JPH0861418A - Method and equipment for absorbing mechanical shock - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an apparatus and a method capable of simultaneously damping motion of an automobile body and motion of a wheel and an axle of a vehicle by absorbing a mechanical shock. SOLUTION: A pressure cylinder 40 forms a working chamber having first and second portions capable of housing a damping fluid. An apparatus has a first valve for controlling a flow of the damping fluid between the first and second portions of the working chamber during compression of a shock absorber, and also has pressure chambers 90, 94 in fluid communication with the first portion of the working chamber and a first valve. A solenoid is also provided for regulating the flow of the damping fluid between the pressure chambers and the second portion of the working chamber. A second valve is further provided for controlling the flow of the damping fluid between the first and second portions of the working chamber during rebound of the shock absorber.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to suspension systems for motor vehicles, and more particularly to a method and apparatus for absorbing mechanical shock.

[0002]

Shock absorbers are used in combination with vehicle suspensions to absorb unwanted vibrations that occur during driving. To absorb the unwanted vibrations, shock absorbers are generally connected between the body of the vehicle (vehicle body) and the suspension. A piston is located in the shock absorber and is connected to the vehicle body via a piston rod. The piston rod can restrict the flow of damping fluid in the working chamber of the shock absorber when the shock absorber is compressed, so that the shock absorber can generate a damping force, The force dampens vibrations that would otherwise be transmitted from the suspension to the body. The more restricted the flow of damping fluid in the working chamber is by the piston, the greater the damping force produced by the shock absorber.

When selecting the magnitude of the damping force to be provided by the shock absorber, three performance characteristics of the vehicle, that is, the riding comfort, the operability of the vehicle, and the road holding force (road holding ability) are taken into consideration. I often do it.
Ride comfort is often a function of the spring constant of the vehicle's main spring and the spring constants of seats, tires, and shock absorbers. Vehicle maneuverability is related to variations in vehicle behavior (ie, roll, pitch and yaw). For optimum vehicle maneuverability, a relatively large damping force is required to prevent the vehicle behavior from changing too rapidly during cornering, acceleration and deceleration.

In general, road holding force is a function of the degree of contact between the tire and the ground. In order to optimize the load holding force, increase the damping force when driving an irregular surface (rough surface), resulting in contact loss between the wheel and the ground for an excessively long time Need to be prevented.

Generally, in order to optimize ride comfort, vehicle maneuverability and road holding force, it is necessary that the damping force generated by the shock absorber be able to respond to the input frequency from the road. There is. When the input frequency from the road is equal to the natural frequency of the vehicle body (eg, approximately 0-2 Hz), the shock absorber provides a large damping force, which causes excessive vehicle behavior during cornering, acceleration and deceleration. It is generally desirable to prevent rapid fluctuations. When the input frequency from the road is 2-10 Hz, the shock absorber provides a small damping force to provide a smooth riding comfort and allows the wheel to follow changes in the undulations of the road. Generally desirable. When the input frequency from the road is approximately equal to the natural frequency of the suspension of the automobile (that is, about 10-15 Hz), the damping force is made relatively small to provide a smooth riding comfort and at the same time, the wheel and the ground. It is desirable to provide a sufficiently large damping force to prevent excessive contact loss between and.

One method for selectively changing the damping characteristics of a shock absorber is US Pat. No. 4,59.
No. 7,411. In this U.S. patent, a solenoid is used to selectively open and close an auxiliary opening in the shock absorber base valve. Thereby, the base valve regulates the pressure in some part of the working chamber of the shock absorber to control the damping action. Another method for selectively changing the damping characteristics of a shock absorber is disclosed in one PCT application. This PCT application, in one embodiment, includes a pressure sensor that counts the number of absorber compression / rebound cycles and an acceleration mounted on a wheel support to determine the vertical velocity of the vehicle body. I am using a meter. As a result, the damping characteristic of the absorber changes according to the speed of the body in the vertical direction.

Another method for selectively changing the damping characteristics of a shock absorber is described in British Patent 2,147,
No. 683 (GB2,147,683A). This British patent, in one embodiment thereof, discloses a valve disc for covering a groove in a valve body that carries damping fluid between an upper portion and a lower portion of a working chamber. used. The valve disc is biased towards the valve body by a support member, a portion of which is located in the pressure chamber. The pressure chamber communicates with the lower part of the working chamber via a first flow path and with the upper part of the working chamber via a second flow path.
An auxiliary valve plate is provided to regulate the flow rate of damping fluid through the second flow path, and thus the pressure in the pressure chamber acting on the support member. The auxiliary valve plate is provided above the second channel and cooperates with a coil provided on the valve body below a portion of the auxiliary valve plate. When the coil is energized, the magnetic flux generated by the coil exerts a biasing force on the auxiliary valve disc, which causes the auxiliary valve disc to flex and thus the second valve disc. The opening between the flow path and the upper part of the working chamber is increased. Therefore, when the coil is mounted on the auxiliary valve disk at a position where the coil biases the auxiliary valve disk and allows a larger amount of working fluid to flow through the second flow path, the pressure is increased. The pressure of the damping fluid in the chamber is reduced, which reduces the force transmitted by the support member to the valve plate. The pressure in the lower portion of the working chamber causes the valve plate to flex, thereby increasing the amount of damping fluid flowing through the groove.

[0008]

SUMMARY OF THE INVENTION Accordingly, the basic object of the present invention is to absorb mechanical shocks, motions of a vehicle body, and wheels and axles (axles of a vehicle) of a vehicle. The method and apparatus are capable of simultaneously dampening the movements of 1).

Another object of the present invention is to absorb a mechanical shock and to make a turn (operation to change the direction of a vehicle), acceleration, or
It is an object of the invention to provide a method and a device by which the tendency of a motor vehicle to roll, pitch or yaw during braking can be mitigated.

Yet another object of the present invention is to absorb mechanical shocks and provide an acceptable level of friction between the road surface and the tires of the vehicle, thereby maintaining the braking and decelerating ability of the vehicle. Is to provide a method and an apparatus capable of doing so.

Another object of the invention is to provide a method and a device capable of absorbing mechanical shocks and producing adjustable damping characteristics for the motor vehicle body in response to different driving environments and different driving habits. Is to provide.

Yet another object of the present invention is to provide a new and improved direct actuated hydraulic shock absorber having high flexibility for mounting on various types of vehicles. . The object of the invention in this context is to provide a device for absorbing mechanical shocks, which is relatively inexpensive and relatively easy to maintain.

A more particular object of the present invention is to use a solenoid to control the flow of damping fluid through the various passages of the device under various operating conditions, thereby controlling the damping force provided by the device. It is to provide a new and improved shock absorber having the above characteristics.

Yet another object of the present invention is to provide a shock absorber as described above, wherein the damping force is controlled by a computer capable of responding to the differential pressure between the two parts of the working chamber of the device. Is.

Another object of the present invention is to provide a method and apparatus for absorbing mechanical shock in which the damping force is controlled by a computer capable of responding to vertical movements of the vehicle body. That is.

Yet another object of the present invention is to absorb mechanical shock, the damping force of which is controlled by a computer which can be reprogrammed so that the device can provide various damping characteristics. Method and apparatus.

Various advantages of the present invention will be appreciated by those of ordinary skill in the art upon reading the following description in conjunction with the drawings.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a plurality (four) of shock absorbers 20 according to a preferred embodiment of the present invention is shown. These shock absorbers 20
Are shown operatively associated with a conventional vehicle 22 shown schematically. The motor vehicle 22 includes a rear suspension 24 having a laterally extending rear axle assembly 26 adapted to operatively support a rear wheel 28 of a vehicle. The axle assembly 26 includes a pair of shock absorbers 20 and a spiral coil spring 30.
Is operatively connected to the vehicle 22. Similarly, the vehicle 22 includes a front suspension device 32, which includes a front axle assembly 34 extending laterally and operatively supporting a front wheel 36. The front axle assembly 34 has a second
The pair of shock absorbers 20 and the spiral coil spring 38 are operatively connected to the automobile 22. The shock absorber 20 includes an unsprung portion of the vehicle 22 (that is, the front suspension 32).
And the rear suspension 24) and the spraging portion (i.e., the body 39). Although automobile 22 is shown as a passenger vehicle, shock absorber 20 may be used with other types of automated vehicles.

