JP2009119902A - Electromagnetic shock absorber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve practicability of an electromagnetic shock absorber which generates a force to the approaching/separating operation of a sprung part and an unsprung part. <P>SOLUTION: The shock absorber is structured to resiliently support a screw rod 32 to unsprung part side skeletons 70, 104 by support springs 112, 114, to support a nut 34 to sprung part side skeletons 38, 102, and to apply a turning force to the nut 34 by an electromagnetic motor 36 disposed at the sprung part side skeletons 38, 102. The screw rod 32 resiliently supported by the support springs 112, 114 is not engaged with the sprung part side skeletons 38, 102 which are the skeletons on the side of supporting the nut 34, but is engaged with the unsprung part side skeletons 70, 104 which are the skeletons on the side of supporting the screw rod 32. Rotation around an axis is thereby forbidden while permitting the axial movement of the screw rod 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electromagnetic shock absorber that generates a force with respect to an approaching / separating operation between an unsprung portion and an unsprung portion.

In recent years, electromagnetic shock absorbers that generate a force for the approach and separation of the sprung portion and the unsprung portion based on the force of the electromagnetic motor have been studied. For example, the electromagnetic shock absorber described in the following patent document Exists. According to an electromagnetic suspension device for a vehicle configured to include the electromagnetic shock absorber, it is expected as a high-performance device because of the advantage that vibration damping characteristics based on the so-called skyhook theory can be easily realized. .
JP 2006-143146 A

  The electromagnetic shock absorber described in the above patent document is a screw including a screw rod and a nut to convert the rotational force of the electromagnetic motor into a force for approaching and separating the spring upper part and the spring lower part. The mechanism is adopted. The shock absorber of the above-mentioned patent document has a structure in which a portion for holding a nut is connected via a spring and a damper and is elastically supported by a lower part of the spring. The electromagnetic shock absorber having such a structure is capable of effectively absorbing vibrations input from the wheels and transmitted to the sprung portion, in particular, relatively high frequency vibrations.

  In addition, the shock absorber described in the above patent document has a structure in which an electromagnetic motor can apply a rotational force to a screw rod, whereas a shock absorber having a structure capable of applying a rotational force to a nut has been studied. ing. In the case of a shock absorber with a structure that rotates the nut, for example, by adopting a hollow motor shaft and a structure that allows the threaded rod to pass through, etc., the shock absorber can be made compact in the axial direction or the stroke range can be increased. From this point of view, a shock absorber having a structure in which a nut is rotated is more desirable than a shock absorber having a structure in which a screw rod rotates. The electromagnetic shock absorber has been improved in various ways as described above, and it is considered that the practical use of the electromagnetic shock absorber is improved by further improvement. This invention is made | formed in view of such a situation, and makes it a subject to provide an electromagnetic shock absorber with high practicality.

  In order to solve the above-mentioned problems, an electromagnetic shock absorber according to the present invention includes a spring top side housing and a spring bottom side that are relatively unrotatable and that are relatively movable in the axial direction along with the approach and separation of the spring top and the spring bottom. The screw rod is elastically supported by a support spring on one side of the housing, and the structure is such that an electromagnetic motor can apply a rotational force to the nut supported on the other of the two housings. A mechanism is provided in which a part of the rod and a part of one of the housings are engaged with each other, and the screw rod is allowed to move in the axial direction with respect to the one while the rotation of the one is prohibited. To do.

  In the electromagnetic shock absorber of the present invention, the mechanism that prohibits the rotation around the axis while allowing the screw rod to move in the axial direction is not a housing on the side that supports the nut, but the screw rod supported by the support spring. Since the structure is engaged with the housing on the side supporting the screw rod, a relatively simple configuration and structure can be achieved. By having such advantages, the electromagnetic shock absorber of the present invention is highly practical.

Aspects of the Invention

  In the following, some aspects of the invention that can be claimed in the present application (hereinafter sometimes referred to as “claimable invention”) will be exemplified and described. As with the claims, each aspect is divided into sections, each section is numbered, and is described in a form that cites the numbers of other sections as necessary. This is merely for the purpose of facilitating the understanding of the claimable inventions, and is not intended to limit the combinations of the constituent elements constituting those inventions to those described in the following sections. In other words, the claimable invention should be construed in consideration of the description accompanying each section, the description of the embodiments, etc., and as long as the interpretation is followed, another aspect is added to the form of each section. In addition, an aspect in which some constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention. In the following items, item (1) corresponds to item 1 and items (6) to (9) correspond to items 2 to 5, respectively.

