JPH06129219A - Valve opening and closing device - Google Patents

Abstract

PURPOSE:To provide a valve opening and closing device which can prevent occurrence of bounce by damping the impingement of a valve element against valve seat when the valve element is closed from its opened condition. CONSTITUTION:A disc-like spring retainer part 26D is formed on a valve element 26, near to the proximal end than a valve spring retainer part 26C, and a damper spring 27 having a spring force in a direction revere to that of a valve spring 26, which is weaker than that of the spring 6. The damper spring retainer part 26D of the valve element 26 abuts against the front end of the damper spring 27, and accordingly, the valve element 26 is seated on a valve seat while resiliently deforming the damper spring 17, and accordingly the seating speed of the valve element 16 is retarded, thereby it is possible to prevent the valve element from bouncing after it is seated on the valve seat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve opening / closing device suitable for use as an intake / exhaust valve of an automobile engine, for example.

[0002]

2. Description of the Related Art Generally, an intake valve for supplying an air-fuel mixture to a combustion chamber defined in a cylinder of an automobile engine and an exhaust valve for exhausting combustion gas after combustion have an uneven portion in a radial direction of a shaft. A mechanical valve opening / closing device that opens and closes the valve by rotating the cam was used.

However, today, as engine performance has increased, the number of revolutions has become higher, and mechanical valve opening / closing devices cannot follow the opening / closing operation of the valve with respect to the reciprocating movement of the piston. Therefore, it becomes impossible to accurately control the inflow amount and the exhaust amount of the air-fuel mixture supplied to the combustion chamber. Therefore, in order to increase the opening / closing speed of the valve to surely open / close the valve, for example, Japanese Patent Laid-Open No. 2-1
A valve opening / closing device using a giant magnetostrictive actuator is known as disclosed in Japanese Patent No. 42979.

First, a valve opening / closing device using a giant magnetostrictive actuator as a drive mechanism will be shown and described as a conventional technique with reference to FIGS. 17 and 18.

In the figure, reference numeral 1 denotes a cylinder head as a valve seat member provided on a cylinder (not shown) of an engine body. Below the cylinder head 1, a piston positioned in the cylinder is provided. A combustion chamber 2 is defined between the combustion chamber 2 and any of them (not shown), and an opening portion 4 having a valve seat 3 communicating with the combustion chamber 2 is formed in the cylinder head 1.

Reference numeral 5 denotes a valve element which is seated on and off the valve seat 3 in order to open and close the opening 4 of the cylinder head 1. The valve element 5 is formed on the valve shaft 5A and on the tip side of the valve shaft 5A. And a disc-shaped valve spring receiving portion 5C formed on the base end side of the valve shaft 5A.

Reference numeral 6 denotes a valve spring, which is held between the valve spring receiving portion 5C of the valve body 5 and the outside of the opening 4 of the cylinder head 1, and the valve spring 6 is held by the valve body 5. Is always closed.

Reference numeral 7 is a giant magnetostrictive actuator as a drive mechanism, and 8 is a casing constituting the giant magnetostrictive actuator 7. Inside the casing 8, a coil 9 is excited by a control pulse from a control pulse generating means (not shown).
And a plurality (for example, 6) of giant magnetostrictive shafts 10A to 1
0F and the end faces of the giant magnetostrictive shafts 10A to 10F are roughly configured by five levers 11A to 11E having a length ratio of 1: 2, for example.

Here, the giant magnetostrictive shafts 10A-10
One end surface of the giant magnetostrictive shaft 10A, which is the starting point of F, is a fixed portion 8A that is a fixed end formed in the casing 8.
The other end face of the lever 11A abuts on the short side of the lever 11A, and one end face of the next giant magnetostrictive shaft 10B is attached to the lever 11A.
The long end of A is in contact with the other end face of the short end of the lever 11B. In this way, the giant magnetostrictive shafts 10 are sequentially arranged between the levers 11.

Then, in the end of the giant magnetostrictive shaft 10F, one end face is brought into contact with the longitudinal portion of the lever 11E,
The other end surface is in contact with the transmission shaft 12, which is a free end. Here, the transmission shaft 12 is inserted into the insertion hole 8B of the casing 8 and protrudes to the outside, so that the valve shaft 5 of the valve body 5
It is provided so as to come into contact with A via the cushioning member 13.

