JP2000091119A - Electromagnetic driving system valve operating apparatus in electromagnetic driving equipment and internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electromagnetic driving system valve operating apparatus which copes with progress of the deterioration with time of a return spring of an armature and can continue stable operation. SOLUTION: (1) The maximum stress σB applied to an opening valve side return spring 10 at the time of compression of the opening valve side return spring 10 is set smaller than the maximum stress σA applied to a closing valve side return spring 9 at the time of compression of a closing valve side return spring 9 (σA>σB). (2) The ratio of σA:σB is set nearly equal to the ratio of a closing valve time to an opening valve time. (3) The ratio of σA:σB is set, e.g. nearly equal to 2:1 which is the ratio of the closing valve time to the opening valve time. (4) The number of the opening valve side return springs 10 is set larger than that of the closing valve side return springs 9. (5) The settling strength of the opening valve side return spring 10 is set larger than that of the closing valve side return spring 9. (6) The settling rate of the closing valve side return spring 9 after a closing valve time t2 has passed is set nearly equal to the settling rate of opening valve side spring 10 after an opening valve time t1 has passed. (7) The ratio of the closing valve time t2 to the opening valve time t1 in (6) is set nearly equal to 2:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic drive device and an electromagnetically driven valve train in an internal combustion engine, and more particularly to a technique for stabilizing the operation.

[0002]

2. Description of the Related Art As an electromagnetic drive device, an electromagnetic drive valve device for driving a valve such as an intake / exhaust valve of an internal combustion engine has been conventionally used.
An armature provided on the stem of the valve, a pair of electromagnets respectively disposed on both side surfaces of the armature to apply an electromagnetic attraction to the armature, that is, a valve-opening electromagnet and a valve-closing electromagnet, and the armature. It is configured to include a pair of return springs biasing both electromagnets, that is, a valve-opening-side return spring and a valve-closing-side return spring (see Japanese Patent Application Laid-Open No. 7-335437).

In such an electromagnetically driven valve train, in order to uniformly apply the electromagnetic attraction force of the valve-opening electromagnet and the valve-closing electromagnet to the armature, the valve-opening-side return spring and the valve-closing-side return spring have , Are set to the same specifications.

[0004]

As described above, in the conventional electromagnetic drive device in which the valve-opening-side return spring and the valve-closing-side return spring are set to the same specification, at the time of initial setting,
The vibration center (neutral point) of the spring vibration of the armature is located at the center position between the electromagnets that are substantially opposed to each other, and the electromagnetic attraction force of both electromagnets acts equally on the armature, so that there is no problem.

However, the neutral point shifts as the deterioration of the spring with time (set of the spring load) progresses. In an electromagnetically driven valve train that drives intake and exhaust valves of a normal internal combustion engine, the ratio between the valve closing time and the valve opening time is
The ratio is approximately 2: 1, and the time during which the valve-opening-side return spring is compressed when the valve is closed is longer than the time during which the valve-opening-side return spring is compressed when the valve is opened. The deterioration with time is greater than the deterioration with time of the valve-closing-side return spring, and the neutral point shifts to the valve-closing electromagnet side.As a result, the electromagnetic attraction force of the valve-opening electromagnet acting on the armature is weakened, and the armature is stabilized. In addition, there is a problem that the opening / closing operation is not performed stably, for example, the seating speed of the armature with respect to the valve-closing electromagnet increases when the valve is closed.

In view of the above-mentioned conventional problems, the present invention is directed to an electromagnetic drive device and an electromagnetic engine for an internal combustion engine, which are capable of maintaining a stable operation by employing a configuration which copes with the progress of the return spring of the armature with time. It is an object of the present invention to provide a driven valve train.

[0007]

For this purpose, the invention according to claim 1 comprises an armature, a pair of electromagnets arranged oppositely on both side surfaces of the armature and for applying electromagnetic attraction to the armature, and the armature. And a pair of return springs for urging the both return magnets toward both electromagnets, wherein the set resistance of one return spring to the other return spring is improved. And

According to a second aspect of the present invention, there is provided an armature provided on a valve body, and a valve-opening electromagnet and a valve-closing electromagnet which are respectively disposed on both sides of the armature to apply an electromagnetic attraction force to the armature. A valve-opening-side return spring and a valve-closing-side return spring for urging the armature toward both electromagnets, respectively. The maximum stress applied to the valve-opening return spring at the time of compression of the valve-opening-side return spring is set to be smaller than the maximum stress applied to the valve-closing-side return spring.