(1) An electromagnetic shock absorber that generates a force for approaching and separating the upper and lower spring parts,
A sprung-side housing and a sprung-side housing, which are respectively connected to the sprung portion and the unsprung portion, and are relatively unrotatable and relatively movable in the axial direction in accordance with the approaching and separating operation of the sprung portion and the unsprung portion
A threaded rod formed with a male thread and arranged in a posture along the axial direction;
One part of the screw rod and one part of the unsprung-side casing and one part of the unsprung-side casing are engaged with each other, and the one of the threaded rods is allowed to move in the axial direction relative to the one. A rod movement allowable rotation prohibiting mechanism that prohibits rotation with respect to
A support spring for elastically supporting the screw rod, which is allowed to move in the axial direction by the rod movement allowable rotation prohibition mechanism, on one of the spring upper side housing and the unsprung side housing;
A nut that is rotatably supported on the other of the unsprung-side housing and the unsprung-side housing and is immovable in the axial direction in a state where a female screw is formed and screwed with the screw rod;
An electromagnetic motor that is disposed on the other of the sprung-side housing and the unsprung-side housing and applies a rotational force to the nut so as to generate a force for approaching and separating the sprung portion and the unsprung portion. Equipped with electromagnetic shock absorber.

  The electromagnetic shock absorber described in this section includes a screw mechanism including a screw rod and a nut, and the screw rod is elastically supported by a support spring on one of an upper spring side housing and an unsprung side housing. It is assumed that the nut is supported by the other and the nut supported by the other of them has a structure in which a rotational force is applied by an electromagnetic motor. In the shock absorber having such a structure, it is necessary that the elastically supported screw rod be in a state in which rotation about the axis is prohibited while allowing movement in the axial direction of the screw rod. In the electromagnetic shock absorber described in this section, the mechanism for bringing the threaded rod into the state is that the part of the threaded rod and the part of the casing that supports the threaded rod are engaged with each other. The structure is configured to prohibit rotation of the casing while allowing movement in the axial direction relative to the casing. That is, the aspect of this section is a structure in which the rod movement allowable rotation prohibiting mechanism engages a part of the screw rod with a part of the housing on the side supporting the screw rod, not the case on the side supporting the nut. Therefore, a shock absorber having a relatively simple configuration and structure is realized. In addition, the "screw rod" described in this section may be only a shaft portion that is a portion in which a male screw is formed, in addition to the shaft portion, a portion provided integrally with the shaft portion, for example, It may also include a portion indicating one end of the support spring. That is, the screw rod may include other parts, members, and the like.

  As a mechanism for prohibiting rotation around the axis while allowing movement of the screw rod in the axial direction, for example, an axis line while allowing the screw rod to move in the axial direction of the nut on the side supporting the nut A shock absorber having a structure in which a holder for holding rotation in a state in which rotation is prohibited is disposed coaxially with a nut has been studied. Specifically, in addition to the thread groove, a spline groove extending in the axial direction is provided on the outer peripheral surface of the threaded rod, and the holder is slidably fitted to the threaded rod. The shock absorber having such a structure has a relatively complicated structure in which a thread groove and a spline groove intersect with each other on the outer peripheral surface of the screw rod. On the other hand, in the shock absorber according to the aspect of this section, for example, as a part of the screw rod, a part not screwed with the nut is provided in a part close to the casing on the side supporting the screw rod, and the part supports the screw rod. It is possible to have a structure that engages with a part of the housing on the side to be operated, and it is possible to have a relatively simple structure.

  The “support spring” in the aspect of this section is different from a spring provided for the purpose of supporting the vehicle weight generally provided in the suspension device, that is, a main spring that elastically connects the spring upper portion and the spring lower portion. is there. For example, the support spring can be provided mainly for the purpose of dealing with a vibration having a relatively high frequency, and the support spring also reduces an impact input from the unsprung portion and transmitted to the unsprung portion. It is possible. In addition, the thing of various structures is employable as a support spring. For example, when the absorber also includes a damper described later, a coil spring is employed so that the hydraulic damper that is a cylinder device is disposed through the coil spring (for example, in the coil spring). If configured, a compact electromagnetic shock absorber can be realized.

  The electromagnetic shock absorber according to the aspect of this section is not limited to the one that can only generate a resistance force with respect to the approaching and separating operation between the spring upper part and the spring lower part. It is also possible to generate a propulsive force that causes the spring to move relative to each other and a force that prevents the spring upper portion and the unsprung portion from moving relative to an external input. In that case, if the electromagnetic shock absorber according to the aspect of this section is used, control based on the so-called skyhook damper theory for generating damping force against sprung vibration, and control of the vehicle body for the purpose of suppressing the roll and pitch of the vehicle body. It is also possible to execute attitude control and the like.

  (2) The screw rod is elastically supported by the support spring on the unsprung-side housing as one of the unsprung-side housing and unsprung-side housing, and the unsprung-side housing and unsprung-side housing The electromagnetic shock absorber according to the item (1), wherein the nut is supported and the electromagnetic motor is disposed on the sprung side casing as the other of the above.

  According to the aspect described in this section, since the support spring is disposed between the screw rod and the unsprung-side casing, the shock that is input from the wheel and transmitted to the screw mechanism and the electromagnetic motor is reduced and vibration is generated. Can be attenuated. That is, according to the aspect of this section, the vibration transmitted to the screw mechanism and the electromagnetic motor is effectively attenuated, so that a highly reliable shock absorber is realized.

  (3) The electromagnetic shock absorber according to (1) or (2), wherein the electromagnetic motor has a hollow motor shaft that holds the nut fixedly at one end and penetrates the screw rod.

