EP1621289A2 - Clamping cylinder with compact construction - Google Patents

Abstract

The clamping cylinder (10) comprises a first piston (12) axially movable inside a housing (11) and designed as a hollow element. The housing (11), serving as the linear guide for the piston (12), is fitted with two connecting points (13, 14) for oil ducts (15, 16). Two piston chambers (18, 19) are formed inside the hollow space by a second piston (20) stationary joined to the housing (11) and serving as a stop element for the first piston (12) when it is moved into an extended position.

Description

The invention relates to a clamping cylinder in a compact design with a linearly displaceable first piston having a first piston space defining first piston surface and is connected to a clamping portion, and with a linear guide for the clamping portion.

Such clamping cylinders are used when transverse forces must be absorbed in a clamping state. The disadvantage here is that especially for a large guide length, which is required for a large stroke, results in a relatively large length by the guide housing commonly used as a linear guide, a standard block cylinder upstream. Such clamping cylinders are thus large and unnecessarily expensive material.

The problem underlying the invention is to provide a clamping cylinder, which allows the inclusion of lateral forces in extended clamping section in a compact design.

The problem is solved in that in a clamping cylinder of the type mentioned, the first piston is a hollow piston, in which the first piston chamber is arranged, and that a fixed second piston is arranged in the hollow piston and limits the first piston chamber.

In this way, with the same guide length, a shorter and more compact design of the clamping cylinder according to the invention compared with a clamping cylinder with an upstream linear guide can be achieved. At the same time, it is possible to avoid a dead volume in the transition from a piston rod to the clamping section, so that contamination is prevented by the suction of, for example, cooling fluid during the alternating tensioning and relaxing and thus compressing and evacuating.

In a development of the invention, the linear guide has a guide bush which guides the hollow piston on its outer circumference. This guide bushing can be designed as a housing and is particularly well suited to receive transverse forces in different directions transverse to the clamping direction.

Preferably, the hollow piston also has a second piston space, which is bounded by the second piston and a second piston surface facing the first piston surface. In this way, a retraction or retraction of the hollow piston is possible by pressurizing the first piston chamber or the second piston chamber. It has proved to be of particular advantage when a third piston chamber is provided, which is delimited by a third piston surface facing away from the clamping portion and a housing. In this way, a higher clamping force can be achieved with the same cross-section of the clamping portion and thus comparable stable design against lateral forces, since the first piston surface and the third piston surface can be acted upon together for clamping with pressure.

An embodiment of the invention is characterized in that oil passages are provided in the second piston and / or the associated piston rod for acting on the first, second and / or third piston chamber with oil. As a result, a serving as a linear guide housing can be particularly simple. In addition, there is a reliable and easy supply of the piston chambers with oil. A particularly simple structure also results if the first, second and / or third piston surface is integral with the hollow piston. But it is also possible that the first, second and / or third piston surface can be inserted into the hollow piston.

If the first piston chamber and the third piston chamber can be acted upon together with pressure for clamping, and if the sum of the first piston surface and the second piston surface is greater than the cross-sectional area of the hollow piston, results in a particularly large clamping force with compact dimensions.

Preferably, sealing means are provided between the hollow piston and the guide bush at the end facing away from the clamping section. This results in the one hand, good protection against contamination, since the sealant are far away from the open end of the clamping cylinder. At the same time, however, a lubrication of the piston with drag oil is possible. A variable piston travel query can be made possible thereby.

In a separately usable embodiment of the invention, a parallel to the linear guide direction arranged crank pin is provided as a rotation, which cooperates with a slide track on the outer peripheral surface of the hollow piston. This type of anti-rotation is particularly durable and at the same time robust. The slide pin may be formed at its end facing the clamping portion of the outer circumference of the hollow piston and engage under a arranged between the hollow piston and the linear guide bushing stripping. Because a simple scraper ring can be used as scraper, thereby a contamination of the space between the hollow piston and linear guide is particularly effectively prevented. Preferably, the link pin is used with sealants in the slide track. As a result, the escape of, for example, oil in the gate guide is effectively prevented, without resulting in a complex and thus prone structure for a possible sealing ring.

