DE29509906U1 - Spreading cylinder - Google Patents

Description

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Description

Spreading cylinder

The invention relates to an expansion cylinder, in particular for use in a walking mechanism, which can be introduced into a pipeline through an opening, wherein the opening in the pipe is significantly smaller than the clear width of the pipe cross-section and wherein clamping elements can be extended within the pipe for clamping on the inner wall of the pipe.

Walking devices for moving in non-accessible pipelines and for working on the inside of the pipe usually consist of a combination of spreading and lifting cylinders, in particular two spreading cylinders with a lifting cylinder in between. Tools and measuring and monitoring devices can then be attached to the head and/or end of the spreading cylinders and at any suitable points in between, which allow remote-controlled working on the inside of the pipe under video observation.

Before it can be used as intended, such a walking mechanism must first be inserted into the interior of the pipe through an opening in the pipeline, for example through a valve. Since such openings are usually much smaller than the pipe cross-section, the entire walking mechanism must be designed in such a way that it can be guided through the openings on the one hand, and can also move forwards inside the pipe while being supported by the pipe wall on the other. An extendable expansion cylinder is required specifically for the support on the pipe wall.

Spreading cylinders suitable for the latter purpose are not known from the state of the art. The object of the invention is therefore to create a spreading cylinder that can be accommodated in the smallest of spaces. In particular, such a spreading cylinder

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which can be used for a walking mechanism for movement in non-walkable pipelines.

The task is solved in an expansion cylinder of the type mentioned above by a multiple telescopic piston that can be extended pneumatically or hydraulically from a first, small diameter to a second, larger diameter.

Such a spreading cylinder can be arranged on both sides of a lifting cylinder and thus form a complete walking mechanism. Because the spreading cylinder does not have a larger diameter than the associated lifting cylinder when retracted, the entire walking mechanism can be introduced into a pipe through small openings and can carry out a continuous movement there with the spreading cylinder supported on the inner pipe wall via the lifting cylinder.

It is particularly advantageous that the telescopic piston can still be adjusted to a mean diameter that is slightly smaller than the inside diameter of the tube.

Further details and advantages of the invention emerge from the following description of an embodiment based on the drawing in conjunction with the subclaims. They show in a schematic representation

Figure 1 a walking mechanism consisting of a lifting cylinder and two spreading cylinders hinged to it on both sides in the retracted state,

Figure 2 shows a spreading cylinder in the partially extended state,

Figure 3 shows a section along the line II/II in Figure 2 and Figure 4 shows a plan view of a partial area perpendicular to Figure 2 or 3.

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In particular, Figures 2 to 4 are described together.

Figure 1 shows a walking mechanism which consists of the coupling of two identical spreading cylinders 200 with a lifting cylinder 100. By arranging the spreading cylinder, lifting cylinder and spreading cylinder in a known manner, a forward movement in the manner of a so-called pipe pig is possible. Since the structural units 100 and 200 are connected via joints 105 and 205 respectively, the direction of movement can vary almost as desired, so that the walking mechanism can be used within narrow and curved pipelines. Tools such as pipe internal processing equipment and measuring and monitoring equipment, such as a video camera in particular, can be attached to the head of the first spreading cylinder or the end of the second spreading cylinder - but also at any suitable location in between.

When retracted, the spreading cylinder 200 and the two lifting cylinders 100 each have a substantially egg-like shape with a round cross-section. The largest diameter of the latter determines the width of the pipe opening, which is necessary to insert the spreading cylinder and the entire moving mechanism into a pipeline (not shown). After moving inside the pipe under video observation, the processing tools can be used at the desired location.

In Figures 2 and 3, the base body of the expansion cylinder is shown with 1, on which identical clamping parts 10 and 10' are seated on opposite sides. The clamping parts 10 and 10' can be extended by means of telescopic pistons 20 and 20' in order to be clamped to the inner wall of the pipe. Springs 6 and 6 ¹ and/or the application of hydraulic or pneumatic pressure to the telescopic pistons 20 and 20' can be used to clamp the clamping parts 10 and 10'.

