JP2013224628A - Electromagnetic actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electromagnetic actuator preventing a regulation pin from being unlocked by vibration or the like, in the electromagnetic actuator applied to a valve lift adjustment device of an internal combustion engine.SOLUTION: An electromagnetic actuator 401 switches a locked state that a regulation pin 601 is locked to be inoperable and a free state that the regulation pin 601 is made operable by an electromagnetic force generated by the electric conduction of a coil 42 and actuates the regulation pin 601 by an energizing force of a pin spring 74 in the free state. A latch plate 55 locking the regulation pin 601 by being fit into a latch groove 611 is provided to be reciprocally movable in a direction orthogonal to an axis of the regulation pin 601. Since movable directions of the latch plate 55 and the regulation pin 601 are orthogonal to each other, the unlocking of the regulation pin 601 by the vibration or the like of an internal combustion engine can be prevented.

Description

  The present invention relates to an electromagnetic actuator that is applied to a valve lift adjusting device for an internal combustion engine and switches a slider position by advancing a regulating pin to engage with an engaging groove.

  2. Description of the Related Art Conventionally, in a valve lift adjustment device that adjusts the lift amount of an intake valve or an exhaust valve of an internal combustion engine, the position of a slider provided so as to be movable relative to the camshaft in an axial direction while rotating together with the camshaft is known. It has been. Further, as a means for switching the position of the slider, an electromagnetic actuator is known in which a restriction pin is operated by an electromagnetic force or a spring force and a tip end portion of the restriction pin is fitted in an engagement groove formed in the slider.

For example, in the electromagnetic actuator described in Patent Document 1, the taper surface of the lock pin provided coaxially with the restriction pin makes the restriction pin inoperable by pressing a ball accommodated in the hole of the restriction pin against the inner wall of the sleeve. Lock it.
When operating the restriction pin, the lock pin is released by moving the lock pin in the pulling direction by the electromagnetic force of the coil, and the restriction pin is operated by the spring force.

DE 102008020892A1 specification

In the electromagnetic actuator of Patent Document 1, the lock pin and the restriction pin vibrate in the same direction due to vibration of the internal combustion engine, etc., so that the taper surface of the lock pin and the ball are separated from each other and the restriction pin may be unlocked. As a result, there is a problem that adjustment of the valve lift amount becomes impossible when the regulation pin operates at an improper timing and comes into contact with a rotating part such as a slider and is damaged.
If the load for pressing the lock pin against the ball is increased, it is necessary to increase the electromagnetic force for pulling out the lock pin accordingly, which increases the size of the electromagnetic actuator. Even if the pressing force of the lock pin is increased, the lock pin and the restriction pin vibrate in the same direction, so there is still a possibility that the restriction pin is unlocked.

  The present invention was created in view of the above points, and an object of the present invention is to prevent the lock of the restriction pin from being released due to vibration or the like in an electromagnetic actuator applied to a valve lift adjustment device of an internal combustion engine. It is to provide an electromagnetic actuator.

  The present invention is applied to a valve lift adjustment device for an internal combustion engine, and switches between a locked state in which a restriction pin is locked and a free state in which the restriction pin is operable by an electromagnetic force generated by energization of a coil. In the state, in the electromagnetic actuator that operates the restriction pin by a spring force, a latch member that locks the restriction pin is provided so as to be able to reciprocate in a direction orthogonal to the axis of the restriction pin.

Since the movable directions of the latch member and the restriction pin are orthogonal to each other, it is possible to prevent the restriction pin from being unlocked due to vibration of the internal combustion engine or the like. Therefore, it is possible to prevent the restriction pin from being damaged due to the restriction pin operating at an inappropriate timing. Therefore, the reliability of the valve lift adjustment device can be improved.
Further, the electromagnetic driving force can be reduced by electromagnetically driving the latch member in the direction orthogonal to the regulating pin as compared with the configuration in which the regulating pin is directly held by the electromagnetic force. Therefore, the physique of the electromagnetic actuator can be reduced.

  Furthermore, in the electromagnetic actuator of the present invention applied to the valve lift adjusting device, the regulating pin is pushed back by the torque of the camshaft when the tip of the regulating pin is separated from the engagement groove. This pushing back force is sufficiently large with respect to the driving force by which the electromagnetic actuator advances the restriction pin. Therefore, as a driving force for advancing the restriction pin, a relatively large spring load is always applied to the restriction pin without generating an electromagnetic force only at the time of operation, and when not operated, the restriction pin is locked by a latch member. Thus, the configuration of the electromagnetic actuator can be simplified.