An advantageous development of the invention, but in principle can also be used independently of the invention, results from the fact that a receptacle for a function carrier is provided on the side facing away from the piston surface side of the clamping portion. This allows a variety of purposes. Preferably, locking means are also provided for locking the function carrier in the receptacle. The receptacle may be, for example, a bore. As locking means are radially insertable threaded pins with apex and / or a coupling ring with internal thread. In the embodiment with the coupling ring, a flange-like bead should be provided surrounding the receptacle.

If the function carrier has the first piston surface and is sealed by means of a sealing element in the hollow piston, there is a special easy mounting option. In this case, it is possible that the piston chamber is part of a through hole, which is closed on one side, that the function carrier is screwed. Hollow piston and function carrier may be integrally formed. It is also advantageous if a common housing is provided for hollow piston and function carrier. This gives a good protection and a robust design. If a further rotation for the function carrier is provided, also an undesirable rotation of the function carrier can be avoided against the hollow piston.

In a further development, movable functional elements are provided. The functional elements may have two substantially mutually perpendicular clamping surfaces. This makes it possible that the functional elements deflect a part of the clamping force at right angles to the clamping direction during clamping. This is the case in particular when the functional elements are designed to be rotatable or slidable obliquely relative to the two clamping surfaces.

An advantageous development also results by providing a return element for resetting the functional elements in a starting position. In this way, the clamping cylinder is ready for use again after resetting the functional element. A provision of the functional elements can be done for example by spring force. However, in the case of stiffness, for example due to contamination in the automatic workflow, this embodiment is prone to failure. The restoring element may be, for example, a return bolt, which is displaceable parallel to its longitudinal direction, is supported in the initial position on the second piston and secures the functional element against removal. In this case, the functional element has a recess into which the restoring element engages for cooperation. The functional element can be removed only after pushing the return element out of the recess. On the other hand, this linear adjustable return bolt provides a simple drive option by supporting on the second piston. Preferably, the restoring element is subjected to pressure during clamping. As a result, a defined initial position of the functional element is assumed during the entire tensioning process.

Fig. 1

Eine schematische Darstellung eines ersten Ausführungsbeispiels eines Spannzylinders mit den Erfindungsmerkmalen in einem entspannten Zustand,

Fig. 2

den Schnitt C-C von Figur 1,

Fig. 3

den Spannzylinder von Figur 1 in gespanntem Zustand,

Fig. 4

ein zweites Ausführungsbeispiel eines Spannzylinders mit den Erfindungsmerkmalen,

Fig. 5

eine Schnittdarstellung des zweiten Ausführungsbeispiels ähnlich Figur 2,

Fig. 6

ein drittes Ausführungsbeispiel eines Spannzylinders mit den Erfindungsmerkmalen,

Fig. 7

eine schematische Darstellung eines vierten Ausführungsbeispiels eines Spannzylinders mit den Erfindungsmerkmalen mit einem beweglichen Funktionselement,

Fig. 8

eine Vorderansicht auf den vierten Spannzylinder mit dem beweglichen Element,

Fig. 9

eine schematische Darstellung zur Montage des beweglichen Funktionselementes in dem Funktionsträger von Figur 7,

Fig. 10

ein weiteres Ausführungsbeispiel eines Spannzylinders mit den Erfindungsmerkmalen mit einem beweglichen Funktionselement, und

Fig. 11

eine Vorderansicht auf das weitere Ausführungsbeispiel des Spannzylinders von Figur 10.

Embodiments will be explained in more detail with reference to the drawings. Show it:

Fig. 1

A schematic representation of a first embodiment of a clamping cylinder with the invention features in a relaxed state,

Fig. 2

the section CC of Figure 1,

Fig. 3

the clamping cylinder of Figure 1 in a stretched state,

Fig. 4

A second embodiment of a clamping cylinder with the features of the invention,

Fig. 5

a sectional view of the second embodiment similar to Figure 2,

Fig. 6

A third embodiment of a clamping cylinder with the features of the invention,

Fig. 7

1 is a schematic representation of a fourth embodiment of a clamping cylinder with the features of the invention with a movable functional element,

Fig. 8

a front view of the fourth clamping cylinder with the movable element,

Fig. 9

a schematic representation of the assembly of the movable functional element in the function carrier of Figure 7,

Fig. 10

a further embodiment of a clamping cylinder with the features of the invention with a movable functional element, and

Fig. 11

a front view of the further embodiment of the clamping cylinder of Figure 10.

