EP1598481B1 - Pile driving cap - Google Patents

Abstract

A pile driver raises a hammer weight to a height which is then driven down to impinge on a circular driver block resting on top of a pile. The driver block lower face has a series of radial grooves (11) extending from the centre of the driver block to the outer margin.

Description

The invention relates to a striking medium for a pile driver, in which a striking body is raised and then accelerated down until it hits the impact medium, which sits on a pile, the impact energy of the impactor is passed over the impact medium in the pile to this in to stamp the ground.

In particular, in connection with hydraulic pile drivers, in which the impactor is designed as a case body, occurs during foundation work under water, the problem that the hollow pile is filled with water and with progressive penetration of the pile into the ground the water must escape from the pile. Since the impact medium is on the pile, the water can not easily escape from the upper pile opening. It has therefore already tried to introduce holes in the impact medium, through which the water can escape. However, this has the disadvantage that this reduces the impact resistance of the impact medium and during continuous operation under harsh conditions, the impact medium is destroyed under the blows of the impactor. Such a solution will be in JP-61 021 227 A described. An alternative is to place holes in the pile through which the water can escape. However, for reasons of strength and life of the pile, one would like to avoid such holes in the pile.

The object of the invention is to provide a striking medium, which has a long service life and can be rammed with the piles under water, without the piles must have holes.

The solution according to the invention is that the impact medium is provided at its intended for resting on the pile bottom with grooves that extend over an area extending from the interior of the hollow pile extends over its wall to beyond its outer area. The water located in the interior of the pile can thus flow outward through the grooves according to the invention, whereby, according to the course of the grooves, it makes its way from the interior of the pile to the outside via its wall. In the arrangement according to the invention, neither holes in the pile nor in the impact medium are required. It has surprisingly been found that the grooves according to the invention do not affect the stability of the impact medium. The impact medium according to the invention thus achieves lifetimes of conventional impact media without holes. So far, the experts had assumed that any grooves, heels and notches would immediately lead to the destruction of the impact medium in hard continuous use. The invention deserves the merit of having overcome this prejudice of the professional world.

In a simple embodiment of the invention, it is recommended that the grooves extend in the radial direction. In this way, the water reaches the quickest and most direct way from the inside to the outside. However, the invention also extends to embodiments in which the grooves run obliquely or bent, for example helically.

Also, because of the ease of manufacture and good efficiency with respect to the removal of the excess water from the interior of the hollow pile, it is recommended that the grooves extend to the radially outer edge of the impact medium. However, the invention also includes embodiments in which the grooves terminate even before the outer edge of the impact medium, but outside the outer edge of the pile to be driven, because even such configured grooves are able to direct the water from the inside out.

In an embodiment of the invention, it is recommended that the width of the grooves is designed to be increasingly radially outward. This measure is for the same reason as another recommended embodiment, according to which the depth of the grooves is increasingly designed radially outwardly. Both measures individually or in combination cause an enlargement of the cross section of the grooves from the inside to the outside, whereby the water to be discharged particularly effectively reaches the outside, because of each groove to be drained space share also increases radially from the inside out.

In a particularly preferred embodiment, the depth of the grooves radially inwardly designed such decreasing that the grooves smoothly pass over from a certain distance from the center of the impact medium in the lower surface of the impact medium and disappear. By this measure, one obtains a particularly smooth sliding transition, whereby the strength of the impact medium is practically not reduced compared to an embodiment without grooves.

For the same reason, it is proposed in a further embodiment of the invention that the groove edges and the groove base are configured rounded, so that the groove profile has a waveform. The inventively designed grooves thus have no sharp edges that could be the occasion or starting point for the formation of cracks in the impact medium.

In development of the invention it is provided that the impact medium is designed as a striking plate, which cooperates with an anvil part. By this configuration, the production is simplified and allows for less costly replacement of individual small parts instead of a large wear.

Correct interaction and contact between the impact plate and the anvil part, in particular a defined contact surface is ensured by the measure that the impact plate has a recess on its upper side and the anvil member rests on a raised edge around the recess.

If the impact medium has 12 grooves which are arranged at substantially equal angular intervals to each other, one obtains a particularly uniform and strong resilient component, which is also relatively inexpensive to produce.

Figur 1:

eine teilweise geschnittene Draufsicht auf eine hydraulische Pfahlramme;

Figur 2:

eine Draufsicht auf die Oberseite einer erfindungsgemäßen Schlagplatte;

Figur 3:

eine Draufsicht auf die Unterseite einer erfindungsgemäßen Schlagplatte;

Figur 4:

eine teilweise gemäß Linie A - A von Figur 2 geschnittene Seitenansicht derselben Schlagplatte;

Figur 5:

ein Detail Z aus Figur 4 in vergrößerter Darstellung;

Figur 6:

ein Detail Y aus Figur 4 in vergrößerter Darstellung;

Figur 7:

eine Teilansicht einer erfindungsgemäßen Nut in vergrößerter Darstellung;

Figur 8:

ein Detail X aus Figur 4 in vergrößerter Darstellung.

An embodiment of the invention will be explained in more detail with reference to the drawings. The figures show in detail:

FIG. 1:

a partially sectioned plan view of a hydraulic pile driver;

FIG. 2:

a plan view of the top of a striking plate according to the invention;

FIG. 3:

a plan view of the underside of a striking plate according to the invention;

FIG. 4:

a part according to line A - A of FIG. 2 cut side view of the same striking plate;

FIG. 5:

a detail Z out FIG. 4 in an enlarged view;

FIG. 6:

a detail Y out FIG. 4 in an enlarged view;

FIG. 7:

a partial view of a groove according to the invention in an enlarged view;

FIG. 8:

a detail X out FIG. 4 in an enlarged view.