It is a figure when it starts to shift from a small lift state to a large lift state in a valve lift adjustment device to which an electromagnetic actuator according to a first embodiment of the present invention is applied. It is the II-II sectional view taken on the line of FIG. It is a figure in the middle of changing from a small lift state to a large lift state in a valve lift adjustment device to which an electromagnetic actuator by a 1st embodiment of the present invention is applied. It is the IV-IV sectional view taken on the line of FIG. It is a figure when it starts to shift from a large lift state to a small lift state in the valve lift adjusting device to which the electromagnetic actuator according to the first embodiment of the present invention is applied. FIG. 6 is a sectional view taken along line VI-VI in FIG. 5. It is sectional drawing which shows the locked state of the electromagnetic actuator by 1st Embodiment of this invention. It is the VIII-VIII sectional view taken on the line of FIG. It is sectional drawing which shows a state (free state) when it supplies with electricity from the locked state of FIG. It is sectional drawing which shows a state when electricity supply is stopped from the state of FIG. It is a figure which shows the relationship between the latch plate and latch groove in a free state. It is a figure which shows the relationship between a latch plate when shifting to a locked state from a free state and a latch groove | channel. It is a figure which shows the relationship between a latch plate when the transfer to a locked state is completed. It is a figure when it starts to shift from a small lift state to a large lift state in a valve lift adjustment device to which an electromagnetic actuator according to a second embodiment of the present invention is applied. It is a figure when it starts to shift from a large lift state to a small lift state in a valve lift adjusting device to which an electromagnetic actuator according to a second embodiment of the present invention is applied. It is sectional drawing which shows the neutral mode of the electromagnetic actuator by 2nd Embodiment of this invention. (A) It is the XVII-XVII sectional view taken on the line of FIG. (B) It is sectional drawing equivalent to (a) in a 1st operation mode. (C) It is sectional drawing equivalent to (a) in 2nd operation mode.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The electromagnetic actuator according to the first embodiment of the present invention is applied to a valve lift adjusting device that adjusts the lift amount of an intake valve of an internal combustion engine.

First, the valve lift adjusting device will be described with reference to FIGS. In the following description, “FIG. 1 etc.” refers to FIGS. 1, 3 and 5, and “FIG. 2 etc.” refers to FIGS. 2, 4 and 6.
As shown in FIGS. 1 to 6, the valve lift adjusting device 101 is linked via rollers 31 and 32 and swing arms 33 and 34 by a cam integrally provided on a slider 21 that rotates together with the camshaft 11. The lift amount of the intake valves 91 and 92 is adjusted.

The camshaft 11 rotates in a fixed direction in conjunction with a crankshaft (not shown). This rotational direction corresponds to the counterclockwise direction when the camshaft 11 is viewed from the left side in FIG.
As shown in FIG. 2 and the like, the camshaft 11 has spline external teeth formed on the outer surface of the portion where the slider 21 is fitted. In addition, illustration of a spline external tooth is abbreviate | omitted in FIG.
The cylindrical slider 21 is provided so as to be able to move relative to the camshaft 11 in the axial direction while rotating together with the camshaft 11 by engaging the spline inner teeth formed on the inner surface with the spline outer teeth of the camshaft 11. Yes. That is, the slider 21 is provided so as to be capable of reciprocating in the axial direction between two slider limiters 12 and 22 fixed to the camshaft 11 in a bowl shape.

Two sets of switching portions 13 and 23, small lift cams 18 and 28, and large lift cams 19 and 29 are integrally provided at both ends of the slider 21. The switching units 13 and 23 switch the position of the slider 21 in the axial direction with respect to the camshaft 11.
Hereinafter, the left switching unit in FIG. 1 is referred to as a first switching unit 13, and the right switching unit in FIG. 1 is referred to as a second switching unit 23. Since these two sets of configurations are basically the same, the configuration of the first switching unit 13, the first small lift cam 18 and the first large lift cam 19 will be described as a representative.

The first switching part 13 is formed with a first engagement groove 14 including a front part 15, a transition part 16, and a rear part 17.
The front stage part 15 and the rear stage part 17 extend in directions orthogonal to the axis at different positions in the axial direction. Further, as shown in FIG. 2, the depth of the groove becomes shallower toward the front in the rotational direction as shown in FIG. 2, and the depth of the groove becomes shallower toward the rear in the rotational direction as shown in FIG. Become.
The transition part 16 connects the front stage part 15 and the rear stage part 17 while tilting so that the front in the rotational direction approaches the front stage part 15 and the rear in the rotational direction approaches the rear stage part 17 with respect to the direction orthogonal to the axis. ing.

Here, two electromagnetic actuators 401 and 402 corresponding to the first switching unit 13 and the second switching unit 23 are applied to the valve lift adjusting device 101.
The electromagnetic actuator 401 corresponding to the first switching unit 13 advances the restriction pin 601 in synchronization with the rotation timing of the camshaft 11 and engages the first engagement groove 14. As a result, the slider 21 moves toward the slider limiter 12 as the camshaft 11 rotates. On the other hand, the electromagnetic actuator 402 corresponding to the second switching unit 23 advances the regulation pin 602 in synchronization with the rotation timing of the camshaft 11 and engages the second engagement groove 24. As a result, the slider 21 moves to the slider limiter 22 side as the camshaft 11 rotates. This detailed operation will be described later.

  The first small lift cam 18 and the first large lift cam 19 are provided adjacent to each other near the center of the slider 21 in the axial direction with respect to the first switching portion 13. As shown in FIG. 2 and the like, the first small lift cam 18 and the first large lift cam 19 are eccentric to the outside with respect to the reference circle in one direction of rotation. Further, the first large lift cam 19 is formed so that the amount of eccentricity from the reference circle is larger than that of the first small lift cam 18.

