RU2767801C1 - Hydroelastomeric elastic-damping device of the vehicle suspension system - Google Patents

Abstract

FIELD: transport engineering.

SUBSTANCE: invention relates to transport engineering. The elastic damping device contains a package of elastomeric elements separated by intermediate metal washers. One outer end of the package rests against the washer of the glass, and the other - against the washer of the rubber-metal hinge assembly. The hydraulic telescopic shock absorber is located axially inside the package of elastomeric elements and has a cylindrical closed body and a retractable cylindrical rod. The glass is made in the form of a hollow cylinder with one open and one closed ends, in the plane of which there is a thrust washer. The glass has a node for connection with the sprung parts of the vehicle.

EFFECT: increased reliability and fail-safety of the suspension system, reduced values ​​of unsprung masses of the vehicle suspension, increased smoothness and improved handling and stability.

5 cl, 9 dwg

Description

SUBSTANCE: invention relates to transport engineering, namely to elastic-damping devices of suspension systems.

The design of suspension systems (suspensions) provides for their common work in order to ensure smooth movement and controllability of vehicles. The purpose of elastic-damping suspension devices is to mitigate shocks and shocks when hitting irregularities in the track, damping vibrations (damping) and absorbing shocks and shocks of moving elements (suspension, wheels), as well as the body of the vehicle itself, by converting the mechanical energy of movement (vibrations) into thermal.

Metal elastic elements (springs, springs) and gas-liquid shock absorbers, which act as a damper, are widely used, the masses of which make a significant contribution to the total mass of unsprung parts of the car. An urgent technical problem is to reduce the unsprung masses of the suspension of vehicles in order to improve the performance of smoothness, controllability and stability, therefore, the replacement of metal elastic elements with polymer or composite ones is a promising direction.

Among the composite elastic elements known fiberglass springs (patents US5667206A and EP2971843A1) and helical coil springs (patents US8857801B2, US4260143A, US4765602A). These technical solutions can significantly reduce the value of the unsprung masses of the vehicle suspension, but the production of such elastic elements is very laborious and entails a high cost of the finished product. In addition, these solutions are doubtful from the point of view of reliability, since a single defect in the structure of these composite products leads to the failure of the entire functional unit of the suspension system and can lead to an emergency when the vehicle is moving at high speeds.

Also known analogue of the invention (prototype) where the basis of the elastic and damping suspension device is an elastomeric material (patent RU2596207C2). A feature of this technical solution is the use of a package of elastic elements connected in series and having a guide vane. The invention under consideration makes it possible to provide a progressive elastic characteristic of the suspension, high reliability with a fairly simple and manufacturable design of the product. The disadvantage of the technical solution is the lack of the required damping properties of the device required for most vehicles with medium and high operating speeds. That is why, the use of such a solution is limited to off-road heavy-duty vehicles, where there are no strict requirements for ride comfort, handling, vehicle stability and wheel contact with the supporting surface.

Using the elastomeric elastic elements used in the prototype, and in combination with a hydraulic shock absorber as a suspension damping device and, including the guide vane of the elastomeric elements, it is possible to achieve a reduction in the mass of the elastic damping device, obtaining a progressive elastic suspension characteristic and the required damping characteristic at high speeds rebound and compression of the suspension, which was not done in the prototype. Reducing the mass of the device leads to a decrease in the unsprung mass of the suspension, which, as is known, has a positive effect on the smoothness of the ride, namely, the vibration load of a person and the structure of the vehicle itself is reduced. In addition, a decrease in the value of unsprung masses contributes to a more reliable contact of the wheels with the supporting surface, which qualitatively improves the controllability and stability of vehicles.

Thus, the technical result of using a hydroelastomer elastic-damping device is to increase the reliability and fail-safety of the suspension system, reduce the unsprung masses of the vehicle suspension, increase the smoothness of the ride and improve the handling and stability indicators.

In connection with the above, a device is proposed that performs the functions of an elastic and damping element of the suspension system, and is made in the form of a single product. Such an elastic-damping device has a telescopic hydraulic shock absorber, which performs the main damping function of the product and allows you to absorb and dissipate the energy of suspension deformation, as well as ensure reliable contact of the wheels with the supporting surface. The shock absorber has a body in the form of a cylinder and a retractable rod of the same shape, but of a smaller diameter. In the lower part of the shock absorber housing, an external threaded part is provided for attaching the rubber-metal hinge housing, which is necessary for connecting the device to unsprung parts of the suspension, for example, the lower arm or axle. At the end of the shock absorber rod, a threaded part is also provided for connection with the glass of the product, located coaxially with the shock absorber body.

