JP2001355417A - Internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the interference of a movable body and a casing or the like in accompany with the rotation of the movable body to prevent the generation of the noise, and the fracture of the movable body, the casing or the like by inhibiting the unnecessary rotation of the movable body in a solenoid driving- type valve system. SOLUTION: In this internal combustion engine having a solenoid driving valve comprising a shaft member 310 holding an armature displaceable by electromagnetic force and transmitting the electromagnetic force to a valve element, and a bearing part (upper bush) 319 for axially slidably supporting the shaft member 310, a part slidably kept into contact with at least the bearing part 319 of the shaft member 310 has the axial cross sectional shape where a distance between one point on an outer periphery and a shaft center is different from a distance between another point on the outer periphery and the shaft center. The shaft member 310 is brought into contact with the bearing part 319 at least at one point having the distance from the shaft center shorter than the maximum distance to the outer periphery, and supported by the bearing part 319 to inhibit the continuous rotation.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine mounted on an automobile or the like, and more particularly, to an internal combustion engine provided with an electromagnetically driven valve operating mechanism for opening and closing an intake valve using electromagnetic force.

[0002]

2. Description of the Related Art In recent years, in internal combustion engines mounted on automobiles and the like, mechanical loss caused by opening and closing of intake and exhaust valves has been prevented.
For the purpose of preventing intake pumping loss, improving net thermal efficiency, and the like, the development of an electromagnetically driven valve mechanism capable of arbitrarily changing the opening / closing timing of an intake valve and an exhaust valve has been promoted.

The electromagnetically driven valve mechanism includes, for example, an armature made of a magnetic material and moving forward and backward in conjunction with an intake / exhaust valve, and an electromagnetic force for displacing the armature in a valve closing direction when an excitation current is applied. A valve-closing electromagnet that is generated, a valve-opening electromagnet that generates an electromagnetic force that displaces the armature in the valve-opening direction when an exciting current is applied, and a valve-opening-side bias that urges the armature toward the valve-opening side. A spring, a valve-closing spring for biasing the armature to the valve-closing side, and the above-described armature, valve-closing electromagnet, valve-opening electromagnet, valve-opening-side biasing spring, and valve-closing-side biasing spring are housed. A device including a housing has been proposed.

According to such an electromagnetically driven valve train,
Since it is not necessary to open and close the intake and exhaust valves using the rotational force of the engine output shaft (crankshaft) as in a conventional valve operating mechanism, mechanical loss due to driving of the intake and exhaust valves is prevented.

Further, according to the above-described electromagnetically driven valve operating mechanism, the intake and exhaust valves can be opened and closed independently of the rotation of the engine output shaft. There are various advantages such as a high degree of freedom when controlling

[0006]

In the above-described electromagnetically driven valve operating mechanism, when the valve-opening-side urging spring and the valve-closing-side urging spring expand and contract, these valve-opening-side urging springs and Since both ends of the valve-closing-side biasing spring rotate relatively, when the valve-opening-side biasing spring and the valve-closing-side biasing spring expand and contract with the displacement of the armature, the valve-opening-side biasing spring and the valve-closing spring close. Rotational torque resulting from the relative rotation of both ends of the side biasing spring acts on the armature, and the armature may rotate.

The armature includes a movable member made of a plate-shaped magnetic material and a shaft member fixed to the movable member so as to penetrate the movable member in the axial direction. When the distance to the outer periphery of the mover is not constant (non-perfect circle, for example, a square), the corner 4 of the mover 400 is rotated by rotation of the armature as shown in FIG.
01 may interfere with the inner wall surface of the housing 402 containing the armature, causing noise and damaging the mover or the housing. Therefore, it is necessary to prevent rotation of the armature so that such interference does not occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and in an electromagnetically driven valve operating mechanism that opens and closes intake and exhaust valves of an internal combustion engine using electromagnetic force, a movable element is unnecessary. An object of the present invention is to prevent rotation of the mover from causing interference between the mover and the housing or the like due to rotation of the mover, thereby preventing generation of noise or damage to the mover or the housing.

