JPH1047405A - Vehicular suspension device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality and durability of a suspension device utilizing electromagnetic force caused by a magnet and a coil. SOLUTION: An air spring device comprises an upper case 23 of which upper end portion is fixed to a piston rod 13 and supported through an upper support 26 on a vehicle body BD, a lower case 24 of which lower end portion is fixed on the outer periphery of an outer cylinder 11, and a connecting case 25 made of a diaphragm which connects the upper case 23 and the lower case 24 together to define an air chamber R4 inside the upper case 23. A coil assembly which houses therein a plurality of coils 42 is fixed on the inner periphery of the upper case 23 at the lower portion. A cylindrical support member 35 is erected on the upper end portion of the lower case 24, and magnets 36 and 31 are fixed on the outer periphery of the support member 35 to face the coils 42. The electromagnetic force caused by the coils 42 and the magnets 36 and 37 is utilized to restrict the vertical relative motion of the body BD to a lower arm LA.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension apparatus for a vehicle that regulates or controls a vertical movement of a sprung member with respect to a unsprung member by using an electromagnetic force generated by a magnet and a coil.

[0002]

2. Description of the Related Art Conventionally, this type of apparatus is disclosed in
As shown in JP-A-44758, a coil is arranged between an outer cylinder and an inner cylinder that constitute a damper device, and an outer peripheral surface of a piston in an inner cylinder and an outer cylinder of the inner cylinder that constitute the damper device. A permanent magnet is arranged on the outer peripheral surface so as to face the coil,
By controlling the energization of the coil, the vehicle height is adjusted, and a damping force is applied to the vertical vibration of the unsprung member with respect to the sprung member.

[0003]

However, in the above-mentioned conventional apparatus, since the magnet and the coil are arranged inside the outer cylinder, that is, in the working fluid, friction powder in the working fluid adheres to the magnet. As a result, the outer peripheral surface of the magnet and the inner peripheral surface of the inner cylinder are worn, and the characteristics of the electromagnetic force change due to a rise in the temperature of the hydraulic fluid. Further, since a magnet is also provided outside the outer cylinder and the outside is kept open to the outside, iron powder and other powder from the outside adhere to the magnet, and the inner peripheral surface of the magnet and the outer peripheral surface are separated from each other. The outer peripheral surface of the cylinder is worn. Further, since magnetic lines of force pass through the inner cylinder and the outer cylinder, both cylinders need to be made of a non-magnetic material and a certain degree of strength is required, which increases the material cost of both cylinders.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to address the above problems, and has as its object to provide a low-cost, high-quality suspension device.

In order to achieve this object, a structural feature of the present invention is that the damper device is arranged inside the case of the air spring device and facing the outside of the cylinder of the damper device. There is provided a magnet and a coil which are respectively displaced integrally with the cylinder and the piston rod.

According to this suspension device, since both the magnet and the coil are disposed outside the cylinder and in the air that is isolated from the outside, there is also a problem that the suspension is disposed in the hydraulic fluid in the conventional device. Also, the problem of exposure to the outside air is solved, and both the quality and durability are improved. In addition, since the required magnetic field lines do not pass through the cylinder, the cylinder can be manufactured from a low-cost material such as iron.
Furthermore, the air in the air spring device is usually air that has passed through devices such as an air filter and a drier, and the environmental conditions in which the magnet and the coil are arranged are good, so that the characteristics of the magnet and the coil are always kept good. As well as durability.

Another structural feature of the present invention is that the case is formed in a cylindrical shape with an upper end fixed to the outer peripheral surface of the piston rod and elastically supported by a sprung member. A case, a lower case formed in a cylindrical shape and having a lower end fixed to the outer peripheral surface of the cylinder, and a connection case configured to be a sheet of a material that is easily deformed and connecting the upper case and the lower case, One of the magnet and the coil is fixed to the upper case, and the other of the magnet and the coil is fixed to the lower case.

According to this, even if the inclination of the cylinder with respect to the sprung member changes, the piston rod also tilts together with the cylinder, the upper case interlocks with the piston rod, and the lower case tilts integrally with the cylinder. Therefore, the distance between the magnet and the coil fixed to the upper case and the lower case, respectively, is always kept constant, and the characteristics of the magnetic force generated by the magnet and the coil are always kept constant.