  The mode described in this section is a mode in which the structure of the electromagnetic motor is specifically limited. In the aspect described in this section, an electromagnetic motor having a hollow motor shaft is employed, and a screw rod is passed through the motor shaft, so that the shock absorber can be made compact in the axial direction. It becomes possible to plan.

(4) The electromagnetic shock absorber is
Any of (1) to (3), wherein the damper is provided in parallel with the support spring and generates a damping force for the movement of the screw rod with respect to one of the unsprung-side housing and unsprung-side housing. The electromagnetic shock absorber according to the above.

  The aspect described in this section is an aspect in which a damper is provided in parallel with the support spring, and the damper can effectively damp the relative vibration between the screw rod and the housing that supports the screw rod. . Therefore, according to the aspect of this section, for example, a shock that can effectively suppress the transmission of vibrations at the unsprung resonance frequency and its nearby frequencies from the unsprung portion to the unsprung portion by, for example, optimizing the damping coefficient of the damper. It is also possible to build an absorber.

(5) The damper is
(A) a housing that forms at least a part of one of the sprung-side housing and the unsprung-side housing and that contains the working fluid therein; (B) the housing is partitioned into two liquid chambers; A piston movable within the housing; and (C) a hydraulic fluid flow permissible mechanism that permits the flow of the hydraulic fluid between the two liquid chambers accompanying the movement of the piston in a state of imparting resistance to the flow. It is a hydraulic damper composed of
The electromagnetic shock absorber according to (4), wherein one end of the screw rod extends into the housing and is connected to the piston.

  The mode described in this section is a mode in which the damper is limited to a hydraulic damper having a structure as a cylinder device, and the screw rod functions as a piston rod of the hydraulic damper. According to the aspect of this section, the shock absorber having a simple configuration and structure is realized by integrating the piston rod of the hydraulic damper and the rod of the shock absorber. Since the shock absorber having such a structure cannot inhibit the rotation around the axis at one end of the screw rod, the rod movement allowable rotation prohibiting mechanism is effective. In the aspect of this section, the threaded rod may be composed of a single member, and the part where the male thread is formed and the part connected to the piston may be composed of separate members. The “hydraulic fluid flow permission mechanism” described in this section can be configured by, for example, an orifice, a throttle valve, or the like provided in a piston that divides two hydraulic fluid chambers.

(6) A convex portion is formed on one of the part of the screw rod and one part of the unsprung-side housing and the unsprung-side housing, and the part of the screw rod and the unsprung-side housing A recess is formed on the other of one part of the unsprung-side housing, and one of the protrusion and the recess extends in the axial direction.
The rod movement permissible rotation prohibiting mechanism slidably fits the convex portion and the concave portion to allow the axial movement of the screw rod with respect to one of the upper spring side housing and the lower spring side housing. However, the electromagnetic shock absorber according to any one of items (1) to (5), which is configured to prohibit rotation with respect thereto.

  The mode described in this section is a mode in which the structure of the rod movement allowable rotation prohibition mechanism is embodied. In this mode, for example, a key is used as the convex part and a key groove is used as the concave part, or a part of the screw rod and a part of the housing supporting it are slidably fitted by spline. The aspect etc. which were made to be employable. In addition, the shock absorber according to the aspect of this section is not limited to the above-described “convex portion” and “concave portion”, but may be provided in plural.

(7) The threaded rod is
It is configured to include a shaft portion on which a male screw is formed and an extending portion extending from the shaft portion,
The rod movement allowable rotation prohibiting mechanism engages the extension portion of the screw rod and one part of the unsprung-side housing and the unsprung-side housing, so that the unsprung side of the screw rod The electromagnetic shock absorber according to any one of (1) to (6), wherein the electromagnetic shock absorber is configured to permit rotation in the axial direction with respect to one of the housing and the unsprung-side housing while prohibiting rotation relative thereto.

  The “extending portion” described in this section refers to a portion in which one end portion is fixed to the shaft portion and extends from the shaft portion in the radial direction thereof. The extending portion may have any shape, for example, a shape formed in an annular shape having a diameter larger than the diameter of the shaft portion, a portion formed in the annular shape, and a tube extending in the axial direction from the end portion. It is possible to make it the shape etc. which combined the part formed in the shape. The housing on the side that supports the screw rod is generally shaped to have a portion that accommodates the screw rod and the support spring, and the extending portion of the screw rod is the screw rod in the housing that supports the screw rod. It becomes a location closer to the portion that accommodates the shaft portion. For example, it is easy to engage the outer peripheral surface of the extending portion and the portion of the housing that houses the screw rod. Therefore, according to the aspect of this section, it is relatively easy to engage the extension portion of the screw rod and a part of the casing supporting the screw rod with each other, and the shock absorber has a simple configuration and structure. Is realized.