Figure 1 shows a schematic representation of a clamping cylinder 10 with the features of the invention in a sectional view. The clamping cylinder 10 has a housing 11 and a first piston 12. The first piston 12 is arranged linearly displaceable in the housing 11 and designed as a hollow piston 12. The housing 11 has two ports 13, 14 for oil pressure lines, which communicate with oil passages 15, 16, respectively.

The hollow piston 12 has a bore 17 which forms a first piston chamber 18 and a second piston chamber 19, which are separated from each other by means of a piston 20. The piston 20 is a fixed piston 20 which is fixedly fixed with respect to the housing 11 and except for the formation of three separate Piston chambers 18, 19, 25 serves as an end stop of the extended hollow piston 12.

The bore 17 is closed in the embodiment shown by means of a functional support 21 which has a first piston surface 22 on its side facing the piston 20. Adjacent to the first piston surface 22 is a sealing ring 23 surrounding the function carrier 21 and sealingly arranged against the hollow piston 12.

At the end remote from the function carrier 21 end of the hollow piston 12, the piston 20 facing a second piston surface 24 is arranged. The first piston surface 22 and the piston 20 define the first piston chamber 18, and the second piston surface 24 and the piston 20 together define the second piston chamber 19.

A third piston chamber 25 is arranged between the end remote from the functional member 21 of the hollow piston 12 and the housing 11, wherein the third piston chamber 25 of the housing 11 and facing away from the functional member 21 end of the hollow piston 12 facing the housing 11 arranged stepped third piston surface 26 is limited. The hollow piston 12 is sealed against the housing 11 on its outer peripheral surface at the end facing away from the function carrier 21 by means of a sealing ring 27, which is arranged in a groove 28. Similarly, the hollow piston 12 is sealed by means of a sealing ring 29 which is arranged in a groove 31 against a piston rod 30 which carries the piston 20 and fixed in relation to the housing 11 fixed. The piston rod 30 is fixed by means of a nut 32 on the housing 11. In the piston rod 30 oil passages 33, 34 are arranged. In this case, the oil passage 33 is connected to the oil passage 15 via the third piston chamber 25. In addition, the oil passage 33 connects the first piston chamber 18 with the third piston chamber 25. The oil passage 34 in turn connects the oil passage 16 with the second piston chamber 19. The two outer piston chambers 25 and 18 cause under oil pressure the extension of the hollow piston 12, while the inner piston chamber 19th the retraction of the hollow piston 12 causes.

In addition to the linear guide of the hollow piston 12, which is formed by its outer circumference and the bore in the housing 11, the clamping cylinder 10 also has an anti-rotation device for the hollow piston 12. The rotation is essentially formed by a slide track 35 and a connecting bolt 36. The slide track 35 is on the functional carrier 21 facing the end of the hollow piston 12 extending in the longitudinal direction and arranged on the outer peripheral surface. How, for example, Figure 2 can be seen, the slide track 35 has a part-circular cross-section in the embodiment shown. The link pin 36 is, as can be seen also Figure 2, provided with a circular cross-section corresponding to the slide track 35. In this case, the functional carrier 21 facing the end of the slide pin 36 of the outer peripheral surface of the hollow piston 12 is formed accordingly. For this purpose, the guide bolt 36 has at its end facing the function carrier 21 a surface 37 whose contour corresponds to the outer peripheral surface of the hollow piston 12. At its end facing the function carrier 21, the housing 11 has an annular groove 38, in which a scraper ring 39 is arranged. As can be seen from FIGS. 1 and 2, the guide bolt 36 engages under its end facing the function carrier 21, namely the surface 37, the scraper ring 39. The slide bolt 36 also has a groove 40 in which a sealing ring 41 is arranged. As can also be seen from FIG. 1, the function carrier 21 is fastened to the hollow piston 12 by means of a union nut 42. In addition, the piston 20 has a sealing ring 43 for sealing the first piston chamber 18 against the second piston chamber 19.

