JP2002070515A - Electromagnetic driving device for valve body of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such a problem in an electromagnetic driving device for driving the opening/closing of the suction valve that the device itself is enlarged if the valve element lifting amount of a suction valve or the like is formed to be adjusted by changing the position of an electromagnetic coil wound on an iron core for driving a moving piece. SOLUTION: This electromagnetic driving device for a valve element of an internal combustion engine acts the electromagnetic force generating when voltage is applied to the electromagnetic coil wound on an iron core to a moving piece locating in a space within the iron core, and drives the valve element of the internal combustion engine with a driving shaft interlocking with the moving piece. The moving piece is formed so that the thickness is changeable according to the inner dimension of the space within the iron core.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve body electromagnetic drive device for driving, for example, an intake valve and an exhaust valve of an internal combustion engine for an automobile.

[0002]

2. Description of the Related Art Conventionally, there has been known a valve body electromagnetic drive device that drives an intake valve or an exhaust valve, which is a valve body of an internal combustion engine, by using an electromagnetic force generated by an electromagnetic coil. This type of electromagnetic drive device for a valve element includes an iron core, an electromagnetic coil wound around the iron core, a movable element that reciprocates by an electromagnetic force generated in the electromagnetic coil, and a reciprocating movable element fixed to the iron element. The apparatus includes a drive shaft movably supported to open and close the intake and exhaust valves, and a displacement sensor for detecting a movement position of the drive shaft.

In recent years, an engine called variable valve timing in which the opening timing of an intake valve or an exhaust valve and the lift amount thereof are variable has been put to practical use. In order to realize such a configuration in which the lift amount of the valve body at the variable valve timing can be changed in the valve body electromagnetic drive device, the valve body electromagnetic drive device is disclosed in, for example, JP-A-8-1.
No. 89315, the first and second electromagnetic coils are provided in the axial direction of the valve body, and the second electromagnetic coil is provided by hydraulic pressure.
There is known an electromagnetic coil in which a lift amount of a valve body is changed by displacing an electromagnetic coil in a valve axis direction.

[0004]

However, in the case where the electromagnetic coil is displaced as in the above-mentioned publication, it is necessary to move a relatively large iron core around which the electromagnetic coil is wound. The device configuration for that purpose becomes large and the structure becomes complicated. As a result, the valve body electromagnetic drive device itself becomes large, and the balance with the engine is reduced. In addition, since the iron core must be moved, responsiveness is reduced.

[0005] An object of the present invention is to solve such a problem.

[0006]

In order to achieve the above object, the present invention takes the following measures. That is, the electromagnetic drive device for a valve body of an internal combustion engine according to the present invention causes an electromagnetic force generated when a voltage is applied to an electromagnetic coil wound around an iron core to act on a mover located in a space in the iron core, An electromagnetic drive device for a valve body of an internal combustion engine that drives a valve body of the internal combustion engine by a drive shaft that is linked to a mover,
The mover is characterized in that its thickness can be changed with respect to the inner dimension of the space in the iron core.

With such a configuration, the distance to the iron core can be changed by changing the thickness of the mover. Therefore, when the electromagnetic coil is energized, the distance over which the mover is attracted changes, and the movable range of the drive shaft increases or decreases. By increasing or decreasing the movable range of the movable shaft, it becomes possible to change the lift amount of the valve body of the internal combustion engine driven by the drive shaft. As described above, since the thickness of the mover is changed, it is possible to reduce the size of the entire device as compared with a case where the iron core is displaced, and to improve the responsiveness of changing the lift amount of the valve element. Can be improved.

As a specific configuration for changing the thickness of the mover, a mover is fixed to a drive shaft by a first mover body;
A second movable member movably attached to the drive shaft, biasing means for biasing the second movable member in a direction away from the first movable member, and a first movable member of the second movable member Is provided on the surface facing away from the iron core and facing the iron core.
A fluid chamber for storing a working fluid that presses the mover body against the urging force of the urging means, wherein at least a part of the fluid chamber is provided between the iron core and a bearing portion of the drive shaft facing the fluid chamber. Provided with a concave portion capable of accommodating the same.