With particular reference to FIG. 2, a shock absorber 20 of the preferred embodiment of the present invention is shown. The shock absorber 20 includes an elongated tubular pressure cylinder 40.
And the pressure cylinder defines a working chamber 42 containing a damping fluid. Provided within the working chamber 42 is a reciprocable piston 44, which is fixed to one end of an axially extending piston rod 46. The piston 44 has a circumferential groove 48 that can accommodate a piston ring 50, as is well known in the art. Piston ring 50 is used to prevent dampening fluid from flowing between the outer circumference of piston 44 and the inner circumference of cylinder 40 during movement of piston 44. A base valve, generally designated by the reference numeral 52, is located in the lower end of the pressure cylinder 40, said base valve comprising a working chamber 42 and an annular fluid reservoir 54.
It is used to control the flow of damping fluid between and. The annular fluid reservoir 54 is formed as a space between the outer periphery of the cylinder 40 and the reservoir tube, that is, the cylinders 56 arranged concentrically around the outside of the pressure cylinder 40. The structure and operation of base valve 52 is described in US Pat.
71,626 and can be of the type illustrated and described.

A substantially cup-shaped upper end cap 58 and a lower end cap 60 are provided at the upper end and the lower end of the shock absorber 20, respectively. The end caps 58 and 60 are fixed to both ends of the reservoir tube 56 by a suitable means such as welding. The shock absorber 20 is shown provided with a dirt shield (dirt shield) 62, the upper end of which is fixed to the upper end of the piston rod 46. Suitable end fittings (end fittings) 64 are secured to the upper end of the piston rod 46 and the lower end cap 60,
Between the body of the car 22 and the axle assembly,
It serves to fix the shock absorber 20. Those skilled in the art will recognize that as the piston 44 reciprocates, the damping fluid in the pressure cylinder 40 will move between the piston portions above and below the working chamber 42, as well as the working chamber 4.
It can be seen that it is carried between the two and the fluid reservoir 54. By controlling the flow of dampening fluid between the upper and lower portions of the working chamber 42, the shock absorber 20 controllably dampens relative movement between the vehicle body 22 and the suspension.
This makes it possible to optimize ride comfort and road handling. To this end, the piston 44 is provided with a new and improved valve structure (valve switching mechanism) which, during a reciprocating movement of the piston, will be described in more detail below. , Selectively control the flow of damping fluid between the upper and lower portions of the working chamber 42.

According to a first preferred embodiment of the invention,
The piston 44 includes a valve body (valve body) 66, and the valve body includes a first and second plurality (2).
(3) flow passages 68 and 70. Flow paths 68, 7
0 is the upper surface 72 of the valve body 66 and the valve body 66.
Between the lower surface 74 and the lower surface 74. Each flow passage 68
Has a valve controlled upper outlet end 76 and a counterbore lower inlet end 78. Similarly, each flow passage 70 has a valve-controlled lower outlet end 80 and a counterbore upper inlet end 82.

Two valve disks 84, 86 are provided to provide a means for controlling the flow of damping fluid between the upper and lower portions of the working chamber 42. The valve discs 84 and 86 have a valve body 66.
Are arranged concentrically adjacent to the upper surface 72 and the lower surface 74, respectively. The valve disc 84 has a flow passage 68.
Has a diameter sufficient to align with and cover the outlet end 76 of the device so that damping fluid is prevented from entering the outlet end 76. However, the valve disc 84
It does not cover the counterbore inlet end 82 of the flow passage 70, which allows damping fluid to enter the counterbore inlet end 82. The valve disc 84 also cooperates with a recess 88 in the upper surface 72 of the valve body 66 to form a first pressure chamber 90. In this regard, the valve disc 86 has a diameter that is aligned with and covers the outlet end 80 of the flow passage 70, but not the counterbore inlet end 78. Further, the valve disc 86 is
A second pressure chamber 94 is formed in cooperation with the second recess 92 of the lower surface 74 of the valve body 66.

To support the valve body 66 in the pressure cylinder 40, the valve body 66 has a central bore 96 capable of receiving an axially extending piston post 98. The piston post 98 has an upper portion 100 which is adapted to threadably engage an externally threaded lower end 104 of the piston rod 46 with an internally threaded central bore 102. have. Two flow passages 105 extending in the radial direction are provided in the piston post 98.
From the pressure chamber 94 of the valve body 66 to the central hole 9
It communicates with two flow passages 106 extending in the radial direction up to 6. The flow passages 105, 106 allow damping fluid to flow between the pressure chamber 94 and a solenoid, which is described below. The piston post 98 also has a radially extending step 107 which includes the central bore 9.
It has an outer diameter greater than the diameter of 6. Step 107
Is provided above the valve body 66, the step portion 107 includes the valve body 66 and the piston post 98.
Restricts upward movement relative to. Further, a piston holding nut 108 is provided, and this piston holding nut has an internally threaded hole 109, which is located below the valve body 66 and has a piston post 98. Lower part 1 with external thread
10 and 10 in a screw type engagement. The outer diameter of the piston retaining nut 108 is larger than the diameter of the central hole 96 of the valve body 66, so the nut 108 prevents the valve body 66 from moving downward relative to the piston post 98. . The piston post 98 and piston retaining nut 108 also serve to secure the innermost portions of the valve discs 84, 86. In this regard, the innermost portion of the valve disc 84 includes the radially extending step 107 of the piston post 98 and the upper surface 7 of the valve body 66.
Engage both of the two. Further, the radially innermost portion of the valve disc 86 engages with the lower surface 74 of the valve body 66 and the piston holding nut 108.

To bias the valve discs 84, 86 toward the surfaces 72, 74 of the valve body 66, a pair of coaxially coiled axially spaced helical springs 112, 114 are provided. Has been. Spring 112
Between the step portion 116 formed on the piston post 98 and extending in the radial direction and the intermediate receiving plate 118 adjacent to the upper surface of the valve disc 84 and coaxially arranged with the upper surface of the valve disc 84. They are arranged coaxially. The intermediate backing plate 118 allows the spring 112 to elastically and yieldably bias the valve disc 84 toward the upper surface 72 of the valve body 66. Similarly,
The spring 114 is provided between the radially extending flange 120 of the piston retaining nut 108 and an intermediate backing plate 122 adjacent the valve disc 86 and coaxially therewith. Therefore, the spring 114
The valve disc 86 can be elastically and yieldably biased toward the lower surface of the valve body 66 via the intermediate receiving plate 122.

In accordance with the principles of the present invention, piston 44 further provides an electrically controllable flow means for controlling actuation of valve discs 84, 86.
A solenoid 124 is provided. Solenoid 124
The piston post 98 includes a housing 126 coaxially arranged in a central hole 128 of the piston post 98. Within the housing 126 is a coil 130 and an armature 132 having an enlarged counterbore 134. Armature 132 is counterbore 1
A helical coil spring 136 provided in the shaft 34 biases the valve body 66 axially upward relative to the valve body 66. The upper end of spring 136 presses against radial surface 138 of counterbore 134, while the lower end of spring 136 presses against the upper side of seal plate 140. An O-ring or similar type sealing element 142 provides a coil 130 and armature 132.
Is provided between the coil and the armature to prevent the damping fluid from flowing between the coil and the armature. Ring 1
Reference numeral 44 is provided between the coil 130 and the seal plate 140 to ensure that the spatial distance between the coil 130 and the seal plate 140 is kept constant.

The solenoid 124 is also an annular ring 1.
Also provided is 46, which is an annular ring made of a ferromagnetic material provided between the armature 132 and the housing 126 and adjacent to the coil 130. The annular ring 146 is used to complete the magnetic flux path generated by the coil 130 and to ensure proper operation of the solenoid 124. The solenoid 124 also includes an annular housing cap 148 that is horizontally aligned with the upper portion 150 of the housing 126. The housing cap 148 has a centrally arranged axial flow passage 152 that allows damping fluid in the housing 126 to flow to one surface of a pressure sensor, which will be described below. Tolerate. Solenoid 12
An externally threaded solenoid retention plug 153 is provided to secure the 4 in the piston post 98.
The solenoid retention plug 153 engages the internally threaded lower portion 110 of the piston post 98. Plug 153
Has an axially extending central bore 154 that allows damping fluid to flow between the seal plate 140 and the lower portion of the working chamber 42.