[0009]

The present invention employs the following means to solve the above-mentioned problems. That is, the internal combustion engine according to the present invention includes an axis member that holds an armature that is displaced by electromagnetic force, transmits an electromagnetic force to a valve body, and a bearing portion that supports the axis member slidably in the axial direction. An internal combustion engine having an electromagnetically driven valve that drives the valve body using an electromagnetic force, wherein at least a portion of the shaft member that slidably contacts a bearing portion has an axial cross-sectional shape that extends from an axis to an outer periphery. The distance to the upper point and the distance from the axis to another point on the outer circumference are formed to be different from each other, and the shaft member is located at a position where the distance from the axis is smaller than the maximum distance to the outer circumference. At least one point on the outer periphery of the above is contacted with the bearing portion and is supported by the bearing portion so as not to allow continuous rotation.

Here, the shaft section shape of the shaft member may be any shape other than a perfect circle, since the shaft member may be supported by the bearing portion so as not to rotate while being allowed to slide in the axial direction. . For example, the shape may be a polygon having a protrusion on the outer periphery, such as a circle, a triangle, a square, a hexagon, or an ellipse.

On the other hand, the bearing portion is located at a position other than the point at which the distance from the axis of the shaft member to the outer periphery is maximized.
It is sufficient that at least one point is in contact with and supports the outer periphery of the shaft member. That is, the shape of the bearing portion supporting the shaft member is not particularly limited as long as it can support the shaft member so as not to allow continuous rotation.
Here, the term "supported so as not to allow continuous rotation" includes not only one that does not allow rotation at all, but also one that allows rotation within a certain range, but in order to effectively prevent damage and noise due to rotation of the armature. It is desirable that the shaft member is supported by the bearing portion so that the rotation of the shaft member is hardly allowed. Therefore, the bearing portion that supports the shaft member slidably in the axial direction suppresses the rotation of the shaft member and has a shape substantially the same as the shaft cross-sectional shape of the shaft member in order to reliably guide the shaft member only in the axial direction. It is preferred that

As described above, according to the present invention, at least a portion of the shaft member holding the armature that is slidably in contact with the bearing portion has a shaft cross-sectional shape that is a distance from the axis to one point on the outer periphery;
The distance from the axis to another point on the outer periphery is different from each other, and the shaft member is in contact with at least one point on the outer periphery at a position where the distance from the axis is smaller than the maximum distance to the outer periphery. As described above, since the bearing is supported by the bearing, a rotational resistance is generated in the bearing and the rotation of the shaft member is suppressed. Therefore, it is possible to prevent the armature fixed to the shaft member from continuously rotating and its outer peripheral portion from colliding with the surrounding structure.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A specific embodiment of an internal combustion engine having an electromagnetically driven valve according to the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing a schematic configuration of an internal combustion engine and an intake / exhaust system thereof according to the present embodiment. The internal combustion engine 1 shown in FIGS. 1 and 2 has four cylinders 21.
It is a stroke cycle water-cooled gasoline engine.

The internal combustion engine 1 includes a cylinder block 1b in which four cylinders 21 and a cooling water passage 1c are formed, and a cylinder head 1 fixed on an upper portion of the cylinder block 1b.
a.

A crankshaft 23 as an engine output shaft is rotatably supported by the cylinder block 1b. The crankshaft 23 is connected to a piston 22 slidably mounted in each cylinder 21 via a connecting rod 19. Connected.

At the end of the crankshaft 23, a crank position sensor 51 having a timing rotor 51a and an electromagnetic pickup 51b is provided. A water temperature sensor 52 that outputs an electric signal corresponding to the temperature of the cooling water flowing in the cooling water passage 1c is attached to the cylinder block 1b.

Above the piston 22 of each cylinder 21, a combustion chamber 24 surrounded by the top surface of the piston 22 and the wall surface of the cylinder head 1a is formed. The cylinder head 1
a includes spark plugs 25 facing the combustion chamber 24 of each cylinder 21.
The ignition plug 25 is connected to an igniter 25a for applying a drive current to the ignition plug 25.

In the cylinder head 1a, each cylinder 2
Two open ends of the intake port 26 and two open ends of the exhaust port 27 are formed at a portion facing one combustion chamber 24. And the cylinder head 1
In a, an intake valve 28 for opening and closing each open end of the intake port 26 and an exhaust valve 29 for opening and closing each open end of the exhaust port 27 are provided to be able to move forward and backward.