Another structural feature of the present invention is that the upper portion of the lower case is supported on the outer peripheral surface of the cylinder. According to this, the lower case is further displaced integrally with the cylinder, and the distance between the magnet and the coil is more accurately kept constant.

[0010] Further, another structural feature of the present invention is that the case is formed in a cylindrical shape and an upper surface thereof is supported by a sprung member. Consists of a lower case fixed to the outer peripheral surface and a connection case that is made of a deformable material in a sheet shape and connects the upper case and the lower case. A cylindrical support member is separated from the cylinder at the upper end of the lower case. And one of the magnet and the coil is fixed to the inner peripheral surface of the upper case, and the other of the magnet and the coil is fixed to the outer peripheral surface of the support member, and a radial through hole is formed in the support member. And the coil is provided so as to open to the opposing surface.

According to this, even when the opposing surfaces of the magnet and the coil are brought close to each other, the air flow flowing in the case of the air spring device when the sprung member vibrates against the unsprung member is transmitted through the through-hole to the opposing surface. It will flow in between. Therefore,
Even if the magnet surface and the coil surface adhere to each other due to the difference in inclination between the upper case and the lower case, they are separated by the air flow, so that the distance between the magnet and the coil can be reduced to obtain a large magnetic force. Will be able to

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows the whole suspension device of a vehicle in a partially cutaway view, and FIG. Is shown. This suspension device includes a damper device disposed between a vehicle body BD as a sprung member and a lower arm LA as a unsprung member, and an air spring device provided on an outer periphery of the damper device.

The damper device comprises an outer cylinder 11 and an inner cylinder 12, which are coaxially arranged,
1 and 12 are provided with a piston rod 13 assembled so as to be able to advance and retreat in the axial direction. The outer cylinder 11 is attached at its lower end to the lower arm LA via a bush (not shown). The inner cylinder 12 is connected to the outer cylinder 11 via an annular support plate 14 at the upper end thereof.
Are supported in a liquid-tight manner on an upper inner peripheral surface of the outer cylinder 11, and are supported on a lower inner peripheral surface of the outer cylinder 11 via a supporting member (not shown) at a lower end thereof. The piston rod 13 extends upward from the outer cylinder 11, and is attached to the vehicle body BD at its upper end via an upper support 16 fixed to the vehicle body BD by screws 15,15.
The upper support 16 contains an elastic material such as rubber, and allows a slight change in the inclination of the piston rod 13 with respect to the vehicle body BD.

The interior of the inner cylinder 12 is divided into upper and lower chambers R1 and R2 by a main piston 17 fixed to the outer peripheral surface of the piston rod 13 and sliding on the inner peripheral surface of the inner cylinder 12 in a liquid-tight manner in the axial direction. ing. Upper and lower chambers R1, R
Reference numeral 2 is filled with hydraulic fluid (hydraulic oil), and the lower chamber R2 communicates with an annular chamber R3 formed between the outer cylinder 11 and the inner cylinder 12 at the lower end of the inner cylinder 12. Gas is also sealed in the annular chamber R3.
Reference numeral 3 denotes an inner cylinder 1 accompanying the reciprocation of the piston rod 13.
A change in volume of the hydraulic fluid in the upper and lower chambers R1 and R2 is absorbed.

The main piston 17 has upper and lower chambers R1, R2.
Is provided, and the orifice generates a damping force as the piston rod 13 moves up and down. A sub-piston 18 is fixed to the outer peripheral surface of the piston rod 13 below the main piston 17 with some clearance provided between the sub-piston 18 and the inner peripheral surface of the inner cylinder 12. Sub piston 18
A variable orifice (not shown), which connects the upper and lower chambers R1 and R2, is provided therein, and the opening of the variable orifice is switched by a damping force switching actuator 21 provided at the upper end of the piston rod 13. It is supposed to be. A valve member (not shown) for adjusting the opening of the variable orifice is driven by an actuator 21 via a connection mechanism provided in the piston rod 13. Above the main piston 17 and on the outer periphery of the piston rod 13, a rebound stopper 22 is assembled, and the stopper 22 causes the upward displacement of the piston rod 13 caused by the rebound of the vehicle body BD to move with the support plate 14. The contact is elastically regulated.

