JP2010025139A - Suspension device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly practical suspension device for a vehicle. <P>SOLUTION: The suspension device 10 comprises: (a) an electromagnetic absorber 50 having spring upper-side units 60, 64 arranged on one axial line, and a spring lower-side unit 78, and generating an attenuating force to the relative operation of the two units; (b) springs 102, 104 elastically connecting the spring lower-side side unit and a spring lower part 36 with each other; and (c) a hydraulic damper 108 arranged between the spring lower-side unit and the spring lower part in a posture of aligning the axis of the absorber with the axis of the damper itself. The spring lower-side unit and the damper are connected by connecting mechanisms 92, 94 allowing the axial lines to incline relatively. By employing this structure, a lateral force inputted to the spring lower part is made to hardly act on the absorber to alleviate a burden on the absorber. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a suspension apparatus including an electromagnetic shock absorber that generates a damping force with respect to an approaching and separating operation between an upper part and an unsprung part.

In the field of vehicles, in recent years, an electromagnetic shock absorber (hereinafter abbreviated as “absorber”) that generates a damping force with respect to the approaching / separating operation between the sprung portion and the unsprung portion based on the force generated by the electromagnetic motor. Development of a so-called electromagnetic suspension device is being developed. The suspension device described in the following patent document is an example of the electromagnetic suspension device.
JP 2008-95800 A

  The electromagnetic absorber included in the electromagnetic suspension device has a structure that expands and contracts in its own axial direction in accordance with the approaching and separating operation of the spring upper part and the spring lower part, and generates a damping force for the expansion and contraction operation. The force input from the road surface to the unsprung part includes not only the force in the direction in which the sprung part and the unsprung part are approached and separated, but also the force in which the sprung part and the unsprung part move relatively in the lateral direction. If it acts on the absorber, it will be a heavy burden on the absorber. Suspension devices equipped with electromagnetic absorbers are still under development, so they have various problems, such as the burden on the absorber due to such lateral force, to improve practicality. It leaves a lot of room for improvement. This invention is made | formed in view of such a situation, and makes it a subject to provide a highly practical vehicle suspension apparatus.

  In order to solve the above-described problems, a vehicle suspension apparatus according to the present invention includes (a) an unsprung-side unit and an unsprung-side unit that are arranged on one axis, and allows an approach and separation operation between the unsprung portion and the unsprung portion. Along with this, the unsprung unit and unsprung unit operate relative to each other, and an electromagnetic absorber that generates a damping force for the relative operation is disposed between (b) the unsprung unit and the unsprung portion. (C) The spring is arranged between the unsprung unit and the unsprung body in such a posture that the axis of the absorber and the own axis coincide with each other, and with respect to the relative movement between the unsprung unit and the unsprung part. A suspension device for a vehicle including a hydraulic damper that generates a damping force, wherein the unsprung unit and the damper are relatively arranged such that their axes are relatively inclined. Configured to couple while allowing a change in posture.

  In the vehicle suspension apparatus according to the present invention, when a lateral force is input to the unsprung part, the axis of the damper connected to the unsprung part and the axis of the unsprung unit constituting the absorber are relatively inclined. As such, their relative posture changes are allowed. Therefore, according to the suspension device of the present invention, the lateral force input to the unsprung portion is less likely to act on the absorber, and the burden on the absorber due to such a lateral force can be reduced.

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 constituent elements are deleted from the aspect of each item can be an aspect of the claimable invention.

  In each of the following items, item (1) corresponds to claim 1, and the technical features described in item (2) are added to item 1 and item 2 (4). ) Added with the technical feature described in claim 3 is added to claim 3, and added to the technical feature described in claim 6 to claim 2 is added to claim 4 and claims 1 to 4 are added. The technical feature described in the item (8) is added to any one of the above items, the technical feature described in the item (9) is added to any one of the claims 1 to 5, and the technical feature described in the item (9) is added. This corresponds to claim 6 and the technical feature described in (10) added to any one of claims 1 to 5 corresponds to claim 7.

(1) It is configured to include a sprung unit and a sprung unit arranged on one axis, and the sprung unit is connected to the sprung portion, and the above-described approaching and separating operation between the sprung portion and the sprung portion is performed. An electromagnetic shock absorber having a structure in which the unsprung-side unit and the unsprung-side unit move relative to each other in the direction in which the axis extends and generates a damping force for the relative movement;
A spring that is disposed between the unsprung-side unit and the unsprung part and elastically allows relative movement in the direction in which the axis of the shock absorber extends between the unsprung-side unit and the unsprung part; and
Damping force with respect to relative movement between the unsprung unit and the unsprung portion, which is disposed between the unsprung unit and the unsprung portion in a posture in which the axis of the shock absorber and the own axis coincide with each other. A hydraulic damper that generates
A vehicle suspension apparatus comprising: a connection mechanism that connects the unsprung-side unit and the damper while allowing relative changes in their postures such that their axes are relatively inclined.

  An electromagnetic shock absorber (hereinafter sometimes abbreviated as "absorber") expands and contracts in the direction of its axis along with the approach and separation of the upper and lower parts of the spring and generates a damping force for the expansion and contraction. It is supposed to be a structure to let you. The absorber is disposed so as to extend substantially in the vertical direction, but not only the vertical external input but also the horizontal external input is generated in the lower part of the spring. For this reason, when such a lateral force, that is, a force that relatively moves the sprung portion and the unsprung portion in the lateral direction acts on the absorber, the lateral force becomes a force that bends the absorber, A heavy burden on the absorber. In the suspension device according to this aspect, when a lateral force is input to the unsprung part, the axis of the damper coupled to the unsprung part and the axis of the unsprung unit constituting the absorber are relative to each other. Their relative posture changes are allowed to tilt. Therefore, according to the suspension device described in this section, it is possible to make it difficult for the lateral force input to the unsprung portion to act on the absorber, and to reduce the burden on the absorber due to such lateral force. It becomes possible.