An electromagnetic drive mechanism 30 for driving the intake valve 28 forward and backward by using an electromagnetic force generated when an excitation current is applied to the cylinder head 1a (hereinafter referred to as an intake-side electromagnetic drive mechanism 30). Are provided in the same number as the intake valves 28. Each intake-side electromagnetic drive mechanism 30 has a drive circuit 30 a for applying an exciting current to the intake-side electromagnetic drive 30.
(Hereinafter, referred to as an intake-side drive circuit 30a).

An electromagnetic drive mechanism 31 for driving the exhaust valve 29 forward and backward by using an electromagnetic force generated when an excitation current is applied to the cylinder head 1a (hereinafter referred to as an exhaust-side electromagnetic drive mechanism 31). Are provided in the same number as the exhaust valves 29. Each exhaust-side electromagnetic drive mechanism 31 has a drive circuit 31 for applying an exciting current to the exhaust-side electromagnetic drive mechanism 31.
a (hereinafter, referred to as an exhaust-side drive circuit 31a) is electrically connected.

The cylinder head 1a of the internal combustion engine 1 has 4
An intake branch pipe 33 composed of two branch pipes is connected, and each branch pipe of the intake branch pipe 33 communicates with the intake port 26 of each cylinder 21.

A fuel injection valve 32 is attached to the cylinder head 1a in the vicinity of the connection portion with the intake branch pipe 33 so that the injection hole faces the intake port 26. The intake branch pipe 33 is connected to a surge tank 34 for suppressing pulsation of intake air. An intake pipe 35 is connected to the surge tank 34. The intake pipe 35 is provided with an air cleaner box 3 for removing dust and dirt during intake.
6 is connected.

An air flow meter 44 for outputting an electric signal corresponding to the mass of air flowing through the intake pipe 35 (mass of intake air) is attached to the intake pipe 35.
A throttle valve 39 for adjusting the flow rate of intake air flowing through the intake pipe 35 is provided at a position downstream of the air flow meter 44 in the intake pipe 35.

The throttle valve 39 is provided with a throttle actuator 40 for driving the opening and closing of the throttle valve 39 in accordance with the magnitude of the applied electric power.
And a throttle position sensor 41 for outputting an electric signal corresponding to the opening of the throttle valve 39.

The throttle valve 39 is rotatable independently of the throttle valve 39, and the accelerator pedal 4
An accelerator lever (not shown) that rotates in conjunction with 2 is attached to the accelerator lever, and an accelerator position sensor 43 that outputs an electric signal corresponding to the amount of rotation of the accelerator lever is attached to the accelerator lever.

On the other hand, the cylinder head 1 of the internal combustion engine 1
An exhaust branch pipe 45 formed so that four branch pipes merge into one collecting pipe immediately downstream of the internal combustion engine 1 is connected to a, and each branch pipe of the exhaust branch pipe 45 is connected to each cylinder 21. The exhaust port 27 communicates with the exhaust port 27.

The exhaust branch pipe 45 is connected to an exhaust pipe 47 via an exhaust purification catalyst 46, and the exhaust pipe 47 is connected downstream to a muffler (not shown). The exhaust branch pipe 4
5 is provided with an air-fuel ratio sensor 48 that outputs an electric signal corresponding to the air-fuel ratio of the exhaust flowing in the exhaust branch pipe 45, in other words, the exhaust flowing into the exhaust purification catalyst 46.

The internal combustion engine 1 configured as described above is provided with an electronic control unit (ECU) 20 for controlling the operating state of the internal combustion engine 1.

The ECU 20 includes a throttle position sensor 41, an accelerator position sensor 43, an air flow meter 44, an air-fuel ratio sensor 48, a crank position sensor 51, a water temperature sensor 52, and a valve lift sensor 3.
Various sensors such as 17 are connected via electric wiring, and output signals of each sensor are input to the ECU 20.

The ECU 20 includes an igniter 25a,
The intake-side drive circuit 30a, the exhaust-side drive circuit 31a, the fuel injection valve 32, the throttle actuator 40, and the like are connected via electric wiring, and the ECU 20 sets the igniter 25
a, the intake side drive circuit 30a, the exhaust side drive circuit 31a, the fuel injection valve 32, or the throttle actuator 40
Can be controlled.

