JP2015033878A - Suspension for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension for a vehicle capable of providing both improvement in responsiveness and reduction in energy consumption.SOLUTION: A suspension for a vehicle includes a first connection member 5 which is connected to an axle housing 3 for holding an axle, an actuator 6 which is attached to a frame 4 for direct action driving of an output shaft 6a, a second connection member 7 connected to the output shaft 6a, and a speed conversion connection member 8 which is connected to the first connection member 5 and the second connection member 7, to raise a stroke speed of the second connection member 7 relative to the stroke speed of the first connection member 5.

Description

  The present invention relates to a vehicle suspension attached to a vehicle such as a truck or a bus.

  In recent years, active suspensions have been mounted as vehicle suspensions attached to vehicles such as trucks and buses. In the active suspension, a rod connected to an axle housing that holds an axle is driven and controlled by an actuator to reduce vibration of the vehicle body. Conventionally, an electromagnetic rotary motor is used as the actuator (see, for example, Patent Document 1).

JP-A-2005-090616

  By the way, the active suspension has an effect on a wider frequency band as the response of the actuator is higher when reducing vehicle vibration. However, the electromagnetic rotary motor has a problem in terms of responsiveness because time loss occurs from when electricity is turned on until the output shaft rotates.

  Therefore, it is conceivable to use a linear drive device represented by a linear motor as an actuator instead of an electromagnetic rotary motor. The linear drive device is not an electromagnetic motor that rotationally drives the output shaft like an electromagnetic rotary motor or the like, but an electromagnetic motor that linearly drives the output shaft.

  However, when a linear drive device is used as an actuator for an active suspension, there is a practical problem because the energy consumption of the actuator increases. In other words, the actuator of the linear motion drive device does not attenuate the rotational motion of the output shaft and convert it to linear motion like an electromagnetic rotary motor, but directly drives the output shaft to linear motion (linear motion). Therefore, the stroke speed of the actuator matches the stroke speed of the rod. In the motor, where the ratio of the internal resistance of the coil in the total energy consumption is large, the stroke speed of the linear drive device is lower than the rotational speed of the electromagnetic rotary motor. Compared with the actuator of the rotary motor, the internal resistance of the coil increases and the energy consumption increases.

  Therefore, an object of the present invention is to provide a vehicle suspension capable of improving both responsiveness and reducing energy consumption.

  A vehicle suspension according to the present invention includes a first connection member connected to a shaft support member that holds an axle, an actuator that is attached to a vehicle body and drives an output shaft to linearly move, and a second connection connected to the output shaft. And a speed conversion connecting member that is connected to the first connecting member and the second connecting member and increases the stroke speed of the second connecting member relative to the stroke speed of the first connecting member.

  According to the vehicle suspension of the present invention, since the first connection member and the second connection member are connected via the speed conversion connection member, the shaft support member and the first connection are connected via the speed conversion connection member. The stroke of the member and the strokes of the second connecting member and the output shaft can be transmitted to each other. And since the actuator which linearly drives an output shaft is used, the responsiveness of an actuator can be improved. Moreover, since the speed conversion connecting member increases the stroke speed of the second connecting member and the output shaft relative to the stroke speed of the first connecting member, the internal resistance of the actuator can be reduced. Thereby, the energy consumption of an actuator can be reduced.

  The speed conversion connecting member is rotatably connected to the vehicle body of the vehicle, and the first connecting member and the second connecting member are rotatably connected, and the speed conversion connecting member is rotated from the rotation center of the speed converting connecting member. The distance to the connection position of the conversion connection member and the second connection member may be longer than the distance from the rotation center of the speed conversion connection member to the connection position of the speed conversion connection member and the first connection member. it can. Thus, by making the speed conversion connecting member a link mechanism in which the first connecting member and the second connecting member are rotatably connected, the first connecting member, the second connecting member, and the output shaft of the actuator are connected. Stroke in conjunction with each other. The distance from the rotation center of the speed conversion connection member to the connection position of the speed conversion connection member and the second connection member is the connection between the rotation center of the speed conversion connection member and the speed conversion connection member and the first connection member. Since it is longer than the distance to a position, the stroke speed of the output shaft of a 2nd connection member and an actuator becomes high with respect to the stroke speed of a 1st connection member. Thereby, since the internal resistance of the actuator is reduced, the energy consumption of the actuator can be reduced.