As described above, the fluid chamber is provided on the surface of the second mover facing the iron core, and the recess capable of accommodating at least a part of the fluid chamber is provided between the bearing portion of the drive shaft and the iron core. Therefore, when the mover is sucked into the iron core, a part of the fluid chamber is accommodated in the recess. For this reason, the movable range of the mover can be set large, and it is not necessary to increase the distance between the iron core and the second mover in order to secure a necessary lift amount of the valve body, and the device itself can be downsized. Becomes possible.

[0010]

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

First, a first embodiment will be described with reference to FIGS. An electromagnetic drive device for a valve body, that is, an electromagnetic actuator 100 shown in FIGS. 1 and 2 drives an intake valve or an exhaust valve (not shown) which is a valve body of an engine for an automobile as an internal combustion engine, and is attached to a cylinder head. is there. The electromagnetic actuator 100 includes an iron core 1 including an upper first core member 11 and a lower second core member 12, two electromagnetic coils CL wound around the iron core 1, A drive shaft DS that reciprocates in a space inside the iron core 1 arranged in pairs in the directions, a first mover body P1 that constitutes a mover (armature) P fixed to the drive shaft DS, and a mover P and a second movable element P2 which is slidably mounted on the drive shaft DS.
A coil spring CS that urges the drive shaft DS in a direction in which the intake valve or the exhaust valve opens, and a support member B that forms a bearing portion that supports the drive shaft DS via the cylindrical member S.
And a screw member AB for adjusting the urging force of the coil spring CS. The support member B and the tubular member S have the same height, and are lower than the height of the lower core 1, that is, the second iron core member 12, in the vicinity of the drive shaft DS. For this reason, the recess 2 is formed by the iron core 1, the support member B, and the cylindrical member S.

When no voltage is applied to each of the electromagnetic coils CL, the electromagnetic actuator 100 is attached to an intake valve or the like and urges the intake valve or the like in a fully closed direction without an electromagnetic force acting on the mover P. The biasing force of the valve body coil spring and the biasing force of the coil spring CS are balanced, and the movable element is located at the center of the movable space 13 formed by the first iron core member 11 and the second iron core member 12 constituting the iron core 1. P is stationary. In this state, the intake valve and the like are opened at an intermediate position between the fully closed state and the fully opened state. When a voltage is applied to the upper electromagnetic coil CL, the intake valve and the like resist the urging force of the coil spring CS and the valve body coil The mover P is pulled upward by the spring, the drive shaft DS moves upward, and the intake valve and the like are fully closed. On the other hand, when the upper electromagnetic coil CL is turned off and the lower electromagnetic coil CL is energized, the coil spring CS
The mover P is pulled down against the urging force of the valve coil spring VS, and the drive shaft DS pushes down the intake valve and the like to open it.

In such an electromagnetic actuator 1, the mover P includes a first mover P1 and a second mover P2.
Are urged in a direction away from each other by a spring US serving as urging means. That is, the second movable element P2 is biased downward with respect to the first movable element P1 fixed to the upper end side of the drive shaft DS. Second mover body P
The second movable element P2 is pressed against the urging force of the spring US by hydraulic pressure, which is a fluid pressure, on the surface facing the first movable element P1 and facing the iron core 1, that is, the lower surface of the second movable element P2. A fluid chamber, ie, an oil chamber OC, for storing a working oil, which is a working fluid pressed against, is provided.

The oil chamber OC is provided with a concave portion OC1 provided on the lower surface of the second movable element body P2, and is mounted so as to fit into the concave portion OC1 so that hydraulic oil can be stored by the concave portion OC1. Dish-shaped bottom plate member O that forms a space and closes
And C2. When the hydraulic pressure of the working oil in the oil chamber OC is minimum, the bottom plate member OC2
2 is set to be flush with the lower surface. On the other hand, when the hydraulic pressure reaches the maximum, the second movable element body P2 moves relatively upward with respect to the bottom plate member OC2, so that the bottom plate member OC2 moves.
2 is in a state of protruding from the lower surface of the second mover body P2.
The amount of protrusion of the bottom plate member OC2 when the hydraulic pressure is maximized. In other words, the amount of upward movement of the second movable element P2 is set according to the required valve element lift. The protruding bottom plate member OC2 is housed in a concave portion 2 formed by the iron core 1, the support member B, and the cylindrical member S. Hydraulic oil is supplied to the oil chamber OC via a hydraulic oil passage S1 provided in the cylinder member S and a hydraulic oil passage DS1 provided in the drive shaft DS. The bottom plate member OC2 is prevented from moving when the oil pressure in the oil chamber OC increases due to the stopper SP fixed to the drive shaft DS.

