JP2008298057A - Valve lift actuator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a valve lift actuator having high durability. <P>SOLUTION: A rotation-linear motion converting mechanism 30 includes a linear motion shaft 34 to make linear motion and a control shaft 12 for changing the amount of valve lift screwed with each other in a rotor 31. An oil seal 40 is arranged at the boundary between a first accommodation chamber 22 where the first end 31a of the rotor 31 is opened and a second accommodation chamber 23 to accommodate the second end 31b on the closed side of the rotor 31 and a motor stator 52. In this constitution, the rotor 31 has an outside communication hole 100 to be in communication with a supply hole 96 provided outside the rotor 31, an inside communication hole 116 to be in communication with inside the rotor 31 while it is arranged apart from the outside communication hole 100 in the axial direction of the rotor 31 directed from the first end 31a to the second end 31b, and a junction hole 114 to relay between the outside communication hole 100 and the inside communication hole 116. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a valve lift control device that controls a valve lift amount of a control target valve that is at least one of an intake valve and an exhaust valve of an internal combustion engine, and a valve that linearly drives a control shaft for changing the valve lift amount. The present invention relates to a lift actuator.

  2. Description of the Related Art Conventionally, there has been known a valve lift actuator in which a large drive shaft force is applied to a control shaft by using a linear motion conversion mechanism in which a linear motion shaft and a rotary body that rotates are connected. As a kind of such a valve lift actuator, Patent Document 1 discloses that a rotating body of a rotation / linear motion conversion mechanism is rotationally driven by an electric motor.

  Specifically, in the valve lift actuator disclosed in Patent Document 1, a first storage chamber and a second storage chamber that are adjacent to each other are formed inside the main body housing, and a seal member that seals between the main body housing and the rotating body is the storage chamber. It is arranged at the boundary part. Here, the rotating body has a bottomed cylindrical shape in which the first end is opened in the first storage chamber and the second end is closed in the second storage chamber, and the linear motion shaft rotates inside the rotating body. Screwed into the body. In addition, a motor stator for exciting and rotating the rotating body by energization is accommodated in the second accommodation chamber, and an energization circuit portion for energizing the motor stator is adjacent to the second accommodation chamber. Are arranged.

Under such a configuration, the lubricating oil supplied from the internal combustion engine to the first storage chamber through the supply hole of the main body housing enters the inside of the rotary body that opens in the first storage chamber. It exerts a lubricating action and a cooling action on the threaded portion of the moving shaft. On the other hand, the lubricating oil supplied to the first storage chamber on the internal combustion engine side of the second storage chamber is prevented from flowing into the second storage chamber by the seal member, and the lubricating oil that has entered the rotating body is Inflow into the second storage chamber is prevented by closing the end of the rotating body on the second storage chamber side. Therefore, it is possible to avoid a situation in which the motor stator housed in the second housing chamber is in contact with the lubricating oil and fails.
2006-214291

  Incidentally, the lubricating oil supplied from the internal combustion engine in the valve lift actuator disclosed in Patent Document 1 enters the inside of the rotating body from the end on the first storage chamber side close to the internal combustion engine, and is closed. It flows through the inside of the rotating body toward the end on the side. For this reason, inside the rotating body, the circulation efficiency of the lubricating oil is deteriorated, and the lubricating oil may continue to stay. When the lubricating oil stays inside the rotating body in this way, foreign matter such as abrasion powder generated in the screwed portion is difficult to be discharged from the inside of the rotating body, and the closer to the end of the rotating body on the second storage chamber side, the cleaner the cleaner. Since it is difficult for the lubricating oil to reach the threaded portion, there is a concern that the durability may be lowered. In addition, the retention of lubricating oil inside the rotating body hinders heat dissipation from the inside, so that the durability is reduced due to deterioration of the lubricating oil, temperature rise of the energizing circuit portion arranged adjacent to the second storage chamber, etc. It is also possible to invite.

  The present invention has been made in view of the problems described above, and an object thereof is to provide a highly durable valve lift actuator.

  According to a first aspect of the present invention, there is provided a valve lift control device for controlling a valve lift amount of a valve to be controlled that is at least one of an intake valve and an exhaust valve of an internal combustion engine, and a control shaft for changing the valve lift amount. Lift actuator that linearly drives the first storage chamber and the second storage chamber adjacent to each other, the supply hole for supplying the lubricant from the internal combustion engine and the second storage chamber to the internal combustion engine side A main body housing having a discharge hole for discharging the lubricating liquid from the first storage chamber to the outside, and a bottomed base having a first end opened in the first storage chamber and a second end closed in the second storage chamber Rotating / linear motion converting mechanism having a cylindrical rotating body and a linear motion shaft that is screwed with the rotating body and linearly moves with the control shaft inside the rotating body, and converts the rotational motion of the rotating body into linear motion of the linear motion shaft. The seal member is disposed at the boundary between the first storage chamber and the second storage chamber and seals between the main body housing and the rotating body. The seal member is housed in the second storage chamber and is energized by energization to rotate the rotating body. A rotating stator having an external communication hole communicating with a supply hole outside the rotating body, and an external communication hole in the axial direction of the rotating body from the first end side toward the second end side. And an internal communication hole that communicates with the inside of the rotating body, and an external communication hole and a relay hole that relays between the internal communication holes.