  The speed conversion connecting member can convert the stroke direction of the first connecting member and the stroke direction of the second connecting member. Thus, since the speed conversion connecting member converts the stroke direction of the first connecting member and the stroke direction of the second connecting member, it is not necessary to stroke the output shaft in the same direction as the first connecting member. The degree of freedom of arrangement can be improved.

  In this case, the actuator can be attached in a direction in which the output shaft is linearly driven in the vehicle longitudinal direction. Since the vehicle is longer in the vehicle longitudinal direction than in the vehicle height direction, the actuator can be mounted on the vehicle by arranging the actuator so that the output shaft is linearly driven in the vehicle longitudinal direction.

  The actuator may be a linear motor. Thus, the response can be further improved by using the linear motor as the actuator.

  According to the present invention, both improvement in responsiveness and reduction in energy consumption can be achieved.

It is the schematic diagram which looked at the suspension for vehicles concerning an embodiment from the vehicles back side. It is the schematic diagram which looked at the suspension for vehicles concerning an embodiment from the vehicle right side. It is a figure which shows the operation state of the suspension for vehicles.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected about the element which is the same or it corresponds in each figure, and the overlapping description is abbreviate | omitted. In the following description, the vertical direction means the vertical direction of the vehicle, the longitudinal direction means the longitudinal direction of the vehicle, and the inside / outside direction means the inside / outside direction of the vehicle in the vehicle width direction.

  FIG. 1 is a schematic view of the vehicle suspension according to the embodiment as viewed from the vehicle rear side, and FIG. 2 is a schematic view of the vehicle suspension according to the embodiment as viewed from the right side of the vehicle. As shown in FIGS. 1 and 2, the vehicle suspension 1 according to the present embodiment is attached to a vehicle such as a truck or a bus and cancels the vibration in the vertical direction input from the wheels 2, thereby improving the riding comfort. Active suspension to improve. The vehicle suspension 1 is disposed between an axle housing 3 (axial support member) that rotatably holds an axle (not shown) to which wheels 2 are connected, and a frame 4 of the vehicle body. The vehicle suspension 1 is provided corresponding to each wheel 2 and cancels the vibration in the vertical direction input from each wheel 2. Since the vehicle suspension 1 provided corresponding to each wheel 2 has the same basic configuration, only the vehicle suspension 1 provided corresponding to one wheel will be described below.

  The vehicle suspension 1 includes a first connecting member 5, an actuator 6, a second connecting member 7, and a speed conversion connecting member 8.

  The first connecting member 5 is a member attached to the axle housing 3. The first connecting member 5 may be any member, for example, a rod extending linearly. In the present embodiment, the first connecting member 5 is described as a linearly extending rod.

  A joint 5a for connecting to the axle housing 3 is attached to one end of the first connecting member 5, and the first connecting member 5 is rotatably connected to the axle housing 3 via the joint 5a. Has been. The connection of the first connecting member 5 to the axle housing 3 may be performed directly or indirectly via a member such as a bracket attached to the axle housing 3. In the present embodiment, the first connecting member 5 is described as being directly connected to the axle housing 3.

  A joint 5b for connecting to the speed conversion connecting member 8 is attached to the other end of the first connecting member 5, and the first connecting member 5 is connected to the speed converting connecting member 8 via the joint 5b. It is connected freely. The connection of the first connection member 5 to the speed conversion connection member 8 may be performed directly or indirectly via a member such as a bracket attached to the speed conversion connection member 8. In the present embodiment, the first connecting member 5 is described as being directly connected to the speed conversion connecting member 8.

  The actuator 6 is a linear drive device that is attached to the frame 4 and linearly drives the output shaft 6a. Specifically, the actuator 6 includes a linear motor. In addition, the linear motion drive device does not attenuate the rotational motion of the output shaft and convert it into linear motion like an electromagnetic rotary motor, but directly drives the output shaft to linear motion (linear motion). . As the actuator 6, for example, various well-known linear motors that linearly drive the output shaft 6a can be employed.

  Here, since the actuator 6 is an electromagnetic actuator that linearly drives the output shaft 6a, the actuator 6 is formed long in the driving direction of the output shaft 6a. On the other hand, since the frame 4 (vehicle) is longer in the vehicle front-rear direction than in the vehicle height direction, a member that is longer in the vehicle up-down direction is less mountable on the frame 4. Therefore, the actuator 6 is attached to the frame 4 in a direction in which the output shaft 6a is linearly driven in the vehicle front-rear direction so that the mountability of the actuator 6 is improved. Thereby, the output shaft 6a is linearly driven by the actuator 6 in the vehicle front-rear direction.