The air spring device has a cylindrical upper case 23.
And a lower case 24 and a connecting case 25 for airtightly connecting the two cases 23, 24.
Outer cylinder 11 and piston rod 1
An air chamber R4 is formed on the outer periphery of the air chamber R3. This air chamber R
An electrically controlled intake and exhaust device (not shown) is connected to 4, so that the amount of air in the same room R4 is adjusted.

The upper case 23 is formed of a flexible resin. The upper case 23 is supported on the vehicle body BD via an upper support 26 and a support plate 27 on the upper surface thereof, and the piston rod 13 is supported via the support plate 27. Is hermetically fixed on the outer peripheral surface of the upper end portion of the upper case. The upper support 26 contains an elastic material such as rubber and allows a slight change in the inclination of the upper case 23 with respect to the vehicle body BD. A rubber-made bound stopper 28 is attached to the lower surface of the support plate 27, and the stopper 28 abuts against an annular stopper plate 31 fixed to the upper surface of the outer cylinder 11 to elastically bounce the vehicle body BD. regulate. The lower case 24 is also formed of resin, and is hermetically fixed on the inner peripheral surface of the lower portion on the outer peripheral surface of the cylindrical member 32 welded and fixed on the outer peripheral surface of the outer cylinder 11. The connection case 25 is formed of a diaphragm mainly made of elastic rubber, and is hermetically fixed on an outer peripheral surface of a lower end portion of the upper case 23 by a caulking ring 33 at an upper end thereof. It is hermetically fixed on the upper outer peripheral surface of the lower case 24 by a caulking ring 34.

A support member 35 formed of a non-magnetic material in a cylindrical shape is fixed upright on the upper end surface of the lower case 24.
On the outer peripheral surface of the member 35, an annular magnet (permanent magnet) 3
6, 37 are fixed. The lower end surface of the magnet 36 and the upper end surface of the magnet 37 are connected to one of the magnetic poles (for example, S pole).
And the lower end surface of the magnet 37 are connected to the other magnetic pole (for example, N
Pole). An annular rib 38 is fixed on the inner peripheral surface of the upper end portion of the support member 35, and the rib 38 abuts on the outer peripheral surface of the stopper plate 31 on its inner peripheral surface. The upper end of the cylinder 11 is supported separately from the outer peripheral surface. Also,
A plurality of holes 38a communicating vertically are provided at appropriate plural positions in the circumferential direction of the rib 38, and communicate the upper and lower chambers of the stopper plate 31 with each other.

On the outer peripheral surfaces of these magnets 36 and 37,
A cylindrical coil assembly is provided facing the magnets 36 and 37. The coil assembly has a casing 41 formed of resin in a cylindrical shape. On the inner peripheral surface of the casing 41, a plurality of coils 42 (C1 to C15) whose axial direction is the extending direction of the piston rod 13 are arranged at equal intervals along the axial direction via resin spacers 43, respectively. Are located. The coil 42 is led out of the upper case 23 via a lead wire 42a. A coating layer 44 coated with a slippery resin such as Teflon is provided on the inner peripheral surface of the spacer 43, and the coating layer 44 is formed by coating the same resin on the outer peripheral surface of each upper end of the lower case 24 and the support member 35. 45, 46, the coating layer 4
Even when the coating layer 4 and the coating layers 45 and 46 come into contact with each other, the frictional force is reduced. Note that ribs 47 are provided at appropriate locations in the circumferential direction on the inner peripheral surface of the upper case 23, and support the casing 41 on the inner peripheral surface of the upper case 23 at appropriate locations.

The coil assembly composed of the casing 41, the coil 42 and the spacer 43 thus configured is
At the time of caulking the connection case 25 to the upper case 23 by the caulking ring 33, the rubber sheet 4 formed into a cylindrical shape is used.
8 and is fixed on the inner peripheral surface of the upper case 23. In this case, even if the upper case 23 and the casing 41 creep somewhat, the coil assembly is firmly and durably fixed on the inner peripheral surface of the upper casing 23 by the elasticity of the rubber sheet 48.

Next, an electric control device for controlling the suspension device configured as described above will be described. FIG. 3 is a block diagram showing the entire electric control device.