  With respect to the first switching unit 13 described above, the second switching unit 23 is arranged symmetrically in FIG. The second small lift cam 28 and the second large lift cam 29 are provided adjacent to each other near the center of the slider 21 in the axial direction with respect to the second switching portion 23. The second small lift cam 28 and the second large lift cam 29 are offset in the same direction in the axial direction with respect to the first small lift cam 18 and the first large lift cam 19 and are eccentric in the rotational direction. The portions are arranged in a direction shifted by about 180 °.

The rollers 31 and 32 and the swing arms 33 and 34 correspond to the two sets of small lift cams 18 and 28 and the large lift cams 19 and 29, respectively. The rotational movement of the camshaft 11 is reciprocated by the intake valves 91 and 92. Convert to
The rollers 31 and 32 are interposed between the small lift cams 18 and 28 and the large lift cams 19 and 29 and the central portions of the swing arms 33 and 34.

  The swing arms 33 and 34 have one end abutting against the lash adjusters 35 and 36 and the other end abutting against the intake valves 91 and 92. The swing arms 33, 34 swing with the contact portions with the lash adjusters 35, 36 as fulcrums so that the other ends of the arms approach or separate from the intake valves 91, 92. The lash adjuster 35 corresponding to the swing arm 33 is shown in FIG. 2 and the like, and the lash adjuster 36 corresponding to the swing arm 34 is not shown.

Next, the operation of the valve lift adjusting device 101 will be described with reference to FIGS.
As shown in FIGS. 1 and 2, when the slider 21 is on the slider limiter 22 side, the roller 31 contacts the outer peripheral surface of the eccentric portion of the small lift cam 18 and pushes down the swing arm 33. As a result, the intake valve 91 of the cylinder head 90 is opened by a relatively small lift amount L1. Further, the roller 32 abuts on the outer peripheral surface of the eccentric portion of the small lift cam 28 at a phase shifted by about 180 ° from the roller 31 and pushes down the swing arm 34. As a result, the intake valve 92 is opened by the lift amount L1.
Hereinafter, this state of the valve lift adjusting device 101 is referred to as a “small lift state”. In contrast, a state in which the roller 31 is in contact with the outer peripheral surface of the eccentric portion of the large lift cam 19 is referred to as a “large lift state”.

In the small lift state, the restriction pin 601 of the electromagnetic actuator 401 is located immediately above the front stage portion 15 of the first engagement groove 14. Therefore, when shifting from the small lift state to the large lift state, the electromagnetic actuator 401 advances the restriction pin 601 at the timing when the rotational position of the camshaft 11 becomes the position shown in FIGS. Engage with the groove 14.
When the slider 21 rotates together with the camshaft 11 with the restriction pin 601 fitted in the first engagement groove 14, the position of the groove into which the restriction pin 601 is fitted moves from the front stage part 15 to the rear stage part 17 via the transition part 16. At the same time, the slider 21 moves toward the slider limiter 12 as indicated by an arrow A1 in FIG.

The position P1 of the cams 18 and 19 when the slider 21 rotates 90 ° from the position P0 shown in FIGS. 1 and 2 is shown by solid lines in FIGS. Further, the positions P2 and P3 of the cams 18 and 19 when the slider 21 is rotated 180 ° and 270 ° from the position P0 are indicated by broken lines in FIG. In the rotation range from the position P1 to the position P3, since the roller 31 is in contact with the outer peripheral surface of the reference circular portion of the cams 18 and 19, the intake valves 91 and 92 are kept closed.
Further, at the rotational position past the position P 3, the depth of the groove of the rear stage portion 17 becomes shallow, and the bottom wall of the rear stage portion 17 pushes back the restriction pin 601 of the electromagnetic actuator 401.

  Thereafter, as shown in FIGS. 5 and 6, at the position P <b> 4 where the slider 21 has rotated 360 ° from the position P <b> 0, the roller 31 comes into contact with the outer peripheral surface of the eccentric portion of the large lift cam 19 and pushes down the swing arm 33. . That is, the valve lift adjusting device 101 is in a large lift state. As a result, the intake valve 91 of the cylinder head 90 is opened by a relatively large lift amount L2. Further, the roller 32 abuts on the outer peripheral surface of the eccentric portion of the large lift cam 29 at a phase shifted by about 180 ° from the roller 31 and pushes down the swing arm 34. As a result, the intake valve 92 is opened by the lift amount L2.

In the large lift state, the restriction pin 602 of the electromagnetic actuator 402 is located immediately above the front portion 25 of the second engagement groove 24. Therefore, when shifting from the large lift state to the small lift state, the electromagnetic actuator 402 moves the restriction pin 602 forward at the timing when the rotational position of the camshaft 11 reaches the position shown in FIGS. Engage with the groove 24.
When the slider 21 rotates together with the camshaft 11 in a state where the restriction pin 602 is fitted in the second engagement groove 24, the position of the groove in which the restriction pin 602 is fitted is changed from the front stage part 25 to the rear stage part 27 via the transition part 26. At the same time, the slider 21 moves toward the slider limiter 22 as indicated by an arrow A2 in FIG.

As described above, the valve lift adjusting device 101 controls the operation of the electromagnetic actuators 401 and 402 in synchronization with the rotation timing of the camshaft 11, thereby changing the lift amount of the intake valves 91 and 92 to the lift amount L1 and the lift amount. It is possible to switch to either L2.
Specifically, the operating conditions can be appropriately improved by adjusting the valve lift amount according to the rotational speed and load of the internal combustion engine.

