JP2009184595A - Suspension device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a suspension device enhanced in reliability and capable of improving the riding comfortableness of a vehicle. <P>SOLUTION: This suspension device S includes: an actuator A having a motion converting mechanism T for converting a linear motion to a rotating motion and a motor M connected to a rotating member 1 which performs the rotating motion of the motion converting mechanism T; and a hydraulic pressure damper D connected to a linear motion member 2 which performs the linear motion of the motion converting mechanism T. The suspension device further includes: an outer tube 27 connected to the actuator A; and a bearing 34 attached to a rod 31 or a cylinder 32 connected to the linear motion member 2 of the hydraulic pressure damper D and brought into slidable contact with the outer tube 27. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a suspension device that suppresses relative movement between the vehicle body and an axle by electromagnetic force generated in a motor.

This type of suspension device includes a suspension spring that elastically supports a vehicle body, that is, a sprung member of a vehicle, a screw shaft that is rotatably engaged with a ball screw nut that is connected to an axle, that is, an unsprung member, and one end of the screw shaft. And an actuator including a motor interposed between a pair of springs and elastically supported by the sprung member, and a hydraulic damper that is fixed to the sprung member and attenuates vibration in the vertical direction of the actuator. There is one that actively controls the relative movement between the vehicle body and the axle with the thrust (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 08-197931 (paragraph number 0023, FIG. 1)

  As described above, in the case of a conventional suspension device, a motion conversion mechanism including a screw shaft and a ball screw nut that converts a torque of a motor that is a damping force generation source into a damping force that should be applied in a linear direction is provided. In addition, since the inertial mass of the rotating member is large, the motor and motion conversion mechanism cannot expand and contract due to the friction of the rotating system when high-frequency vibration is input. Therefore, the above-described hydraulic damper and the pair of springs absorb the high-frequency vibration. Like to do.

  However, in this suspension device, an annular bearing is interposed at two locations between the outer cylinder covering the motor and the motor in order to guide the linear motion of the motor, so that the hydraulic damper and the motor are sandwiched. Even if it is intended to absorb high-frequency vibration with a spring, the presence of the bearing makes it difficult for the hydraulic damper to move, impeding vibration absorption, and transmitting vibration to the sprung member, which may result in poor ride comfort in the vehicle. is there.

  In addition, since the bearing prevents the motor from moving up and down, a large acceleration is likely to act on the actuator, and when high-frequency vibration is input, each part of the actuator is directly vibrated by the high-frequency vibration. There is a problem in terms of the reliability of the shock absorber.

  Accordingly, the present invention has been made in consideration of the above-described problems, and an object of the present invention is to provide a suspension device that can improve reliability and riding comfort in a vehicle.

  In order to achieve the above object, an actuator including a motion conversion mechanism that converts linear motion into rotational motion, a motor coupled to a rotating member that exhibits rotational motion in the motion conversion mechanism, and linear motion in the motion conversion mechanism. In a suspension device comprising a fluid pressure damper connected to a linear motion member to be exhibited, an outer cylinder connected to the actuator and a rod or cylinder connected to the linear motion member of the fluid pressure damper are attached to the inner cylinder of the outer cylinder. A bearing that is in sliding contact with the circumference is provided.

  According to the suspension device of the present invention, the bearing is in sliding contact with the inner periphery of the outer cylinder and functions as a bearing for the entire expansion and contraction of the suspension device, but this bearing is only a fluid pressure damper that absorbs high-frequency vibrations. For the expansion and contraction of the outer cylinder, the bearing does not move up and down in the axial direction, so that the bearing does not give resistance to the expansion and contraction of the fluid pressure damper.

  In other words, the bearing is in sliding contact with the location that does not affect the expansion and contraction of the fluid pressure damper, and the smooth expansion and contraction of the fluid pressure damper is compensated. The fluid pressure damper is expanded and contracted to absorb vibrations, thereby improving the vibration insulation of the sprung member and improving the ride comfort in the vehicle.

  Furthermore, since the bearing does not hinder the expansion and contraction of the fluid pressure damper with respect to the input of high frequency vibration, it is possible to protect the motor and the motion conversion mechanism by suppressing the impact force directly acting on the actuator, and the suspension device The reliability of the actuator, which is the main component of the suspension, can be improved, and the reliability of the suspension apparatus can be improved by solving the problems of the conventional suspension apparatus.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a longitudinal sectional view of a suspension device according to an embodiment.

  As shown in FIG. 1, a suspension device S according to an embodiment basically includes a motion converting mechanism T that converts linear motion into rotational motion, and a ball screw that is a rotating member that exhibits rotational motion in the motion converting mechanism T. An actuator A including a motor M coupled to the nut 1, a hydraulic damper D coupled to the screw shaft 2, which is a linear member that exhibits linear motion in the motion conversion mechanism 2, and an external coupled to the actuator A The cylinder 27 and an annular bearing 34 that is attached to a rod 31 connected to the screw shaft 2 that is a linear motion member of the fluid pressure damper D and that is in sliding contact with the inner periphery of the outer cylinder 27 are configured.

  The suspension device S is capable of linearly moving the screw shaft 2 in the vertical direction in FIG. 1 by rotating the ball screw nut 1 with the torque generated by the motor M, and functions as an actuator. it can.

  Further, when the screw shaft 2 is forcibly linearly moved by an external force, the rotor R of the motor M exhibits a rotational motion, and the motor M generates a torque that suppresses the rotational motion of the rotor R caused by the induced electromotive force. It functions to suppress the linear motion of the shaft 2. In other words, in this case, the vertical axis in FIG. 1 of the screw shaft 2 that is a member on the linear motion side is a regenerative torque generated by regenerating the kinetic energy input from the outside by the motor M into electric energy. It suppresses movement.

