DE2256201A1 - DAMPING DEVICE OR SHOCK ABSORBER - Google Patents

Description

Paienicmwcäte Dr.-lng. Wilhelm Reichel Dipl.-Ing. Woligang Beichel

6 Frankfurt a. M. 1

Parksiraßel 3

THE YOKOHAMA RUBBER CO., LTD., Tokyo, Japan Damping device or shock absorber

The invention relates to a damping device or a shock absorber with a cylinder, one between one first and second position movable piston and a chamber, the volume of which is variable in the cylinder, wherein the one Wall of this chamber is formed by the piston. Further, the invention is directed to improvements in a shock absorber of the type directed, which has a cylinder into which a. dilatable or expandable material is filled in, while a piston is fitted or inserted in the cylinder.

By the term "dilatable material" as used below, a macromolecular, flowable viscous body is understood which has a dilating property such that it is flowable or flowing in the form of a liquid when it is under a progressive external force that but does it lose this fluidity and change into a solid state _? when he is under a sudden external force. Furthermore, when an additional force is exerted on this body, it fiddles a dynamic one

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Phenomenon similar to a pushing or shearing force, whereby he consumed a large amount of energy. The speed-dependent dynamic properties of the dilatable material are shown in Fig. 3, in which no deformation or deformation resistance occurs with a slow deformation, whereas a large deformation or deformation resistance shows itself at a high deformation speed. These Properties are ideal from the standpoint of the function of a cushioning device or a shock absorber. With In other words, during the impact movement of a piston in which a sudden force is exerted on the piston, due to Due to the greater resistance to deformation, a large amount of energy can be absorbed and vice versa during the return stroke or the return movement, during which the external force has been canceled, the dilatable material is restored to its original state return flowable state, which enables the shock absorber to be restored with a small force can be returned to its original state. Furthermore, the change in the properties of this material is similar a reversible phase change b2w. repeatable, such that even after repeated use no change in the Properties of the dilatable material occurs, so that practically a permanent, reliable use is guaranteed is.

However, if such a dilatable material is used in an application where it is completely a Is subjected to compressive force, because of the construction that contains this material, so causes an increase in the displacement as shown in Fig. 4 by curve c, which illustrates the ratio of load to deformation, increased exposure, combined with lower energy absorption and thus a lower damping performance. .

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In a 'conventional shock absorber of this type, as follows will be explained in detail, the dilatable material in a cylinder on the damping * Moving side of a piston deflates while the air is on the return stroke side of the piston is inserted into the cylinder. During the cushioning stroke of the piston, the Dilatable material from the damping stroke side to the return stroke side of the piston so that there is no pressure or pressure on this material as a result of the penetration of the piston into the cylinder Compression force is exerted, r

However, such a conventional shock absorber still has the disadvantage that the air trapped in this way tends to has to escape into the dilatable material, which leads to a delayed response to the impact force, which is exerted on the piston rod.

The present invention is therefore based on the object To create a shock absorber of the type in which a dilatable or expandable material is incorporated into a Cylinder is filled into which a piston is fitted or inserted is, wherein the shock absorber should be designed in such a way that an air inclusion in the dilatable material is excluded can be so that. it responds directly to the impact force exerted on the piston,

According to the invention, this object is achieved in that the chamber is filled with a dilatable material, when the piston is in the first position that a channel is led away from the chamber so that when the piston ■ moved towards the second position, the shock load transmitted by the piston is absorbed by the dilatable material and the chamber volume decreases, which has the consequence that the dilatable material in the chamber is pressed out through the channel, that a device for receiving the dilatation

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capable material are completely sealed and substantially so airtight that the air is prevented from the Contact dilatable material.

Thus, in accordance with the present invention, there is provided a shock absorber of a construction that includes a Has cylinder into which a dilatable material is filled and a piston is slidably seated, with the energy an impact load is transmitted through the piston and is absorbed by means of the dilatable material. The invention is further characterized in that the shock absorber additionally has a chamber, the internal volume of which is dependent can change from the internal pressure within the cylinder, wherein the chamber is in communication with the cylinder via a channel, such that when the piston moves within the cylinder due to an impact load, the dilatable material in the cylinder absorbs a large amount of the loss energy due to the high rate of deformation while the material thereby pulverized at the same time and injected or pressed through this channel into the interior of the chamber will.

