KR20170082500A

KR20170082500A - Piston and positioning device equipped therewith

Info

Publication number: KR20170082500A
Application number: KR1020177007446A
Authority: KR
Inventors: 외르크 베젤러; 클라우스 라이헤르트; 다니엘라 클레스만
Original assignee: 페스토 악티엔 게젤샤프트 운트 코. 카게
Priority date: 2014-11-12
Filing date: 2014-11-12
Publication date: 2017-07-14
Also published as: CN107076179A; CN107076179B; WO2016074691A1; EP3164610A1; EP3164610B1

Abstract

The present invention relates to a piston (4) for a positioning device which can be actuated by a fluid, the piston having an integral piston body (16) in which a longitudinal axis (5) of the piston (4) An annular receiving groove 25 coaxial with the receiving grooves 25 is formed, and this receiving groove has two side groove flank 33a and 33b facing each other. In the receiving groove 25, there is a permanent magnet assembly 24 consisting of a permanent magnet magnet band 35 which is bent in a ring-like structure and which has two band end sections 35a , 35b. The magnet bands 35 have a smaller width than the receiving grooves 25 and in this case each of the two band end sections 35a and 35b are tightly clamped in the receiving groove 25. Clamping is responsible for one or more clamping protrusions 46a, 47a, 46b, 47b protruding from one groove flank of the groove flank 33a, 33b.

Description

PISTON AND POSITIONING DEVICE EQUIPPED THEREWITH BACKGROUND OF THE INVENTION Field of the Invention [0001]

The present invention relates to a piston for a positioning device which can be actuated by a fluid, in particular a piston for a fluid actuated linear drive, the piston having an integral piston body, the piston body having its own radial outer periphery An annular receiving groove coaxial with the longitudinal axis of the piston, with two lateral groove flanks facing each other, in which a permanent magnet assembly, which can be used for position detection, is housed . The present invention also relates to a positioning device which can be actuated by a fluid, said positioning device being in particular a fluid actuated linear drive device and having a housing in which a piston is arranged for linear movement .

A piston-mounted positioning device of the type described above is known from DE 20 2005 005 508 U1 and is formed, for example, as a linear drive or as a shock absorber. During operation of the positioning device, the piston is moved relative to the housing of the positioning device, in this case in order to enable the position detection of the piston by interaction with the external position detection means, a permanent magnet assembly Can be used. In order to be able to manufacture the piston cost-effectively, the piston comprises an integral piston body with peripheral receiving grooves, in which a permanent magnet assembly is inserted. The permanent magnet assembly consists of a plurality of arc-shaped magnet segments which are inserted into the receiving groove from the outside in the radial direction when mounting the piston. However, the manufacture and assembly of the magnet segments is relatively complex.

In the piston described in DE 20 2005 005 508 U1 described above, a guide band having an annular structure is additionally mounted, and this guide band is inserted into the annular fixed recess formed on the outer periphery of the piston body . The guide band is formed as a hollow cylindrical guide ring in which one end of its circumference is interrupted, so that the guide ring can be temporarily enlarged at the time of assembly due to its elasticity. The radially outer surface of the guide band defines a guide surface that slidably contacts the inner circumferential surface of the housing housing the piston so that the piston is able to perform linear motion relative to the housing, have.

DE 19715858 A1 discloses a piston for an operating cylinder in which an annular permanent magnet is mounted for position detection. In order to enable assembly of the annular magnet, it has been proposed to constitute the piston body in several parts. The piston body consists of two piston elements which are mutually coupled together forming a receiving groove which are coated with an elastomeric material in the region of the receiving groove so as to hold the permanent magnet and secure it in a secure manner .

EP 0 307 569 A2 describes a piston-cylinder device in which the piston has an integral piston body on which a guide band with its one perimeter is interrupted is seated in the periphery . The guide band has elastic spring characteristics and is snap-in coupled to the interior of the annular groove formed in the outer periphery of the piston body, similar to a spring. In order to enable the position detection of the piston, the piston body has a recess at one point on its outer periphery, and a permanent magnet member covered with a guide band is inserted in the recess.

It is an object of the present invention to seek measures to enable a piston with a permanent magnet assembly, which can be used for position detection, to be mounted in a cost effective manner.

In order to solve the above problem, in the piston of the type mentioned in the preamble, the permanent magnet assembly is made of a resilient permanent magnet magnet bending in a ring structure, and the magnet bands face each other in the circumferential direction of the receiving groove It is proposed that the width of the magnet band is smaller than the spacing of the two groove flanks of the receiving groove, in which case each of the two band end sections is clamped by the clamping in the circumferential direction of the receiving groove Wherein the piston body is fixed within one of two clamping zones of adjacent adjacent receiving grooves and wherein the piston body projects under a localized stenosis of the receiving grooves respectively with respect to one groove flank of the groove flanks, At least one clamping projection projecting from the clamping projection.

The present invention is also solved by the fact that, in a positioning device of the type mentioned in the preamble, which can be actuated by a fluid, the piston formed in the abovementioned intention is mounted on the positioning device.