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Pressure medium the clamping parts 10 or 10' can be returned to their original state.

The telescopic pistons 20 and 20' are advantageously designed as multiple telescopic pistons and - like the lifting cylinder - can be operated either pneumatically or hydraulically, so that the spreading cylinder can be extended from a first, small diameter D1 to a second, larger diameter D2 for clamping. The second diameter D2 in particular corresponds to the clamping state according to the clear width of the pipe cross-section to be passed through.

During the stepping in the longitudinal direction of the pipe, the expansion cylinder 200 with the clamping parts 10 or 10' advantageously does not return to the diameter D1, since the entire stepping mechanism would then be exposed to the risk of tipping or folding. Instead, a third, middle diameter D3 can be set as the so-called stepping diameter, which is only slightly smaller than the inside pipe width. As the movement progresses, the clamping diameter D2 and the stepping diameter D3 are varied alternately in accordance with the actuation of the lifting cylinder 100.

In order to prevent an undesired, complete retraction to the small diameter Dl, a locking pawlJ|5 is provided, which automatically engages after the first full extension to the clamping diameter. As a result, during the forward movement of the step value, the working range of the telescopic pistons 20 or 20' is only between the large clamping diameter D2 and the medium step diameter D3.

In particular, it is clear from the partial sections of Figures 2 and 4 that the outer lifting cylinder 20 or 20' is mounted in conical springs 26, which absorb the entire stroke. The inner lifting cylinder 25 can be mounted in the conical spring

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fully retracted. This ensures an optimal stroke of the clamping parts with a compact design.

The function of the locking pawl 15, with which the stroke of the clamping parts 10 or 10' can be limited to the average diameter D3, is particularly evident from the partial sections in Figures 3 and 4. As soon as the clamping parts 10 or 10' are extended, the pawl 35 is inclined against spring pressure and thus limits the complete retraction of the lifting cylinder 20 or 20'. The locking pawl 35 can be reset to its original state using an auxiliary cylinder 30.

The locking pawl 35 is released via the auxiliary cylinder 30 so that the two expansion cylinders can be returned to the first, small diameter Dl after use. At the same time, the pneumatic or hydraulic line is released for the complete return stroke by a drilling system in the auxiliary cylinder 30. When the expansion cylinders are retracted, the walking mechanism can be removed from the inside of the pipe again.

Claims (7)

Protection claims 1. Spreading cylinder, in particular for use in a walking mechanism, which can be introduced into a pipeline through an opening, wherein the opening in the pipe is significantly smaller than the clear width of the pipe cross-section and wherein clamping elements can be extended inside the pipe for clamping on the inner wall of the pipe, characterized by at least one telescopic piston (20, 20') which can be extended pneumatically or hydraulically from a first, small diameter (Dl) to a second, larger diameter (D2) for actuating the clamping elements (10, 10'). 2. Spreading cylinder according to claim 1 or claim 2, d a - characterized in that the telescopic piston (20, 20') is further adjustable to a mean diameter (D3) which is slightly smaller than the clear width of the pipe cross-section. 3. Spreading cylinder according to claim 1, characterized in that a locking pawl (15) is provided which automatically engages after the telescopic piston (20, 20') has been fully extended and prevents it from shrinking to the small diameter (Dl). 25 4. Spreading cylinder according to claim 3, characterized in that an auxiliary cylinder (30) is present, with which the locking pawl (15) is released and at the same time pneumatic-hydraulic lines are released for a return stroke. 5. Spreading cylinder according to claim 1, characterized in that the telescopic piston is a multiple telescopic piston (20, 25). 35 95 S 3 h 3 8 6. Spreading cylinder according to claim 5, characterized in that the multiple telescopic piston consists of an outer piston (20) and an inner piston (25), whereby the inner piston (25) can be retracted into the outer piston (20). 7. Spreading cylinder according to claim 6, characterized in that a conical spring (26) is introduced into the outer piston (20).