  That is, the suspension device S can apply a thrust to the screw shaft 2 by positively generating torque in the motor M, and if the screw shaft 2 is forced to move by an external force, the motor The linear motion of the screw shaft 2 can be suppressed by the regenerative torque generated by M.

  Therefore, the suspension device S not only generates a damping force that suppresses the linear motion of the screw shaft 2 but also functions as an actuator. Therefore, the suspension device S is connected to the vehicle body, the axle, and the vehicle. In the case of being used in between, the posture control of the vehicle body of the vehicle can be performed at the same time, thereby functioning as an active suspension.

  In this suspension device S, a fluid pressure damper D is connected in series to the screw shaft 2 of the actuator A connected to the sprung member, and this fluid pressure damper D is provided mainly for the purpose of absorbing high-frequency vibrations. It has been. That is, the fluid pressure damper D is connected in series with the actuator A that has a large moment of inertia and does not easily expand and contract with respect to the input of the high-frequency vibration and easily transmits the vibration. This vibration energy is absorbed with respect to the input.

  As described above, the suspension device S can effectively suppress vibration not only for low-frequency vibration but also for input of high-frequency vibration caused by riding on a protrusion on a road surface, and can improve riding comfort in a vehicle. It can be done.

 The screw shaft 2 will be described in detail below. The screw shaft 2 is formed in a cylindrical shape as shown in FIG. 1, and a spiral screw groove (not shown) is formed on the outer periphery of the screw shaft 2, and along the axis, that is, the screw shaft. A straight spline groove (not shown) is formed along the two linear motion directions. Note that the spline groove may not be formed at the final ends on both sides of the screw shaft 2 in order to prevent the screw shaft 2 from falling off a ball spline nut 3 described later, and a spline groove is provided. The number may be arbitrary.

  On the other hand, the ball screw nut 1 which is a screw nut is well known and not shown in detail, but a spiral passage facing the screw groove of the screw shaft 2 provided on the inner periphery of the cylindrical body, and the inside of the cylindrical body. A circulation path that communicates with both ends of the passage, a plurality of balls that are accommodated in the passage and the circulation path, and that run through the screw groove 2, and a spacer that is interposed between the balls. Each ball can circulate through the loop-shaped passage and the circulation path. In this embodiment, a screw nut is used as a ball screw nut 1 to realize a smooth linear motion of the screw shaft 2. However, a screw thread that is simply screwed into a screw groove of the screw shaft 2 is provided. It may be a nut. An annular groove 1a is provided on the outer periphery of the ball screw nut 1, and a cylindrical socket 1b is provided at the upper end in FIG.

  Subsequently, since the screw shaft 2 is linearly moved by the rotational drive of the ball screw nut 1, a detent mechanism for the screw shaft 2 is required. In this embodiment, a spline provided on the outer periphery of the screw shaft 2 is required. The groove and the ball spline nut 3 constitute the rotation preventing mechanism. Although this ball spline nut 3 is well known and not shown in detail, a linear passage facing the spline groove provided on the outer periphery of the screw shaft 2 provided on the inner periphery of the cylindrical main body, and the inside of the cylindrical main body. Provided with a circulation path that communicates with both ends of the passage, a plurality of balls that are accommodated in the passage and the circulation path and travel through the spline grooves, and a spacer that is interposed between the balls. Each ball can circulate through the loop-shaped passage and the circulation path. A key groove 3 a is provided on the side of the ball spline nut 3.

  A ball screw nut 1 is screwed onto the screw shaft 2 along the screw groove, and a ball spline nut 3 is inserted into the screw shaft 2 along the spline groove.

  Further, the ball screw nut 1 and the ball spline nut 3 are both held on the inner periphery of the cylindrical holder 5 with the ball screw nut 1 in the upper side in FIG.

  The holder 5 has a cylindrical shape, and a plurality of nut portions 5a having screw holes provided so as to protrude to the outer periphery of the upper end in FIG. 1, and a flange 5b that protrudes inward from the inner periphery of the lower end in FIG. 1, a step portion 5c provided in the middle portion of the inner periphery, a mounting portion 5d to which the anti-vibration rubber 21 composed of a pair of annular protrusions provided in the middle portion of the outer periphery is mounted, and a lower portion in FIG. 1 from the step portion 5c. And a keyway 5e provided on the inner periphery.

  The ball spline nut 3 is fitted on the inner periphery of the holder 5 and below the stepped portion 5c, and is provided on the key groove 3a provided on the outer periphery of the ball spline nut 3 and the inner periphery of the holder 5. The key 6 is inserted into the keyway 5e, and is held in a state in which the holder 5 is prevented from rotating.

  The ball spline nut 3 is held between a snap ring 7 that is in contact with the upper end of the ball spline nut 3 in FIG. 1 and is attached to the inner periphery of the holder 5 and a flange portion 5 b of the holder 5. Is prevented from falling off.

  Further, the ball screw nut 1 is sandwiched between a step portion 5 c provided on the inner periphery of the holder 5 and a nut 8 that is screwed to the inner periphery of the holder 5, via a ball bearing 9 that is fixed to the inner periphery of the holder 5. The holder 5 is rotatably held. The ball 9a of the ball bearing 9 travels in an annular groove 1a formed on the outer periphery of the ball screw nut 1. The ball screw nut 1 itself functions as an inner ring of the ball bearing 9, and the holder 5 The ball screw nut 3 can be fixed to the holder 5 by fixing the outer ring 9 b of the ball bearing 9. The ball screw nut 1 and the ball spline nut 3 are arranged close to each other while being held by the holder 5.

  That is, the motion conversion mechanism T composed of the ball screw nut 1 and the screw shaft 2 is held by the holder 5 in a state in which the screw shaft 2 is prevented from rotating and is assembled, and the ball screw nut 1 rotates. When the screw shaft 2 is stopped by the ball spline nut 3, the screw shaft 2 exhibits a linear motion in the vertical direction in FIG.