In this manner, the permanent magnet assembly, which can be used for position detection, for example, can be mounted very simply on an integral piston body that can be manufactured in a cost effective manner. As a permanent magnet assembly, a magnet band that is resiliently wheeled and has permanent magnetism is used, which is placed around the piston body and inserted into the receiving groove for assembling to the piston body. In this case, the magnet bands are positioned so that the two band end sections of the magnet bands facing each other lie in one clamping region of the piston body, wherein the receiving grooves are adjacent to each other in the circumferential direction of the receiving groove It has two clamping zones. At this time, each of the two band end sections is disposed within one clamping zone of the two clamping zones. Each clamping zone is characterized in that at least one of the two groove flanks of the receiving groove is provided with a clamping protrusion protruding above the associated groove flange. In this way, the width of the receiving groove in the area of each clamping projection is smaller than the inner spacing of the two groove flanks facing each other, which is larger than the width of the magnet flange. Thus, the magnet bands can be easily inserted into the receiving groove by being disposed around the piston body or bending around the piston body in areas that lie outside the clamping area, while the two band end sections are each located within the associated clamping area It can be pushed into the receiving groove with a slight pressure. By means of one or more clamping projections in the clamping zone, a magnet band is provided on the side and clamped tightly in the receiving groove. If the magnet bands are fixed in the receiving groove in this manner, the band end sections can no longer be unfolded, so that the piston can then be inserted very simply into the housing of the associated positioning device. In this case, it is not necessary to fix the magnet band manually or using the assembling device until the piston is inserted into the housing of the positioning device. A further advantage of the design according to the invention is that the relevant components can be produced cost-effectively by non-cutting type molding as desired. The intended shaping can also result in tolerance compensation exceeding a large tolerance range that ensures reliable fixation of the magnet band in the receiving groove. Because the assembly of the magnet bands is so simple, the required assembly steps may be automated as needed, and such automation further reduces manufacturing costs for the pistons.

Advantageous refinements of the invention are evident from the dependent claims.

Preferably, the piston body in each clamping zone of the receiving groove is equipped with a plurality of clamping protrusions, each contacting a respective band end section.

One embodiment is possible in which at least a pair of clamping projections per clamping zone are directly opposed in the axial direction of the piston. In this way, the associated band end sections are tightly fixed between the clamping protrusions directly facing each other. However, since such measures are relatively strongly associated with the tolerances in relation to the safety of the stationary clamping, the piston bodies in the respective clamping zones of the receiving grooves are arranged in spaced relation to each other in the circumferential direction of the receiving grooves The clamping protrusions of the clamping protrusions are considered to be more preferable. In other words, there are a plurality of clamping projections per clamping zone, which are arranged displaced with respect to one another at intervals in the circumferential direction of the receiving grooves.

One embodiment in which in each clamping zone there are two or more and especially exactly two clamping protrusions disposed adjacent to one another in the circumferential spacing of the receiving grooves and these clamping protrusions are assigned to different groove flanks, . More specifically, if the first clamping protrusion is disposed in one groove flank, the clamping protrusion spaced relative to it in the circumferential direction of the receiving groove is present in the opposing groove flanks. At this time, it is highly desirable that none of the clamping protrusions are opposed to the clamping protrusions assigned to the respective different groove flank. Hence, in the region of each clamping projection, the associated band end section is tightly fixed between the one clamping projection of the clamping projections on one side and the opposing groove flanks on the other. The clamping protrusions are alternately arranged in the two groove flanks, so that the band end section almost passes through the clamping zone or has a slightly wavy vertical waveform. The formation of a clamping zone in this manner is not extremely sensitive to tolerances and guarantees reliable fixed clamping of the individual band end sections even when the tolerance range is large, which leads to particularly low manufacturing costs.

It has proved desirable to have the inner spacing of the two protrusions spaced apart from each other in the circumferential direction of the receiving groove measured and projected in the longitudinal direction of the piston to be less than the width of the magnet band. Since the clamping protrusions are spaced apart from each other, the band end section can likewise be inserted relatively simply or radially outwardly into the receiving groove.

Preferably, the inner spacing of the opposing groove flanks of each clamping projection and receiving groove is equal to or greater than the width of the magnet band.

Furthermore, the spacing of the clamping protrusions arranged in different groove flank, measured in the circumferential direction of the receiving groove in the individual clamping zone, is at least equal to the width of the magnet band, but at most twice the width of the magnet band Has proven to be preferable. By such a method, a particularly reliable clamping effect is obtained.

The clamping projection may be formed arbitrarily, and may be structured, for example, in the shape of a nep. It is considered particularly preferable that the clamping protrusions are each formed into a rib shape having an introductory shape and each extend from the region of the groove bottom to the direction of the radial groove opening of the receiving groove.

It is also preferable that the clamping projection is inclined toward the associated groove flank in its end region toward the radial groove opening side. In this way, the band end section to be fixed can be pushed very comfortably into the receiving groove.

For magnet bands, a rectangular cross-section is recommended which can be manufactured cost-effectively. As a magnet band, a strand body which is preferably bent in a desired ring shape is used, and the two band end sections of such a strand are loosely tangent to each other or slightly spaced from each other.

Preferably, the magnet band consists of a strand-shaped band body made of a plastic material which is elastically deformable and provided with permanent magnet means. As the permanent magnet means, preferably ferromagnetic particles incorporated in the band body and magnetized as required are used.

The integral piston body is preferably made of a rigid material. This applies correspondingly to the clamping projection, which is an integral component of the piston body. For example, the piston body is made of metal, ceramic, glass or hard plastic material.

