EP1283958B1 - Pneumatic cylinder with damping in the end position - Google Patents

Abstract

A pneumatic cylinder with damping in the end position, also comprising a housing in which at least one slide rod element is mounted with at least one sealing element, in such a way that said slide rod element is linearly displaceable. At least one damper sleeve or its bearing arrangement is associated with the slide rod element, said bearing arrangement engaging with front-end bearing elements in the end positions. According to the invention, the damper sleeve or its bearing arrangement has at least one indentation for damping the end position and for ventilation.

Description

The present invention relates to a pneumatic cylinder with cushioning with a housing in which at least one push rod element with at least one sealing element is mounted linearly movable, wherein the push rod element is associated with at least one damper sleeve, which engages in the end positions in frontal bearing elements, and a damper sleeve or its storage.

Such pneumatic cylinders are known in vielfälltigster form and execution in the market and in use. They are essentially used to move any objects and are commonly used in handling today.

Within a housing, a push rod element is movable in the manner of a piston, the push rod element being supported in a reciprocating manner via end bearing elements.

Nowadays ever higher demands are placed on such pneumatic cylinders. They are constantly operated faster, with higher forces and loads must be absorbed.

Here, in particular, a cushioning problematic because so far in the frontal bearing elements throttle valves or the like. Are used to dampen the corresponding end positions when the push rod element, in particular its damper sleeve enters into a corresponding bearing of the bearing elements.

Furthermore, it is disadvantageous that in conventional throttles or throttle valves, in particular in the case of large mass differences which rest on the push rod element of a pneumatic cylinder, vibrations occur in the end position range. Furthermore, conventional cylinders can only be used to a very limited extent, which relates in particular to the absorption of loads of different sizes and also to high speeds and / or accelerations.

For end cushioning conventional chokes must be permanently and tediously re-adjusted very costly in permanent operation of the pneumatic cylinder. Even with the first installation of such a pneumatic cylinder in a machine or system a lengthy adjustment of the end positions is required. For this purpose, only qualified personnel can make a corresponding adjustment of the end positions.

In addition, corresponding additional throttle holes, throttle inserts and throttle channels cause higher manufacturing costs, which is undesirable.

GB 2 049 050 describes a hydraulically operated cylinder in which a piston is reciprocated by means of a liquid working medium. A corresponding damper sleeve has a slot for cushioning.

The present invention has for its object to provide a pneumatic cylinder of the type mentioned, with which the disadvantages mentioned are eliminated and with which in particular a cushioning should be substantially improved, with additional manufacturing costs omitted and a readjustment by costly specialist staff should be eliminated. In addition, higher cycle times should be possible with the same end position damping. A first installation and an immediate operation should be possible without specialist personnel and without adjusting an end position.

To achieve this object, the features of claims 1 and 8 lead.

In the present invention, a notch is preferably provided in an outer circumferential surface of a damper sleeve or in an inner circumferential surface of a bearing of the damper sleeve, which extends in the axial direction of the bearing or the damper sleeve.

About this notch can throttle-like relax the end of the built-up pressure in the housing interior. As a result, a movement of the push rod element is damped in the end position.

It has proved to be particularly advantageous to provide the notch discontinuously in the lateral surface of the damper sleeve or in their storage.

At one end, near a phase of the damper sleeve, the notch is formed deeper than at its other end, where it almost overflows into the lateral surface and runs into it. The same applies to the storage, should be provided in the storage, the notch.

Thus, an expansion of the air or the gas is continuously reduced by the decreasing cross-section of the notch, which also promotes a braking movement in the increasing Endlagenbereich more and more.

In this case, the notch triangular, square, curved or cross-sectionally shaped differently.

Furthermore, it is also thought to assign a plurality of notches either the damper sleeve in the shell surface, or provide in an inner circumferential surface of the storage of damper sleeves. Here is the invention no limit set. Preferably, the notches are provided axially and linearly parallel to the push rod or parallel to the push rod member. However, these can also be provided, for example, diagonally or serpentine in the lateral surface in the longitudinal direction. However, the present invention should not be limited thereto.

