JP4526895B2 - Suspension device - Google Patents

Description

  The present invention relates to a suspension device that uses an electromagnetic force generated in a motor as a control force that suppresses relative movement between the vehicle body side member and the axle side member.

This type of suspension device includes a coil spring that elastically supports the vehicle body, a screw shaft that is rotatably engaged with a ball screw nut that is connected to the axle side, and one end of the screw shaft that is connected to the vehicle body side. Some motors are configured to actively control the relative movement between the vehicle body and the axle with the rotational torque generated by the motor.
Japanese Patent Laid-Open No. 08-197931 (paragraph number 0023, FIG. 1)

  In general, by loading luggage on the vehicle or increasing or decreasing the number of passengers, the driver's line of sight changes when the vehicle height changes, and at night, the position of the center of gravity of the vehicle changes. Since the direction changes and the driving environment changes for the driver, the vehicle height is preferably constant regardless of the weight of the load loaded on the vehicle and the number of passengers. Further, when considering the attitude control of the vehicle, appropriate control is possible by keeping the vehicle height constant.

  In particular, in a large vehicle, it is easy to board the vehicle while the vehicle is stopped, and it is preferable to maintain a certain vehicle height for the above reason during traveling.

  Here, in order to adjust the vehicle height with the conventional suspension device, it is necessary to constantly maintain a state in which the rotational torque is generated in the motor, that is, to load the vehicle body weight borne by the coil spring on the motor.

  Then, since a current always flows in the coil of the motor, the coil itself generates heat, and when the motor temperature rises greatly due to the heat of the coil, the chemical change of the insulating coating of the conductive wire forming the coil As a result, there is a risk that the insulation will deteriorate, resulting in leakage of electric current and the like, and the motor itself may be damaged, and the magnet may be demagnetized due to the temperature rise of the motor.

  In particular, in this type of suspension device, the motor is an indispensable part that generates a damping force. Therefore, the motor is damaged, that is, the function of the suspension device is impaired.

  Accordingly, the present invention has been made in consideration of the above-mentioned problems, and an object of the present invention is to provide a suspension device that can adjust the vehicle height and suppress the temperature rise of the motor. It is.

In order to achieve the above object, one means of the present invention includes a shock absorber and an air spring, and the shock absorber is a ball screw nut, and a screw shaft that is rotatably screwed into the ball screw nut; A motor connected to a screw shaft, the air spring is provided outside the motor, the shaft to which the motor is connected to the screw shaft, a magnet attached to the outer periphery of the shaft via a yoke, and a magnet And a coil fitted to the core, the linear motion of the ball screw nut is converted into the rotational motion of the screw shaft, and this rotational motion is transmitted to the shaft of the motor. Attenuation that suppresses the linear motion of the ball screw nut by generating an electromagnetic force in the motor and suppressing the rotational motion of the screw shaft with a torque that resists the rotation of the shaft due to the electromagnetic force. In suspension system is utilized as, the yoke or forming a hole for supplying and discharging the gas within the air spring to the core, and changing a vehicle height adjustment of the constants of air spring by supplying and discharging gas into the air spring The motor is cooled at the same time.
Similarly, the other means includes a mount, a shock absorber, and an air spring. The mount includes a mount inner cylinder and a mount outer cylinder disposed on the outer periphery of the mount inner cylinder. The shock absorber is on the axle side. An outer cylinder connected to the member, an inner cylinder slidably inserted into the outer cylinder and connected to the vehicle body side member, a ball screw nut provided on the bottom side of the outer cylinder, and a ball screw nut A screw shaft that is rotatably engaged; and a motor that is coupled to the upper end of the inner cylinder via the mount inner cylinder and coupled to the screw shaft; and the air spring includes the outer cylinder and the inner cylinder. It provided the outside, and a case in which the motor is housed in the cylinder above mount, a shaft connected to the screw shaft, and a magnet mounted via a yoke on the outer circumference of the shaft, opposite the magnet An attached core and a coil fitted to the core; The linear motion of the ball screw nut is converted into the rotational motion of the screw shaft, and this rotational motion is transmitted to the shaft of the motor to generate an electromagnetic force in the motor. In the suspension device that uses a torque that resists the rotation of the shaft as a damping force that suppresses the linear motion of the ball screw nut by suppressing the rotational motion of the screw shaft, the mount inner cylinder, the case, Holes for supplying and discharging gas into the air spring are formed in the yoke and the core, respectively, and changing the air spring constant, adjusting the vehicle height, and cooling the motor simultaneously by supplying and discharging gas into the air spring. It is characterized by.
In the case of each means described above, an open / close valve may be provided in the middle of the hole.