Next, the detailed structure of the electromagnetic actuator which is the principal part of this invention is demonstrated with reference to FIGS. In the following description, of the two electromagnetic actuators 401 and 402, the electromagnetic actuator 401 on the first switching unit 13 side will be described as a representative.
As shown in FIGS. 7 to 10, the electromagnetic actuator 401 includes an electromagnetic driving unit 501, a latch plate 55, a regulation pin 601, a sleeve 70, a pin spring 74, and the like.

The electromagnetic drive unit 501 includes a coil 42, a first stator 43, a second stator 44, a yoke 46, a plunger 51, a return spring 53, and the like.
The coil 42 is energized via the connector 48 to generate an electromagnetic force that attracts the plunger 51.

The 1st stator 43 and the 2nd stator 44 are formed with a magnetic body, and respectively cover the axial direction edge part of coil 42, and a part of diameter direction. A gap 45 is formed between the first stator 43 and the second stator 44.
The first stator 43 and the second stator 44 constitute a transmission path of the magnetic flux Φ generated by the coil 42 by energization. At this time, by forming the gap 45, the magnetic flux Φ flows from the first stator 43 to the second stator 44 via the plunger 51.

The yoke 46 is formed of a magnetic material in a cylindrical shape and covers the radially outward direction of the coil 42. The yoke 46, together with the first stator 43 and the second stator 44, constitutes a transmission path for the magnetic flux Φ generated by the coil 42 by energization.
The first stator 43 is joined to the opening 461 on the sleeve 70 side of the yoke 46, and the second stator 44 is joined to the opening 462 on the opposite side of the sleeve 70.

Plunger 51 is formed of a magnetic material, and outer wall 511 slides along the inner walls of first stator 43 and second stator 44, and reciprocates between the position shown in FIG. 7 and the position shown in FIG. When the latch plate 55 is connected to a connection hole 512 formed on the end surface of the plunger 51 on the regulation pin 601 side, the plunger 51 and the latch plate 55 move together.
Hereinafter, the movement of the plunger 51 from the position shown in FIG. 9 to the position shown in FIG. 7 on the basis of the positional relationship between the plunger 51 and the restriction pin 601 is referred to as “approach”, and from the position shown in FIG. The movement of the plunger 51 to the position is referred to as “retraction”. The return spring 53 is sandwiched between the end surface of the plunger 51 on the side opposite to the latch plate 55 and the hole bottom surface 441 of the second stator 44, and biases the plunger 51 in the approaching direction.
In addition, the position shown in FIG. 10 is a position where the plunger 51 is moved in the approaching direction by an amount of play with respect to the position shown in FIG. This will be described in detail later.

  As shown in FIGS. 11 to 13A and 13B, the latch plate 55 as a “latch member” has a rectangular parallelepiped shape with a connecting shaft 553 protruding at one end in the longitudinal direction. The latch plate 55 is accommodated in the accommodation chamber 712 of the sleeve 70 in a state where the connection shaft 553 is fitted in the connection hole 512 of the plunger 51. The plate thickness of the latch plate 55 is slightly smaller than the groove width of the latch groove 611 formed in the shaft body 61 of the restriction pin 601.

  The latch plate 55 is formed with a composite hole 56 including an insertion hole 560 and a lock portion 561. The insertion hole 560 has an inner diameter larger than the outer diameter of the shaft main body 61 of the restriction pin 601, and the shaft main body 61 can be inserted therethrough. The lock part 561 is recessed in the inner wall in the retracting direction of the latch plate 55 in the insertion hole 560. The lock portion 561 has an inner diameter equivalent to the outer diameter of the lock shaft 62 of the regulation pin 601 and can be fitted to the lock shaft 62 as shown in FIG.

  The introduction portion 551 of the latch plate 55 is a portion that first contacts the inner wall of the latch groove 611 when the latch plate 55 approaches the restriction pin 601 from the electromagnetic drive portion 501 side and engages with the latch groove 611. The steady portion 512 is a portion that abuts against the inner wall of the latch groove 611 when the lock portion 561 is fitted to the lock shaft 62. In the present embodiment, the introduction portion 551 is inclined inward from the surface of the latch plate 55. In other words, the introduction portion 551 is formed with a slope with a constant gradient so that the plate thickness gradually increases to the boundary with the steady portion 552.

Returning to FIGS. 7 to 10, the restriction pin 60 is coaxially formed on the central axis O in the order of the shaft main body 61, the flange portion 63, and the distal end portion 64 from the base end side.
A latch groove 611 as a “receiving portion” is formed in a circumferential direction in a part of the shaft body 61 in the axial direction. The outer wall of the lock shaft 62 forms the bottom of the latch groove 611.
The shaft body 61 is supported by the bearing portion 713 of the sleeve 70 on the proximal end side with respect to the lock shaft 62, and is supported by the bearing portion 714 of the sleeve 70 on the distal end side of the lock shaft 62.

