RU2646764C2 - Friction shock absorber - Google Patents

Abstract

FIELD: machine engineering.

SUBSTANCE: shock absorber comprises a body (1) formed by its walls (3), a neck (2) and a bottom (4). On the bottom, there is a pre-pressed reciprocating device (5) with a friction unit (7) on its top. The friction unit consists of a pressure wedge (10) and spacer wedges (11) contacting with it. In the neck, there are guide plates (12) in contact with the spacer wedges and with the movable plates (13). The movable plates are placed in contact with the walls and provided with projections. The guide plates are mounted on the inner projections (26) and are provided with friction surfaces (F1 and F2). The friction surfaces are limited in zone from ends of guide plates from side of bottom towards the neck. The movable plates are provided with shanks (32). The width of shank ends is less than the width of movable plate ends at neck forepart.

EFFECT: improved reliability of friction shock-absorber operation.

4 cl, 20 dwg

Description

The invention relates to the field of transport engineering and relates to friction shock absorbers of vehicles, mainly for absorbing devices installed between cars of a train.

Known frictional shock absorber [1, Patent US2701063, IPC B61G 9/10, priority 11/28/1951, publication 02/01/1955], containing wedges placed in the housing, with which plate packets are pinched onto the housing, consisting of a movable plate and guide plates, between which it located, with one of the guide plates in the plate packages located between the housing and the movable plate, and the other between the movable plate and one of the wedges.

Such a friction unit is not very energy-intensive, which is due to the low force of the wedges being formed on the side of its pressure cone against the movable plates and guide plates. The friction forces arising from this are insufficient to achieve high energy absorption. The lack of efficiency is due to the fact that the reciprocating device occupies the space only under the friction unit, and therefore it is impossible to fit springs with great effort into devices with existing dimensions, as a result of which the efficiency of the devices is also low.

This problem is solved in the device [2, SU 253861, IPC B61G 11/16, priority 09/27/1968, published 01/19/1970), adopted as a prototype.

It contains a housing with a neck formed by its walls, as well as with a bottom, on which is arranged with the possibility of its maximum compression, a pre-tensioned reciprocating device, on top of which is a friction assembly consisting of a pressure wedge and spacer wedges in contact with it. In the neck of the housing are mounted on the inner projections of the housing guide plates in contact with spacer wedges and with movable plates, which are located in contact with the walls of the housing.

In order to increase the efficiency of the friction shock absorber [2], protrusions made in contact with the base plate are made on the movable plates. Between such protrusions are guide plates. In this case, each movable plate is supported not by the lower end on the base plate, as in the analogue [1], but by lateral protrusions, which allows to increase the height of the reciprocating device, its rigidity, and the effectiveness of the entire product. In this case, it is not necessary to change its dimensions, the spacer force becomes higher, and the energy absorption in the friction assembly increases. The guide plates are provided with friction surfaces, which are mainly limited in the area determined by the length from the ends of the guide plates from the bottom of the housing to the neck of the housing.

The length of such a zone is less than a third of the total length of the guide plates, therefore, at the end of the full compression stroke with a reciprocating device of high rigidity, an increase in spacer forces occurs, which can often lead to jamming. This is often observed in spring-friction shock absorbers. This effect is observed in all designs of shock absorbers according to the prototype [2], and less often in designs similar to [1], since there in the final position of the friction shock absorber, the spacer wedges fall below the friction surface of the guide plates. Moreover, so that part of the friction surface of the wedges is released from the friction zone. In the final position of the shock absorber according to the prototype [2], the entire friction surface of the wedges remains blocked by the friction surface of the guide plates, or an insignificant part of it is released, about 10% of the total area of the friction surface of the wedge.

Therefore, with the growth of the spacer efforts at the end of the compression stroke of the reciprocating friction shock absorber device according to the prototype [2] between the friction surfaces of its spacer wedges and guide plates, not only does the friction force increase, which are independent of the contact area, but also complex adhesive diffusion processes in the surface layers of rubbing surfaces. Moreover, on a large contact area, “sticking” of spacer wedges on the guide plates occurs.

The above disadvantages of the friction shock absorber of the prototype [2] reduce the reliability of its operation.

Therefore, the objective of the invention is to achieve a technical result aimed at improving the reliability of the friction shock absorber by eliminating the likelihood of jamming of the friction shock absorber during compression of the reciprocating device or during its reverse course, caused by "sticking" of the spacer wedges on the friction surfaces of the guide plates.