Further refinements of the invention emerge from the subclaims emerged.

The invention will now be described in detail with reference to the accompanying figures described, with all details or features emerging from the description and the figures for the solution can contribute to the task within the meaning of the invention and were included in the application with the intention of being patented. Show it:

Figures 1 and 2 are longitudinal sectional views of conventional shock absorbers;

Fig. 3 is a diagram in which the deformation or VerformuniTS-

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The speed of the dilatable material is recorded against the resistance to deformation is;

Fig. 4 is another graph with characteristic curves illustrating the damping performance;

Fig. 5 is a longitudinal section of a first embodiment of the present invention;

6 shows a longitudinal section of a second embodiment of the invention;

7 and 8 are longitudinal sectional views of a third embodiment of the invention, the former showing the shock absorber in the unloaded state and the latter

shows the shock absorber in a loaded condition.

Description of the Preferred Embodiments

Before describing the preferred embodiments of the invention in detail, a shock absorber becomes more conventional Design with reference to the drawings for a better understanding of the present invention explained.

1 shows that a piston 2 is inserted loosely into a cylinder 1. The dilatable material is in the Cylinder 1 is introduced on the damping stroke side of the piston 2, while the air 4 is in the cylinder on the return stroke side of the piston 2 is located. During the damping stroke, the dilatable material is consequently removed from the damping stroke side pressed into the return stroke side in such a way that it is prevented that the dilatable material due to the penetration of a piston

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rod 5 is pressed together.

However, this has the consequence that during the return stroke Piston 2 part of the air 4 in the damping or compression stroke side of the piston together with the dilatable Material is introduced, as a result of which air inclusions or a foam structure 4a are generated, as indicated in FIG. 2 is.

As a result, during the subsequent cycle of a damping process the displacement of the piston 2, as shown with the aid of the characteristic curve in FIG. 4, does not have any direct impact exercise the dilatable material due to the compression of the air pockets 4a, so that an additional Displacement or adjustment of the piston becomes necessary, which, however, leads to a delayed response to the shock.

Reference is now made to FIG. 5, in which the first embodiment of the present invention is shown. With the reference number 10 a cylinder is identified, with 11 a Piston which is slidably inserted in the cylinder 10, and with 12 a piston rod. The piston 11 and the piston rod 12 consist of a hollow construction, the open end of the piston 11 being closed by a closure piece 14 which contains an opening 13 with a small cross-sectional area and is removable or detachable at this open end is attached. A movable plate is marked with 15 " which is axially displaceable in the piston 11 and also in the piston rod 12. A coil spring 16 is movable between the Plate 15 and the bottom of the piston rod 12 clamped and presses the movable plate 15 against the closure piece Reference number 17 denotes a chamber containing a dilatable material, i.e. a macromolecular flowable viscous Contains body, e.g. a silicon-based spring filler. An air chamber 18 is through a hole 19 with the Atmosphere in communication. An O-ring 20 is around the

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The outer circumference of the piston 11 is attached and serves as a seal that ensures the air tightness between the dilatable Material..containing chamber 17 and the atmosphere is maintained. An O-ring 21 is attached around the outer circumference of the movable plate 1 * 5 to ensure an airtight relationship between the chamber 17 containing the dilatable material and the air chamber 18 to be maintained. At 22 there is a locking ring which is attached to the open end of the cylinder 10 and retains the piston in the cylinder 10 or backs up. In one piece with the cylinder 10, an eyelet 23a is formed, while an eyelet 23b is integral with the Piston rod 12 is connected.

If, during operation, an impact force is exerted from the left on the eyelet 23b according to FIG. 5, while the eyelet 23a is stationary is held, the piston 11 is suddenly moved to the left. pushed, which has the consequence that the dilatable material in the chamber 17 is subjected to a "shear destruction" due to the high rate of deformation, resulting in his Pulverization leads. At the same time, the dilatable material pulverized in this way is replaced by a Opening 13 is pressed into the cavity of the piston rod 12. This process causes the absorption of a large amount of energy, namely by converting the impact energy ... into a shear destruction energy, while at the same time a part is converted into frictional heat due to the friction under the Particles of the dilatable material. When the piston rod 12 penetrates the cylinder 10, it will do so in the chamber 17 enclosed dilatable material is pressed through the opening 13 into the space on the right side of the closure piece 14 is present, whereby the movable plate 15 is biased to the right against the spring action of the spring 16 will. This means that there is only a minimal amount of dilatable material itself during the cycle described above