  The drive control of the actuator 6 is not particularly limited, and can be performed by various methods. As an example of drive control of the actuator 6, a road surface shape detection device (not shown) mounted on the vehicle detects a road surface shape ahead of the wheels 2 in the vehicle front-rear direction, and outputs in accordance with the detected road surface shape. It can be performed by linearly driving the shaft 6a. For example, a well-known laser displacement meter (not shown) can be adopted as the road surface shape detection device, and the drive control of the actuator 6 can be realized by an ECU (not shown) mounted on the vehicle, for example. it can.

  The second connecting member 7 is a member connected to the output shaft 6 a of the actuator 6 and the speed conversion connecting member 8. The second connecting member 7 may be any member, for example, a rod extending linearly. In the present embodiment, the second connecting member 7 will be described as a linearly extending rod.

  A joint 7a for connecting to the output shaft 6a of the actuator 6 is attached to one end of the second connecting member 7, and the second connecting member 7 rotates with the output shaft 6a via the joint 7a. It is connected freely. The connection of the second connecting member 7 to the output shaft 6a may be performed directly or indirectly via a member such as a bracket attached to the output shaft 6a. In the present embodiment, description will be made assuming that the second connecting member 7 is directly connected to the output shaft 6a.

  A joint 7b for connecting to the speed conversion connecting member 8 is attached to the other end of the second connecting member 7, and the second connecting member 7 is connected to the speed converting connecting member 8 via the joint 7b. It is connected freely. The connection of the second connection member 7 to the speed conversion connection member 8 may be performed directly or indirectly via a member such as a bracket attached to the speed conversion connection member 8. In the present embodiment, the description will be made assuming that the second connecting member 7 is directly connected to the speed conversion connecting member 8.

  The speed conversion connecting member 8 is rotatably connected to the frame 4 to connect the first connecting member 5 and the actuator 6, and the stroke direction of the first connecting member 5 and the stroke of the second connecting member 7. It is a member that changes the direction.

  More specifically, a joint 8 a that is rotatably connected to the frame 4 is attached to the speed conversion connecting member 8. For this reason, the joint 8 a becomes the rotation center of the speed conversion connecting member 8. Further, the joint 5b is disposed on the opposite side of the actuator 6 with respect to the joint 8a in the vehicle longitudinal direction and on the upper side with respect to the joint 8a in the vehicle vertical direction. Further, the joint 7b is disposed on the actuator 6 side with respect to the joint 8a in the vehicle longitudinal direction and on the upper side with respect to the joint 8a in the vehicle vertical direction. As a result, the speed conversion connecting member 8 rotates, so that the first connecting member 5, the second connecting member 7, and the output shaft 6a are stroked in conjunction with each other. The stroke direction of the two connecting members 7 can be converted.

  The shape of the speed conversion connecting member 8 is not particularly limited, but can be formed, for example, in a substantially triangular plate shape. When the speed converting connecting member 8 is formed in a substantially triangular plate shape, the joint 5b of the first connecting member 5 and the joint 7a of the second connecting member 7 are connected to the two corners, respectively, and the remaining corners are connected. It is possible to connect the joint 8a.

  FIG. 3 is a diagram showing an operating state of the vehicle suspension. As shown in FIGS. 3A and 3B, in the speed conversion connecting member 8, the distance B from the joint 8a to the joint 7b is longer than the distance A from the joint 8a to the joint 5b. The joint 5b is located at the connection position between the speed conversion connecting member 8 and the first connection member 5, and the joint 7b is located at the connection position between the speed conversion connecting member 8 and the second connection member 7. The joint 8 a is located at the rotation center of the speed conversion connecting member 8.

  Next, the operation principle of the vehicle suspension 1 will be described in detail.

  Since the first connecting member 5 connects the axle housing 3 and the speed conversion connecting member 8, when the first connecting member 5 strokes up and down due to vibrations input from the wheels 2, the joint 5 b The same displacement as the stroke of the first connecting member 5 is displaced with respect to the joint 8a (rotation center), and the joint 7b is displaced in conjunction with the displacement of the joint 5b. And since the 2nd connection member 7 has connected between the output shaft 6a and the speed conversion connection member 8, the displacement of this joint 7b is transmitted to the 2nd connection member 7 and the output shaft 6a, and the 2nd connection member. 7 and the output shaft 6 a stroke in synchronization with the stroke of the first connecting member 5.

