CN2229345Y - Mechanical expander for thermal shrinking tube - Google Patents

Abstract

The utility model relates to a mechanical expander for a thermal shrinking tube. A plurality of web members are fixed on a guide sleeve, and the web member is penetrated in the middle of an expanded tube blank. An expansion body is arranged on one end of the guide sleeve, and a guide slot is opened on the outer surface of the expansion body. A platform or a groove is milled on the peripheral surface between two guide grooves. The web member is expanded in radial direction in company with the propulsion of the expansion body along axial direction, as a result, the tube blank sheathed on the web member is gradually expanded along radial direction to form a polygon tube. The utility model has the advantages that the number of the web member is used by the device is not severely restricted, the tube expanding is flexible, the tube expanding is convenient, the shape of the manufactured product is regular, and the axial tensile deformation can not be generated.

Description

Heat-shrinkable tube mechanical expanding device

The utility model relates to a kind of mechanical expanding device of producing heat-shrinkable tube.

Heat-shrinkable tube is the high molecular products with " elastic memory " that adopts macromolecular material to make.Its production method comprises: air pressure inflation method and mechanical expansion method.The air pressure inflation method is to expand by compressed air to uphold the method for finishing, and generally is applicable to the pipe expansion that draw ratio is less.The mechanical expansion method is the method for pipe being expanded by the mechanical movement of regulation.Be applicable to small-bore, elongated pipe.No matter which kind of method generally all requires the expand tube device can guarantee that in the expand tube process flexible pipe base does not produce the axial tension distortion, so that heat-shrinkable tube only radially shrinks in use.The Chinese patent (application number 9424765.9) of the applicant's application is produced the improvement that the heat-shrinkable tube device carries out for above-mentioned purpose to inflation method exactly.And at present when producing small-bore, elongated heat collapsible tube, what often adopt is the mechanical expanding device.This device generally is made up of a supporter and dilator bar, be enclosed within on the supporter by the expander base, after being heated to uniform temperature, dilator bar along supporter one end from being entered by an end of expander, to other end motion, finish wholely by after the expansion of expander, again pipe is cooled off, withdraw from dilator bar, make goods.Because dilator bar is direct side face contact during pipe in expansion, thus pipe radially expanded open in, also with the axially-movable generation axial tension of dilator bar, and produce " axial deformation memory effect ".

1994 the 8th the 3rd phases of volume of " Chinese plastics " magazine have been introduced " web member cone method " and have reached " web member cylinder method ".The mechanical expansion device that this method is used has solved the problem of axial tension preferably.

This device has one group of elongated web member (steel wire) to be fixed on the fairlead equably, be enclosed within outside the web member group by the expander base, fairlead one end has an expansion body (circular cone or cylinder), during expander, expansion body is inserted in the web member group from fairlead and is axially moved, the web member group is opened gradually by expansion, and the pipe that is enclosed within on the web member group is radially expanded simultaneously.This moment, pipe did not directly contact with the expansion body surface of motion vertically, had avoided producing axial tension thereupon.In addition, expand the pipe inner peripheral surface of opening and only contact, reduced the CONTACT WITH FRICTION area with every web member generation line.This device adopts many web member expansions to support, so in fact the heat-shrinkable tube of producing becomes polygonal.

Cross sectional shape schematic diagram when Fig. 3 is expander.

On goods, stay obvious marks, need to adopt many web members 4 as far as possible, make goods be similar to circle.When but pipe midfield pole-footing number is too much, limit by pipe 2 internal diameter sizes, wear to pass by.And the web member radical after a little while, tangent line line distance is long between the contact point of pipe and each web member contact position cross section, cause this line middle part to be equal to or less than the radius R of expansion body apart from the distance h at expansion body 5 centers, the pipe at middle part between two web members is directly contacted with the expansion body surface, produce axial tension or expanded obvious projection, on goods, stay irregular corner angle vestige (see figure 3) on the contrary.So during with this mechanical expansion device expander, calculate the radical of the web member of use,, use underaction, convenience to avoid adding the irregular deformation in man-hour earlier through strict calculating.