The function of the clamping cylinder 10 will be explained below with reference to FIGS. 1-3. In the state shown in Figure 1, the hollow piston 12 is retracted to its relaxed position. For this purpose, by applying the port 14 with pressurized oil, as indicated by the arrow B, this oil is passed through the oil passages 16 and 34 into the second piston chamber 19. There, the oil acts on the second piston surface 24, wherein the fixed piston 20 serves as an abutment, and thus pushes the hollow piston 12 in the illustrated relaxed position.

To extend the piston in the tensioned position shown in Figure 3, the port 13 is pressurized with oil, as indicated by an arrow A. From the port 13, the pressure oil is passed through the oil passage 15 in the third piston chamber 25 and from there via the oil passage 33 into the first piston chamber 18. By acting on the first piston surface 22 and the third piston surface 26 oil pressure of the hollow piston 12 is then extended into the tensioned position shown in Figure 3, wherein the piston 20 and the housing 11 each serve as an abutment. The interaction of the first piston surface 22 and the third piston surface 26 results in a larger pressure surface and thus a greater clamping force than would be possible by the pressurization of a piston with the cross-sectional area of the hollow piston 12. In the embodiment shown, the interaction of the first piston surface 22 with the third piston surface 26 results in an approximately 20% higher clamping force than with a piston of the cross-sectional area of the hollow piston 12 Extending the hollow piston 12 in the tensioned position shown in Figure 3 hydraulic oil passes from the third piston chamber 25 to the sealing ring 27 and wets the wall surface of the bore in the interior of the housing 11. In this way, the hydraulic oil is used as a so-called drag oil for lubrication At the same time, the sealing ring 41 prevents leakage of the trailing oil through the groove 35.

When returning the hollow piston 12 to the relaxed position shown in FIG. 1, the scraper ring 39 prevents contaminants reaching the outer peripheral surface of the hollow piston 12 from being drawn into the region between the hollow piston 12 and the housing 11. In particular, in the region of the sliding bolt 36 is achieved by means of which the scraper ring 39 with the surface 37 a secure stripping, with a high reliability and low cost of the components used are achieved. The formation of the link bolt 36 with its seals only allows the escape of the slide track 35 of the hollow piston 12 from the housing bore of the housing 11 and thus shortens the slide track 35 and the housing 11 considerably.

Figure 4 shows a clamping cylinder 44 as a second embodiment with the features of the invention in a sectional view. The clamping cylinder 44 corresponds structurally substantially to the clamping cylinder 10. The same elements bear the same reference numerals, with individual elements, such as the anti-rotation, and individual reference numerals have been omitted for clarity. In contrast to the clamping cylinder 10, the clamping cylinder 44 has a housing 45 and a hollow piston 46, which is similar to the hollow piston 12 constructed. In contrast to the hollow piston 12, the hollow piston 46 has no union nut 42 but threaded pins 48 for attachment of a function carrier 47. In the housing 45 also sensors 49, 50 are arranged in bores 51, 52. The sensor 50 is screwed by means of a thread in the bore 52 and detects the remote from the function carrier 47 end of the hollow piston 46. The bore of the sensor 50 protrudes into the third piston chamber 25 and must therefore be sealed oil pressure tight.

The sensor 49 is connected by means of a thread with a mounting plate 52, which in turn is connected by means of screws 54 to the housing 45. The screws 54 are arranged in oblong holes 53 in the mounting plate 52. The elongated holes 53 and the bore 51 allow a displacement of the mounting plate 52 with the sensor 49 parallel to the longitudinal axis of the hollow cylinder 46, as indicated by a double arrow C. The sensor 49 detects the presence of a recess 51 in the outer peripheral surface of the hollow piston 46. Since the sensor 49 does not protrude into a piston chamber with its oblong hole bore 51 (during the entire piston stroke), the displacement of the sensor 49 for adjustment without pressure sealing becomes possible in the first place.

As can be seen from FIG. 5, four setscrews 48 with a conical tip are provided for fastening the function carrier 47.

The sensors 49, 50 can serve as limit switches, for example. In particular, by means of the sensor 49, an adjustment of the stroke of the hollow piston 46 is possible.

Figure 6 shows a schematic representation of a clamping cylinder 55 as a third embodiment with the features of the invention. The clamping cylinder 55 corresponds in terms of its construction essentially the clamping cylinder 10 and the clamping cylinder 44. The same elements bear the same reference numerals. For a better overview, the housing 11 is partially omitted. In contrast to the clamping cylinders 10 and 44, the clamping cylinder 55 has a hollow piston 56 which is closed at the front side. Specifically, the hollow piston 56 is closed at its right in the figure, so that a first piston surface 59 for limiting the first piston chamber 18 part of the hollow piston 56 and not as in the clamping cylinder 10 and the clamping cylinder 44 is part of the function carrier 21, 47. In the hollow piston 56 is therefore a second piston surface 60 for limiting the second piston chamber 19 and a third piston surface 61 for limiting the third piston chamber 25 part of a closure piece 62 which is screwed by means of a thread 63 with the hollow piston 56. For sealing the second piston chamber 19 from the third piston chamber 25, the end piece 62 has a sealing ring 65 arranged in a groove 64 and a sealing ring 67 arranged in a groove 66.

The hollow piston 56 has at its closed end a receptacle 57 for a function carrier not shown in the figure. For example, this function carrier can be screwed to the receptacle 57 with an internal thread 58. But it is also a use of grub screws 48 possible.

Figure 7 shows a clamping cylinder 68 as a third embodiment with the features of the invention in a sectional view. The clamping cylinder 68 corresponds in its operation to the clamping cylinders 10, 44 and 55. The same elements bear the same reference numerals. For clarity, a number of items are not provided with reference numerals or shown in the figure. The clamping cylinder 68 differs from the clamping cylinders 10, 44 and 55 by the use of a modified function carrier 69. The function carrier 69 has a receiving piece 70 for a functional element 71. In addition, the function carrier 69 has a through hole 72 which extends through the first piston surface 22 therethrough. Inside the bore 72, a return bolt 73 is arranged. The return pin 73 has an elongated, substantially cylindrical shape. On its outer peripheral surface, the return pin 73 has a circumferential groove 74, in which a sealing ring 75 is arranged. At its end facing away from the piston surface 22, the return bolt 73 has a spherical tip, with which the return bolt 73 cooperates with a recess 77 in the functional element 71. The functional element 71 is formed substantially circular disk-shaped, wherein on its side facing away from the recess 77 side a further recess is provided which forms two mutually inclined surfaces 78, 79. The inclined surfaces 78, 79 are arranged at an acute angle to each other. In the embodiment shown, the surfaces 78, 79 form an angle of about 45 with each other. As can be seen from FIG. 7, the return bolt 73 abuts the piston 20 in a state shown by solid lines, whereby the functional disk 71 is forcibly swung back into an initial position such that the recess 77 bears against the tip 76 of the return bolt 73. When extending the hollow piston 12 in a clamping state, the first piston chamber 18 is acted upon by hydraulic oils, which in addition to the first piston surface 22 and the end remote from the tip 76 of the restoring pin 73 is under oil pressure and so holds the functional disk 71 in the position shown. Upon reaching the clamping position shown with broken lines, first the surface 78 abuts with its rounded front edge to a workpiece 80 which is arranged by means of supports 82 on a workbench 81. By abutting the surface 78 against the workpiece 80, the function disc 71 is rotated against the restoring force of the acted upon by the oil pressure return bolt 73 in the clockwise direction until reaching the position shown in dashed lines, in which both surfaces 78 and 79 abut the workpiece 80. As a result of the clamping force of the clamping cylinder 68 directed to the right in FIG. 7, a force is simultaneously exerted on the workpiece 80 in the figure and downwards, which together lead to the force vector designated by the arrow F on the workpiece 80.

The insertion of the functional disk 71 into the receiving piece 70 will be described below with reference to FIGS. 8 and 9. As can be seen from the figures, the receiving piece 70 has a receptacle 83, the contour of which is adapted to the outer circumference of the functional disk 71. The receptacle 83 laterally delimiting a boundary 84 is provided, so that the functional disk 71 in the inserted state can not laterally slip out of the receptacle 83. To insert the function disc 71 in the receptacle 83 is the Function disc 71 pivoted so that the surfaces 78, 79 are turned in the figure obliquely to the bottom left. In this way, the functional disk 71 can be inserted into the receptacle 83, as shown schematically in FIG. After inserting the functional disk 71 into the receptacle 83, the functional disk 71 is then pivoted into the starting position shown in FIG. 7 by solid lines. If the return bolt 73 is then inserted from the left into the bore 72 in the figure until the tip 76 bears against the recess 77, an accidental sliding away of the housing and thus losing the functional disk 71 from the receptacle 83 is prevented. As a result of this design of the functional disk 71 with its receptacle 83, which accounts for more than half of the circumference, the surfaces 78 and 79 can be extended into the center region of the functional disk 71.

Figure 10 shows a clamping cylinder 85 as a further embodiment of the invention. The clamping cylinder 85 substantially corresponds to the clamping cylinder 68. The same elements bear the same reference numerals. As with the clamping cylinder 68, the terms for individual elements as well as individual elements are omitted for clarity. As the figure 10 can be seen, the clamping cylinder 85 has a function carrier 86 with a receiving piece 87. The receiving piece 87 has an obliquely displaceable functional element 88 that with a arranged in a bore 89 in the function carrier 86 return pin 90 similar to the return pin 73 in Connection stands. The return pin 90 has a groove 91 in which a sealing ring 92 is arranged.

The functional element 88 is a cocking slide 88, which is arranged in a receptacle in the receiving piece 87 and along a, the receiving limiting bevel 93 is displaceable, as indicated by a double arrow. The cocking slide 88 has two mutually perpendicular clamping surface 94, 95. On the side facing away from the surfaces 94, 95 side of the cocking slide 88, a recess 96 is arranged, with the return bolt 90 is in communication in the assembled state.

FIG. 11 shows a front view of the clamping cylinder 85.

As can be seen from FIG. 10, the return bolt 90 abuts the piston 20 in an initial position and thus presses the cocking slide 88 obliquely upward along the bevels 93 until the end of the return bolt 20 facing away from the piston 20 abuts against a lower stop Recording 96 abuts. When pressurizing the first piston chamber 18 with pressure oil, the hollow piston 12 is moved in the figure to the right until the drawn with dashed lines clamping position is reached. It will First, the cocking slide 98 held by the pressurized oil return bolt 90 in the starting position. When the surface 95 hits the workpiece 80 held on the support 97, the clamping slide 88 can move along the bevels 93 to such an extent that the surface 94 also bears against the workpiece 80. When clamping the clamping cylinder 85 by pressurizing the piston chamber 18, a force is then exerted both in the figure to the right and down on the workpiece 80 by the cocking slide 88, as indicated by the arrow F as a resultant force.

For mounting the cocking slide 88 is inserted with pushed back retainer 90 along the slope 93 in the receptacle of the receiving piece 87 and then secured by advancing the return pin 90 against accidental Herhausgleiten.

List of reference numbers:

10

clamping cylinder

11

casing

12

hollow piston

13

connection

14

connection

15

oil passage

16

oil passage

17

drilling

18

first piston chamber

19

second piston chamber

20

piston

21

officials

22

first piston surface

23

seal

24

second piston surface

25

third piston chamber

26

third piston area

27

seal

28

groove

29

seal

30

piston rod

31

groove

32

mother

33

oil passage

34

oil passage

35

link path

36

setting bolt

37

area

38

groove

39

scraper

40

groove

41

seal

42

Nut

43

seal

44

clamping cylinder

45

casing

46

hollow piston

47

officials

48

Set screw

49

sensor

50

sensor

51

recess

52

mounting plate

53

Long hole

54

screw

55

clamping cylinder

56

hollow piston

57

admission

58

inner thread

59

first piston surface

60

second piston surface

61

third piston area

62

terminating piece

63

thread

64

groove

65

seal

66

groove

67

seal

68

clamping cylinder

69

officials

70

spigot

71

functional element

72

drilling

73

Reset pin

74

groove

75

seal

76

top

77

recess

78

area

79

area

80

workpiece

81

worktable

82

edition

83

admission

84

limit

85

clamping cylinder

86

officials

87

spigot

88

functional element

89

drilling

90

Reset pin

91

groove

92

poetry

93

slope

94

area

95

area

96

recess

97

edition

98

locking pin

99

officials

100

locking pin

Claims (18)

Clamping cylinder in a compact design with a linearly displaceable first piston (12, 46, 56) having a first piston chamber (18) defining the first piston surface (22, 59) and is connected to a clamping portion (21), and with a linear guide for the Clamping section (21), characterized in that the first piston is a hollow piston (12, 46, 56), in which the first piston chamber (18) is arranged, and in that a fixed second piston (20) in the hollow piston (12, 46, 56) is arranged and the first piston space (18) limited. Clamping cylinder according to claim 1, characterized in that the linear guide has a guide bush (11, 45) which guides the hollow piston (12, 46, 56) on its outer periphery. Clamping cylinder according to claim 1 or 2, characterized in that the hollow piston (12, 46, 56) has a second piston chamber (19), by the second piston (20) and one of the first piston surface (22, 59) facing the second piston surface ( 24, 60) is limited. Clamping cylinder according to one of the preceding claims, characterized by a third piston chamber (25) which is delimited by a third piston surface (26, 61) facing away from the clamping portion (21) and a housing (11, 45). Clamping cylinder according to one of the preceding claims, characterized by oil passages (33, 34) in the second piston (20) and / or the associated piston rod (30) for acting on the first (18), second (19) and / or third piston chamber ( 25) with oil. Clamping cylinder according to one of the preceding claims, characterized in that the first (22, 59), second (24, 60) and / or third piston surface (26, 61) with the hollow piston (12, 46, 56) is in one piece. Clamping cylinder according to one of claims 1 to 5, characterized in that the first (22, 59), second (24, 60) and / or third piston surface (26, 61) in the hollow piston (12, 46, 56) can be inserted. Clamping cylinder according to one of the preceding claims, characterized in that the first piston chamber (18) and the third piston chamber (25) for clamping together with pressure can be acted upon, and that the sum of the first piston surface (22, 59) and the third piston surface (26, 61) is greater than the cross-sectional area of the hollow piston (12, 46, 56). Clamping cylinder according to one of the preceding claims, characterized by sealing means (27) between the hollow piston (12, 46, 56) and the guide bush (11, 45) at the end remote from the clamping portion (21). Clamping cylinder according to one of the preceding claims, characterized in that a parallel to the linear guide direction arranged guide pin (36) is provided as anti-rotation, which cooperates with a slide track (35) on the outer peripheral surface of the hollow piston (12, 46, 56) and in particular with sealing means ( 41) is inserted into the slide track (35). Clamping cylinder according to claim 10, characterized in that the slide pin (36) at its the clamping portion (21) facing the end of the outer periphery of the hollow piston (12, 46, 56) is formed accordingly and between the hollow piston (12, 46, 56) and the linear guide bushing (11, 45) engages under stripping means (39). Clamping cylinder according to one of the preceding claims, characterized by a receptacle (57), which in particular locking means (42, 48, 58, 98) for locking the function carrier (21, 47, 69, 86) in the receptacle (57), for a Function carrier (21, 47, 69, 86, 99), which preferably has the first piston surface (22, 59) and by means of a sealing element (23) in the hollow piston (12, 46) is sealed, at the of the first piston surface (22 , 59) facing away from the clamping section. Clamping cylinder according to claim 12, characterized in that the locking means radially insertable profit pins (48) with apex, a coupling ring (42) with internal thread and / or a locking pin (98, 100). Clamping cylinder according to claim 12 or 13, characterized by a common housing (11, 45) for the hollow piston (12, 46, 56) and the function carrier (21, 47, 69, 86, 99). A clamping cylinder according to any one of claims 12 to 14, characterized by a further anti-rotation device (98, 100) for the function support (21, 47, 69, 86). Clamping cylinder according to one of claims 12 to 15, characterized by movable functional elements (71, 88) which in particular have two substantially mutually perpendicular clamping surfaces (78, 79, 94, 95). Clamping cylinder according to claim 16, characterized in that the functional elements (71, 88) deflect a part of the clamping force at right angles to the clamping direction during clamping. Clamping cylinder according to claim 16 or 17, characterized by a return element (73, 90) for returning the functional elements (71, 88) to a starting position, which in particular is a return bolt (73, 90) which is displaceable parallel to its longitudinal direction, in the Starting position on the second piston (20) is supported, and the functional element (71, 88) secures against removal and is preferably applied during clamping with pressure.

Images