  The “electromagnetic shock absorber” described in this section is not limited to the one that can generate only a damping force. For example, a propulsive force that actively moves a spring top and a spring bottom relative to each other, It is also possible to generate a force that prevents the sprung portion and the unsprung portion from moving relative to each other. In that case, if the absorber described in this section is provided corresponding to each wheel, the purpose is to control based on the so-called skyhook damper theory that generates damping force against sprung vibration, and to suppress the roll and pitch of the vehicle body. It is also possible to execute vehicle body posture control and the like. The “spring” described in this section is for suppressing the transmission of high-frequency vibration that the operation of the electromagnetic motor cannot follow, for example, vibration in the unsprung resonance frequency range to the upper part of the spring. Therefore, it is possible to secure the riding comfort of the vehicle.

  “Spring part” described in this section broadly means, for example, a part of a vehicle body supported by a suspension spring, and “sprung part” means, for example, a component of a vehicle that moves up and down together with a wheel shaft, such as a suspension arm. Widely mean. Further, in this specification, the term “connected” mainly means that they are directly connected. However, it does not exclude being indirectly connected through any part, member, unit, or the like.

(2) The shock absorber is
(a) a screw rod that constitutes at least part of the unsprung side unit and the unsprung side unit, and is disposed in a posture in which the axis of the shock absorber and the axis of the shock coincide with each other; and (b) the spring It comprises at least a part of the upper unit and the unsprung unit, and has a nut that is screwed with the screw rod, and the relative movement between the unsprung unit and the unsprung unit A screw mechanism having a structure in which one of a screw rod and the nut rotates;
The vehicle suspension device according to item (1), further comprising: an electromagnetic motor that applies a resistance force to one rotation of the screw rod and the nut.

  Many of the electromagnetic absorbers employ a screw mechanism to convert the rotational force of the electromagnetic motor into a damping force with respect to the approaching / separating operation between the sprung portion and the unsprung portion. In an electromagnetic absorber that employs a screw mechanism, the screw rod and the nut move relative to each other in the axial direction of the absorber as the spring upper portion and the spring lower portion approach and separate. For this reason, when a lateral external input to the unsprung portion acts on the absorber, a particularly heavy burden is placed on the portion where the screw rod and the nut are screwed together. Therefore, it is preferable for the absorber that employs the screw mechanism to make it difficult for the lateral force input to the unsprung portion to act on the absorber.

(3) One of the unsprung-side unit and the unsprung-side unit has a structure that holds one of the screw rod and the nut rotatably.
One of the sprung unit and the unsprung unit, the other of the screw rod and the nut has an axial groove extending in the direction in which the axis of the shock absorber extends,
The shock absorber is
It has a fitting part that fits into the axial groove, and is non-movable and non-rotatable on one of the sprung unit and unsprung unit and the other of the screw rod and nut. The vehicle suspension according to (2), further comprising a rotation prohibiting mechanism that prohibits the other of the screw rod and the nut from moving in the direction in which the axis of the other shock absorber extends. apparatus.

  When the damper is disposed between the absorber and the unsprung part, depending on the structure of the damper, the rotation of the other of the screw rod and the nut may not be strictly prohibited. There is a possibility that the rotational force of the motor cannot be properly converted into the force in the axial direction of the absorber. In the suspension device described in this section, since the other rotation of the screw rod and the nut is prohibited, the rotational force of the electromagnetic motor can be appropriately converted to the force in the axial direction of the absorber.

  The specific structure of the “rotation prohibiting mechanism” described in this section is not particularly limited. For example, when the absorber has a structure in which the screw rod rotates, the screw rod can be rotated. A key groove (guide groove) as an axial groove is provided so as to extend in the axial direction of the absorber on one of the unit and nut to be held on the other, and a key as a fitting portion is provided on the other of them, A structure in which they are fitted may be used. Further, when the absorber has a structure in which the nut rotates, a spline groove as an axial groove is provided on the outer peripheral surface of the screw rod so as to extend in the axial direction of the screw rod, and is fitted into the spline groove. A structure may be adopted in which a spline nut is employed as the rotation prohibiting mechanism. In the absorber employing the rotation prohibiting mechanism having such a structure, when a lateral external input to the unsprung portion acts on the absorber, not only the portion where the screw rod and the nut are screwed but also the key and the key groove. This also places a heavy burden on the places where the spline nuts and spline grooves are fitted. Therefore, making it difficult for the lateral force input to the unsprung force to act on the absorber is suitable for the absorber having the rotation prohibiting mechanism.

(4) The screw rod constitutes a part of the unsprung unit.
The coupling mechanism couples the screw rod and the damper while allowing a relative inclination between the axis of the screw rod and the axis of the damper. Vehicle suspension system.

  (5) The vehicle suspension device according to (4), wherein the screw mechanism has a structure in which the nut rotates in accordance with relative movement between the unsprung unit and the unsprung unit.

(6) The nut constitutes the unsprung side unit,
The unsprung side unit has a cylindrical shape in which the nut is fixedly held at one end of the unit and one end of the screw rod is inserted, and the axis of the shock absorber and the own axis are aligned. A nut holding cylinder,
The coupling mechanism couples the nut holding cylinder and the damper while allowing a relative inclination between the axis of the nut holding cylinder and the axis of the damper (2) or (3). The vehicle suspension apparatus described in 1.

  (7) The vehicle suspension device according to (6), wherein the screw mechanism has a structure in which the screw rod rotates in accordance with relative movement between the sprung-side unit and the unsprung-side unit.