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Pressure or compression force is subjected. In this way one achieves the high energy absorption that is achieved by the characteristic curve a is shown in FIG. So lets the high damping performance can also be achieved. When the energy absorption has ended, the movable one moves Plate 15 slowly moves under the return force of spring 16 left, so that the dilatable material in the piston rod is in a flowable state through the opening 13 into the interior of the cylinder 10, causing the piston 11 to return to the original position. In this context it should be noted that the chamber 17 containing the dilatable material and the air chamber 18 are formed by the O-ring 21 are kept in an airtight relationship with each other fixed on the movable plate 15, thereby preventing the escape of air, which is located in the air chamber 18, is prevented from entering the dilatable material. This causes the Exceptionally good response properties during the damping stroke. In addition, the dilatable material is well suited for repeated use or repeated use.

The results of experiments show that a compressive force of 5 tons was developed in a cylinder having an inner diameter of 22 mm and that a damping performance of 93 % was achieved. In addition, constant energy absorption was achieved even after 3,000 damping cycles.

Reference is now made to Fig. 6 which shows the second embodiment of the invention shows. With the reference numeral 30, a cylinder is identified, with 31 a piston, which is in the Cylinder 30 is slidably seated, with 32 openings are designated, which extend radially through the wall of the cylinder 30 and with 33 a cylindrical sleeve which expand and can contract, is made of an elastomer and is fixed around the cylinder 30 so that it is the Openings 32 covers. The opposing circumferential

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The edges of this cuff are airtight on the outer circumference of the Cylinder 30 attached, as shown in the drawing. A chamber 35 contains a dilatable material and an O-ring 36 that goes around the outer circumference of a piston is attached, ensures the airtightness between the chamber 35 containing the dilatable material and the The atmosphere. A guide groove is provided alongside in the outer wall of the piston 31 and takes the tip of a screw 38, which is screwed into the outer wall of the cylinder 30, for the purpose of holding the piston within the cylinder, while at the same time preventing rotational movement of the piston relative to the cylinder. An eyelet 39a is made in one piece with the cylinder 30, while an eyelet 39b is formed integrally with the piston 31.

When the piston 31 is in its extended or rest position which is shown in Fig. 6, the collar 33 will normally lie flat against the outer wall of the cylinder 30 so that no air is in contact with the dilatable material in the chamber 35. However, to show more clearly how the cuff 33 operates is shown in FIG. 6 in a partially expanded position, which is normally is not reached until the piston 31 has been moved to the left.

If during operation an impact force on the eyelet 39b according to FIG is exercised to the left while the eyelet 39a is held stationary, then the piston 31 is suddenly to the left moves, with the result that the dilatable material in the chamber 35 due to the high rate of deformation is subjected to a seer's destruction leading to its pulverization leads. At the same time, the dilatable material pulverized in this way is passed through the openings 32 into the cuff 33 pressed in or injected, while it is the ejected

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exerted a resistance against the shock. The cuff 33 is then expanded as the piston 31 penetrates further into the cylinder 30, the internal volume of the chamber 35 correspondingly is decreased. The dilatable material injected or squeezed out in this way is consequently in no way subjected to high pressure or compression force. In this case too, the characteristic curve a shown in Fig. 4 energy absorption, associated with a high damping performance.

When the impact energy has been fully absorbed and no longer a force exerted on the piston 31 from the left then the cuff can contract due to its elasticity, with the dilatable material under it Pressure sets so that this is in a liquid state through the openings 32 flows into the cylinder 30. This has the consequence that the piston 31 moves to the right into its starting position. In other words, the cuff is expanded to a volume corresponding to that part of the piston '31 shown in the cylinder 30 is introduced, this very low pressure or compression force on the dilatable material is exercised. Test results showed a damping effect or a damping performance of up to 85%.