  At this time, since the joint 7b rotates around the joint 8a, the second connecting member 7 strokes in the vehicle front-rear direction while slightly moving in the vehicle vertical direction. However, since the joint 7a and the joint 7b attached to both ends of the second connecting member 7 are rotatably connected to the speed conversion connecting member 8 and the output shaft 6a, the output shaft 6a is connected to the vehicle in the vertical direction. The stroke can be made without being displaced.

  On the other hand, when the actuator 6 linearly drives the output shaft 6a and the second connecting member 7 strokes in the vehicle front-rear direction, the joint 7b has the same stroke as the second connecting member 7 with respect to the joint 8a (rotation center). The joint 5b is displaced in conjunction with the displacement of the joint 7b. Then, the displacement of the joint 7 b is transmitted to the first connecting member 5, and the axle housing 3 and the wheel 2 stroke in synchronization with the stroke of the second connecting member 7.

  By the way, the relationship between the stroke X of the first connecting member 5 and the stroke Y of the second connecting member 7 and the output shaft 6a is that A (distance from the joint 8a to the joint 5b) and B (joint 8a) in the speed conversion connecting member 8. To the joint 7b). Since the speed conversion connecting member 8 has a relationship of A <B, the stroke speeds of the second connecting member 7 and the output shaft 6a are higher than the stroke speed of the first connecting member 5. That is, the strokes of the second connecting member 7 and the output shaft 6 a are increased with respect to the stroke of the first connecting member 5.

Ｒ：コイルの内部抵抗
ｉ：電流
Ｅ：外乱のエネルギー
φ：推力係数
ｖ：ストローク速度
式１から分かるように、コイルの内部抵抗Ｒｉ^２は、アクチュエータ６のストローク速度ｖの２乗に反比例する。このため、アクチュエータ６のストローク速度が高いほど、コイルの内部抵抗Ｒｉ^２が低くなって、アクチュエータ６の消費エネルギーが低減する。 Here, the ratio of the internal resistance of the coil to the entire energy consumption of the actuator 6 is large, and the internal resistance Ri ^{2 of the} coil is expressed by the following equation 1.

R: Coil internal resistance i: Current E: Disturbance energy φ: Thrust coefficient v: Stroke speed As can be seen from Equation 1, the internal resistance Ri ^{2 of the} coil is inversely proportional to the square of the stroke speed v of the actuator 6. For this reason, the higher the stroke speed of the actuator 6, the lower the internal resistance Ri ^{2 of the} coil and the lower the energy consumption of the actuator 6.

Therefore, in the present embodiment, as described above, the speed conversion connecting member 8 is set to have a relationship of A <B, and the stroke of the second connecting member 7 and the output shaft 6a is increased with respect to the stroke of the first connecting member 5. ing. Thus, as compared with the case the stroke speed of the first coupling member 5 and the second connecting member 7 are the same, since the internal resistance Ri ² coils in the case of the same work is lower, the energy consumption of the actuator 6 Is reduced.

  Next, an example of drive control of the actuator 6 in the vehicle suspension 1 will be briefly described.

  First, a road surface shape detection device (not shown) detects a road surface shape ahead of the wheels 2 in the vehicle front-rear direction.

  Then, the ECU (not shown) drives and controls the actuator 6 so that the first connecting member 5 strokes in a direction that cancels the vibration in the vehicle vertical direction input from the wheels 2. Note that the drive control amount of the actuator 6 is appropriately set depending on the amount of road surface unevenness detected by the road surface shape detection device.

  Then, the vehicle vertical vibration input from the wheel 2 is transmitted to the output shaft 6 a via the axle housing 3, the first connecting member 5, the speed conversion connecting member 8 and the second connecting member 7. When the output shaft 6a is linearly driven, the displacement transmitted to the output shaft 6a is absorbed. Thereby, the vibration of the vehicle body can be reduced.

