RU109698U1 - AIR SUSPENSION - Google Patents

Abstract

 An air suspension containing a rubber-cord casing with a lid, forming a working cavity, an additional capacity and a valve device, in which a rod is installed in the form of an elastic rod and a cylinder with a piston, forming a ring cavity with a casing connected to the cavity of the additional capacity and to the cavity of the rubber-cord shell through radial bypass holes closed by elastic elements fixed on the outer surface of the housing, and connected to the cylinder cavity through radial channels, is made in the middle part of the cylinder, which forms a supra-piston and a sub-piston cavity with a piston, characterized in that the valve device is made in the form of a damping assembly, self-regulating in the direction of relative and absolute vibrations, the body of which is placed along the axis of the suspension in the cavity of the additional container rigidly fixed to the cover, the supra-piston cavity is in communication with the cavity of the additional capacity, the sub-piston cavity is in communication with the working cavity, the lower end of the rod is fixed to the upper end of the hollow piston, which is the support th rubber-cord shell, and radial channels are at a distance less than the height of the piston.

Description

The invention relates to the suspension of vehicles, in particular to pneumatic suspensions with an air damper, self-regulating in the direction of relative and absolute vibrations.

Known pneumatic suspension, containing a rubber-cord shell with a cover, forming a working cavity, an additional capacity and a partition located between them with a valve device, which includes a cylinder mounted along the axis of the suspension and rigidly fixed to the partition, radially located bypass holes fixed in the cover and placed in the cylinder a rod with a piston mounted movably on it, overlapping the bypass holes during the rebound. The valve device equalizes the pressure in the working and additional cavities of the suspension at the very beginning of the compression stroke, as a result of which the natural oscillation frequency is constant and the shock absorbing object is shifted down (AS USSR No. 842295, F16F 9/04, 1981).

The disadvantage of this air suspension is the automatic self-regulation of inelastic resistance only in the amplitude of the deformation of the suspension or relative vibrations of the sprung mass. In this case, the direction of relative and absolute oscillations of the sprung mass is not taken into account, as a result of which the air damping realized by the suspension is not effective enough, since it is carried out, firstly, only during the rebound, and, secondly, due to the presence of absolute phase shift and relative vibrations, the damping force of the suspension on part of its travel can coincide with the direction of motion of the sprung mass, while this force should always be directed against this movement. Other disadvantages are the need for coaxial movement of the cover and additional capacity, which is almost impossible to provide in the suspensions of modern vehicles, and the constant throttling of air through a calibrated hole in the baffle during compression and rebound moves, which causes rapid heating of the elastic element, increases its stiffness and natural vibration frequency . This leads to a decrease in damping properties at the resonant operating modes, where in order to increase the vibration-proof properties of the suspension, its rigidity and damping force must be reduced. In addition, the design of the damping unit in this spring has a limited life due to the presence of a pair of piston friction against the rod.

The closest known technical solutions is a pneumatic suspension containing a rubber-cord shell with a lid, forming a working cavity, additional capacity and a partition located between them with a valve device. Additional capacity is made in the form of a hollow piston elongated along the axis, inside of which a valve device is installed. The valve device is made in the form of a damping assembly that is self-adjustable in amplitude and direction of oscillation, in the housing of which a cylinder with a piston is installed, forming an annular cavity with the housing, connected to the cavity of the additional capacity and to the cavity of the rubber-cord shell through radial bypass openings closed with elastic elements fixed to the outer the surface of the housing, and connected to the cylinder cavity through radial channels made in the middle of the cylinder at a distance equal to the height of the piston . The piston is made in the form of a plunger made of fluoroplastic-4 and forms with the cylinder an over-piston cavity in communication with the cavity of the rubber-cord shell and a under-piston cavity in communication with the cavity of the additional capacity. In a static position, a plunger connected to the cap by an elastic rod is located in the middle of the cylinder between its radial channels, which corresponds to the midpoint of the elastic characteristic (RF patent No. 2340468, F16F 9/04, 2007).

This air suspension has a relatively low technical level due to automatic self-regulation of inelastic resistance only in amplitude and direction of suspension deformation or relative vibrations of the sprung mass. This does not take into account the direction of the absolute oscillations of the sprung mass, which reduces the effectiveness of air damping. In addition, the need to extend the hollow piston in order to place a cylinder with a piston in it, the axial displacements of which are equal to the suspension travel, at high strokes, firstly, leads to an increase in the lateral displacements of the upper part of the hollow piston relative to the axis of the cap, which reduces the reliability and durability rubber-cord sheath and elastic rod, and secondly, to reduce the suspension clearance. Due to the limited dimensions of even an elongated hollow piston, its internal volume is still less than the volume of the working cavity, which reduces damping and smoothness of the vehicle, since in order to ensure effective air damping it is necessary that the additional volume is greater than or equal to the working volume.

In this regard, the most important task is to create a new design of an air suspension with an air damper, which forms a new damping system for automatically controlling its characteristics in the direction of relative and absolute vibrations using a valve device that provides separation of the working and additional cavities when changing the direction of suspension deformation and pressure equalization in these cavities on the paths of compression and rebound at the time of changing the direction of movement of the sprung mass of vehicles but.