  Since the shock absorber having the holding tool described above is provided coaxially with the nut, it is necessary to lengthen the screw rod by the length of the holding tool. On the other hand, according to the aspect of this section, since the extending portion extending in the radial direction is engaged with the housing on the side supporting the screw rod, the screw rod of the shock absorber having the holder is provided. In comparison, the length of the threaded rod can be shortened. As a result, for example, it is possible to shorten the axial length of the shock absorber itself, increase the stroke range of the suspension device using the axial space created by shortening the screw rod, etc. It is.

(8) The support spring is a coil spring disposed around the screw rod, one end is held by one of the spring upper side housing and the unsprung side housing, and the other end is By being held by the extension part of the screw rod,
The electromagnetic shock absorber according to item (7), wherein the extending portion of the screw rod functions as a spring seat.

  The mode described in this section is a mode in which the structure of the support spring is limited and the holding structure of the support spring is limited, and the part functioning as the spring seat of the screw rod and the part of the housing are engaged with each other. It is an aspect. According to the aspect of this section, the rod movement permissible rotation prohibiting mechanism is configured only by forming the convex portion and the concave portion described above for the shock absorber having the structure in which the spring seat of the coil spring is provided on the screw rod. Therefore, a shock absorber with a simple configuration and structure is realized.

(9) The damper is
(A) a housing that forms at least a part of one of the sprung-side housing and the unsprung-side housing and that contains the working fluid therein; (B) the housing is partitioned into two liquid chambers; A piston movable within the housing; and (C) a hydraulic fluid flow permissible mechanism that permits the flow of the hydraulic fluid between the two liquid chambers accompanying the movement of the piston in a state of imparting resistance to the flow. It is a hydraulic damper composed of
One end portion of the shaft portion of the screw rod extends into the housing and is connected to the piston,
One of the convex portion and the concave portion is formed in the extending portion of the screw rod, and the other of the convex portion and the concave portion is formed on the outer peripheral surface of the housing,
The rod movement allowable rotation prohibiting mechanism is configured to slidably fit the convex portion and the concave portion so as to prohibit the rotation of the screw rod relative to the housing while permitting the axial movement of the screw rod relative to the housing. The electromagnetic shock absorber according to item (7) or (8).

  The aspect described in this section is an aspect in which, in the aspect in which the shock absorber includes the damper, the locations where the convex portions and the concave portions are formed are limited. In this embodiment, for example, the extension portion is formed in a shape having a cylindrical portion slightly larger than the damper housing, and the inner peripheral surface of the extension portion and the outer periphery of the housing are formed. It is possible to adopt a mode in which either a convex portion or a concave portion is formed on the surface, and they are slidably fitted.

  Several embodiments of the claimable invention will now be described in detail with reference to the drawings. In addition to the following examples, the claimable invention is implemented in various modes including various modifications and improvements based on the knowledge of those skilled in the art, including the mode described in the above [Mode of Invention]. can do.

  FIG. 1 shows a vehicle suspension apparatus 10 including an electromagnetic shock absorber according to a first embodiment of the claimable invention. The suspension device 10 is an independent suspension type suspension device, and is provided on a vehicle body (upper portion of a tire housing) and a suspension lower arm 12 that holds a wheel and constitutes a part of a spring lower portion for each of the front, rear, left, and right wheels. And a mount portion 14 constituting a part of the spring top. The suspension device 10 is an integrated shock absorber and suspension spring. The suspension device 10 is mainly composed of an actuator 20 that is a main component of an electromagnetic shock absorber, and a shock absorber that includes the actuator 20 and the lower arm 12. Can be divided into a coupling mechanism 22 for coupling the two and an air spring 24 serving as a suspension spring, which are configured to include them as a component, and are integrated.

  The actuator 20 includes a screw rod 320 configured to include a shaft portion 30 formed with a male screw, and a nut 34 formed with a female screw that holds the bearing ball and is screwed with the shaft portion 30 of the screw rod 32. , An electromagnetic motor 36 (hereinafter sometimes simply referred to as “motor 36”) as a power source, and a casing 38 that accommodates the ball screw mechanism and the motor 36. The casing 38 is connected to the mount portion 14 at the outer peripheral portion.

  The motor 36 has a hollow motor shaft 40, and the motor shaft 40 is rotatably held on the casing 38 by rolling bearings 42, 44, 46. A plurality of permanent magnets 48 are fixed and arranged on the outer peripheral portion of the motor shaft 40 in the circumferential direction, and they constitute a rotor of the motor 36. A plurality of pole bodies 50 (coils having a coil wound around a core) are fixed and arranged on the inner surface of the casing 38 so as to face the permanent magnets 48, and each of these pole bodies 50 is a stator pole. As a result, they constitute a stator. With this structure, the motor 36 is a so-called DC brushless motor. A nut 34 is fixed inside the lower end of the motor shaft 40, and the motor 36 can apply a rotational force to the nut 34. Then, the screw rod 32 is screwed into the nut 34 and is disposed in a state of extending downward from the motor shaft 40. Further, the screw rod 32 extends downward from the casing 38 and is connected to the connecting mechanism 22. The screw rod 32 can be moved in the axial direction with respect to the lower arm 12 and cannot be rotated by the coupling mechanism 22. Since the structure in which the screw rod 32 is movable in the axial direction and cannot rotate with respect to the lower arm 12 will be described in detail later, the description here is reserved for the time being.