  As described above, according to the vehicle suspension 1 according to the present embodiment, the first connecting member 5 and the second connecting member 7 are connected via the speed conversion connecting member 8. The stroke of the first connecting member 5 and the stroke of the second connecting member 7 and the output shaft 6a can be transmitted to each other. Further, since the actuator 6 that linearly drives the output shaft 6a is used, the responsiveness of the actuator 6 can be improved. Moreover, since the speed conversion connecting member 8 increases the stroke speed of the second connecting member 7 and the output shaft 6a with respect to the stroke speed of the first connecting member 5, the internal resistance of the actuator 6 can be reduced. . Thereby, the energy consumption of the actuator 6 can be reduced.

  Moreover, the speed conversion connecting member 8 is a link mechanism in which the first connecting member 5 and the second connecting member 7 are rotatably connected, so that the first connecting member 5, the second connecting member 7, and the actuator 6 can be connected. The output shaft 6a strokes in conjunction with each other. And the distance from the rotation center (joint 8a) of the speed conversion connection member 8 to the connection position (joint 7b) of the speed conversion connection member 8 and the second connection member 7 is the rotation center of the speed conversion connection member 8 ( Since the distance from the joint 8a) to the connecting position (joint 5b) between the speed conversion connecting member 8 and the first connecting member 5 is longer, the second connecting member 7 and the actuator 6 with respect to the stroke speed of the first connecting member 5 are used. The stroke speed of the output shaft 6a increases. Thereby, since the internal resistance of the actuator 6 is reduced, the energy consumption of the actuator 6 can be reduced.

  Moreover, it is necessary to stroke the output shaft 6 a in the same direction as the first connecting member 5 by changing the direction of the stroke of the first connecting member 5 and the stroke direction of the second connecting member 7 by the speed conversion connecting member 8. Since there is no need, the degree of freedom of arrangement of the actuator 6 can be improved.

  Further, since the vehicle is longer in the vehicle front-rear direction than in the vehicle height direction, the actuator 6 is arranged so that the output shaft 6a is linearly driven in the vehicle front-rear direction, thereby improving the mountability of the actuator 6 on the vehicle. Can be made.

  Further, by using a linear motor as the actuator 6, the responsiveness can be improved as compared with the case where another linear drive device is used as the actuator 6.

  The preferred embodiment of the present invention has been described above, but the present invention is not limited to the above embodiment.

  For example, in the above embodiment, the actuator has been described as using a linear motor, but other actuators may be used as long as they are linear drive devices that drive the output shaft linearly.

  Moreover, in the said embodiment, although the speed conversion connection member was demonstrated as what was formed in the substantially triangular substantially flat plate shape, making the stroke speed of a 2nd connection member high with respect to the stroke speed of a 1st connection member. Any shape and mechanism may be used as long as they can.

  Moreover, although the specific positional relationship of the joint 5b, the joint 7b, and the joint 8a was demonstrated in the said embodiment, these positional relationships are not specifically limited, It is 1st with respect to the stroke speed of a 1st connection member. Any positional relationship is possible as long as the stroke speed of the two connecting members can be increased.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle suspension, 2 ... Wheel, 3 ... Axle housing (shaft support member), 4 ... Frame, 5 ... First connection member, 5a ... Joint, 5b ... Joint, 6 ... Actuator, 6a ... Output shaft, 7 ... 2nd connection member, 7a ... Joint, 7b ... Joint, 8 ... Speed conversion connection member, 8a ... Joint.

Claims (5)

A first connecting member connected to a shaft support member holding the axle;
An actuator attached to the vehicle body to drive the output shaft directly;
A second connecting member connected to the output shaft;
A speed conversion connecting member connected to the first connecting member and the second connecting member to increase a stroke speed of the second connecting member with respect to a stroke speed of the first connecting member;
A vehicle suspension comprising: The speed conversion connecting member is
The first connecting member and the second connecting member are rotatably connected to the vehicle body of the vehicle,
The distance from the rotation center of the speed conversion connection member to the connection position of the speed conversion connection member and the second connection member is the distance from the rotation center of the speed conversion connection member to the first connection. Longer than the distance to the connecting position with the member,
The vehicle suspension according to claim 1. The speed conversion connecting member converts a stroke direction of the first connecting member and a stroke direction of the second connecting member.
The vehicle suspension according to claim 1 or 2. The actuator is attached in a direction in which the output shaft is linearly driven in the vehicle longitudinal direction.
The vehicle suspension according to claim 3. The actuator is a linear motor.
The suspension for vehicles as described in any one of Claims 1-4.

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