  In the case of the present embodiment, as described above, the ball screw nut 1 and the screw shaft 2 in the motion conversion mechanism T and the ball spline nut 3 as a rotation prevention mechanism for the screw shaft 2 are provided with one holder 5 as described above. By holding, these are assembled in a state where the screw shaft 2 and the ball screw nut 1 are aligned, so that the operation of the motion conversion mechanism T is guaranteed.

  Accordingly, the shaft 17 of the motor M, the screw shaft 2 and the shaft core of the ball screw nut 1 are brought into alignment with each other by the holder 5 and the motor M is fixed to the holder 5. Since no load is applied to the ball as the thread of the screw nut 1 and no radial load is applied to the shaft 17 of the motor M, the life of the actuator A is not shortened and the durability of the suspension device S is reduced. I will not let you.

  Further, since the shaft 5 of the motor M, the screw shaft 2 and the axis of the ball screw nut 1 are brought into alignment by the holder 5, the screw shaft 2 and the ball screw nut 1 are aligned at the time of mounting on the vehicle. Since no work is required, the mounting work on the vehicle is greatly facilitated as compared with the conventional suspension device.

  Further, if the screw shaft 2 and the ball screw nut 1 are assembled by the holder 5 and the motor M is connected to the assembly, the assembly of the actuator A is completed, so that the assembly process in the actuator A portion of the suspension device S is facilitated.

  That is, in the motion conversion mechanism T, a member that exhibits rotational motion, in this case, the ball screw nut 1 is not held by the holder 5 but is adopted to be incorporated on the motor M side, the motion conversion with the motor M is performed. When the mechanism T is connected, it is necessary to rotate the ball screw nut 1 and pull the screw shaft 2 into the motor M. In this way, the holder 5 integrally holds all of the motion conversion mechanism T. In the case of adopting a configuration in which the ball screw nut 1, the screw shaft 2, and the ball spline nut 3 are respectively held by separate holders without the ball screw nut 1 being incorporated into the motor M. However, there is an advantage that such consideration is not necessary, although it is necessary to consider the detent between the holders.

  The advantages of holding the ball screw nut 1, the screw shaft 2, and the ball spline nut 3 with one holder 5 have been described above. However, the ball screw nut 1, the screw shaft 2, and the ball spline nut 3 are held with separate holders, respectively. This is not to prevent the adoption of such a configuration.

  Returning, the ball screw nut 1 provided for driving in the axial direction of the screw shaft 2 and the ball spline nut 3 which is a component of the rotation prevention mechanism of the screw shaft 2 are arranged close to each other. The length of the screw shaft 2 located in the section between the ball spline nut 3 can be shortened.

  The portion of the screw shaft 2 located in the section is a portion where twisting occurs due to the rotational drive of the ball screw nut 1. The shorter the section, the shorter the portion where twisting occurs.

  Here, since the screw shaft 2 also functions as a spring element by twisting, the longer the twisting section, the longer the response of the linear motion of the screw shaft 2 to the rotation of the ball screw nut 1 takes. As described above, the ball screw nut 1 and the ball spline nut 3 are arranged close to each other, so that the section where the screw shaft 2 is twisted can be shortened. Therefore, the responsiveness when the suspension device S functions as an actuator is improved. Will improve.

  Therefore, since the responsiveness when the suspension device S functions as an actuator is improved, the controllability when the vehicle attitude is actively controlled is also improved.

  On the other hand, as shown in FIG. 1, the motor M is composed of a top cylindrical casing 10, a core 11 a that is an armature core fixed to the inner periphery of the casing 10, and a coil 11 b that is wound around the core 11 a. 1, an annular cap 12 that fits into the lower end opening in FIG. 1 of the casing 10, and a cylindrical sensor that holds the resolver stator 13 a on the inner periphery that is housed and fixed on the inner periphery of the top side of the casing 10. The holder 13 includes a ball bearing 14 fixed to the inner periphery of the sensor holder 13 and a rotor 16 rotatably accommodated in the casing 10 via a ball bearing 15 fixed to the inner periphery of the cap 12. . The cap 12 includes a cylindrical portion 12a that fits to the inner periphery of the casing 10, a flange portion 12b that is provided on the outer periphery of the cylindrical portion 12a and that abuts on a flange 10a that is provided on the outer periphery of the lower end in FIG. A cylindrical fitting portion 12 c that is suspended from the cylindrical portion 12 a and is fitted to the inner periphery of the upper end of the holder 5 is configured.

 The rotor 16 includes a cylindrical shaft 17 and a magnet 18 attached to the outer periphery of the intermediate portion of the shaft 17 so as to face the core 11a. The upper end of the shaft 17 is the inner side of the ball bearing 14 described above. The lower end is pivotally supported by the inner periphery of the ball bearing 15 and is rotatably accommodated in the casing 10. The magnet 18 is formed such that a plurality of magnets are bonded together so that the N pole and the S pole appear alternately along the circumference, so that the N pole and the S pole are along the circumference. Annular magnets having split magnetic pole patterns that appear alternately may be used.

  Therefore, in this embodiment, the motor M is configured as a brushless motor. However, various types of motors M can be used as the motor M. Specifically, for example, direct current, alternating current can be used. A motor, an induction motor, a synchronous motor, or the like can be used.

  A resolver core 13b is attached to the rotor 16 at a position that is fixed to the inner periphery of the sensor holder 13 and is opposed to the resolver stator 13a on the outer periphery of the shaft 17, and the rotor is driven by the resolver stator 13a and the resolver core 13b. The rotational position of the rotor 16 can be detected, and the motor M can be controlled based on the rotational position and rotational speed of the rotor 16 by a control device (not shown) that controls energization to the coil 11b. ing. In addition to the resolver described above, the means for detecting the position of the rotor 16 may be a magnetic sensor such as a Hall element, a rotary encoder, or the like.