The solenoid 124 is a seal plate 14
Working in cooperation with 0 to control the flow of damping fluid between the central flow passage 155 and a plurality of radially displaced flow passages 156 provided in the seal plate 140.
When the solenoid 124 is not energized, the damping fluid flows through the central passage 155 and the radially displaced passage 1.
It can flow to and from 56. When the solenoid 124 is energized, the armature 132 will
The seal plate 14 is moved downward against the force of 36.
It reaches the position where it is sealingly engaged with 0. When this occurs, armature 132 blocks the flow of fluid between passageways 155 and 156. An O-ring or similar sealing element 158 is provided on the armature 132,
The O-ring or similar sealing element is a solenoid 12
4 blocks the flow of dampening fluid between the armature 132 and the seal plate 140 when activated.

The valve body 66 further includes the flow passage 1 to allow fluid flowing through the passages 155, 156 to bias the valve discs 84, 86 in opposite directions.
60 and 162 are provided. The flow passage 160 extends axially from the pressure chamber 90 to the pressure chamber 94, while the flow passage 162 extends radially from the flow passage 70 to the pressure chamber 94. The damping fluid in the pressure chamber 94 can flow through the flow passage 10 of the valve body 66.
6 and the flow passage 105 of the piston post 98 allows the flow to the flow passage 156 which is displaced in the radial direction of the seal plate 140.
Two flow paths are formed in 6. The first flow path allows damping fluid to flow from an upper portion of the working chamber 42 to a lower portion of the working chamber 42. In this regard, the first flow path allows the damping fluid in the upper portion of the working chamber 42 to flow through the flow passage 162 to the pressure chamber 94. Therefore, the damping fluid in the pressure chamber 94 can flow through the flow passage 105 of the piston post 98 and the flow passage 106 of the valve body 66 to the radially displaced flow passage 156 of the seal plate 140. it can. Solenoid 124
The damping fluid flowing through the radially displaced passages 156 when the
Flow through the central flow passage 155 of 40 and the central hole 154 of the solenoid retention plug 153 into the lower portion of the working chamber 42.

The second flow path allows damping fluid to flow between the lower portion of the working chamber 42 and the pressure chamber 90. In this regard, the second flow path is such that the damping fluid in the lower portion of the working chamber 42 passes through the central hole 154 of the solenoid retention plug 153 and the seal plate 1
Allowing flow to 40 central flow passages 155. If the solenoid 124 is not energized, the central hole 15
The damping fluid that flows through the flow path 4 of FIG.
8, the flow passage 105 and the flow passage 1 of the valve body 66.
Flow through 06 to the pressure chamber 94. The damping fluid can then flow from the pressure chamber 94 via the flow passage 160 to the pressure chamber 90.

An annular retaining seal 164 is provided to prevent leakage of damping fluid into the pressure chamber 90. An annular retaining seal 164 is provided on the valve disc 84.
Adjacent to the pressure chamber 90,
This prevents damping fluid in the pressure chamber 90 from entering the upper portion of the working chamber 42. An annular retaining ring 168 is also provided in the pressure chamber 90 adjacent the annular retaining seal 164, which causes the seal 164 to be displaced to allow the pressure chamber 90 and the upper portion of the working chamber 42 to be displaced. It is designed to prevent fluid leakage between them. In a similar manner, an annular retaining seal 170 is provided adjacent the valve disc 86 and adjacent to the chamber 9
It is provided in 4. The annular retaining seal 170
The damping fluid in the pressure chamber 94 is transferred to the working chamber 42.
Used to prevent entry into the lower part of the. The annular retaining ring 172 also has an annular retaining seal 16
4 is located in the pressure chamber 94, adjacent to No. 4, thereby displacing the seal 170 so that damping fluid does not leak between the pressure chamber 94 and the lower portion of the working chamber 42. I am trying.

When the shock absorber 20 of the present invention operates, as shown in FIGS. 6 to 9, the armature 1
The position of 32 depends on whether the shock absorber 20 is compressing or rebounding or returning, and further, whether a hard or soft stroke is desired. If a soft compression stroke is desired, the solenoid 124 remains idle (idle), as shown in FIG. 6, which causes the damping fluid in the lower portion of the working chamber 42 to Central hole 1 of solenoid holding plug 153
54 and the flow passages 155, 1 of the seal plate 140
Flow through 56 to flow passage 105 of piston post 98. The damping fluid may then flow from the flow passage 105 of the piston post 98, through the flow passage 106 of the valve body 66, the pressure chamber 94, and the flow passage 160 to the pressure chamber 90. The flow of damping fluid to the pressure chamber 90 causes the pressure in the pressure chamber 90 to exceed the pressure in the upper portion of the working chamber 42, creating a pressure differential across the valve disc 84. This differential pressure is applied to the valve disc 8
4 is biased in the opposite direction, allowing more damping fluid to flow through the flow passage 68 than would otherwise be acceptable. Allowing more damping fluid to flow through the flow passage 68 creates a softer compression stroke. If a tight compression stroke is desired, solenoid 124 is actuated as shown in FIG. 8 to allow damping fluid to flow from central passage 155 to radially displaced passage 156 of seal plate 140. Block. This prevents damping fluid in the lower portion of working chamber 42 from entering pressure chamber 90 so that the pressure in pressure chamber 90 is substantially the same as the pressure in the upper portion of working chamber 42. Is the same as The damping fluid in the pressure chamber 90 creates no differential pressure across the valve disc 84, so the valve disc 84 is removed except for the reverse biasing force produced by the damping fluid flowing through the flow passage 68. The reverse biasing force does not act at all. Therefore, the valve disc 84 allows a small amount of fluid to flow through the flow passage 68.
Flushing, which results in a tight compression stroke.

If a tight rebound stroke is desired, the solenoid 124 is not energized, as shown in FIG. 7, which causes the spring 136 to bias the armature 132 to its raised position. Therefore, the valve body 6
Damping fluid from the upper portion of the working chamber 42 that flows through the flow passages 70, 162 of the six into the pressure chamber 94, via the flow passage 105 of the piston post 98 and the flow passage 106 of the valve body 66, is radiated. It can flow to the flow passage 156 which is displaced in the direction. Armature 1
As 32 is biased upwards, the damping fluid flowing into the radially displaced passage 156 is
0 central flow passage 155 and solenoid retention plug 1
Flow through the central hole 154 of 53 to the lower part of the working chamber 42. Therefore, the pressure chamber 9
Since the pressure in 4 is substantially the same as the pressure in the lower portion of working chamber 42, the damping fluid in pressure chamber 94 does not create any differential pressure across valve disc 86. . Therefore, the only reverse biasing force acting on the valve disc 86 is the biasing force provided by the damping fluid flowing through the flow passage 70. The reverse biasing force acting on the valve disc 86 causes the solenoid 1
Since less than the biasing force that would occur if 24 were excited, there would be less fluid flowing through passage 70,
This results in a tight rebound stroke. If a soft rebound stroke is desired, the solenoid is energized, as shown in FIG. 9, causing damping fluid to flow between the central flow passage 155 and the radially displaced flow passage 156. Block. Therefore, damping fluid from the upper portion of the working chamber 42, through the flow passages 70, 162 and entering the pressure chamber 94, remains in the pressure chamber 94. Therefore, the pressure in pressure chamber 94 is greater than the pressure in the lower portion of working chamber 42. Since a differential pressure is developed across the valve disc 86, the resulting reverse biasing force on the valve disc 86 allows a large amount of damping fluid to flow through the passage 70, Causes a soft rebound stroke.

In accordance with the principles of the present invention, shock absorber 20 further includes a pressure sensor 180, which detects the differential pressure between the damping fluid in the upper and lower portions of working chamber 42. Provide a means to make a decision. The pressure sensor 180 is mounted on an annular member 182, which is formed between the piston rod 46 and the central bore 128 of the piston post 98 and between the radially inwardly extending step portion 184. And is provided in the piston post 98. The annular member 182 has a passage 186 that extends in the radial direction and an axial passage 188 that partially penetrates the annular member 182. The radially extending passage 186 communicates with the axial passage 188 at the radially inward end of the radially extending passage 186. The radially extending passage 186 also communicates at its radially outer end with a passage 190 formed in the piston post 98. The pressure sensor 180 overlies the axial passageway 188 so that damping fluid from the upper portion of the working chamber 42 will pass through the passageway 188.
0, 186 through the first surface 1 of the pressure sensor 180
It can flow up to 92. Also, the working chamber 42
The damping fluid in the lower part of the
53 central hole 154, seal plate 140 central flow passage 155, armature 132 counterbore 13
4 and through the flow passage 152 of the housing cap 148 to the second surface 194 of the pressure sensor 180. With the structure described above, the pressure sensor 18
0 first and second surfaces 192, 194 are in fluid communication with the damping fluid in the first and second portions of the working chamber 42. Therefore, the pressure sensor 180 is
A signal representative of the differential pressure between the damping fluid in the upper and lower portions of the can be generated.