The collar portion 63 can reciprocate within the accommodation hole 721 of the sleeve 70. The step surface between the flange 63 and the shaft body 61 constitutes a spring seat surface 631 that supports the front end of the pin spring 74. Further, the step surface between the flange 63 and the tip 64 constitutes a stopper surface 633 that abuts against the end surface of the bush 73 when the restriction pin 601 moves forward.
The distal end portion 64 is supported by the bush 73, and the outer wall 641 of the distal end portion 64 slides on the inner wall of the bush 73. In the present embodiment, the last retracted position of the distal end surface 643 protrudes from the end surface 723 of the sleeve 70 by about several millimeters. Further, the tip end face 643 further protrudes several tens of millimeters from the end face 723 of the sleeve 70 during advancement, and engages with the engagement groove 14 formed in the switching portion 13 of the valve lift adjusting device 101.

  As shown in FIG. 11 to FIG. 13C, the distal end surface 643 at the most retracted position of the regulation pin 601 is installed between the outer peripheral surface of the switching unit 13 of the valve lift adjusting device 101 via a clearance CL. Is done. As a result, at the last retracted position of the restriction pin 601 shown in FIG.

The sleeve 70 includes a joint portion 71 and a pin housing portion 72 whose axial directions are orthogonal to each other.
The joint portion 71 includes a flange portion 711 that is joined to the opening 461 on the first stator 43 side of the yoke 46, a housing chamber 712 that houses the latch plate 55, and a set of bearing portions 713 that support the shaft body 61 of the restriction pin 601. 714, etc. The storage chamber 712 corresponds to the shape of the latch plate 55 and has a rectangular cross section.
The pin housing part 72 has a housing hole 721 for housing the flange 63 of the regulation pin 601. A bush 73 is fitted into the opening to the end surface 723 of the accommodation hole 721. The inner wall of the bush 73 is coaxially formed on the central axis O of the accommodation hole 721, and the outer wall 641 of the distal end portion 64 of the regulation pin 601 slides.

  The pin spring 74 is externally inserted into the shaft body 61 of the restriction pin 60, and both ends are supported between the bottom surface of the accommodation hole 721 and the spring seat surface 631 of the restriction pin 601. The pin spring 74 biases the restriction pin 601 in the forward direction.

Next, the operation of the electromagnetic actuator 401 having the above configuration will be described.
As shown in FIG. 7, when the coil 42 is not energized, the plunger 51 approaches due to the urging force of the return spring 53, so that the latch plate 55 fits into the latch groove 611 and locks the restriction pin 601 inoperable. This state is called “locked state”.

As shown in FIG. 9, when the coil 42 is energized, the plunger 51 is retracted by electromagnetic force, and the fitting between the latch plate 55 and the latch groove 611 is released. This state is called “free state”.
In the free state, the restricting pin 601 moves forward by the urging force of the pin spring 74, whereby the tip end portion 64 of the restricting pin 601 protrudes from the end surface 723 of the sleeve 70 and engages with the engaging groove 14 of the valve lift adjusting device 101. . Then, the slider 21 is moved to a predetermined position by the rotation of the camshaft 11, and the valve lift amount is switched. Subsequently, the distal end portion 64 of the restriction pin 601 is pushed back by the rotation of the switching portion 13 and the engagement with the engagement groove 14 is released.

In the present embodiment, the energization of the coil 42 is stopped when the regulation pin 601 moves forward. Then, as shown in FIG. 10, the latch plate 55 is moved in the approaching direction by a play amount corresponding to the difference between the radius of the insertion hole 560 and the radius of the shaft body 61 by the urging force of the return spring 53. The inner diameter of 560 contacts the outer diameter of the shaft body 61. In this manner, the energization time can be minimized by stopping energization of the coil 42 as soon as the latch plate 55 and the latch groove 611 are disengaged.
Therefore, in the state shown in FIG. 11, strictly speaking, the shaft body 61 is eccentric with respect to the insertion hole 560. However, in FIG. 11, the shaft main body 61 is shown concentrically with respect to the insertion hole 560 for easy viewing.

  As shown in FIG. 11, when the distal end portion 64 is pushed back in a free state, the restriction pin 601 moves backward with the shaft body 61 passing through the insertion hole 560 of the latch plate 55. At this time, the front end surface 643 of the regulation pin 601 is in a state of projecting by a length corresponding to the clearance CL with the outer peripheral surface of the switching unit 13 with respect to the last retracted position illustrated by a two-dot chain line. Correspondingly, the position of the latch groove 611 of the regulation pin 601 is slightly shifted forward with respect to the latch plate 55.

  Thereafter, as shown in FIG. 12, as the latch plate 55 approaches due to the urging force of the return spring 53, the transition from the free state to the locked state is started. At this time, the introduction portion 551 of the latch plate 55 first contacts the inner wall of the latch groove 611. The introduction portion 551 smoothly enters the inner wall of the latch groove 611 because the end portion is thin. In addition, since the plate thickness of the introduction portion 551 gradually increases from the end portion along the slope, the wedge effect on the latch groove 611 due to the advancement of the latch plate 55 works, and the restriction pin 601 is gradually pulled in the backward direction. . Along with this, the front end surface 643 of the regulation pin 601 is separated from the outer peripheral surface of the switching unit 13, and the amount of protrusion gradually decreases.