Next, a specific configuration of the intake-side electromagnetic drive mechanism 30 according to the present embodiment will be described. FIG. 3 is a cross-sectional view illustrating the configuration of the intake-side electromagnetic drive mechanism 30. In FIG. 3, the cylinder head 1a of the internal combustion engine 1 includes a lower head 10 fixed to the upper surface of the cylinder block 1b, and an upper head 11 provided on the lower head 10.

In the lower head 10, two intake ports 26 are formed for each cylinder 21. At the open end of each intake port 26 on the combustion chamber 24 side, a valve body 28a of an intake valve 28 is seated. A valve seat 12 is provided.

The lower head 10 is provided with each intake port 2
A penetrating part having a circular cross section is formed from the inner wall surface of 6 to the upper surface of the lower head 10, and a cylindrical valve guide 13 is inserted into the penetrating part. A valve shaft 28b of the intake valve 28 penetrates through an inner hole of the valve guide 13, and the valve shaft 2
8b is slidable in the axial direction.

In the upper head 11, a core mounting hole 14 having a rectangular cross section into which a first core 301 and a second core 302 having a rectangular parallelepiped shape are fitted is provided at a position where the axis of the valve guide 13 is the same as that of the valve guide 13. . The lower part 14b of the core mounting hole 14 is formed larger in diameter than the upper part 14a. Hereinafter, a lower portion 14b of the core mounting hole 14
Is referred to as a large diameter portion 14b, and the upper portion 14 of the core mounting hole 14 is
a is referred to as a small diameter portion 14a.

In the small-diameter portion 14a, a first core 301 and a second core 302 made of a soft magnetic material are provided with a predetermined gap 303.
Are inserted in series in the axial direction. These first
A flange 301a and a flange 302a are formed at the upper end of the core 301 and the lower end of the second core 302, respectively, and the first core 301 is inserted into the core mounting hole 14 from above and the second core 302 is inserted from below. The first core 301 and the second core 302 are positioned by the flange 301a and the flange 302a abutting on the edge of the core mounting hole 14, so that the gap 303 is maintained at a predetermined distance. I have.

On the upper part of the first core 301, an upper plate 318 larger in diameter than the large diameter part 14b of the core mounting hole 14 is provided.
Is disposed on the upper plate 318, and an upper cap 30 having a flange 305a having substantially the same width as the upper plate 318 formed at the lower end of the cylindrical body.
5 are arranged.

The upper cap 305 and the upper plate 318 are connected to the flange 3 of the upper cap 305.
It is fixed to the upper surface of the upper head 11 by a bolt 304 that penetrates from the upper surface of the upper head 05a to the inside of the upper head 11 via the upper plate 318.

In this case, the lower end of the upper cap 305 including the flange portion 305a contacts the upper surface of the upper plate 318, and the lower surface of the upper plate 318
The core 301 is fixed to the upper head 11 while being in contact with the peripheral edge of the upper surface. As a result, the first core 30
1 is fixed to the upper head 11.

A lower plate 307 having substantially the same width as the large-diameter portion 14b of the core mounting hole 14 is provided below the second core 302.
Is provided. The lower plate 307 is fixed to the small-diameter portion 14 a and the large-diameter portion 14 b by bolts 306 penetrating from the lower surface of the lower plate 307 to the upper head 11.
Are fixed to the downward step surface in the step portion. In this case, the lower plate 307 is fixed in a state in which the lower plate 307 is in contact with the lower peripheral edge of the second core 302, and as a result,
The second core 302 is fixed to the upper head 11.

A groove formed on the surface of the first core 301 on the side of the gap 303 holds a first electromagnetic coil 308, and is formed on a surface of the second core 302 on the side of the gap 303. The second electromagnetic coil 309 is held in the groove. At this time, the first electromagnetic coil 308 and the second electromagnetic coil 309 are arranged at positions facing each other via the gap 303. The first and second electromagnetic coils 308 and 309 are connected to the intake side drive circuit 30 described above.
a.