  The coupling mechanism 22 has a hydraulic damper 60. The damper 60 includes a housing 70 that stores hydraulic fluid, and a piston 72 that is fitted into the housing 70 in a liquid-tight and slidable manner. The interior of the housing 70 is partitioned into a lower chamber 74 on the lower side of the piston 72 and an upper chamber 76 on the upper side. The housing 70 is connected to the lower arm 12 via a bush 78 provided at the lower end portion thereof. On the other hand, the shaft portion 30 of the screw rod 32 of the actuator 20 extends into the housing 70, and the piston 72 is connected to the lower end portion of the shaft portion 30 of the screw rod 32. That is, the screw rod 32 is also used as a piston rod. The housing 70 and the shaft portion 30 of the screw rod 32 are in sliding contact with each other via a seal 80, and the fluid tightness of the hydraulic fluid chamber is maintained.

  The damper 60 has a structure similar to a twin tube type shock absorber, and the housing 70 includes an outer cylinder 90 and an inner cylinder 92, and a reservoir chamber 94 is formed between them. Yes. The piston 72 is fitted in the inner cylinder 92 so as to be liquid-tight and slidable. The damper 22 is allowed to flow through the hydraulic fluid between the two hydraulic fluid chambers 74 and 76 as the piston 72 moves, and is provided in the communication passage by a communication passage penetrating in the vertical direction provided in the piston 72. The throttle restricts the flow of the working fluid between the two working fluid chambers 74 and 76. Further, the base valve body 96 provided between the lower chamber 74 and the reservoir chamber 94 provides resistance to the flow of hydraulic fluid between the lower chamber 74 and the reservoir chamber 94, and the hydraulic fluid flow. It is supposed to have an allowance mechanism.

  An annular lower retainer 100 is provided on the outer periphery of the housing 70 of the damper 60. Between the lower retainer 100 and the casing 38 of the actuator 20, an outer tube 102 having an upper end fixed to the casing 38 and an inner tube fitted into the outer tube 102 and having a lower end fixed to the lower retainer 100. 104 is provided. On the other hand, the shaft portion 30 of the screw rod 32 has a floating member 108 formed in a cylindrical shape at an intermediate portion thereof fixed at the upper end thereof, and the screw rod 32 includes the floating member 108. It is composed. The floating member 108 includes a compression coil spring 112 disposed between the lower surface side of the flange portion 110 formed on the lower retainer 100 and the upper surface side of the flange portion 110 of the floating member 108 and the inner tube 104. And a compression coil spring 114 disposed between the flange portion 110 formed at the upper end portion of the coil. That is, the screw rod 32 is elastically supported by the two springs 112 and 114. The two springs 112 and 114 are juxtaposed with the damper 60 and are components of the coupling mechanism 22.

  The air spring 24 includes a chamber shell 120 coupled to the mount portion 14, an air piston cylinder 122 coupled to the lower arm 12 via the housing 70 of the damper 60, the inner tube 104, and the like, and a diaphragm 124 connecting them. It is configured to include. The lid 126 of the chamber shell 120 is connected to the casing 38 of the actuator 20 via a spring support 128 having vibration-proof rubber. The lid 126 is connected to the mount 14 via an upper support 130 having vibration-proof rubber. The lower end of the air piston cylinder 122 is fixed to the outer peripheral portion of the inner tube 104 of the cylinder 106 with the cylinder 106 accommodated therein. The diaphragm 124 has one end fixed to the lower end of the chamber shell 120 and the other end fixed to the upper end of the air piston cylinder 122. The chamber shell 120, the air piston cylinder 122, and the diaphragm 124 serve as a pressure chamber. 132 is defined. The pressure chamber 132 is filled with compressed air as a fluid. From such a structure, the air spring 24 elastically connects the lower arm 12 and the mount portion 14, that is, the spring upper portion and the spring lower portion, by the pressure of the compressed air.

  From the structure as described above, the shock absorber includes the casing 38 and the outer tube 102 to form an upper spring side casing, and the shock absorber includes the housing 70 of the damper 60 and the inner tube 104 to form an unsprung side casing. It has a structure. The spring upper side housing and the unsprung side housing cannot be rotated relative to each other, and are relatively movable in the axial direction in accordance with the approaching and separating operation between the spring upper portion and the spring lower portion. The shock absorber has a structure in which the screw rod 32 is elastically supported by the two springs 112 and 114 on the unsprung body housing as one of the unsprung body housing and the unsprung body housing. A nut 34 of the actuator 20 is supported on a spring upper side casing as the other of the upper side casing and the unsprung side casing, and a motor 36 that applies a rotational force to the nut 34 is disposed. Yes. The springs 112 and 114 function as a support spring for elastically supporting the screw rod on the unsprung side housing in cooperation with each other.