The shock absorber body is axially located in the central hole of the package of elastomeric elements (elastomers) separated from each other by metal washers, and acts as a guide vane for the elastomers. The centering of the package of elastomer elements along the axis of the shock absorber body is carried out by fluoroplastic rings, which provide a guaranteed gap between the body and the elastomer elements, and also act as sliding supports during compression or tension of the elastomer package. This package performs the elastic function of the device, and partially damping, since the material from which the elastomers are made has internal friction, which contributes to the absorption and dissipation of energy during suspension deformation. The combination of properties of elastomeric elements associated with high specific energy consumption, low density and internal friction makes it possible to create an elastic damping device of low mass, and additionally it becomes possible to reduce the dimensions and weight of the hydraulic shock absorber due to the partial absorption of the suspension deformation energy by the elastomeric package itself.

The package of elastomeric elements rests on the lower washer of the rubber-metal joint housing on one side and on the cup washer on the other side. Since the package is a set of elastomeric elements connected in series, this improves the reliability and fail-safety of the entire product by preventing a complete loss of the elastic function of the device in the presence of damage in one or even several elastomers. In turn, from the point of view of the damping function of the product, there is also a redundancy, carried out due to the fact that in the event of a failure of the hydraulic shock absorber, part of the suspension deformation energy can be extinguished by elastomers.

The glass has the shape of a cylinder with a bottom and a hole for connection with the shock absorber rod. The main function of the glass is to transfer force from the sprung parts of the vehicle (body, frame) to the package of elastomeric elements and the shock absorber rod. The glass has an external threaded part and a stop for connection with a washer that transfers the load to the elastomer package. The inner cylindrical part of the cup has an anti-friction coating in one preferred embodiment or a fluoroplastic insert in the form of a sleeve in another embodiment. This is necessary to ensure wear resistance during free movement of the glass along the axis of the shock absorber with the provision of centering during such movement. In the middle part of the glass there is a section with an external thread for fixing the device with a nut to the sprung part of the vehicle. Fixation is carried out through two rubber buffers, which provide swinging of the axis of the device at small angles when the suspension is deformed. This is necessary to ensure the kinematic requirements for elastic damping suspension devices.

The described design allows the elastic damping device to deform along the shock absorber axis when a load is applied or removed. The displacement of the glass and the shock absorber rod relative to the shock absorber body and the lower rubber-metal hinge is possible due to the volumetric elastic deformation of the elastomeric elements. The compression stroke of the device is limited by the stop of the surface of the bottom of the glass in the end surface of the shock absorber body. The stretching stroke is determined by the design features of the hydraulic shock absorber, in particular, by the presence of a stop on the hidden part of the rod, which abuts against the shock absorber box inside the hydraulic cavity.

Fig. 1 is a front view of a vehicle independent double wishbone suspension incorporating the elastic damping device of the present invention.

Fig. 2 is a left side view of a trailing arm suspension of a vehicle incorporating the elastic damping device of the present invention.

Fig. 3 - the main view of the hydroelastomer elastic-damping device of the vehicle suspension system.

Fig. 4 is a top view of the hydroelastomer elastic damping device.

Fig. 5 is a bottom view of the hydroelastomer elastic-damping device.

Fig. 6 is a longitudinal section of one of the variants of the hydroelastomer resiliently damping device according to the present invention.

FIG. 7 is an enlarged sectional view of the central portion of the hydroelastomer elastic damping device shown in FIG. 6.

Fig. 8 is a graph showing the rebound and compression performance of the hydroelastomer resilient damping device of the present invention.

Fig. 9 is a graph showing the damping characteristic of the hydroelastomer resilient damping device of the present invention.

While the present invention is capable of many variations, preferred embodiments are shown in the drawings and will be described below, it being understood that the present specification provides illustrative examples and does not limit the invention to the embodiments illustrated and described.

Figure 1 shows the first possible installation of the device in the independent suspension of the vehicle on the wishbones. Position 1 denotes an elastic damping device according to the present invention, connecting the group of frame (body) components, denoted by item 2, and the lower suspension arm (item 3). Position 4 indicates the upper suspension arm.

