Mounting device for attaching a position sensor to a rod-shaped actuator

Abstract

The invention relates to a fastening device which is designed to fasten a position sensor to a rod-shaped actuator, comprising two fastening profiles which can be moved back and forth in a clamping direction and which each have a constant cross-section in a profile longitudinal direction, alignment means which point towards one another in the clamping direction and which engage in a guiding manner, and clamping regions which point towards one another in the clamping direction, wherein the clamping regions are designed to receive the actuator between them in a clamping position, fastening means which are designed to lock the fastening profiles in a clamping position in which the clamping surfaces receive the actuator between them in a clamping position, and a position sensor mounting section which is formed on one of the fastening profiles and is designed for mounting a position sensor.

Description

The invention relates to a fastening device which is designed to fasten a position transmitter to a rod-shaped actuator.Position sensors which are designed to detect an actual position of a rod-shaped actuator and for this purpose have to be fastened to the corresponding actuator are fundamentally known in the prior art. The actuator can be a push rod, by means of which a drive, for example a pneumatic drive, is connected to a closing body interacting with a valve seat. The actual position detected by the position transmitter is transmitted to a controller unit and compared there with a desired position. Depending on a deviation of the actual position from the desired position, an actuating signal for controlling the drive is then generated in the controller unit.From the utility model specification DE 20 2017 100 231 U1 a fastening device for fastening a sensor to a rod-shaped object is known. The fastening device has two fastening parts, between which the rod-shaped object is fixed. A first receiving part has a receiving part which is adapted to the contour of the rod-shaped object. The fastening parts are fastened to one another by means of a screw.The patent specification DE 102017 126 008 B4 discloses a holding device for arranging a sensor having a first and a second holding jaw which are arranged opposite one another. A first tube is arranged on the first holding jaw and a second tube on the second holding jaw. The second tube is accommodated in the first tube, so that the retaining jaws are movable relative to one another via a clamping means.DE 10 2007 019 610 A1 discloses a device for fastening a measurement or display unit to an object, which device has an elongate guide element on which an alignment aid and a holder are arranged such that they can be displaced in the longitudinal direction of the guide element. The alignment aid and the holder are displaceable relative to one another in such a way that the object is held in a clamping manner. Furthermore, the device has a post-clamping device, with which the measuring or display unit can be pressed against the object with a defined pressing force.For the fastening of a position transmitter to a rod-shaped actuator, a fastening device 100 is known, for example, which is shown in FIGS. 18 and 19 and has an L-shaped mounting plate 101 and two U-shaped clamping brackets 102 which can be fastened to the mounting plate 101. One of the mounting plate sections 103 arranged perpendicular to one another, which serves for fastening the mounting plate 101 to a rod-shaped actuator 104, comprises a clamping region 105 which is recessed in a channel-like manner and forms a clamping surface 1 and has two sections 106 inclined in a prism-like manner to one another, and is provided with four bore holes 107, through which the free ends of the clamping brackets 102 can be passed. The other mounting plate section 108 forms a position transmitter mounting section and is formed with two elongated holes 109 through which fastening screws, not shown in detail, can be guided for fastening a position transmitter. The clamping brackets 102 are provided with external threads 110 at their free ends so that they can be mounted to the mounting plate portion 103 with the aid of nuts 111.A problem in mounting the fastening device 100 shown in FIGS. 18 and 19 on an actuator 104 is that the mounting plate 101 with the position transmitter fastened thereto and the clamping brackets 102 must be held and the nuts 111 must be screwed onto the clamping brackets 102, which is very difficult to design and requires much manual skill. Furthermore, the assembler must grasp the region of the moving parts of the thrust drive, which entails a certain risk of injury.Proceeding from this prior art, it is an object of the present invention to provide a fastening device of the type mentioned at the beginning with an alternative structure.To achieve this object, the present invention provides a fastening device which is designed to fasten a position transmitter to a rod-shaped actuator, comprising two fastening profiles which can be moved back and forth in a clamping direction and each have a constant cross section in a profile longitudinal direction, alignment means which point toward one another in the clamping direction and engage one another in a guiding manner and clamping regions which point toward one another in the clamping direction, wherein the clamping regions are designed to receive the actuator between them in a clamping manner, fastening means which are designed to lock the fastening profiles in a clamping position in which the clamping surfaces receive the actuator between them in a clamping manner, and a position transmitter mounting portion which is designed to mount a position transmitter and is designed on one of the fastening profiles. Thanks to the interlocking fastening profiles, the fastening devices according to the invention can be handled very easily, so that time and costs are saved during assembly. Furthermore, the fastening profiles prevent the assembler from engaging in the region of the moving parts of the thrust drive, whereby the risk of injury is minimized.Preferably, the fastening profiles, when viewed from their end face, have webs and recesses which project in the clamping direction and form the alignment means, wherein the webs engage positively in the recesses. In this way, a simple and inexpensive construction is achieved.Preferably, at least one of the clamping regions, viewing the corresponding fastening profile from its end face, has a clamping surface pointing towards the opposite fastening profile with a ring segment-shaped, in particular ring segment-shaped, cross section.Advantageously, at least one of the clamping regions, viewing the corresponding fastening profile from its end face, has a clamping surface facing the opposite fastening profile with a cross section which comprises two sections inclined in prism-like manner with respect to one another.According to one embodiment of the present invention, screw sets comprising a bolt and a nut, preferably a washer, are provided as fastening means, the screws of which screw sets extend in the clamping direction and are arranged at a distance from one another in the profile longitudinal direction.One of the fastening profiles advantageously has a T-groove which receives the heads of the screws in a rotationally fixed manner, and the other fastening profile is provided with apertures which receive the screw shanks and which are in particular formed as bores. In particular, the T-groove further facilitates the handling of the fastening device according to the invention, since the holding of the screws is significantly simplified.The position transmitter mounting section is preferably formed on a side of the