Reference numeral 14 denotes a preload spring. The preload spring 14 is held between the inside of the insertion hole 8B and the spring holding portion 12A of the transmission shaft 12, and inside the casing 8 via the levers 11A to 11E. Giant magnetostrictive shaft 1
Preload is applied to 0A to 10F.

When a control pulse is applied to the coil 9 of the giant magnetostrictive actuator 7 by the control pulse generating means, a magnetic field is generated in the coil 9, and the giant magnetic field causes each giant magnetostrictive shaft 10 to expand. There is.

At this time, the extension of the giant magnetostrictive shaft 10A, one of which is a fixed end, is transmitted to the giant magnetostrictive shaft 10B as a double extension by the lever 11A, and in the giant magnetostrictive shaft 10B, its own extension and the giant magnetostrictive shaft 10B. The extension from 10A is transmitted to the giant magnetostrictive shaft 10C as a double extension by the lever 11B. Thus, the giant magnetostrictive shaft 10
By the A to 10F and the levers 11A to 11E, the extension amounts of the giant magnetostrictive shafts 10A to 10F are integrated and added, and the extension amount of the transmission shaft 12 as the free end can be increased.

In the valve opening / closing device according to the prior art constructed as described above, when a control pulse is applied to the coil 9 of the giant magnetostrictive actuator 7 from the control pulse generating means, a magnetic field is generated by the coil 9. Each giant magnetostrictive shaft 10 expands in accordance with the magnetic field, and the amount of displacement is increased by adding the extension dimension of each giant magnetostrictive shaft 10 by each lever 11, and the transmission shaft 12 connected to the endpoint giant magnetostrictive shaft 10F is moved. Move in the direction of arrow A.

Then, the valve shaft 5A of the valve element 5 is pushed by the transmission shaft 12 via the buffer member 13, and the valve element 5 is separated from the valve seat 3 against the valve spring 6 to open the valve.

On the other hand, when the application of the control pulse from the control pulse generating means is stopped, the magnetic field generated by the coil 9 is erased, the giant magnetostrictive shafts 10A to 10F are contracted, and the transmission shaft 12 is moved in the arrow B direction.

Then, the valve element 5 is seated on the valve seat 3 by the spring force of the valve spring 6 to close the valve. In addition,
The closed state of the valve body 5 is as shown by the solid line in FIG. 18, and the valve is closed after the trailing edge of the control pulse shown by the dotted line.

[0018]

By the way, in the above-mentioned prior art, in the valve closing operation, the control pulse applied to the coil 9 is stopped and the valve body 5 is seated on the valve seat 3.
Giant magnetostrictive shafts 10A to 1 in the giant magnetostrictive actuator 7
Since the contraction speed of 0F is faster than the return speed of the valve body 5 by the valve spring 6, the valve body 5 cannot follow the contraction speed of the transmission shaft 12 of the giant magnetostrictive actuator 7, and the transmission shaft 12 and the cushioning member. 13 is temporarily separated from each other, and at the moment when the valve portion 5B of the valve body 5 is seated on the valve seat 3, the valve portion 5B is struck against the valve seat 3 and, as shown by the alternate long and short dash line in FIG. There is a problem in that the valve element 5 jumps up and down on 3 (hereinafter referred to as “bounce”), and the valve cannot be closed reliably.

Further, due to this bounce, the valve cannot be closed reliably during the valve closing operation, so that when the mixture is considered as an intake valve for supplying the mixture into the combustion chamber 2, for example, an accurate intake amount mixture is obtained. There is a problem that it becomes impossible to supply energy.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide a valve opening / closing device capable of preventing the valve body from bouncing when the valve is closed.

[0021]

The feature of the configuration adopted by the first invention to solve the above-mentioned problems is that the valve body is seated on the valve seat member by the valve spring between the valve body and the drive mechanism. In order to alleviate the impact at this time, a buffer spring means is provided which is in the opposite direction to the valve spring and gives a spring force smaller than that of the valve spring to the valve body.