In a further embodiment of the present invention, in addition to a pneumatic cylinder, in particular in its bearing elements, a pressure relief valve is provided, which via an overpressure channel with a Compression space, which is formed between the sealing element, damper sleeve, inner circumferential surface of the housing and an end face of the bearing elements, is in communication. By the rapid acceleration or movement of the push rod element against the end face of the bearing element, a pressure is increased, which can expand in the manner described above on the at least one notch in a cavity of the bearing element, however, to prevent vibrations, especially in Endlagendämpfen, can be Relieve emerging pressure peaks via at least one pressure relief valve, which is preferably by means of a bypass with an environment or a cavity of the bearing elements in combination. Only the pressure peaks are damped, in which the pressure relief valve is preferably opened for a short time.

However, it should also be within the scope of the present invention to use a conventional damper sleeve to dampen the end position by means of a corresponding pressure relief valve. Therefore, two protection is sought separately by the sibling claim. As a result, very large mass differences can be moved with one and the same pneumatic cylinder, wherein an end position damping is optimized without vibrations occurring during the end position damping. Furthermore, very high speeds or accelerations of the push rod element with subsequent load can be realized. In addition, it is advantageous that no adjustment, even with different masses, which rest on one and the same pneumatic cylinder, is required. In particular, a large mass difference of, for example, 5 to 60 kg can be moved with one and the same cylinder via the corresponding pressure relief valve, even at very high and low temperatures changing speeds or accelerations. The pressure relief valve damps the vibrations completely in the end positions.

• Figur 1 eine schematisch dargestellte Draufsicht auf einen Pneumatikzylinder mit eingesetztem Schubstangenelement;
• Figur 2 eine schematisch dargestellte Draufsicht auf ein Schubstangenelement mit zwei Dämpferhülsen und dazwischen gelagerten Dichtelementen sowie einen Teillängsschnitt durch ein Lagerelement mit Lagerung zur Aufnahme der Dämpfungshülse;
• Figur 3 einen Längsschnitt durch eine erfindungsgemässe Dämpferhülse;
• Figur 4 eine Seitenansicht auf die Dämpferhülse gemäss Figur 3;
• Figur 5 einen Längsschnitt durch ein weiteres Ausführungsbeispiel der Dämpferhülse gemäss Figur 3;
• Figur 6 eine Seitenansicht der Dämpferhülse gemäss Figur 5;
• Figuren 7a und 7b schematisch dargestellte Seitenansichten auf eine Dämpferhülse mit erfindungsgemässer Einkerbung;
• Figuren 8a und 8b Seitenansichten auf die Dämpferhülse gemäss den Figuren 3, 5 sowie 7a als weitere Ausführungsbeispiele mit erfindungsgemässer Einkerbung;
• Figur 9 einen schematisch dargestellten Längsschnitt durch die Dämpferhülse gemäss Figur 7a entlang Linie IX-IX;
• Figur 10 eine schematisch dargestellte Draufsicht auf eine mögliche weitere Anordnung der Einkerbung in einer Mantelfläche einer Dämpferhülse;
• Figur 11 einen schematisch dargestellten Längsschnitt durch ein weiteres Ausführungsbeispiel der Dämpferhülse;
• Figur 12 eine Seitenansicht auf die Dämpferhülse gemäss Figur 11;
• Figur 13 eine schematisch dargestellte Draufsicht auf das weitere Ausführungsbeispiel der Dämpferhülse gemäss den Figuren 11 und 12;
• Figur 14 einen schematisch dargestellten Teillängsschnitt durch ein weiteres Ausführungsbeispiel eines Pneumatikzylinders gemäss Figur 1.

Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments and from the drawing; this shows in

• Figure 1 is a schematic plan view of a pneumatic cylinder with inserted push rod element;
• Figure 2 is a schematic plan view of a push rod element with two damper sleeves and sealing elements mounted therebetween and a partial longitudinal section through a bearing element with storage for receiving the damping sleeve;
• 3 shows a longitudinal section through an inventive damper sleeve.
• Figure 4 is a side view of the damper sleeve according to Figure 3;
• 5 shows a longitudinal section through a further embodiment of the damper sleeve according to Figure 3;
• Figure 6 is a side view of the damper sleeve according to Figure 5;
• Figures 7a and 7b schematically shown side views of a damper sleeve with notch according to the invention;
• Figures 8a and 8b are side views of the damper sleeve according to Figures 3, 5 and 7a as further embodiments with inventive notch;
• 9 shows a longitudinal section through the damper sleeve according to FIG. 7a along line IX-IX, shown schematically; FIG.
• FIG. 10 shows a schematically illustrated plan view of a possible further arrangement of the notch in a lateral surface of a damper sleeve;
• Figure 11 is a schematically illustrated longitudinal section through a further embodiment of the damper sleeve;
• Figure 12 is a side view of the damper sleeve according to Figure 11;
• Figure 13 is a schematic plan view of the further embodiment of the damper sleeve according to Figures 11 and 12;
• 14 shows a schematically illustrated partial longitudinal section through a further exemplary embodiment of a pneumatic cylinder according to FIG. 1.