  According to the first aspect of the present invention, the lubricating liquid supplied from the internal combustion engine to the supply hole of the main body housing is first introduced into the external communication hole communicating with the supply hole. Further, the introduced lubricating liquid enters the inside of the rotating body communicating with the internal communication hole through the internal communication hole relayed between the external communication hole by the relay hole. Here, the internal communication hole is separated from the external communication hole in the axial direction of the rotating body from the first end portion opened in the first storage chamber to the second end portion closed in the second storage chamber. is doing. Therefore, the lubricating liquid that has entered the inside of the rotating body flows from the second end side toward the first end part side and flows out from the opening of the first end part to the first containing chamber, thereby causing the first accommodation. It is discharged from the chamber to the outside of the main body housing through the discharge hole. According to this, since the circulation efficiency of the lubricating liquid is increased inside the rotating body, the retention of the lubricating liquid in the inside can be suppressed. Therefore, in the inside of the rotating body, clean lubricant is distributed to the linear motion shaft and the screwed portion of the rotating body regardless of the position in the axial direction, and foreign matters such as abrasion powder generated at the screwed portion are eliminated. Can do. Further, heat dissipation from the inside of the rotating body can be realized together with the outflow of the lubricating liquid from the inside, so that deterioration of the lubricating liquid can be avoided.

  In addition, according to the first aspect of the present invention, the lubricating liquid that has entered the inside of the rotating body is prevented from flowing into the second housing chamber due to the closure of the second end of the rotating body, and from the second housing chamber. Also, the lubricating liquid that has flowed out of the rotating body into the first storage chamber on the internal combustion engine side is prevented from flowing into the second storage chamber by the seal member at the boundary between the storage chambers. Accordingly, it is possible to avoid a situation in which the motor stator accommodated in the second accommodating chamber is in contact with the lubricating liquid and fails.

  As described above, according to the first aspect of the present invention, the lubricity and cooling properties inside the rotating body by the lubricating liquid are ensured over a long period of time, and failure of the motor stator is avoided. Can be realized.

  According to the second aspect of the present invention, since a plurality of internal communication holes are provided in the axial direction of the rotating body, it is possible to feed clean lubricating liquid substantially simultaneously into a plurality of locations in the axial direction of the threaded portion. According to this, since lubricity and cooling performance inside the rotating body by the lubricating liquid are enhanced, higher durability can be realized.

  According to the invention described in claim 3, the internal communication hole has a shape communicating with the inside of the rotating body on the radial line of the rotating body and inclined with respect to the radial line. In such an invention, as the flow of the lubricating liquid entering the inside of the rotating body from the internal communication hole, a flow in a direction inclined with respect to the radial line of the rotating body is generated, so that the lubricating liquid flows in the circumferential direction of the rotating body. Can be spread. According to this, since lubricity and cooling performance inside the rotating body by the lubricating liquid are enhanced, higher durability can be realized.

  According to the fourth aspect of the present invention, the rotating body has an internal thread portion that is screwed with the linear motion shaft, and the internal communication hole opens at the bottom of the valley or the top of the internal thread portion. According to this, the driving shaft force generated on the linear motion shaft by the rotational drive of the rotating body and the axial force acting on the linear motion shaft from the control shaft due to the valve spring reaction force of the valve to be controlled are used. Even in the state of being in close contact with the flank of the female threaded portion, the lubricating liquid can be surely infiltrated into the rotating body from the internal communication hole opened at the valley or peak of the female threaded portion.

  According to the invention described in claim 5, the internal communication hole opens at the bottom of the female screw. As described above, the internal communication hole that opens to the bottom of the female screw is easier to secure the meat around the hole than the case where the internal communication hole that penetrates the thread of the female screw and opens to the top of the mountain is provided. Therefore, the strength reduction of the rotating body due to the provision of the internal communication hole can be suppressed.

  According to the sixth aspect of the present invention, the main body housing slidably supports the rotating body in the first housing chamber, and the communicating portion of the supply hole and the external communication hole is located at the sliding interface between the main body housing and the rotating body. Provided. Thus, according to the invention in which the main body housing slides and supports the rotating body in the first storage chamber, the lubricating liquid is supplied from the communication portion of the supply hole and the external communication hole to the main body housing provided with the communication portion and the rotation. Even if it leaks to the sliding interface between the bodies, it can be guided to the first storage chamber. Therefore, it is possible to reliably prevent the lubricating liquid leaking from the communicating portion of the supply hole and the external communication hole from flowing into the sliding interface between the main body housing and the rotating body and flowing into the second storage chamber.

  According to the seventh aspect of the present invention, the linear motion shaft projects from the inside of the main body housing to the outside through the discharge hole, and is connected to the control shaft at the outside. In such an invention, the hole that is indispensable for connecting the linear motion shaft to the control shaft by projecting from the inside of the main body housing to the outside can be used as the discharge hole. According to this, since the configuration is simplified, the cost can be reduced.

  The invention described in claim 8 is provided with an energization circuit portion that is disposed adjacent to the opposite side of the second accommodation chamber to the first accommodation chamber and energizes the motor stator. In such an invention, as described above, the heat radiation from the inside of the rotating body is realized, so that the temperature rises in the energizing circuit portion adjacent to the second storage chamber that stores the second end side of the rotating body. Can be suppressed. Therefore, failure of the energization circuit portion can be avoided and durability can be enhanced.

  According to the ninth aspect of the present invention, the rotating body has an internal communication hole on the inner peripheral side of the motor rotor that rotates by receiving the magnetic field generated by the motor stator. A rotating nut is mounted concentrically, and a relay hole is formed between the motor rotor and the rotating nut. In such an invention, the motor rotor necessary for rotating the rotating body and the rotating nut necessary for converting the rotating motion of the rotating body into the linear motion of the linear motion shaft are individually provided for each function. It can be formed by the material. In addition, a rotating body in which the communication holes are relayed by the relay holes can be easily formed by attaching a rotary nut having the internal communication holes to the inner peripheral side of the motor rotor having the external communication holes. .

  According to the tenth aspect of the present invention, the relay hole is formed by covering the concave groove opened on the outer peripheral surface of the rotating nut with the inner peripheral surface of the motor rotor. According to this, since it is not necessary to provide a concave groove for forming the relay hole in the motor rotor that receives the magnetic field action from the motor stator, the magnetic field action in the motor rotor is disturbed due to the presence of the concave groove. Can be suppressed. Therefore, it is possible to accurately follow the rotational drive of the rotating body with respect to the energization to the motor stator.

  According to the eleventh aspect of the present invention, the motor rotor has the external communication hole in the portion that is disengaged from the inner peripheral side of the motor stator. According to this, since there is no external communication hole in the portion of the motor rotor that receives the magnetic field action on the inner periphery side of the motor stator, the magnetic field action in the motor rotor is disturbed due to the presence of such external communication hole. Can be suppressed. Therefore, it is possible to accurately follow the rotational drive of the rotating body with respect to the energization to the motor stator.

  Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings. In addition, the overlapping description is abbreviate | omitted by attaching | subjecting the same code | symbol to the corresponding component in each embodiment.

(First embodiment)
FIG. 2 shows a valve lift control device 1 having a valve lift actuator 10 according to an embodiment of the present invention. The valve lift control device 1 is mounted on a vehicle and controls the valve lift amount using the intake valve 3 of the internal combustion engine 2 as a control target valve. The valve lift control device 1 includes a change mechanism 4, a valve lift actuator 10, and the like.

  First, the changing mechanism 4 will be described. The change mechanism 4 has the configuration shown in FIG. 2 as disclosed in, for example, Japanese Patent Application Laid-Open No. 2001-263015, and is incorporated in the internal combustion engine 2. Specifically, the changing mechanism 4 includes a control shaft 12 connected to the linear motion shaft 34 of the valve lift actuator 10. The slider gear 14 that moves linearly with the control shaft 12 is helically splined to the input portion 15 and the swing cam 16, and the input portion 15 and the swing shaft 14 are moved according to the movement position of the control shaft 12 in the axial direction. The relative phase difference between the moving cams 16 changes. Here, the input unit 15 is in contact with the intake cam 18 of the cam shaft 17, and the swing cam 16 is provided so as to be in contact with the rocker arm 19 of the intake valve 3. The rocking angle of the rocker arm 19 changes according to the relative phase difference between the sixteen. Therefore, in the change mechanism 4, the valve lift amount of the intake valve 3 changes according to the movement position of the control shaft 12 that is linearly driven by the valve lift actuator 10, and thereby the valve characteristics such as the operating angle and the maximum valve lift amount are changed. Will be adjusted. In this embodiment, the valve spring reaction force transmitted from the intake valve 3 to the control shaft 12 acts on the control shaft 12 as an axial force directed to the side opposite to the valve lift actuator 10.

  Next, the valve lift actuator 10 will be described. As shown in FIG. 3, the valve lift actuator 10 includes a main body housing 20, a rotation / linear motion conversion mechanism 30, an oil seal 40, an electric motor 50, and an energization circuit unit 60.

  The main body housing 20 has a stepped cylindrical shape with a bottom, and is fixed to the internal combustion engine 2 in a state where the bottom wall portion 21 side is fitted to the fixed wall portion 7 of the cylinder head 6 of the internal combustion engine 2. The main body housing 20 has a first storage chamber 22 and a second storage chamber 23 adjacent to each other. Here, the first storage chamber 22 is located closer to the bottom wall 21 than the second storage chamber 23, that is, to the internal combustion engine 2 side.

  The rotation / linear motion conversion mechanism 30 is a feed screw mechanism having a rotating body 31 and a linear motion shaft 34.

  The rotating body 31 has a bottomed cylindrical shape as a whole, and is accommodated in the accommodation chambers 22 and 23 in a form straddling the first accommodation chamber 22 and the second accommodation chamber 23. Under such accommodation, the one end 31a in the axial direction of the rotating body 31 constitutes a first end 31a that opens in the first accommodating chamber 22, while the other end 31b in the axial direction of the rotating body 31 is A second end portion 31 b that is closed in the two storage chambers 23 is configured.

  In the present embodiment, the rotating body 31 is formed by concentrically mounting a rotating nut 33 on the inner peripheral side of the motor rotor 32 shared with the electric motor 50. In the rotating body 31, an internal thread portion 37 having a trapezoidal tooth cross section is provided in an intermediate portion in the axial direction of the rotating nut 33. Further, an intermediate portion in the axial direction of the motor rotor 32 in the rotating body 31 is supported from the outer peripheral side by a radial bearing 24 provided in the main body housing 20, and can freely rotate in both circumferential directions.

  The linear motion shaft 34 is a round rod-shaped screw shaft as a whole, and penetrates the bottom wall portion 21 of the main body housing 20 so as to be linearly movable in the axial direction. One end of the linear motion shaft 34 in the axial direction is concentrically inserted into the rotating body 31, and a male screw part 35 having a trapezoidal cross section is provided on the end side. The male screw portion 35 is screwed with the female screw portion 37 of the rotating nut 33 inside the rotating body 31. Accordingly, the axial movement position of the linear motion shaft 34 is changed according to the circumferential rotation position of the rotating body 31. That is, in the rotation / linear motion conversion mechanism 30, the rotational motion of the rotating body 31 is converted into the linear motion of the linear motion shaft 34.

  The other end in the axial direction of the linear motion shaft 34 enters the cylinder head 6, and the end is connected coaxially with the control shaft 12 via a coupling 36. As a result, the linear motion shaft 34 can linearly move in the axial direction together with the control shaft 12, and the axial force resulting from the valve spring reaction force of the intake valve 3 is transmitted from the control shaft 12 side. Yes.

  The oil seal 40 as a seal member is disposed at the boundary between the first storage chamber 22 and the second storage chamber 23 on the outer peripheral side of the motor rotor 32 of the rotating body 31. Under such an arrangement, the oil seal 40 seals between the main body housing 20 and the rotating body 31 that form the storage chambers 22 and 23 in a state in which the space between the first storage chamber 22 and the second storage chamber 23 is liquid-tightly partitioned. is doing.

  The electric motor 50 is a brushless motor having a motor rotor 32 and a motor stator 52.

  The motor rotor 32 includes a rotor core 53, a drive magnet 54, a sensor magnet 55, a magnetic holder 56, and the like. The rotor core 53 is made of a magnetic material and has a cylindrical shape. The drive magnets 54 are made of permanent magnets and are mounted on the rotor core 53 at a plurality of locations that are equally spaced in the circumferential direction. The drive magnets 54 adjacent to each other in the circumferential direction of the rotor core 53 form opposite magnetic poles on the outer peripheral surface side of the rotor core 53. The sensor magnet 55 is made of a permanent magnet and has an annular shape. The sensor magnet 55 is coaxially fixed to the rotor core 53 via the magnetic holder 56. The sensor magnet 55 is configured such that a plurality of magnetic poles formed on one end surface side in the axial direction conflict with each other adjacent in the circumferential direction.

  The motor stator 52 includes a stator core 57, a stator coil 58, and the like, and is accommodated in the second accommodation chamber 23. The stator core 57 is made of a magnetic material and has an annular block shape. The stator core 57 is concentrically disposed on the outer peripheral side of the motor rotor 32 and is fixed to the main body housing 20. The stator core 57 is provided with a plurality of tooth portions 59 protruding to the inner peripheral side. The stator coils 58 are individually wound around the teeth portions 59.

  The energization circuit unit 60 includes a driver housing 62, a motor driver 70, and a control circuit 80.

  The driver housing 62 is a combination of three members 64, 65 and 66. Here, the base member 64 is bolted to the opening side end of the main body housing 20. The intermediate member 65 is bolted to the opening side end of the main body housing 20 in such a form that the base member 64 is sandwiched between the intermediate member 65 and the main body housing 20. The cover member 66 is fitted and fixed to the intermediate member 65 from the side opposite to the base member 64. As described above, the driver housing 62 is disposed adjacent to the second housing chamber 23 on the opposite side of the first housing chamber 22 to form a driver chamber 67 that houses the motor driver 70.

  The motor driver 70 includes, for example, a bridge circuit and a driving IC, and is electrically connected to each stator coil 58 of the motor stator 52 via a harness 71 that passes through the intermediate member 65 and the base member 64. The motor driver 70 energizes each stator coil 58 to excite the coils 58 in a predetermined order, thereby generating a rotating magnetic field that acts on the motor rotor 32. Therefore, the rotating nut 33 is rotated together with the motor rotor 32 in the direction of the magnetic field generated by each stator coil 58, and the linear motion shaft 34 is linearly driven accordingly.

  The motor driver 70 is provided with a plurality of magnetic detection elements 72 exposed into the second storage chamber 23 through an inner peripheral hole 68 that penetrates the base member 64. Each magnetic detection element 72 is, for example, a Hall element, and is disposed so as to face the sensor magnet 55 of the motor rotor 32 in the axial direction. Each magnetic detection element 72 detects the rotational position of the rotating body 31 (motor rotor 32) based on the magnetic action received from the sensor magnet 55. Here, the motor driver 70 is electrically connected to the control circuit 80, and gives the detected rotational position of the rotating body 31 to the control circuit 80.

  In this embodiment, the control circuit 80 also serves as a control circuit for the internal combustion engine, and is disposed outside the housings 20 and 62. The control circuit 80 calculates the movement position of the linear motion shaft 34 (control shaft 12) based on the rotational position of the rotating body 31 given from the motor driver 70. Further, the control circuit 80 estimates the actual valve lift amount of the intake valve 3 from the calculated movement position of the linear movement shaft 34, and issues a feedback control command based on the difference between the actual valve lift amount and the target valve lift amount to the motor driver 70. Give to. By energizing each stator coil 58 from the motor driver 70 in accordance with this control command, the control shaft 12 is linearly driven together with the linear motion shaft 34 to achieve the target valve lift amount. Note that the target valve lift amount is set by the control circuit 80 based on, for example, the operating state of the vehicle such as the rotational speed of the internal combustion engine and the accelerator opening.

  Next, the characteristic part of 1st embodiment is demonstrated in detail.

  As shown in FIG. 3, the cylinder head 6 of the internal combustion engine 2 forms a conveyance path 90. This conveyance path 90 is connected to the oil pump 8 of the internal combustion engine 2, and extends to the fitting hole 91 in which the main body housing 20 is fitted in the fixed wall portion 7. Here, the oil pump 8 is a mechanical pump that is driven by the rotational output of the internal combustion engine 2. Therefore, the lubricating oil discharged from the oil pump 8 as “lubricating liquid” always passes through the conveyance path 90 during operation of the internal combustion engine 2. The main body housing 20 is supplied.

  The cylinder head 6 further has a discharge chamber 92 on the opposite side of the main body housing 20 with the fixed wall portion 7 interposed therebetween. The discharge chamber 92 is connected to the oil oil pan 9 of the oil pump 8, and the lubricating oil discharged from the main body housing 20 side to the discharge chamber 92 is returned to the oil pump 8 as will be described later.

  As shown in FIG. 1, in the stepped cylindrical main body housing 20, the first storage chamber 22 is formed on the inner peripheral side, fitted into the fitting hole 91, and fixed to the fixed wall portion 7. A supply hole 96 is formed in the peripheral wall portion 94. The supply hole 96 is formed in a cylindrical hole shape that radially penetrates between the outer peripheral surfaces of the peripheral wall portion 94, and is an opening of the conveyance path 90 that opens in an annular shape along the inner peripheral surface of the fitting hole 91. It communicates with the portion 90a. Therefore, during operation of the internal combustion engine 2, the lubricating oil discharged from the oil pump 8 is supplied to the supply hole 96 through the conveyance path 90.

  In the main body housing 20, a discharge hole 98 is formed in the bottom wall portion 21 that closes one end portion of the peripheral wall portion 94. The discharge hole 98 is formed in a cylindrical hole shape that penetrates between the outer surfaces of the bottom wall portion 21 in the axial direction, and communicates between the first storage chamber 22 and the discharge chamber 92. Further, the linear motion shaft 34 is coaxially inserted into the discharge hole 98, whereby the linear motion shaft 34 protrudes from the inside of the main body housing 20 to the outside through the discharge hole 98 and enters the discharge chamber 92 serving as the outside. Thus, it is connected to the control shaft 12. Furthermore, in this embodiment, the linear movement shaft 34 is slidably fitted in a straight spline with the discharge hole 98 so as to be slidable in the axial direction. Thus, the lubricating oil is discharged from the first storage chamber 22 to the discharge chamber 92 through the sliding interface between the discharge hole 98 and the linear motion shaft 34.

  As shown in FIGS. 1 and 4, the cylindrical rotor core 53 constituting the motor rotor 32 is supported not only by the radial bearing 24 but also by the peripheral wall portion 94 of the main body housing. Here, the peripheral wall portion 94 of the present embodiment slides and supports the outer peripheral surface of the rotor core 53 in the first storage chamber 22 by the inner peripheral surface where the supply hole 96 opens.

  In addition, the rotor core 53 is formed with an external communication hole 100 in a portion constituting the first end portion 31 a of the rotating body 31 by being removed from the inner peripheral side of the motor stator 52. In this external communication hole 100, the annular groove-shaped introduction hole portion 100 a that opens to the outer peripheral surface of the rotor core 53 is on the inner peripheral side with respect to the supply hole 96 provided in the peripheral wall portion 94 that is the outside of the rotating body 31. Is located. As a result, the introduction hole 100a is always in communication with the supply hole 96 in the sliding interface between the rotor core 53 and the peripheral wall 94 supporting the rotor core 53. That is, the communicating part of the introduction hole part 100 a and the supply hole 96 is provided at the sliding interface between the rotor core 53 and the peripheral wall part 94. Further, in the external communication hole 100, a cylindrical hole-shaped through hole portion 100 b penetrates between the bottom surface of the introduction hole portion 100 a and the inner peripheral surface of the rotor core 53 in the radial direction.

  As shown in FIG. 1, the rotating nut 33 includes a nut body 110, a first cap 120, a second cap 130, and the like.

  As shown in FIGS. 1, 4, and 5, the nut body 110 having the female threaded portion 37 on the inner peripheral portion is formed of a metal material different from that of the rotor core 53, so that its strength is enhanced. On the outer peripheral surface of the nut main body 110, a concave groove 112 extending over the entire length in the axial direction is opened. Here, the nut main body 110 is press-fitted concentrically with the rotor core 53, and the concave groove 112 is covered with the inner peripheral surface of the rotor core 53, thereby forming a relay hole 114 between the nut main body 110 and the rotor core 53. is doing. Further, the concave groove 112 is aligned in the circumferential direction with respect to the through hole portion 100b of the rotor core 53, whereby the relay hole 114 communicates with the through hole portion 100b.

  As shown in FIGS. 1 and 5, the nut main body 110 has internal communication holes 116 at a plurality of locations spaced from the external communication holes 100 in the axial direction from the first end 31 a side to the second end 31 b side of the rotating body 31. Is forming. Each of the internal communication holes 116 is formed in a cylindrical hole shape that penetrates the nut main body 110 radially inward from the bottom surface of the concave groove 112, and is provided in a line in the axial direction of the rotating body 31. Thus, each internal communication hole 116 communicates with the relay hole 114 and is relayed between the external communication hole 100 by the relay hole 114.

  As shown in FIG. 6, the end of each internal communication hole 116 opposite to the relay hole 114 (concave groove 112) is open to the valley bottom 37 a of the corresponding female screw part 37. As a result, each internal communication hole 116 communicates between the flank 37 b of the female screw portion 37 in the rotating body 31 surrounded by the inner peripheral portion of the nut body 110.

  As shown in FIG. 1, the first cap 120 constitutes a first end portion 31 a of the rotating body 31 by fitting the cylindrical fitting portion 122 to the nut body 110. Further, in the first cap 120, the annular plate-like flange portion 124 projects radially outward from the fitting portion 122 so as to straddle both the nut main body 110 and the rotor core 53 in the radial direction. Accordingly, the flange portion 124 closes the end portion 114 a of the relay hole 114 with respect to the first storage chamber 22 at the first end portion 31 a of the rotating body 31.

  The second cap 130 is formed in a bottomed stepped cylindrical shape, and the large-diameter portion 132 on the opening side is fitted into the rotor core 53, thereby constituting the second end portion 31b of the rotating body 31 and the end. In the portion 31 b, the end portion 114 b of the relay hole 114 is closed with respect to the second storage chamber 23. Further, a seal ring 134 is interposed between the large diameter portion 132 of the second cap 130 and the rotor core 53, and thereby the inside of the rotating body 31 and the space between the second storage chambers 23 are sealed in a liquid-tight manner. Yes.

  As described above, the lubricating oil supplied from the operating internal combustion engine 2 to the supply hole 96 is first introduced into the introduction hole portion 100 a of the external communication hole 100 and then relayed through the through hole portion 100 b of the same external communication hole 100. Flow into. Further, the inflow lubricating oil penetrates into the inside of the rotating body 31 almost simultaneously from a plurality of positions in the axial direction through the respective internal communication holes 116, and lubricates the screwed portions of the screw portions 37 and 35. It flows to the first end portion 31a side while cooling. Therefore, the lubricating oil used for lubrication and cooling inside the rotating body 31 flows out from the gap 140 (see FIG. 1) between the first end portion 31a of the rotating body 31 and the linear motion shaft 34 into the first storage chamber 22. Then, the gas is sequentially discharged through the discharge hole 98.

  Here, particularly in the first embodiment, each internal communication hole 116 is open to the valley bottom 37 a of the female screw portion 37. Therefore, even if the male screw portion 35 is in close contact with the flank 37b of the female screw portion 37 due to the drive shaft force generated on the linear motion shaft 34 or the valve spring reaction force acting on the linear motion shaft 34 from the control shaft 12, Lubricating oil can be reliably infiltrated between the flank 37b which becomes the inside of the rotary body 31.

  According to such a first embodiment, since the circulation efficiency of the lubricating oil is increased inside the rotating body 31, the situation in which the lubricating oil stays in the screwed portions of the screw portions 37 and 35 inside the rotating body 31 is avoided. Can be suppressed. Therefore, in the rotating body 31, clean lubricating oil spreads over the screwed portions of the screw portions 37 and 35 depending on the axial position thereof, and foreign matters such as wear powder generated at the screwed portions are easily removed. . In addition, as the lubricating oil sequentially flows from the inside of the rotating body 31 to the first storage chamber 22, heat dissipation from the inside proceeds, so that the deterioration of the lubricating oil and the energization circuit section adjacent to the second storage chamber 23 are achieved. Thermal failure of 60 motor drivers 70 can be avoided.

  Furthermore, in the first embodiment, the lubricating oil that has entered the inside of the rotating body 31 is prevented from flowing into the second storage chamber 23 from the end 31b due to the blockage of the second end 31b. Even if it flows out into the second storage chamber 23, the oil seal 40 prevents the flow into the second storage chamber 23. Moreover, in the first embodiment, the holes 96 and 100 of the peripheral wall portion 94 and the rotor core 53 communicate with each other in the sliding interface between the peripheral wall portion 94 and the rotor core 53 forming the first storage chamber 22. The leaked oil from the communicating part is also prevented from flowing into the second storage chamber 23. According to these, for the motor stator 52 accommodated in the second accommodating chamber 23 and the motor driver 70 in which the magnetic detection element 72 is exposed in the second accommodating chamber 23, it is possible to avoid failure due to contact of lubricating oil. it can.

  In the first embodiment, the external communication hole 100 is provided in the rotor core 53 so as to be disengaged from the inner peripheral side of the motor stator 52, and the relay hole 114 is formed between the rotor core 53 and the nut body 110. A concave groove 112 is provided on the nut body 110 side. Therefore, in the motor rotor 32 having the rotor core 53, the action of the magnetic field received from the motor stator 52 is not disturbed due to the presence of the external communication hole 100 and the concave groove 112. It is possible to accurately follow the energization to 52.

  According to the first embodiment described so far, the lubricity and cooling performance inside the rotating body 31 are ensured over a long period of time, and failure of the motor stator 52 and the motor driver 70 is avoided. The valve lift amount can be controlled with high accuracy under durability.

(Second embodiment)
As shown in FIGS. 7 and 8, the second embodiment of the present invention is a modification of the first embodiment. In each internal communication hole 216 of the second embodiment, the end portion on the opposite side to the relay hole 114 is open to the top 37c of the corresponding female screw portion 37. Thus, each internal communication hole 216 communicates with the inside of the rotating body 231 on the inner peripheral side of the crest 37c. Therefore, even if the male screw portion 35 is in close contact with the flank 37b of the female screw portion 37 due to the drive shaft force generated in the linear motion shaft 34 or the valve spring reaction force acting from the control shaft 12 to the linear motion shaft 34, Lubricating oil can be reliably infiltrated into the rotating body 31.

(Third embodiment)
As shown in FIGS. 9 and 10, the third embodiment of the present invention is a modification of the first embodiment. Each internal communication hole 316 of the third embodiment communicates with the flank 37b of the female thread portion 37 that is inside the rotary body 331 on the radial line R (see FIG. 10) of the rotary body 331, and the radial line R It is cylindrical hole shape which inclines to. In particular, each internal communication hole 316 of the present embodiment has a shape in which each internal communication hole 316 is inclined with respect to the radial line R on a virtual plane P (see FIG. 9) including the radial line R. Yes.

  In the third embodiment having such a configuration, a flow in a direction inclined with respect to the radial line R of the rotator 331 is generated as a flow of lubricating oil that enters the rotator 331 from each internal communication hole 316 to rotate. Lubricating oil can be sufficiently distributed in the circumferential direction of the body 331. According to this, since the lubricity and cooling performance inside the rotating body 331 are improved, higher durability can be realized.

(Other embodiments)
Although a plurality of embodiments of the present invention have been described above, the present invention is not construed as being limited to these embodiments, and can be applied to various embodiments without departing from the scope of the present invention. .

  Specifically, for the motor rotor 32 and the rotating nut 33 constituting the rotating bodies 31, 231, 331, for example, the rotor core 53 and the nut main body 110 may be integrally formed of the same material. In this case, the relay hole 114 can be formed by a through hole that penetrates the integral body of the rotor core 53 and the nut body 110 in the axial direction. On the other hand, as described above, when the rotor core 53 and the nut main body 110 are separated, the concave groove 112 provided on the inner peripheral surface of the rotor core 53 is covered with the outer peripheral surface of the nut main body 110 to form the relay hole 114. You may do it.

  A plurality of internal communication holes 116, 216, 316 may be provided side by side in the circumferential direction of the rotators 31, 231, 331, or the rotators 31, 231, 331 may have different circumferential positions. You may make it provide by shifting in the axial direction of 231 and 331. In these cases, a plurality of relay holes 114 and a plurality of through holes 110b of the external communication holes 100 can be provided so as to match the circumferential positions of the internal communication holes 116, 216, and 316. In addition to the above, the internal communication holes 116, 216, and 316 may be provided only at one place as far as possible from the external communication hole 100.

  About the opening form in the internal thread part 37 of the internal communication holes 116 and 316, you may change so that it may open to the flank 37b. Moreover, you may change about the opening form in the internal thread part 37 of the internal communication hole 316 so that it may open to the peak 37c of a mountain according to 2nd embodiment. Furthermore, the inclined form with respect to the radial line R of the internal communication hole 316 may be along the lead angle direction of the female screw portion 37. In addition, when the internal communication hole 316 is formed in a shape along the lead angle direction of the female screw portion 37 in this way, not only with respect to the radial line R but also with respect to the virtual plane P including the radial line R. But it will be inclined.

  As the rotation / linear motion conversion mechanism 30, a shaft in which the linear motion shaft 34 is eccentrically connected to the control shaft 12 may be employed. Further, as the electric motor 50, a motor other than the brushless motor described above may be employed as long as a part of the rotating body of the rotation / linear motion converting mechanism 30 is a rotor. Furthermore, in addition to the oil pump 8 of the internal combustion engine 2 composed of a mechanical pump, for example, a fluid supply source such as an electric pump that operates in accordance with the operation of the internal combustion engine 2 or in a timely manner may be used for supplying the lubricating oil (liquid). Good.

  As the change mechanism 4 to which the valve lift actuator 10 is combined, other than those described above, for example, a valve reaction force can be used as long as the valve lift amount can be changed according to the axial position of the control shaft 12. You may employ | adopt what acts on the control shaft 12 as an axial force which goes to the valve lift actuator 10 side. Further, as the change mechanism 4, a mechanism that uses an exhaust valve as a control target valve, or a mechanism that controls both an intake valve and an exhaust valve may be adopted.