  According to the present invention, the coil that is supplied with current throughout the vehicle height adjustment and vehicle height generation generates heat, but the gas supply and discharge into the air spring is performed from vehicle height adjustment to vehicle height maintenance. However, since it is performed through the motor, the coil is quickly cooled by the passage of gas in the motor.

  Therefore, the temperature rise of the coil is suppressed, the motor does not accumulate heat, the temperature rise of the motor can be suppressed, and the insulation is deteriorated due to the chemical change of the insulating film of the conductive wire forming the coil, etc. There is no risk of electric leakage and damage to the motor itself.

  Furthermore, since damage to the motor can be avoided, it is possible to prevent a situation in which the suspension function is impaired.

  Moreover, while being able to suppress the temperature rise of a motor, gas passes through the clearance gap between a magnet and a core, an air curtain effect is exhibited, and it is prevented that the heat of a coil is transmitted to a magnet, There is no risk of performance degradation such as a decrease in torque generated by the motor due to thermal demagnetization of the magnet.

  That is, it becomes possible to adjust the vehicle height and to suppress the temperature rise of the motor.

  The present invention will be described below based on the embodiments shown in the drawings. FIG. 1 is a diagram conceptually showing a suspension device according to an embodiment. FIG. 2 is a longitudinal sectional view of a motor in the suspension device. FIG. 3 is a longitudinal sectional view of a motor having a through hole in the yoke. FIG. 4 is a longitudinal sectional view of a motor provided with a through hole in the core of the armature. FIG. 5 is a longitudinal sectional view of a motor having a through hole in the case.

  As shown in FIG. 1, a suspension apparatus according to an embodiment includes a motion conversion mechanism H that converts relative motion between a vehicle body side member and an axle side member in a vehicle (not shown) into rotational motion, and a motor that transmits the rotational motion. The shock absorber S is composed of M, and the air spring C is interposed between the vehicle body side member and the axle side member.

  As shown in FIG. 2, the suspension device is connected to a compressor, an auxiliary tank, or the like via a tube 70 communicating with the motor M so that gas can be supplied to and discharged from the air spring C via the motor M. The vehicle height can be adjusted by changing the spring constant of the air spring C or by actively supplying gas into the air spring C.

  The shock absorber S is inserted into the inner cylinder 5 that rises from the bottom of the outer cylinder 2 and the inner cylinder 5 that is slidably inserted into the outer cylinder 2. A ball screw nut 4 provided at the upper end in FIG. 1 of the connecting cylinder 6, a screw shaft 3 screwed into the ball screw nut 4 in a freely rotatable manner, and an upper end in FIG. And a motor M connected to the screw shaft 3, and the linear motion of the ball screw nut 4 when the shock absorber S expands and contracts is converted into the rotational motion of the screw shaft 3, and the rotational motion is converted into the motor M. Of the ball screw nut 4 by suppressing the rotational movement of the screw shaft 3 with the torque that resists the rotation of the shaft 1 due to the electromagnetic force. The axial direction of the outer cylinder 2 and the inner cylinder 5 is used as a damping force that suppresses linear motion. In which it is possible to suppress the relative movement.

  In the case of the present embodiment, the shock absorber S is configured such that the outer cylinder 2 is connected to an axle side member of the vehicle via an eye E provided at the lower end of the outer cylinder 2 in FIG. Is connected to the vehicle body side member via the mount 20, and as a result, relative movement between the axle side member and the vehicle body side member can be suppressed.

 Hereinafter, the detailed structure of each part will be described. The motor M is mounted and connected in a mount inner cylinder 21 of a mount 20 connected to the upper end in FIG. 1 of the inner cylinder 5, and the shaft 1 of the motor M is in ball bearings 8 and 9 in the inner cylinder 5. Is connected to a screw shaft 3 that is rotatably inserted through the shaft. The shaft 1 of the motor M and the screw shaft 3 may be formed integrally.