  In the suspension device described in the above four items, the structure of the coupling mechanism is specifically limited. Specifically, in the device described in the former two terms, the coupling mechanism is limited to a structure that couples the screw rod and the damper. In the device described in the latter two terms, the coupling mechanism includes a nut. It is limited to the structure which connects the nut holding cylinder to hold | maintain and a damper. According to the apparatus described in the above four items, it is possible to make it difficult to cause the lateral force input to the unsprung portion to act on the screw rod or the nut, and to the portion where the screw rod and the nut are screwed together. The burden can be reduced.

(8) The vehicle suspension device is
A tubular sprung outer shell fixedly disposed on the sprung unit in a posture that matches the axis of the shock absorber with its own axis, and a posture that matches the axis of the damper with its own axis. An unsprung outer shell disposed fixed to the damper,
One of the unsprung outer shell and the unsprung outer shell is inserted into the other, and the unsprung outer shell and the unsprung outer shell are brought into sliding contact with the approach and separation of the unsprung portion and unsprung portion. The suspension device for a vehicle according to any one of (1) to (7), wherein the suspension device is configured to move relatively.

  The suspension device described in this section is configured to expand and contract while the two outer shells are in sliding contact with each other in accordance with the relative movement of the sprung outer shell and the damper outer shell. For this reason, since the bending strength of the suspension device increases due to the sliding contact between the two outer shells, according to the suspension device described in this section, the lateral force input to the lower part of the spring further acts on the absorber. It becomes difficult and the burden on the absorber can be reduced.

(9) The coupling mechanism is
An elastic connecting body that elastically connects the unsprung unit and the damper;
The elastic coupling body is elastically deformed to allow a relative posture change between the unsprung unit and the damper such that the axis of the unsprung unit and the axis of the damper are relatively inclined. The vehicle suspension device according to any one of (1) to (8).

(10) The coupling mechanism is
A ball stud provided on one of the unsprung-side unit and the damper, and a socket provided on the other of the unsprung-side unit and the damper and rotatably holding the ball stud;
By rotating the ball stud, a relative posture change between the unsprung unit and the damper is allowed such that the axis of the unsprung unit and the axis of the damper are relatively inclined. The vehicle suspension device according to any one of (1) to (8).

  In the suspension device described in the above two sections, the specific structure of the coupling mechanism is limited, and in the apparatus described in the former section, the connection mechanism is limited to a coupling mechanism using elastic deformation of the elastic body, and the latter. In the apparatus described in the section, it is limited to a coupling mechanism using a ball joint. According to the absorber described in the above two terms, it is possible to easily allow the relative inclination of the two axes.

  In the apparatus described in the former section, since the elastic coupling body is provided between the unsprung part and the absorber, for example, high-frequency vibration that cannot be followed by the operation of the electromagnetic motor, specifically, can be said. For example, vibrations in the unsprung resonance frequency range can be absorbed not only by the spring but also by the elastic coupling body, and transmission of such high-frequency vibration to the upper part of the spring can be effectively suppressed. It becomes possible. The “elastic coupling body” described in the former section only needs to elastically connect the unsprung unit and the damper. For example, an elastic body having various structures such as a buffer rubber and a spring should be adopted. Can do.

(11) A housing in which the damper contains hydraulic fluid and is connected to the lower part of the spring, and a piston that divides the inside of the housing into two liquid chambers and is movable in the direction in which the axis of the damper extends. And a piston rod having one end connected to the piston and the other end extending from the housing,
The vehicle suspension apparatus according to any one of (1) to (10), wherein the connection mechanism connects the other end of the piston rod and the unsprung unit.

  In the suspension device described in this section, the specific structure of the damper is limited. When the coupling mechanism couples the damper having the structure described in this section and the unsprung unit, the rotation of the piston within the housing is normally allowed. May rotate around the axis, and the rotational force of the electromagnetic motor may not be properly converted to the axial force of the absorber. For this reason, the above-mentioned rotation prohibiting mechanism is often adopted for the absorber connected to the damper having the structure described in this section. Therefore, making it difficult for the lateral force input to the unsprung force to act on the absorber is suitable for the absorber connected to the damper having the structure described in this section.

  Hereinafter, some embodiments and modifications of the claimable invention will be described in detail with reference to the drawings. In addition to the following examples, the claimable invention includes various aspects in which various modifications and improvements have been made based on the knowledge of those skilled in the art, including the aspects described in the above [Aspect of the Invention] section. Can be implemented.

(A) First Example <Configuration of Vehicle Suspension Device>
FIG. 1 shows a vehicle suspension apparatus 10 of the embodiment. As shown in FIG. 2, the suspension device 10 is installed in a vehicle as one component of the independent suspension system 20. The suspension system 20 shown in FIG. 2 is a multi-link suspension system, and includes a first upper arm 30, a second upper arm 32, a first lower arm 34, a second lower arm 36, and a toe control arm 38, each of which is a suspension arm. I have. One end of each of the five arms 30, 32, 34, 36, and 38 is rotatably connected to the vehicle body, and the other end is rotatable to an axle carrier 42 that rotatably holds the wheel 40. It is connected. With these five arms 30, 32, 34, 36, and 38, the axle carrier 42 can move up and down so as to draw a substantially constant trajectory with respect to the vehicle body.

  In the suspension system 20 configured as described above, the suspension device 10 includes an electromagnetic shock absorber (hereinafter also referred to as “absorber”) 50 and an air spring 52 in parallel. More specifically, a spring absorber assembly 53 in which the absorber 50 and the air spring 52 are integrated is a mount portion 54 provided in a tire housing which is a component part of the spring upper portion and a first component portion of the spring lower portion. Two lower arms 36 are disposed.