The feature of the structure adopted by the second invention is that the valve spring is provided between the valve body and the drive mechanism in order to reduce the impact when the valve body is seated on the valve seat member by the valve spring. In the opposite direction, magnets having the same poles facing each other are provided so as to give a repulsive force smaller than that of the valve spring to the valve body.

[0023]

With the above construction, when the valve body is seated on the valve seat, the buffer spring means comes into contact with the valve body to start elastic deformation, and buffers the momentum of the valve body colliding with the valve seat before it is seated on the valve seat. Can be seated.

Further, according to the second structure, when the valve body is seated on the valve seat, the magnets having the same poles facing each other approach each other while narrowing the gap therebetween to generate a repulsive force, and the repulsive force causes the spring of the valve spring. The forces can be offset to buffer the momentum that the valve body collides with the valve seat.

[0025]

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

In the embodiment, the same components as those of the above-mentioned prior art are designated by the same reference numerals and the description thereof will be omitted.

First, FIGS. 1 to 4 show a first embodiment of the present invention.

In the figure, reference numeral 21 denotes a cylinder head as a valve seat member, and a through hole 21A is vertically formed in the cylinder head 21, and a valve seat 22 is provided below the through hole 21A. The opening 23 is formed obliquely, and the opening 23 and the through hole 21 </ b> A meet on the upper side of the valve seat 22. The cylinder head 21 is mounted on a cylinder (not shown) in the same manner as the cylinder head 1 of the prior art, and a combustion chamber 24 is defined below the cylinder head 21.

Reference numeral 25 denotes a cylindrical support member fitted into the through hole 21A from the upper side of the cylinder head 21 toward the opening 23, and the support member 25 has a valve body 26 described later.
The valve shaft 26A is supported slidably.

Reference numeral 26 denotes the opening 2 of the cylinder head 21.
In order to open and close 3
Although the valve element 26 has a valve shaft 26A, a valve portion 26B, and a valve spring receiving portion 26C, which is similar to the valve element 5 described in the prior art, the valve element 26 according to the present embodiment has a valve spring receiving portion 26C. A disk-shaped buffer spring receiving portion 26D, which is substantially the same as the valve spring receiving portion 26C, is provided on the proximal side. Then, the valve body 26 includes the valve spring receiving portion 26C and the cylinder head 2
It is attached to the cylinder head 21 in a vertically movable state via a valve spring 6 provided between the cylinder head 21 and the valve spring 1.

Reference numeral 27 denotes a buffer spring as a buffer spring means according to this embodiment, and the buffer spring 27 is the transmission shaft 12.
Of the valve body 26, the base end side of which is fixed to the casing 8 of the giant magnetostrictive actuator 7 and the front end side of which is located outside in the radial direction.
It is arranged so as to face the buffer spring receiving portion 26D.
When the valve body 26 is completely separated from the valve seat 22 and opened, the buffer spring 27 has a free length as shown in FIG. 1 and has a length L1 from the base end to the tip end, and the tip end is the valve end. Body 2
6 is separated from the buffer spring receiving portion 26D. Further, as shown in FIG. 2, the buffer spring 27 has a buffer spring receiving portion 26 on the front end side while the valve body 26 is moving in the valve closing direction.
When the valve body 26 comes into contact with D and the valve body 26 starts to elastically deform as it approaches the valve seat 22, the valve body 26 is compressed to a length L2 (L2 <L1) as shown in FIG. . Further, at this time, the buffer spring 27 is designed to apply a weaker spring force to the valve body 26 in the direction opposite to the valve spring 6 and to be weaker than the valve spring 6.

The valve opening / closing device according to this embodiment has the above-mentioned structure, and its operation will be described below.

First, when a control pulse is applied to the giant magnetostrictive actuator 7, the transmission shaft 12 is drawn out from the casing 8 of the giant magnetostrictive actuator 7 with a protrusion dimension P1, and the buffer body 26 of the valve body 26 is pushed. Is released from the valve seat 22 to open the valve. On the other hand, when the control pulse is stopped and the valve is closed, the transmission shaft 12 of the giant magnetostrictive actuator 7 is displaced to the casing 8 side, and the transmission shaft 12 quickly projects from the projection size P1 to P2 (P1> P2).
).