  Further, due to the structure as described above, the actuator 20 includes a nut 34, a motor 36, a casing 38 constituting an upper spring side housing, and an outer tube 102 to constitute an upper spring side unit, and the screw rod 32 is a spring. It has a structure that is a lower unit. The unsprung-side unit is connected to the mount portion 14, and the unsprung-side unit is connected to the suspension lower arm 12 via the connecting mechanism 22.

  With the structure as described above, the actuator 20 allows the screw rod 32 and the nut 34 to move relative to each other in the axial direction when the spring upper part and the spring lower part approach or separate from each other. The unit is movable relative to the unit, and the nut 34 rotates with respect to the screw rod 32 with the relative movement. Thereby, the motor shaft 40 also rotates. The motor 36 can apply a rotational torque to the nut 34, and the rotational torque generates a resistance force in a direction that prevents the relative movement between the unsprung unit and the unsprung unit. It is possible. By making this resistance force act as a damping force with respect to the relative movement between the unsprung unit and the unsprung unit, and thus with respect to the approach / separation between the unsprung portion and the unsprung portion, the actuator 20 serves as a so-called shock absorber. It is supposed to function. The actuator 20 is also capable of generating a driving force for relative movement between the unsprung side unit and the unsprung side unit. Control based on the so-called skyhook damper theory, pseudo groundhook theory, or the like. It is possible to execute. In addition, the unsprung distance between the sprung springs can be maintained at an arbitrary distance by the rotational torque of the motor 36, effectively suppressing the roll of the vehicle body when turning the vehicle, the pitch of the vehicle body when accelerating / decelerating the vehicle, etc. It is possible to adjust the height of the vehicle, the so-called vehicle height.

  If attention is paid to the vibration damping function of the actuator 30, the actuator 20 smoothly follows the vibration with a relatively low frequency of 5 Hz or less, and effective vibration with respect to such a low frequency vibration. Attenuation is possible. However, effective vibration damping is difficult for vibrations having a high frequency exceeding 10 Hz because of its followability. In the present suspension device 10, the actuator 20 and the lower arm 12 are connected by the above-described connecting mechanism 22, and even if high-frequency vibration exceeding 10 Hz is generated by the connecting mechanism 22, the lower part of the vibration is sprung from the upper part of the spring. The transmission of high-frequency vibrations to is effectively suppressed.

  Next, the structure in which the threaded rod 32 retained in the above description is movable and non-rotatable in the axial direction with respect to the lower arm 12, that is, the threaded rod 32 is moved in the axial direction with respect to the unsprung side housing. A structure that is movable and non-rotatable will be described with reference to FIGS. FIG. 2 is an enlarged front view showing the coupling mechanism 22, and FIG. 3 is a plan sectional view (A-A section in FIG. 1) showing the inside of the coupling mechanism 22. As shown in FIG. 3, four keys 140 that are convex portions are fixed to the outer peripheral surface of the housing 70 of the damper 60, and the four strips that are concave portions are formed on the inner peripheral surface of the floating member 108 that is formed in a cylindrical shape. Key groove 142 is formed. With the key 140 of the housing 70 and the key groove 142 of the floating member 108 fitted, the housing 70 is fitted into the floating member 108. With such a structure, the screw rod 32 is allowed to move in the axial direction with respect to the housing 70 and is not allowed to rotate. That is, the shock absorber according to the present embodiment allows a part of the screw rod 32 and a part of the unsprung-side housing to be engaged with each other while allowing the screw rod 32 to move in the axial direction relative to the unsprung-side housing. It is provided with a rod movement allowable rotation prohibiting mechanism that prohibits rotation relative to the housing. The floating member 108 that is a spring seat is an extending portion that extends in the radial direction from the shaft portion 30 of the screw rod 32, and the rod movement allowable rotation prohibiting mechanism is a floating member that is an extending portion of the screw rod 32. 108 and the housing 70 of the damper 60 as a part of the unsprung-side casing are engaged with each other.

  The suspension device 10 also includes a mechanism that prohibits relative movement between the sprung portion and the unsprung portion, a so-called bound stopper, and a rebound stopper. Specifically, with respect to the relative movement between the unsprung-side housing and the unsprung-side housing, the bounce stopper has an upper surface of the annular plate 150 fixed to the upper end portion of the inner tube 104 via the buffer rubber 152. The rebound stopper is configured such that the lower surface of the annular plate 150 is in contact with a flange portion formed at the lower end portion of the outer tube 102 via the buffer rubber 154. ing. Further, with respect to relative movement between the unsprung unit and the unsprung unit of the actuator 20, the bound stopper has a configuration in which the lower surface of the casing 38 comes into contact with the upper surface of the floating member 108 via the buffer rubber 156. Has been. Furthermore, the bound stopper is configured such that the upper surface of the housing 70 of the damper 60 abuts against the lower surface of the floating member 108 via the buffer rubber 158 with respect to the relative movement between the screw rod 32 and the unsprung side housing. The rebound stopper is configured such that the upper side inside the housing 70 is in contact with the upper surface of the piston 72 via the buffer rubber 160.