The problem is solved in that the friction shock absorber, comprising a housing with a neck formed by its walls, and also with a bottom on which is arranged, with the possibility of its maximum compression, is pre-tensioned reciprocating device, on top of which there is a friction unit consisting of a pressure wedge and spacers in contact with it, in addition, in the neck of the body are guide plates in contact with spacers and movable plates, which are located in contact with the walls of the housing and are provided with protrusions between which the guide plates mounted on the internal protrusions of the housing are located, while the guide plates are provided with friction surfaces, which are mainly limited in the area determined by the length from the ends of the guide plates from the bottom of the housing to the neck of the housing, has a distinctive feature: the length of the zone of restriction of the friction surfaces on the guide plates, more than a third of the total length of the guide plates.

Such a distinguishing feature eliminates the possibility of jamming of the friction shock absorber during compression of its reciprocating device or during its reverse stroke, and also allows the use of a reciprocating retaining device of high rigidity, which will increase the initial tightening force. This will practically eliminate the risk of jamming of elements inside the friction shock absorber, both during compression and during the reverse stroke of its reciprocating device, whether it is a pack of compression springs inserted into each other or a pack of elastic components, which will increase the reliability of the friction shock absorber as a whole . By minimizing the adhesive-diffusion effects at the end of the stroke of the reciprocating device, it makes it possible to install highly elastic structures thereof, which allows:

- achieve high efforts to tighten them;

- limit the excessive increase in shock absorber strength at the end of the stroke;

- receive high energy intensity of the shock absorber;

- provide easy return to its original position.

Additional distinguishing features:

- to enhance the effects mentioned above, it is recommended that the relative position of the friction unit, the movable and guide plates be such that with maximum compression of its reciprocating device, the length of the contact wedges with the guide plates to the mentioned zone of limitation of the friction surfaces would be no more than 80 % length of spacer wedges;

- to prevent the formation of harmful adhesive-diffusion phenomena between the friction surfaces of the mentioned elements of the friction shock absorber, it is recommended to place solid lubricant inserts on the guide plates from the side of the wedges;

- to simplify the design of the middle part of the housing, it is advisable that the guide plates were made with T-shaped limiters of their reverse stroke, which would be located closer to the bottom of the housing behind its internal protrusions;

- to increase the energy intensity of the friction shock absorber, it is recommended that the movable plates in the part closer to the bottom of the body be equipped with shanks whose width of ends would be less than the width of the ends of the movable plates near the beginning of the neck of the body;

- to increase the durability of the walls of the housing, it is recommended that friction liners be installed in the housing between its walls and the movable plates.

The invention is illustrated by illustrations (for a list of reference signs see the graphic part), where in FIG. 1 shows a top view of a friction shock absorber without friction liners in its housing; in FIG. 2-4 show, in various embodiments of the friction shock absorber, its combined profile section AA in FIG. 1, where the friction shock absorber in the initial state is depicted on the left side, and in its fully compressed state on the right side; in FIG. 5 shows a partial cross-sectional view B of FIG. four; in FIG. 6 and 7 show embodiments of a spacer wedge of a friction shock absorber; in FIG. 8 is a cross section of its guide plate, in one embodiment; in FIG. 9 is a view C of FIG. 8; in FIG. 10-14 - other embodiments of the guide plate; in FIG. 15 shows a section through a movable plate of a friction shock absorber in an embodiment with a shank; in FIG. 16 is a view D of FIG. fifteen; in FIG. 17 shows a combined profile section AA of the friction shock absorber of FIG. 1 in the embodiment of its movable plates of FIG. 15, 16, where the friction shock absorber in the initial state is depicted on the left side, and in its fully compressed state on the right side; in FIG. 18 shows a combined profile section AA of the friction shock absorber of FIG. 1 in the embodiment of its guide plates in FIG. 12, where the friction shock absorber in the initial state is depicted on the left side, and in its fully compressed state on the right side; in FIG. 19 shows a top view of a friction damper with friction liners in its housing; FIG. 20 is a combined profile section EE of FIG. 19, where the frictional shock absorber in the initial state is depicted on the left side, and in its fully compressed state on the right side.

The friction shock absorber (Figs. 1-5, 17, 18) contains a housing 1 with a neck 2 formed by its walls 3 and a bottom 4, on which a pre-pressed return-retaining device 5 is located, on top of which directly (not shown) or through a base plate 6 is a friction unit 7.

Reciprocating device 5 can be made in the form of compression springs inserted into each other (not shown) or in the form of a package of elastic-elastic elements 9 resting on washers 8 (Figs. 2, 4, 17, 18).

The friction unit 7 (Figs. 1-4, 17, 18) consists of a pressure wedge 10 and spacer wedges 11 in contact with it. In the neck 2 of the housing 1 there are guide plates 12 which are provided with friction surfaces (Fig. 3), one of which F1 is directed towards the reciprocating device 5, and the other F2 is directed towards the walls 3 of the housing 1. In turn, the guide plates 12 (Figs. 2-5, 17, 18) are located in contact with the said spacer wedges 11 and with movable plates 13, which are located between and in contact with the walls 3 of the housing 1.