At this time, although the valve body 26 is biased by the valve spring 6 and displaced toward the valve seat 22, the displacement of the transmission shaft 12 is faster than the displacement speed of the valve body 26. As shown in FIG. 7, the tip of the transmission shaft 12 is moved to the cushion spring receiving portion 26 before the valve portion 26B of the valve body 26 is seated on the valve seat 22.
It separates from D. Here, the valve body 26 moves toward the valve seat 3 by the spring force of the valve spring 6, but at this time, the buffer spring 27 contacts the buffer spring receiving portion 26D, and the valve body 26 deforms the buffer spring 27, Since it is moving, the moving speed of the valve body 26 by the valve spring 6 is reduced. Then, as shown in FIG. 3, the valve seat 22 is slowly seated.

Thus, in this embodiment, the casing 8 of the giant magnetostrictive actuator 7 and the buffer spring receiving portion 26D of the valve body 26 are provided.
A buffer spring 27 having a spring force weaker than that of the valve spring 6 is provided between and in the opposite direction to the valve spring 6, so that the valve element 26 is seated on the valve seat 22 (point C in FIG. 4). Then, the buffer spring receiving portion 26D of the valve body 26 abuts on the tip of the buffer spring 27,
The valve body 26 elastically deforms the buffer spring 27,
At the moment of sitting on the valve seat 22, the speed is relaxed so as not to jump, and the seat is slowly seated at point D in FIG. here,
Since the valve body 26 is decelerated immediately before it is seated on the valve seat 22,
The relationship between the lift amount H of the valve portion 26B of the valve body 26 from the valve seat 22 and the time t is as shown in the characteristic diagram of FIG. 4, and the bounce occurs after the valve body 26 is seated on the valve seat 22. It can be prevented from occurring.

Therefore, according to the valve opening / closing apparatus of this embodiment, the valve opening / closing operation can be reliably performed even if the engine speed increases, and the engine performance can be improved.

Next, FIG. 5 shows a second embodiment of the present invention, which is characterized in that a disc spring is used as the buffer spring means. In the present embodiment, the same components as those of the above-mentioned conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, 31 indicates a valve body, which is substantially the same as the valve body 26 of the first embodiment and has a valve shaft 31A,
It has a valve portion 31B, a valve spring receiving portion 31C, and a buffer spring receiving portion 31D.

Reference numeral 32 denotes a cylindrical spacer fixed to the casing 8 of the giant magnetostrictive actuator 7.
Transmission shaft 1 of giant magnetostrictive actuator 7 from inside 2
2 is to be paid out. The spacer 32 supports a disc spring 33 described later on the tip side thereof.

Reference numeral 33 denotes a disc spring as a buffer spring according to the present embodiment, and the disc spring 33 has an outer peripheral side having the spacer 32.
And is disposed between the tip of the spacer 32 and the buffer spring receiving portion 31D of the valve body 31 in a state in which the inner peripheral side projects toward the tip side, that is, the valve body 31 side. Then, the disc spring 33
Allows the valve body 31 to be seated on the valve seat 3 while being elastically deformed, with the tip end side contacting the buffer spring receiving portion 31D when the valve body 31 is biased by the valve spring 6 and seated on the valve seat 3. . At this time, the disc spring 33 applies a spring force weaker than the valve spring 6 to the valve body 31 in the direction opposite to the valve spring 6.

The present embodiment has the structure as described above, and it is possible to obtain substantially the same operational effect as that of the first embodiment by this embodiment.

Next, FIGS. 6 to 9 show a third embodiment of the present invention. The feature of this embodiment is that an enlarged diameter portion is provided in the middle of the valve shaft of the valve body, and on the enlarged diameter portion. An annular spring that generates a spring force when elastically deforming in the radial direction is provided. In the embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 41 denotes a cylinder head as a valve seat member, and the cylinder head 41 communicates with the through hole 41A and the through hole 41A in the same manner as the cylinder head 21 in the first embodiment described above. An opening 43 having a valve seat 42 is formed on the lower side. The cylinder head 41 is mounted on a cylinder (not shown), and a combustion chamber 44 is defined below the cylinder head 41.