According to a third aspect of the present invention, the ratio between the maximum stress applied to the valve-closing-side return spring and the maximum stress applied to the valve-opening-side return spring is substantially equal to the ratio between the valve closing time and the valve opening time. It is characterized by having been set. The invention according to claim 4 is that the ratio of the maximum stress applied to the valve-closing-side return spring to the maximum stress applied to the valve-opening-side return spring is approximately two times, which is the ratio of the valve closing time to the valve opening time. The ratio is set to 1.

The invention according to claim 5 is characterized in that, instead of setting the maximum stress, the number of open-side return springs is set to be larger than the number of valve-close-side return springs. The invention according to claim 6 is characterized in that, instead of the setting of the maximum stress, the setting of the setting strength of the open-side return spring is larger than the setting strength of the valve-closing-side return spring.

According to a seventh aspect of the present invention, in accordance with the present invention, instead of the setting of the maximum stress, the set ratio of the valve-side return spring after the valve closing time has elapsed and the set ratio of the open-side return spring after the valve open time has elapsed. Are set to be substantially the same. The invention according to claim 8 is characterized in that the ratio between the valve closing time and the valve opening time is approximately 2: 1.

The operation of the present invention will be described. In the invention according to the first aspect, in the conventional electromagnetic drive device in which the pair of return springs are set to the same specifications, the neutral point increases as the deterioration with time of the spring (set of the spring load) progresses. Shift. According to the first aspect of the present invention, as the set resistance of the other return spring is increased with respect to the one return spring, the return spring with the increased set resistance is prevented from deteriorating with time, and the neutral state is improved. It is possible to prevent the points from shifting.

[0013] In a conventional electromagnetically driven valve train in an internal combustion engine in which the valve-opening-side return spring and the valve-closing-side return spring are set to the same specification, the deterioration of the spring with time (set of the spring load) occurs. As it proceeds, the neutral point shifts toward the valve-closing electromagnet. This is because, in the case of an electromagnetically driven valve train that drives intake and exhaust valves of a normal internal combustion engine, the ratio between the valve closing time and the valve opening time is, for example, approximately 2: 1. This is because the time during which the valve-side return spring is compressed is longer than the time during which the valve-side return spring is compressed when the valve is opened.

According to the second aspect of the invention, the maximum stress applied to the valve-opening-side return spring is set to be smaller than the maximum stress applied to the valve-closing-side return spring. The deterioration with time of the spring is suppressed, and the neutral point can be prevented from shifting to the valve-closing electromagnet side. In particular, as in the invention according to claims 3 and 4, the ratio between the maximum stress applied to the valve-closing-side return spring and the maximum stress applied to the valve-opening-side return spring is set to a value substantially equal to the valve closing time and the valve opening time. Ratio, for example, a ratio of approximately 2 to 1 (2: 1)
By doing so, it is possible to set the time taking into account that the time during which the valve-opening-side return spring is compressed when the valve is closed is longer than the time during which the valve-opening-side return spring is compressed when the valve is opened. , More effective.

According to the fifth and sixth aspects of the present invention,
As a result of setting the number of return springs on the open side larger than the number of return springs on the valve closing side, and setting the strength of the return spring on the open side larger than the strength of the return spring on the valve close side, the valve opens. The time-dependent deterioration of the side return spring can be suppressed, and the neutral point can be prevented from shifting to the valve-closing electromagnet side. Furthermore, according to the seventh and eighth aspects of the present invention, the setting rate of the set-side return spring after the valve closing time elapses and the setting rate of the open-side return spring after the valve opening time elapses are set to be substantially the same. As a result, regardless of the difference between the valve closing time and the valve opening time, the set rates of both return springs are substantially the same,
The aging of the valve-opening-side return spring (set of the spring load) is suppressed from progressing more than the aging of the valve-closing-side return spring, and the neutral point can be prevented from shifting to the valve-closing electromagnet side.

[0016]

According to the first aspect of the present invention, it is possible to suppress a change in the neutral point of the armature with respect to a change with time in the return spring load, and a stable operation of the electromagnetic drive device can be obtained. According to the second to eighth aspects of the present invention, in the electromagnetically driven valve train that drives the intake and exhaust valves of a normal internal combustion engine, deterioration over time (set of spring load) of the valve-opening-side return spring is suppressed. As a result, the neutral point can be suppressed from shifting to the valve-closing electromagnet side.As a result, the electromagnetic attraction force by the valve-opening electromagnet acting on the armature can be secured as in the initial setting, and the armature can be stably held and held.
When the valve is closed, the seating speed of the armature with respect to the valve-closing electromagnet can be prevented from increasing, and the opening and closing operations can be stably performed.