  As shown in FIG. 1, the absorber 50 includes a generally cylindrical housing tube 60 and an electromagnetic motor 62 provided above the housing tube 60. The housing tube 60 is fixedly connected at its upper end to a motor case 64 that houses the electromagnetic motor 62, and the motor case 64 is connected to the mount portion 54 via a buffer rubber at the outer periphery thereof. It is connected.

  The electromagnetic motor 62 includes a plurality of coils 70 fixedly arranged on one circumference along the inner surface of the peripheral wall of the motor case 64, and a cylindrical motor rotatably held by the motor case 64 and the housing tube 60. The shaft 72 includes a plurality of permanent magnets 74 fixed to the outer periphery of the motor shaft 72 so as to face the coil 70. The electromagnetic motor 62 is a three-phase DC brushless motor including a stator having a coil 70 and a rotor having a permanent magnet 74.

  The absorber 50 includes, in the housing tube 60, a screw rod 78 having a thread groove 76 formed on the outer peripheral portion thereof, and a nut 80 that holds a plurality of bearing balls and is screwed with the screw rod 78. Constitutes a ball screw mechanism. The screw rod 78 is disposed in the housing tube 60 so as to extend in the vertical direction while penetrating the motor shaft 72 of the electromagnetic motor 62. On the other hand, the nut 80 is fixedly fitted to the lower end portion of the motor shaft 72 while being screwed with the screw rod 78.

  Further, the absorber 50 includes a ball spline nut (hereinafter sometimes abbreviated as “spline nut”) 82 as a rotation prohibiting mechanism that prohibits rotation of the screw rod 78 about the axis. The spline nut 82 is fixed to the lower end portion of the housing tube 60, and the threaded rod 78 passes through the spline nut 82. As shown in FIG. 3, the spline nut 82 is provided with a plurality of ball circulation paths 86, and a plurality of bearing balls 88 are held so as to circulate via the ball circulation paths 86. On the other hand, the screw rod 78 is provided with a spline groove 90 as an axial groove so as to extend in the axial direction at a position facing each of the ball circulation paths 86. The bearing ball 88 is fitted. In the present absorber 50, such a ball spline mechanism allows the screw rod 78 to move around the axis while allowing the screw rod 78 to move in the axial direction.

  The screw rod 78 is elastically connected to the upper surface of a rod support member 92 having a generally covered cylindrical shape at the lower end. More specifically, as shown in FIG. 4, a disk-like buffer rubber 94 is provided on the upper surface of the lid portion of the rod support member 92, and a disk-like thin plate 96 is provided on the upper surface of the buffer rubber 94. . In addition, a disk-shaped buffer rubber 98 is provided on the lower surface of the lid portion of the rod support member 92, and a disk-shaped thin plate 100 is provided on the lower surface of the buffer rubber 98. A hole is formed in the central portion of the buffer rubbers 94 and 98 and the thin plates 96 and 100, and a hole is also formed in the central portion of the lid portion of the rod support member 92. Bolts 101 are inserted into the holes of the lid portions of the buffer rubbers 94 and 98, the thin plates 96 and 100, and the rod support member 92, and the bolts 101 are fastened to the lower ends of the screw rods 78 so as to sandwich them. The outer diameter of the buffer rubber 94 is made larger than the outer diameter of the thin plate 96.

  As shown in FIG. 1, the rod support member 92 is fixed to the upper surface of a floating member 105 that is elastically supported by two compression coil springs 102 and 104. More specifically, the floating member 105 has a generally cylindrical shape with a lid, and a lower end portion of the floating member 105 has a flange portion 106. The compression coil spring 102 is sandwiched in a compressed state by the flange portion 106 and the upper end portion of a substantially cylindrical damper cover 110 that covers a damper 108 described later, and the compression coil spring 104 is provided between the flange portion 106 and the damper cover 110. It is clamped in a compressed state by the lower end. The floating member 105 is elastically supported by the damper cover 110 by the elastic force of the compression coil springs 102 and 104, and the rod support member 92 is fixed to the upper surface of the floating member 105.

  The damper cover 110 is fixed to the damper 108 at the lower end of the damper, specifically, to the outer periphery of a damper housing 112 (described later) which is a component of the damper cover 110, and the damper 108 is fixed to the lower end of the damper cover 110. It is connected to the second lower arm 36 via a mounting bush 114. That is, relative movement between the screw rod 78 and the unsprung portion is elastically allowed by the springs 102 and 104 disposed between the screw rod 78 and the unsprung portion. A cylindrical cover tube 115 is fixed to the lower outer peripheral surface of the housing tube 60, and a damper cover 110 is inserted from below the cover tube 115.

  The damper 108 includes a damper housing 112 that contains hydraulic fluid, a piston 116 that is fitted in the damper housing 112 in a liquid-tight and slidable manner, and one end connected to the piston 116 and the other end. The part includes a piston rod 118 extending from above the damper housing 112. The interior of the damper housing 112 is partitioned into a lower chamber 120 on the lower side of the piston 116 and an upper chamber 122 on the upper side. The piston rod 118 passes through a lid portion 124 provided on the upper portion of the damper housing 112, and is in sliding contact with the lid portion 124 through a seal. The upper end portion of the piston rod 118 is bolted to the lower surface of the lid portion of the floating member 105. That is, the floating member 105 and the rod support member 92 are fixed to the piston rod 118, and the damper 108 is configured including the floating member 105 and the rod support member 92. The piston rod 118 is arranged coaxially with the screw rod 78.