The purpose of this utility model: provide a kind of use web member radical not to be subjected to strict restriction, and can guarantee the mechanical expanding device of expander shape standard.

Major technique measure of the present utility model: this device comprises a fairlead, is fixed with one group of web member on it, and an expansion body (awl or cylinder) is arranged in the fairlead.Evenly have the web member gathering sill at the expansion body outer surface, the middle part, expansion body surface between the two adjacent gathering sills also is split into the groove shape or is milled with platform.When expansion body enters fairlead from fairlead one end, expand when opening the web member group, each web member is radially opened gradually along the gathering sill of expansion body outer surface, is enclosed within the outer pipe of web member group is expanded into rule with radially upholding of each web member polygon pipe.At this moment, because there is recessed groove on the expansion body surface between two web members, although the web member number is less, the tangent line line is longer, and pipe also no longer directly contacts with the expansion body surface of axially-movable, or is convex by expansion.

Above-mentioned expansion body is the cylindrical rod that front end has tapering, and the web member gathering sill of opening on it is semicircle or rectangle.Expansion body surface between two gathering sills is milled into platform or is had the groove that the cross section is a rectangle.Web member adopts one group of supporting steel wire.

Effect of the present utility model: this device passes through the improvement to the shape on expansion body surface, avoided the web member radical more after a little while, goods are expanded irregular protruding phenomenon at two contact point tangent line lines middle part, therefore this device expander regular shape does not produce axial tension again, and the web member radical is not subjected to strict restriction, use flexibly, with the web member group of same radical, but the scope increase of expander footpath is easy to process.For example: the pipe of processing φ 30-φ 70 all can adopt 6 web members, and can both guarantee the expander regular shape, does not go out projection.This is difficult to guarantee for the common mechanical pipe expander.

Open in detail below in conjunction with accompanying drawing to the utility model.

Fig. 1 is a structural representation of the present utility model.

Fig. 2 is A-A profile of Fig. 1.

This mechanical expanding device has the ring flange 3 of fairlead effect together, evenly fix one group of finer wire 4 around the ring flange hole as supporting web member, steel wire penetrates by expander base 2, expansion body 5 is cylinders that front end has tapering, outer peripheral face has the steel wire gathering sill 6 of semicircle (or rectangle) equably, be milled with the groove of rectangle or other shapes on the face of cylinder between two holddown grooves, make the middle part, the face of cylinder between two gathering sills be the recess (see figure 2).Steel wire radical fixing on ring flange 3 is decided on processed pipe diameter, and the caliber of general φ 30-φ 70 can be done support with 6 steel wires.Expansion body enters from the ring flange hole, because front end is the conical surface that has the steel wire gathering sill, so steel wire is easy to embed gathering sill.After heating of pipe blank, expansion body is moved vertically, inserts in the middle of the steel wire group, steel wire keeps parallel each other along gathering sill, is radially expanded gradually and opens, and is enclosed within the outer pipe of steel wire group and is also expanded into the hexagon tubulose along radial direction, through cooling, make the heat-shrinkable tube goods.

Claims (3)

1, a kind of mechanical expanding device of producing heat-shrinkable tube, include fairlead (3), around trepanning, be fixed with one group of web member (4), one expansion body (5) is arranged in the fairlead, it is characterized in that: the expansion body outer surface has the web member gathering sill equably, and the side face between the per two adjacent gathering sills has groove or platform.

2, according to claims 1 described expand tube device, it is characterized in that: expansion body is the cylinder that a front end has tapering, and the web member gathering sill on it is rectangle or semi-circular recesses.

3, according to claim 1,2 described expand tube devices, it is characterized in that: cylinder on the expansion body between two web member gathering sills middle part has the cross section to be square groove or to be milled with circle and to lack platform.

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