In FIG. 2 shows another possible option for installing the device in the dependent suspension of a vehicle on trailing arms with a drive axle. Position 1 represents the hydroelastomer device according to the present invention, which acts as an elastic and damping apparatus for this type of suspension system. Vehicle frame (item 5), brackets 6 and 7 belong to the group of components of the sprung parts of the vehicle. Trailing arm 8 and drive axle 9 are unsprung parts.

According to the drawings shown in FIG. 3, 4, 5, 6 and 7, in several views of the device, the same parts are indicated by the same reference numbers.

In FIG. 3, 4 and 5 show the appearance of the proposed device according to the present invention. According to these images, the elastic-damping device contains a package of elastomeric elements 10 separated by washers 11, a cup consisting of a body 12, a bottom 13 and a support washer 14, a hydraulic shock absorber, the rod 15 of which is connected to the cup by a nut 16, and the body with a lower hinge assembly, which in turn, it contains a housing 17, a rubber-metal hinge 18 and a support washer 19. Also, to connect the device with the sprung parts of the vehicle, there is an upper hinge assembly, including an upper buffer 20, a lower buffer 21 and a nut 22.

In FIG. 6 and 7 show a longitudinal section and an enlarged sectional view of the central part of one embodiment of the hydroelastomer elastic damping device of the present invention. As shown in FIG. 6, the shock absorber body 23 is located in the central hole of the package of elastomer elements 10, separated from each other by metal washers 11, and additionally performs the function of a guide vane for elastomers. The centering of the package of elastomeric elements along the axis of the shock absorber body is carried out by fluoroplastic rings 24 and 25 (Fig. 7), which provide a guaranteed gap between the body and the elastomeric elements, and also act as sliding supports during compression or tension of the elastomer package. In the embodiment shown, each elastomeric element 10 has an annular or toroidal shape, which contributes to the formation of a progressive elastic characteristic of the device upon deformation. It is sufficient to note that the elastomeric element 10 may preferably be made from a thermoplastic polyester elastomer, or an equivalent known in the art.

A telescopic hydraulic shock absorber, which performs the main damping function, in one of the options may have a steel housing 23, a retractable stainless steel rod 15, a bottom 26, a floating piston 27, preferably made of a bronze alloy or other material with the required antifriction properties, separating the gas and a hydraulic chamber, a steel piston 28 with throttle holes and rebound and compression valves, a stroke limiter 29 with a rubber buffer and a steel or aluminum axle box of the rod 30. connecting the device to unsprung parts of the suspension, such as the lower control arm or axle. At the end of the shock absorber rod 15, a threaded part is also provided for its connection to the steel bottom of the glass 13 of the product by means of a nut 16.

The main function of the glass is to transfer force from the sprung parts of the vehicle (body, frame) to the package of elastomeric elements and the shock absorber rod. Cup body 12 has an external threaded part and a stop for connection with a support washer 14, which transfers the load to the elastomer package. Both parts should preferably be made of steel. The inner cylindrical part of the cup has an anti-friction coating in one preferred embodiment or a PTFE insert 31 in the form of a sleeve in another embodiment. This is necessary to ensure wear resistance and low friction when the body of the cup 12 contacts the body of the shock absorber 23 when the device is compressed or stretched to ensure centering during such movement. In the middle part of the cup body 12 there is a section with an external thread for fixing the device with rubber or elastomer buffers 20, 21 and nuts 22 to the sprung part of the vehicle. Fixation is carried out through two buffers 20 and 21, which are necessary to create several degrees of freedom in conditions of swinging the axis of the device at small angles when the suspension is deformed.

The package of elastomeric elements 10 rests on the lower washer 19 of the housing 17 of the rubber-metal hinge 18 on one side and on the washer 14 of the cup 12 on the other side. When a load occurs on the sprung parts of the vehicle (see Fig. 1 and 2), the force is transmitted through the rubber buffers 20 and 21 to the nut 22 and the cup body 12 (see Fig. 6). The force is transmitted simultaneously to the elastomer package through the washer 14 rigidly fixed on the cup body and to the shock absorber rod 15 by means of the bottom 13 and the nut 16. This causes elastic deformation of the elastomer elements 10, which leads to the cup 12 moving along the device axis relative to the assembly of the lower rubber-metal hinge 18. Damping of suspension oscillations is carried out due to energy losses during the flow of fluid through the channels and valves of the piston 28 of the shock absorber and due to internal friction in the elastomers 10. The compression stroke of the device is limited by the abutment of the surface of the bottom 13 of the glass into the upper end surface of the axle box 30 of the shock absorber. The stretching stroke is determined by the design features of the hydraulic shock absorber, in particular, as shown in FIG. 7 is determined by the distance from the stop 29 to the lower end surface of the axle box 30 of the shock absorber inside the hydraulic cavity.