An accelerometer 196 located on the annular member 182 is provided to provide a means for determining the motion of the body of the vehicle 22. Accelerometer 196
Since it is fixed to the annular member 182, this accelerometer 1
The 96 can move integrally with the piston rod 46 and thus the body of the vehicle 22. Therefore, the accelerometer 1
The 96 can generate an electric signal according to the vertical acceleration of the body of the automobile 22. By performing numerical integration on the output from the accelerometer 196, the vehicle 2
The vertical velocity of the two bodies can be determined.

Shock absorber 20 further includes a piston post 98 to provide a means for generating an electrical control signal for energizing solenoid 124 in response to the outputs from pressure sensor 180 and accelerometer 196. A signal conditioning circuit is provided therein, generally designated by the reference numeral 198. A plurality of first conducting wires 20
0 extends through the annular member 182 and the signal conditioning circuit 1
The electrical connection between 98, the pressure sensor 180 and the accelerometer 196 is allowed. As shown in FIG. 10, the signal conditioning circuit 198 includes a pressure sensor 180 and an accelerometer 196.
The output from the amplifier is amplified before being provided to a computer, generally designated by the reference numeral 202. Computer 2
02 is responsive to an electrical signal from the output of the signal conditioning circuit 198 and is one of several stored programs described below.
According to one, it is used to generate the A and B outputs. The computer 202 produces a logically high or low A output when the compression stroke is to be softened or stiff, respectively. Similarly, computer 202 produces an electrically high or an electrically low B output, respectively, when the rebound stroke should be softened or stiffened. The A and B outputs of computer 202 are then provided to solenoids via a solenoid drive circuit, generally designated by the reference numeral 204. Solenoid drive circuit 20
4 is used to convert the output of computer 202, as well as the output of signal conditioning circuit 198, into voltage levels that can be used to activate solenoid 124. The plurality of second conductors 206 are connected to the computer 2
02 and the output of the signal adjusting circuit 198 are connected to the annular member 182.
It is used to supply the solenoid drive circuit 204 via the.

As shown in FIG. 11, the drive circuit 204 includes
It comprises a signal conditioning circuit 198 and a comparator 208 for receiving an output signal from an adjustable voltage source, said adjustable voltage source being indicated by a variable resistor 210. The output from the signal conditioning circuit 198, which is provided to the drive circuit 204, is a voltage that is a function of the differential pressure between the upper and lower portions of the working chamber 42. When the pressure in the lower portion of the working chamber 42 exceeds the pressure in the upper portion of the working chamber by a predetermined level (ie, during rebound), a voltage above the voltage provided by the variable resistor 210 is exceeded. , On the output side of the signal conditioning circuit 198. In such a condition, a logically high output will occur at the output of comparator 208. If the pressure in the lower portion of the working chamber 42 is lower than the pressure in the upper portion of the working chamber 42, the voltage provided by the signal conditioning circuit 198 is the variable resistor 21.
Less than the voltage supplied by zero. Under such a condition, a logically low voltage is generated at the output side of the comparator 208.

In order to ensure that the voltages applied to the various logic gates described below have the appropriate magnitude, the output of comparator 208 is connected through resistor 212 to
It is supplied to the inverter 214 and further supplied to the ground via the resistor 216. The resistors 212 and 216 are
The voltage supplied to the inverter 214 serves to ensure that the voltage is within a certain range, and the certain range is
The inverter 214 is provided with a drive circuit 204 described later.
The range is such that a response output that matches other elements of is generated. The output of the comparator 208 is also the capacitor 218.
Is connected to the capacitor and serves to filter the relatively high frequency noise present at the output of the comparator 208. The output from the inverter 214 is connected to the NOR gate 220 and the AND gate 222.
NOR gate 220 and AND gate 22 also receive the A and B outputs of computer 202. The A output and the B output are also supplied to the XOR gate 224, and the A output and the output from the XOR gate 224 are
It is supplied to the AND gate 226. Gates 220 and 22
The outputs from 2 and 226 are connected to OR gate 228 so that the output from OR gate 228 responds according to Table 1 below.

[0038]

[Table 1] Thus, when both the A and B outputs from computer 202 are low, solenoid drive circuit 204 causes solenoid 124 to respond directly to the output from pressure sensor 180. Similarly, if both the A and B outputs are high, the drive circuit 204 causes the solenoid 124 to follow the inverted output from the pressure sensor 180. When only the B output is high, the drive circuit 204 excites the solenoid 124, while when only the A output is high,
The solenoid 124 remains unenergized.

The output from OR gate 228 is provided to input pin 1 of excitation controller 230. The excitation controller 230 is used to control the base current supplied to the external power supply type NPN Darlington transistor 234 that excites the solenoid 124. Excitation controller 230 is initially configured such that transistor 234 provides a sufficiently large current so that armature 1
Allowing 32 to engage seal plate 140. After the armature 132 engages the seal plate 140, the excitation controller 230 causes the solenoid 1
The current supplied to 24 is reduced to a level that maintains the position of armature 132 relative to seal plate 140. To energize the controller 230, the supply pin 7 of the controller 230 is connected to a supply bus V _CC carrying a nominal potential of 5 volts. The timer pin 8 of the controller 230 is also connected to the supply bus V _CC via a resistor 236 and the capacitor 23
It is connected to the ground via 8. The values of resistor 236 and capacitor 238 determine the time after which solenoid 124 is first activated to reduce the current through solenoid 124.

The output pin 2 of the controller 230 is connected to the base of the transistor 234 and one plate of the capacitor 240. The second plate of the capacitor 240 is connected to computer pin 3 of the controller 230, which causes the capacitor 240 to
Stability can be provided to the circuit when the solenoid 124 is held in its activated state. The sensing input pin 4 of these 230 is connected to the emitter of the transistor 234 via a resistor 242, and
It is connected to ground via a resistor 244. The resistors 242, 244 serve to establish the minimum current required to hold the solenoid 124 in its actuated state. Diode 246 is also connected between the emitter of transistor 234 and ground to ensure that the voltage at the emitter of transistor 234 is equal to the forward bias voltage of diode 246 (about 0.7 volts). Inductive kickback of transistor 234 when the current to solenoid 124 is reduced.
A Zener diode 248 is provided for protection from the above. Zener diode 248 provides a path for current from solenoid 124 when the voltage across diode 248 exceeds the breakdown potential of diode 248 (about 35 volts). Therefore,
Diode 248 limits the voltage supplied to the collector of transistor 234 to 35 volts, thereby reducing the effect of inductive kickback on transistor 234.

Using the information provided by accelerometer 196 and pressure sensor 180, the motion of the body of the vehicle can be damped by the procedure shown in FIG. Initially,
The compression stroke and rebound stroke are soft, as shown in step 250, and during the compression stroke the solenoid 124 is held inactive.
It is meant to be activated during the rebound stroke. In step 252, the output from accelerometer 196 is read by computer 202 and added to the previous acceleration reading in step 254 to obtain the vertical velocity V _body of the vehicle 22 body. To be The computer 202 determines in step 256 whether the velocity value obtained from the accelerometer 196 is greater than a predetermined value V _O, which can typically be 0.05 m / s. If the vertical velocity V _body is less than the predetermined value _VO ', the solenoid 124 is held in its inoperative state during compression, as shown in step 258, and during rebound. Is held in its operating state. If the value of the vertical speed of the body of the vehicle 22 is greater than the predetermined value VO ', the computer 202 determines in step 260 whether the body of the vehicle 22 is moving up or down with respect to the road. To determine if it is moving to. As shown in step 262, the vertical velocity V _body is
Solenoid 1 if positive and indicating upward movement
24 is held inoperative during both the compression stroke and the rebound stroke to produce a hard rebound stroke and a soft compression stroke. If the vertical velocity V _body is negative, the computer 202 activates the solenoid 124 during both the compression stroke and the rebound stroke, as shown in step 264. Solenoid 1
After the 24 responses have been determined according to steps 250-264, the process returns to step 250 via step 266, or, alternatively,
Return to other initial steps. By using the above method, shock absorber 20 can provide maximum damping force when the frequency of vertical motion of the body of vehicle 22 is substantially equal to 1.5 Hz.