  The damper 108 has a structure similar to a twin tube type shock absorber, and the damper housing 112 includes an outer cylinder 126 and an inner cylinder 128, and a reservoir chamber 130 is formed therebetween. ing. The piston 116 is fitted in the inner cylinder 128 so as to be liquid-tight and slidable. The damper 108 is allowed to flow through the hydraulic fluid between the two hydraulic fluid chambers 120 and 122 as the piston 116 moves, and is provided in the communication passage. The throttle restricts the flow of the working fluid between the two working fluid chambers 120 and 122. On the other hand, a base valve body 132 provided between the lower chamber 120 and the reservoir chamber 130 provides resistance to the flow of hydraulic fluid between the lower chamber 120 and the reservoir chamber 130. The damper 108 generates a damping force with respect to the relative movement between the absorber 50 and the unsprung portion in the direction in which the axis of the piston rod 118 extends. That is, the axis line of the damper 108 coincides with the axis line of the piston rod 118.

  The air spring 52 includes a chamber shell 140 fixed to the mount portion 54, an air piston cylinder 142 coupled to the damper cover 110, and a diaphragm 144 connecting them. The chamber shell 140 has a generally cylindrical shape with a lid, and with the motor case 64 of the absorber 50 penetrating through a hole formed in the lid portion, a cushion rubber is interposed on the lower surface side of the mount portion 54 on the upper surface side of the lid portion. Is fixed. The lower end of the air piston cylinder 142 is fixed to the outer periphery of the damper cover 110 with the cover tube 115 accommodated therein. One end portion of the diaphragm 144 is fixed to the lower end portion of the chamber shell 140, and the other end portion is fixed to the upper end portion of the air piston cylinder 142. The chamber shell 140 and the air piston cylinder 142 are hermetically sealed by the diaphragm 144. It is connected while keeping That is, the pressure chamber 146 is defined by the chamber shell 140, the air piston cylinder 142, and the diaphragm 144. The pressure chamber 146 is connected to an air supply / discharge device that supplies compressed air to the pressure chamber 146 or discharges compressed air from the pressure chamber 146. Incidentally, since the structure of the air supply / discharge device is known, detailed description thereof is omitted.

  An annular buffer rubber 150 is adhered to the lower end portion of the housing tube 60, and an annular cushion rubber 152 is adhered to the lower end inner wall surface of the cover tube 115. An annular cushion rubber 156 is attached to the lower surface of the lid of the floating member 105.

<Function and control of vehicle suspension system>
With the structure as described above, the absorber 50 constituting the suspension device 10 includes a spring top unit connected to the mount portion 54 including the housing tube 60, the motor case 64, the nut 80, and the like, and a screw rod. The unsprung unit connected to the second lower arm 36 including 78 is configured. The unsprung-side unit and the unsprung-side unit are arranged on one axis, and are relatively movable in the direction in which the axis extends, that is, in the direction in which the axis of the absorber 20 extends. When the sprung portion and the unsprung portion are moved closer to and away from each other, the sprung unit and the unsprung unit move relative to each other, and the nut 80 and the screw rod 78 move relative to each other in the direction in which the axis of the screw rod 78 extends. The nut 80 is supposed to rotate. That is, the axis of the absorber 50 and the axis of the screw rod 78 are coincident. Further, the electromagnetic motor 62 can apply a rotational force to the nut 80, and the absorber 50 can generate a resistance force against the approaching / separating operation between the spring upper portion and the spring lower portion by the rotational force. ing. This resistance force becomes a damping force that attenuates the relative vibration between the sprung portion and the unsprung portion. In other words, the absorber 50 relies on the motor force generated by the electromagnetic motor 62 to generate a damping force with respect to the relative vibration between the sprung portion and the unsprung portion.

  As for specific control, the electromagnetic motor 62 is connected to a battery via an inverter as a drive circuit, and this inverter is connected to a control device. This control device controls the inverter to control the damping force generated by the absorber 50, and the relative vibration between the spring top and the spring bottom is damped. More specifically, a stroke sensor that detects the distance between the sprung portion and the unsprung portion is connected to the control device, and the control device is based on the sprung unsprung distance detected by the stroke sensor. The relative speed with the lower part is calculated, and the damping force to be generated is calculated according to the relative speed. The control device issues a command based on the calculated damping force to the inverter, and the inverter controls the current flowing in the electromagnetic motor 62 by controlling a switching element included in the inverter. In this way, the absorber 50 generates a damping force to be generated.

  The absorber 50 has a function of moving the spring upper part and the unsprung part closer to and away from each other and a function of maintaining the distance between the spring upper part and the unsprung part at a predetermined distance, that is, a function as an actuator. Have. Use this function to execute control based on the so-called skyhook damper theory that applies damping force according to the sprung absolute speed to the vibration of the sprung, roll of the vehicle body during turning, acceleration / deceleration It is possible to effectively suppress the pitch of the vehicle body, adjust the vehicle height, and the like.

  As described above, the absorber 50 generates an appropriate damping force by controlling the operation of the electromagnetic motor 62. However, when the frequency of relative vibration between the spring upper part and the spring lower part is increased to some extent, the operation of the electromagnetic motor 62 does not follow due to factors such as the control response of the electromagnetic motor 62 and the force generated by the absorber 50 is not. Therefore, a sufficient attenuation effect cannot be obtained. In view of this, in the suspension device 10 including the absorber 50, the unsprung unit is placed in the unsprung portion so as to effectively absorb high-frequency vibration, specifically, for example, vibration in the unsprung resonance frequency range. A damper 108 is provided which is elastically supported and generates a damping force with respect to the relative movement.

  Since the screw rod 78 serving as the unsprung side unit is elastically supported by the unsprung portion, the absorber 50 employs the ball spline mechanism as described above to prohibit the rotation of the screw rod 78 around the axis. is doing. Specifically, when the screw rod 78 and the nut 80 are relatively rotated and relatively moved, a rotational force is also applied to the screw rod 78. At this time, the bearing ball 88 held by the spline nut 82 abuts against the side wall of the spline groove 90, so that the rotation of the screw rod 78 about the axis is prohibited.