In particular, according to the second aspect of the present invention, the above operation can be more effectively achieved by setting the magnitude of the maximum stress applied to the return spring when the return spring is compressed. Further, according to the third and fourth aspects of the present invention, the setting can be made in consideration of the fact that the valve closing side return spring is longer than the compression time when the valve is opened, which is more effective.

According to the fifth aspect of the present invention, the above operation can be more effectively achieved by setting the number of return springs. According to the sixth aspect of the present invention, the above operation can be more effectively achieved by setting the set strength of the return spring by selecting the spring material of the return spring. According to the seventh and eighth aspects of the present invention, by selecting the spring material of the return spring, the set ratio of the valve-side return spring when the valve-closing time has elapsed and the set of the open-side return spring when the valve-open time has elapsed. By setting the ratio to be substantially the same, the above-described operation can be more effectively achieved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a longitudinal sectional view showing an embodiment of an electromagnetic drive device and an electromagnetically driven valve train in an internal combustion engine according to the present invention. That is, in this figure, a cylinder head 1 is provided with an intake port (exhaust port) that opens to a combustion chamber (not shown), and an electromagnetically driven valve gear 2 that opens and closes the intake port (exhaust port). ing.

The electromagnetically driven valve train 2 comprises a housing 3 made of a non-magnetic material provided on the cylinder head 1.
For example, a rectangular armature 6 provided integrally with the stem 5 of the valve body 4 and movably housed in the housing 3, and an electromagnetic force for sucking the armature 6 and closing the valve body 4. The valve-closing electromagnet 7 that is generated, the valve-opening electromagnet 8 that generates an electromagnetic force that attracts the armature 6 to open the valve element 4, and biases the armature 6 in the valve-closing direction of the valve element 4. The valve-closing-side return spring 9 and the valve body 4
And a valve-opening-side return spring 10 for urging the armature 6 in the valve-opening direction.

The valve-closing electromagnet 7 is fixedly arranged in the housing 3 at a position facing the upper surface of the armature 6 in the housing 3 and has a substantially U-shaped cross section open to the armature 6 side. And a coil 12 is housed in a fixed core 11 surrounding the stem 5 coaxially. The valve-opening electromagnet 8 is fixedly arranged in the housing 3 at a position facing the lower surface of the armature 6 in the housing 3 and has a substantially U-shaped cross-sectional shape opened to the armature 6 side. In addition, a coil 14 is housed in a fixed core 13 that coaxially surrounds the stem 5.

The fixed cores 11 and 13 are configured so as to correspond to the rectangular armature 6 and have a substantially rectangular cross-sectional shape having rounded corners at four corners. On the other hand, the valve-closing-side return spring 9 is fixed to the bottom surface of the storage groove 15 and the outer periphery of the lower portion of the stem 5 in the storage groove 15 on the upper surface of the cylinder head 1 so as to apply an upward spring force to the armature 6. And the spring seat 16 provided.

The valve-opening-side return spring 10 is provided in a housing 17 attached to the upper surface of the housing 3 so as to apply a downward spring force to the armature 6.
It is interposed between a spring seat 18 on the inner upper surface of the storage part 17 and a spring seat 19 fixed to the upper end of the stem 5. Therefore, when the two electromagnets 7 and 8 are in the demagnetized state, the two return springs 9 and 10 hold the armature 6 at an equilibrium neutral position in the central portion between the two electromagnets 7 and 8. Is located at an intermediate position between the valve closing position and the valve opening position.

The operation of the electromagnetically driven valve train 2 is shown in FIG.
With reference to the conceptual diagram of the device and the valve lift state diagram of FIG. 3, the armature 6 is attracted by an electromagnetic attraction force generated by energizing the valve closing electromagnet 7,
The valve body 4 is operated to close the valve (a fully closed state in FIG. 2A, see FIG. 3). At this time, the valve-closing-side return spring 9 is applying an upward spring force to the armature 6, while the valve-opening-side return spring 10 is in a compressed state.

Next, the armature 6 is attracted by the electromagnetic attraction force generated by energizing the valve-opening electromagnet 8, and the valve body 4 is opened (FIG. 2C, fully open state, FIG. 3). At this time, the valve-opening-side return spring 10
A downward spring force is applied to the armature 6, while the valve-closing-side return spring 9 is in a compressed state.