The first core 301 and the first electromagnetic coil 308 constitute an electromagnet of the electromagnetic drive mechanism 30, and the second core 302 and the second electromagnetic coil 3
09 also constitutes an electromagnet.

In the gap 303, an armature 311 made of a soft magnetic material and having a rectangular plate shape is arranged. In the armature 311, a shaft member 310 made of a non-magnetic material extends vertically from the center of the armature 311 and penetrates the first core 301 and the second core 302 as shown in FIG. 4. Fixed. The shaft member 310 detects the displacement of the armature 311 by using the valve body 28a.
To form a so-called armature shaft.

The upper end of the shaft member 310 has the first shape.
The lower end is formed so as to penetrate the second core 302 and reach the inside of the large-diameter portion 14 b while penetrating the core 301 and reaching the inside of the upper cap 305.

Correspondingly, the outlets of the through-passages 321 on the upper end surface of the first core 301 and the lower end surface of the second core 302 have the same diameter as the outer diameter of the shaft member 310. An annular upper bush 319 having an inner diameter and a lower bush 320 are provided.
The shaft member 310 is slidably supported in the axial direction by the and the lower bush 320. That is, the upper bush 319 and the lower bush 320 constitute a bearing that supports the shaft member 310.

On the other hand, the outer peripheral surface of the shaft member 310, which is in contact with the upper bush 319 and the lower bush 320, has a groove 310 shown in FIGS.
a is formed. The groove 310a is
Are provided at positions facing each other on the outer peripheral surface of the
The groove 310b opposite to 10a is disposed at an angle of 180 °. As shown in FIG. 6, pins 322 are press-fitted into these grooves 310b, and the pins 322 have a convex shape including a rectangular main body 322a and a protrusion 322b protruding from one side thereof. In this case, the main body 3 of the pin 322
The entirety of the protrusion 22a is substantially housed in the groove 310a.
22b protrudes outward from the groove 310a.
Therefore, on the outer peripheral surface of the shaft member 310, the protrusions 322b are formed at two symmetrical positions in the vertical and horizontal directions.

As described above, the shaft member 310 is inserted through the first core 301 and the second core 302, and the shaft member 310
To the upper bush 319 and the lower bush 320, respectively.
Support. Each of the upper bush 319 and the lower bush 320 has a cutout groove 323 into which the protrusion 322b is fitted. Also, the shaft member 310
As shown in FIG. 3, the upper bush 319 and the lower bush 320 are inserted into each other, and the protrusion 322a is fitted into the cutout groove 323 with respect to the upper bush 319 (same for the lower bush 320) as shown in FIG. Although this shaft member 310 is guided slidably in the axial direction,
Rotation is blocked.

The cross-sectional shape of the shaft member 310 and the shapes of the upper bush 319 and the lower bush 320 that support the shaft member 310 are, for example, shown in FIGS.
It can be a polygon or an ellipse as shown in (c) or (d).

Further, as shown in FIG. 10, if the cross section of the shaft member 310 is quadrangular, for example, the upper bush 319
By installing at least one of the and the lower bush 320 so as to be in contact with one side thereof, the rotation of the shaft member 310 is prevented.

When the shaft section of the shaft member 310 has an elliptical shape other than a polygon or a circular shape having a projection, two or more points on the outer periphery are effectively used to effectively prevent the rotation.
It is preferable to support at least one of the lower bush 9 and the lower bush 320.

Next, a disc-shaped upper retainer 312 is joined to the upper end of the shaft member 310 extending into the upper cap 305, and the upper cap 3
Adjust bolts 313 are screwed into upper openings of the bolts 05 and 05.
13, an upper spring 314 is interposed. The upper cap 3 is provided on the contact surface between the adjusting bolt 313 and the upper spring 314.
Spring seat 3 having an outer diameter substantially the same as the inner diameter of 05
15 are interposed.

The shaft member 31 extending into the large diameter portion 14b
The lower end of 0 is in contact with the upper end of the valve shaft 28b of the intake valve 28. A disc-shaped lower retainer 28c is joined to the outer periphery of the upper end of the valve shaft 28b. A lower spring 316 is interposed between the lower surface of the lower retainer 28c and the upper surface of the lower head 10.

