RU2253576C2 - Adjustable shock absorber - Google Patents

Abstract

FIELD: transport engineering; vehicle suspensions.

SUBSTANCE: proposed adjustable shock absorber contains piston with double-acting pressure transducer and step electric motor whose armature is stationary secured on rod and inductor is furnished with cover with projecting ring lugs with holes made in lugs. Transducer generates electric signal proportional to speed of piston displacement. Signal is transmitted to control device which generates required number of pulses and conveys them into armature winding of step electric motor. Inductor with cover is turned through angle providing change of passage area of channels in piston to value creating resistance with force which is regulated by program of realized resistance characteristics for specific stroke and speed of displacement of piston.

EFFECT: dispensing with elastic valve members in shock absorbers, enlarged range of resistance characteristic control.

2 dwg

Description

The invention relates to transport machinery, namely to the suspension of vehicles.

An analogue of the claimed invention is a shock absorber [1], comprising a cylinder, a piston, a rod, a guide sleeve, a hydraulic cavity filled with a working fluid and divided by a piston into lower and upper parts connected by piston channels, as well as valves with elastic elements, a gas cavity and a separator separating it from the hydraulic cavity.

The parameters of the elastic elements uniquely determine the characteristic of the resistances (the dependence of the resistance forces on the speed of movement of the piston) of the shock absorber, as a result of which the analog design allows only one such characteristic to be realized.

The values of the resistance forces of the shock absorber with valves based on elastic elements have a tolerance field. In this regard, the actual resistance forces may differ from their nominal values.

In addition, the resistance forces of the analog during operation decrease with time due to a decrease in the stiffness of the elastic elements.

The prototype of the claimed invention is an adjustable shock absorber [2], containing a cylinder, piston, rod, hydraulic cavity filled with a working fluid and divided by a piston into lower and upper parts connected by channels, as well as valves with elastic elements and a control device associated with an electric motor . The rotor of the electric motor, which is functionally its anchor, is connected to the regulating element in the form of a spool placed in the stem and having the ability to rotate in it. The motor housing, which performs the function of an inductor (magnetic field source) with permanent magnets, is mounted motionless on the stem of the rod. In order to ensure the supply of current to the armature winding, which has the ability to rotate, the electric motor is equipped with a current collector.

The design of the prototype partially eliminates the disadvantages inherent in the analogue. By turning the slide valve in one direction or another, one of two values of the passage section of the channel connecting the two parts of the hydraulic cavity is established. By varying the bore, a change in the characteristics of the resistance of the shock absorber is provided.

However, the values of the resistance forces of the prototype are determined, like the analogue, by the parameters of the elastic valve elements. In addition, the presence of only two values of the flow area of the adjustable channel makes it possible to implement only two characteristics of the resistance of the shock absorber. In addition, the placement of the regulating element (valve) in the rod imposes restrictions on the range of regulation of this characteristic.

The technical task of the claimed invention is the exclusion from the shock absorber of the elastic valve elements and the expansion of the range of regulation of its resistance characteristics.

The technical problem is solved in that an adjustable shock absorber has a double-acting pressure sensor in one of the piston channels, while the armature of the stepper motor is connected to the control device and fixedly mounted on the rod, and the inductor of the stepper motor is placed in the piston with the possibility of rotation relative to the armature and is made with a flat cap having protruding annular sectors with holes for changing the bore of the piston channels.

The figure 1 shows a General view of an adjustable shock absorber.

The adjustable shock absorber comprises a cylinder 1, a rod 2 with wires 3 located therein, a guide sleeve 4, a piston 5, a hydraulic cavity 6, divided by a piston 5 into lower and upper parts, as well as a gas cavity 7 and a separator 8 separating the hydraulic cavity 6 from the gas cavity 7. The lower and upper parts of the hydraulic cavity 6 are interconnected by channels 9 of the piston 5.

In one of the channels 9 of the piston 5, a double-acting pressure sensor is located, which consists of the lower and upper piezoelectric plates 10, as well as a metal disk 11 located between them. It serves as a common wire of the plates 10 included in the electric control circuit of a stepper motor. The anchor 12 of the stepper motor is fixedly mounted on the rod 2. In the piston 5 along with the pressure sensor is placed an inductor 13 (with permanent magnets) of the stepper motor with the possibility of rotation relative to the armature 12 of the stepper motor. The flat cover 14 of the inductor 13 has protruding annular sectors 15 with holes made in them. The anchor 12 of the stepper motor is connected by wires 3 to the control device 16 (not shown in figure 1).

The control circuit of the stepper motor is shown in figure 2. The circuit includes a control device 16 that generates control pulses depending on the pressure of the working fluid and feeds them into the winding 17 (not shown in figure 1) of the armature 12 (figure 1) of the stepper motor. The control device 16 (figure 2) provides the possibility of implementing the characteristics of the resistances in a wide range of forces, regulated by the reliability of the shock absorber.