  Of course, the ball bearing 14 and the resolver stator 13b may be fixed directly to the casing 10 without the sensor holder 13 interposed therebetween. There is an advantage that the ball bearing 14 and the resolver stator 13b can be fixed in the casing 10 without performing any processing.

  And the motor M comprised in this way is attached to the upper end of the holder 5 in FIG. Specifically, the motor M is fixed to the upper end of the holder 5 by screwing a bolt 19 penetrating the flange 10 a of the casing 10 and the flange 12 b of the cap 12 into a nut portion 5 a provided on the outer periphery of the upper end of the holder 5. Is done.

 When the motor M and the holder 5 are integrated, the lower end of the shaft 17 is inserted into the inner periphery of the socket 1b of the ball screw nut 1, and the shaft 17 of the motor M and the ball screw nut 1 are connected to each other. The ball screw nut 1 is rotationally driven by M so that the screw shaft 2 can be linearly moved in the vertical direction in FIG. When the motor M is fixed to the holder 5 in this way, the motion conversion mechanism T of the motor M is connected, and the actuator A can be assembled.

 In addition, a tolerance ring 20 is interposed between the outer periphery of the shaft 17 and the inner periphery of the socket 1b. The tolerance ring 20 is provided around the axis acting on the shaft 17 and the ball screw nut 1. It functions as a torque limiter that regulates the upper limit of the relative rotational torque.

 Specifically, the tolerance ring 20 is a ring-shaped corrugated plate material. When the tolerance ring 20 is interposed between the shaft 17 and the socket 1b, the waves formed on the plate material are compressed in the radial direction. A frictional force is exerted between the tolerance ring 20 and the shaft 17 and the socket 1b so as to resist the relative rotation of the shaft 17 and the socket 1b according to the urging force, and the relative torque that causes the relative rotation is generated. Until the frictional force is exceeded, the shaft 17 and the ball screw nut 1 are not integrally rotated relative to each other, and when the relative torque exceeds the maximum frictional force, the shaft 17 and the ball screw nut 1 are relatively rotated. Thus, by functioning in this way, it functions as a torque limiter.

  As described above, in the suspension device S of the present embodiment, the relative vibration between the sprung member and the unsprung member in the vehicle is suppressed, but an external force that causes the suspension device S to rapidly expand and contract is input. In this case, the linear motion acceleration of the screw shaft 2 is large, the torque for rotating the ball screw nut 1 is very large, and the relative torque for relatively rotating the shaft 17 and the ball screw nut 1 is the tolerance ring 20. As a result, the ball screw nut 1 slips and idles with respect to the shaft 17. Then, only the ball screw nut 1 rotates without rotating the shaft 17, and the torque generated by the motor M based on the moment of inertia and electromagnetic force is suppressed from being transmitted to the ball screw nut 1.

  Therefore, under the above situation, that is, when the stroke speed of the suspension device S changes greatly, the transmission of the torque generated by the motor M to the ball screw nut 1 is suppressed, and the ball screw nut 1 Since the torque exceeding the allowable relative torque according to the biasing force of the tolerance ring 20 does not act, the influence of the moment of inertia of the motor M can be mitigated and the generated damping force of the suspension device S can be prevented from becoming excessive. The sudden vibration input to the unsprung member is suppressed from being transmitted to the sprung member.

  In the above description, the tolerance ring 20 is used as the torque limiter. However, instead of this, a friction body that generates a frictional force in the shaft 17 and the socket 1b may be interposed. As the friction body, for example, an annular rubber or an annular plate having a rough surface can be adopted.

  The relative torque set by the tolerance ring 20 or the friction body can be arbitrarily adjusted according to the vibration control target to which the suspension device S is applied. What is necessary is just to set to the value obtained experimentally and empirically so that the influence of the generated moment of inertia can be relieved.

  As described above, in the suspension device S of the present embodiment, the influence of the inertia moment that the moment of inertia of the motor M is superimposed on the torque caused by the electromagnetic force of the motor M and the generated damping force becomes excessive. Since the vehicle can be relaxed, the ride comfort in the vehicle can be improved.

  In other words, the ball screw nut 1 is not subjected to a torque exceeding the allowable relative torque, and there is no fear that the motion conversion mechanism T is damaged due to the excessive torque. In addition, the motor M The large angular acceleration acting on the rotor 16 is also suppressed, the scattering of the magnet 18 fixed around the rotor 16 can be prevented, and the load on the motor M can be reduced. Will improve.

  Furthermore, according to the suspension device S of the present embodiment, the tolerance ring 20 as a torque limiter is interposed in the fitting portion between the cylindrical shaft 17 of the motor M and the socket 1b of the ball screw nut 1. Since the influence on the overall length of the suspension device S is slight and the torque limiter is provided in a portion that does not affect the stroke length, it is easy to ensure the stroke length.

  In this embodiment, the shaft 17 and the ball screw nut 1 are connected via the tolerance ring 20. However, if it is not necessary to provide a torque limiter, the ball screw nut 1 is attached to the shaft 17 of the rotor 16. The ball screw nut 1 itself may be attached to the outer periphery of the ball screw nut 1 with the ball screw nut 1 itself as a shaft of the rotor 16 of the motor M. In this document, the ball screw nut 1 is attached to the motor. The concept of coupling to M is not limited to whether the ball screw nut 1 and the motor M are directly or indirectly, and the concept includes the ball screw nut 1 itself as the rotor 16. When the ball screw nut 1 is directly attached to the shaft 17 of the rotor 16, a spline or key may be used as a detent, and a configuration in which the ball screw nut 1 is fitted to the inner periphery of the shaft 17 is adopted. Also good.