The thickness T of the mover P includes a thickness T1 of the first mover body P1, a gap thickness (distance) T3 of a gap between the first mover body P1 and the second mover body P2, 2 mover body P2
Is the distance from the upper surface of the first movable element P1 to the lower surface of the second movable element P2. When the hydraulic pressure of the hydraulic oil is fixed at a minimum, the thickness T of the movable element P
Is urged downward so that the second movable element P2 is
1, the gap between the first mover body P1 and the second mover body P2 is maximized.
Has the maximum thickness. In this case, the thickness T of the mover P is, for example, about １ ／ of the height of the movable space 13.

On the other hand, when the hydraulic pressure of the hydraulic oil exceeds the urging force of the spring US, the thickness T3 of the movable element P decreases because the gap thickness T3 becomes shorter in accordance with the hydraulic pressure. When the hydraulic pressure reaches the set maximum value, the second movable element P2 is moved to the first position against the urging force of the spring US.
Since it is pushed up until it comes into contact with the mover body P1, the gap thickness T3 becomes substantially 0, and the thickness T of the mover P is substantially equal to the sum of the thicknesses T1 and T2 of the first mover body P1 and the second mover body P2. Become equal.

The hydraulic oil is such that the movement into and out of the oil chamber OC is stopped (locked) while the thickness of the mover P is adjusted, and the state in which the hydraulic pressure does not change is maintained. By restricting the movement of the hydraulic oil in this way, the first mover body P1 and the second mover body P2 are integrally formed, that is, when one mover body is sucked, the other mover body is moved. It avoids remaining at the position before suction. That is, when the upper electromagnetic coil CL is energized, the first movable element body P1 is attracted, but the hydraulic pressure of the working oil is maintained unchanged, so that the hydraulic pressure in the oil chamber is reduced and the first movable element is reduced. The distance between the body P1 and the second mover body P2 does not increase, and the second mover body P2 also moves upward while maintaining the gap between the first mover body P1 and the second mover body P2. When the lower electromagnetic coil CL is energized, the second movable element is attracted to the lower electromagnetic coil CL. Similarly, the first movable element body P1 and the second movable element
The distance from the mover body P2 does not increase.

In such a configuration, the valve lift of the intake valve and the like is adjusted by changing the thickness T of the mover P with respect to the inner dimension of the movable space 13 to change the movable range of the mover P. And do it. That is, when the hydraulic pressure of the hydraulic oil is fixed at a minimum, the thickness T of the mover P is equal to the thicknesses T1 and T2 of the first mover body P1 and the second mover body P2.
And the gap thickness T3. The gap thickness is maximum because T3 is the maximum value, and the effective distance in the movable space 13 is reduced by increasing the thickness T of the mover P, that is, the second movable Child body P2 and lower second core member 1
2, the valve lift of the intake valve and the like is minimized.

On the other hand, when the oil pressure of the working oil in the oil chamber OC becomes higher than the urging force of the spring US, the second movable element P2 is pushed up by the oil pressure. Thereby, the distance from the upper surface of the first mover body P1 to the lower surface of the second mover body P2 is reduced, and the thickness T of the mover P is reduced. Therefore, the movable range of the mover P in the movable space 13 is expanded by a value thinner than the case where the thickness T of the mover P is the maximum. For this reason, the distance between the second armature P2 and the second iron core member 12 becomes longer, and the valve lift of the intake valve and the like increases.
Since the hydraulic pressure of the hydraulic oil can be changed continuously, the thickness T of the mover P can also be changed and set steplessly.