It is sectional drawing which expands and shows the characteristic part of the valve lift actuator by 1st embodiment of this invention. It is the partial cross section schematic diagram (a) and the cross-sectional view (b) which show the valve lift control apparatus provided with the valve lift actuator by one Embodiment of this invention. It is sectional drawing which shows the valve lift actuator by 1st embodiment of this invention. It is the IV-IV sectional view taken on the line of FIG. It is the VV sectional view taken on the line of FIG. It is an enlarged view of the VI section of FIG. It is a figure which shows the valve lift actuator by 2nd embodiment of this invention, Comprising: It is sectional drawing corresponding to FIG. It is an enlarged view of the VIII part of FIG. It is a figure which shows the valve lift actuator by 3rd embodiment of this invention, Comprising: It is sectional drawing corresponding to FIG. FIG. 10 is a sectional view taken along line XX in FIG. 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Valve lift control apparatus, 2 Internal combustion engine, 3 Intake valve (valve to be controlled), 4 Change mechanism, 6 Cylinder head, 7 Fixed wall part, 8 Oil pump, 9 Oil oil pan, 10 Valve lift actuator, 12 Control shaft, DESCRIPTION OF SYMBOLS 20 Main body housing, 21 Bottom wall part, 22 1st accommodating chamber, 23 2nd accommodating chamber, 30 Rotary linear motion conversion mechanism, 31,231,331 Rotating body, 31a 1st end part, 31b 2nd end part, 32 Motor rotor , 33 Rotating nut, 34 Linear shaft, 35 Male thread part, 37 Female thread part, 37a Valley bottom, 37b Frank, 37c Mountain peak, 40 Oil seal (seal member), 50 Electric motor, 52 Motor stator, 53 Rotor core, 54 Drive Magnet, 55 Sensor magnet, 56 Magnetic holder, 57 Stator core, 58 Stator coil, 60 energization circuit section, 62 driver housing, 70 motor driver, 80 control circuit, 90 transport path, 90a opening, 92 discharge chamber, 94 peripheral wall section, 96 supply hole, 98 discharge hole, 100 external communication hole, 100a introduction hole section , 100b through-hole portion, 110 nut body, 112 concave groove, 114 relay hole, 116, 216, 316 internal communication hole, 120 first cap, 122 fitting portion, 124 flange portion, 130 second cap, 132 large diameter portion , 134 Seal ring, 140 Clearance, R radial line, P Virtual plane

Claims (11)

In a valve lift control device that controls a valve lift amount of a control target valve that is at least one of an intake valve and an exhaust valve of an internal combustion engine, a valve lift actuator that linearly drives a control shaft for changing the valve lift amount. And
A first storage chamber and a second storage chamber that are adjacent to each other are formed inside, a supply hole through which the lubricating liquid is supplied from the internal combustion engine, and an exterior from the first storage chamber on the internal combustion engine side of the second storage chamber A main body housing having a discharge hole for discharging the lubricating liquid;
A bottomed cylindrical rotating body having a first end opened in the first storage chamber and a second end closed in the second storage chamber, and the control unit that is screwed with the rotating body inside the rotating body. A rotation / linear motion conversion mechanism that has a linear motion shaft that linearly moves together with the shaft, and that converts the rotational motion of the rotating body into linear motion of the linear motion shaft;
A seal member disposed at a boundary portion between the first storage chamber and the second storage chamber and sealing between the main body housing and the rotating body;
A motor stator housed in the second housing chamber and energized by energization to rotationally drive the rotating body,
The rotating body is
An external communication hole communicating with the supply hole outside the rotating body;
An internal communication hole that is provided apart from the external communication hole in the axial direction of the rotating body from the first end side toward the second end side, and communicates with the inside of the rotating body;
A valve lift actuator comprising: the external communication hole and a relay hole that relays between the internal communication hole.   The valve lift actuator according to claim 1, wherein a plurality of the internal communication holes are provided in the axial direction of the rotating body.   3. The valve lift according to claim 1, wherein the internal communication hole has a shape that communicates with the inside of the rotating body on the radial line of the rotating body and is inclined with respect to the radial line. Actuator. The rotating body has a female thread portion that is screwed with the linear motion shaft,
The valve lift actuator according to any one of claims 1 to 3, wherein the internal communication hole opens at a valley bottom or a mountain peak of the female screw portion.   The valve lift actuator according to claim 4, wherein the internal communication hole opens at a valley bottom of the female screw. The main body housing slidably supports the rotating body in the first storage chamber,
The valve lift actuator according to any one of claims 1 to 5, wherein a communication portion of the supply hole and the external communication hole is provided at a sliding interface between the main body housing and the rotating body. .   The valve lift according to any one of claims 1 to 6, wherein the linear movement shaft projects from the inside of the main body housing to the outside through the discharge hole and is connected to the control shaft at the outside. Actuator.   8. The energization circuit section for energizing the motor stator is disposed adjacent to the second accommodation chamber on the opposite side to the first accommodation chamber. The valve lift actuator as described in.   The rotating body has a concentric rotating nut that has the internal communication hole and is screwed to the linear motion shaft on the inner peripheral side of the motor rotor that has the external communication hole and rotates in response to a magnetic field generated by the motor stator. The valve lift actuator according to any one of claims 1 to 8, wherein the valve lift actuator is mounted on the relay rotor and the relay hole is formed between the motor rotor and the rotating nut.   10. The valve lift actuator according to claim 9, wherein the relay hole covers a concave groove opened on an outer peripheral surface of the rotating nut with an inner peripheral surface of the motor rotor.   11. The valve lift actuator according to claim 9, wherein the motor rotor has the external communication hole in a portion that is disengaged from an inner peripheral side of the motor stator.

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