To center the reciprocating device 5, the base plate 6 and the pressure wedge 10 in the housing 1 and to fix the friction unit 7, a rod 14 is used, the head 15 of which abuts against the shoulder of the protrusion 16 on the bottom 4 of the housing 1 and, on the other hand, on its threaded part screw nut 17.

To prevent the formation of harmful adhesive-diffusion phenomena between the friction surfaces of the mentioned elements of the friction shock absorber, it is recommended (Fig. 2-4, 8, 9, 11, 17, 18) to place solid lubricant inserts 18 on the guide plates 12 from the spacer wedges 11, for example , from bronze of a special composition. Moreover, the insert 18 on the guide plate 12 is part of its friction surface F1. It is useful to install the same inserts (not shown) between the guides and the movable plates 12, 13, and also, if necessary, between the movable plates 13 and the walls 3 of the housing 1.

Mentioned friction surfaces F1 and F2 (Figs. 2-4, 17, 18) of the guide plates 12 are not located along their entire length Lo. They are mainly limited (Fig. 9-14) in the zone Z1, determined by the length Lz from the ends of the guide plates from the bottom of the housing towards the neck 2 of the housing 1. Moreover, the length Lz of the zone Z1 of the restriction of the friction surfaces F1 and F2 on the guide plates 12 is more than one third 1 / 3 L ₀ total length L _{0 of the} guide plates 12.

The relative position of the friction unit (7), the movable and guide plates 13, 12 is made in such a way that at maximum compression (right halves of figures 2-4, 17, 18) of its reciprocating device 5, when exposed to an external force Q applied to pressure wedge 10, the length of the contacts Lk of the spacer wedges 11 with the guide plates 12 to the aforementioned zone Z1 of the restriction of the friction surfaces F1 and F2 is not more than 80% of the length M of the spacer wedges 11.

It is possible that the friction surfaces F1 and F2 (Fig. 2-4, 17) on the guide plates 12 in the zone Z1 (Fig. 9, 11) their restrictions are completely limited using samples 19, 20 (Fig. 8) in the guide plates 12 along the plane of their friction surfaces F1 and F2.

The movable plates 13 (Fig. 1) are located in contact with the walls 3 of the housing 1 and are provided with protrusions 21 between which the guide plates 12 are located and which, in turn, are located in contact with the protrusions 22 of the base plate 6 (Fig. 2, 17, eighteen).

In the embodiment of the movable plates of FIG. 2 and 3, the guide plates 12 are provided with bends 23, which are located in the windows 24 of the walls 3 of the housing 1.

To simplify the design of the middle part of the housing 1, it is advisable that the guide plates 12 (Fig. 9-14) were made with T-shaped limiters of their reverse stroke, which would be located (Fig. 4, 5, 17, 18) closer to the bottom 4 housing 1 behind its inner protrusions 26.

It is possible that the friction surfaces (F1 and F2) (Fig. 18) on the guide plates 12 in the zone Z1 (Fig. 12-14) their limitations are partially limited by the cavities 27-29 in the guide plates 12 along the plane of their friction surfaces (F1 and F2).

In the design of the friction shock absorber, spacer wedges 11 can be used with different designs of their ends 30 - with a protrusion (Fig. 6) and without it (Fig. 7).

It is also possible that the friction surfaces F1 and F2 (Fig. 18) on the guide plates 12 in the zone Z1 (Fig. 10) their restrictions are partially limited by means of samples 31 on the sides of the guide plates 12.

To increase the energy consumption of the friction shock absorber, it is recommended that the movable plates 13 (Fig. 15, 16) in the part closer to the bottom 4 of the housing 1, be equipped with shanks 32, the width of the ends b2 of which would be less than the width of the ends b1 of the movable plates 13 near the beginning of the neck 2 ( Fig. 17) of the housing 1.

It is useful (Fig. 19, 20) between the walls 3 of the housing 1 and the movable plates 13 to install friction liners 33, based on the support projections 34 of the housing 1. In order to prevent the friction liners 33 from being pulled out of the housing during the shock absorber backward, in the neck 2 of the housing 1 are provided fixing protrusions 35 of the housing 1. Friction liners 33 serve to ensure the abrasion resistance of the walls 3 of the housing 1. Friction liners 33 can be made of heat-treated steels, preventing mutual "sticking" of the moving plates 13 and friction liners 33, while the housing 1 itself can not be subjected to heat treatment, it can be made from cheaper general-purpose steels, and if repair is necessary, not only the entire housing 1 needs to be replaced, but only worn friction liners 33.

Friction liners 33, in justified cases, can be made from other metals or their alloys, ceramic and other materials, which under the given operating conditions of the friction shock absorber are able to provide high reliability and stability of its operation.