Reference numeral 45 designates a valve body, which is substantially the same as the valve body 26 according to the first embodiment described above.
Although it has A, a valve portion 45B, and a valve spring receiving portion 45C,
In the valve body 45 according to the present embodiment, a collar-shaped enlarged diameter portion 46 is formed on the valve shaft 45A and is located closer to the base end side than the valve spring receiving portion 45C, and a substantially conical shape is provided above the enlarged diameter portion 46. -Shaped conical portion 46A
Are formed. Then, the valve element 45 is connected to the valve spring receiving portion 4
5C and the cylinder head 41 via the valve spring 6,
It is attached to the cylinder head 41 in a vertically movable state.

Reference numeral 47 denotes a guide member provided on the base end side of the valve body 45, and the guide member 47 has a guide hole 47.
The valve shaft 45A of the valve body 45 is inserted into the guide hole 47A. Then, the valve shaft 45A penetrates the guide hole 47A and extends upward in the drawing,
The upper end of A is connected to the transmission shaft of a giant magnetostrictive actuator (not shown).

Reference numeral 48 denotes a C-shaped spring as a buffer spring provided on the expanded diameter portion 46, and the C-shaped spring 48 has one gap G in the circumferential direction as shown in FIG. , A substantially circular shape having an insertion hole 48A having a diameter dimension E provided in the center, and the C-shaped spring 48 expands the gap G when the conical portion 46A of the expanded diameter portion 46 is inserted into the insertion hole 48A. The insertion hole 48A elastically deforms so that the diameter E of the valve shaft 4 increases.
A spring force smaller than that of the valve spring 6 is applied to the enlarged diameter portion 46 on 5A in the direction opposite to the valve spring 6.

The valve opening / closing device according to this embodiment is constructed as described above, and its operation will be described below.

First, when the valve opening operation is performed, a control pulse is applied from the control pulse generating means to the giant magnetostrictive actuator, the transmission shaft of the giant magnetostrictive actuator is extended, and the valve body 45 pushes the valve shaft 45A onto the transmission shaft. Then, the valve seat 42 is separated from the valve seat 42 to open the valve. At this time, the gap G of the C-shaped spring 48 is reduced and the insertion hole 48A is reduced in diameter, whereby the C-shaped spring 48 is placed outside the valve shaft 45A. It fits and moves downward together with the valve shaft 45A.

When the valve closing operation is performed, the valve shaft 4
5A is urged by the valve spring 6 to move upward in the figure, and at this time, the C-shaped spring 48 moves the guide member 47 as shown in FIG.
The valve shaft 4 is abutted against the valve shaft 4 and is restricted from moving upward.
When 5A moves upward, the C-shaped spring 48 moves the conical portion 4
6A expands the diameter dimension of the insertion hole 48A of the C-shaped spring 48 from E to F (E <F). At this time, the valve shaft 45A is in the direction opposite to the spring force of the valve spring 6, A spring force smaller than that of the spring 6 is applied.

Thus, according to this embodiment as well, the C-shaped spring 48 is elastically deformed to relax the momentum when the valve element 45 is seated on the valve seat 42, and then it can be seated on the valve seat 42. The occurrence of bounce can be prevented.

In the third embodiment, the case where the C-shaped spring 48 is used as the buffer spring means is shown as an example. Instead of this, the coil spring starting end 49A as shown in FIG. An annular spring 49 formed by joining the winding end ends 49B may be used, and in this case, the annular spring 49 expands and contracts the intervals of the coil springs to generate a spring force.

Next, FIGS. 10 to 13 show a fourth embodiment. The feature of the present embodiment is that a bulging portion in the radial direction is provided in the middle of the valve shaft, and the bulging portion is provided on the outside in the radial direction of the protruding portion. Is that a buffer spring is provided through a sliding member having an inclined surface that is in sliding contact with the protrusion. In the embodiments, the same components as those of the conventional technique are designated by the same reference numerals, and the description thereof will be omitted.