  As described above, the screw rod 78 is held so as to be relatively movable with the nut 80 and the spline nut 82, and the screw rod 78 is moved in the axial direction of the absorber 50 in accordance with the approaching and separating operation of the spring top and the spring bottom. Relative to the nut 80 and the spline nut 82. Since not only a vertical force but also a lateral force is input to the unsprung portion, when a lateral force to the unsprung portion acts on the screw rod 78, the absorber 50, in particular, the nut 80 and the spline nut 82 are applied. Is a heavy burden. In the present suspension device 10, the screw rod 78 is connected to the damper 108 via buffer rubbers 94 and 98 as elastic connecting bodies. For this reason, when a lateral force is input to the unsprung portion, the axis of the screw rod 78 and the axis of the damper 108 are relatively inclined. For this reason, such a lateral force is unlikely to act on the screw rod 78, and the burden on the nut 80 and the spline nut 82 is reduced. In other words, the suspension device 10 includes a coupling mechanism including the buffer rubbers 94 and 98, and the coupling mechanism reduces the burden on the absorber 50 due to the lateral force applied to the unsprung portion. .

  Further, when the spring upper portion and the spring lower portion are moved closer to and away from each other and the screw rod 78, the nut 80 and the spline nut 82 move relative to each other, the cover tube 115 serving as the spring upper side outer shell passes through the buffer rubber 152. Then, it slides on the outer peripheral surface of the damper cover 110 serving as the unsprung outer shell. The sliding surface of the buffer rubber 152 is relatively wide, and the bending strength of the suspension device 10 is increased by the buffer rubber 152. For this reason, even if a lateral force is input to the unsprung portion, the suspension device 10 itself is difficult to bend. Therefore, the lateral force is unlikely to act on the screw rod 78, and the nut 80 and the spline nut The burden on 82 is further reduced.

  In addition, compressed air is sealed in the pressure chamber 146 provided in the air spring 52. Due to such a structure, the air spring 52 has the second lower arm 36 and the mount portion 54, that is, by the pressure of the compressed air. The spring top and the spring bottom are elastically supported by each other. In the suspension device 10, the amount of air in the pressure chamber 146 can be adjusted by controlling the operation of an air supply / discharge device that supplies / discharges compressed air to / from the pressure chamber 146. By adjusting the amount of air, it is possible to change the vehicle height by changing the distance between the sprung portion and the unsprung portion in the vertical direction. Specifically, it is possible to increase the vehicle height by increasing the amount of air in the pressure chamber 146 and decrease the vehicle height by decreasing the amount of air.

  When the spring upper part and the spring lower part approach each other to some extent, the annular member 158 provided at the upper end of the damper cover 110 abuts against the lower surface of the housing tube 60 via the buffer rubber 150 or the housing tube 60 The lower end portion of the rod is in contact with the upper surface of the rod support member 92 via the buffer rubber 94. That is, the shock absorbing rubber 94 as the connecting mechanism also functions as a bound stopper. On the other hand, when the spring upper portion and the spring lower portion are separated to some extent, the annular member 158 abuts against the flange portion formed at the lower end portion of the cover tube 115 via the buffer rubber 152 or the lid portion of the damper housing 112. The upper surface of 124 is brought into contact with the lower surface of the lid portion of the floating member 105 via the buffer rubber 156.

<Modification>
In the suspension device 10, the screw rod 78 is elastically connected to the rod support member 92 via the buffer rubbers 94 and 98. However, the screw rod 78 and the rod support member 92 are connected by a ball joint. May be. Specifically, as shown in FIG. 5, a ball stud 160 having a ball portion is fixed to the lower end portion of the screw rod 78, and the ball portion of the ball stud 160 is rotatably held within itself. The socket 162 may be fixed to the lid portion of the rod support member 92. As described above, by connecting the screw rod 78 and the rod support member 92, when a lateral external input is generated in the lower part of the spring, the ball portion of the ball stud 160 is rotated in the socket 162, and the screw The axis of the rod 78 and the axis of the damper 108 are relatively inclined. For this reason, the external input in the lateral direction is less likely to act on the screw rod 78, and the burden on the nut 80 and the spline nut 82 can be reduced. That is, even if the screw rod 78 and the damper 108 are connected by the connecting mechanism including the ball stud 160 and the socket 162, it is possible to reduce the load on the absorber 50 due to the lateral force applied to the unsprung portion. It becomes.

(B) Second Embodiment FIG. 6 shows a vehicle suspension apparatus 170 according to a second embodiment. The absorber 50 provided in the suspension device 10 of the previous embodiment has a structure in which the nut rotates, whereas the absorber 172 provided in the suspension device 170 has a structure in which the screw rod rotates. Since the suspension device 170 includes many components that are substantially the same as those of the suspension device 10 of the previous embodiment, the same reference numerals are used for the components having the same functions, and the description is omitted or simplified. .

  The absorber 172 is arranged in parallel with the air spring 180, and the spring absorber assembly 182 composed of the absorber 172 and the air spring 180 is similar to the previous spring absorber assembly 52 and the second mounting portion 54. It is arranged between the lower arm 36. The absorber 172 includes a generally cylindrical upper tube 184 and a lower tube 186 that fits into the upper tube 184 and projects downward from the lower end of the upper tube 184. The upper tube 184 is fixedly connected to the motor case 190 that houses the electromagnetic motor 188 at the upper end of the upper tube 184, and the motor case 190 is attached to the mount portion 54 via a buffer rubber at the outer periphery thereof. It is connected.