This electric control device comprises a steering angle sensor 51, a vehicle height sensor 52, a lateral acceleration sensor 53 and a vehicle speed sensor 54.
It has. The steering angle sensor 51 detects a rotation angle of a steering wheel (not shown) as a steering angle θf,
A detection signal representing the steering angle θf is output. The vehicle height sensor 52 is provided between the vehicle body BD and the lower arm LA, and detects the height of the vehicle body BD with respect to the lower arm LA to the vehicle height HT.
And outputs a detection signal indicating the vehicle height HT. The lateral acceleration sensor 53 is attached to the vehicle body BD, detects a lateral acceleration of the vehicle body BD as a lateral acceleration Gy, and outputs a detection signal representing the lateral acceleration Gy. The vehicle speed sensor 54 detects the vehicle speed V and outputs a detection signal indicating the vehicle speed V.

Each of these sensors 51 to 54 is connected to a microcomputer 55. The microcomputer 55 controls the suspension device by executing a program described later, and controls the vehicle height and the damping force. The microcomputer 55 includes a drive circuit 56 for controlling the vehicle height and a drive circuit 57 for switching the damping force.
And a drive circuit 58 for energizing the coil 42 is connected to each other. The drive circuit 56 includes a vehicle height control actuator 6 provided in an intake and exhaust device (not shown) for controlling the supply and exhaust of air to and from the air chamber R4.
0 is drive-controlled. The drive circuit 57 controls the drive of the actuator 21 for switching the damping force.

The drive circuit 58 controls the energization and non-energization of the plurality of coils 42. As shown in FIG. 4, each of the coils 42 (labeled C1 to C15 from top to bottom).
And four transistors Tr1 to Tr4. The transistors Tr1 and Tr2 are of the PNP type, and the transistors Tr3 and Tr4 are of the NPN type. The transistors Tr3 and Tr4 are connected in series between the power supply + V and the ground, and each coil is connected to each connection point of the transistors Tr1 and Tr3 and Tr2 and Tr4. 4
2 are connected to each other. In this case, when a control voltage is applied to the transistors Tr1 and Tr4 to turn on both the transistors Tr1 and Tr4 at the same time, a current flows in the direction indicated by the solid line in the drawing, and the magnetic flux passes through the coil 42 from below to above (the coil 42 The upper part is equivalent to a magnet magnetized to the north pole and the lower part is magnetized to the south pole.) On the other hand, when a control voltage is applied to the transistors Tr2 and Tr3 to turn on both the transistors Tr2 and Tr3 at the same time, a current flows in the direction of the dashed arrow in the drawing, and the magnetic flux passes through the coil 42 from above to below (coil 4
The upper part of 2 is equivalent to a magnet magnetized to the south pole and the lower part to the north pole). Hereinafter, the former energization state is called forward energization, and the latter energization state is called reverse energization.

Next, the operation of the suspension device configured as described above will be described in the order of vehicle height adjustment, damping force switching, and energizing / deenergizing control of the coil 42.

The vehicle height adjustment is performed by executing a vehicle height adjustment program (not shown). Microcomputer 55
Executes the vehicle height adjustment program every predetermined short time, determines whether the vehicle height HT input from the vehicle height sensor 52 is higher or lower than a predetermined reference vehicle height, and determines the same. , The actuator 60 for controlling the vehicle height is controlled via the drive circuit 56. If the detected vehicle height HT is higher than the reference vehicle height, the vehicle height control actuator 60 discharges the air in the air chamber R4 of the air spring device. This exhaust reduces the air pressure in the air chamber R4, lowers the upper case 23 and the piston rod 13, and lowers the vehicle body BD.
On the other hand, if the detected vehicle height HT is lower than the reference vehicle height, the vehicle height control actuator 60 supplies air into the air chamber R4 of the air spring device. By this air supply, the air pressure in the air chamber R4 increases, and the upper case 23 and the piston rod 13
Rise, and the vehicle body BD also rises. As a result, the height of the vehicle body BD with respect to the lower arm LA is always kept substantially constant.

On the other hand, even if an external force is applied to the vehicle body BD from the road surface, the air spring device filled with air in the air chamber R4 absorbs the applied external force and reduces the impact on the vehicle body BD. The ride comfort is good.