Therefore, the intake valve and the like can be controlled with various valve lifts. Furthermore, when the hydraulic pressure of the hydraulic oil is maximized, the second mover body P2 comes into close contact with the first mover body P1, so that the thickness T of the mover P is equal to the first mover body P1 and the second mover body. The thickness becomes substantially the total value of P2 and the valve lift of the intake valve and the like can be maximized. As described above, the valve lift of the intake valve or the like can be adjusted only by changing the position of the second movable element P2 having a small weight. This makes it easy to control the hydraulic oil and quickly adjusts the valve lift to a desired value. Further, the valve lift can be changed by changing the thickness T of the mover P, so that the device itself can be prevented from becoming large-scale and can be manufactured compactly.

Next, a second embodiment of the present invention will be described with reference to FIG. In the second embodiment and a third embodiment described later, the mover P
The basic structure and operation of the electromagnetic actuator such as the iron core 1, the electromagnetic coil CL, the support member B, and the drive shaft DS excluding the lower coil spring LUS for urging the mover P from below are described in the first embodiment. This is the same as the embodiment described above, and the description thereof is omitted.

In the second embodiment, the mover 2P
Are two dish-shaped first movable elements 2P having an L-shaped cross section.
1 and the second mover body 2P2. Specifically, the mover 2P is provided with a first mover body 2P1 located on the upper side and fixed to the drive shaft, and an oil-tight and first mover body 2P1 inside the first mover body 2P1. And a second mover body 2P2 slidably attached to the drive shaft DS. The first mover body 2P1 and the second mover body 2P2 are combined to store hydraulic oil inside the second mover body 2P2. An oil chamber 2OC is formed. The second mover body 2P2 is urged upward by the lower coil spring LUS, and is restricted from moving downward by the stopper 2SP.

In this embodiment, the thickness of the mover 2P is maximum when the hydraulic pressure of the hydraulic oil is maximum and is minimum when the hydraulic pressure is minimum, and the difference between the maximum thickness and the minimum thickness is as follows. , According to the required valve lift. That is, when the hydraulic pressure becomes maximum, the second movable element 2 is pressed against the urging force of the lower coil spring LUS.
P2 descends and contacts the stopper 2SP to maintain that position. In this case, the hydraulic oil is locked in the same manner as in the first embodiment, and when the upper electromagnetic coil CL is energized, together with the first movable element 2P1 while maintaining the thickness. Is going to rise. On the other hand, when the hydraulic pressure becomes minimum, the second movable element 2P2
Is biased by the lower coil spring LUS, and the first
The distance from the mover 2P1 is reduced until the vertical wall portion contacts the first mover 2P1. Further, by adjusting the hydraulic pressure with respect to the urging force of the lower coil spring LUS, the first movable member 2P1 and the second movable member 2P are adjusted.
It is possible to steplessly change the distance between the movable member 2 and the thickness of the mover 2P.

As described above, by forming the oil chamber 2OC of the working oil by the first mover body 2P1 and the second mover body 2P2, a separate component is not required for forming the oil chamber 2OC. The number of parts of the mover P can be reduced, and the structure can be simplified.

Next, a third embodiment of the present invention will be described with reference to FIG.

In the third embodiment, the oil chamber OC of the working oil described in the first embodiment is provided between the first movable element 3P1 and the second movable element 3P2, that is, the movable element 3P.
It is the structure arranged inside. That is, the first mover body 3P1 is fixed to the upper end of the drive shaft DS, and the second mover body 3P2 is slidably attached to the drive shaft DS below the first mover body 3P1, The oil chamber 3OC is formed by a recess 3P2a provided near the drive shaft DS on the upper surface of the second mover body 3P2, and a ceiling member 3P2b which is oil-tight with respect to the recess 3P2a and is fixed to the drive shaft DS. It is formed. The downward movement of the second movable element 3P2 is restricted by the stopper 3SP fixed to the drive shaft DS, and the mounting position of the stopper 3SP is set according to the required valve element lift amount. It is.