The principle of operation of the friction shock absorber is based on the fact that when an external force Q is applied to the pressure wedge 10, for example, from the side of the coupling device when the cars collide, the back-retaining device 5 is compressed (the right parts of FIGS. 2-4, 17, 18, 20 )

In this case, the friction unit 7 operates as follows. The pressure wedge 10 carries the spacer wedges 11 inside the housing 1. At a certain period of the working stroke, the thrust plate (not shown) of the car’s coupler starts to press on the movable plates 13. Under the action of this force, the movable plates 13 with friction along the guide plates 12 and the walls 3 of the housing 1 (Fig. 2-4, 17, 18) or friction liners 33 (Fig. 20) enter the inside of the housing 1. The spacer wedges 11, due to the slope on the guide plates 12, converge inward and to the axis of the shock absorber, sliding along the guide plates 12, as well as friction over the wedges of the pressure wedge 11 and the base plate 6. At the same time, to the very end of the shock absorber’s stroke, the spacer forces increase so much (due to the highly elastic back-retaining device 5) that adhesive-diffusion processes are possible on a large contact area between the spacer wedges 11 and the guide plates 12 leading to "sticking" and possible jamming of the shock absorber, which consists in the inability of the reciprocating device 5 to push out the "stuck" parts of the friction unit 7 and bring the friction shock absorber to and original position. However, in the construction according to the utility model, at the very end of the working stroke, the sample 19 (Fig. 2, 3) on the guide plates 12 from the side of the spacer wedges 11 forms a gap between them, due to which the area of “sticking” is significantly reduced. In addition, such a sample 19 reduces the sharp increase in force, which allows you to use a more rigid reciprocating device with a high tightening force, and, therefore, increase the energy consumption of the shock absorber without the risk of jamming.

When removing the external impact on the shock absorber, the back-retaining device 5 unclenches, pushes the base plate 6 together with the spacer wedges 11 and the pressure wedge 10 installed on it. When passing a certain amount of reverse stroke, the protrusions 22 (Fig. 1) of the base plate 6 capture the protrusions 21 movable plates 13 and the device goes to its original position until it stops the inner part of the pressure wedge 10 in the nut 17.

The use of solid lubricant inserts 18 (Fig. 2, 3), for example, on the guide plates 12 also helps to increase the efficiency and reliability of the shock absorber. The grinding of the particles of the solid lubricant inserts 18 during repeated cycles of external force provides a smooth change in the coefficient of friction of the friction surfaces of the friction shock absorber. At the same time, its working characteristic also becomes smooth, with smaller peaks, and the wear process of the main material of its parts is reduced.

The best version of the friction shock absorber (Fig. 19, 20), when in the process of its cyclic operation, the friction liners 33 are abraded by the moving plates 13, while the walls 3 of the housing 1 are not involved in the friction process.

Information sources

1. Patent US 2701063, IPC B61G 9/10, priority 11/28/1951, publication 02/01/1955.

2. SU 253861, IPC B61G 11/16, priority 09/27/1968, published 01/19/1970 / prototype /.

Claims (4)

1. Friction shock absorber comprising a housing (1) with a neck (2) formed by its walls (3), and also with a bottom (4), on which is located a pre-pressed back-supporting device (5) made with the possibility of its maximum compression, from above of which a friction unit (7) is located, consisting of a pressure wedge (10) and spacer wedges (11) in contact with it, in addition, guide plates (12) are located in the neck (2) of the housing (1) in contact with the spacer wedges (11) ) and with movable plates (13), which are in contact those with walls (3) of the housing (1) and are provided with protrusions (21), between which the guide plates (12) are located, mounted on the inner protrusions (26) of the housing (1), while the guide plates (12) are provided with friction surfaces ( F1 and F2), which are mainly limited in the zone (Z1), determined by the length (Lz) from the ends of the guide plates (12) from the bottom side (4) of the housing (1) to the neck (2) of the housing (1), characterized in that the movable plates (13) in the part closer to the bottom (4) of the housing (1) are equipped with shanks (32), the width (b2) of the ends of which are less he longer ends width (b1) of mobile plates (13) near the beginning of the neck (2) of the housing (1). 2. The shock absorber according to claim 1, characterized in that the friction surfaces (F1 and F2) on the guide plates (12) in the zone (Z1) are partially limited by their cavities (27-29) in the guide plates (12) along the plane their friction surfaces (F1 and F2). 3. The shock absorber according to claim 1, characterized in that the friction surfaces (F1 and F2) on the guide plates (12) in the zone (Z1) are partially limited by means of selections (31) on the sides of the guide plates (12). 4. The shock absorber according to claim 1, characterized in that the guide plates (12) are made with T-shaped restraints (25) of their reverse stroke, which are located closer to the bottom (4) of the housing (1) behind its internal protrusions (26).

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