A view of the elastic characteristic of the suspension when using the device according to the invention under consideration is shown in Fig. 8. Shown here are the experimental curves of compression (loading) and rebound (unloading) of the suspension at low strain rates. It can be argued that the difference between the loading and unloading forces for the same deformation is mainly due to internal friction losses in the elastomeric elements. The average elastic characteristic has a progressive character, that is, there is an increase in the stiffness of the suspension with an increase in the load on the sprung parts of the vehicle. This proves a positive effect on the smoothness of the ride, since the value of the frequency of natural vibrations of the sprung masses will be maintained at different vehicle loads. In turn, it should be noted that obtaining sufficiently energy-intensive devices with high stiffness values and large deformations can be obtained with a relatively small mass of elastomeric elements, which undoubtedly determines the advantage of such types of elastic elements over metal ones (springs, springs, etc.).

In FIG. 9 shows the damping characteristic of the shock absorber obtained experimentally. It makes it possible to prove the necessity of using a hydraulic-type damper for suspension systems of vehicles. This is confirmed by the need to have a rather complex dependence of the damper resistance coefficient at different speeds and directions of suspension deformation. This need is expressed in the required reliable contact of the wheels with the road surface and the damping rate of vibrations when driving at different speeds along different types of road microprofile in order to ensure controllability, stability and smoothness of the vehicle.

In this regard, the use of a combination of light and energy-intensive elastomer materials, combined with proven experience in the operation and production of hydraulic shock absorbers, makes it possible to create high-tech elastic-damping devices for suspension systems with a wide range of characteristics for any type of vehicle.

In connection with the foregoing, it should be noted that numerous modifications and changes can be made without departing from the true and original concept of the present invention. In addition, it should be understood that the purpose of the present description is the presentation of illustrative examples, which are not intended to limit the invention to the specific embodiments shown. On the contrary, the present description includes, by means of the appended claims, all modifications and changes that fall within the spirit and scope of the claims.

Claims (5)

1. Hydroelastomer elastic-damping device of the vehicle suspension system, containing a package of elastomeric elements designed to perform the elastic function of the device and partially absorb the vibration energy of the suspension system, having elastomeric elements, the closed ends of which are directed towards each other and separated by intermediate metal washers, are compressed along the axis of the package within the specified limits, with one outer end of the package abuts against the cup washer, and the other against the washer of the rubber-metal hinge assembly; a hydraulic telescopic shock absorber designed to absorb and dissipate the energy of suspension vibrations, having a cylindrical closed body and a retractable cylindrical rod located axially inside the package of elastomeric elements in such a way that the shock absorber body acts as a guide vane of the package of elastomeric elements; a glass located axially with respect to the package of elements and the shock absorber, having the shape of a hollow cylinder with one open and one closed ends, in the plane of which there is a thrust washer, designed to transfer loads from the sprung parts of the vehicle to the package of elastomeric elements and the shock absorber rod during deformation devices and having a node for connection with sprung parts of the vehicle; a rubber-metal hinge assembly designed to connect the device to the unsprung parts of the vehicle and transfer forces to the package of elastomeric elements through the intermediate washer and to the shock absorber, the body of which is formed by two intersecting cylinders, one of which is axially connected to the lower part of the shock absorber body, the other fixes the hinge in this way that the axis of the hinge is perpendicular to the axis of the package of elements and the shock absorber. 2. Hydroelastomer elastic-damping device according to claim 1, characterized in that said shock absorber has a single-tube design. 3. Hydroelastomer elastic-damping device according to claim 1, characterized in that said shock absorber has a two-pipe design. 4. Hydroelastomer resilient damping device according to claim 1, characterized in that said cup contains a device fastening unit to sprung parts of the vehicle with elastic rubber or elastomeric buffers, located axially with the cup axis. 5. Hydroelastomer resilient damping device according to claim 1, characterized in that the said glass contains a device fastening unit to the sprung parts of the vehicle with a rubber-metal hinge, the axis of which is perpendicular to the axis of the glass.

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