The above-mentioned intake side electromagnetic drive mechanism 30 is provided with a lubrication mechanism to reduce the sliding resistance between the shaft member 310 and the upper bush 318a and the sliding resistance between the shaft member 310 and the lower bush 307a. Have been.

The above-described lubricating mechanism includes an annular upper-side recess 318 a provided on the lower surface of the upper plate 318 at a position facing the upper surface of the upper bush 319.
An annular lower recess 307a provided on the upper surface of the lower plate 307 at a position facing the lower bush 320; and an upper oil passage for guiding lubricating oil discharged from an oil pump (not shown) to the upper recess 318a. 401, a lower oil passage 40 for guiding the lubricating oil discharged from the oil pump to the lower recess 307a.
2, a communication passage 403 for guiding excess lubricating oil supplied to the upper recess 318a to the lower recess 307a;
A return passage 40 for returning the lubricating oil that has dropped from the lower recess 307a through the gap between the shaft member 310 and the lower plate 307 into the large-diameter portion 14b to an oil pan (not shown).
4 is provided.

In the example shown in FIG. 3, the upper oil passage 401 is connected to the upper head 11 by the oil pump.
The lower oil passage 402 is formed so as to reach the upper recess 318a via the flange 301a of the first core 301 and the inside of the upper plate 318, and the lower oil passage 402 is provided from the oil pump to the upper head 11, the second core 302, and the lower. The communication path 403 is formed so as to reach the lower side recess 307 via the inside of the plate, and the upper side recess 318.
a to the lower side recess 307a via the upper plate 318, the flange 301a of the first core 301, the upper head 11, the flange 302a of the second core 302, and the inside of the lower plate 307. , From the large diameter portion 14b to the oil pan via the inside of the lower head 10.

The above-mentioned upper oil passage 401,
The configurations of the lower oil passage 402, the communication passage 403, and the return passage 404 are not limited to the configuration shown in FIG.

In the intake-side electromagnetic drive mechanism 30 configured as described above, when no excitation current is applied to the first electromagnetic coil 308 and the second electromagnetic coil 309 from the intake-side drive circuit 30a, A downward direction from the upper spring 314 to the shaft member 310 (that is, the intake valve 28
(In a direction to open the intake valve 28), and an urging force from the lower spring 316 to the intake valve 28 in an upward direction (that is, a direction in which the intake valve 28 is closed) acts. The shaft member 310 and the intake valve 28 are held in a state in which they are elastically supported at a predetermined position while being in contact with each other, that is, a so-called neutral state.

The biasing force of the upper spring 314 and the lower spring 316 is set so that the neutral position of the armature 311 is located at an intermediate position between the first core 301 and the second core 302 in the gap 303. If the neutral position of the armature 311 is deviated from the above-described intermediate position due to an initial tolerance or a secular change of a component, the neutral position of the armature 311 is adjusted by the adjustment bolt 313 so as to match the above-described intermediate position. Has become possible.

The axial length of the shaft member 310 and the valve shaft 28b is determined by the distance between the armature 311 and the gap 303.
When the valve body 28a is located at an intermediate position between the valve-opening-side displacement end and the valve-closing-side displacement end (hereinafter, referred to as a middle-open position), the armature 311 is connected to the first core 301. The valve body 28a is set to be seated on the valve seat 12 when it comes into contact with the valve seat 28.

In the above-described intake-side electromagnetic drive mechanism 30, when the excitation current is applied from the intake-side drive circuit 30a to the first electromagnetic coil 308, the first core 301 and the first electromagnetic coil 308 are connected to each other. Since an electromagnetic force is generated between the armature 311 and the armature 311 in the direction of displacing the armature 311 toward the first core 301, the armature 311 is displaced toward the valve closing side against the urging force of the upper spring 314, and the first
It comes into contact with the core 301. When the armature 311 is in contact with the first core 301, the intake valve 28 retreats by receiving the urging force of the lower spring 316, and retreats.
Is in a state where the valve body 28a is seated on the valve seat 12, that is, a fully closed state.