In such a configuration, when the hydraulic pressure of the operating oil in the oil chamber 3OC is minimum, the lower coil spring L
The US urges the second mover body 3P2 upward, and the second mover body 3P2 is stopped in a state in which the upward movement is prevented by the vertical wall portion of the ceiling member 3P2b. When the hydraulic pressure of the operating oil in the oil chamber 3OC is increased from this state, the second mover body 3P2 moves downward according to the hydraulic pressure, and the thickness of the mover 3P increases. When the thickness of the mover 3P increases in this manner, the movable range of the mover 3P between the first and second core members 11 and 12 decreases, so that the valve body lift amount when the hydraulic pressure is minimum is reduced. As a result, the valve body lift decreases. As described above, by changing the thickness of the mover 3P according to the oil pressure, the valve element lift can be adjusted. Moreover, as in the above embodiments, the thickness of the mover 3P is changed, so that the device itself can be miniaturized and the desired valve body lift can be quickly adjusted to a desired value. .

The present invention is not limited to the embodiment described above.

In addition, the configuration of each section is not limited to the illustrated example, and various modifications can be made without departing from the spirit of the present invention.

[0030]

As described above, according to the present invention, the distance to the iron core can be changed by changing the thickness of the mover, so that when the electromagnetic coil is energized, the mover moves. The suction distance changes, and the movable range of the drive shaft can be increased or decreased. Therefore, the lift amount of the valve body of the internal combustion engine driven by the drive shaft can be changed. As described above, since the thickness of the mover is changed, it is possible to reduce the size of the entire device as compared with a case where the iron core is displaced, and to improve the responsiveness of changing the lift amount of the valve element. Can be improved.

Further, a first movable member is fixed to a drive shaft.
A movable element, a second movable element movably attached to the drive shaft, an urging means for urging the second movable element in a direction away from the first movable element, A fluid chamber that is provided on a surface facing the first armature and facing the iron core and that stores a working fluid that presses the second armature against the urging force of the urging means by fluid pressure; If a recess capable of accommodating at least a part of the fluid chamber is provided between the bearing portion of the drive shaft facing the fluid chamber and the iron core, the fluid chamber is provided when the mover is sucked into the iron core. Is accommodated in the recess, so that the movable range of the mover can be set large, and it is necessary to increase the distance between the iron core and the second mover in order to secure a necessary lift amount of the valve element. Gone
The device itself can be reduced in size.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a first embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of the embodiment.

FIG. 3 is a diagram corresponding to FIG. 2 of a second embodiment of the present invention.

FIG. 4 is a diagram corresponding to FIG. 2 of a third embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Iron core 2 ... Concave part CL ... Electromagnetic coil DS ... Drive shaft 13 ... Internal space P ... Mover P1 ... 1st mover P2 ... 2nd mover OC ... Oil chamber US ... Spring

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G018 AB09 AB11 AB16 BA38 CA16 CA19 DA41 DA43 DA51 DA52 DA54 DA56 EA22 FA01 FA06 FA07 FA11 GA03 GA14 3H106 DA07 DA25 DB02 DB12 DB26 DB32 DC02 DD03 EE34 FA08 GA15 KK17

Claims (2)

[Claims] An electromagnetic force generated when a voltage is applied to an electromagnetic coil wound around an iron core acts on a mover located in a space within the iron core, and a valve of the internal combustion engine is driven by a drive shaft interlocked with the mover. An electromagnetic drive device for a valve body of an internal combustion engine that drives a body, wherein the mover is configured to be able to change its thickness with respect to an inner dimension of a space in an iron core. Electromagnetic drive for body. A movable member fixed to the drive shaft; a second movable member movably mounted on the drive shaft; and a second movable member separated from the first movable member. A biasing means for biasing the second movable element body in a direction facing the first movable element body and facing the iron core, the second movable element body being biased by a fluid pressure. A fluid chamber for storing a working fluid pressed against the force, and a recess capable of accommodating at least a part of the fluid chamber is provided between a bearing portion of the drive shaft facing the fluid chamber and the iron core. The electromagnetic drive device for a valve body of an internal combustion engine according to claim 1, wherein: