JP4314209B2 - Actuator of valve lift control device - Google Patents

Description

  The present invention relates to an actuator for a valve lift control device that controls a lift amount of at least one of an intake valve and an exhaust valve of an internal combustion engine.

2. Description of the Related Art Conventionally, in a valve lift control device, an actuator that linearly drives a control shaft has been widely used in order to change the lift amount of a control target valve in accordance with the axial position of the control shaft.
As an actuator for such a valve lift control device, an actuator has been proposed in which the rotational driving force of a motor is converted into a linear driving force through a speed reduction mechanism and a cam mechanism, and the linear driving force is transmitted to a control shaft (for example, a patent). Reference 1).

JP 2004-150332 A

In the above-described actuator, in order to give a large linear driving force to the control shaft, a combination of a speed reduction mechanism and a cam mechanism must be used. For this reason, there is a limit in reducing the overall physique, which may cause problems such as restrictions on the installation location.
Therefore, the present inventors have intensively studied an actuator using a feed screw mechanism that converts the rotational motion of the rotary shaft into the linear motion of the screw shaft instead of the speed reduction mechanism and the cam mechanism. In general, a feed screw mechanism can obtain a large linear driving force with a relatively simple configuration in which a rotating shaft and a screw shaft are directly or indirectly linked, so that compared to a combination of a speed reduction mechanism and a cam mechanism. Thus, the size of the actuator can be reduced.

Now, the present inventors have further studied the actuator using the feed screw mechanism, and the axial end portion of the bearing that supports the radial force of the rotating shaft is locked by the housing case of the feed screw mechanism. An actuator has been developed that engages a fixed regulating member with the other axial end of the bearing. In this actuator, the axial displacement of the bearing and further the axial displacement of the rotating shaft can be restricted, so that it is possible to prevent damage caused by the axial displacement of the rotating shaft in the event of an abnormal increase in the acting force on the screw shaft. . However, in this actuator, since the regulating member is additionally fixed to the housing case of the feed screw mechanism in which the motor stator for rotational driving of the rotary shaft is fixed, the number of fastening members such as fixing screws is reduced. As a result, new problems such as a reduction in assembly and an increase in weight have occurred.
The present invention has been made in view of these problems, and an object of the present invention is to provide an actuator for a valve lift control device that achieves improved assembly and weight reduction.

  According to the first aspect of the present invention, the restricting member is engaged with the other axial end of the bearing that is locked by the housing case of the feed screw mechanism and supports the radial force of the rotating shaft, and the bearing In the axial direction, the motor stator engages with the restriction member from the side opposite to the bearing. Here, since the motor stator is locked by the case, the restricting member can be positioned between the motor stator and the bearing in the axial direction of the bearing to perform the function of restricting the axial displacement of the bearing. Therefore, there is no need to fix the restricting member to the case with a fastening member such as a screw, so that the number of parts can be reduced, and assemblability can be improved and the weight can be reduced.

According to the invention described in claim 2, since the elastic deformation of the restricting member is permitted by the space formed around the restricting member, the restoring force generated in the elastically deforming restricting member is applied to the bearing to It can be pressed toward the locking portion side of the case. Thereby, the axial displacement of the bearing can be regulated while absorbing the backlash between the regulating member and the bearing.
According to the third aspect of the present invention, since the space portions are formed on both sides sandwiching the regulating member in the axial direction of the bearing, the elastic deformation of the regulating member can be sufficiently allowed.

According to the fourth aspect of the present invention, the fitting portion having a shape extending in the circumferential direction of the rotating shaft in the restricting member is fitted into the inner peripheral wall of the case surrounding the outer peripheral side of the rotating shaft. The member can be positioned.
According to the fifth aspect of the present invention, the fitting portion having a shape extending in the circumferential direction of the rotating shaft in the restricting member is fitted into the inner peripheral wall of the case surrounding the outer peripheral side of the rotating shaft. The member can be positioned. As a result, the engaging portion that engages with the bearing is less likely to be displaced in the radial direction of the bearing, so that the restoring force generated by elastic deformation of the elastically deforming portion between the engaging portion and the fitting portion is reduced to the bearing. It can be made to act stably.

  According to the sixth aspect of the present invention, the elastically deforming portion includes a first deforming portion disposed between the fitting portion and the bearing in the form of a double cylinder structure with the fitting portion, and the fitting portion and the first portion. It is comprised from the 2nd deformation | transformation part connected between one deformation | transformation part. Thereby, the restoring force can be increased by arranging as large an elastically deformable portion as possible using the space between the fitting portion and the bearing.

According to the seventh aspect of the present invention, since the engaging portion and the elastically deforming portion have a shape extending in the entire circumferential direction of the bearing, the restoring force of the regulating member acting on the bearing is biased in the circumferential direction of the bearing. Can be suppressed. Therefore, the restriction function of the axial displacement of the bearing can be stably obtained.
According to the eighth aspect of the present invention, the fitting portion having a shape extending in the entire circumferential direction of the rotating shaft is fitted to the inner peripheral wall of the case surrounding the outer peripheral side of the rotating shaft. The positioning accuracy of the member is increased.

  According to the ninth aspect of the present invention, the outer peripheral portion of the stator core having a shape extending in the circumferential direction of the rotating shaft in the motor stator is fitted and held on the inner peripheral wall of the case surrounding the outer peripheral side of the rotating shaft. It will have rigidity. And since this highly rigid outer peripheral part engages with the regulating member, it is possible to prevent the stator core from being deformed by the reaction force received from the regulating member, and the situation where the positioning function of the regulating member and the original performance of the motor stator deteriorate. .

According to the invention of claim 10, in the case, the cover member is fixed to the main body member so as to cover the opening of the main body member for locking the bearing, and from the side opposite to the regulating member in the axial direction of the bearing to the motor stator. Engage. As a result, the motor stator is locked by the cover member fixed to the main body member, and the positioning member positioning function, and thus the axial displacement regulating function of the bearing can be reliably exhibited.
According to the eleventh aspect of the present invention, the cover member not only has a function of locking the motor stator but also a function of holding the energization circuit of the motor stator, so that the number of parts can be reduced and the cost can be reduced. it can.

Hereinafter, a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A valve lift control device according to a first embodiment of the present invention is shown in FIG. The valve lift control device 2 mounted on the vehicle controls the lift amount of the intake valve 4 of the internal combustion engine 3. The valve lift control device 2 includes a change mechanism 8 and an actuator 10.

  The change mechanism 8 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 3. Specifically, in the change mechanism 8 of FIG. 2, a slider gear 14 that can move linearly with the control shaft 12 in the axial direction of the control shaft 12 is helically splined to the input portion 15 and the swing cam 16. The relative phase difference between the input unit 15 and the swing cam 16 changes according to the position in the axial direction. The input portion 15 is in contact with the intake cam 18 of the cam shaft 17, and the swing cam 16 is disposed so as to be in contact with the rocker arm 19 of the intake valve 4, and the relative phase difference between the input portion 15 and the swing cam 16 is arranged. Accordingly, the rocking angle of the rocker arm 19 changes. Therefore, in the change mechanism 8, the lift amount of the intake valve 4 (hereinafter simply referred to as the valve lift amount) changes as the axial position of the control shaft 12 changes. Such valve characteristics are adjusted. In this embodiment, the valve reaction force transmitted from the intake valve 4 to the control shaft 12 acts on the control shaft 12 as a thrust force directed to the side opposite to the actuator 10.

  The actuator 10 linearly drives the control shaft 12 of the change mechanism 8 in the axial direction. As shown in FIG. 1, the actuator 10 includes a case 20, a feed screw mechanism 21, a bearing 22, a restriction plate 23, a motor 24, a rotation angle sensor 25, and a drive circuit 26. The actuator 10 is mounted on the vehicle so that the horizontal direction in FIG. 1 is substantially horizontal.

  The case 20 is configured by combining a case main body 30, a rotation restriction bush 31, a main body cover 32, and a circuit cover 33. The case body 30 is formed in a stepped cylindrical shape, and includes an attachment portion 34, a locking portion 35, a fitting peripheral wall portion 36, and a flange portion 37 in order from one end portion in the axial direction toward the other end portion. The attachment portion 34 is inserted and attached to the attachment hole 5 of the internal combustion engine 3, whereby the case main body 30 is positioned with respect to the internal combustion engine 3. The rotation restricting bush 31 is formed in a cylindrical shape and is press-fitted into the inner peripheral wall of the attachment portion 34. The main body cover 32 and the circuit cover 33 are each formed in a cup shape, and are fastened together with the flange portion 37 in a state where the opening edge portions are overlapped with each other. By this fastening, the main body cover 32 covers the opening 38 on the flange portion 37 side of the case main body 30, and a circuit chamber 39 is formed between the main body cover 32 and the circuit cover 33.

The feed screw mechanism 21 is a trapezoidal screw mechanism formed by meshing the rotary shaft 40 and the screw shaft 41, and is housed inside the case body 30.
As shown in FIG. 3, the rotary shaft 40 is configured by combining a rotary sleeve 42, a seal sleeve 43, a seal lid 44, and a circlip 45. The rotating sleeve 42 is formed in a cylindrical shape and is arranged substantially coaxially with the case main body 30. A female thread 46 having a trapezoidal cross section is formed on the inner peripheral wall of the intermediate portion in the axial direction of the rotating sleeve 42. A male screw 47 is formed on the outer peripheral wall at one axial end of the rotating sleeve 42. The seal sleeve 43 is formed in a cylindrical shape, and is attached substantially coaxially to the other axial end of the rotary sleeve 42. An oil seal 48 is interposed between the seal sleeve 43 and the mounting portion 34, and a drive chamber 49 and an oil chamber 50 that are liquid-tightly partitioned by the oil seal 48 are formed inside the case body 30. ing. The seal lid 44 is formed in a disk shape, and is attached to the rotary sleeve 42 so as to cover the opening of the rotary sleeve 42 opposite to the seal sleeve 43. The circlip 45 is formed in a C shape and is fitted to the outer peripheral wall of the rotating sleeve 42 so as not to be relatively displaceable in the axial direction.

  As shown in FIG. 1, the screw shaft 41 is formed in a rod shape and is arranged substantially coaxially with the rotary shaft 40. One end of the screw shaft 41 in the axial direction protrudes outside the case body 30 and enters the oil passage 6 of the internal combustion engine 3, and is connected substantially coaxially to the control shaft 12 via a joint 53. Therefore, the screw shaft 41 reciprocates linearly with the control shaft 12 in the axial direction. As shown in FIG. 3, a male screw 54 having a trapezoidal cross section is formed on the outer peripheral wall on the other axial end side of the screw shaft 41, and this male screw 54 is screwed with a female screw 46 of the rotating sleeve 42. Yes. A clearance that allows linear movement of the screw shaft 41 is formed between the screw shaft 41 and the seal sleeve 43. Spline teeth 56 and 57 are formed on the outer peripheral wall of the axially intermediate portion of the screw shaft 41 and the inner peripheral wall of the rotation restricting bush 31 so as to mesh with each other by concave and convex fitting. As a result, the screw shaft 41 whose rotation in the circumferential direction is regulated follows the forward / reverse rotational movement of the rotary shaft 40 and reciprocates linearly in the axial direction. That is, in the feed screw mechanism 21, the rotary motion of the rotary shaft 40 is converted into the linear motion of the screw shaft 41.

  In this embodiment, part of the lubricating oil discharged from the oil pump 7 of the internal combustion engine 3 shown in FIG. 1 is attached to the mounting portion 34 and the oil passages 61 and 60 of the rotation restriction bush 31, the screw shaft 41, the rotation restriction bush 31, and the like. The oil chamber 50 is supplied to the oil chamber 50. The lubricating oil supplied to the oil chamber 50 passes between the screw shaft 41 and the seal sleeve 43 and flows into the rotary sleeve 42 to lubricate, for example, the meshing portions of the screws 46 and 54. The lubricating oil is discharged from the oil chamber 50 through the oil passage 62 of the mounting portion 34 to the oil passage 6 and then returned to the oil pan on the suction side of the oil pump 7.

  As shown in FIG. 3, the bearing 22 is a radial contact type ball bearing in which a ball-shaped rolling element 65 is sandwiched between an inner ring 63 and an outer ring 64, and is accommodated in a drive chamber 49 inside the case body 30. Has been. The inner ring 63 is fitted to the outer peripheral wall of the rotary sleeve 42, and the circlip 45 is engaged with one end of the inner ring 63 in the axial direction via a leaf spring 66. The outer ring 64 is fitted to the inner peripheral wall of the cylindrical portion 67 formed in the locking portion 35, and the locking portion 35 is engaged with the one axial end portion 64 a of the outer ring 64 via the washer 68. Yes. That is, the end portion 64 a of the outer ring 64 is locked by the locking portion 35. With the above configuration, the bearing 22 supports the radial force acting on the rotating shaft 40.

  The restriction plate 23 is made of stainless steel or the like and has elasticity. As shown in FIGS. 3 and 4, the regulation plate 23 is provided with a fitting portion 70, an elastic deformation portion 71 and an engaging portion 72. The fitting portion 70 is formed in a cylindrical shape and is fitted to the inner peripheral wall of the fitting peripheral wall portion 36 that surrounds the outer peripheral side of the rotating shaft 40. As will be described in detail later, the axial end portion 70 a of the fitting portion 70 is locked by a motor stator 82 of the motor 24. The first deformation portion 73 of the elastic deformation portion 71 is formed in a stepped cylindrical shape that changes in diameter at the intermediate portion in the axial direction, and forms a double cylinder structure with the fitting portion 70, and the fitting portion 70 and the bearing 22. Arranged between. The small diameter portion 73 a of the first deformable portion 73 is fitted to the outer peripheral wall of the outer ring 64, and the large diameter portion 73 b of the first deformable portion 73 forms a space portion 75 between the cylindrical portion 67. On the other hand, the second deformation portion 74 of the elastic deformation portion 71 has an annular plate shape protruding from the large diameter portion 73b of the first deformation portion to the outer peripheral side and connected to the end portion on the opposite side to the end portion 70a of the fitting portion 70. Formed and disposed between the fitting portion 70 and the cylindrical portion 67. And the space parts 76 and 77 are formed in the both sides which pinch | interpose the 2nd deformation | transformation part 74 to an axial direction. The elastic deformation portion 71 composed of such deformation portions 73 and 74 is allowed to be elastically deformed by the surrounding space portions 75, 76, and 77. The engaging portion 72 is formed in an annular plate shape that protrudes from the small diameter portion 73 a of the first deforming portion 73 toward the inner peripheral side, and is engaged with an end portion on the opposite side to the end portion 64 a of the outer ring 64. Therefore, the outer ring 64 is locked from the side opposite to the locking portion 35 by the restriction plate 23 locked by the motor stator 82. In this locked state, when the elastic deformation portion 71 is elastically deformed following the axial displacement of the bearing 22, a restoring force corresponding to the elastic deformation amount is generated in the restriction plate 23, and the engagement portion 72 causes the bearing 22 to be It is pressed toward the locking part 35 side.

As shown in FIG. 1, the motor 24 is a brushless motor having a motor rotor 80, a rotor fixing nut 81, and a motor stator 82, and is accommodated in a drive chamber 49 inside the case body 30.
As shown in FIGS. 3 and 5, the motor rotor 80 is configured by combining a rotor core 83 and a rotor magnet 84. The rotor core 83 is formed with an annular plate-like core protrusion 86 that protrudes from the one axial end of the cylindrical core body 85 toward the inner peripheral side. The core protrusion 86 is fitted to the outer peripheral wall of the intermediate portion in the axial direction of the rotary sleeve 42. An annular plate-shaped sleeve protrusion 87 protruding from the axial intermediate portion of the rotating sleeve 42 to the outer peripheral side is engaged with one axial end portion of the core protrusion 86, and a positioning key 88 is disposed on the protrusion 86. , 87. The rotor magnets 84 are permanent magnets having a circular arc shape in cross section, and a plurality of rotor magnets 84 are attached to the outer peripheral wall of the core body 85 at equal intervals in the circumferential direction.

  As shown in FIG. 3, a female screw 89 is formed on the inner peripheral wall of the rotor fixing nut 81 having a bottomed cylindrical shape. The female screw 89 is screwed with the male screw 47 of the rotary sleeve 42, whereby the core protrusion 86 is sandwiched between the rotor fixing nut 81 and the sleeve protrusion 87 and fixed to the rotary shaft 40. Therefore, the rotating shaft 40 also functions as a motor shaft.

  The motor stator 82 is configured by combining a stator core 90 and a stator coil 91. The stator core 90 is formed in a thick annular plate shape as a whole by stacking iron pieces, and is arranged substantially coaxially with a clearance on the outer peripheral side of the motor rotor 80. A plurality of slots 92 arranged at equal intervals in the circumferential direction are formed on the inner peripheral wall of the stator core 90, and a stator coil 91 is wound around each slot 92 via a stator bobbin (not shown). The outer peripheral portion 93 of the stator core 90 that is fitted to the inner peripheral wall of the fitting peripheral wall portion 36 is engaged with the restriction plate 23 from the side opposite to the axial bearing 22. Further, on the outer peripheral portion 93 of the stator core 90, a cylindrical inner fitting portion 94 formed on the main body cover 32 and fitted to the inner peripheral wall of the fitting peripheral wall portion 36 is engaged from the side opposite to the regulating plate 23. Yes. Therefore, the stator core 90 is locked by the internal fitting portion 94 of the main body cover 32 fixed to the case main body 30, and the regulation plate 23 is locked by the stator core 90.

As shown in FIG. 1, the rotation angle sensor 25 is a non-contact sensor having a magnet unit 100 and a sensing unit 101.
As shown in FIG. 3, the magnet unit 100 is configured by combining a sensor magnet 102, a magnet holder 103, and a positioning plate 104, and is accommodated in a drive chamber 49 inside the case body 30. The sensor magnet 102 is a permanent magnet formed in an annular plate shape, and forms magnetic poles at a plurality of locations in the circumferential direction. The magnet holder 103 is fitted to the rotor fixing nut 81 and holds the sensor magnet 102 substantially coaxially with respect to the rotating shaft 40. The positioning plate 104 is fitted to the core body 85, the rotor fixing nut 81, and the magnet holder 103, and positions the sensor magnet 102 in the circumferential direction with respect to each rotor magnet 84.
A plurality of Hall elements 105 constituting the sensing unit 101 are arranged at equal intervals in the circumferential direction of the rotating shaft 40. Each Hall element 105 faces the magnet unit 100 and detects the rotation angle of the rotating shaft 40 by sensing the magnetic field generated by the sensor magnet 102.

  As shown in FIG. 1, the drive circuit 26 is an electric circuit formed by laminating a plurality of substrates 107 on which the circuit elements 106 are mounted, and is held by the main body cover 32 while being accommodated in the circuit chamber 39. The drive circuit 26 is electrically connected to the stator coils 91, the hall elements 105, and the control circuit 108 outside the case 20. Here, the control circuit 108 is an electric circuit mainly composed of a microcomputer or the like. The control circuit 108 that receives the output of each Hall element 105 through the drive circuit 26 recognizes the rotation angle of the rotary shaft 40 and further the axial position of the control shaft 12, and determines the actual position from the recognized axial position of the control shaft 12. Estimate the valve lift. Then, the control circuit 108 commands the drive circuit 26 to energize the difference between the estimated actual valve lift amount and the target valve lift amount. The drive circuit 26 that has received a command from the control circuit 108 generates a rotating magnetic field on the outer peripheral side of the motor rotor 80 by controlling energization to each stator coil 91 in accordance with the command. By receiving this generated magnetic field, the motor rotor 80 rotates together with the rotary shaft 40, and the screw shaft 41 and the control shaft 12 linearly move in the axial direction in accordance with the rotation, so that a target valve lift amount is realized. Note that the target valve lift amount is a physical amount determined based on the driving state of the vehicle such as the rotational speed of the internal combustion engine 3, the accelerator opening degree, and the like.

  As described above, in the first embodiment, the restriction plate 23 that engages the bearing 22 that is locked to the locking portion 35 of the case body 30 from the side opposite to the locking portion 35 is the stator core 90 of the motor stator 82. Therefore, the bearing 22 is locked from the opposite side. Thus, the restriction plate 35 is positioned between the motor stator 82 and the bearing 22 in the axial direction of the bearing 22. Furthermore, in the first embodiment, the cylindrical fitting portion 70 of the restriction plate 23 is fitted into the cylindrical fitting peripheral wall portion 36 of the case body 30, and the cylindrical first deformation portion 73 of the restriction plate 23 is formed. The outer ring 64 of the bearing 22 is externally fitted. As a result, the regulation plate 35 is positioned with high accuracy between the case body 30 and the bearing 22 in the radial direction of the bearing 22. As described above, according to the restriction plate 35 that is positioned in the axial direction and the radial direction of the bearing 22, the axial displacement of the bearing 22 can be reliably restricted by the engaging portion 72 that engages with the bearing 22. This displacement restriction function is exhibited by the restriction plate 35 that is not fixed to the case body 30 by a fastening member such as a screw. Can be realized.

  In the first embodiment, since the elastic deformation portion 71 is allowed to be elastically deformed by the space portions 75, 76, and 77 around the restriction plate 23, the restoring force generated by the elastic deformation is applied to the bearing 22. Thus, the bearing 22 can be pressed toward the locking portion 35 of the case body 30. Furthermore, in the first embodiment, the elastic deformation portion 71 and the engagement portion 72 of the restriction plate 23 are formed in a cylindrical shape or an annular plate shape that extends in the entire circumferential direction of the bearing 22. It is possible to suppress the bias in the circumferential direction. Furthermore, in the first embodiment, the fitting portion 70 and the first deformation portion 73 of the restriction plate 23 are formed in a double cylinder structure, and the deformation portions 70 and 73 are connected by the second deformation portion 74. Thus, the large elastic deformation portion 71 composed of the deformation portions 73 and 74 can be disposed in the space between the fitting portion 70 and the bearing 22. Therefore, a large restoring force can be generated in the elastic deformation portion 71. As described above, according to the first embodiment, the bearing 22 can be pressed by exerting a large restoring force evenly on the bearing 22 in the circumferential direction, so that the backlash between the engaging portion 72 and the bearing 22 can be reduced. The axial displacement of the bearing 22 can be regulated while absorbing the above.

  Furthermore, in the first embodiment, since the stator core 90 is locked using the internal fitting portion 94 of the main body cover 32 that holds the drive circuit 26, the restriction plate 23 is attached to the core without increasing the number of parts. 90 can be locked and positioned. In addition, in the first embodiment, since the outer peripheral portion 93 of the annular plate-shaped stator core 90 is fitted and held in the cylindrical fitting peripheral wall portion 36, a clearance is provided between the motor rotor 80 and the outer peripheral portion 93. The stator core 90 has a higher rigidity than the inner peripheral portion. Since the highly rigid outer peripheral portion 93 is engaged with the restriction plate 23, the stator core 90 is deformed by a reaction force received from the restriction plate 23, and the positioning function of the restriction plate 23 and the original performance of the motor stator 82 are deteriorated. Can be prevented.

  As described above, in the first embodiment, the regulation plate 23 corresponds to the “regulation member” described in the claims, the case main body 30 corresponds to the “main body member” described in the claims, and the main body cover 32 includes the main body cover 32. It corresponds to a “cover member” recited in the claims, and the drive circuit 26 corresponds to an “energization circuit” recited in the claims.

(Second embodiment)
As shown in FIG. 6, the second embodiment of the present invention is a modification of the first embodiment, and the description of the components that are substantially the same as those of the first embodiment will be omitted by attaching the same reference numerals. .
In the regulation plate 200 of the second embodiment, the elastic deformation portion 201 that connects between the fitting portion 70 and the engaging portion 72 is formed in an annular flat plate shape. Space portions 202 and 203 are formed on both sides of the elastic deformation portion 201 in the axial direction, and elastic deformation of the elastic deformation portion 201 is allowed by the space portions 202 and 203. Therefore, the restoring force corresponding to the elastic deformation amount of the elastic deformation portion 201 can be applied to the bearing 22 from the engagement portion 72 to press the bearing 22 toward the locking portion 35. Therefore, the axial displacement of the bearing 22 can be reliably regulated by the same principle as in the first embodiment.
As described above, in the second embodiment, the regulation plate 200 corresponds to a “regulation member” described in the claims.

(Third embodiment)
As shown in FIG. 7, the third embodiment of the present invention is a modification of the first embodiment, and the description of the components that are substantially the same as those of the first embodiment will be omitted by providing the same reference numerals. .
The case main body 250 of the third embodiment is provided with a fixed peripheral wall portion 251 instead of the fitting peripheral wall portion 36. The difference between the fixed peripheral wall portion 251 and the fitting peripheral wall portion 36 is that the stator core 90 is screwed to the fixed peripheral wall portion 251 and that the inner fitting portion 94 is not engaged with the fixed peripheral wall portion 251. is there. According to the third embodiment, since the restriction plate 23 is locked by the stator core 90 fixed to the fixed peripheral wall portion 251 of the case body 30, it is not necessary to screw the restriction plate 23 to the case body 30. . Therefore, it is possible to reduce the number of parts by the same principle as in the first embodiment, thereby improving the assembling property and reducing the weight.
As described above, in the third embodiment, the case main body 250 corresponds to a “main body member” recited in the claims.