When shifting from the fully closed state to the fully opened state, the intermediate lift state shown in FIG.
As described above, the valve element 4 is located at a position intermediate between the valve closing position and the valve opening position (see FIG. 3). FIG. 4 is a longitudinal sectional view of an electromagnetically driven valve train of another embodiment. That is, the valve operating device 2 of this embodiment includes the valve-opening-side return spring 2
One of the valve-opening-side return springs 10B is disposed inside one of the valve-opening-side return springs 10A.
The two valve-opening-side return springs 10B and 10A are arranged in an inner and outer double arrangement state, and the valve-opening-side return springs 10 in the inner and outer double arrangement state are arranged.
B, 10A are applied to the spring seat 20 and the upper end of the stem 5 on the upper surface of the inside of the housing 17 in the housing 17 attached to the upper surface of the housing 3 so that a downward spring force acts on the armature 6. It is interposed between the fixed spring seat 21.

Here, in the present invention, the above electromagnetic drive
In the valve train 2, the following (1) to (7)
After setting, the valve-opening side return spring 1 is
Improves the sag resistance of 0. (1) When the valve-closing-side return spring 9 is compressed, the valve-closing-side return spring 9
The maximum stress σ applied to _AOf the return spring 10 on the valve opening side
Maximum stress σ applied to the valve-opening-side return spring 10 during compression
_BIs small (σ_A> Σ_B). (2) In (1), the voltage is applied to the valve-closing-side return spring 9.
Maximum stress σ_AAnd the maximum response applied to the valve-opening-side return spring 10.
Force σ_BRatio (σ_A: Σ_B), The approximate closing time and opening time
Set to ratio. (3) In (2), σ_A: Σ_BFor example, the valve closing time
And a valve opening time ratio of approximately 2: 1 (2: 1). (4) Opener than the number (for example, one) of the valve-closing-side return spring 9
Increase the number (for example, two) of the side return springs 10A and 10B.
(See the embodiment of FIG. 4). (5) Closed by selecting the spring material of both return springs 9 and 10.
The set strength of the open return spring 10 is smaller than the set strength of the valve side return spring 9.
Select a setting that increases the set strength. (6) Select the spring material of both return springs 9 and 10 to close
Valve time t_TwoSet-off rate and valve opening of the valve-closing-side return spring 9 during elapse
Time t₁The set rate of the open-side return spring 10 during the passage is approximately the same.
(See FIG. 5). (7) In (6), the valve closing time t_TwoAnd valve opening time t₁of
Set the ratio to approximately a 2 to 1 ratio.

According to this configuration, the following operation and effect can be obtained. That is, in a conventional electromagnetically driven valve device in which the valve-opening-side return spring and the valve-closing-side return spring are set to the same specifications, as the spring deteriorates with time (spring load sag), it progresses. , The neutral point shifts to the valve closing electromagnet side. This is because, in an electromagnetically driven valve train that normally drives intake and exhaust valves of an internal combustion engine, the ratio between the valve closing time and the valve opening time is approximately 2: 1. This is because the time during which the return spring is compressed is longer than the time during which the valve-closing-side return spring is compressed when the valve is opened.

According to the above setting (1), the maximum stress σ _B applied to the valve-opening-side return spring 10 is smaller than the maximum stress σ _A applied to the valve-closing-side return spring 9 (σ _A >
sigma _B) setting the result as, aging of the spring 10 the return opening side (sag spring load) is suppressed, can prevent the neutral point is shifted to a valve-closing electromagnet 7 side. In particular, as in the settings of (2) and (3), by setting σ _A : σ _B to a ratio between the substantially valve closing time and the valve opening time, for example, a ratio of approximately 2: 1 (2: 1). The setting can be made in consideration of that the time during which the valve-opening-side return spring 10 is compressed when the valve is closed is longer than the time during which the valve-closing-side return spring 9 is compressed when the valve is opened. It is valid.

According to the settings (4) and (5), the number (for example, two) of the open-side return springs 10A and 10B is larger than the number (for example, one) of the valve-closing-side return spring 9. As a result of setting the opening strength of the open-side return spring 10 to be larger than the strength of the valve-closing-side return spring 9, the valve-opening-side return springs 10, 10A, and 10B deteriorate over time (the spring load decreases). Sag) can be suppressed, and the neutral point can be prevented from shifting to the valve-closing electromagnet 7 side.