Next, the switching control of the damping force will be described. This control is performed by executing a damping force switching program consisting of steps 100 to 120 in FIG.
The microcomputer 55 repeatedly executes this program every predetermined short time. After the start in step 100, in step 102, the microcomputer 55 outputs detection signals representing the vehicle speed V and the lateral acceleration Gy from the vehicle speed sensor 54 and the lateral acceleration sensor 53, respectively. Then, the actuator 21 for switching the damping force is controlled in accordance with the vehicle speed V and the lateral acceleration Gy with reference to the V-Gy map incorporated in the computer 55 through the processing of steps 104 to 118. V-Gy
As shown in FIG. 6, the map includes two characteristic curves L1 and L2 in which the lateral acceleration Gy decreases as the vehicle speed V increases.
Is stored.

When the coordinate point determined by the vehicle speed V and the lateral acceleration Gy is in the upper region of the characteristic curve L1 of FIG. 6, the microcomputer 55 executes the processing of steps 104 to 108 to set the damper device to the soft state (first flag). FLG1 is “0”) on the condition that the driving circuit 56
, The actuator 21 is switched to the hardware side and controlled. The actuator 21 drives the valve member in the sub-piston 18 to set the opening of the variable orifice small, and switches the damper device to the hard state. The hardware state of the damper device is maintained until the coordinate point determined by the vehicle speed V and the lateral acceleration Gy is in the lower area of the characteristic curve L2 in FIG. When the coordinate point determined by the vehicle speed V and the lateral acceleration Gy is in the lower region of the characteristic curve L2 in FIG.
The microcomputer 55 performs steps 112 to 118
With the above-described processing, the actuator 21 is switched to the software side via the drive circuit 56 and controlled under the condition that the damper device is in the hard state (the first flag FLG1 is “1”). The actuator 21 drives the valve member in the sub-piston 18 to set the opening of the variable orifice large, and switches the damper device to a soft state. This soft state of the damper device is maintained until the coordinate point determined by the vehicle speed V and the lateral acceleration Gy is in the upper region of the characteristic curve L1 in FIG. 6 (see FIG. 9).

By the switching control of the damping force as described above, the damping force of the damper device is selectively switched between software and hardware according to the running state of the vehicle. Therefore,
The input from the road surface, the change in the posture of the vehicle body BD, the vehicle body BD
Is vibrated up and down, this vibration is suppressed according to the traveling state of the vehicle by the damping force of the damper device. Specifically, when the vehicle speed V and the lateral acceleration Gy are small, the damping force is kept small, so the ride comfort of the vehicle is emphasized. on the other hand,
When the vehicle speed V or the lateral acceleration Gy is large, the damping force is kept large, so that a change in the posture of the vehicle during a sharp turn or the like is suppressed, and the stability of the vehicle is improved.

Next, control of energization and non-energization of the coil 42 will be described.
This is performed by executing the energization / de-energization control program consisting of 152. The microcomputer 55 repeatedly executes this program every predetermined short time, and
After the start of 0, in step 132, respective detection signals representing the steering wheel angle θf and the vehicle height HT are input from the steering angle sensor 51 and the vehicle height sensor 52, respectively, and in step 134, the detected steering wheel angle θf is differentiated with time. The steering angular velocity θ
f ′ (= dθf / dt) is calculated, and the energization of the coil 42 is controlled by the processing of steps 136 to 150.

First, if the absolute value | θf ′ | of the steering angular velocity θf is smaller than the predetermined first reference value θf1, step 136 is executed.
Is determined to be “NO”, and in step 144, it is determined whether or not the second flag FLG2 is “1”. The second flag FLG2 indicates the non-energized state of the coil 42 by "0" and the energized state of the coil 42 by "1".
Initially, it is set to “0”. Therefore, first, at step 144, “NO” is determined, and the program proceeds to step 150.
Is kept off.

In this state, when the driver turns the steering wheel, the absolute value | θf ′ | of the steering angular velocity θf becomes the first reference value θ.
If f1 or more, it is determined "YES" in step 136, the program proceeds to step 138, and in step 138, the energization control of the coil corresponding to the vehicle height HT is performed based on the energization map built in the computer 55. I do. As shown in FIG. 8, the energization map corresponds to the upper and lower positions of the coil 42 relative to the magnets 36 and 37, and the coil 42 to be energized in the forward direction among all the coils 42 (C1 to C15). The coil 42 to be energized in the opposite direction is shown. In this case, the length of each of the magnets 36 and 37 is set substantially equal to the width of three coils 42, and specifically,
As for the magnet 36, the three coils 42, which are shifted upward by one from the three coils 42 facing each other, are energized in the opposite direction. As for the magnet 37, three coils 42 shifted one by one below the three coils 42 facing each other.
Are energized in the forward direction.