 Returning, the actuator A configured as described above is connected to the mount 22 via a vibration isolating rubber 21 mounted on the mounting portion 5 d on the outer periphery of the holder 5. Specifically, the mount 22 includes a mount cylinder 23, an annular plate 24 connected to a sprung member (not shown) of the vehicle, and an anti-vibration rubber 25 that connects the mount cylinder 23 and the plate 24. The inner periphery of the lower end of the mount cylinder 23 in FIG. 1 is joined to the outer periphery of the holding ring 26 that holds the outer periphery of the anti-vibration rubber 21 attached to the outer periphery of the holder 5. The holding ring 26 includes a holding ring main body 26a having a U-shaped cross section for holding the vibration isolating rubber 21, and a cylindrical socket portion 26b hanging from the inner periphery of the lower end of the holding ring main body 26a in FIG. The spring receiver 43 is attached to the socket portion 26b.

 Thus, the actuator A and the mount 22 are connected, and the actuator A is connected to the sprung member of the vehicle via the mount 22.

 An outer cylinder 27 is joined to the outer periphery of the holding ring 26 that holds the vibration isolating rubber 21, and the lower end of the outer cylinder 27 in FIG. 1 is fitted to the inner periphery of the lower end of the outer cylinder 27. An annular end cap 29 that supports the lower end of the combined annular cushion 28 and has an L-shaped cross section is screwed.

  Furthermore, in the case of the suspension device S in the present embodiment, the screw shaft 2 is connected in series to the rod 31 of the fluid pressure damper D via the connecting shaft 30 as shown in FIG. The fluid pressure damper D is well known and not shown in detail, but a cylinder 32 and a piston (not shown) that is slidably inserted into the cylinder 32 and separates two pressure chambers (not shown) in the cylinder 32, The rod 31 is connected to the piston at one end and protrudes from the cylinder 32. The rod 31 is formed in the cylinder 32 and compensates for the rod volume that moves forward and backward to the cylinder 32. Sometimes exhibits a predetermined damping force.

  The fluid pressure damper D may be a so-called single cylinder type having an air chamber in the cylinder 32 or a so-called double cylinder type having an annular reservoir, but the fluid pressure damper D is made a double cylinder type. There is an advantage that the entire length of the suspension device S can be shortened by shortening the overall length of the fluid pressure damper D. Further, an annular cushion 40 is provided on the outer periphery of the upper end of the rod 31 so as to abut against the upper end of the cylinder 31 in FIG. .

  In the suspension device S according to the present embodiment, the connecting shaft 30 extends from the upper end of the rod 31 of the fluid pressure damper D, and the connecting shaft 30 is a base end connected to the upper end of the rod 31. A taper portion 30a is formed as an engaging portion that engages with the fluid pressure damper side end portion of the screw shaft 2 by expanding the diameter of the middle and lower ends, and a screw portion 30b is formed at the upper end in FIG. ing. In this embodiment, the rod 31 and the connecting shaft 30 are integrally formed. However, the rod 31 and the connecting shaft 30 may be configured as separate members and connected. In this example, the rod 31 is connected to the screw shaft 2 by the connecting shaft 30, but the cylinder 32 is connected to the screw shaft 2 by the connecting shaft 30 with the fluid pressure damper D being an inverted type. May be.

  An annular disk 33 fitted to the lower end of the screw shaft 2 is mounted on the outer periphery of the taper portion 30a of the connecting shaft 30. The outer periphery of the disk 33 is in sliding contact with the inner periphery of the outer cylinder 27. A bearing 34 that functions as a bearing in the expansion / contraction direction of S is mounted. The shape of the bearing 34 is not limited to that shown in the figure as long as it can slide on the inner periphery of the outer cylinder 27 to guide expansion and contraction of the suspension device S and suppress shaft shake.

  An annular bump cushion 41 is attached to the outer periphery of the lower end in FIG. 1 of the screw shaft 2. The bump cushion 41 is restricted from moving downward by the disk 33, and the holder 5 is moved when the actuator A is contracted most. The most contraction stroke length of the actuator A is regulated by abutting with the lower end.

  The cushion 40 regulates the most contraction stroke length of the fluid pressure damper D, and the bump cushion 41 regulates the most contraction stroke length of the actuator A. The cushion 40 and the bump cushion 41 allow the suspension device S to be The maximum contraction stroke length is regulated.

  Further, the connecting shaft 30 is inserted into the screw shaft 2, and the nut 35 is screwed into the tip of the anti-fluid pressure damper side, that is, the screw portion 30b at the tip opposite to the fluid pressure damper D side. Connected to the screw shaft 2. That is, in this case, the connecting shaft 30 is connected to the screw shaft 2 by sandwiching the screw shaft 2 together with the disk 33 by the taper portion 30a of the connecting shaft 30 and the nut 35, and the connecting shaft 30 is connected to the anti-fluid pressure damper side. It can be connected to the screw shaft 2.

  That is, when assembling the fluid pressure damper D and the actuator A, the upper side in FIG. 1 which is the anti-fluid pressure damper side is not connected between the fluid pressure damper D and the actuator A which are heavy objects. Since the fluid pressure damper D and the actuator A can be integrated only by the operation from the side, the operation of connecting the fluid pressure damper D and the actuator A becomes easy, and the burden on the operator is drastically reduced. .