 Further, as described above, the mount 20 for attaching the suspension device to the vehicle is provided at the upper end of the inner cylinder 5 in FIG. 1. The mount 20 includes a mount inner cylinder 21 and an outer mount. In addition to the hole into which the shaft 1 of the motor M is inserted at the bottom of the mount inner cylinder 21, the cylinder 22 and the vibration isolating rubber 23 connecting the mount inner cylinder 21 and the mount outer cylinder 22 are separately provided. The hole 21 a is provided at a position where it does not interfere with the inner cylinder 5.

 Specifically, the mount outer cylinder 22 is connected to the vehicle body side, and the suspension device is connected to the vehicle body side.

 On the other hand, as shown in FIG. 2, the motor M includes a case 30, the shaft 1, a magnet 32 attached to the outer periphery of the shaft 1 via a cylindrical yoke 31, and the inner periphery of the case 30. A core 33 that is an armature core attached so as to face the magnet 32, and a coil 34 fitted to the core 33, is configured as a so-called brushless motor.

 The magnet 32 is formed in an annular shape and has a divided magnetic pole pattern in which the N pole and the S pole appear alternately along the circumference, but the plurality of magnets are bonded to form an annular shape. It may be formed.

 The motor M is connected to an external power source and a control device (not shown) so that the rotational torque of the shaft 1 can be controlled. The motor M is adjusted so as to obtain a desired damping force, and the motor M is positively activated. The shock absorber S is driven to function not only as a shock absorber but also as an actuator.

 Incidentally, although not shown, the motor M is equipped with a Hall element, a magnetic sensor, an optical sensor, etc. as a rotor position detecting means, and according to the state of rotational movement (rotation angle, angular velocity, etc.) of the rotor. Thus, the control force for suppressing the relative movement between the vehicle body side member and the axle side member generated by the shock absorber S can be controlled.

 In the present embodiment, the motor M is a brushless motor, but various motors such as a DC motor, an AC motor, an induction motor, etc. can be used as long as they can be used as an electromagnetic force generation source.

 In the case 30, holes 30a and 30b that allow gas to pass are formed in the upper end and the lower end in FIG. 1, and the hole 30b provided on the upper end side is connected to the tube 70 described above, The hole 30 a provided on the other lower end side is opposed to the hole 21 a provided in the mount inner cylinder 21.

 Further, a seal member 35, in this case, an O-ring, is interposed between the lower end surface in FIG. 1 of the case 30 and the bottom inner surface of the mount inner cylinder 21. There is no gas leakage from between.

 Incidentally, in the present embodiment, the mount inner cylinder 21 of the mount 20 may be utilized as a case of the motor M. In this case, the core 33 and the coil 34 are attached to the mount inner cylinder 21 and the mount inner cylinder What is necessary is just to provide the lid | cover which obstruct | occludes the upper-end opening part of FIG.

 Subsequently, the screw shaft 3 connected to the shaft 1 is provided with a screw groove on the outer periphery thereof, and a ball that is non-rotatably provided at the upper end portion in FIG. 1 of the connecting tube 6 rising from the bottom of the outer tube 2 described above. The screw nut 4 is rotatably screwed.

 The connecting cylinder 6 is not necessarily formed in a cylindrical shape, and may be any one that can connect the ball screw nut 4 to the outer cylinder 2 in a state where the rotation of the ball screw nut 4 is restricted.

  That is, in the case of this embodiment, the motion conversion mechanism H is constituted by the screw shaft 3 and the ball screw nut 4, and when the ball screw nut 4 performs a linear motion in the vertical direction in FIG. Since the rotation of the ball screw nut 4 is restricted by the outer cylinder 2 fixed to the axle side, the screw shaft 3 is forcibly driven to rotate, and conversely, the motor M is driven to rotate the screw shaft 3. Then, since the rotation of the ball screw nut 4 is restricted, it is possible to move the ball screw nut 4 in the vertical direction.

 Incidentally, bearings 10 and 11 are provided between the outer cylinder 2 and the inner cylinder 5 to prevent the inner cylinder 5 from being shaken with respect to the outer cylinder 2, and as a result, the axis of the screw shaft 3 with respect to the ball screw nut 4. As a result, it is possible to prevent the load from being concentrated on a part of the balls (not shown) of the ball screw nut 4 and to prevent the ball or the screw groove of the screw shaft 3 from being damaged. Is possible.