  As described above, the suspension device 10 is a mechanism for prohibiting rotation around the axis while allowing the screw rod 32 to move in the axial direction, and a part of the screw rod 32 and a part of the unsprung-side housing. The thing of the structure which mutually engages was employ | adopted. On the other hand, there is an apparatus having a structure like the electromagnetic suspension apparatus 180 shown in FIG. In the suspension device 180 as a comparative example, a spline groove extending in the axial direction is formed in the shaft portion 184 of the screw rod 182, and a rod holder 186 for holding a bearing ball is disposed coaxially with the nut 34 in the casing 38. Has been. The screw rod 182 and the rod holder 186 are configured to be spline-fitted so that the screw rod 182 is prevented from rotating around the axis while allowing the screw rod 182 to move in the axial direction.

If the present suspension device 10 is compared with the suspension device 180 of the comparative example, the lengths of the devices themselves are the same, but the suspension device 10 is different from the suspension device 180 of the comparative example. The stroke of the actuator 20, that is, the amount of relative movement between the screw rod 32 and the nut 34, and the stroke of the damper 60, that is, the screw rod 32, by the length L _RH of the rod holder 186 that it has The amount that can be moved relative to the unsprung-side housing is lengthened. Also, flip side, the amount corresponding to the length L _RH of the rod holder 186, we are possible to shorten the length of the suspension system 10 itself. That is, the suspension device 10 has a longer stroke and an improved vibration damping function. In addition, the shock absorber of the present embodiment is realized by providing a rod movement allowable rotation prohibiting mechanism by simply providing a convex portion and a concave portion with respect to the structure of the suspension device 180 of the comparative example. It is a shock absorber.

<Second embodiment>
5 to 7 show a vehicle suspension apparatus 200 including the electromagnetic shock absorber according to the second embodiment. FIG. 5 is a front view of the suspension device 200, FIG. 6 is an enlarged view of the coupling mechanism 202 included in the suspension device 200, and FIG. 7 is a cross-sectional view showing the inside of the coupling mechanism 202 (B in FIG. 5). -B cross section). The electromagnetic shock absorber of the present embodiment has substantially the same configuration as the shock absorber of the first embodiment except for the rod movement allowable rotation prohibiting mechanism. Therefore, in the description of the present embodiment, the description of the first embodiment will be omitted. Constituent elements having the same functions as those of the shock absorber are indicated by corresponding reference numerals, and their description is omitted or simplified.

  The screw rod 210 included in the shock absorber according to the present embodiment includes a shaft portion 212 and a floating member 214 as an extending portion, as in the first embodiment. As shown in FIG. 7, six involute-shaped teeth 222 that are convex portions are formed on the outer peripheral surface of the flange portion 220 provided thereon. On the other hand, the inner tube 224, which is a constituent element of the unsprung side housing, is formed with six grooves 226 that are recesses on the inner peripheral surface. The floating member 214 is fitted into the inner tube 224 so that the teeth 222 of the floating member 214 and the groove 226 of the inner tube 224 are engaged with each other. That is, the floating member 214 and the inner tube 224 are slidably spline-fitted. Accordingly, the shock absorber according to the present embodiment also has a part of the screw rod 210 and a part of the unsprung-side casing engaged with each other in the same manner as in the first embodiment, so that the unsprung-side casing of the screw rod 210 is engaged. It is provided with a rod movement allowable rotation prohibiting mechanism that prohibits rotation relative to the housing while allowing movement in the axial direction with respect to. The rod movement allowable rotation prohibiting mechanism has a structure in which a floating member 214 that is an extension portion of the screw rod 210 and an inner tube 224 that is a part of the unsprung side housing are engaged with each other.

If the length L _R2 of the actuator rod 210 of the suspension device 200 in the present embodiment and the length L _R0 of the actuator rod 182 of the suspension device 180 of the comparative example described in the first embodiment are compared, The actuator rod 210 of the suspension apparatus 200 is shortened by ΔL due to the absence of the rod holder 186 included in the suspension apparatus 200 of the comparative example. As a result, the length of the suspension device itself is L ₀ in the suspension device 180 of the comparative example, whereas it is L _{2 in} the suspension device 200 of the present embodiment, and is shortened by ΔL. That is, the suspension device 200 is made compact by shortening the length of the device itself. Moreover, if the reverse is turned, the stroke of the suspension device can be lengthened by the length difference ΔL as in the first embodiment.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front sectional view showing a vehicle suspension device including an electromagnetic shock absorber according to a first embodiment of the claimable invention. It is front sectional drawing which expands and shows the rod movement permissible rotation prohibition mechanism with which the electromagnetic shock absorber of 1st Example is provided. It is sectional drawing (AA cross section in FIG. 1) which shows the rod movement permissible rotation prohibition mechanism with which the electromagnetic shock absorber of 1st Example is provided. It is the figure which compared the suspension apparatus shown in FIG. 1 with the suspension apparatus comprised including the electromagnetic shock absorber of the structure already examined. It is front sectional drawing which shows the suspension apparatus for vehicles comprised including the electromagnetic shock absorber which is 2nd Example of claimable invention. It is front sectional drawing which expands and shows the rod movement permissible rotation prohibition mechanism with which the electromagnetic shock absorber of 2nd Example is provided. It is sectional drawing (BB cross section in FIG. 5) which shows the rod movement permissible rotation prohibition mechanism with which the electromagnetic shock absorber of 2nd Example is provided. FIG. 6 is a diagram comparing the suspension device shown in FIG. 5 with a suspension device including an electromagnetic shock absorber having a structure that has already been studied.