The case where the piston body has only two clamping zones provided with two adjacent clamping zones as well as the above two clamping zones assigned to the peripheral zone set in the direction opposite to each other of the piston body desirable. In this way, there is greater variability when inserting the magnet band into the receiving groove.

In addition to the magnet band, it is advantageous if the piston has a guide band suitable for a linear guide of the piston in the housing of the positioning device. The guide bands are arranged coaxially with respect to the piston body in the same manner as the magnet bands.

The guide band is seated in an annular fixed recess formed in the piston body in a preferred manner which concentrically surrounds the annular receiving groove and has a greater axial width than the receiving groove. In this way, the receiving groove with the groove opening lying outside in the radial direction communicates with the interior of the recessed bottom of the fixed recess. An annularly structured guide band mounted within the fixed recess surrounds the magnet band radially outside and covers the magnet band in a preferred manner.

When the guide band is inserted into an annular fixed recess coaxial with respect to the longitudinal axis of the piston and fixed in the radial direction inside the fixed recess in a shape-fitting manner with respect to the longitudinal axis of the piston, It can be simply mounted. The guide band is an endless strand body having a ring structure in the mounted state but having two band end sections generally set in opposite directions to each other, and such an endless strand body is arranged around the piston body It can be placed simply. The two recessed flanks facing each other of the fixed recesses each have one undercut profile as viewed in cross section, wherein these recessed flanks each have a radial spacing relative to the recessed bottom of the fixed recess And has an annular fixed protrusion protruding in the direction of the recessed flank facing each other. The two fixed protrusions can be engaged with the side edge facing the guide band side which is pushed into the fixed recess, so that the guide band can be fixed in the radial direction of the piston in the shape-fitting manner.

The provision of the guide bands such that they can be resiliently deformed results in the fixing protrusions being able to be inserted into the respective side edges of the guide bands under localized deformation of the guide bands and forming a shape- An embodiment is particularly preferred. At this time, in the unmounted state, the guide band has a rectangular cross section in a preferable manner.

Alternatively, there is also the possibility that the guide band can be locked into the fixed recess or can implement the side edge of the guide band with an engaging structure that can be inserted in the form of a clip.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in more detail below with reference to the accompanying drawings.
1 shows a longitudinal section of a likewise preferred embodiment of a positioning device according to the invention in which a preferred embodiment of a piston according to the invention is mounted,
Fig. 2 is an enlarged view of a cross section II of the piston surrounded by the one-dot chain line in Fig. 1, in which case the cutting plane corresponds to the cutting line II-II shown in Figs. 4 and 5,
Figure 3 shows a cross section of a piston cut along the line III-III in Figure 1, in which case the remaining components of the positioning device are not shown, and in this case not only the guide band but also the magnet band Quot;
Figure 4 shows a side view of the piston viewed in the radial direction according to arrow IV of Figure 2, in which the cross-section enclosed by the one-dot chain line is further enlarged and in this case the guide band is not shown for better clarity , And
Fig. 5 shows another radial view of the piston in the viewing direction according to arrow IV, in an illustrative manner corresponding to Fig. 4, in which case the guide band is shown with the guide band mounted.

1 shows a longitudinal section of a positioning device 1 which can be actuated by a fluid, in one embodiment as a fluid actuated linear drive device 1a. However, the field of use of the present invention is not limited to linear actuators, but rather extends to all other types of positioning devices that can be used in connection with fluid applications, and consequently also for use in shock absorbers .

The positioning device 1 has a housing 2 defining a housing chamber 3 having a linearly extending and preferably circular cross section in which a piston 4 And is arranged so as to reciprocate linearly. The longitudinal axis 5 of the piston 4 travels in the direction of movement of the piston 4 and preferably coincides with the longitudinal axis 6 of the housing chamber 3. [

The housing chamber 3 is closed by a respective blocking wall 7a, 7b of the housing 2 at both front faces. The circumferential restriction on the outside of the radial direction of the housing chamber 3 supports a tube body 8 which extends between the two blocking walls 7a and 7b and is composed of one part or several parts, Defines a cylindrical piston running surface (9). The blocking walls 7a and 7b are formed as a separate housing cover against the tube body 8 in a preferred manner and are connected to the tube body 8 by fastening means. However, there is also the possibility that one or more blocking walls 7a, 7b can be formed integrally with the tube body 8.

The radial outer contour of the piston 4 is matched to the inner contour of the housing chamber 3, so that the piston slides along the piston running surface 9 when performing a linear movement. Preferably, a cylindrical guide surface 10 is mounted on the outer periphery of the radially oriented piston 4, which is slidably abutted against the piston running surface 9, The piston 4 experiences a linear guide with respect to the housing 2 due to the interaction between the guide surface 10 and the piston running surface 9 during linear motion.

By means of the piston 4 the housing chamber 3 is subdivided into two working spaces 12a and 12b in the axial direction and one fluid channel each lying outside the cutting plane of Figure 1 into these working spaces As a result, the fluid supply to the two work spaces 12a and 12b can be controlled as a result. In this way, the piston 4 can be driven in the axial direction of the longitudinal axis 6 for linear movement relative to the housing 2.

The fluid used for the operation of the positioning device 1 is preferably compressed air. However, other gas-type media or hydraulic media may be used.