 Further, since the damage to the ball or the screw groove of the screw shaft 3 can be prevented, the smoothness of each operation of the rotation of the screw shaft 3 with respect to the ball screw nut 4 and the movement of the shock absorber S in the expansion / contraction direction can be maintained. Since the smoothness of each of the above operations can be maintained, the function as the shock absorber S is not impaired, and the failure of the shock absorber S can be prevented.

  In the present embodiment, the motion conversion mechanism H is constituted by a ball screw nut and a screw shaft. However, this may be constituted by another configuration, for example, a rack and pinion, or a ball screw. The nut may be replaced with a simple nut.

In turn, the air spring C includes a mount outer cylinder 22 of the mount 20, a substantially hollow conical pneumatic piston 40 that is attached to a side portion of the outer cylinder 2 and covers the outer cylinder 2. The air spring C is provided so as to cover the shock absorber S. The air spring C and the shock absorber S are provided with a diaphragm D fixed to the tip of the pneumatic piston 40 and the mount outer cylinder 22. And are integrated.

  The inside of the air spring C communicates with the motor M through the hole 21a of the mount inner cylinder 21 described above, and gas is supplied from a compressor or the like connected to the hole 30b of the motor M through the tube 70 into the air spring C. It can be discharged.

  Now, the suspension device of the present invention is configured as described above, and the operation thereof will be described below.

  First, the function of the shock absorber S in the suspension device will be described. When the shock absorber S expands and contracts, that is, when the inner cylinder 5 moves up and down in FIG. The vertical movement of the ball screw nut 4 is converted into the rotational movement of the screw shaft 3 by the ball screw mechanism of the ball screw nut 4 and the screw shaft 3, and the shaft 1 of the motor M connected to the screw shaft 3 is also converted. Rotate.

  When the shaft 1 of the motor M exhibits a rotational motion, the coil 34 in the motor M crosses the magnetic field of the magnet 32, and an induced electromotive force is generated. The electromagnetic force caused by the induced electromotive force is generated on the shaft 1 of the motor M. The above torque acts, and the torque suppresses the rotational movement of the shaft 1.

  The effect of suppressing the rotational movement of the shaft 1 is to suppress the rotational movement of the screw shaft 3, and the rotational movement of the screw shaft 3 is suppressed, so that the linear movement of the ball screw nut 4 is suppressed, The shock absorber S generates a control force that acts as a damping force in this case by the electromagnetic force, and absorbs and relaxes vibration energy.

  At this time, when the current is actively supplied to the coil 34, the expansion and contraction of the shock absorber S can be freely controlled by adjusting the torque acting on the shaft 1, that is, the range in which the control force of the shock absorber S can be generated. Therefore, the damping characteristic of the shock absorber S can be made variable, or the shock absorber S can function as an actuator.

  On the other hand, the air spring C normally keeps the gas amount in the air spring C constant and elastically supports the vehicle body, thereby mitigating the transmission of impact from the road surface to the vehicle body.

  Therefore, this suspension device can function not only as a general suspension device but also as a semi-active or active suspension.

  Next, the vehicle height adjustment will be described. In this suspension device, a current is supplied to the coil 34 of the motor M, and the shock absorber S is extended or contracted until the vehicle height reaches the target height. Complete the process.

  In order to maintain the vehicle height at the target height simultaneously with the current supply, when the vehicle height is increased, gas is supplied into the air spring C, and conversely, when the vehicle height is decreased, the air spring The gas is discharged from C, that is, the gas is supplied to and discharged from the air spring C while supplying current to the coil 34.

  Further, the current supply amount to the coil 34 is gradually reduced by the progress of gas supply / discharge to the air spring C, and the current supply to the coil 34 is finally achieved when the target vehicle height is achieved only by the air spring C. The vehicle height is maintained at the target height only by the air spring C.

  In this suspension device, it is possible to adjust the vehicle height only by supplying and discharging gas to and from the air spring C, but adjusting the vehicle height only by supplying and discharging gas to and from the air spring C is very slow. On the other hand, by using the motor M, that is, by using the electromagnetic force of the motor M, the vehicle height adjustment speed can be dramatically increased with high responsiveness.

  As described above, the vehicle height adjustment and the maintenance of the target vehicle height are performed, and the coil 34 that is supplied with current from the vehicle height adjustment until the vehicle height is maintained by the air spring C generates heat. Since the supply and discharge of the gas into the air spring C is performed through the motor M from the height adjustment to the vehicle height maintenance, the coil 34 is quickly cooled by the passage of the gas in the motor M. It becomes.

  Therefore, the temperature rise of the coil 34 is suppressed, the heat is not accumulated in the motor M, the temperature rise of the motor M can be suppressed, and the insulation is deteriorated due to the chemical change of the insulating film of the conductive wire forming the coil 34. As a result, there is no risk of electric leakage and the motor itself being damaged.

  Furthermore, since damage to the motor M can be avoided, a situation in which the suspension function is impaired can be prevented.

  In addition, the temperature rise of the motor M can be suppressed, and the gas passes through the gap between the magnet 32 and the core 33 to exhibit the air curtain effect, so that the heat of the coil 34 is transmitted to the magnet 32. Thus, there is no risk of performance deterioration such as a decrease in torque generated by the motor M due to thermal demagnetization of the magnet 32.

  That is, it becomes possible to adjust the vehicle height and to suppress the temperature rise of the motor.

Further, as shown in FIG. 3, if the yoke 31 is provided with holes made of a plurality of through holes 31 a at equal intervals on a concentric circle, the gas is not limited to the gap between the magnet 32 and the core 33. Since the gas can pass through the through hole 31a, it is possible to prevent the pressure loss when the gas passes through the motor M from being excessive, and to quickly supply and discharge the gas into the air spring C. Thus, it is possible to shorten the time required from the initial vehicle height adjustment to the vehicle height maintenance, and further, there is an advantage that it is not necessary to apply an excessive load to the pressure source that supplies gas into the air spring C.

Incidentally, a hole made of the through hole, in addition to the yoke 31 described above, as shown in FIG. 4, may be provided through holes 51 in the core 50 in the armature, as shown in FIG. 5, holes in casing 52 53 may be provided, and the same effect can be obtained.

  Here, when providing a through hole in the case or the core, as shown in FIGS. 4 and 5, the through hole may be formed by providing a groove in one of the case and the core.

  In the above description, the motor M and the air spring C communicate with each other through the hole 30a and the hole 21a. However, as long as the temperature rise in the motor M can be suppressed, the motor M and the air spring C may be communicated in any way.

 In addition, an air passage for communicating the air spring C and the motor M in the suspension device, specifically, for example, an opening / closing valve (not shown) for opening and closing the hole 30a of the case 30 and the hole 21a of the mount inner cylinder 21 is provided. A hole (not shown) that communicates the inside and outside of the case 30 may be provided, and an opening / closing valve (not shown) may be provided in the hole.

 In this case, at the time of vehicle height adjustment, the on-off valve provided in the air passage communicating the air spring C and the motor M is opened, while the on-off valve provided in the hole communicating the inside and outside of the case 30 is closed, and the air spring C is brought into the air spring C. Gas can be supplied and discharged.

  On the other hand, when there is no need to supply and discharge gas into the air spring C, for example, when the vehicle is running, the on-off valve provided in the air path that connects the air spring C and the motor M is closed and the inside and outside of the case 30 are communicated. If the on-off valve provided in the hole is opened, the inside of the motor M is maintained in communication with the outside, and even if the coil 34 generates heat due to a current flowing while the vehicle is running, the inside of the motor M is open. Further, it is prevented that heat is accumulated in the motor M and thermal demagnetization occurs in the magnet 32, and the heat of the coil 34 is transmitted to the gas in the air spring C to cause a change in the pressure in the air spring C. Thus, the adverse effect that the vehicle height cannot be maintained as set is prevented.

  When the opening / closing valve provided in the hole communicating with the inside and outside of the case 30 is opened to open the motor M, if the gas is supplied into the motor M via the tube 70, the motor M is continuously supplied. Since gas passes through the inside, the motor M can be forcibly cooled when the vehicle travels.