The first to third embodiments of the present invention have been described so far, but the present invention is not construed as being limited to these embodiments.
For example, in the first to third embodiments, the outer peripheral portion 93 of the stator core 90 constituting the motor stator 82 is engaged with the restriction plates 23 and 200, but in the stator core 90 other than the outer peripheral portion 93 or the motor stator 82. Other components may be engaged with the restriction plate. Moreover, in 1st-3rd embodiment, although the fitting part 70 of the control plates 23 and 200 is formed in the cylinder shape extended in the whole region of the circumferential direction, the length of the fitting part 70 is less than one round in the circumferential direction. You may form in the shape extended by. Furthermore, in the first to third embodiments, the elastic deformation portions 71, 201 and the engaging portion 72 of the regulation plates 23, 200 are formed in a cylindrical shape or an annular plate shape extending in the entire circumferential direction. At least one of the deforming parts 71, 201 and the engaging part 72 may be divided into a plurality in the circumferential direction.

  Furthermore, in the third embodiment, the stator core 90 is formed in an annular plate shape extending in the entire circumferential direction. However, the slots 92 of the stator core 90 are separated from each other in the circumferential direction, and each slot 92 is fixed to the fixed peripheral wall portion 251. It may be screwed to. In the third embodiment, the restriction plate 200 of the second embodiment may be used instead of the restriction plate 23.

  In the first to third embodiments, the feed screw mechanism 21 in which the rotary shaft 40 and the screw shaft 41 are directly meshed with each other is used. However, the rotary shaft 40 and the screw shaft 41 are gears, balls, or the like. Alternatively, a feed screw mechanism 21 that is indirectly linked via the above may be used. In the first to third embodiments, the constituent elements 42 to 45 of the rotating shaft 40 are formed as separate members, but at least two of them may be formed as a single member. In the first to third embodiments, the screw shaft 41 and the control shaft 12 are coaxially connected to each other. However, the screw shaft 41 may be eccentrically connected to the control shaft 12.

  In addition, in the first to third embodiments, a brushless motor is used as the motor 24 for driving the rotating shaft 40, but various known motors such as a DC motor may be used as the motor 24. In the first to third embodiments, the rotor magnet 84 may be embedded in the rotor core 83. Furthermore, in the first to third embodiments, the motor rotor 80 is sandwiched between the rotor fixing nut 81 and the sleeve protrusion 87 of the rotating sleeve 42 and fixed to the rotating shaft 40. You may fix to the rotating shaft 40 (rotating sleeve 42) by press injection.

  In addition, in the first to third embodiments, the control circuit 108 is provided outside the case 20. However, the control circuit 108 is housed inside the case 20 together with the drive circuit 26 as an “energization circuit” in claims. You may let them. In the first to third embodiments, the Hall element 105 is used as a sensor element constituting the sensing unit 101. However, for example, a magnetoresistive element may be used as the sensor element.

  In addition, the change mechanism 8 combined with the actuator 10 has a configuration other than the configuration described in the first embodiment as long as the valve lift amount is changed according to the axial position of the control shaft 12. It may be. For example, a change mechanism 8 that changes the lift amount of the exhaust valve of the internal combustion engine 3 may be used, and the valve reaction force transmitted to the control shaft 12 regardless of whether the target valve is a suction or an exhaust valve. Therefore, the change mechanism 8 that urges the screw shaft 41 toward the actuator 10 may be used.

It is sectional drawing which shows the actuator of the valve lift control apparatus by 1st embodiment. It is the fragmentary sectional schematic diagram (A) and sectional drawing (B) which show the valve lift control apparatus by 1st embodiment. It is sectional drawing which expands and shows the principal part of the actuator of the valve lift control apparatus by 1st embodiment. It is sectional drawing (A) and side view (B) which show the control plate of FIG. It is a figure which expands and shows the principal part of the actuator of the valve lift control apparatus by 1st embodiment, Comprising: It is VV sectional drawing of FIG. It is a figure which shows the actuator of the valve lift control apparatus by 2nd embodiment, Comprising: It is sectional drawing corresponding to FIG. It is a figure which shows the actuator of the valve lift control apparatus by 3rd embodiment, Comprising: It is sectional drawing corresponding to FIG.