In this case, the relative position of the coil 42 with respect to the magnets 36 and 37 corresponds to the height of the vehicle body BD with respect to the lower arm LA, and this relative height is detected as the vehicle height TH. The coil 42 to be energized can be determined based on the vehicle height TH. The vertical axis in FIG. 8 represents the reference height position of the vehicle body BD with respect to the lower arm LA as “0”, and the side higher than the reference height (extension side of the damper device) is sequentially represented as + a1, + a2, + a3. The lower side (the contracting side of the damper device) is sequentially -a1, -a2, -a
3, -a4. Therefore, as the vehicle body BD becomes higher with respect to the lower arm LA, the energized coil 42 becomes lower in order from the higher coil 42, that is, the coils C1 to C1.
Move to the 5 side.

When the coil 42 is energized through the drive circuit 58 as described above in step 138,
The magnetic poles caused by the forward and reverse energization of the coil 42 are shown in FIG.
The coil 42 and the upper case 23 (on the sprung member side) to which the coil 42 is fixed receive a force to maintain the coil 42 and the magnets 36 and 37 at the position shown in FIG. Works. That is, if the coil 42 and the upper case 23 to which the coil 42 is fixed are slightly displaced up and down from the illustrated position, a force acts to return them to the illustrated position. After the processing in step 138, the processing in steps 140 and 142 causes the second flag FLG2
If is not "0", it is changed to "1".

The absolute value | θf ′ | of the calculated steering angular velocity θf is equal to a predetermined second reference value θf2 (θf2 <θf
1) As long as it is above, based on the determination of “YES” in both steps 144 and 146, the coil 42 corresponding to the vehicle height HT is controlled through the drive circuit 58 based on the power supply map in step 138. Is done. However, as described above, when the vehicle height HT changes, the changed vehicle height H
The coil 42 is energized corresponding to T.

On the other hand, when the calculated absolute value | θf ′ | of the steering angular velocity θf becomes smaller than the second reference value θf2, step 1 is executed.
The determination at 46 is "NO" and the program proceeds to step 14
Proceed to 8,150. In step 148, the second flag FLG2 is returned to "0", and in step 150, the energization to the coil 42 is released. Then, the absolute value | θf ′ | of the steering angular velocity θf becomes the first reference value θf1 again.
Until the above, the coil 42 is maintained in the non-energized state.

As described above, the absolute value | θf ′ of the steering angular velocity θf
Is small, the coil 42 is kept in a non-conductive state, and the upper case 23 is provided with the magnets 36 and 37 and the coil 42.
The force to maintain the current position due to the electromagnetic force does not work. Therefore, in this state, when an external force from the road surface acts on the vehicle body BD, the vehicle body BD can move up and down relatively freely with respect to the lower arm LA, and the air spring device reduces the external force by a repulsive action. Therefore, the riding comfort of the vehicle is kept good. Also, when the vehicle turns sharply due to a sharp turn of the steering wheel, the absolute value | θf ′ | of the steering angular velocity θf increases as shown in FIG.
Since the force for maintaining the current position due to the electromagnetic force acts on the vehicle body, the change in the posture of the vehicle body BD is suppressed, and the stability of the vehicle is improved. The force for maintaining the vehicle body BD at the current position by the electromagnetic force between the magnets 36 and 37 and the coil 42 is not due to the generation of the relative speed of the vehicle body BD with respect to the lower arm LA unlike the damper device. Since the driver can immediately respond to the driving operation of the driver, the control responsiveness of the suspension device can be improved.