In the figure, reference numeral 51 denotes a valve body, which is substantially the same as the valve body 5 described in the above-mentioned prior art, and has a valve shaft 51A,
Although having a valve portion 51B and a valve spring receiving portion 51C, a spherical protrusion 52 is formed on the valve shaft 51A of the valve body 51 on the proximal side of the valve spring receiving portion 51C.

Reference numeral 53 denotes a bracket for supporting a spring mechanism 54, which will be described later, and the bracket 53 is provided with an insertion hole 53A into which the valve shaft 51A is inserted. Then, the base end side of the valve shaft 51A is inserted into the insertion hole 53A, and the valve shaft 51A is connected to the transmission shaft 12 of the not-shown giant magnetostrictive actuator via the buffer member 13.

Reference numeral 54 represents a spring mechanism as a buffer spring means according to this embodiment, and the spring mechanism 54 is a holder 5 described later.
5, a sliding member 56, a stopper 57, a spring 58 and the like.

Reference numeral 55 denotes a holder which holds the sliding member 56, the spring 58 and the like inside and constitutes the outer frame of the spring mechanism 54.
The holder 55 is formed in a substantially box shape, and has valve shaft insertion holes 55A and 55B on the upper and lower sides and stopper insertion holes 55C and 5 on the left and right sides.
5C is drilled. Here, the valve shaft insertion hole 55B located on the lower side has a large diameter so that the protrusion 52 of the valve shaft 51A can pass through.

Reference numerals 56 and 56 denote sliding members slidably inserted in the holder 55. The tip ends of the sliding members 56 face each other in the holder 55 with the valve shaft 51A interposed therebetween, and the sliding members 56 and 56 slide. The inclined surface 5 is formed so that the space between the members 56 expands downward.
6A is formed. On the other hand, rod-shaped stoppers 57, 57 having a flange portion 57A are provided in a projecting manner on the base end side of each sliding member 56, and these stoppers 57 are slidably projected from the stopper insertion holes 55C, 55C of the holder 55. ing. When the sliding members 56 are urged by the springs 58 described later and pressed against the valve shaft 51A, the flanges 57A of the stoppers 57 abut the holder 55 to move the sliding members 56. It regulates, and each sliding member 56 makes the valve shaft 51A.
Is prevented from being pressed too much.

Reference numerals 58 and 58 denote the sliding members 5 in the holder 55.
6 shows a spring provided on the base end side of the sliding member 6, each spring 58 urges each sliding member 56 toward the center side, and the slanted surface 56A of each sliding member 56 is diagonally above the protrusion 52 of the valve shaft 51A. It is designed to come into contact with each other.

The valve opening / closing device according to this embodiment has the above-mentioned structure, and its operation will be described below.

First, when the valve opening operation is performed, the transmission shaft 12 of the giant magnetostrictive actuator is fed out by the control pulse applied from the pulse control means, and the valve shaft 51A of the valve body 51 is transmitted through the buffer member 13 to the transmission shaft 12. Then, the valve is opened as shown in FIG.

When the valve closing operation is performed, the valve shaft 5
1A is urged by the valve spring 6 to move upward in the drawing, and at this time, the projection 52 provided on the valve shaft 51A of the valve body 51 moves into the valve shaft insertion hole 55B of the holder 55 and Sliding member 5
6 between the inclined surfaces 56A, the sliding members 56 are separated in the left-right direction while slidingly contacting the inclined surfaces 56A, and the springs 58 are contracted. At this time, each spring 58 is connected to the valve shaft 51A.
In the direction opposite to the valve spring 6 with respect to the protrusion 52 of
It is designed to apply a smaller spring force.

Thus, also in this embodiment, immediately before the valve body 51 is seated on the valve seat 3, the speed at which the valve body 51 moves toward the valve seat 3 is reduced, so that the valve body 51 is seated on the valve seat 3. After that, bounce can be prevented from occurring, the valve opening / closing operation can be reliably performed even when the engine speed increases, and the engine performance can be improved.

Next, FIGS. 14 to 16 show the fifth embodiment of the present invention.
This embodiment is characterized in that the valve body and the giant magnetostrictive actuator are provided with magnets so that the same poles face each other. In the embodiment, the same components as those in the first embodiment described above are designated by the same reference numerals and the description thereof will be omitted.