The linear movement of the piston 4 can be branched out of the housing 2 at the power branching part 14 which is in motion with the piston 4. In this embodiment, the power branching portion is fixed to the piston 4 by a section of the blocking wall which is slidably passed through at least one blocking wall 7b in the sealed state and is placed inside the housing chamber 3 Which is a piston rod 15. Thus, the piston (4) and the piston rod (5) form one motion unit.

In one embodiment not shown in the drawing, the linear drive device 1a is a device in which the piston 4 is driven by a piston (not shown) magnetically coupled with a power branch portion movably supported outside the housing 2, for example, It is a linear drive without load.

The piston (4) preferably has a disk-shaped piston body (16). The piston body (16) has a piston body-radial plane (16a) perpendicular to the longitudinal axis (5) of the piston (4). In this embodiment, the piston 4 is fixed to the piston rod 15 through the piston body 16. [ Illustratively, the piston body 16 is formed in a disc shape and is penetrated by a center fixing hole 17 for attaching the piston body onto the piston rod 15. [

The piston body 16 is an integral part in the preferred manner. The piston body is preferably made of a rigid material, in this embodiment made from metal, especially aluminum die castings. As an alternative material for the piston body 16, for example, ceramic, glass or hard plastic may be mentioned, in which case composite materials are also possible.

The piston body 16 supports sealing means 18 concentric with the longitudinal axis 5 in its outer peripheral region and these sealing means ensure that the piston 4, And is brought into sliding contact with the running surface (9). These sealing means prevent fluids from overflowing between the two working spaces 12a, 12b. Illustratively, the sealing means 18 consists of two sealing rings 18a, 18b secured to the piston body 16 axially spaced relative to one another. Each of the seal rings 18a and 18b is preferably fixed inside the fixed grooves 19a and 19b opened radially outward and these fixed grooves are formed in the piston body 16 around the radially outer periphery of the piston body Respectively. Each of the fixed grooves 19a, 19b is arranged coaxially with respect to the longitudinal axis 5.

The guide surface 10 is formed by a radially outwardly directed outer circumferential surface of a guide band 22 having a ring structure in a preferred manner, which is in contact with the piston body 16 Is fixed. The piston body 16 has an annular fixed recess 23 coaxial with the longitudinal axis 5 in the region of its radially outer periphery and into which the guide band 22 extends radially And a guide band 22 is fixed inside the fixed recess.

In a preferred manner, the piston 4 is fitted with a permanent magnet assembly 24 which can be used for positional detection of the piston 4. The permanent magnet assembly 24 is firmly fixed to the piston 4 and makes linear motion of the piston together. Is positioned next to the motion path of the permanent magnet assembly 24 and in this case in particular outside the housing chamber 3 and which is not shown in the figure and which is responsive to the magnetic field of the permanent magnet assembly 24, The current axial position of the piston 4 supporting the permanent magnet assembly 24 during operation of the positioning device 1 can be determined. The position detection means may include, for example, one or more sensors, for example hole-sensors, or the position detection means may belong to the path measurement system.

The permanent magnet assembly 24 has an annular structure in a preferred manner and is disposed on the piston body 16 coaxially with respect to the longitudinal axis 5. [

In the corresponding configuration of the piston body 16, it is possible to arrange the guide band 22 and the permanent magnet assembly 24 in the axial direction in the piston body 16 in combination with one or more guide bands 22 . The permanent magnet assembly 24 is arranged at the same axial height as the guide band 22, and in particular, the permanent magnet assembly 24 is arranged at the same axial height as the guide band 22 for the structure of the piston 4 having a narrow width. In such a manner as to be concentrically surrounded by the above- The latter arrangement corresponds to this embodiment.

The permanent magnet assembly 24 is received within an annular receiving groove 25 of the piston body 16 formed in the region of the radially outer periphery of the piston body 16. The receiving groove 25 has a slot-like groove opening 26 extending in a ring shape around the piston body 16, which is directed radially outward, and the slot- The width is narrower than the fixed recess 23 when viewed in the axial direction. The receiving groove 25 is radially outwardly surrounded by the fixed recess 23. In this case the groove opening 26 of the receiving groove communicates with the interior of the recessed bottom 27 of the fixed recess 23. [ As the recess bottom 27, the radial bottom surface of the fixed recess 23 is used.

Preferably, the radially oriented groove opening 26 of the receiving groove 25 communicates with the interior of the stationary recess 23 in the axial central region. In this manner, one annular recess bottom section 27a, 27b, preferably having a cylindrical outer contour, is axially connected to both sides of the groove opening 26. [

The guide bands 22 disposed in the fixed recesses 23 cover the groove openings 26 and consequently also cover the permanent magnet assemblies 24 disposed in the receiving grooves 25.

The fixed recesses 23 for the guide bands 22 are provided with two lateral recess flank 28a and 28b which are spaced apart from each other in the axial direction of the longitudinal axis 5 of the piston 4 and facing each other. Each of these recess flanks 28 is connected to a recess bottom 27 which in this case illustratively shows that each recess flange 28a and 28b is formed by a pair of recessed bottom sections 27a and 27b Section. The fixed recess 23 is open at the radial direction side opposite to the recess bottom 27, that is, outside the radial direction.

The receiving groove 25 for the permanent magnet assembly 24 is referred to as the groove bottom 32 and is directed radially outward and has a groove bottom surface in which the groove opening 26 is facing radially outward.

The diameter of the groove bottom 32 is smaller than the diameter of the recess bottom 27.