  The electromagnetic motor 188 includes a plurality of coils 192 that are fixedly arranged on one circumference along the inner surface of the peripheral wall of the motor case 190, a hollow motor shaft 194 that is rotatably held by the motor case 190, A permanent magnet 196 is provided that is fixed to the outer periphery of the motor shaft 194 so as to face the coil 192. The electromagnetic motor 188 is a motor in which the coil 192 functions as a stator and the permanent magnet 196 functions as a rotor, and is a three-phase DC brushless motor.

  The absorber 172 includes a screw rod 200 as a male screw portion in which a thread groove is formed, and a nut 202 as a female screw portion that holds the bearing ball and is screwed with the screw rod 200, and these have a ball screw mechanism. It is composed. The screw rod 200 is fixed to the motor shaft 194 at the upper end of the screw rod 200 in a state of passing through the motor shaft 194 of the electromagnetic motor 188, and is disposed in the upper tube 184 so as to extend in the vertical direction. On the other hand, the nut 202 is fixedly supported on the upper end portion of the lower tube 186 as a nut holding cylinder while being screwed with the screw rod 200. The upper tube 194 is provided with a pair of guide grooves 204 as axial grooves extending in the vertical direction on the inner wall surface thereof, and each of the guide grooves 204 has an upper end of the lower tube 186. Each of a pair of keys 206 as a fitting portion attached to the portion is fitted, and the upper tube 184 and the lower tube 186 are not relatively rotatable by the guide groove 204 and the key 206, and The relative movement in the vertical direction is possible.

  The lower tube 186 is elastically fixed to the upper surface of a tube support member 210 having a generally covered cylindrical shape at the lower end. More specifically, a disk-shaped buffer rubber 212 is provided on the upper surface of the lid portion of the tube support member 210, and a disk-shaped buffer rubber 214 is provided on the lower surface of the lid portion of the tube support member 210. A disk-shaped thin plate 216 is provided on the lower surface of 214. A hole is made in the center of the buffer rubbers 212 and 214 and the thin plate 216, and a hole is also made in the center of the lid of the tube support member 210. A bottom member 218 having a hole in the center is fixed to the lower end of the lower tube 186. Bolts 220 are inserted into the holes of the buffer rubbers 212 and 214, the thin plate 216, the bottom member 218, and the tube support member, and the bolts 220 and the nuts 222 are fastened so as to sandwich them.

  The tube support member 210 is fixed to the upper surface of a generally disk-shaped floating member 230. Like the floating member 105 of the previous embodiment, the floating member 230 is elastically supported by two compression coil springs 234 and 236 in a state of being included in a substantially cylindrical damper cover 232 that covers the damper 108. ing. The damper cover 232 is fixed to the outer periphery of the damper housing 112 constituting the damper 108 at its lower end, and the damper 108 is attached to the second lower arm 36 via the mounting bush 114 at its lower end. It is connected. Further, the upper end portion of the piston rod 118 constituting the damper 108 is bolted to the lower surface of the floating member 230. That is, the floating member 230 and the tube support member 210 are fixed to the piston rod 118, and the damper 108 is configured including the floating member 230 and the tube support member 210.

  The air spring 180 includes a chamber shell 140 fixed to the mount portion 54, and a diaphragm 240 that connects the chamber shell 140 and the damper cover 232. One end portion of the diaphragm 240 is fixed to the lower end portion of the chamber shell 140, and the other end portion is fixed to the upper end portion of the damper cover 232, and the chamber shell 140 and the damper cover 232 are kept airtight by the diaphragm 240. Connected. That is, a pressure chamber 242 is defined by the chamber shell 140, the damper cover 232, and the diaphragm 240, and compressed air is supplied to or discharged from the pressure chamber 242 by an air supply / discharge device. The height is changed.

  An annular buffer rubber 244 is attached to the upper surface of the flange portion formed at the upper end of the damper cover 232, and an annular buffer rubber 246 is attached to the lower surface of the flange cover 232. An annular cushion rubber 248 is attached to the lower surface.

  In the present suspension device 170, since the lower tube 186 as a nut holding cylinder is connected to the damper 108 via the buffer rubbers 212 and 214, when a lateral force is input to the lower part of the spring, The axis of the lower tube 186 and the axis of the damper 108 are relatively inclined. For this reason, such a lateral force is unlikely to act on the nut 202, and the burden on the screw rod 200 and the nut 202 is reduced. That is, the suspension device 170 includes a coupling mechanism including the buffer rubbers 212 and 214, and the coupling mechanism reduces the burden on the absorber 172 due to the lateral force applied to the unsprung portion. .

  Further, when the spring upper portion and the spring lower portion approach and separate from each other and the screw rod 200 and the nut 202 move relative to each other, the damper cover 232 as the damper outer shell is moved through the buffer rubbers 244 and 246 to the spring upper portion. It slides on the outer peripheral surface of the upper tube 184 as a side outer shell. The sliding surfaces of the two buffer rubbers 244 and 246 are relatively wide, and the bending strength of the suspension device 170 is increased by the two buffer rubbers 244 and 246. For this reason, even if a lateral force is input to the unsprung portion, the lateral force is less likely to act on the nut 202, and the burden on the screw rod 200 and the nut 202 is further reduced.

  When the spring upper part and the spring lower part approach to some extent, the flange part formed at the upper end part of the upper tube 184 contacts the flange part at the upper end part of the damper cover 232 via the buffer rubber 244, or An annular member 250 provided at the lower end portion of the upper tube 184 is brought into contact with the upper surface of the tube support member 210 via a buffer rubber 212. That is, the buffer rubber 212 as the coupling mechanism also functions as a bound stopper. On the other hand, when the spring upper portion and the spring lower portion are separated to some extent, the annular member 250 abuts against the flange portion at the upper end portion of the cover tube 232 via the buffer rubber 246 or the upper surface of the lid portion 124 of the damper housing 112. Is brought into contact with the lower surface of the floating member 230 via the buffer rubber 248.