In order to minimize the vibration of the body of the automobile 22 caused by the natural frequencies of the wheels 28 and 36, the computer 124 can be used to control the solenoid 124 in the procedure shown in FIG. First, the differential pressure between the upper and lower parts of the working chamber 42 is
Read in step 268. Step 270
, The natural frequency of the wheel (typically 10-1
A series of pressure values is obtained during a time interval approximately equal to 5 Hz). Next, in step 272, the value A ² is determined according to the following equation 1 using the value of the differential pressure.

[0043]

(Equation 1) In step 274, the value of A ² is compared to the value of A _O ^2. A _O ² represents a constant preselected to allow the shock absorber to stiffen when the piston speed exceeds 0.4 m / s. However, A _O ²
Need to understand that can be selected to optimize certain ride characteristics. The value of A ² is A _O
If greater than ² , then the solenoid 124 is activated during compression to produce a tight compression stroke, as shown in step 276, while it remains inactive during rebound, Generates a firm rebound stroke. A ² values, when A _O ² equal to or smaller than, the actuation of the solenoid 124 is maintained in a state that does not convert it from a previous state. The process then either returns to step 268 through step 278, or
Alternatively, go to the initial steps of the other method. By using the above method, the shock absorber 20 provides maximum damping force when the frequency of vertical movement of the wheels of the vehicle 22 is substantially equal to a value of 10 to 15 Hz.

During compression and rebound, the piston 44
The method shown in FIG. 14 can be used to prevent the piston rod 46 from moving excessively in the axial direction. In step 280, the differential pressure between the upper and lower portions of working chamber 42 is recorded. In step 282, the computer 202 determines whether the shock absorber 20 is in compression or in rebound by determining the value of the differential pressure.
As shown in step 284, the shock absorber 20
Is in compression and the solenoid 124 is actuated producing a tight compression stroke, the process passes through step 286 and returns to step 280, or to the initial step of another method. . If the compression stroke is soft, then in step 288, the piston speed V _piston is determined by comparing the differential pressure recorded by the pressure sensor 180 to a pressure / piston speed table stored in the memory of the computer 202. It As shown in step 290, the absolute value of the piston velocity V _piston is a predetermined value V _O (generally 0.4 m
/ S), solenoid 124 is de-energized or deactivated, which results in step 29
At 2, a tight compression stroke is generated. The process then goes through step 286 and either returns to step 280 or goes to the initial step of the other method.

The shock absorber 20 proceeds to step 28.
If the computer 202 determines in step 2 that the rebound state is present, the computer 202 determines whether the solenoid 124 is generating a hard rebound stroke or a soft rebound stroke, as shown in step 294. judge. If the rebound stroke is soft, the process proceeds to step 28.
6, go back to step 280 or go to the initial step of the other method. If the rebound stroke is soft, then in step 296 the differential pressure between the upper and lower portions of the working chamber 42 is compared to a pressure / piston velocity table stored in the memory of the computer 202, Piston speed V
_{The piston} is decided. If the value of the piston velocity V _piston is greater than the predetermined value V _O ′, as shown in step 298, then the computer 202 deenergizes the solenoid 124 in step 300 to produce a hard rebound stroke. If the value of the piston velocity V _piston is less than the predetermined value V _O ', the process passes through step 286 and returns to step 280, or
Go to the initial steps of another method. By using the above method, shock absorber 20 provides maximum damping force when vertical movement of the wheels of motor vehicle 22 would otherwise cause excessive compression or contraction of shock absorber 20. Can bring

A second preferred embodiment of the invention is shown in FIG.
Is shown in. In this example, the valve body 302 includes an upper surface 304 having a recessed portion 306 and a lower surface 308 having a recessed portion 310. The valve body 302 is further provided with a plurality (first) to allow fluid communication between the upper and lower portions of the working chamber 42.
And second) vertical flow passages 312, 314. The flow passages 312, 314 extend between the upper surface 304 of the valve body 302 and the lower surface 308 of the valve body 302. Each flow passage 312 has a valve controlled outlet end 316 that faces a counterbore inlet end 318. Similarly, each flow passage 314 has a valve-controlled outlet end 320 that faces a counterboreed inlet end 322.

Two valve disks 324, 326 are provided to provide a means for controlling the flow of damping fluid between the upper and lower portions of the working chamber 42. The valve disks 324 and 326 are coaxially arranged adjacent to the upper surface 304 and the lower surface 308 of the valve body 302, respectively. Valve disc 324
Have a diameter sufficient to align with and cover the exit end 316 of the flow passage 312, thereby preventing dampening fluid from entering the exit end 316. However,
The valve disc 324 does not cover the counterbore inlet end 322 of the flow passage 314, thereby allowing damping fluid to enter the counterbore inlet end 322. The valve disc 324 also cooperates with the recessed portion 306 of the upper surface 304 of the valve body to form a first pressure chamber 328.

In this regard, the valve disc 326
Has a diameter that matches and covers the outlet end 320 of the flow passage 314, but does not cover the spotted inlet end 322. The valve disc 326 also cooperates with the second recessed portion 310 of the lower surface 308 of the valve body 302 to form a second pressure chamber 330.

In order to support the valve body 302 in the pressure cylinder 40, the valve body 302 has a central hole 3
32, the central bore can use an axially extending piston post 334. The piston post 334 has an upper portion (not shown) having an internally threaded central hole which is threadably engaged with the externally threaded lower end of the piston rod 46. To meet. An o-ring or similar sealing element 336
It is provided between the valve body 302 and the piston post 334 to prevent damping fluid from flowing between the valve body and the piston post. Two axially extending flow passages 340 are provided in the piston post 334, the two flow passages 340 of the valve body 302 extending from the pressure chamber 328 to the central bore 332 of the valve body 302. Is in communication with. Also,
The piston post 334 also includes two radially extending flow passages 346 that communicate with two flow passages 348 extending from the pressure chamber 330 to the central bore 332 of the valve body 302. Flow passage 34
0-348 allows damping fluid to flow between the pressure chamber 328 and one of the solenoids described below. The piston post 334 further includes a radially extending step 349 having an outer diameter greater than the diameter of the central bore 332. Since the step 349 is arranged above the valve body 302, the step 349 restricts the upward movement of the valve body 302 relative to the piston post 334. A piston retaining nut 350 having an internally threaded hole 352 is also provided, which is located below the valve body 302 and is threaded to the externally threaded lower portion 354 of the piston post 334. Engage in the formula. Since the outer diameter of the piston holding nut 350 is larger than the diameter of the central hole 332 of the valve body 302, the nut 350 is
Valve body 3 relative to piston post 334
Prevents downward movement of 02. Piston post 334
And the piston retaining nut 350 also serves to secure the innermost portion of the valve discs 324,326.
In this regard, the innermost portion of the valve disc 324 has a radially extending step 3 of the piston post 334.
49 as well as the upper surface 304 of the valve body 302. Further, the radially innermost portion of the valve disc 326 engages with the lower surface of the valve body 302 and the piston holding nut 350.

To bias the valve discs 324, 326 toward the surfaces 304, 308 of the valve body 302, a pair of coaxially coiled and axially spaced spiral coil springs 356, 358 are provided. It is provided. The spring 356 is formed on the piston post 334 and extends in the radial direction, and the step portion 360 and the valve disc 324.
Plate 3 adjacent to the upper surface of the and coaxially arranged with the upper surface
62, and is arranged coaxially with the piston post 334. The spring 356 can elastically and yieldably bias the valve disc 324 toward the upper surface 304 of the valve body 302 via the intermediate receiving plate 362. Similarly, a spring 358 is provided between a radially extending flange 364 of the piston retaining nut 350 and a receiving plate 366 adjacent the valve disc 326 and coaxially arranged with the valve disc 326. Therefore, the spring 358 causes the valve disc 326 to move to the surface 308 of the valve body 302 by means of the intermediate receiving plate 366.
Can be elastically and yieldably biased.