Explanation of symbols

  10: Vehicle suspension device 12: Lower arm (lower part of spring) 14: Mount part (upper part of spring) 20: Actuator 22: Connection mechanism 24: Air spring 30: Shaft part 32: Screw rod 34: Nut 36: Electromagnetic motor 38: Casing 40: Motor shaft 60: Hydraulic damper 70: Housing 72: Piston 74: Lower chamber 76: Upper chamber 94: Reservoir chamber 96: Base valve body 100: Lower retainer 102: Outer tube 104: Inner tube 108: Floating member ( 110: flange portion 112, 114: compression coil spring (support spring) 140: key (convex portion) 142: key groove (concave portion) 152-160: shock absorbing rubber 180: vehicle suspension device (ratio) Example) 182: Screw rod 184: Shaft portion 186: Rod holder 200: Vehicle suspension device 202: Connection mechanism 210: Screw rod 212: Shaft portion 214: Floating member (extending portion) 220: Flange portion 222: Teeth (convex) Part) 224: Inner tube 226: Groove (concave part)

Claims (5)

An electromagnetic shock absorber that generates a force for approaching and separating the upper and lower spring parts,
A sprung-side housing and a sprung-side housing, which are respectively connected to the sprung portion and the unsprung portion, and are relatively unrotatable and relatively movable in the axial direction in accordance with the approaching and separating operation of the sprung portion and the unsprung portion;
A threaded rod formed with a male thread and arranged in a posture along the axial direction;
One part of the screw rod and one part of the unsprung-side casing and one part of the unsprung-side casing are engaged with each other, and the one of the threaded rods is allowed to move in the axial direction relative to the one. A rod movement allowable rotation prohibiting mechanism that prohibits rotation with respect to
A support spring for elastically supporting the screw rod, which is allowed to move in the axial direction by the rod movement allowable rotation prohibition mechanism, on one of the spring upper side housing and the unsprung side housing;
A nut that is rotatably supported on the other of the unsprung-side housing and the unsprung-side housing and is immovable in the axial direction in a state where a female screw is formed and screwed with the screw rod;
An electromagnetic motor disposed on the other of the unsprung-side housing and the unsprung-side housing and imparting a rotational force to the nut so as to generate a force with respect to the approaching and separating operation of the unsprung portion and the unsprung portion; Equipped with electromagnetic shock absorber. A convex portion is formed on one of the part of the screw rod and one part of the unsprung-side casing and the unsprung-side casing, and the part of the screw rod, the unsprung-side casing and the unsprung part side. A recess is formed on the other of one part of the housing and one of the protrusion and the recess extends in the axial direction.
The rod movement permissible rotation prohibiting mechanism slidably fits the convex portion and the concave portion to allow the axial movement of the screw rod with respect to one of the upper spring side housing and the lower spring side housing. The electromagnetic shock absorber according to claim 1, wherein the electromagnetic shock absorber is configured to prohibit rotation with respect thereto. The threaded rod is
It is configured to include a shaft portion on which a male screw is formed and an extending portion extending from the shaft portion,
The rod movement allowable rotation prohibiting mechanism engages the extension portion of the screw rod and one part of the unsprung-side housing and the unsprung-side housing, so that the unsprung side of the screw rod 3. The electromagnetic shock absorber according to claim 1, wherein the electromagnetic shock absorber is configured to permit rotation in the axial direction with respect to one of the housing and the unsprung-side housing while prohibiting rotation thereof. 4. The support spring is a coil spring disposed around the screw rod, one end of which is held by one of the upper spring side housing and the lower spring side housing, and the other end of the screw rod. By being held in the extension part,
The electromagnetic shock absorber according to claim 3, wherein the extending portion of the screw rod functions as a spring seat. The damper is
(A) a housing that forms at least a part of one of the sprung-side housing and the unsprung-side housing and that contains the working fluid therein; (B) the housing is partitioned into two liquid chambers; A piston movable within the housing; and (C) a hydraulic fluid flow permissible mechanism that permits the flow of the hydraulic fluid between the two liquid chambers accompanying the movement of the piston in a state of imparting resistance to the flow. It is a hydraulic damper composed of
One end portion of the shaft portion of the screw rod extends into the housing and is connected to the piston,
One of the convex portion and the concave portion is formed in the extending portion of the screw rod, and the other of the convex portion and the concave portion is formed on the outer peripheral surface of the housing,
The rod movement allowable rotation prohibiting mechanism is configured to slidably fit the convex portion and the concave portion so as to prohibit the rotation of the screw rod relative to the housing while permitting the axial movement of the screw rod relative to the housing. The electromagnetic shock absorber according to claim 3 or claim 4 configured.

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