Explanation of symbols

2 valve lift control device, 3 internal combustion engine, 4 intake valve, 8 change mechanism, 10 actuator, 12 control shaft, 20 case, 21 feed screw mechanism, 22 bearing, 23, 200 restriction plate (regulation member), 24 motor, 25 Rotation angle sensor, 26 Drive circuit, 30, 250 Case main body (main body member), 31 Rotation restriction bush, 32 Main body cover (cover member), 33 Circuit cover, 35 Locking portion, 36 Fitting peripheral wall portion, 38 Opening, 40 Rotating shaft, 41 Screw shaft, 63 Inner ring, 64 Outer ring, 64a End, 65 Rolling body, 67 Cylindrical part, 68 Washer, 70 Fitting part, 71, 201 Elastic deformation part, 72 Engagement part, 73 First deformation part 74, second deformed portion, 75, 76, 77, 202, 203 space portion, 82 motor stator, 90 stator core, 91 stator coil, 93 outer peripheral portion 94 in fitting portion, 108 control circuit, 251 a fixed peripheral wall

Claims (11)

In a valve lift control device that controls the lift amount of at least one of an intake valve and an exhaust valve of an internal combustion engine, an actuator that changes the lift amount according to the axial position of the control shaft by linearly driving a control shaft. And
A feed screw mechanism having a screw shaft that linearly moves with the control shaft in the axial direction and a rotary shaft that rotates in the circumferential direction, and that converts the rotary motion of the rotary shaft into linear motion of the screw shaft;
A case for accommodating the feed screw mechanism;
One end of the axial direction is locked by the case, and a bearing that supports the radial force of the rotating shaft,
A regulating member that engages with the other axial end of the bearing and regulates axial displacement of the bearing;
A motor stator that is locked by the case, engages with the restriction member from the opposite side of the bearing in the axial direction of the bearing, and rotates the rotation shaft by energization;
An actuator for a valve lift control device.   The actuator of the valve lift control device according to claim 1, wherein a space portion is formed around the restriction member, and elastic deformation of the restriction member is allowed by the space portion.   The actuator of a valve lift control device according to claim 2, wherein the space portion is formed on both sides of the regulating member in the axial direction of the bearing. The case has an inner peripheral wall that surrounds the outer peripheral side of the rotating shaft,
The valve according to any one of claims 1 to 3, wherein the restricting member has a fitting portion that has a shape extending in a circumferential direction of the rotating shaft and is fitted to the inner peripheral wall of the case. Actuator for lift control device. The case has an inner peripheral wall that surrounds the outer peripheral side of the rotating shaft,
The restricting member has a shape extending in the circumferential direction of the rotating shaft and is fitted to the inner circumferential wall of the case, an engaging portion to be engaged with the bearing, and the fitting portion and the engaging portion The actuator of the valve lift control device according to any one of claims 1 to 4, further comprising an elastically deformable portion that is connected to each other and is allowed to be elastically deformed.   The elastic deformation portion includes a first deformation portion disposed between the fitting portion and the bearing in a form of a double cylinder structure with the fitting portion, and the fitting portion and the first deformation portion. The actuator of the valve lift control device according to claim 5, wherein the actuator is configured by a second deformation portion that connects the two.   The actuator of the valve lift control device according to claim 5 or 6, wherein the engaging portion and the elastically deforming portion have a shape extending in the entire circumferential direction of the bearing.   The actuator of the valve lift control device according to any one of claims 4 to 7, wherein the fitting portion has a shape extending across the entire circumferential direction of the rotating shaft. The case has an inner peripheral wall that surrounds the outer peripheral side of the rotating shaft,
The motor stator has a stator core having a shape extending in a circumferential direction of the rotating shaft, and an outer peripheral portion of the stator core is engaged with the inner peripheral wall of the case and engaged with the restriction member. The actuator of the valve lift control apparatus as described in any one of Claims 1-8.   The case has a main body member having an opening and locking the bearing, and is fixed to the main body member so as to cover the opening, and is engaged with the motor stator from the side opposite to the regulating member in the axial direction of the bearing. The actuator of the valve lift control device according to any one of claims 1 to 9, wherein the actuator is combined with a mating cover member. The actuator of the valve lift control device according to claim 10, further comprising an energization circuit that is held by the cover member and energizes the motor stator.

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