According to FIG. 1, a pneumatic cylinder R has a housing 1, which is designed like a cylinder in the interior. On the end of the housing 1 each include bearing elements 2.1, 2.2, on the one hand act on an internal push rod element 3 to reciprocate any loads with pressure and control accordingly.

In this case, corresponding openings 4.1, 4.2 are provided in the bearing elements 2.1, 2.2, which form the corresponding connections for the pneumatic lines, not shown here for supplying air or gas into the housing interior of the housing 1.

If air is introduced into the housing 1 through the opening 4.1 via the bearing element 2.1, then the push rod element 3 can be moved in the direction of the bearing element 2.2. If, however, air or gas is introduced via the opening 4.2 in the housing 1, the push rod element 3 can move back.

For end cushioning od in the bearing elements 2.1, 2.2 od. Like. Provided, in which corresponding, the push rod member 3 associated damper sleeves 5, as they are, for example. In Figure 2 shown, intervene. Between the two damper sleeves 5, at least one sealing element 6 is provided which extends like a piston inside the cylindrical housing 1 and the push rod element 3 on the one hand superimposed and on the other hand seals.

The diameter of the damper sleeve 5 are slightly larger than that of the push rod 7 of the push rod element. 3

The damper sleeves 5 engage in the corresponding bearing elements 2.1, 2.2, in particular sealed in their storage 13, wherein the opening 4 is closed. Conventionally, via a throttle, a throttle valve od. Like. The compressed air for damping a pushing movement of the push rod element 3 in an end position continuously and slowly dissipated.

In the present invention, however, can be dispensed with corresponding throttle elements, in accordance with the invention, the damper sleeve 5 or its storage 13 at least one notch 8 is provided in the lateral surfaces 9.

As shown in particular in Figure 2, the notch 8 is linear and parallel to the push rod 7 in a longitudinal direction of the damper sleeve 5 is provided.

If the push rod element 3, in particular the damper sleeve 5 in the corresponding seal of the bearing elements 2.1 or 2.2 or in the bearing 13 in the respective end positions, so the Endlagendämpfung the movement of the push rod element 3, the compressed air in the bearing element 2.1 or 2.2 or in the Storage 13 via the notch 8 continuously, permanently and slowly escape.

At one end, the damper sleeve 5 is provided with a phase 10, which serves for insertion into the bearing 13 of the bearing elements 2.1, 2.2.

In the figures 3 and 5 respectively longitudinal sections of the damper sleeve are shown, in which the notch 8 can be seen. In the embodiment of Figures 3 and 4 and 5 and 6, the notch 8 is formed cross-sectionally triangular.

In this case, the notch 8 in the region of an end face 11 is inserted substantially deeper starting from the lateral surface 9 and, viewed in the direction of the lateral surface 9, terminating, is formed to the opposite end face 12. In the region of the end face 12, in particular in the lateral surface 9, the notch 8 is very small or almost merges into the lateral surface 9.

As a result, a cross-sectional area of the notch 8 changes permanently, whereby, starting from the end face 11, this cross-sectional area tapers in the direction of the end face 12.

Furthermore, it should also be within the scope of the present invention, as is indicated, for example, in FIG. 2, that a bearing 13 of the bearing elements 2.1 or 2.2 can be provided in the region of an inner lateral surface 9 of the indentation 8 described above. Then, for example, a sealing ring would be provided on the damper sleeve 5, so that over the notch 8 in the inner circumferential surface 9 of the bearing 13 of the bearing elements 2.1 or 2.2 for cushioning the pressure or air or gas can escape. This should also be within the scope of the present invention.

If the notch 8 of the damper sleeve 5 is assigned, then corresponding sealing elements are provided within the bearing 13 of the bearing elements 2.1, 2.2. If the at least one notch 8 is provided within the lateral surface 9 of the bearing 13 of the bearing elements 2.1, 2.2, corresponding sealing elements are assigned to the damping sleeve 5.

In Figures 7a and 7b side views are shown on a corresponding damper sleeve 5, from which it is seen that the notch 8 extends approximately triangular and encloses an angle β of about 30 to 90 °, preferably 60 °.

It is also within the scope of the present invention, a plurality of notches 8 in the lateral surface 9, to be distributed over the circumference, these, as in particular is shown in Figure 8a, also rectangular and as shown in Figure 8b, may also be curved.

In the embodiment of the present invention according to FIG 9 is shown enlarged in the partial cross section that the notch 8 in the region of the end face 11 has a maximum depth T, and tapers to the other opposite end face 12 in the plane of the lateral surface 9 expires. In this case, the notch 8, viewed in an axial direction, encloses an angle α of 1 ° to 3 ° and preferably 1.7 ° to 2.0 ° with respect to the jacket surface 9. However, the invention should not be limited to these angles α.

This change in the cross section or this continuous leakage of the notch 8 should also be provided in the bearing 13, as shown in particular in Figure 2. In this case, a maximum depth T should always taper from the end face 11 to the opposite end face 12 tapered.

In the exemplary embodiment according to FIG. 10, a plan view of the damper sleeve 5 is shown, in which the notch 8 is provided, for example, diagonally in the lateral surface 9. The present invention is also not limited thereto.

In a further exemplary embodiment of the present invention according to FIGS. 11 and 12, a further damper sleeve 5.1 is shown in whose lateral surface 9 at least one recess 14, in particular opening, bore or blind hole, is preferably provided axially. In essence, the recess 14 protrudes in front 11 and leads to the end face 12. The recess 14, however, is a blind hole. Furthermore, radial holes 15 from the outside meet the recess 14, as shown in the plan view according to FIG. 13.

The operation of the present embodiment corresponds approximately to that described above to the figures 2 to 6.

It is important that when entering the damper sleeve 5.1 with its end face 11 in the bearing element 2.1, 2.2 via the holes 15 between the sealing element 6 and bearing element 2.1, 2.2 compressed air for cushioning through the holes 15 expands into the recess 14 and from there over the Openings 4.1 or 4.2 of the bearing elements 2.1, 2.2 can escape.

By permanent insertion of the damper sleeve 5.1 in the bearing element 2.1, 2.2 in which a not-shown sealing element is the front side, the number of pressurized holes 14 is smaller, so that a smaller volume flow of the expanding gas through the holes 15 and recess 14th can escape for cushioning.

In this case, the individual bores 15 can be arranged axially relative to one another at variable distances A in order to influence this on a damping behavior.

Also, a diameter D of the individual holes 15 vary, so that this influence on the outflow behavior and thus the damping behavior of the compressed gas can be taken.

In particular, when engaging the end face 11 of the damper sleeve 5, 5.1 in the sealing element of the bearing element 2.1, 2.2, not shown, a so-called annular space between the sealing element 6 and the end face 11 of the bearing element 2.1, 2.2 forms.

In order to damp the end position, it has proved to be particularly advantageous to deploy the air or the gas in a determinable outflow velocity of the space formed between sealing element 6 and bearing element 2.1, 2.2.

In particular, when the sealing element 6 is close to the bearing element 2.1 or 2.2, the speed of the push rod element 3 should be damped to almost zero, without the sealing element 6 abuts against the bearing element 2.1, 2.2 at high speed. In this case, the air, as shown in particular in FIGS. 2 to 10, can be determined via the so-called notch 8, wherein it is advantageous that such a notch on the one hand does not impair the sealing element in the bearing element 2.1, 2.2 and the air, in particular the gas can flow along the notch 8, so that there is a self-cleaning.

In a further embodiment of the present invention according to Figure 14 is a partial longitudinal section through a further embodiment of a pneumatic cylinder R ₁ is shown, which corresponds approximately to the type described above. The bearing elements 2.1, 2.2, which are each provided at one end and the other end of the pneumatic cylinder R ₁ , are shown for simplicity only on one side.

To the at least one bearing element 2.1, 2.2 closes the front side of the housing 1, wherein a sealing ring 16 of an unspecified here numbered flange seals between the housing 1 and the bearing element 2.1, 2.2 produces.

Within the bearing elements 2.1, 2.2, this has a preferably cylindrically shaped cavity 17, wherein in the region of an end face 18 of the bearing elements 2.1, 2.2, the bearing 13, for example. Odometer or as a sealing ring is used.

Further, opens into the end face 18 within the housing 1, an overpressure channel 19, to which a pressure relief valve 20 connects. Essentially, the pressure relief valve 20 consists of a, the channel 19 occlusive ball-like element 21 a spring element 22 and closure element 23. These are inserted into a blind hole 24 of the bearing element 2.1, 2.2.

To the blind hole 24 further includes a bypass 25, which connects a connection between the overpressure channel 19 and the cavity 17 of the bearing elements 2.1, 2.2, when an overpressure builds up within a compression chamber 26, for the above-described escape of air through the notch 8 in the cavity 17 is insufficient.

Then, the pressure relief valve 20 is actuated, the ball 21 releases a connection between the overpressure channel 19 and bypass 25, so that the compressed air can enter the cavity 17 and from there either discharged into the environment or through the openings 4.1, 4.2 for feeding or . can escape for the discharge of air.

In the present invention has proven to be particularly advantageous that in the conventional operation, by moving the push rod element 3 with damper sleeve 5 and at least one sealing element 1 within the housing 1 in the end position compressed air in the compression chamber 26 via the notch 8 in the cavity 17th , which is connected in this position with the environment, can flow out to dampen an end position of the push rod element 3.

It should also be thought to take advantage of the overpressure, in particular the pressure relief valve 20 by means of the closure element 23 and / or the spring element 22 to ensure opening only at a determinable and selectable pressure in the compression chamber 26 and a bypass 25 to the cavity 17 release.

Preferably, the bypass 25 opens behind the storage 13 and near the opening 4.1, 4.2 in the cavity 17 a.

Important in the present invention is further that at very high masses, especially mass differences, which are moved with the pneumatic cylinder R ₁ at different speeds back and forth in the end position vibrations are reduced. Due to the additional provision of the pressure relief valve 20, which is achieved only at a certain overpressure, ie in particular shortly before a corresponding vibration by an overpressure in the end position by moving the push rod element 3 against the bearing element 2.1 or 2.2, is balanced, in which the Relief valve only briefly opens to reduce the pressure peak by discharge through the bypass 25 into the cavity 17. Only these pressure peaks are responsible for a Endlagenschwingung the push rod element 3 and are thereby prevented. Upon further movement of the push rod element 3 is permanently in the manner described above the notch 8, the air from the ever smaller compression space 26 via the notch 8 in the damper sleeve 5 in the cavity 17 expands.

This ensures that an adjustment, especially for large mass differences that can be driven with one and the same pneumatic cylinder R ₁ , is eliminated and an optimal end position damping is guaranteed.

Likewise, vibrations in the end positions are completely reduced by relieving the pressure peaks via the pressure relief valve 20.

In addition, very high speeds and in particular accelerations of large masses can be set. In particular, it is possible to move a light weight and a very heavy weight without a readjustment with one and the same pneumatic cylinder R ₁ , wherein the mass differences can be between 5 and 60 kg, preferably between 5 and 40 kg, without a readjustment being necessary.

Another advantage of the present invention is that this results in a self-adjusting end position damping in pneumatic cylinders. The novel pneumatic cylinders work in absolute Synchronization, whereby faster machine cycle times can be achieved.