  As shown in FIG. 13, when the latch plate 55 further approaches, the lock portion 561 of the composite hole 56 is fitted to the lock shaft 62, thereby completing the transition to the locked state. At this time, the restriction pin 601 is pulled to the last retracted position of the tip surface 643.

(effect)
The effect of the electromagnetic actuator 401 of this embodiment will be described.
(1) In the electromagnetic actuator 401 of the present embodiment, since the movable directions of the latch plate 55 and the restriction pin 601 are orthogonal to each other, it is possible to prevent the restriction pin 601 from being unlocked due to vibration of the internal combustion engine or the like. Can do. Therefore, it is possible to prevent the restriction pin 601 from being damaged due to the restriction pin 601 operating at an inappropriate timing. Therefore, the reliability of the valve lift adjusting device 101 can be improved.

  (2) The electromagnetic actuator 401 of the present embodiment can reduce the electromagnetic driving force by electromagnetically driving the latch plate 55 in the direction orthogonal to the regulating pin 601 as compared with a configuration in which the regulating pin is directly held by electromagnetic force. it can. That is, when the restriction pin is directly held by electromagnetic force, an electromagnetic force of 100% or more of the compression load of the pin spring is required. On the other hand, when the latch plate 55 is moved in a direction orthogonal to the restriction pin 601, an electromagnetic force of, for example, about 30%, which is a coefficient of static friction between irons, can be obtained with respect to the compression load of the pin spring. Therefore, the physique of the electromagnetic drive part 501 can be made small.

  (3) By specifically configuring the “latch member” and the “receiving portion” of the restriction pin 601 with the latch plate 55 and the circumferential latch groove 611, it is advantageous for securing an overlapping area in the locked state. . Further, since the regulation pin 601 may rotate, a means for preventing the regulation pin 601 from rotating is unnecessary, and the rotation of the regulation pin 601 is positively allowed to wear the tip surface 643 at one location. Concentration can be avoided.

  (4) The latch plate 55 is formed so that the plate thickness gradually increases from the introduction portion 551 to the steady portion 552. Thereby, when shifting from the free state to the locked state, the restricting pin 601 can be pulled to the rearmost position by the wedge effect. Therefore, when the distal end portion 64 of the regulation pin 601 is separated from the engagement groove 14, the regulation pin 601 is moved from the position pushed back by the rotation of the switching portion 13 until the distal end surface 643 of the regulation pin 601 reaches the last retracted position. The leading end surface 643 can be reliably pulled away from the outer peripheral surface of the switching unit 13. Therefore, it is possible to prevent the distal end surface 643 of the regulation pin 601 from being worn by continuous contact with the switching unit 13 that rotates constantly.

  (5) In the electromagnetic actuator 401 of the present invention applied to the valve lift adjusting device 101, the regulating pin 601 is pushed back by the torque of the camshaft 11 when the distal end portion 64 of the regulating pin 601 is separated from the engagement groove 14. This pushing back force is sufficiently large with respect to the driving force for the electromagnetic actuator 401 to advance the regulating pin 601. Therefore, a relatively large spring load is always applied to the restriction pin as a driving force for moving the restriction pin 601 forward, even when electromagnetic force is not generated only during operation, and the restriction pin 601 is locked by the latch plate 55 when not activated. With this configuration, the configuration of the electromagnetic actuator can be simplified.

(Second Embodiment)
Next, the electromagnetic actuator of 2nd Embodiment of this invention is demonstrated with reference to FIGS. In the following description of the embodiment, the same reference numerals are given to substantially the same components as those in the first embodiment, and the description will be omitted.
As shown in FIGS. 14 and 15, the valve lift adjusting device 103 to which the electromagnetic actuator 403 of the second embodiment is applied is different from the valve lift adjusting device 101 described in the first embodiment with two switching units 13, Instead of 23, one integrated switching unit 20 is provided.

  In the integrated switching part 20, the rear stage part 17 of the first engagement groove 14 and the rear stage part 27 of the second engagement groove 14 are overlapped, and are engaged so as to exhibit a “Y” in the viewing direction of FIGS. Grooves are formed. Therefore, the front step portion 15 of the first engagement groove 14 and the front step portion 25 of the second engagement groove 14 are arranged at positions close to each other. Corresponding to this configuration, the valve lift adjusting device 103 is applied with an electromagnetic actuator 403 provided with two regulating pins 603 and 604 arranged in one housing.

The electromagnetic actuator 403 has a function of switching the following three modes.
(A) Neutral mode in which both the first restriction pin 603 and the second restriction pin 604 are held at the last retracted position.
(B) A first operation mode in which the first restriction pin 603 is advanced and the second restriction pin 604 is held at the last retracted position.
(C) A second operation mode in which the second restriction pin 604 is advanced and the first restriction pin 603 is held at the last retracted position.

Next, the configuration of the electromagnetic actuator 403 according to the second embodiment will be described with reference to FIGS. 16 and 17, particularly focusing on differences from the first embodiment.
As shown in FIG. 16, the electromagnetic actuator 403 is different from the first embodiment in the configuration of the electromagnetic drive unit 503, the latch plate 57, and the sleeve 75. On the other hand, the individual configurations of the regulation pins 603 and 604 are substantially the same as the configuration of the regulation pin 601 of the first embodiment.