The receiving grooves 25 have two lateral groove flanks 33a and 33b which are spaced apart from each other in the axial direction of the longitudinal axis 5 and at the same time facing each other, Will also be referred to as a first groove flank 33a and a second groove flank 33b. In this embodiment, the two groove flanks 33a and 33b extend in the radial direction to the recess bottom 27 of the fixed recess 23. The inner spacing of the two groove flank 33a and 33b is smaller than the inner spacing of the two recess flanks 28a and 28b. The receiving groove 25 preferably has at least a substantially rectangular cross-section.

The guide band 22 has a ring structure in a state of being fixed in the fixed recess 23. [ However, the ring structure is not completely closed on its own, but rather has a stop 34. Preferably, as the guide band 22, a strand body having two band end sections 22a, 22b set opposite to each other and having an infinite length is used. Preferably, the guide band is manufactured as a linear strand body that is bent into a ring shape after assembly when assembled in the piston body 16. The manufacturing in this manner is advantageous by having the characteristic that the guide band 22 can be elastically deformed.

In the assembled state, the guide band 22 is coaxially inserted into the fixed sleeve 23 while wrapping around the piston body 16. In this case, the band end sections 22a, 22b of the guide band are inserted into the fixed recess 23, (23a) in the circumferential direction (23). The circumferential direction 23a of the fixed recess 23 is in the direction about the longitudinal axis 5 and is indicated by a double arrow in Fig.

In a preferred manner, between the two band end sections 22a, 22b, there is a small gap defining at least the intermediate portion 34.

The front surfaces of the guide bands 22 facing each other in the circumferential direction of the fixed recess 23 are preferably inclined over the entire width of the guide band 22. [ In this case, the inclined front surfaces facing each other of the two band end sections 22a, 22b preferably proceed parallel to each other.

The permanent magnet assembly 24 consists of a permanent permanent magnet magnet band 35, preferably curved in a ring structure. The magnet bands 35 have an infinite length in a preferred manner and have two band end sections 35a, 35b set in opposite directions. Preferably, the magnet band 35 is fabricated as a linear strand body which bends into a ring structure when mounted in the receiving groove 25. [ In other words, the magnet band 35 is radially inserted into the receiving groove 25 and bent around the piston body 16 in a preferred manner when assembled to the piston body 16. Such an assembling method preferably corresponds to a method of assembling the guide band 22. [

Such an assembling method is advantageous in that the assembling band 35 is elastically deformable. Preferably, the assembly band consists of a strand-shaped band body made of elastically deformable plastic material, provided with permanent magnet means responsible for the permanent magnetism characteristics of the magnet band 35. As the permanent magnet means, for example, ferromagnetic particles which are magnetized after being buried in a minute distribution in a strand-shaped band body at the time of manufacturing a magnet band are used.

The two band end sections 35a and 35b are directed toward each other in the circumferential direction 25a of the receiving groove 25 when the magnet band 35 is inserted into the receiving groove 25 in a state in which the magnet band 35 is used. The circumferential direction 25a of the receiving groove 25 is in the direction around the longitudinal axis 5 and is indicated by a double arrow in Fig. Between the two band end sections 35a and 35b there is in particular a ring structure recess 36 of the magnet band 35 which appears in a small intermediate space so that the two band end sections 35a, They are opposed to each other with a small gap in the circumferential direction 25a of the groove 25. [ The circumferential direction 25a of the receiving groove 25 is the direction around the longitudinal axis 5 of the piston 4. [

The magnet bands have two longitudinal side faces 39a and 39b facing the one groove flank of the groove flank 33a and 33b, respectively, in the state of being mounted in the receiving groove 25. [

The tendency of the guide band 22 to expand in the region of the two band end sections 22a and 22b and to release from the fixed recess 23 due to its elastic property in the state where it is inserted into the fixed recess 23 The guide bands 22 are fixed only by the piston body 16 due to the desired anchoring action and consequently the guide bands maintain their ring structure and in such a ring structure, And is fixed in the fixed recess 23 over a long length.

Corresponding contents are applied in relation to the receiving groove 25 with respect to the magnet band 35 in a preferred manner. In the region of the receiving groove 25 of the piston body 16, the piston body fixes the magnet band 35 inserted into the receiving groove 25, so that, despite the enlargement tendency based on its own elasticity, Is disposed in the receiving groove 25 over a length and is formed so as not to be unfolded in the region of the two band end sections 35a and 35b.

The effect described herein is characterized in that in the guide band 22, the two recessed flank 28a, 28b of the fixed recess 23 each have an undercut profile when viewed in cross-section, The recessed flank 28a and 28b are formed by mutually facing side edges 37a and 37b of the two side edges 37a and 37b of the guide band 22 oriented in the axial direction of the longitudinal axis 5, . &Lt; / RTI > As a result of the geometrical coupling acting in the radial direction with respect to the longitudinal axis 5, the guide band 22 is thus guided by its profiled recess blanks 28a, 28b in its fixed length 23 And is firmly fixed. In a preferred manner, disengagementable shape-engaging engagement is dealt with in order to enable exchange of guide bands when necessary.