In FIG. 1 can be seen a pile driver 1 with a hydraulic drive 2, with a case body 3 can be raised and then accelerated down until it meets an anvil 4, which lies on a striking plate 5. The anvil 4 and the impact plate 5 together form a striking medium, which serves to initiate the impact energy imparted by the striking body 3 into a pile 6 to be driven into the ground. The hollow pile 6 has the shape of a tube and consists practically only of the pile wall 7. The striking plate 5 rests on an upper edge 8 of the pile 6. A guide portion 9 of the pile driver 1 is inserted over the upper end of the pile 6 and holds the pile driver 1 in relation to the pile 6 in the correct vertical position.

How to best in FIG. 3 recognizes the impact plate 5 of the impact medium 4, 5 is provided at its intended to rest on the upper edge 8 of the pile 6 bottom 10 with grooves 11, each having a radially inner end 12 and radially outer end 13. From their inner end 12 to their outer end 13, the grooves 11 extend over a region which is in the ready state of the impact plate 5 in the pile driver 1 above the upper edge 8 of the pile 6 and from the inner region 14 of the hollow pile 6 on the pile wall 7 extends into the outer area 15 ( FIG. 1 ). As a result, the water in the pile 6 during the execution of a shock by the impactor 3 in the direction of arrow 16 of FIG. 3 drain radially outward.

In order to allow a uniform flow of water over the entire surface of the bottom 10 of the impact plate 5, a total of 12 radially aligned grooves 11 are arranged at equal angular intervals 17 to each other in a circle. All grooves 11 extend to the radial outer edge 18 of the striking plate 5, in which the respective outer ends 13 of the grooves 11 are located.

How to best in FIG. 7 detects, takes the width 19, 20, 21 in the direction of arrow 16 from the radially inner end 12 to the radially outer end 13 toward.

How to best in FIG. 5 detects, also increases the depth 22, 23, 24 of the grooves 11 in the direction of arrow 16 radially outward. Less well recognizable is the configuration of the grooves 11 toward its radially inner end 12, where the depth 22 of the grooves 11 decreases such that the grooves 11 from a certain distance 25 from the center 26 of the impact plate 5 in the lower surface 10 of the impact plate 5 gently pass over and disappear at this point 12.

How to best in FIG. 6 detects, the upper groove edges 27 and the groove bottom 28 are provided with curves, so that the groove profile has a waveform.

How to best in the FIGS. 2 and 8 recognizes the impact plate 5 is provided on its upper side 29 with a recess 30. A raised edge 31 arranged around the recess 30 serves to support the anvil part 4, wherein a contact surface for the anvil part 4 is fixed on the striking plate 5 and a lever arm for the acting forces is minimized.

LIST OF REFERENCE NUMBERS

1

Piledriver

2

drive

3

Falling body, striking body

4

Anvil, anvil part

5

impact plate

6

stake

7

pile wall

8th

top edge

9

guide section

10

bottom

11

groove

12

inner end

13

outer end

14

interior

15

outdoors

16

arrow

17

angular distance

18

Outer edge

19

width

20

width

21

width

22

depth

23

depth

24

depth

25

distance

26

Focus

27

groove edges

28

groove base

29

top

30

deepening

31

edge

Claims (10)

1. Hammering medium for a piledriver (1) in which a hammering body (3) is raised and then accelerated downwards until it strikes the hammering medium (4, 5) which is seated on a pile (6), wherein the impact energy of the hammering body (3) is channelled via the hammering medium (4, 5) into the pile (6) in order to ram it into the ground, characterized in that the hammering medium (4, 5) is provided on its lower side (10), which is intended to lie on top of the pile (6), with grooves (11) which run over a region which extends from the inner region (14) of the hollow pile (6) and over its pile wall (7) into its outer region (15).
2. Hammering medium according to Claim 1, characterized in that the grooves (11) extend in radial directions (16).
3. Hammering medium according to Claim 1 or 2, characterized in that the grooves (11) extend as far as the radially outer edge (18) of the hammering medium (5).
4. Hammering medium according to one of the preceding claims, characterized in that the width (19, 20, 21) of the grooves (11) is designed to increase radially outwards.
5. Hammering medium according to one of the preceding claims, characterized in that the depth (22, 23, 24) of the grooves (11) is designed to increase radially outwardly.
6. Hammering medium according to one of the preceding claims, characterized in that the depth (22, 23, 24) of the grooves (11) is designed to decrease radially inwardly in such a way that the grooves (11) merge smoothly into the lower face (10) of the hammering medium (5) and disappear at a certain distance (25) from the midpoint (26) of the hammering medium (5).
7. Hammering medium according to one of the preceding claims, characterized in that the groove edges (27) and the groove base (28) are designed to be rounded off such that the groove profile has a wavy shape.
8. Hammering medium according to one of the preceding claims, characterized in that it is designed as a hammering plate (5) which cooperates with an anvil part (4).
9. Hammering medium according to Claim 8, characterized in that the hammering plate (5) has a depression (30) on its upper side (29) and the anvil part (4) lies on a raised edge (31) around the depression (30).
10. Hammering medium according to one of the preceding claims, characterized in that twelve grooves (11) are provided which are substantially arranged with uniform angular spacings (17) from one another.

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