The shock absorber works as follows.

When the pressure of the working fluid is equal in both parts of the hydraulic cavity 6 (figure 1), the inductor 13 together with its cover 14 are in the extreme position of movement counterclockwise on (section AA). This position is the starting position for the stepper motor. In this state, the channels 9 from one part of the hydraulic cavity 6 to another part are completely blocked by the annular sectors 15 of the cover 14.

When compressed, the piston 5 begins to move downward, as a result of which the pressure of the working fluid in the lower part of the hydraulic cavity 6 becomes greater than in its upper part. The pressure sensor generates an electrical signal at which a positive potential is formed on the lower piezoelectric plate 10 of the sensor. The magnitude of the signal is proportional to the pressure of the liquid and, therefore, the speed of movement of the piston 5. The positive potential of the lower plate 10 serves as a command to the control device 16 (figure 2) to generate an effect on the change in the bore of the channels 9 (figure 1) in accordance with the compression branch program on the implemented characteristic shock absorber resistances. The control device 16 (figure 2) generates the required number of current pulses and transfers them to the winding 17 of the armature 12 (figure 1) of the stepper motor. In accordance with the indicated number of pulses, the inductor 13 together with the cover 14 is rotated through an angle providing a change in the passage section of the channels 9 to a value that creates compression resistance with a force that is regulated by the program of the implemented characteristic for a specific piston moving speed during compression. The bore is changed by changing the degree of overlap of the channels 9, designed for the flow of the working fluid, annular projections 15 of the cover 14 of the inductor 13 when the latter is rotated.

When rebound, the piston 5 begins to move upward, as a result of which the pressure of the working fluid in the upper part of the hydraulic cavity 6 becomes greater than in its lower part. The pressure sensor generates an electrical signal in which a positive potential is formed on the upper piezoelectric plate 10 of the sensor. The magnitude of the signal is proportional to the pressure of the liquid and, therefore, the speed of movement of the piston 5. The positive potential of the upper plate 10 serves as a command to the control device 16 (figure 2) to generate an effect on the change in the passage section of the channels 9 (figure 1) in accordance with the rebound branch program on the implemented characteristic shock absorber resistances. The control device 16 (figure 2) generates the required number of current pulses and transfers them to the winding 17 of the armature 12 (figure 1) of the stepper motor. In accordance with the indicated number of pulses, the inductor 13 together with the cover 14 is rotated through an angle, providing a change in the passage section of the channels 9 to a value that creates a rebound resistance with a force that is regulated by the program of the implemented characteristic for a specific piston speed during rebound. The bore is changed by changing the degree of overlap of the channels 9, designed for the flow of the working fluid, annular projections 15 of the cover 14 of the inductor 13 when the latter is rotated.

The maximum resistance force realized in the shock absorber is achieved when the inductor 13 together with its cover 14 are in the extreme position of clockwise movement (at section AA). This position is the “stop” for the stepper motor. In this state, the channels 9 intended for the flow of the working fluid are fully open.

Comparative analysis with the prototype shows that the inventive shock absorber is characterized in that a pressure sensor of double-acting action is placed in one of the piston channels, while the armature of the stepper motor is connected to the control device and fixedly mounted on the rod, and the inductor of the stepper motor is placed in the piston with the possibility of rotation relative to anchors and is made with a flat cover having protruding annular sectors with holes for changing the bore of the piston channels.

The above signs allow us to conclude that the claimed invention meets the criterion of "novelty."

Existing mechanical engineering technologies and the materials used in it allow organizing the industrial production of adjustable shock absorbers and equipping them with vehicles.

Sources of information

1. Raimpel J. Car chassis. Shock absorbers, tires and wheels. M .: “Mechanical Engineering”, 1986, p. 33, fig. 1.30 (analogue).

2. KAYABA 443218 shock absorber (Nissan 56210) for Nissan Bluebird, Bluebird U (VRU 11, VEU 11) cars. 10.1983 - 1986. Catalog “KAYABA 2001. SHOCK ABSORBER”. KAYABA Europe GmbH Breit Strasse 10B 40670 Meerbusch Germany, p. 116 (prototype).

Claims (1)

An adjustable shock absorber comprising a cylinder with a hydraulic cavity, a rod, a piston dividing the hydraulic cavity into lower and upper parts interconnected by piston channels, and a control device associated with a stepper motor, characterized in that double-acting pressure sensors are placed in the piston channels, the anchor of the stepper motor is connected to the control device and fixedly mounted on the rod, and the inductor of the stepper motor is placed in the piston with the possibility of rotation relative to tionary armature and adapted to flat lid having a protruding ring sectors with holes for changing the flow cross section of the piston channels.

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