The piston 44 further includes first and second pistons 44 to provide an electrically controllable flow means operable to control the operation of the valve discs 324, 326.
The solenoids 370 and 372 are provided. The solenoid 370 has a housing 374 provided in the central hole 375 of the piston post 334. Within the housing 374 is a coil 376 and an armature 378 having an enlarged counterbore 380. Armature 378 has counterbore 380
A helical coil spring 382 provided inside the shaft is biased axially downward relative to the valve body 320. The lower end of spring 382 is in pressure contact with the lower portion of counterbore 380, while spring 382
The upper end of the is pressed against the lower side of the seal plate 384. Similarly, the solenoid 372 also has a central hole 3 of the piston post 334 at a position below the solenoid 370.
The housing 38 includes a housing 386 arranged coaxially with the central hole. Within the housing 386 is a coil 388 and an armature 390 having an enlarged counterbore 392. The armature 390 is axially biased upward relative to the valve body 302 by a spiral coil spring 394 provided in the counterbore 392. Spring 3
The upper end of 94 is in pressure contact with the upper surface of counterbore 392, while the lower end of spring 394 is the seal plate 39.
It is pressed against the upper surface of 6.

Counter bore 380 of solenoid 370
The lower axial end of the has an axial flow passage 398, which is coaxially arranged with the axial flow passage 400 in the housing 374. Similarly, the lower axial end of the counterbore 392 of the solenoid 372 has an axial flow passage 402 that is coaxially aligned with the axial flow passage 404 in the housing 386. Has been done. The pressure sensor 406 is connected to the flow passage 4
Since it is provided between housings 374 and 386 adjacent to 00 and 404, the pressure sensor 406 is
The differential pressure between the damping fluid in solenoid 370 and the damping fluid in solenoid 372 can be determined. The output from the pressure sensor 406 and the output from the accelerometer 408 are supplied to a signal conditioning circuit 198, which amplifies the output before supplying it to the computer 202. Next, the computer 202 causes the solenoids 370 and 372 via the solenoid drive circuit 204.
First and second electrical control signals are generated to control the.

The solenoid 370 is the seal plate 38.
Operatively co-operating with 4 to control damping fluid between the central flow passage 410 and a plurality of radially displaced passages 412 provided in the seal plate 384. Solenoid 3
When the 70 is open, damping fluid can flow between the central flow passage 410 and the radially displaced passage 412. When the solenoid 370 is closed, the armature 378 moves downward against the force of the spring 382 to a position in sealing engagement with the seal plate 384.
When this state is reached, the armature 378 will pass through the passage 410.
And 412 to prevent fluid flow. Similarly, the solenoid 372 cooperates with the seal plate 396 to control damping fluid between the central flow passage 414 and the plurality of radially displaced flow passages 416 provided in the seal plate 396. . When the solenoid 372 is open, damping fluid can flow between the central flow passage 414 and the radially displaced flow passage 416. When the solenoid is closed, the armature 390
It moves downwards against the force of the spring 394 to a position that sealingly engages the seal plate 396. When this occurs, armature 390 blocks fluid flow between passages 414 and 416.

The solenoid 370 corresponds to the piston post 33.
4 through an axial passage 422 and a radial passage 424 to the upper part of the working chamber 42. The axial passage 422 is defined by the central passage 41 of the seal plate 384.
It extends from 0 and communicates with the radially innermost end of the radial passage 424. Further, the solenoid 372 communicates with the lower portion of the working chamber 42 through the central hole 426 of the solenoid holding plug 428. The solenoid retention plug 428 has a threaded outer surface that threadably engages the lower portion of the piston post 334.

The valve body 302 further includes flow passages 430, 432 to allow fluid to flow through the passages 410-418 and bias the valve discs 324, 326 in opposite directions. . The flow passage 430 extends radially from the pressure chamber 328 to the vertical flow passage 312, while the flow passage 432 extends from the pressure chamber 330 to the flow passage 314. Thus, the damping fluid in flow passage 312 can enter pressure chamber 328 via flow passage 430, and the damping fluid in flow passage 314 via flow passage 432.
The pressure chamber 330 can be entered.

It will be appreciated that, according to the principles of the present invention, two flow paths are formed in the valve body 302. The first
The flow path of allows the damping fluid to enter the flow passage 312 and flow to the upper portion of the working chamber 42. In this regard, the first flow path allows the damping fluid in the vertical flow passage 312 to enter the pressure chamber 328 via the flow passage 430. Next, the pressure chamber 32
The damping fluid in FIG.
2 and through the flow passage 340 of the piston post 334 to the flow passage 412 displaced in the radial direction of the seal plate 384. If the solenoid 370 is open, the damping fluid in the radially displaced flow passage 412 is
Through the second central flow passage 410, the axial flow passage 422, and the radial flow passage 424, the working chamber 4
2 can flow to the upper part.

The second flow path allows damping fluid flowing in the vertical flow passage 314 to enter the lower portion of the working chamber 42. In this regard, the second flow path allows the damping fluid in flow path 314 to flow through flow path 432.
Allow entry into pressure chamber 330. Therefore, the damping fluid in the pressure chamber 330 is transferred to the valve body 302.
A radially extending flow passage 346 and a piston post 334 radially extending flow passage 348.
Through the seal plate 396 to the radially displaced flow passage 416. If the solenoid 372 is open, the damping fluid supplied to the radially displaced passage 416 of the seal plate 396 will flow through the central flow passage 314 and through the central fluid passage 414 of the solenoid seal plate 396. Through which it can flow to the lower part of the working chamber 42.

An annular retaining seal 434 is provided to prevent leakage of damping fluid into the pressure chamber 328. An annular retaining seal 434 is provided on the valve disc 3
Located within pressure chamber 328 adjacent to 24, thereby preventing dampening fluid within pressure chamber 328 from entering the upper portion of working chamber 42. An annular retaining ring 436 is also provided within the pressure chamber 328 to displace the seal 434 and cause the pressure chamber 328 to move.
The hydraulic pressure does not leak between the upper part of the working chamber 42 and the upper part of the working chamber 42. Similarly, an annular retaining ring 438
Adjacent the valve disc 326, the chamber 330
It is provided inside. The annular retaining ring 438 allows the damping fluid in the pressure chamber 330 to move through the working chamber 42.
Used to prevent entry into the lower part of the.
An annular retaining ring 440 is also provided in the pressure chamber 330 to displace the seal 438 to prevent leakage of damping fluid between the pressure chamber 330 and the lower portion of the working chamber 42.

When a large amount of working fluid needs to flow into the flow passage 314 for a soft rebound stroke, the solenoid 372 is closed, which causes radial displacement of the central fluid passage 414 and seal plate 396. The flow of fluid to and from the passageway 416. Thus, the damping fluid in pressure chamber 328 can be used to flow into the lower portion of working chamber 42. Therefore, the pressure in pressure chamber 330 increases, which increases the reverse biasing force exerted on valve disc 326. Next, the valve disc 3
26 flexes from the valve body 302 to a greater extent than would otherwise occur, which
Increasing the flow rate of damping fluid through flow passage 314. If a tight rebound stroke is desired, solenoid 372 is opened so that the pressure in pressure chamber 330 is substantially equal to the pressure in the lower portion of working chamber 42. In such a state, the reverse biasing force applied to the valve disc 326 decreases.
Therefore, a smaller amount of damping fluid can flow through the flow passage 314, thus producing a tight rebound stroke.

If a soft compression stroke is desired, solenoid 370 is closed, which allows damping fluid flow between central fluid passage 410 and fluid passage 412 radially displaced at seal plate 384. Block. Since fluid cannot flow between passages 410 and 412, damping fluid in pressure chamber 328 cannot flow into the upper portion of working chamber 42. Since the pressure of the damping fluid in the pressure chamber 328 is higher than the pressure in the upper portion of the working chamber, the reverse biasing force exerted on the valve disc 324 is increased, making the valve disc 324 larger. Bend. This increased deflection of the valve disc 324 increases the flow rate of the damping fluid through the flow passage 312, thereby creating a softer compression stroke. If a tight compression stroke is desired, solenoid 370 is opened, thereby connecting pressure chamber 328 to the upper portion of working chamber 42. Therefore, the pressure chamber 3
The pressure in 28 is substantially equal to the pressure in the upper part of the working chamber 42, whereby the valve disc 3
Limit the reverse biasing force applied to 26.