In the figure, reference numeral 61 denotes a valve body, and the valve body 61 has a valve shaft 61A, a valve portion 61B, and a valve spring receiving portion 61C, which is similar to the valve body 26 in the first embodiment. However, the valve spring receiving portion 61C is located closer to the base end side than the valve spring receiving portion 61C.
A disk-shaped magnet fixing portion 61D that is substantially similar to the above is provided.

Reference numeral 62 designates a cylindrical spacer fixed to the casing 8 of the giant magnetostrictive actuator 7.
Transmission shaft 1 of giant magnetostrictive actuator 7 from inside 2
2 is to be paid out.

Reference numerals 63 and 63 denote magnet fixing portions 6 of the valve body 61.
1D and an annular magnet fixed to the tip end side of the spacer 62 by means of adhesion or the like, the magnets 63 have the same poles facing each other, and when the valve body 61 is seated on the valve seat 22,
As shown in FIG. 6, the magnets 63 are fixed so that a gap J is formed between the magnets 63. At this time, a repulsive force smaller than the valve spring 6 and in the opposite direction to the valve spring 6 is applied to the spacer 62 and the magnet fixing portion 61D.

The present embodiment is constructed as described above, and its operation will be described below.

First, when a control pulse is applied to the giant magnetostrictive actuator 7, the transmission shaft 12 is extended from the casing 8 of the giant magnetostrictive actuator 7, and the valve body 61 is moved to the position shown in FIG.
4, the magnet fixing portion 61D is pushed by the transmission shaft 12 to separate from the valve seat 22 and open the valve.

When the valve closing operation is performed, the control pulse is stopped, and the transmission shaft 12 of the giant magnetostrictive actuator 7 is swiftly contracted as shown in FIG.

At this time, the valve body 61 is biased by the valve spring 6 and displaced toward the valve seat 22, but the displacement of the transmission shaft 12 is faster than the displacement speed of the valve body 61.
As shown in FIG. 2, the tip of the transmission shaft 12 is moved to the cushion spring receiving portion 2 before the valve portion 61B of the valve body 61 is seated on the valve seat 22.
It is separated from 6D. The valve body 61 is the valve spring 6
Although it moves to the valve seat 3 side due to the spring force of 1, the magnet 63 provided in the magnet fixing portion 61D of the valve body 61 is weaker than the valve spring 6 between the magnet 63 provided in the casing 8 and the reverse direction. Of the valve seat 2 while decelerating the valve body 61.
2 can be seated.

Thus, in this embodiment, the spacer 62 and the valve body 61 provided on the casing 8 of the giant magnetostrictive actuator 7 are used.
Since the annular magnets 63, 63 that generate a repulsive force weaker than the valve spring 6 are provided between the magnet fixing portion 61D and the magnet fixing portion 61D, when the valve body 61 is seated on the valve seat 3, as shown in FIG.
As shown in FIG. 6, it is possible to prevent a bounce by seating with a gap J between the magnets 63, 63, and relaxing the speed of the valve body 61 immediately before the valve body 61 is seated on the valve seat 22. You can

Therefore, the valve opening / closing device according to the present embodiment can surely perform the opening / closing operation of the valve, and can improve the performance of the engine.

In each of the above embodiments, the case where the giant magnetostrictive actuator is used as the drive mechanism for driving the valve body in the valve opening direction has been shown and described as an example, but the present invention is not limited to this. It may be used for a valve opening / closing device using a cam as a drive mechanism.

[0074]

As described in detail above, according to the present invention, the valve spring is provided between the valve body and the drive mechanism in order to reduce the impact when the valve body is seated on the valve seat member by the valve spring. In the opposite direction to the above, since the buffer spring means for providing the valve body with a spring force smaller than that of the valve spring is provided, when the valve body is seated on the valve seat, the buffer spring means comes into contact with the valve body to start elastic deformation. The momentum of the valve body colliding with the valve seat can be buffered and then the valve body can be seated on the valve seat, and bounce can be prevented.