  In the electromagnetic drive unit 503, a ring-shaped permanent magnet 52 and two return springs 541 and 542 are accommodated inside the first stator 49 and the second stator 44 in order to switch between the three modes. The permanent magnet 52 is magnetized with magnetic poles at both ends in the axial direction. In the present embodiment, the first stator 49 side is the S pole and the second stator 44 side is the N pole. The first return spring 541 has one end in contact with the hole bottom surface 491 of the first stator 49 and the other end in contact with the shaft end surface of the permanent magnet 52 on the S pole side. The second return spring 542 has one end in contact with the hole bottom surface 441 of the second stator 44 and the other end in contact with the shaft end surface on the N pole side of the permanent magnet 52.

  When the coil 42 is not energized, the permanent magnet 52 is maintained at the neutral position by the balance of the loads of the return springs 541 and 542. On the other hand, the permanent magnet 52 is attracted in either direction against the urging force of the return springs 541 and 542 depending on the direction of the magnetic field generated when the coil 42 is energized.

The latch plate 57 as a “latch member” is joined to the permanent magnet 52 in the electromagnetic drive unit 503 through the fitting hole 492 of the first stator 49 at the end on the electromagnetic drive unit 503 side. Thereby, the latch plate 57 moves integrally with the permanent magnet 52.
As shown in FIG. 17, the latch plate 57 is formed with a composite hole 58 including an insertion hole 580 and two lock portions 581 and 582. The shaft body 61 of the restriction pins 603 and 604 can be inserted into the insertion hole 580. The first lock portion 581 is recessed in the inner wall in the approaching direction of the latch plate 57 in the insertion hole 580, and the second lock portion 582 is recessed in the inner wall in the retracting direction of the latch plate 57 in the insertion hole 580. The lock portions 581 and 582 can be fitted to the lock shaft 62 of the regulation pins 603 and 604.
The latch plate 57 may be formed with the introduction portion 551 similarly to the latch plate 55 of the first embodiment.

  In the sleeve 75, the joint portion 76 and the pin housing portion 77 are more than the joint portion 71 and the pin housing portion 72 of the first embodiment so that the two regulating pins 603 and 604 are accommodated around the central axes O1 and O2, respectively. Is also formed large. The joint portion 76 includes a flange portion 761, a storage chamber 762, two sets of bearing portions 763 and 764, and the like, similarly to the joint portion 71 of the first embodiment. The pin accommodating portion 77 has two accommodating holes 771, and a bush 73 is fitted into an opening portion to the end surface 773 of the accommodating hole 771.

Next, the operation of the electromagnetic actuator 403 of the second embodiment will be described with reference to FIGS.
As shown in FIG. 16 and FIG. 17A, the permanent magnet 52 is maintained in the neutral position by the balance of the loads of the return springs 541 and 542 when not energized. In this state, both the first lock portion 581 and the second lock portion 582 of the composite hole 58 are fitted to the lock shafts 62 of the first restriction pin 603 and the second restriction pin 604, and the first restriction pin 603 and the second restriction pin 604 are fitted. The pin 604 is held at the last retracted position. In this way, the “neutral mode” is realized.

When the magnetic field is generated in such a direction that the permanent magnet 52 is attracted toward the first stator 49 by energizing the coil 42, as shown in FIG. Move in the direction of operation. At this time, the first restriction pin 603 is in a free state in which the shaft body 61 can be inserted through the insertion hole 580 of the composite hole 58, and moves forward by the urging force of the pin spring 74. On the other hand, the second restriction pin 604 is in a locked state in which the lock shaft 62 is fitted to the second lock portion 582 and is held at the last retracted position. Thus, the “first operation mode” is realized.
After that, when energization is stopped and the front end portion 64 of the first restriction pin 603 is pushed back by the rotation of the integrated switching portion 20, the permanent magnet 52 and the latch plate 57 are moved to the neutral position by the urging force of the first return spring 541. This will return to the “neutral mode”.

When energizing the coil 42 generates a magnetic field that attracts the permanent magnet 52 toward the second stator 44, as shown in FIG. 17C, the latch plate 57 is in the second direction in the right direction in the figure. Move in the direction of operation. At this time, the second restriction pin 604 is in a free state in which the shaft body 61 can be inserted through the insertion hole 580 of the composite hole 58, and moves forward by the urging force of the pin spring 74. On the other hand, the first restriction pin 603 is in a locked state in which the lock shaft 62 is fitted to the first lock portion 581 and is held at the last retracted position. Thus, the “second operation mode” is realized.
After that, when the energization is stopped and the distal end portion 64 of the second restriction pin 604 is pushed back by the rotation of the integrated switching portion 20, the permanent magnet 52 and the latch plate 57 are moved to the neutral position by the urging force of the second return spring 542. This will return to the “neutral mode”.

  As described above, the electromagnetic actuator 403 of the second embodiment can switch the operation of the two restriction pins 603 and 604 with one electromagnetic actuator 403 in addition to the same effects as the first embodiment. And the number of wirings can be reduced. Moreover, the installation space for the electromagnetic actuator can be integrated into one place.