In a third preferred embodiment of the invention, shown in FIG. 16, annular first and second valve action members 44.
2, 444 are provided. The annular first and second valve action members 442 are coaxially arranged in the first pressure chamber 90 and the second pressure chamber 94, respectively. Annular retaining seals 446, 448 are provided between the annular first valve action member 442 and the valve body 66 to prevent hydraulic leakage between such valve action member and valve body. . Similarly, two annular retaining seals 450, 452 are provided between the annular second valve action member 444 and the valve body 66, and these retaining seals also prevent leakage of hydraulic pressure. The first annular valve action member 442 has an unloader port 454 provided between the first pressure chamber 90 and the upper portion of the working chamber 42. This unloader port 454
Adjacent to the upper portion of the working chamber 42 has an enlarged diameter portion 456 which may be used to house a filter for filtering the dampening fluid. it can. Also, unloader port 4
54 also has a reduced diameter portion 458 adjacent the first pressure chamber 90. Enlarged diameter part 45
The diameter of 6 is about 1.27 mm (0.050 inch),
Further, the reduced diameter portion 458 has a diameter of 0.33 mm (0.
013 inches), but it should be understood that other suitable diameters can be used. The unloader port 454 functions in a manner similar to the flow passage 162 described in connection with the first preferred embodiment of the present invention.

Further, a third preferred embodiment of the present invention is
It has a flow passage 460 extending radially from the flow passage 105 to the flow passage 160. The flow passage 460 functions similarly to that described with respect to the first preferred embodiment of the present invention.

In operation, the damping fluid is the solenoid 1
Depending on whether 24 is open, it flows into the flow passage 160 via the flow passage 460. The damping fluid in flow passage 160 is then supplied to first pressure chamber 90, which biases valve disc 72 to regulate the flow of damping fluid through vertical flow passage 68. be able to. Reduced diameter portion 45 of unloader port 454
Because 8 is relatively small, the pressure in the first pressure chamber 90 remains relatively constant during compression. During rebound, damping fluid from the upper portion of working chamber 42 enters first pressure chamber 90 via unloader port 454. The damping fluid entering the unloader port 452 can then flow from the first pressure chamber 90 to the second pressure chamber 94 via the flow passage 160. Depending on whether the solenoid 124 is open, the damping fluid flows from the second pressure chamber 94 to the flow passages 460, 105, 155 and 156 and the central bore 1.
It can flow via 54 to the lower part of the working chamber 42, whereby the pressure in the second pressure chamber 94 can be adjusted.

It will be appreciated that the preferred embodiments disclosed herein have been successfully designed to meet the above objectives, but may be modified without departing from the scope of the invention. It will be appreciated that variations and modifications can be made. For example, a single computer can be used to control the damping characteristics of several shock absorbers simultaneously. Further, the damping characteristic of the automobile 22 can be controlled by using another program, and the programs disclosed in this specification can be used individually or in combination. Also, both the pressure sensor and the accelerometer can be provided in the solenoid housing. Further, the solenoid can be replaced by other means for opening and closing control flow for the various valves, such as a piezo effect closure element.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a device for absorbing mechanical shock according to a preferred embodiment of the present invention in operative association with a typical vehicle.

2 is a side view, partly broken away, of the device for absorbing mechanical shock of the first preferred embodiment of the invention shown in FIG. 1; FIG.

FIG. 3 is an exploded and enlarged perspective view of a piston according to a first preferred embodiment of a device for absorbing mechanical shock as shown in FIG.

4 is an exploded and enlarged perspective view of a piston according to a first preferred embodiment of a device for absorbing mechanical shock as shown in FIG.

5 is an enlarged longitudinal sectional view of the piston according to the first preferred embodiment of the present invention as shown in FIG. 2. FIG.

6 is an enlarged cross-sectional view of the piston shown in FIG. 5, showing the operation of the piston according to the first preferred embodiment of the present invention.

7 is an enlarged cross-sectional view of the piston shown in FIG. 5, showing the operation of the piston according to the first preferred embodiment of the present invention.

FIG. 8 is an enlarged sectional view of the piston shown in FIG. 5, showing the operation of the piston according to the first preferred embodiment of the present invention.

9 is an enlarged cross-sectional view of the piston shown in FIG. 5, showing the operation of the piston according to the first preferred embodiment of the present invention.

FIG. 10 is a block diagram showing how the outputs from the pressure sensor and accelerometer are used to activate the solenoid of the first preferred embodiment of the present invention as shown in FIG.

11 is a schematic circuit diagram of the drive circuit shown in FIG.

FIG. 12 is a flow chart showing a method for coaxing movement of a vehicle body that can be used with a device for damping mechanical shock according to the first and second preferred embodiments of the present invention.

FIG. 13 is a method for minimizing vibration of a wheel or an unsprang mass of a motor vehicle, which can be used with a device for damping mechanical shocks according to the first and second preferred embodiments of the present invention. It is a flowchart showing.

FIG. 14 prevents excessive axial movement of the piston during compression and rebound, which can be used with a device for damping mechanical shock according to the first and second preferred embodiments of the present invention. 4 is a flowchart showing a method for doing so.

FIG. 15 is a diagram according to a second preferred embodiment of the present invention;
FIG. 4 is an enlarged longitudinal sectional view showing the device for absorbing the mechanical shock shown in FIG.

FIG. 16 is a diagram of FIG. 1 according to a third preferred embodiment of the present invention.
FIG. 4 is an enlarged longitudinal sectional view showing the device for absorbing the mechanical shock shown in FIG.

[Explanation of symbols]

 20 Shock Absorber 22 Automobile 40 Pressure Cylinder 42 Working Chamber 66 Valve Body 68, 70 Flow Path 84, 86 Valve Disc 90, 94 Pressure Chamber 98 Piston Post 105, 106 Flow Path 108 Piston Holding Nut 113, 114 Spring 124 Solenoid 126 Housing 132 Armature 140 Seal plate 153 Solenoid holding plug 155, 156 Flow passage 160, 162 Flow passage

Front Page Continuation (72) Inventor Magnus B. Risel New York, USA 10003, New York, East Twelves Street 60, Number 10-Dee

Claims (48)

