CN101157211A - Hydraulic tensioning device - Google Patents

Abstract

The invention relates to a hydraulic tensioning device having a hydraulic piston (13) acted upon by a hydraulic medium, wherein the hydraulic piston (13) transmits the tensioning force exerted on the hydraulic piston (13) via an intermediate component (14) To the end (20) of the bolt (11) to be tensioned, and wherein the hydraulic piston (13) and intermediate member (14) are surrounded by a housing (15). According to the invention, said tension transmitting intermediate member (14) is screwed at the first end (18) with the hydraulic piston (13) and at the second end (19) with the bolt (11), Wherein adjacent to the first end (18) of the intermediate member (14) the housing (15) is provided with a constriction (21) and adjacent to the second end (19) of the intermediate member (14) The housing (15) is provided with positioning pins (22) embedded in grooves (23) of the intermediate member (14).

Description

hydraulic tensioner

technical field

The invention relates to a hydraulic tensioning device according to the preamble of claim 1 .

Background technique

DE4341707C3 discloses a hydraulic bolt tensioning device which has a hydraulic piston which is surrounded by a cylindrical housing. The hydraulic piston is acted upon by a hydraulic medium to provide a pressure or tension force on the hydraulic piston, which can be transmitted to the bolt to be tensioned via an intermediate component. According to DE4341707C3, the intermediate component is configured as a threaded sleeve. The threaded sleeve is screwed to the end of the stud to be tensioned. Then, when the threaded sleeve breaks off, the lower part of the threaded sleeve remains on the piston, and the upper part of the threaded sleeve is prevented from being thrown off by the cover. When the threaded sleeve breaks off, the hydraulic piston is fixed on the lower end of the threaded sleeve through the tapered surface. This measure prevents the broken part from being thrown off when the threaded sleeve breaks off.

Contents of the invention

Proceeding from this, the object of the present invention is to provide a novel hydraulic tensioning device with snap-off protection. This task is achieved by a hydraulic tensioning device according to claim 1 . According to the invention, the tension-transmitting intermediate member is screwed at a first end to a hydraulic piston and at a second end to a screw, wherein the housing is provided adjacent to the first end of the intermediate member. There is a constriction, and adjacent to the second end of the intermediate member, the housing is provided with a locating pin that engages in a groove of the intermediate member.

In the hydraulic tensioning device according to the invention, the protection against breaking can be realized with relatively simple structural means. No special safety device is required in order to prevent the parts from flying off in the event of breakage of the intermediate member or the hydraulic piston.

According to an advantageous development of the invention, the housing has a preferably cylindrical housing section surrounding the hydraulic piston and the intermediate component, and a cover plate, wherein the cover plate is fastened to the housing section by means of positioning pins.

Preferred refinements of the invention emerge from the dependent claims and the following description. Exemplary embodiments of the invention are explained in more detail with the aid of the drawings, but are not restricted to these exemplary embodiments. The accompanying drawings show:

Description of drawings

FIG. 1 : Partial cross-section of a hydraulic bolt tensioning device according to the invention.

Table of reference signs

10 hydraulic tensioning device

11 bolts

12 parts

13 hydraulic piston

14 intermediate components

15 shell

16 shell section

17 cover

18 end

19 end

20 end

22 contraction part

22 positioning pin

23 Groove

24 positioning pin

25 pressure parts

26 nuts

Detailed ways

The invention here relates to a hydraulic tensioning device, ie a hydraulic screw tensioning device. FIG. 1 shows a tensioning device 10 according to the invention with a bolt 11 and a component 12 to be tensioned by means of the bolt.

The hydraulic tensioning device 10 includes a hydraulic piston 13 . The hydraulic piston 13 can be acted upon with a hydraulic medium in order to provide tension to the screw 11 . The tension acting on the hydraulic piston 13 can be transmitted to the screw 11 via an intermediate component 14 designed as an expansion nut.

In FIG. 1 , the hydraulic piston 13 and the intermediate component 14 designed as an expansion nut are surrounded by a housing 15 , wherein the housing 15 includes a cylindrical housing section 16 and a cover plate 17 .

The intermediate component 14 configured as an expansion nut is screwed at a first end 18 to the hydraulic piston 13 and at a second end 19 to the end 20 of the screw 11 to be tensioned. Adjacent to the first end 18 of the intermediate component 14 designed as an expansion nut, the housing 15 , that is to say the cylindrical housing section 16 , has a tapering or constriction 21 . Adjacent to the second end of the intermediate component 14 configured as an expansion nut, the housing 15 , that is to say the cylindrical housing section 16 , is assigned a positioning pin 22 which engages in a recess of the intermediate component 14 . slot 23. The cover plate 17 is fastened to the cylindrical housing section 16 via positioning pins 24 .

According to FIG. 1, a pressure member 25 is arranged between the hydraulic tensioning device 10 and the part 12 to be tensioned by means of the bolt 11. According to FIG. nut 26.

When the hydraulic tensioning device works, if the intermediate member 14 configured as an expansion nut breaks between the hydraulic piston 13 and the end 20 of the bolt 11, the contraction portion 21 of the housing 15 prevents the upper snap-off part of the intermediate member 14 from contacting the hydraulic pressure. Pistons 13 fly upward together. The housing 15 is fastened by means of dowel pins 22 to the lower snap-off part of the intermediate component 14 which remains on the bolt 21 .

Conversely, when the tensioning device is working, if the hydraulic piston 13 on the intermediate member 14 breaks, the positioning pin 24 of the cover plate 17 prevents the hydraulic piston 13 from breaking away from the housing 15 . The housing 15 is in turn fixed in its position by means of positioning pins 22 which engage in recesses 23 of the intermediate component 14 designed as expansion nuts.

Therefore, the hydraulic tensioning device according to the present invention has a breakage protection capability for the intermediate member 14 and the hydraulic piston 13, so that when both the intermediate member 14 and the hydraulic piston 13 are broken, the broken parts are prevented from flying away.

Claims (4)

1. Hydraulic tensioning device having a hydraulic piston loaded by a hydraulic medium, wherein the hydraulic piston transmits the tensioning force exerted on the hydraulic piston to the end of the bolt to be tensioned via an intermediate member, and wherein the hydraulic The piston and the intermediate member are surrounded by the housing, characterized in that the intermediate member (14) transmitting the tension force is screwed with the hydraulic piston (13) at the first end (18), and is screwed at the second end ( 19) Tighten with the bolt (11); and adjacent to the first end (18) of the intermediate member (14), the housing (15) is equipped with a contraction portion (21), and adjacent to the intermediate member (14) ) The second end (19) of the housing (15) is equipped with a positioning pin (22) embedded in the groove (23) of the intermediate member (14). 2. The tensioning device according to claim 1, characterized in that the tension-transmitting intermediate component (14) is designed as an expansion nut. 3. Tensioning device according to claim 1 or 2, characterized in that the housing (15) has a preferably cylindrical housing section surrounding the hydraulic piston (13) and the intermediate component (14) (16) and a cover plate (17), wherein the cover plate (17) is fastened to the housing section (16) via positioning pins (24). 4. Tensioning device according to one or more of claims 1 to 3, characterized in that between the housing (15) and the part (12) to be tensioned by means of the bolts (11) A pressure member (25) is positioned between them, and the pressure member surrounds a nut (16) tightened with the bolt (11).

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