  In order to engage the engaging portion of the connecting shaft 30, in this case, the tapered portion 30 a with the end of the screw shaft 2 on the fluid pressure damper side, it is brought into direct contact with the end of the screw shaft 2 with the fluid pressure damper. In addition to restricting the upward movement of the connecting shaft 30 with respect to the screw shaft 2 in FIG. 1, as described above, a member such as a disk 33 is provided between the end of the screw shaft 2 on the fluid pressure damper side and the engaging portion. 1 to restrict the upward movement of the connecting shaft 30 relative to the screw shaft 2 in FIG. Further, the shape of the engaging portion may not be the tapered portion 30a as long as it can regulate the upward movement of the connecting shaft 30 with respect to the screw shaft 2 in FIG. 1, but the tapered portion 30a is adopted. By doing so, there is an advantage that the disk 33 and the screw shaft 2 can be easily tightened and centered, and even if the disk 33 and the screw shaft 2 are loose, the taper portion 30a can be tightened upward in FIG. Thus, the shaft 34 is prevented from being displaced with respect to the screw shaft 2, and the expansion and contraction of the suspension device S can be maintained smoothly.

  Further, in the case of this embodiment, a hooked cylindrical spacer 36 for centering the screw shaft 2 at the upper end of the connecting shaft 30 is fitted into the upper end opening of the screw shaft 2. The inner periphery of the shaft is slidably contacted with the outer periphery of the connecting shaft 30 to prevent centering and rattling of the upper end of the connecting shaft 30 with respect to the screw shaft 2, thereby preventing interference between the connecting shaft 30 and the screw shaft 2 at the time of vibration input. . Further, since the backlash of the connecting shaft 30 can be prevented by the spacer 36, the loosening of the nut 35 at the time of vibration input is suppressed.

  As described above, the connecting shaft 30 is inserted into the screw shaft 2 and is connected to the screw shaft 2 from the anti-fluid pressure damper side of the screw shaft 2, so that the connecting shaft 30 is set to be long and extends in the vertical direction in FIG. It can act as a spring element in the longitudinal direction with respect to the moving screw shaft 2 and can suppress shaft breakage and loosening of the nut 35.

  Further, in this case, since the screw shaft 2 and the connecting shaft 30 are screwed and detachable, only the fluid pressure damper D or only the motion conversion mechanism T in the configuration of the suspension device S can be replaced. When necessary, it can be easily replaced, and it can be disassembled to inspect only the defective part. As described above, the screw shaft 2 and the connecting shaft 30 are detachably connected, thereby facilitating maintenance of the suspension device S and facilitating parts replacement. However, the screw shaft 2 and the connecting shaft 30 are welded. Basically, such as brazing, the screw shaft 2 and the connecting shaft 30 can be fixedly connected. In this case, there is no merit in terms of maintenance and parts replacement, but the point of facilitating the assembly of the fluid pressure damper D and the actuator A is the same as that in which the screw shaft 2 and the connecting shaft 30 are detachably connected. is there. In other words, the connection between the screw shaft 2 and the connecting shaft 30 includes not only the attachment / detachment but also the fixing without the intention of attachment / detachment, and a method other than the screw fastening is used. And may be detachable.

  Note that, in the above, in order to facilitate the connecting operation of integrating the fluid pressure damper D and the actuator A in the suspension device S, the screw shaft 2 is cylindrical and the connecting shaft 30 is the anti-fluid pressure of the screw shaft 2. Although it can be connected from the damper side, the screw shaft 2 is directly connected to the rod 31 or the cylinder 32 of the fluid pressure damper D in the middle of the fluid pressure damper D and the actuator A without making the screw shaft 2 cylindrical. You can also

  Subsequently, a cover cylinder 37 that covers the cylinder 32 and forms an annular gap with the cylinder 32 is provided on the outer periphery of the side of the cylinder 32 of the fluid pressure damper D. The upper end of the cover cylinder 37 is bent. Thus, a flange 37a is formed.

  Then, the flange portion 37a of the cover cylinder 37 comes into contact with a cushion 28 fitted to the inner periphery of the lower end in FIG. Regulates the entire extension of the suspension device S.

 Since the fluid pressure damper D and the actuator A expand and contract independently, if there is no restriction, the maximum extension stroke length of the suspension device S as a whole is the sum of the maximum extension stroke lengths of the fluid pressure damper D and the actuator A. For this reason, the entire extension stroke length of the suspension device S is regulated by the flange portion 37a and the cushion 28.

 An annular spring receiver 42 is placed and accommodated on the bottom of the cover cylinder 37 on the inner periphery of the lower end of the cover cylinder 37. Between the spring receiver 42 and the lower end of the bearing 34 described above, A spring 38 arranged in parallel to the fluid pressure damper D is interposed, and further, arranged in parallel to the actuator A between the spring receiver 43 attached to the socket portion 26b of the holding ring 26 and the upper end of the bearing 34. A spring 39 is interposed. Thus, the springs 38 and 39 function as suspension springs that support the weight of the sprung member of the vehicle, and the springs 38 are arranged in parallel to the fluid pressure damper D to attach the fluid pressure damper D in the extending direction. The spring 39 is arranged in parallel with the actuator A to urge the fluid pressure damper D in the contracting direction, and also exhibits the function of positioning the rod 31 of the fluid pressure damper D in the neutral position with respect to the cylinder 32. is doing.

  Thus, the springs 38 and 39 as suspension springs are supported by the holding ring 26 whose upper end is coupled to the mount 22, while the actuator A is elastically supported by the mount 22 via the vibration isolating rubber 21. Therefore, the vibrations of the springs 38 and 39 as the suspension spring are not directly transmitted to the actuator A, and the vibration is insulated from the suspension spring.

  Further, these springs 38 and 39 function to suppress the vibration of the unsprung member of the vehicle from being transmitted to the motor M side, that is, the sprung member, and at the same time, are connected to the cylinder 32 of the fluid pressure damper D. The effect | action which returns 31 to a neutral position is exhibited. As described above, when the vibration of the suspension device S converges, the springs 38 and 39 return the rod 31 to the neutral position with respect to the cylinder 32, so that the piston remains in the vicinity of the upper end and the lower end with respect to the cylinder 32. There is no risk that the piston will interfere with the upper or lower end of the cylinder 32 even when the vibration is input thereafter, thereby deteriorating the ride comfort in the vehicle or reducing the reliability of the suspension device S. Absent.