  Therefore, in this case, even when the vehicle is traveling, the temperature rise of the coil 34 is suppressed, the motor M does not accumulate heat, and the temperature rise of the motor M can be suppressed. There is no fear of the motor itself being damaged or the performance degradation of the motor M due to thermal demagnetization of the magnet 32.

  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 figure which shows notionally the suspension apparatus in one embodiment. It is a longitudinal cross-sectional view of the motor in a suspension apparatus. It is a longitudinal cross-sectional view of the motor provided with the through-hole in the yoke. It is a longitudinal cross-sectional view of the motor which provided the through-hole in the core in an armature. It is a longitudinal cross-sectional view of the motor provided with the through-hole in the case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Shaft 2 Outer cylinder 3 Screw shaft 4 Ball screw nut 5 Inner cylinder 6 Connecting cylinder 8, 9 Ball bearing 10, 11 Bearing 20 Mount 21 Mount inner cylinder 21a, 30a, 30b Hole 22 Mount outer cylinder 23 Anti-vibration rubber 30, 52 Case 31 Yoke 31a, 51, 53 Through-hole 32 Magnet 33, 50 Core 34 Coil 35 Seal member 40 Pneumatic piston 70 Tube C Air spring D Diaphragm E Eye H Motion conversion mechanism M Motor S Buffer

Claims (3)

The shock absorber (S) has a shock absorber (S) and an air spring (C). The shock absorber (S) includes a ball screw nut (4) and a screw shaft (3) that is rotatably engaged with the ball screw nut (4). And a motor (M) connected to the screw shaft (3), the air spring (C) is provided outside the motor (M), and the motor (M) is connected to the screw shaft (3). Shaft (1), a magnet (32) attached to the outer periphery of the shaft (1) via a yoke (31), a core (33) attached facing the magnet (32), and a core (33) ), The linear motion of the ball screw nut (4) is converted into the rotational motion of the screw shaft (3), and this rotational motion is converted into the shaft of the motor (M) ( 1) to generate an electromagnetic force in the motor (M), which is caused by the electromagnetic force. In the suspension device using a torque that resists the rotation of the shaft (1) as a damping force that suppresses the linear motion of the ball screw nut (4) by suppressing the rotational motion of the screw shaft (3). A hole for supplying and discharging gas into the air spring (C) is formed in the yoke (31) or the core (33), and the constant of the air spring (C) is changed by supplying and discharging gas into the air spring (C). The suspension device is characterized by simultaneously adjusting the vehicle height and cooling the motor. The mount (20) has a shock absorber (S) and an air spring (C). The mount (20) is a mount inner cylinder (21) and a mount outer cylinder disposed on the outer periphery of the mount inner cylinder (21). (22) and having a, the shock absorber (S) is the outer tube that is connected to the axle-side member (2), is connected to the vehicle body-side member while being slidably inserted into the outer cylinder (2) in An inner cylinder (5), a ball screw nut (4) provided on the bottom side in the outer cylinder (2), a screw shaft (3) rotatably engaged with the ball screw nut (4), A motor (M) connected to the upper end of the cylinder (5) via the mount inner cylinder (21) and to the screw shaft (3) is provided, and the air spring (C) is connected to the outer cylinder (2). ) and provided outside of the inner cylinder (5), the case where the motor (M) is housed in the mount inner tube (21) in ( 0), a shaft (1) connected to the screw shaft, a magnet (32) attached to the outer periphery of the shaft (1) via a yoke (31), and attached to face the magnet (32) It comprises a core (33) and a coil (34) fitted to the core (33), and converts the linear motion of the ball screw nut (4) into the rotational motion of the screw shaft (3). Is transmitted to the shaft (1) of the motor (M) to generate an electromagnetic force in the motor (M), and a torque that resists the rotation of the shaft (1) due to the electromagnetic force is applied to the screw shaft (3). ) In the suspension device that is used as a damping force that suppresses the linear motion of the ball screw nut (4) by suppressing the rotational motion of the mount inner cylinder (21), the case (30), and the York (31) or above In (33), a hole for supplying and discharging gas is formed in the air spring (C), and by changing the constant of the air spring (C) and adjusting the vehicle height by supplying and discharging gas into the air spring (C), A suspension device that cools a motor at the same time.   The suspension device according to claim 1, wherein an opening / closing valve is provided in the middle of the hole.

Images