Further, in order to absorb the impact between the valve body and the drive mechanism when the valve body is seated on the valve seat member by the valve spring, the repulsive force is in the opposite direction to the valve spring and smaller than the valve spring. By arranging magnets with the same poles facing each other so as to give the same to the valve body, when the valve body is seated on the valve seat, the same poles of the magnets approach each other while narrowing the interval to generate a repulsive force. By the repulsive force, the spring force of the valve spring can be offset to buffer the force of the valve body colliding with the valve seat, and bounce can be prevented.

Therefore, according to the present invention, even when the valve is frequently opened and closed, it is possible to suppress the occurrence of bounce and to surely perform the opening and closing operation of the valve, thereby improving the certainty and stability of the operation. It is possible to provide a valve opening / closing device.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing a valve open state of a valve opening / closing device according to a first embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view showing a state of the valve opening / closing device shown in FIG. 1 during valve closing.

FIG. 3 is a vertical cross-sectional view showing a valve closed state of the valve opening / closing device shown in FIG.

FIG. 4 is a characteristic diagram showing a relationship between a valve lift amount and time of the valve opening / closing device shown in FIG.

FIG. 5 is a vertical cross-sectional view showing a valve opening / closing device according to a second embodiment of the present invention.

FIG. 6 is a vertical sectional view showing a valve open state of a valve opening / closing device according to a third embodiment of the present invention.

FIG. 7 is a plan view showing a C-shaped spring in FIG.

8 is a vertical cross-sectional view showing a closed state of the valve opening / closing device shown in FIG.

FIG. 9 is a plan view showing a spring used in a modified example of the buffer spring means according to the third embodiment.

FIG. 10 is a vertical cross-sectional view showing a valve open state of a valve opening / closing device according to a fourth embodiment of the present invention.

11 is a sectional view taken along the line XI-XI in FIG.

12 is a vertical cross-sectional view showing the valve opening / closing device shown in FIG. 10 when the valve is closed.

FIG. 13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is a vertical cross-sectional view showing a valve open state of a valve opening / closing device according to a fifth embodiment of the present invention.

15 is a vertical cross-sectional view showing a state of the valve opening / closing device shown in FIG. 14 during valve closing.

16 is a vertical cross-sectional view showing a valve closed state of the valve opening / closing device shown in FIG.

FIG. 17 is a vertical sectional view showing a valve opening / closing device according to a conventional technique.

FIG. 18 is a characteristic diagram showing a relationship between a valve lift amount and time of a valve opening / closing device according to a conventional technique.

[Explanation of symbols]

 1,21,41 Cylinder head (valve seat member) 3,22,42 Valve seat 4,23,43 Opening 26,31,45,51,61 Valve body 6 Valve spring 7 Giant magnetostrictive actuator (drive mechanism) 27 Buffer Spring (buffer spring means) 33 Disc spring (buffer spring means) 48 C-shaped spring (buffer spring means) 49 Annular spring (buffer spring means) 54 Spring mechanism (buffer spring means) 63 Magnet

Claims (2)

[Claims] 1. A valve seat member having a valve seat formed in an opening,
A valve body that is seated on and off the valve seat to open and close the opening of the valve seat member; and the valve body is provided between the valve body and the valve seat member.
A valve opening and closing device comprising a valve spring for constantly urging the valve body in a valve closing direction and a drive mechanism for driving the valve body in the valve opening direction against the valve spring. In between, a buffer spring, which is in a direction opposite to the valve spring and exerts a spring force smaller than that of the valve spring on the valve body, in order to absorb an impact when the valve body is seated on the valve seat member by the valve spring. A valve opening / closing device, characterized in that means is provided. 2. A valve seat member having a valve seat formed in an opening,
A valve body that is seated on and off the valve seat to open and close the opening of the valve seat member; and the valve body is provided between the valve body and the valve seat member.
A valve opening and closing device comprising a valve spring for constantly urging the valve body in a valve closing direction and a drive mechanism for driving the valve body in the valve opening direction against the valve spring. In between, in order to absorb the impact when the valve body is seated on the valve seat member by the valve spring, a repulsive force smaller than the valve spring is applied to the valve body in the opposite direction to the valve spring. A valve opening / closing device in which magnets having the same poles facing each other are arranged.