The undercut profile of the recessed flank 28a and 28b appears within the fixed protrusions 38a and 38b projecting in the direction of the recessed flank 28b and 28a which are particularly opposed to the respective recessed flank 28a and 28b, The fixed projection is disposed concentrically with respect to the longitudinal axis 5 of the piston 4 and extends without interruption in the circumferential direction 23a of the fixed recess 23. [ Each of the two fixing projections 38a and 38b is disposed radially spaced apart from the recess bottom 27 of the fixed recess 23 with respect to the longitudinal axis 5, In the region of the individual recess flank 28a, 28b lying radially between the recessed bottom 27 and the fixed recesses 43a, 43b annularly closed by itself, ring-shaped recesses 43a, 43b appear, A guide band (22) can be inserted in the seth, which is also arranged concentrically with respect to the longitudinal axis (5) of the piston (4).

Preferably, the guide band 22 has a rectangular cross section in the starting state, which is not yet inserted into the stationary recess 23. In this starting condition, the width of the guide band 22 is slightly larger than the inner spacing of the fixed projections 38a, 38b, which are measured in the axial direction of the longitudinal axis 5, facing each other. In this manner, the fixing projections 38a and 38b can be fixed to the associated side edges 37a and 37b under the local deformation of the guide band 22, respectively, with the guide band 22 inserted into the fixing recess 23. [ , 37b, respectively. The material of the guide band 22 pushed by the insert engages the interior of the fixed recesses 43a and 43b. According to this method, a shape coupling portion acting in the radial direction of the piston 4 is shown between the piston body 16 and the guide band 22, To be secured by the undercut profile of the recessed flank 28a, 28b at the two side edges 37a, 37b over the entire length.

When the guide band 22 is assembled, a force in the radial direction with respect to the longitudinal axis 5 acts on the guide band, so that the guide band is inserted between the two fixing projections 38a and 38b and tightly clamped therein.

There is a possibility that the guide band 22 has a pre-formed joining contour on its two lateral edges 37a, 37b, thereby enhancing the shape coupling effect, in which case the pre- As a result of having a profile complementary to the ringed recess flank 28a, 28b, the guide band 22 can thus be locked within the fixed recess 23 over its entire length, have.

In order to secure the magnet bands 35, it is preferred that the magnet bands 35 are not tightly clamped by the piston body 16 over their entire length, but rather only in some areas and, The clamping principle, which is tightly clamped only in the two band end sections 35a, 35b, is used. Clamping fixation of the two band end sections 35a, 35b is made independently of each other. The two band end sections 35a, 35b are not mutually fixed but rather only fixed to the piston body 16, respectively.

The piston body 16 has a clamping area 44 at one or more points around its perimeter periphery in which the piston body 16 has two band end sections 35a and 35b And is formed so as to be clamped in the receiving grooves 25 independently of each other by a clamping method. In this case, the piston body 16 has two clamping zones 45a, 45b adjacent to each other in the circumferential direction 25a of the receiving groove 25 in the clamping zone 44, And one of the sections 35a and 35b is formed to be fixed in a forced engagement manner.

The magnet band 35 has a constant width "B" in a preferred manner over its entire length. This width B was measured in the axial direction of the longitudinal axis 5 of the piston 4 or between two side surfaces 39a and 39b. In addition, the magnet bands 35 have a rectangular cross-sectional shape in a preferred manner.

The width B of the magnet band 35 is smaller than the inner spacing Al of the two groove flank 33a and 33b of the receiving groove 25. [ The magnet band 35 is accommodated in the receiving groove 25 with a slight play in the region of the receiving groove 25 in which the sections of the groove flank 33a and 33b are opposed have.

Alternatively, the piston body 16 is mounted in the region of the two clamping zones 45a, 45b in the direction of the groove flank 33a, 33b, respectively, which are opposed to one of the two groove flank 33a, 33b (46a, 47a; 46b, 47b) projecting therefrom, which causes localized stenosis of the receiving groove (25). Due to local stenosis, the magnet band 35 can not be deployed because it is tightly clamped in the receiving groove 25 at one or more points in the region of its two band end sections 35a, 35b. The stenotic zone, which may also be referred to as a narrow point, is indicated by the arrow in (48).

There is the possibility of providing only one clamping projection in each clamping section 45a, 45b, in which case the spacing of the clamping protrusions relative to the opposing groove flanks is greater than the width B of the magnet band 35 So that the clamping condition results substantially from the situation where only one clamping projection is inserted into the side surfaces 39a and 39b facing the magnet band 35. [

There is a possibility that a plurality of clamping projections in each clamping zone 45a, 45b can be spaced apart from each other in the circumferential direction 25a of the receiving groove 25. For example, in this case, the plurality of clamping protrusions may be formed in the same and in the same case in the same groove flank 33a, 33b.

The possibility of providing two clamping protrusions 33a and 33b on one or two clamping zones 45a and 45b with two clamping protrusions facing each other in the axial direction of the longitudinal axis 5 of the piston 4 And in which case these groove flanks define a narrow place 48 for projecting against each other to clamp the associated band end sections 35a, 35b. In this case, there may be only one pair or a plurality of pairs of clamping protrusions facing each other as described above for the clamping sections 45a, 45b.