Reference is now made to Figures 7 and 8 which show the third embodiment of the invention. The reference number 40 denotes a cylinder, 41 a piston which is slidably seated in the cylinder 40, but at a certain distance or with a certain clearance 42 from the inner wall of the cylinder. Finally, the reference number 43 denotes a piston rod, which extends through a hole in a closure 44 to the outside. The locking piece 44 is in the open end of the Cylinder 40 releasably attached. A compression spring 45 is clamped between the closure piece 44 and a flange part 43 'of the piston rod 43. A movable ring 46 is through the Action of a spring 47 pressed against the piston 41. One

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Chamber 48 contains the dilatable material, while 49 is an air chamber. An O-ring 50 is attached around the outer circumference of the movable ring 46. An O-ring 51 is on the inner circumference of the movable ring 46 appropriate. The O-rings 50 and 51 thus together form one airtight seal between the chamber 48 containing the dilatable material and the air chamber 49 »A ventilation opening 52 is provided in the closure piece 44. An eyelet 53a is rigidly attached to the cylinder 40, while a The eyelet 53b is made in one piece with the piston rod 43.

When in operation, as shown in FIG. 7, an impact force is exerted from the left as shown in FIG. 7 on the eyelet 53b, while the Eye 53a is held stationary, the piston 41 is suddenly shifted to the left, with the result that the dilatable material in the chamber 48 is subjected to shear destruction due to the high rate of deformation leads to its pulverization. At the same time, the material pulverized in this way becomes dilatable through the clearance 42, which is provided between the inner circumference of the cylinder 40 and the outer circumference of the piston 41, against the right Side of the piston 41 injected or printed, where it absorbs the impact energy. At this point, as in ' Fig. 8 shows the movable ring 46 against the force of the spring 47 through the injected dilatable material pressed to the right in a position in which the volume of the dilatable material that is injected on this V / eise is equal to the volume of the piston rod 43 inserted into the cylinder 40. This means that the dilatable Material itself is subjected to only a very weak compressive or compressive force, while it is its large one Shows energy absorption property associated with a high damping effect.

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After the energy has been completely absorbed, the piston 41 and the piston rod 43 are under the influence of the Compression spring 45 moved to the right, with the internal pressure on the dilatable material enclosed in the chamber 48 is lowered so that the movable ring 46 is under the influence the force of the spring 47 in the air chamber 49 returns to its original position. In this connection it should be noted that the complete airtightness between the chamber 48 containing the dilatable material and the air chamber 49 prevents air from entering or escaping into the dilatable material. This gives a high energy absorption property as well as a high damping performance for repeated many work cycles.

As can be seen from the above, the present invention provides a shock absorber or dampening device that uses dilatable material. This shock absorber includes one Cylinder in which the dilatable material is filled, as well as a piston which is slidably seated in the cylinder, wherein the energy of the shock load transmitted through the piston by means of the dilatable material is absorbed. This shock absorber is characterized in that it also has a chamber, the interior of which Volume changes as a function of the internal pressure in the cylinder, with the chamber via a channel with the Cylinder is in communication. Accordingly, when the piston moves in the cylinder due to an impact load, it is absorbed the dilatable material in this cylinder generates a large amount of destructive energy due to the high degree of deformation is generated while the material is being pulverized, followed by injection through the channel into the Interior of the chamber follows. At this point, the impact energy is converted into frictional heat, which leads to friction

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which is predominant among the particles in the dilatable material. However, the pressure exerted by the dilatable material that is injected in powder form expands or changes the internal volume of this chamber such that the dilatable material in the cylinder is subjected to very little pressure or compression force due to the change in the internal volume of the cylinder as the piston moves into it. It should be noted that, in contrast to a conventional shock absorber, there is no risk of air inclusions getting into the dilatable material during the return stroke of the piston, whereby a constant high damping performance is achieved regardless of repeated use of the shock absorber.