fastening profile facing away from the clamping region, so that the position transmitter is not disruptive when mounting the fastening device on the actuator.The position transducer mounting section, looking at the fastening profile from its end face, is advantageously formed by a web extending in the clamping direction, which web is provided in particular with mounting openings for passing fastening screws through, of which preferably at least one is formed as an elongated hole.Advantageously, the fastening profiles are made of metal, in particular of aluminum.Furthermore, the present invention proposes using a fastening device according to the invention for fastening a position transmitter to a rod-shaped actuator, wherein the position transmitter is designed to detect an actual position of the actuator.Other features and advantages of the present invention will become apparent from the following description with reference to the accompanying drawings, in which FIG. 1 is a perspective view of a fastening device according to an embodiment of the present invention; FIG. 2 shows a first end view of the fastening device shown in FIG. 1 ; FIG. 3 shows a second end view of the fastening device shown in FIG. 1 ; FIG. 4 is a first side view of the fastening device shown in FIG. 1 ; FIG. 5 is a second side view of the fastening device shown in FIG. 1 ; FIG. 6 shows a perspective view of a first fastening profile of the fastening device shown in FIG. 1 ; FIG. 7 shows a first end side view of the fastening profile shown in FIG. 6 ; FIG. 8 shows a second end view of the fastening profile shown in FIG. 6 ; FIG. 9 shows a first side view of the fastening profile shown in FIG. 6 ; FIG. 10 shows a second side view of the fastening profile shown in FIG. 6 ; FIG. 11 is a perspective view of a second fastening profile of the fastening device shown in FIG. 1 ; FIG. 12 shows a first end view of the fastening profile shown in FIG. 11 ; FIG. 13 shows a second end view of the fastening profile shown in FIG. 11 ; FIG. 14 shows a first side view of the fastening profile shown in FIG. 11 ; FIG. 15 shows a second side view of the fastening profile shown in FIG. 11 ; FIG. 16 is a perspective view of the fixing device shown in FIG. 1 in a state in which it is fixed to an actuator; FIG. 17 is an end view of a fastening device according to a second embodiment of the present invention; FIG. 18 is a perspective view of a conventional fixing device in a state of being fixed to an actuator; and FIG. 19 is a side view of the fastening device shown in FIG. 18.In the drawing, like reference numerals designate like or like components.FIGS. 1 to 16 show a fastening device 1 according to an embodiment of the present invention or components thereof. This is designed to fasten a position transducer, not shown in more detail, to a rod-shaped actuator, such as, for example, to a push rod of a pneumatic thrust drive of a valve. The fastening device 1 comprises as main components two fastening profiles 2 and 3 movable back and forth in a clamping direction K and fastening means 4, in the present case in the form of two screw sets, which are designed to lock the fastening profiles in a clamping position.The fastening profiles 2 and 3 are produced from metal, in the present case from aluminum, and each have a constant cross section in a profile longitudinal direction L, apart from apertures. They are provided in the clamping direction K with mutually facing and guidingly intermeshing alignment means 5. More precisely, the fastening profiles 2 and 3, when viewed from their end face, have webs 6 protruding in the clamping direction K and recesses 7, which form the alignment means 5, wherein the webs 6 engage positively in the recesses 7. Furthermore, the fastening profiles 2 and 3 comprise clamping regions 8 and 9 pointing towards one another in the clamping direction K, wherein the clamping regions 8 and 9 are designed to receive the actuator between them in a clamping manner. In the present case, both clamping regions 8 and 9, which point out the corresponding fastening profiles 2 and 3 from their end face, have a clamping surface 10, 11 pointing toward the opposite fastening profile and having a ring segment-shaped, in particular circular ring segment-shaped, cross section. On the fastening profile 2, a position transmitter mounting section 12 designed for mounting a position transmitter is formed. The position transmitter mounting section 12 is formed in the present case on a side of the fastening profile 2 facing away from the clamping region 8 and, looking at the fastening profile 2 from its end side, is formed by a web 13 extending in the clamping direction K, which web is provided with mounting openings 14 for passing fastening screws, not shown in detail in the present case, which are formed in the present case as elongated holes.The fastening means 4 designed as screw fittings serve to lock the fastening profiles 2 and 3 in a clamping position in which the clamping surfaces 10 and 11 receive the actuator between them in a clamping manner. They each have a screw 14, a nut 16 and a washer 16. The screws 14 each extend in the clamping direction K and are arranged at a distance from one another in the profile longitudinal direction L. For the rotationally fixed reception of the heads of the screws One of the fastening profiles, one of the fastening profiles, which one receives the heads of the screws 14, the fastening profile 2 is provided on its side facing the fastening profile 3 with a T-groove 18 extending in the profile longitudinal direction L, and the fastening profile 3 is provided with apertures 19 which receive the screw shafts and which are designed in the present case as bores.In order to mount the fastening device 1 on an actuator, in a first step a position transmitter is mounted on the position transmitter mounting section 12 using suitable fastening screws. Then the nuts 16 of the fastening means 4 are loosened and the fastening profiles 2 and 3 are moved away from each other such that a gap 20 present between the free ends of the clamping regions 8 and 9 is wider than the diameter D of the actuator. Now the actuator is introduced through the gap 20, whereupon the fastening profiles 2 and 3 are manually compressed and moved towards each other and subsequently the nuts 16 are tightened again until the actuator is clampingly held between the clamping surfaces 10 and 11 of the clamping areas 8 and 9. The fastening device 1 has the advantage that it can be held with one hand during assembly, so that the nuts 16 can be easily tightened with the other hand. Moreover, none of the hands must grasp the area of the moving parts of the thrust drive. Accordingly, the fastening device can be installed quickly, easily and securely.FIG. 17 shows an alternative embodiment according to the invention of the clamping regions 8 and 9. the clamping region 8 of the fastening profile 2 has, as viewed from its end face, a clamping surface 10 pointing towards the opposite fastening profile 3 and having a cross section which comprises two sections 21 inclined in the manner of prisms with respect to one another. The clamping region 9 of the fastening profile 3, on the other hand, has a planar clamping surface 11. Otherwise, the fastening device 1 shown in FIG. 17 corresponds to the fastening device 1 shown in FIG. 1.Although the invention has been illustrated and described in more detail by the preferred exemplary embodiment, the invention is not restricted by the disclosed examples and other variations can be derived therefrom by the person skilled in the art without departing from the scope of protection of the invention.Regardless of the grammatical sex of a certain term, individuals with male, female or other sex identity are included.

