to the movable valve, and the movable element driven in a valve opening direction and a valve closing direction of the movable valve, respectively. A valve actuation device for an internal combustion engine having two coils that actuate the movable element or the movable valve in the valve opening direction and the valve closing direction, the damping mechanism restricting the operation of the movable element. A valve train for an internal combustion engine, comprising: 2. The valve operating apparatus for an internal combustion engine according to claim 1, wherein the damping mechanism is configured such that when the movable valve is opened, the movable valve approaches a position at a predetermined distance from an end point in the opening direction of the movable valve. At the same time, the operation regulation in the valve opening direction is started, and at the time of the closing operation of the movable valve, when the movable valve approaches a position at a predetermined distance from the end point of the valve closing direction operation, the valve closes. A valve actuation device for an internal combustion engine, wherein the operation regulation in the direction is started. 3. A valve train for an internal combustion engine according to claim 1, wherein said damping mechanism comprises: a fluid passage through which a fluid flows;
A restrictor provided in the fluid passage, wherein the movement of the fluid in the fluid passage accompanying the operation of the mover in the valve opening direction or the valve closing direction is restricted by the restrictor. A valve train for an internal combustion engine, which regulates the operation of a mover. 4. A valve train for an internal combustion engine according to claim 3, wherein the fluid passage of said damping mechanism is a substantially closed space, and said fluid flows in said substantially closed space in one direction via said throttle means. When flowing, the movement of the mover in the valve opening direction is regulated, and when the fluid flows in the substantially closed space in the other direction via the throttle means, the movement of the mover in the valve closing direction is restricted. A valve train for an internal combustion engine, which is regulated. 5. A valve train for an internal combustion engine according to claim 4, wherein said damping mechanism further includes a first piston member provided to engage with said mover and move with said mover, and said fluid passage. Is formed between the first piston member and the movable element. 6. The valve train for an internal combustion engine according to claim 4, wherein said damping mechanism is configured to move said movable element when said movable valve is near said end point in said opening direction and near said end point in said closing direction. And a second piston member provided at a position where the fluid comes into contact with the second piston member, and at least a part of the fluid passage is provided on a side of the second piston opposite to the movable element contact side. A valve train for an internal combustion engine.