The technical result of the claimed air suspension is the automatic self-regulation of inelastic resistance in the direction of relative and absolute oscillations, which leads to an increase in the efficiency of air damping, which results in an improvement in the smoothness of the vehicle.

The specified technical result is achieved in that in a pneumatic suspension containing a rubber-cord shell with a cover, forming a working cavity, an additional capacity and a valve device, in the body of which a rod is installed in the form of an elastic rod and a cylinder with a piston forming an annular cavity connected to the cavity with the body additional capacity and with a cavity of rubber-cord shell through radial bypass holes closed by elastic elements fixed on the outer surface of the housing, and connected with the cylinder cavity through radial channels made in the middle part of the cylinder, which forms the supra-piston and sub-piston cavities with the piston, the valve device is made in the form of a damping unit, self-regulating in the direction of relative and absolute vibrations, the body of which is placed along the axis of the suspension in the cavity of the additional container, rigidly fixed on the lid, the over-piston cavity is in communication with the cavity of the additional capacity, the under-piston cavity is in communication with the cavity of the rubber-cord membrane, the lower end of the rod is fixed on the upper end of the hollow piston, which is the support of the rubber-cord shell, and the radial channels are made at a distance less than the height of the piston.

Due to the fact that the valve device is made in the form of a damping unit, self-regulating in the direction of relative and absolute vibrations, the body of which is placed along the axis of the suspension in the cavity of the additional container rigidly fixed to the lid, the supra-piston cavity is in communication with the cavity of the additional container, the sub-piston cavity is in communication with the rubber-cord cavity shell, the lower end of the rod is mounted on the upper end of the hollow piston, which is the support of the rubber-cord shell, and the radial channels are made at a distance of Higher piston heights, separation of the working and additional cavities when changing the direction of suspension deformation and communication of these cavities with equalization of pressure on the compression and rebound moves almost at the moment of changing the direction of movement of the sprung mass of the vehicle is ensured. As a result of such an algorithm for adjusting the inelastic resistance of the suspension in the direction of relative and absolute vibrations, an increase in the efficiency of air damping is provided, which results in an improvement in the smoothness of the vehicle.

Due to the fact that the additional capacity is rigidly fixed on the cover, the axial dimension of the hollow piston is reduced, which increases the suspension clearance. In addition, the placement of an additional container on the lid allows, without changing the clearance, to increase its internal volume compared to the working volume of the rubber-cord casing, which ensures an increase in the efficiency of air damping, which results in an improvement in the smoothness of the vehicle.

Figure 1 shows the proposed air suspension, a longitudinal section; figure 2 is its working diagram.

The air suspension comprises a rubber-cord shell 1 with a cover 2, on which an additional container 3 is rigidly fixed. The rubber-cord shell 1, a cover 2 and the upper end face of the hollow piston 4, which is a support for the rubber-cord shell 1, form a working cavity 5, which periodically communicates with the cavity 6 of the additional capacity 3 through a valve device made in the form of a damping unit, self-regulating in the direction of relative and absolute vibrations.

The housing 7 of the damping assembly is rigidly fixed at the bottom of the cover 2 and is placed along the axis of the suspension in the cavity 6 of the additional tank 3. In the housing 7, a cylinder 8 is installed, which forms an annular cavity 9 with the housing 7 and connected to the bis cavity 5 through the bypass valves consisting of radial holes 10 and 11, made in the lower part of the housing 7, and covering them with elastic elements 12 and 13, mounted on the outer surface of the housing 7.

In the middle part of the cylinder 8, a piston 14 is installed, connected to the upper end of the hollow piston 4 by means of an elastic rod 15. The annular cavity 9 is connected to the cavity of the cylinder 8 through radial channels 16 and 17 made in the middle of the cylinder 8 at a distance L (Fig. 1) less than the height of the piston 14, which ensures the communication of cavities 5 and 6 almost at the time of changing the direction of movement of the sprung mass of the vehicle. The piston 14 forms a piston cavity 18 connected with the cavity 6 of the additional container 3 with the cylinder 8 and a piston cavity 19 connected with the working cavity 5.

A rubber buffer of the compression stroke 20 is fixed on the upper end of the hollow piston 4, under which a stiffener in the form of a cylinder 21 is installed inside the hollow piston 4. A fitting 22 is installed in the cover 2 and additional capacity 3 for connecting the working cavity 5 with the vehicle body position adjuster.

The proposed air suspension works as follows.

In the absence of suspension oscillations, the piston 14, connected to the upper end of the hollow piston 4 by an elastic rod 15, is located in the middle part of the cylinder 8, overlapping its radial channels 16 and 17. The average position of the piston 14 is provided by connecting the working cavity 5 to the vehicle body position regulator by means of a fitting 22.

When the suspension deforms in a small area of the static stroke, smaller than the distance difference between the height of the piston 14 and the radial channels 16 and 17, the cavities 5 and 6 are not communicated, since the piston 14 overlaps the radial channels 16 and 17. In this mode, the gas pressure changes only in the working cavity 5, which corresponds to the elastic characteristic shown by the dashed line in the area Δ (figure 2). In this case, air damping does not occur, which is necessary to ensure high smoothness when the vehicle is moving along small irregularities, for example, on asphalt with short cracks.