Particularly preferred forms of the two clamping zones 45a, 45b have been implemented in the embodiment and are shown in the figures. The piston body 16 is provided with a plurality of clamping protrusions 46a, 47a, 47a, 45a, 45a arranged in spaced relation to each other in the circumferential direction 25a of the receiving groove 25, in each of the two clamping zones 45a, 45b. 46b, 47b, that is, a plurality of clamping projections which are displaced with respect to each other in the circumferential direction of the accommodating groove 25. [ However, the clamping protrusions 46a, 47a, 46b, 47b are not located in the same groove flank 33a, 33b in the respective clamping zones 45a, 45b, but rather are arranged in different groove flanks 33a, 33b . Illustratively, in each of the clamping zones 45a and 45b, the first clamping projections 46a and 46b are integrally formed in the first groove flange 33a and, in this regard, The second clamping protrusions 47a and 47b spaced in the direction 25a are formed integrally with the second groove flank 33b. There is preferably no clamping protrusion in the region where the individual clamping projections 46a, 47a, 46b, 47b of the respective different groove flank 33a, 33b are opposed, where the associated groove flank 33a, 33b is clamped And is formed in a shape without protrusions.

In this manner, within the receiving groove 25, a plurality of narrow points or stenosis areas 48 are shown, spaced apart from one another in the circumferential direction of the receiving groove 25, per clamping area 45a, 45b, These narrow points or narrowed regions are caused by the clamping protrusions 46a, 47a, 46b, 47b projecting into the receiving groove 25 from the groove flank 33a, 33b set opposite to each other.

In such an arrangement, the band end sections 35a, 35b pushed into the clamping sections 45a, 45b draw wave lines in the circumferential direction 25a of the receiving groove 25, Passes through the clamping areas 45a, 45b and thereby effectively clamps tightly. In this clamping method, the inner gap A2 measured between the respective clamping protrusions 46a, 47a; 46b, 47b and the opposing groove flank 33a, 33b is smaller than the width B of the magnet band 35, . Such an internal clearance A2 may preferably be the same size as the width B of the magnet band 35 or even slightly larger than the width B of the magnet band 35. The clamping effect is mainly achieved by tightening the magnet bands 35 by the groove flank 33a and 33b in the respective clamping areas 45a and 45b and in particular in the areas adjacent to the clamping protrusions 46a and 47a; As a result of being transformed into a cereal form.

In this case the clamping effect is crucially achieved by the fact that the band end sections 35a and 35b are forced by the clamping protrusions alternately present in the different groove flank 33a and 33b in the clamping sections 45a and 45b, Shaped or at least a curved longitudinal shape and has a tendency to be deformed inversely to its linear starting shape due to the elasticity of the magnet band 35, consequently in the receiving groove 25 in its circumferential direction 25a ) In the longitudinal direction.

In the individual clamping sections 45a and 45b two clamping projections 46a, 47a and 46b, spaced apart from each other in the circumferential direction 25a of the receiving groove 25, measured and projected in the longitudinal direction of the piston 4, And 47b are smaller than the width B of the magnet band.

Clamping protrusions 46a, 47a; 46b, 47b disposed in different groove flank 33a, 33b, measured in the circumferential direction of the receiving groove, in each clamping zone 45a, 45b, It is also preferable to select the interval A4 of the magnet bands to be at least as large as the width B of the magnet bands and at most twice as large as the width B of the magnet bands.

It has been found that by providing two clamping projections 46a, 47a, 46b, 47b per clamping zone 45a, 45b in order to reliably clamp the associated band end sections 35a, 35b in a reliable clamping manner It is already enough. However, more than two clamping protrusions may be provided per clamping zone.

It is also entirely sufficient to provide a single clamping area 44 of the type described above along the periphery of the receiving groove 25. The magnet band 35 is already firmly fixed in the receiving groove 25 when the magnet band 35 is fixed only on its own two band end sections 35a and 35b.

However, for the speed at which the piston 4 is assembled, another clamping area 44a of the above-described structure is provided at one or more points spaced relative to the clamping area 44 in the circumferential direction of the piston body 16 May be desirable. In this case, the further clamping area 44a is alternatively provided with two band sections (not shown) when the magnet band 35 is inserted into the receiving groove 25 at a corresponding position inside the clamping area 44 35a, 35b. In principle, the number of clamping areas is kept as low as possible, although more of the clamping areas as described above may be distributed along the circumference of the piston body 16, This is because it is basically difficult to insert the magnet bands 35.

The clamping protrusions 46a, 47a; 46b, 47b may basically be formed arbitrarily. Importantly, these clamping protrusions cause localized stenosis in the corrugation groove 25. Each of the clamping projections 46a, 47a, 46b, 47b is formed in a rib shape having an intuitive shape according to Figs. 2 and 3, starting from the region of the groove bottom 32 of the receiving groove 25 A molding extending in the direction of the radial groove opening 26 of the receiving groove 25 has been found to be particularly desirable. In such a relationship, among other things, the clamping protrusions 46a, 47a (46b, 47b) move radially outwardly toward their end regions towards the radial groove opening 26 and towards the associated groove flank 33a, 33b It is preferable that the inclined surface 49 is provided. The slope 49 forms an inclined guide surface which reliably guides the individual band end sections 35a and 35b, which are provided with a pressing force from outside in the radial direction, into the receiving groove 25 at the time of assembly.