Claims

Fastening device (1) designed to fasten a position transmitter to a rod-shaped actuator, comprising two fastening profiles (2, 3) which can be moved back and forth in a clamping direction (K) and each have a constant cross section in a profile longitudinal direction (L), alignment means (5) pointing towards one another in the clamping direction (K) and guidingly engaging one another and clamping regions (8, 9) pointing towards one another in the clamping direction (K), wherein the clamping regions (8, 9) are designed to receive the actuator between them in a clamping manner, fastening means (4) which are designed to lock the fastening profiles (2, 3) in a clamping position in which the clamping surfaces (10, 11) receive the actuator between them in a clamping manner, and a position transmitter mounting portion (12) which is designed to mount a position transmitter and is designed to one of the fastening profiles (2, 3).Fastening device (1) according to claim 1, characterised in that the fastening profiles (2, 3), when viewed from their end face, have webs (6) projecting in the clamping direction (K) and recesses (7) which form the alignment means (5), wherein the webs (6) engage in the recesses (7) in a positive-locking manner.Fastening device (1) according to claim 1 or 2, characterised in that at least one of the clamping regions (8, 9), looking at the corresponding fastening profile (2, 3) from its end face, has a clamping surface (10, 11) pointing towards the opposite fastening profile (3, 2) with a ring segment-shaped, in particular ring segment-shaped, cross-section.Fastening device (1) according to claim 1 or 2, characterised in that at least one of the clamping regions (8, 9), looking at the corresponding fastening profile (2, 3) from its end face, has a clamping surface (10, 11) pointing towards the opposite fastening profile (3, 2) with a cross-section which comprises two sections (21) inclined in prism-like manner with respect to one another.Fastening device (1) according to one of the preceding claims, characterized in that screw sets comprising a screw (14) and a nut (16) are provided in each case as fastening means (4), the screws (14) of said screw sets extending in the clamping direction (K) and being arranged at a distance from one another in the profile longitudinal direction (L).Fastening device (1) according to Claim 5, characterized in that one of the fastening profiles (2, 3) has a T-groove (18) which receives the heads of the screws (14) in a rotationally fixed manner, and the other fastening profile (3, 2) is provided with apertures (19) which receive the screw shafts.Fastening device (1) according to one of the preceding claims, characterized in that the position transmitter mounting section (12) is formed on a side of the fastening profile (2) facing away from the clamping region (8).Fastening device (1) according to one of the preceding claims, characterized in that the position transmitter mounting section (12), looking at the fastening profile (2) from its end face, is formed by a web (13) extending in the clamping direction (K).Fastening device (1) according to Claim 8, characterized in that the web (13) extending in the clamping direction (K) is provided with mounting openings (14) for the passage of fastening screws.Fastening device (1) according to one of the preceding claims, characterized in that the fastening profiles (2, 3) are produced from metal.Use of a fastening device (1) according to one of the preceding claims for fastening a position transmitter to a rod-shaped actuator, wherein the position transmitter is designed to detect an actual position of the actuator.

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