It is also advantageous that no initial adjustment of the damping of the pneumatic cylinder is necessary. An end position throttling as well as throttle bores and end position throttles are eliminated. These often pollute and thus require a frequent Endlagenjustierung or readjustment of the machines. Overall, this leads to an increased service life of the pneumatic cylinders R, R ₁ . <B> Position number list </ b> 1 casing 34 67 2 bearing element 35 68 3 Push rod element 36 69 4 opening 37 70 5 damper sleeve 38 71 6 sealing element 39 72 7 pushrod 40 73 8th notch 41 74 9 lateral surface 42 75 10 phase 43 76 11 front 44 77 12 front 45 78 13 storage 46 79 14 recess 47 15 drilling 48 16 sealing ring 49 17 cavity 50 18 face 51 R pneumatic cylinder 19 Overpressure channel 52 R ₁ pneumatic cylinder 20 Pressure relief valve 53 X Double arrow 21 Bullet 54 22 spring element 55 α angle 23 closure element 56 β angle 24 blind 57 25 bypass 58 T depth 26 compression chamber 59 27 60 A distance 28 61 29 62 D diameter 30 63 31 64 32 65 33 66

Claims (11)

1. Pneumatic cylinder with end-position damping, said cylinder having a housing (1) in which is mounted, in a linearly displaceable manner, at least one push-rod member (3) with at least one sealing member (6), the push-rod member (3) having at least one damping sleeve (5) associated therewith, which, in the end positions, engages in bearing members (2.1, 2.2) on the end face, characterised in that, for end-position damping and for venting, the damping sleeve (5) or the bearing support (13) thereof has at least one notch (8), which is provided in a surface (9) substantially axially relative to the damping sleeve (5) or in the bearing support (13) thereof, the notch (8) extending from the surface (9) of the damping sleeve (5) or from the surface (9) of the mounting support (13) thereof and being introduced into said surface in an inclined manner at an angle (a) of substantially 1° to 3°, more especially 1.7° to 2.0°, and the at least one notch (8) having a triangular cross-section and being provided at an angle (b) of substantially 30° to 90°, more especially 60°.
2. Pneumatic cylinder according to claim 1, characterised in that the at least one notch (8) is provided in the surface (9) substantially axially relative to the damping sleeve (5) or substantially axially relative to the bearing support (13) thereof.
3. Pneumatic cylinder according to claim 1 or 2, characterised in that the at least one notch (8) is provided substantially parallel to the push-rod member (3) in the damping sleeve (5) or the bearing support (13) thereof.
4. Pneumatic cylinder according to at least one of claims 1 to 3, characterised in that the damping sleeve (5) is provided at one end with a chamfer (10) for engaging in at least one sealing member (6) of the bearing support (13).
5. Pneumatic cylinder according to at least one of claims 1 to 4, characterised in that the at least one notch (8) is provided at different depths (T) in the damping sleeve (5) or in the bearing support (13) thereof.
6. Pneumatic cylinder according to claim 5, characterised in that the maximum depth (T) is situated in the region of the chamfer (10) of the damping sleeve (5) or the bearing support (13) thereof, and the notch (8) extends at the other end on the end face of the damping sleeve (5) or the bearing support (13) thereof into the surface (9) in a flat manner.
7. Pneumatic cylinder according to at least one of claims 1 to 6, characterised in that the at least one notch (8) is provided in the damping sleeve (5) or the bearing support (13) thereof linearly and parallel to a longitudinal direction of said damping sleeve or bearing support, and/or extends diagonally over the surface (9) from a first end to a second end.
8. Damping sleeve, or bearing support thereof, for push-rod members (3) for pneumatic cylinders, characterised in that, for end-position damping and for venting, said damping sleeve or bearing support has at least one notch (8), which is provided in a surface (9), the notch (8) extending from the surface (9) of the damping sleeve (5) or from the surface (9) of the mounting support (13) thereof and being introduced into said surface in an inclined manner at an angle (a) of substantially 1° to 3°, more especially 1.7° to 2.0°, and the at least one notch (8) having a triangular cross-section and being provided at an angle (b) of substantially 30° to 90°, more especially 60°.
9. Damping sleeve or bearing support thereof according to claim 8, characterised in that the at least one notch (8) is provided in the surface (9) so as to extend in a longitudinal direction in an axis-parallel manner or diagonally.
10. Damping sleeve or bearing support thereof according to claim 9, characterised in that the at least one notch (8) is introduced into the surface (9) to a deeper level at one end than at the other end.
11. Damping sleeve or bearing support thereof according to at least one of claims 8 to 10, characterised in that the at least one notch (8) is deeper at one end in the region of one end face (11) and, at the other end, passes into the surface (9) so as to extend in the region of an oppositely situated end face (12).

Images