Claims

As a piston for a positioning device which can be actuated by a fluid, in particular a fluid operated linear actuator,
Characterized in that the piston body has two lateral groove flanks (33a, 33b) which are coaxial with respect to the longitudinal axis (5) of the piston (4) and facing each other in the region of its radial outer periphery, 33b, and a permanent magnet assembly (24), which can be used for position detection in the receiving groove (25), is housed in the receiving groove (25)
Wherein the permanent magnet assembly (24) comprises a permanent magnet magnet band (35) of a resilient permanent magnet which is bent in a ring structure, the magnet band comprising two band end sections facing each other in the circumferential direction of the receiving groove Wherein the width of the magnet bands is smaller than the spacing between the two groove flanks of the receiving groove and the width of each of the two band end sections 35a and 35b Are clamped in clamping areas 45a and 45b of the receiving groove 25 adjacent to each other in the circumferential direction of the receiving groove 25 and in the clamping area the piston body 16 is fixed to the receiving groove One or more clamping protrusions 46a, 47a, 46b, 47b projecting against one groove out of the groove flank 33a, 33b under the local stenosis of the magnet band 35 and pressed against the sides 39a, 39b of the magnet band 35, ) It is a piston.

4. A device according to claim 1, characterized in that the piston body (16) comprises a plurality of clamping projections (46a, 47a; 46b, 47b) in each clamping section (45a, 45b) of the receiving groove (25) piston.

3. A method as claimed in claim 1 or 2, characterized in that the piston body (16) is arranged in each clamping area (45a, 45b) of the receiving groove (25) with a spacing to each other in the circumferential direction of the receiving groove , And a plurality of clamping projections (46a, 47a;

4. The clamping device according to claim 3, characterized in that the different groove flank (33a, 33b) in each clamping zone (45a, 45b) is provided with two or more clamping projections The clamping protrusions 46a and 47a and the clamping protrusions 46b and 47b on the groove flanks 33b and 33a are not in contact with the clamping protrusions 46a and 47a, , Piston.

5. A clamping device according to claim 4, characterized in that in the individual clamping sections (45a, 45b) two clamping projections (46a, 46b) spaced apart from each other in the circumferential direction of the receiving groove (25), measured and projected in the longitudinal direction of the piston 47a, 46b, 47b is smaller than the width (B) of the magnet band (35).

6. A method according to claim 4 or 5, characterized in that the internal spacing between the opposing groove flank (33a, 33b) of the receiving groove (25) and the individual clamping protrusions (46a, 47a; 46b, 47b) Is equal to or greater than the width (B) of the piston (12).

Clamping protrusions (46a, 47a; 46b) arranged in different groove flanks, measured in the circumferential direction of the receiving groove (25), in the individual clamping zones (45a, 45b) Characterized in that the distance A4 between the magnet bands 35 and 47b is at least equal in magnitude to the width B of the magnet band 35 and at most twice the width B of the magnet band 35, .

8. A device according to any one of the preceding claims, characterized in that precisely two clamping projections (46a, 47a; 46b, 47b) are arranged in each of the two clamping zones (45a, 45b) .

The clamping device according to any one of claims 1 to 8, wherein the clamping projections (46a, 47a; 46b, 47b) are each formed in a rib shape having a straight pipe shape, The clamping protrusions 46a, 47a; 46b, 47b extend from the area of the radial groove opening 26 toward the radial groove opening 26 of the receiving groove 25, Is inclined toward the associated groove flanks (33a, 33b) in the end region of the piston.

10. A device according to any one of the preceding claims, characterized in that the magnet bands (35) have a rectangular cross-section and / or the magnet bands (35) can be resiliently deformed and the permanent magnet means Characterized in that the piston has a strand-shaped band body made of a material.

11. A piston according to any one of the preceding claims, characterized in that the piston body (16) is made of a rigid material, preferably a metal.

12. A device according to any one of the preceding claims, characterized in that the piston body (16) has two clamping zones (45a, 45b) adjacent to each other in two peripheral zones, (44, 44a) for clamping the two band end sections (35a, 35b), characterized in that the two clamping zones (44, 44a) can alternatively be used for clamping of the two band end sections Piston.

13. A device according to any one of the preceding claims, characterized in that the annular receiving groove (25) is surrounded by an annular fixed recess (23) formed in the piston body (16) The groove opening 26 which is narrower than the recess 23 and lies outside the radial direction of the annular receiving groove communicates with the interior of the recessed bottom 27 of the fixed recess 23, Characterized in that an annular structured guide band (22) is fixed in the radial direction to cover the magnet band (35) radially outside.

14. A piston according to any one of the preceding claims, characterized in that in the region of the radially outer periphery of the piston body (16) there are two lateral recesses An annular fixed recess 23 having flanks 28a and 28b is formed and a guide band 22 having a ring structure is fixed in the fixed recess and the guide band is fixed to the fixed recess 23 , And two recessed flank (28a, 28b) of the fixed recess (23) are in the form of an undercut when viewed transversely Each of which has an annular fixed protrusion (not shown) protruding in the direction of the opposing recess flank 28a, 28b with a gap in the radial direction with respect to the recess bottom 27 of the fixed recess 23 38a, 38b), and the fixed projection DE 22 side toward the side edges (37a, 37b), and a piston, characterized in that engaging into the image combining method.

15. A method according to claim 14, characterized in that the fixing projections (38a, 38b) are formed under the local deformation of the guide band (22) and in the inside of the respective side edges (37a, 37b) of the guide band (22) Characterized in that the guide band (22) has a rectangular cross-section in a preferred manner in a starting condition not yet mounted in the stationary recess (23).

1. A linear drive device, in particular a fluid operated, which can be actuated by a fluid, comprising a housing (2) in which a piston (4)
Characterized in that the piston (4) is formed according to any one of claims 1 to 15.