[Claims] 1. A direct-acting hydraulic shock absorber for damping movement of a vehicle body, the pressure cylinder forming a working chamber having first and second portions capable of containing a damping fluid. A first valve means for controlling the flow of damping fluid between the first and second portions of the working chamber while the shock absorber is compressed; and the first valve of the working chamber. Electrically controlled to regulate the flow of damping fluid between the pressure chamber and the second portion of the working chamber and a pressure chamber in fluid communication with the first valve means. Possible communication means and while the shock absorber is rebounding,
Second valve means for controlling the flow of dampening fluid between the first and second portions of the working chamber, the hydraulic shock absorber. 2. The shock absorber of claim 1, wherein the electrically controllable communication means is operable to control the pressure of damping fluid in the pressure chamber. Absorber. 3. The shock absorber according to claim 1, further comprising first spring means for biasing the first valve means in a first direction. 4. The shock absorber of claim 3 wherein the pressure of the dampening fluid in the pressure chamber causes the first valve means to oppose the biasing force exerted by the first spring means. A shock absorber characterized in that it is operable to bias in the direction of. 5. The shock absorber of claim 1, wherein the second valve means is provided for dampening fluid between the first and second portions of the working chamber while the shock absorber is rebounding. A shock absorber further comprising second spring means for biasing the flow restrictive position. 6. The shock absorber according to claim 1, wherein the second valve means comprises a valve disc. 7. The shock absorber according to claim 1, wherein the electrically controllable communication means includes a solenoid. 8. The shock absorber of claim 7, wherein the solenoid is at least partially provided in the pressure cylinder. 9. The shock absorber of claim 7, wherein the solenoid comprises an armature, the armature controlling a flow of damping fluid between the pressure chamber and the second portion of the working chamber. A shock absorber characterized by being operable. 10. The shock absorber of claim 9, wherein the armature causes the second chamber of the pressure chamber and the working chamber when the solenoid is open.
A shock absorber operable to allow fluid communication with a portion of the shock absorber. 11. A direct actuated hydraulic shock absorber for damping movement of a vehicle body, the pressure cylinder forming a working chamber having first and second portions capable of containing a damping fluid. A first valve means for controlling the flow of damping fluid between the first and second portions of the working chamber while the shock absorber is compressed; and containing damping fluid. A pressure chamber, wherein the pressure chamber is provided in the pressure cylinder and is capable of biasing the first valve means in a first direction by a pressure of a damping fluid contained therein; A first flow passage between the first portion of the working chamber and the pressure chamber, and a second flow passage between the second portion of the working chamber and the pressure chamber Electrically controllable communication means for regulating the flow of dampening fluid through the second flow passage and the first and second working chambers of the working chamber during rebound of the shock absorber. Second valve means for controlling the flow of dampening fluid between the two parts of the hydraulic shock absorber. 12. The shock absorber of claim 11 wherein the electrically controllable communication means is operable to control the pressure in the pressure chamber. 13. The shock absorber of claim 11 for biasing said first valve means in a second direction opposing a biasing force generated by pressure inside said pressure chamber. 1. A shock absorber, characterized in that it further comprises one spring means. 14. The shock absorber of claim 11, wherein the second valve means is provided for dampening fluid between the first and second portions of the working chamber while the shock absorber is rebounding. A shock absorber further comprising second spring means for biasing the flow restrictive position. 15. The shock absorber according to claim 11, wherein the second valve means comprises a valve disc. 16. The shock absorber according to claim 11, wherein the electrically controllable communication means includes a solenoid. 17. The shock absorber according to claim 16, wherein the solenoid is provided at least partially in the pressure cylinder. 18. The shock absorber according to claim 16, wherein the solenoid has an armature.
A shock absorber, wherein the armature is operable to regulate a flow of damping fluid through the second flow passage. 19. The shock absorber of claim 18, wherein the armature allows fluid communication between the pressure chamber and the second portion of the working chamber when the solenoid is open. A shock absorber characterized by being operable. 20. A direct actuated hydraulic shock absorber for damping movement of a vehicle body, the pressure cylinder defining a working chamber having first and second portions capable of containing damping fluid. First valve means for controlling the flow of damping fluid between the first and second portions of the working chamber while the shock absorber is being compressed; and the first valve. A first spring operable to bias the means in a first direction; and a pressure chamber provided in the pressure cylinder operable to contain a damping fluid, the pressure chamber comprising: A pressure chamber, wherein the pressure of the inner damping fluid is operable to bias the first valve means in a second direction that opposes the biasing force provided by the first spring; A first flow passage between the first portion of the working chamber and the pressure chamber; a second flow passage between the second portion of the working chamber and the pressure chamber; An electrically controllable communication means operable to regulate the flow of damping fluid through the two flow passages and control the pressure in the pressure chamber, while the shock absorber is rebounding. To
Second valve means for controlling the flow of damping fluid through the first and second portions of the working chamber. 21. The shock absorber of claim 20, wherein the second valve means comprises a valve disc. 22. The shock absorber of claim 21, wherein the valve disc restricts flow of damping fluid between the first and second portions of the working chamber while the shock absorber is rebounding. The shock absorber further comprising a second spring operable to bias the actuator to an operable position. 23. The shock absorber according to claim 22, wherein the electrically controllable communication means comprises a solenoid. 24. The shock absorber according to claim 23, wherein the solenoid is at least partially provided in the pressure cylinder. 25. The shock absorber of claim 24, wherein the solenoid comprises an armature.
A shock absorber, wherein the armature is operable to control the flow of damping fluid between the pressure chamber and the second portion of the working chamber. 26. The shock absorber of claim 25, wherein the armature allows fluid communication between the pressure chamber and the second portion of the working chamber when the solenoid is open. A shock absorber characterized by being operable. 27. A method for regulating the flow of damping fluid between first and second working chambers of a direct actuated hydraulic shock absorber, the method comprising: The damping fluid inside,
A damping fluid is contained in a pressure chamber operable to contain a damping fluid, the flow of the damping fluid from the first portion of the working chamber to the second portion of the working chamber is Responsive to the pressure of the shock absorber, allowing selective fluid communication between the pressure chamber and the second portion of the working chamber while the shock absorber is being compressed, Adjusting the flow of damping fluid from the first part of the working chamber to the second part of the working chamber, while the shock absorber is being rebound,
Adjusting the flow of damping fluid from the second portion of the working chamber to the first portion of the working chamber. 28. The method of claim 27, wherein the step of admitting a damping fluid in the first portion of the working chamber into a pressure chamber comprises a damping fluid in the pressure chamber during compression. And allowing fluid communication between the first valve means and a first valve means for controlling the flow of damping fluid between the first and second portions of the working chamber. 29. The method of claim 28, wherein the first
The valve means is biased in a first direction by a first spring. 30. The method of claim 29, wherein the pressure of the dampening fluid in the pressure chamber causes the first valve means to oppose the biasing force exerted by the first spring. A method characterized by being operable to bias. 31. The method of claim 27, wherein during rebound, adjusting the flow of damping fluid from the second portion of the working chamber to the first portion of the working chamber comprises: Allowing the damping fluid in the second portion of the working chamber to flow into the first portion via second valve means for regulating the flow of the damping fluid. A method characterized by. 32. The method of claim 31, wherein the second
The valve means of claim 1 includes a valve disc. 33. The method of claim 32, wherein the second
Second valve means is biased to a position by a second spring, the position from the second portion of the working chamber to the first of the working chamber while the shock absorber is rebounding. The method characterized by being able to restrict the flow of dampening fluid to the part of the. 34. The method of claim 27, wherein allowing selective fluid communication between the pressure chamber and the second portion of the working chamber selects electrically controllable communication means. Electrically exciting to regulate the flow of damping fluid between the first and second portions of the working chamber. 35. The method of claim 34, wherein the electrically controllable communication means comprises a solenoid. 36. The method of claim 35, wherein the solenoid is at least partially located within the pressure cylinder. 37. The method of claim 35, wherein the solenoid comprises an armature such that the armature regulates a dampening fluid flow between the pressure chamber and the second portion of the working chamber. A method characterized by being operable. 38. The method of claim 37, wherein the armature is operable to allow fluid communication between the pressure chamber and the second portion of the working chamber when the solenoid is open. A method characterized by being. 39. A method for regulating the flow of damping fluid between first and second portions of a working chamber of a direct-acting hydraulic shock absorber, the method comprising: Flowing a damping fluid in a first flow passage to and from a pressure chamber operable to contain the damping fluid, the pressure of the damping fluid in the pressure chamber biasing the first valve means, Allowing control of the flow of damping fluid between the first and second parts of the working chamber, a second between the second part of the working chamber and the pressure chamber Flowing damping fluid through the second flow passage, selectively blocking flow of damping fluid through the second flow passage while the shock absorber is being compressed, and reshuffling the shock absorber. In between there,
Adjusting the flow of damping fluid from the second portion of the working chamber to the first portion of the working chamber. 40. The method of claim 39, wherein the first
Said valve means is further biased by a first spring in a direction opposing the biasing force exerted by the pressure of the damping fluid in said pressure chamber. 41. The method of claim 40, wherein the step of adjusting the flow of dampening fluid from the second portion of the working chamber to the first portion of the working chamber during rebounding comprises: Damping fluid in the second portion of the working chamber is coupled to the first portion of the working chamber via second valve means for regulating the flow of damping fluid.
A method comprising allowing flow into a portion of the. 42. The method of claim 41, wherein the second
The valve means of claim 1 includes a valve disc. 43. The method of claim 42, wherein the second
Second valve means is biased by a second spring into a position in which the second of the working chamber is
A portion of the working chamber and the first portion of the working chamber are operable to limit the flow of damping fluid. 44. The method of claim 43, wherein the second
Selectively blocking the flow of damping fluid through the second flow passage selectively energizes the electrically controllable communication means to regulate the flow of damping fluid through the second flow passage. A method comprising the steps of: 45. The method of claim 44, wherein the electrically controllable communication means comprises a solenoid. 46. The method of claim 45, wherein the solenoid is at least partially located within the pressure cylinder. 47. The method of claim 46, wherein the solenoid comprises an armature, the armature operable to regulate a flow of damping fluid through the second flow passage. Method. 48. The method of claim 47, wherein the armature is operable to allow fluid communication between the pressure chamber and the second portion of the working chamber when the solenoid is open. A method characterized by being.