In the present embodiment, the switching of the damping force is controlled in accordance with the lateral acceleration Gy as the posture information of the vehicle body BD, and the energization and non-energization of the coil 42 are controlled by the steering angular velocity θf as the driving operation information. 'To control according to. However, by reversing these controls, the switching of the damping force is controlled in accordance with the steering angular velocity θf ′ as the driving operation information, and the coil 42 is switched.
May be controlled according to the lateral acceleration Gy as posture information of the vehicle body BD. Further, as the posture information of the BD of the vehicle body, various physical movement quantities such as the lateral speed, the longitudinal acceleration, the longitudinal speed, the yaw rate, the vertical acceleration, and the vertical speed of the vehicle body BD may be used for controlling the two. Further, a driving operation amount such as a steering angle of the steering wheel, a stepping speed of a brake, a stepping speed of an accelerator pedal, and a throttle opening may be used for the control of the two.

As can be understood from the above description, according to the above-described embodiment, both the magnets 36 and 37 and the coil 42 are outside the outer cylinder 12 and inside the cases 23 to 25 of the air spring device which are cut off from the outside. Since they are arranged in the air, the magnets 36 and 37 and the coil 42 are protected without being affected by the working fluid and the dirt and powder in the outside world, and the suspension apparatus has high quality and good durability. Also, since the required magnetic lines of force do not pass through the outer cylinder 11 and the inner cylinder 12, both cylinders 1
1 and 12 can be manufactured from low-cost materials such as iron. Further, the air in the air spring device is usually air that has passed through devices such as an air filter and a drier, and the environmental conditions in which the magnets 36 and 37 and the coil 42 are arranged are good.
6, 37 and the characteristics of the coil 42 are always kept good, and the durability is also improved.

Even if the inclination of the outer cylinder 11 with respect to the vehicle body BD changes, the upper case 23 is fixed to the piston rod 13 via the support plate 27, and is elastically supported by the vehicle body BD by the upper support 26. Therefore, the upper case 23 also tilts in conjunction with the piston rod 13 whose tilt changes with the outer cylinder 11. Further, since the lower case 24 is supported on the outer periphery of the outer cylinder 11 at two points above and below the support member 32, the rib 38 and the bound stopper 31, the lower case 32 also tilts together with the outer cylinder 11. Therefore,
The upper case 23 and the lower case 24 are also inclined integrally, and the distance between the coil 42 fixed to the upper case 23 and the lower case 24 and the magnets 36 and 37 is always kept constant and generated by the magnet and the coil. The magnetic force characteristics are always kept constant.

Next, a modified example in which a part of the suspension device of the above embodiment is modified will be described with reference to the drawings. FIG. 10 shows a central portion of the suspension device according to the modified example.

The first feature of this modification is that the magnet 3
A through hole is provided between the magnets 36 and 37 of the supporting member 35 supporting the inner and outer peripheral surfaces of the coil assembly and facing the inner peripheral surface of the coil assembly. In this case, the support member 35 is connected to the sleeve member 35a.
And the ring member 35b, and through holes 35a1 and 35b1 are formed at appropriate plural locations in the circumferential direction of the two members 35a and 35b.
Are provided so as to be continuous. Another feature of this modified example is that a plurality of check valves 71 are provided on the inner peripheral surface of the lower case 24 while a plurality of check holes 71 are provided on the inner peripheral surface of the lower case 24. That is. The check valve 71 is provided at a position corresponding to the through hole 34a, and prohibits the passage of air from the inner peripheral surface side of the lower case 34 to the outer peripheral surface through the through hole 34a. Only the passage of air from the airbag to the inner peripheral surface side through the through hole 34a is permitted.

In this modification, the through holes 35a1, 35a1
35b1, the air chamber R flowing from the upper case 23 to the connection case 25 when the vehicle body BD is displaced downward (when the damper device is in a contracted state).
The air in 4 is applied to the coating layer 44 of the coil assembly.
Flows through the through holes 35a1 and 35b1 as well as on the inner peripheral surface of. Then, when the coating layers 44 and 45 or the coating layers 44 and 46 are stuck due to a shift between the axis of the coil assembly and the axes of the lower case 24 and the support member 35 (in the case of sticking).
In this case, the air that has passed through the through holes 35a1 and 35b1 enters between the outer peripheral surfaces of the magnets 36 and 37 and the coating layer 44, so that the flowed air is automatically released from the state of being stuck. Further, since the through hole 34a and the check valve 71 are provided, when the vehicle body BD is displaced upward (when the damper device is in an extended state), the air chamber R4 flowing from the inside of the connection case 25 to the inside of the upper case 23 is provided. The air mainly flows through the through hole 34a and the check valve 71. In this case, if the through hole 34a is made large to some extent, the air passing through the through hole 34a does not prevent the vehicle body BD from displacing upward, and the vehicle body BD displaces upward without resistance.