In the above-described intake-side electromagnetic drive mechanism 30, when an excitation current is applied from the intake-side drive circuit 30a to the second electromagnetic coil 309, the second core 302 and the second electromagnetic coil 309 are connected to each other. Since an electromagnetic force is generated between the armature 311 and the armature 311 in the direction of displacing the armature 311 toward the second core 302, the armature 311 is displaced toward the valve opening side against the urging force of the lower spring 316, It comes into contact with the core 302.

When the armature 311 is in contact with the second core 302, the shaft member 310
The valve shaft 28b is pressed in the valve opening direction against the urging force of No. 6, and the pressing force holds the intake valve 28 in the fully open state.

In the above-described intake side electromagnetic drive mechanism 30, when the intake valve 28 in the fully closed state is opened, first, the intake side drive circuit 30a stops applying the exciting current to the first electromagnetic coil 308.

At this time, since the electromagnetic force for attracting the armature 311 to the first core 301 between the first core 301, the first electromagnetic coil 308, and the shaft member 310 disappears, the armature 311 and the intake valve 28 are connected to the upper spring. 31
In response to the urging force of No. 4, it is displaced in the valve opening direction.

The intake side drive circuit 30a includes an armature 31
When the first electromagnetic coil 3 is displaced to the vicinity of the second core 302 by receiving the urging force of the upper spring 314, the second electromagnetic coil 3
By applying an exciting current to the second coil 302, an electromagnetic force that attracts the armature 311 to the second core 302 is generated between the second core 302, the second electromagnetic coil 309, and the armature 311. Armature 31 by this electromagnetic force
1 is displaced to a position where it comes into contact with the second core 302 (valve opening side displacement end), and as a result, the intake valve 28 is fully opened.

In the above-described intake-side electromagnetic drive mechanism 30, when closing the intake valve 28 in the fully open state, the intake-side drive circuit 30a first stops applying the exciting current to the second electromagnetic coil 309.

At this time, since the electromagnetic force for attracting the armature 311 to the second core 302 between the second core 302, the second electromagnetic coil 309, and the shaft member 310 disappears, the armature 311 and the intake valve 28 are connected to the lower spring. 316
The valve is displaced in the valve closing direction by receiving the urging force.

The intake side drive circuit 30a includes an armature 31
The first core 3 receives the urging force of the lower spring 316
01, the first electromagnetic coil 30
8 by applying an exciting current to the first core 3.
01, the first electromagnetic coil 308, and the armature 311, an electromagnetic force for attracting the armature 311 to the first core 301 is generated. Armature 31 by this electromagnetic force
1 is displaced to a position where it comes into contact with the first core 301 (displacement end on the valve closing side). As a result, the valve body 28a of the intake valve 28 is
Sit on 2.

As described above, the intake side drive circuit 30a alternately applies the exciting current to the first electromagnetic coil 308 and the second electromagnetic coil 309 at a predetermined timing, whereby the armature 311 is displaced to the valve closing side. The valve member 28a moves forward and backward between the end and the valve-opening-side displacement end, and with the operation of the shaft member 310 accompanying this, the valve shaft 28b is driven forward and backward, and at the same time, the valve body 28a is opened and closed.

Therefore, the ECU 20 determines whether the first electromagnetic coil 3
The opening / closing timing of the intake valve 28 can be arbitrarily controlled by controlling the intake side drive circuit 30a to change the application timing of the exciting current to the 08 and the second electromagnetic coil 309.

In the intake electromagnetic drive mechanism 30 according to the present embodiment, the winding directions of the upper spring 314 and the lower spring 316 are opposite to each other.
For example, when the upper spring 314 is formed in a clockwise direction from the upper end to the lower end, the lower spring 316 is formed.
Is formed left-handed from the upper end to the lower end, and when the upper spring 314 is formed left-handed from the upper end to the lower end, the lower spring 316 is formed right-handed from the upper end to the lower end.

Here, when the upper spring 314 contracts, the lower end of the upper spring 314 generates a biasing force to expand along the winding direction. When the upper spring 314 expands, the lower end of the upper spring 314 expands. The lower end generates an urging force that tends to contract in the direction opposite to the winding direction.

On the other hand, when the lower spring 316 contracts, the upper end of the lower spring 316 generates an urging force to contract in a direction opposite to the winding direction, and when the lower spring 316 expands, the lower spring 31
6 generates an urging force to contract along the winding direction.