When the suspension moves equal to Δ, at the time of changing the direction of movement of the sprung mass of the vehicle, the piston 14 opens the radial channels 16 and 17, as a result of which the pressure is equalized in the cavities 5 and 6. This corresponds to points 1 and 3 on the elastic characteristic (figure 2) . At high speeds, the suspension works as follows.

During compression of the suspension, the cover 2, from the bottom of which the housing 7 of the damping assembly is fixed, together with the additional capacity 3 move down, the hollow piston 4 with the piston 14 move up, and the lower part of the rubber-cord shell 1 rolls over the outer surface of the hollow piston 4, at the upper end of which fixed the lower end of the elastic rod 15. In this case, the pressure in the working cavity 5 increases, as a result of which the elastic element 13 is pressed against the outer surface of the housing 7 and closes the bypass holes 11, and the air from the working cavity 5 practically without resistance flows into the cavity 6 of the additional tank 3 through the piston cavity 19, the radial channels 17, the annular cavity 9 and the bypass holes 10, squeezing the elastic element 12 from the outer wall of the housing 7. As a result, the pressure in the cavities 5 and 6 increases almost simultaneously that provides in section I a soft elastic characteristic (figure 2).

In the subsequent course of stretching, the cover 2 with an additional capacity of 3 moves up, and the hollow piston 4 with the piston 14 - down. In this case, the pressure in the working cavity 5 decreases, as a result of which the elastic element 12 is pressed against the outer wall of the housing 7 and closes the bypass holes 10, separating the cavities 5 and 6 at the moment of changing the direction of suspension deformation. As a result, a sharp drop in pressure occurs in the working cavity 5, which ensures a rigid elastic characteristic in section II (Fig. 2).

After the piston 14 passes the middle position at the moment of changing the direction of movement of the sprung mass of the vehicle, the radial channels 16 open and air from the cavity 6 of the additional tank 3 flows practically without resistance into the working cavity 5 through the over-piston cavity 18, the radial channels 16, the annular cavity 9 and the bypass holes 11, squeezing the elastic element 13 from the outer surface of the housing 7. As a result, an almost instantaneous pressure equalization in the cavities 5 and 6 occurs (point 3 in FIG. 2).

With further tension of the suspension, air from the cavity 6 of the additional container 3 flows almost freely into the working cavity 5 through the over-piston cavity 18, the radial channels 16, the annular cavity 9 and the bypass holes 11, squeezing the elastic element 13 from the outer wall of the housing 7. As a result, almost simultaneously a decrease in pressure in the cavities 5 and 6, which provides a soft elastic characteristic in section III (Fig. 2).

In the subsequent compression stroke, the cover 2 with an additional capacity of 3 moves down, and the hollow piston 4 with the piston 14 - up. In this case, the pressure in the working cavity 5 increases, as a result of which the elastic element 13 is pressed against the outer wall of the housing 7 and closes the bypass holes 11, separating the cavities 5 and 6 at the moment of changing the direction of suspension deformation. As a result, there is a sharp increase in pressure in the working cavity 5, which provides a rigid elastic characteristic in section IV (Fig. 2).

After the piston 14 passes the middle position at the moment of changing the direction of movement of the sprung mass of the vehicle, the radial channels 17 open and air from the working cavity 5 flows almost without resistance into the cavity 6 of the additional tank 3 through the piston cavity 19, the radial channels 17, the annular cavity 9 and the bypass holes 10, squeezing the elastic element 12 from the outer surface of the housing 7. As a result, there is an almost instantaneous pressure equalization in the cavities 5 and 6 (point 1 in figure 2).

At the end of the compression stroke, the rubber buffer 20, interacting with the cover 2, is deformed, which prevents a hard blow. In this case, the main load falls on the stiffener 21, which prevents deflection of the upper end of the hollow piston 4.

The proposed air suspension provides self-regulation of inelastic resistance in the direction of relative and absolute oscillations, which leads to an increase in the efficiency of air damping, which results in an improvement in the smoothness of the vehicle.

Claims (1)

An air suspension containing a rubber-cord casing with a lid, forming a working cavity, an additional capacity and a valve device, in which a rod is installed in the form of an elastic rod and a cylinder with a piston, forming a ring cavity with a casing connected to the cavity of the additional capacity and to the cavity of the rubber-cord shell through radial bypass holes closed by elastic elements fixed on the outer surface of the housing, and connected to the cylinder cavity through radial channels, is made in the middle part of the cylinder, which forms a supra-piston and a sub-piston cavity with a piston, characterized in that the valve device is made in the form of a damping assembly, self-regulating in the direction of relative and absolute vibrations, the body of which is placed along the axis of the suspension in the cavity of the additional container rigidly fixed to the cover, the supra-piston cavity is in communication with the cavity of the additional capacity, the sub-piston cavity is in communication with the working cavity, the lower end of the rod is fixed to the upper end of the hollow piston, which is the support th rubber-cord shell, and radial channels are at a distance less than the height of the piston.