1 is a cross-sectional view showing a vehicle suspension apparatus according to a first embodiment of the claimable invention. It is a figure which shows the suspension system by which the vehicle suspension apparatus of FIG. 1 was arrange | positioned. It is a figure which shows the structure of the rotation prohibition mechanism with which the suspension apparatus for vehicles of FIG. 1 is provided. It is a figure which shows the structure of the connection part of the screw rod and damper with which the suspension apparatus for vehicles of FIG. 1 is provided. It is sectional drawing which shows the suspension apparatus for vehicles which is a modification of claimable invention. It is sectional drawing which shows the suspension apparatus for vehicles which is 2nd Example of claimable invention.

Explanation of symbols

  10: Vehicle suspension device 36: Second lower arm (unsprung part) 50: Electromagnetic shock absorber 54: Mount part (sprung part) 60: Housing tube (sprung part unit) 62: Electromagnetic motor 64: Motor case (sprung part) 78: Screw rod (screw mechanism) (unsprung unit) 80: Nut (screw mechanism) (unsprung unit) 82: Ball spline nut (rotation prohibition mechanism) 88: Bearing ball (fitting part) 90 : Spline groove (axial groove) 94, 98: Buffer rubber (elastic coupling body) (coupling mechanism) 102, 104: Compression coil spring (spring) 108: Damper 110: Damper cover (outer spring side outer shell) 112: Damper housing (Housing) 1 5: Cover tube (spring upper side outer shell) 116: Piston 118: Piston rod 160: Ball stud (connection mechanism) 162: Socket (connection mechanism) 170: Vehicle suspension 172: Electromagnetic shock absorber 184: Upper tube (spring) 186: lower tube (nut holding cylinder) 188: electromagnetic motor 200: screw rod (screw mechanism) (spring upper side unit) 202: nut (screw mechanism) (spring lower side unit) 204: guide groove (shaft) 206): Key (rotation prohibition mechanism) (fitting part) 212, 214: Buffer rubber (elastic coupling body) (coupling mechanism) 232: Damper cover (outer spring side outer shell) 234, 236: Compression coil spring (spring) )

Claims (7)

An unsprung unit and an unsprung unit arranged on one axis are configured, and the unsprung unit is connected to the unsprung portion, and the axis extends as the approaching and separating operation of the unsprung and unsprung portions is performed. An electromagnetic shock absorber having a structure in which the unsprung-side unit and the unsprung-side unit move relative to each other and generates a damping force for the relative movement;
A spring that is disposed between the unsprung-side unit and the unsprung part and elastically allows relative movement in the direction in which the axis of the shock absorber extends between the unsprung-side unit and the unsprung part; and
Damping force with respect to relative movement between the unsprung unit and the unsprung portion, which is disposed between the unsprung unit and the unsprung portion in a posture in which the axis of the shock absorber and the own axis coincide with each other. A hydraulic damper that generates
A vehicle suspension apparatus comprising: a connection mechanism that connects the unsprung-side unit and the damper while allowing relative changes in their postures such that their axes are relatively inclined. The shock absorber is
(a) a screw rod that constitutes at least part of the unsprung side unit and the unsprung side unit, and is disposed in a posture in which the axis of the shock absorber and the axis of the shock coincide with each other; and (b) the spring It comprises at least a part of the upper unit and the unsprung unit, and has a nut that is screwed with the screw rod, and the relative movement between the unsprung unit and the unsprung unit A screw mechanism having a structure in which one of a screw rod and the nut rotates;
The vehicle suspension device according to claim 1, further comprising: an electromagnetic motor that applies resistance to one rotation of the screw rod and the nut. The screw rod constitutes a part of the unsprung unit.
The vehicle suspension device according to claim 2, wherein the connection mechanism connects the screw rod and the damper while allowing a relative inclination between the axis of the screw rod and the axis of the damper. The nut constitutes the unsprung unit,
The unsprung side unit has a cylindrical shape in which the nut is fixedly held at one end of the unit and one end of the screw rod is inserted, and the axis of the shock absorber and the own axis are aligned. A nut holding cylinder,
The vehicle suspension according to claim 2, wherein the connecting mechanism connects the nut holding cylinder and the damper while allowing a relative inclination between an axis of the nut holding cylinder and an axis of the damper. apparatus. The vehicle suspension device is
A tubular sprung outer shell fixedly disposed on the sprung unit in a posture that matches the axis of the shock absorber with its own axis, and a posture that matches the axis of the damper with its own axis. An unsprung outer shell disposed fixed to the damper,
One of the unsprung outer shell and the unsprung outer shell is inserted into the other, and the unsprung outer shell and the unsprung outer shell are brought into sliding contact with the approach and separation of the unsprung portion and unsprung portion. 5. The vehicle suspension device according to claim 1, wherein the vehicle suspension device is configured to be relatively operated. The coupling mechanism is
An elastic connecting body that elastically connects the unsprung unit and the damper;
The elastic coupling body is elastically deformed to allow a relative posture change between the unsprung unit and the damper such that the axis of the unsprung unit and the axis of the damper are relatively inclined. The vehicle suspension device according to any one of claims 1 to 5, wherein the suspension device is a vehicle suspension device. The coupling mechanism is
A ball stud provided on one of the unsprung-side unit and the damper, and a socket provided on the other of the unsprung-side unit and the damper and rotatably holding the ball stud;
By rotating the ball stud, a relative posture change between the unsprung unit and the damper is allowed such that the axis of the unsprung unit and the axis of the damper are relatively inclined. The vehicle suspension device according to any one of claims 1 to 5.

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