  The neutral position is a position where the rod 31 is positioned with respect to the cylinder 32 in a state in which the sprung member in the vehicle is supported by the springs 38 and 39, and the piston connected to the end of the rod 31 is It does not indicate only the rod position that is in the state of being located at the center of the cylinder 32.

 In this case, since the functions of positioning the fluid pressure damper D to the neutral position of the rod 31 can be integrated into the springs 38 and 39 which are suspension springs, only the positioning function to the neutral position or the suspension spring function However, it is possible to reduce the number of parts in the suspension device S and reduce the cost. However, the springs 38 and 39 are eliminated, and a separate suspension spring is provided to provide a fluid pressure damper. When the spring is accommodated in each pressure chamber in D to position and return the rod 31 to the neutral position with respect to the cylinder 32, a suspension spring may be provided separately. The upper end of the suspension spring is not only supported by the mount 22 but also by the sprung member, so that the suspension spring is indirectly interposed between the mount 22 and the unsprung member. It may be.

  As described above, when the rod 31 is positioned and returned to the neutral position with respect to the cylinder 32 by means other than the springs 38 and 39, for example, the upper end of the cover cylinder 37 is bent inward to A pair of cylinder-side spring bearings that are axially immovable on the cylinder 32 are provided on the outer periphery of the cylinder 32 at an annular bottom portion and a bent portion toward the inside of the upper end, and a rod-side spring coupled to the rod 31 between the spring bearings. A support may be arranged, and each spring for energizing the fluid pressure damper D in the extension and expansion / contraction directions may be interposed at two locations between the cylinder side spring support and the rod side spring support.

  In the suspension device S, the fluid pressure damper D is connected in series to the screw shaft 2 that is linearly moved by the motor M, so that the vehicle travels on a rough road, When a high-frequency vibration such as a vibration having a relatively large acceleration is input to the unsprung member when riding on the protrusion, for example, the vibration energy is absorbed and the vibration transmission suppressing effect by the springs 38 and 39 described above is absorbed. Together with this, it acts to make it difficult to transmit vibration to the screw shaft 2 side.

  Here, in the suspension device S, vibration that is linear motion input from the unsprung member is converted into rotational motion. However, the suspension device S includes many rotating members and has a large inertial mass and a high frequency. There is a characteristic that vibration of the unsprung member is easily transmitted to the sprung member due to the fact that the moment of inertia increases with respect to vibration and the influence of the friction between the bearing 34 and the outer cylinder 27. As described above, the fluid pressure damper D absorbs the vibration, and the springs 38 and 39 exhibit the vibration transmission suppressing effect, so that the transmission of vibration to the screw shaft 2 is suppressed. Transmission can be effectively suppressed.

  In this suspension device, the bearing 34 is in sliding contact with the inner periphery of the outer cylinder 27 and functions as a bearing for the entire expansion and contraction of the suspension device S. This bearing 34 absorbs high-frequency vibrations. For the expansion / contraction of only the fluid pressure damper D, the bearing 34 gives resistance to the expansion / contraction of the fluid pressure damper D because it does not move up and down in FIG. No.

  In other words, the bearing 34 is in sliding contact with a portion that does not affect the expansion and contraction of the fluid pressure damper D, and the smooth expansion and contraction of the fluid pressure damper D is compensated. Positively expands and contracts the fluid pressure damper D to absorb vibrations, thereby improving the vibration insulation of the sprung member and improving the riding comfort in the vehicle.

  Furthermore, since the bearing 34 does not hinder the expansion and contraction of the fluid pressure damper D with respect to the input of high-frequency vibration, it is possible to prevent the shock force from acting directly on the actuator A to protect the motor M and the motion conversion mechanism T. Thus, the reliability of the actuator A, which is a main component of the suspension apparatus S, is improved, and the problems of the conventional suspension apparatus can be solved and the reliability of the suspension apparatus S can be improved.

  In this case, the bearing 34 is interposed between the spring 38 arranged in parallel with the fluid pressure damper D and the spring 39 arranged in parallel with the actuator A, and functions as a spring receiver for each spring 38, 39. Therefore, there is no need to provide a member that functions only as a separate spring support, and in combination with the reduction of the number of parts by the springs 38 and 39 that function as a positioning to the neutral position of the suspension spring and the fluid pressure damper D, It is possible to significantly reduce the number of parts in the suspension device S and to reduce the cost. Furthermore, since the springs 38 and 39 are disposed in the outer cylinder 27, the suspension spring can be protected.

  When the suspension spring is provided on the outer peripheral side of the outer cylinder 27, the bearing 34 loses its function as a spring receiver for the springs 38 and 39, but in this case as well, a fluid pressure damper that absorbs high-frequency vibrations. For the expansion and contraction of only D, the bearing 34 does not move up and down in FIG. 1, which is the axial direction with respect to the outer cylinder 27, so the effect of improving the riding comfort in the vehicle is not lost. Furthermore, in this embodiment, since it is the rod 31 of the fluid pressure damper D that is connected to the screw shaft 2 as the linear motion member, the bearing 34 is attached to the rod 31, but the linear motion of the actuator A When the cylinder 32 is connected to the member, the bearing 34 may be attached to the cylinder 32. Even if it does in this way, since the bearing 34 does not prevent expansion-contraction of the fluid pressure damper D, the said effect is not lost.

  Further, in the suspension device S according to the present embodiment, the actuator A is elastically supported by the mount 22 connected to the sprung member via the anti-vibration rubber 21, and the vibration of the actuator A having a large inertia weight is directly applied to the sprung member. And the springs 38 and 39 as suspension springs are vibration-insulated by the presence of the vibration-proof rubber 21, so that they vibrate between the sprung member and the unsprung member. The vibration of the sprung member due to the inertia of the actuator A is also suppressed.