Further, according to the above settings (6) and (7), the set rate of the valve-side return spring 9 when the valve-closing time has elapsed and the set-back of the open-side return spring 10 when the valve-open time has elapsed. As a result of setting the rates to be substantially the same, the set rates of the two return springs 9 and 10 become substantially the same regardless of the difference between the valve closing time and the valve opening time. The deterioration (set of the spring load) is prevented from progressing more than the deterioration with time of the valve-closing-side return spring 9, and the neutral point can be suppressed from shifting to the valve-closing electromagnet 7 side.

Therefore, as described above, the valve-opening-side return spring 1
As a result, the electromagnetic attraction force to the armature 6 by the valve-opening electromagnet 8 is reduced as compared with the initial setting. Similarly, the armature 6 can be stably sucked and held, and the seating speed of the armature 6 with respect to the valve-closing electromagnet 7 can be prevented from increasing when the valve is closed, so that the opening and closing operations can be performed stably. it can.

In the above embodiment, the invention has been described in which the set resistance of the valve-opening-side return spring is improved with respect to the valve-closing-side return spring of the electromagnetically driven valve train. The invention according to claim 1 is an electromagnetic drive device that is not limited to driving a valve, that is, an armature, and a pair of electromagnets that are respectively arranged on both side surfaces of the armature so as to act on the armature by applying an electromagnetic attraction force, And a pair of return springs for urging the armature toward both electromagnets, wherein the set resistance of the other return spring is improved with respect to one of the return springs. It is possible to suppress a change in the neutral point of the armature with respect to a change with time in the set of the return spring load, and to obtain a stable operation of the electromagnetic driving device.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of an electromagnetic drive device and an electromagnetic drive valve device in an internal combustion engine according to the present invention.

FIGS. 2A and 2B are conceptual diagrams of the apparatus according to the embodiment, wherein FIG. 2A is a fully closed state, FIG. 2B is a fully opened state, and FIG.

FIG. 3 is a valve lift state diagram.

FIG. 4 is a longitudinal sectional view of another embodiment.

FIG. 5 is a characteristic diagram showing a set rate with time of the valve-opening-side return spring and the valve-closing-side return spring.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 cylinder head 2 electromagnetically driven valve gear 3 housing 4 valve body 5 stem 6 armature 7 valve closing electromagnet 8 valve opening electromagnet 9 valve closing side return spring 10 valve opening side return spring 10B, 10A valve opening side return spring

Claims (8)

[Claims] An armature, a pair of electromagnets disposed on both side surfaces of the armature to apply electromagnetic attraction to the armature, and a pair of return springs for urging the armature toward both electromagnets; An electromagnetic drive device comprising: a first return spring with respect to one return spring; 2. An armature provided on a valve body, a valve-opening electromagnet and a valve-closing electromagnet which are respectively arranged on both side surfaces of the armature so as to act on the armature by applying an electromagnetic attraction force, And a valve-opening return spring and a valve-closing-side return spring that respectively urge the valve-side return spring when the valve-closing-side return spring is compressed. An electromagnetically driven valve in an internal combustion engine, wherein the maximum stress applied to the valve-opening-side return spring when the valve-opening-side return spring is compressed is smaller than the maximum stress applied to the spring. apparatus. 3. A ratio between a maximum stress applied to the valve-closing-side return spring and a maximum stress applied to the valve-opening-side return spring is set to a substantially ratio between the valve closing time and the valve opening time. An electromagnetically driven valve train in an internal combustion engine according to claim 2. 4. A ratio of a maximum stress applied to the valve-closing-side return spring to a maximum stress applied to the valve-opening-side return spring is a ratio of a valve closing time to a valve opening time of approximately 2: 1. 4. An electromagnetically driven valve train in an internal combustion engine according to claim 3, wherein: 5. The electromagnetic system according to claim 2, wherein, instead of setting the maximum stress, the number of open-side return springs is set to be larger than the number of valve-close-side return springs. Driven valve train. 6. The method according to claim 2, wherein, instead of setting the maximum stress, the set strength of the open-side return spring is set to be larger than the set strength of the valve-closed return spring. An electromagnetically driven valve train in an internal combustion engine. 7. The set rate of the valve-side return spring after the valve closing time elapses and the set rate of the open-side return spring after the valve open time elapses, instead of setting the maximum stress. 3. An electromagnetically driven valve train in an internal combustion engine according to claim 2, wherein said valve train is set. 8. An electromagnetically driven valve train in an internal combustion engine according to claim 7, wherein the ratio between the valve closing time and the valve opening time is approximately 2: 1.