In the above embodiment and its modifications, the coil assembly is fixed to the upper case 23 via the rubber sheet 48 and the magnets 36 and 37 are fixed to the support member 35 fixed to the lower case 24. However, the magnets 36 and 37 may be fixed to the upper case 23 side, and the coil assembly may be fixed to the support member 35 fixed to the lower case 24 or the lower case 24.

[Brief description of the drawings]

FIG. 1 is a partially cutaway view showing an entire suspension device according to an embodiment of the present invention.

FIG. 2 is an enlarged view of a central portion of the suspension device of FIG.

FIG. 3 is an overall block diagram of an electric control device that controls the suspension device of FIG. 1;

FIG. 4 is a schematic diagram showing the coils of FIGS. 1 to 3 and a driving circuit of the coils.

FIG. 5 is a flowchart of a damping force switching program executed by the microcomputer of FIG. 3;

FIG. 6 shows a vehicle speed V and a lateral acceleration Gy in a V-Gy map.
6 is a graph showing the relationship of.

FIG. 7 is a flowchart of a coil energization / de-energization control program executed by the microcomputer of FIG. 3;

FIG. 8 is an explanatory diagram for explaining a relationship between a vehicle height HT and an energizing coil in an energization map.

FIG. 9 is a time chart showing a coil energization control state and a damping force switching control state with respect to changes in a steering wheel steering angle, a steering angular velocity, and a lateral acceleration (constant vehicle speed).

FIG. 10 is a cross-sectional view showing a modified example of a central portion of the suspension device of FIG.

[Description of Signs] 11 ... Outer cylinder, 12 ... Inner cylinder, 13 ...
Piston rod, 17: Main piston, 18: Sub piston, 21: Actuator, 23: Upper case, 2
4 lower case, 25 connecting case, 36, 37 magnet, 41 casing, 42 coil, 44, 45, 4
6: coating layer, 48: rubber sheet, 55: microcomputer.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yasunobu Isoko 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (4)

[Claims] A cylinder filled with hydraulic fluid and a piston rod protruding from an upper end surface of the cylinder so as to advance and retreat, a lower end of the cylinder being assembled to a unsprung member, and an upper end of the piston rod being a sprung member. A damper device that generates a damping force by the vertical movement of the sprung member with respect to the unsprung member; and a damper device provided on the outer peripheral surface of the cylinder and the piston rod, and a lower end supported by the outer peripheral surface of the cylinder. And air having an upper end supported by the sprung member and having flexibility, and applying a spring action to the vertical movement of the sprung member with respect to the unsprung member by the gas sealed in the case. A suspension device for a vehicle including a spring device, wherein the suspension device is disposed inside the case and outside the cylinder so as to face each other. Suspension device for a vehicle, characterized in that a said cylinder and said piston rod and each magnet and the coil which is displaced integrally. 2. An upper case having a cylindrical shape and an upper end fixed to an outer peripheral surface of a piston rod and elastically supported by the sprung member, and a cylindrically formed lower end. A lower case in which a portion is fixed to the outer peripheral surface of the cylinder, and a connection case configured in a sheet shape with a material that is easily deformed and connecting the upper case and the lower case, and one of the magnet and the coil is provided. And fixing the other of the magnet and the coil to the lower case.
A vehicle suspension device according to claim 1. 3. An apparatus according to claim 2, wherein an upper portion of said lower case is supported on an outer peripheral surface of said cylinder.
A vehicle suspension device according to claim 1. 4. An upper case having a cylindrical shape and an upper surface supported by the sprung member, a lower case having a cylindrical shape and having a lower end fixed to an outer peripheral surface of the cylinder. The upper case and the lower case are connected in a sheet shape with a material that is easily deformed. The lower case is provided with a cylindrical support member at an upper end of the lower case separately from the cylinder. One of the magnet and the coil is fixed to the inner peripheral surface of the upper case, and the other of the magnet and the coil is fixed to the outer peripheral surface of the support member, and the support member has a radial through hole. The vehicle suspension device according to claim 1, wherein the suspension device is provided so as to be opened on the opposing surfaces of the magnet and the coil.