JPS59118917A - Movable beam for preventing buckling in mandrel driver - Google Patents

Abstract

PURPOSE:To prevent the buckling of a mandrel by a method in which a slender mandrel is driven into the ground by applying a penetrating force, and as the driving process proceeds, a movable beam is moved while holding the mandrel. CONSTITUTION:A mandrel 4 whose upper end is attached with a pressing beam 5 is thrust into a hole 8a provided in a movable beam 8 for preventing buckling and while holding the intervals of plural mandrels 4, the movable beam 8 is vertically moved between guide struts 2 by a guide roller 8a. When a lifting wire 6 is loosened under the condition that a drain material is set to the mandrels 4, the mandrels 4 go down under their own weights. When the pressing wire 7 is tensed by a winch, the mandrels 4 are penetrated by the pressing beam 5 into the ground. Although the buckling load greatly acts on the intermediate portion of the mandrels 4, the buckling in the intermediate portion can always be prevented by the movable beam 8 lowering according to the driving process.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a moving beam for preventing buckling in a mandrel driving device.

In general, mandrels are made as thin as possible in order to reduce driving resistance and not disturb the ground, and the slenderness ratio is extremely high, so not only is there a risk of buckling easily, but also as the driving process of the mandrel progresses. The reality is that the part that is prone to buckling moves.

The present invention has been made in view of the above-mentioned circumstances, and has the following objects: 1- The purpose of the present invention is to move the mandrel to an optimal position and hold it at all times according to the progress of the driving stroke of the mandrel. An object of the present invention is to provide a moving beam for preventing buckling, which effectively prevents buckling.

An embodiment of the present invention will be described below with reference to the drawings.

In the figure, 1 is the main body of the driving device, and 2
A book guide post 2 is erected. the guide column 2,
The upper end portions of the booms 2 and 2 are integrally connected by a top boom 3, and the entire structure is formed into a gate shape.

4 is a mandrel, the upper end of which is attached to the push beam 5. The push-in beam 5 has a lifting wire 6
The mandrel 4 is suspended by a mandrel 4 and pulled down by a pushing wire 7 to drive the mandrel 4 into the ground.

Reference numeral 8 denotes a movable beam for buckling prevention, and the mandrels 4 pass through an insertion hole 8a formed in this, and the mandrels 4 can be moved to any position between 2 and guide columns 2 while maintaining the spacing between the plurality of mandrels 4. It can be removed by moving up and down.

Guide rollers 5a and 8b are attached to both ends of the push-in beam 5 and the movable beam 8 for preventing buckling, respectively, and roll into contact with the inner surface of the guide column 2, causing each beam 5.8 to move up and down lightly. I try to take it. 9 is a drain drum.

Next, a description will be given of a mandrel driving operation using the apparatus of the above embodiment.

First, a drain material is set on the mandrel 4 with the mandrel 4 being lifted up by the lifting wire 6 as shown in the figure. Next, when the lifting wire 6 is loosened, the mandrel 4 descends under its own weight, and its lower tip pierces the ground surface. Subsequently, when the push wire 7 is pulled by an appropriate winch (not shown), the push beam 5 is pulled downward and the mandrel 4 is pushed into the ground against the driving resistance.

When the mandrel 4 is pushed into the ground and the pushing force increases, a buckling load acts on the mandrel 4.

In this embodiment, the upper end of the mandrel 4 is fixed to the push-in beam 5, and the lower part is inserted into the ground, so the part where buckling is likely to occur is located approximately in the middle of these two parts. The position where buckling is likely to occur moves as the driving stroke of the mandrel 4 progresses and the push beam 5 descends. Therefore, the buckling prevention moving beam 8 is placed at this position.
If the mandrel 4 is moved by an appropriate control means so that it is always positioned, the mandrel 4 can be driven in a stable state without the risk of buckling.

When the driving of the mandrel 4 is completed, the pushing beam 5 is raised by 1" by the lifting wire 6, and the mandrel 4 is pulled out. At the same time, the movable beam 8 for preventing buckling is also pulled to the initial intermediate position.

Although the embodiment 1 has been described with respect to mandrel driving on land, the present invention is not limited to this and can also be used at sea, and the number of mandrels and driving means can be changed. good.

As described above, the buckling prevention movable beam of the present invention is designed to be moved to the optimum position and removed according to the driving progress of the mandrel, so that the weakest part of the mandrel is constantly reinforced. This has the advantage that not only buckling is effectively prevented, but also the driving work can be carried out smoothly without interfering with the lowering of the pusher beam.

[Brief explanation of the drawing]

The figure is a front view showing one embodiment of the present invention. 1... Driving device main body, 2, 2... Guide column, 3.
... Top boom, 4... Mandrel, 5... Pushing beam, 5a... Guide roller, 6... Lifting wire, 7... Pushing wire, 8... Moving beam for buckling prevention , 8a...Insertion hole, 8b...Guide roller, 9...Drain drum. Patent applicant: Tokyu Construction Co., Ltd. 5- Procedural amendment (voluntary) 1981 IJ]? O-guchi 1, Indication of the case 1982 Patent Application No. 21', J 4
66 No. 2, Name of the invention Moving beam 3 for buckling ribs 11 in a mandrel driving device, Person making the amendment Relationship to the case Patent application Human body Place: Shibuya, Shibuya-ku, Tokyo--R. No. 16-14 Name Tokyu Construction Co., Ltd. 4, Agent address 2-1 Yaesu, Chuo-ku, Tokyo]-2 Jobebashi Building 5, Date of amendment order 6. Column ``Detailed description of the invention-1'' of the specification to be amended. Contents of the amendment (Japanese Patent Application No. 57-219466) 1) In the 4th line from the 3rd bottom of the specification, after ``push into...'', ``Please note that the chain or It is also possible to use a pushing drive means such as hydraulic pressure." is inserted. 2) In the 5th line from the bottom of the 4th line, ``,further'' is [ru]. In this case, the guide column 2 shown in -1- may be suspended below the sea surface so that the beam 8 can be moved to the sea. Furthermore, instead of the guide column 2, the beam 8 may be guided by, for example, a leader of a pile driver. Furthermore, in the present invention, a plurality of beams 8 may be arranged and moved. Furthermore, it has been amended to ``. (Above) Patent applicant: Tokyu Construction Co., Ltd.

Claims (1)

[Claims] A mandrel driving device for driving a slender mandrel into the ground by exerting a pushing force on the mandrel, which is characterized by holding and moving the mandrel as the driving stroke of the mandrel progresses. moving beam.