(Other embodiments)
(A) Instead of the latch plate 55 of the first embodiment, a latch pin is used as a “latch member”, and a hole perpendicular to the shaft into which the latch pin can be fitted is formed in the shaft body of the restriction pin as a “receiving portion”. You may form as. Preferably, the same effect as the introduction part 511 of 1st Embodiment can be show | played by making the front-end | tip part of a pin into a taper taper shape.
In this case, since the positions of the latch pin and the hole are shifted when the regulation pin rotates, it is necessary to provide a rotation prevention means for the regulation pin.

  (A) In the first embodiment, the electromagnetic drive unit 501 is configured to be in a locked state when not energized and in a free state when energized. Conversely, the electromagnetic drive unit may be configured to be in a free state when not energized and in a locked state when energized. For example, a lock portion that sinks into the inner wall in the approaching direction of the latch plate in the insertion hole can be formed so as to be in a free state at the approaching position of the latch plate and to be in a locked state at the retracted position of the latch plate.

(C) The introduction portion 551 in the first embodiment is formed with a slope having a constant gradient up to the boundary with the steady portion 552. In addition, the “introducing part” and the “steady part” may be configured by combining a plurality of slopes having different slopes, and a part of the slopes has a zero slope, that is, a plane parallel to the movement axis of the latch member. May be included. Alternatively, the “introducing part” may be configured with a surface with a zero gradient, which is thinner than the “steady part”, and the “introducing part” and the “steady part” may be connected by an inclined surface.
In any of these forms, a configuration in which “the plate thickness is gradually increased from the introduction portion to the steady portion” can be realized.

(D) In the first embodiment, the front end surface 643 of the regulation pin 601 protrudes from the end surface 723 of the sleeve 70 at the most retracted position. On the other hand, the front end surface 643 of the regulation pin 601 may be provided so as to be the same surface as the end surface 723 of the sleeve 70 or to be recessed from the end surface 723 at the last retracted position.
(E) In the first embodiment, energization of the coil 42 is stopped as soon as the engagement between the latch plate 55 and the latch groove 611 is released during the transition from the locked state to the free state. On the other hand, the energization may be continued even after the engagement between the latch plate 55 and the latch groove 611 is released, and the energization may be released after the distal end surface 643 is pushed back by the outer peripheral surface of the switching unit 13. . Accordingly, in the state shown in FIG. 11, the shaft main body 61 maintains concentricity with respect to the insertion hole 560, so that the outer wall of the shaft main body 61 can be prevented from being worn.

(F) The valve lift adjusting device is not limited to the intake valve, and may adjust the lift amount of the exhaust valve.
(G) The configuration of the cam lift, slider, etc. of the valve lift adjustment device is not limited to that illustrated in the above embodiment, and any configuration can be used as long as it can be switched by forward and backward movement of the restriction pin of the electromagnetic actuator. May be.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

101, 103 ... Valve lift adjusting device,
11 ... camshaft, 14, 24 ... engagement groove,
21 ... Slider,
401, 402, 403 ... electromagnetic actuator 501, 503 ... electromagnetic drive unit, 53 ... return spring,
55, 57 ... latch plate (latch member),
601, 602, 603, 604 ... restriction pin,
61 ... shaft main body, 611 ... latch groove (receiving part),
64 ・ ・ ・ the tip,
74 ・ ・ ・ Pin spring,
91, 92 ... Intake valves.

Claims (3)

The camshaft is applied to a valve lift adjusting device (101, 103) for adjusting the lift amount of an intake valve (91, 92) or an exhaust valve of an internal combustion engine, and rotates with the camshaft (11) of the valve lift adjusting device. When the front end portion (64) of the restriction pin (601, 602, 603, 604) is engaged with the engagement groove (14, 24) formed in the slider (21) that is relatively movable in the axial direction, the restriction An electromagnetic actuator (401, 402, 403) in which the restriction pin is pushed back by the torque of the camshaft when the pin is advanced and the tip of the restriction pin is separated from the engagement groove,
The restriction pin provided to be able to move forward with respect to the engagement groove;
It is provided so as to be able to reciprocate in a direction perpendicular to the axis of the restriction pin, and when it approaches the restriction pin, it fits into a receiving portion (611) formed on the shaft main body (61) of the restriction pin, and the restriction pin is Latch members (55, 57) that lock inoperably;
The latch member is driven by an electromagnetic force generated by energization and a biasing force of a return spring (53, 541, 542), and the latch member engages with the receiving portion, and the latch member and the receiving portion Electromagnetic drive units (501, 502) capable of switching the free state to release the fitting with
A pin spring (74) for urging the regulating pin in the forward direction;
An electromagnetic actuator comprising: The receiving portion of the restriction pin is a latch groove (611) formed in the circumferential direction of the shaft body,
The latch member is formed in a plate shape extending in a direction orthogonal to the axis of the restriction pin, and the insertion hole (560, 580) through which the shaft body is inserted in the free state, and the latch member in the insertion hole A lock portion (561, 581, 582) that fits into a lock shaft (62) having the groove bottom of the latch groove as an outer wall in the locked state. The electromagnetic actuator according to claim 1.   The plate-like latch member is fitted into the latch groove when the transition to the locked state is completed from the introduction portion (551) that first fits into the latch groove when the free state shifts to the locked state. The electromagnetic actuator according to claim 2, wherein the plate thickness is gradually increased up to the stationary portion (552) to be joined.

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