In the internal combustion engine according to the present embodiment, the upper spring 314
Even when the urging force of the lower spring 316 acts on the shaft member 310, a rotation resistance is generated in the shaft member 310 and the rotation thereof is prevented. Therefore, the occurrence of damage and noise due to the rotation of the armature 311 is suppressed.

[0075]

In the internal combustion engine according to the present invention, at least the portion of the shaft member that is slidably in contact with the bearing portion has a shaft cross-sectional shape whose distance from the axis to one point on the outer circumference and the distance from the axis to the outer circumference. It is formed so that the distances to the other points above are different from each other. Further, the shaft member is supported so as not to allow continuous rotation to the bearing portion so that at least one point on the outer periphery located at a position where the distance from the shaft center is smaller than the maximum distance to the outer periphery is in contact. I have. Therefore, unnecessary rotation of the mover attached to the shaft member is suppressed, and interference between the mover and the housing for accommodating the mover, which accompanies the rotation of the mover, and other structures is eliminated. Damage to surrounding structures can be prevented.

[Brief description of the drawings]

FIG. 1 is a plan view showing a schematic configuration of an internal combustion engine according to the present invention.

FIG. 2 is a sectional view showing a schematic configuration of an internal combustion engine according to the present invention.

FIG. 3 is a diagram showing an internal configuration of an intake-side electromagnetic drive mechanism.

FIG. 4 is a perspective view showing an armature.

FIG. 5 is a perspective view showing a first core through which a shaft member is inserted;

FIG. 6 is a perspective view showing a pin pressed into a groove provided in the shaft member.

FIG. 7 is a sectional view of a portion of the shaft member into which a pin is inserted.

FIG. 8 is a perspective view showing a state where a shaft member is inserted into a first core.

FIG. 9 is a sectional view showing an axial section of the shaft member.

FIG. 10 is a diagram illustrating an example of a state in which a shaft member is supported by a bearing unit.

FIG. 11 is a diagram showing a state in which an armature and a housing for accommodating the armature interfere with each other.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine 20 ... ECU 25 ... Spark plug 26 ... Intake port 27 ... Exhaust port 28 ... Intake valve 28a ... Valve body 28b ... Valve shaft 29 ... Exhaust valve 30 ... Intake side electromagnetic drive mechanism 30a ... Intake side drive circuit 31 ... Exhaust side electromagnetic drive mechanism 31a ... Exhaust side drive circuit 310 ... Shaft member 310a, 310b ... Groove 319 ... Bearing 322 Pin 323 Notch groove

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shoji Katsumada 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Keiji Yoeda 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Masato Ogiso 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Hideyuki Nishida 1 Toyota Town Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tomomi Yamada Aichi 1 Toyota Town, Toyota City F-term (reference) in Toyota Motor Corporation 3G018 AA06 AB09 AB16 BA38 CA12 DA24 DA30 DA36 DA41 DA68 DA69 DA83 FA01 FA07 GA22 GA32

Claims (5)

[Claims] The valve body comprises: a shaft member that holds an armature displaced by electromagnetic force and transmits electromagnetic force to a valve body; and a bearing portion that supports the shaft member slidably in an axial direction. An internal combustion engine having an electromagnetically driven valve that drives using an electromagnetic force, wherein at least a portion of the shaft member that is slidably contacted with a bearing portion has a shaft cross-sectional shape from the axis to one point on the outer periphery. The distance and the distance from the axis to another point on the outer circumference are formed to be different from each other, and the shaft member is located on the outer circumference at a position where the distance from the axis is smaller than the maximum distance to the outer circumference. An internal combustion engine characterized in that at least one point is in contact with the bearing and is supported by the bearing so as not to allow continuous rotation. 2. The internal combustion engine according to claim 1, wherein the shaft member has a circular cross-sectional shape having a protrusion on an outer periphery. 3. The internal combustion engine according to claim 1, wherein the shaft member has a polygonal cross-sectional shape. 4. The internal combustion engine according to claim 1, wherein the shaft member has an elliptical cross-sectional shape. 5. The internal combustion engine according to claim 1, wherein said bearing portion corresponds to a shaft sectional shape of said shaft member, and has substantially the same shape as said shaft sectional shape.