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Claims (21)

Claims Shock absorber with a cylinder, a piston, which is slidable between a first and second position is and a chamber, the volume of which is variable in the cylinder, wherein the one wall of the chamber through the piston is formed, characterized in that the chamber (17, 35, 48) with a dilatable Material is filled when the piston (11, 31 »41) is in the first position that a Channel (i3, 32, 42) is led away from the chamber in such a way that when the piston moves towards the second position, the shock load transmitted by the piston is absorbed by the dilatable material and the chamber volume decreases, with the result that the dilatable material in the chamber passes through the channel is pressed out that a device (12, 33, 4o) is provided for receiving the dilatable material, which is pressed out of the chamber (17, 35, 48) that a device is provided that the piston against the first position presses and that the chamber and the device for receiving the dilatable material are completely sealed and substantially airtight to such an extent that air is prevented from entering the Contact dilatable material. 2. Shock absorber according to claim 1. characterized in that the device (12, 40) for receiving the dilatable Material is arranged on the side of the piston (11, 41) which is opposite to the chamber (17, 48) lies. 309825/0306 3. Shock absorber according to claim 2, characterized in that that a hollow piston rod (12) with the piston (11) connected, and the device for receiving the dilatable material in the piston rod (12) is arranged. 4. Shock absorber according to claim 3 »characterized in that that the channel (13) from an opening in the part (14) of the piston (11) which forms a wall of the chamber (17). 5. Shock absorber according to claim 4, characterized in that a plate (15) is displaceable in the piston rod (12) is arranged that the plate (15) rests against the piston (11, 14) when the piston is in the first position is so that when the piston moves to the second position, the dilatable Material is squeezed out through the channel (13) and between the plate (15) and the part (14) of the piston (11) which forms a wall of the chamber (17). 6. Shock absorber according to claim 5, characterized in that that it contains a spring arrangement (16) which presses the piston (11) into the first position. 309825/0306 7. Shock absorber according to claim 6, characterized in that that the spring arrangement (16) between the plate (15) and part of the piston rod (12) is switched on. 8. Shock absorber according to claim 5, characterized in that the plate (15) around its outer circumference with a groove is provided that an O-ring (21) in this Groove is arranged, and that the O-ring (21) in contact with the inside of the piston rod (12) stands that between the plate (15) and the piston rod (12) a substantially airtight seal is formed. 9. Shock absorber according to claim 1, characterized in that that the piston (11) is provided with a groove around its outer circumference, that an O-ring (20) in this groove is arranged and that the O-ring (20) is in contact with the inside of the cylinder (10) so that between a substantially airtight seal is formed between the piston 11 and the cylinder (10). 10. Shock absorber according to claim 2, characterized in that the device for receiving the dilatable Material is arranged in the cylinder (40). 11. Shock absorber according to claim 10, characterized in that the channel (42) consists of a space between the circumference of the piston (41) and the inside of the cylinder (40). 309825/0306 12. Shock absorber according to claim 10,
characterized in that a piston rod (43) is connected to the piston (41) and the piston rod protrudes from the cylinder (40). 13. Shock absorber according to claim 12,
characterized, that a plate (46) is slidable in the cylinder (40) is arranged that the piston rod (43) extends through this plate, that the plate (46) abuts the piston (41) when the piston is in the first position so that when the piston is moved into the second position, dilatable material through the channel (42) between the Plate (46) and the piston (41) is pressed. 14. Shock absorber according to claim 13,
characterized, that it contains a further spring arrangement (45) which pushes the piston (41) into the first position. 15. Shock absorber according to claim 13,
characterized in that it further includes a spring assembly (47) urging the plate (46) against the piston (41). 16. Shock absorber according to claim 13,
characterized, that the plate (46) is provided with a groove on its outer circumference and on its inner surface, that O-rings (50, 51) are arranged in these grooves and that the O-rings (50, 51) are in contact with the inside of the Cylinder (40) and the piston rod (43) are so that between the plate (46), the cylinder (40) und.der Rod (43) provides a substantially airtight seal 309825/030 6 is trained. 17. Shock absorber according to claim 1, characterized in that the device (33) for receiving the dilatable Material is arranged outside of the cylinder (30). 18. Shock absorber according to claim 17, characterized in that that the channel contains a number of openings (32), extending through the wall of the cylinder (30). 19. Shock absorber according to claim 18, characterized in that that the device for receiving the dilatable material and the device for pressing and holding includes a cuff (33) made of a contractible and expandable material is. 20. Shock absorber according to claim 19, characterized in that the sleeve (33) attached to the cylinder (30) is. 21. Shock absorber according to claim 20, characterized in that the sleeve (33) comprises the cylinder (30). ReFu / Pi. 309825/0306 Lee r side