  Further, by adopting the above-described configuration that elastically supports the actuator A and insulates it from the springs 38 and 39 that are suspension springs, the high-pressure vibration cannot be absorbed by the fluid pressure damper D. Even if the actuator A that does not easily expand and contract with respect to the high-frequency vibration input becomes a so-called rod-like situation, the vibration is absorbed by the anti-vibration rubber 21 and the vibration is transmitted to the sprung member. Can be insulated.

  That is, by adopting the above-described configuration that elastically supports the actuator A and is insulated from the springs 38 and 39 that are suspension springs, the ride comfort in the vehicle can be improved.

  Further, since high-frequency vibration is prevented from directly acting on the actuator A arranged on the sprung member side by the fluid pressure damper D arranged on the unsprung member side, the motor M has particularly high acceleration. Transmission of high-frequency vibration is suppressed, and in addition to the effect of the bearing 34, the actuator A is arranged on the sprung member side, so that the reliability of the actuator A, which is the main component of the suspension device S, is improved. It is possible to improve the reliability of the suspension device S by eliminating the problem of the suspension device.

  In the suspension apparatus S, the actuator A and the fluid pressure damper D are accommodated in the outer cylinder 27, the cover cylinder 37, and the mount 22, and the main drive portion of the suspension apparatus S is isolated from the outside of the suspension apparatus S. As a result, the intrusion of rainwater into the suspension device S and the contact of stepping stones with the main drive portion are reliably prevented. Therefore, this improves the practicality of the suspension device S.

  Here, in order to actually assemble the suspension device S configured as described above, the connecting shaft 30 connected to the rod 31 of the fluid pressure damper D is used for the assembly of only the motion conversion mechanism T held by the holder 5. Is inserted into the disk 33 with the bearing 34 and the screw shaft 2 and the nut 35 is screwed into the screw portion 30b at the upper end of the connecting shaft 30 from the upper end side in FIG. D can be integrated, and then the assembly of the suspension device S is completed by attaching the motor M to the upper end of the holder 5.

  In addition, since the motor M includes the cylindrical shaft 17 and the screw shaft 2 is inserted into the shaft 17, the motion conversion mechanism T and the fluid pressure damper D are integrated, and then the anti-fluid The shaft 17 of the motor M can be connected to the ball screw nut 1 in the motion conversion mechanism T from the pressure damper side, and the assembly of the suspension device S is facilitated.

  In this case, the motion conversion mechanism T is configured to include a ball screw nut 1 that exhibits rotational motion and a screw shaft 2 that is a linear motion member that exhibits linear motion. The ball screw nut 1 may be connected to the fluid pressure damper D using the ball screw nut 1 as a linear motion member. In this embodiment, the motion conversion mechanism T is a feed screw mechanism composed of the screw shaft 2 and the ball screw nut 1. However, the motion conversion mechanism T is composed of a mechanism such as a rack and pinion or a worm gear. May be.

  In the above description, since the smooth vertical movement of the screw shaft 2 can be realized, the anti-rotation mechanism is the ball spline nut 3 that engages with the spline groove provided on the outer periphery of the screw shaft 2. Even if the outer periphery of the screw shaft 2 is formed with a groove along its axis and the screw shaft 2 is prevented from rotating with a member such as a key that does not obstruct the vertical movement of the screw shaft 2, The anti-rotation mechanism can be held by the holder 5, and this may be used.

  This is the end of the description of the embodiment of the present invention, but the scope of the present invention is of course not limited to the details shown or described.

It is a longitudinal cross-sectional view of the suspension apparatus in one embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ball screw nut 1a which is rotating member Ring groove 1b Socket 2 Screw shaft 3 which is a linear motion member Ball spline nut 3a, 5e Key groove 5 Holder 5a Holder nut part 5b Holder flange 5c Holder step part 5d Holder attachment part 6 Key 7 Snap ring 8 Nut 9, 14, 15 Ball bearing 9a Ball 9b in ball bearing Outer ring 10 in ball bearing Casing 10a Flange in casing 11 Stator 11a Core 11b Coil 12 Cap 12a Cylindrical portion 12b Cap flange 12c In cap Fitting portion 13 Sensor holder 13a Resolver stator 13b Resolver core 16 Rotor 17 Shaft 18 Magnet 19 Bolt 20 Tolerance ring 21 Anti-vibration go 22 mount 23 mount cylinder 24 mount plate 25 mount vibration-proof rubber 26 mount ring 26a holding ring body 26b socket 27 outer cylinder 28, 40 cushion 29 end cap 30 connecting shaft 30a engaging portion on connecting shaft Tapered portion 30b Threaded portion 31 in connecting shaft Rod 32 in fluid pressure damper Cylinder 33 in fluid pressure damper 33 Disc 34 Bearing 35 Nut 36 Spacer 37 Cover cylinder 37a Hook 38, 39 Spring 41 Bump cushion 42, 43 Spring receiver A Actuator D Fluid pressure damper M Motor S Suspension device T Motion conversion mechanism

Claims (2)

An actuator including a motion conversion mechanism that converts linear motion into rotational motion, a motor coupled to a rotating member that exhibits rotational motion in the motion conversion mechanism, and a linear motion member that exhibits linear motion in the motion conversion mechanism In a suspension device including a fluid pressure damper, an outer cylinder coupled to an actuator and a bearing attached to a rod or cylinder coupled to a linear motion member of the fluid pressure damper and slidably contacting the inner periphery of the outer cylinder are provided. A suspension device characterized by that. 2. A suspension spring is constituted by a spring arranged in parallel to the fluid pressure damper and a spring arranged in parallel to the actuator, and a bearing is interposed between each of the springs to serve as a spring receiver. The suspension device described in 1.

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