CN207393134U - A kind of thread screw on and-off machine large torque floating back-up tong - Google Patents

Abstract

The utility model provides a kind of thread screw on and-off machine large torque floating back-up tong, including：Two panels are connected by fixed link, and top opens up clamping endoporus；Hydraulic cylinder leg assembly, is set up between two panels, including：Two support plates, top open up clamping through hole, and clamping through hole internal diameter is less than clamping bore inner diameter, outer surface projection circumference righting idler wheel, circumference righting idler wheel stretches into clamping endoporus, leaves gap between outer wall and clamping endoporus inner wall, gap is left between two support plate outer surfaces and two panels inner surface；A circular connector is inscribed between two support plates, it is circumferentially spaced that several supported holes are set；Several hydraulic cylinders, are inserted in supported hole respectively；Back-up tong stent is arranged on thread screw on and-off machine chassis, and two panels are set up in respectively on back-up tong stent；One support spring, upper/lower terminal are connected respectively with shape connector bottom surface and back-up tong rack upper surface.The back-up tong ensure that work efficiency and product quality and service life increases, low, easy to maintain, the easy popularization of production cost.

Description

A kind of thread screw on and-off machine large torque floating back-up tong

Technical field

The utility model belongs to oil equipment technology field, and in particular, to a kind of thread screw on and-off machine large torque floating back-up tong.

Background technology

From well known, such as threaded connection of oil pipe, casing, downhole tool, drilling rod of pipe tool is all with twisting in existing oil field workshop Deduction carries out, and work efficiency is high, safe and reliable, guarantee thread quality.

Main pincers, back-up tong of the host of a full set of thread screw on and-off machine generally by rotating（It blocks tube body not rotate, forms back strength）It is and main Pincers, the connecting base plate of back-up tong, chassis is to be bolted with main clipper joint, and axial direction of the main pincers on chassis will not move left and right, Connection between chassis and back-up tong is roller-coaster connection, and such connection mode is the helicoid upper shackle size of regulation pipe Variation.

Clamping mode generally has（1）Frontal plate slope climbing type,（2）Planet claw clip compact form,（3）Main pincers and back-up tong are all oil cylinder folders Tightly, and main pincers are 360 degree of rotations.

For thread screw on and-off machine, the current country is primarily present following patent document：

Chinese patent Authorization Notice No.：CN103527117B discloses a kind of 360 ° continuous rotation large torque thread screw on and-off machine, by Continuously rotate main pincers, back-up tong and pedestal composition；It is described continuously to rotate main pincers, back-up tong respectively by the first support plate, the second support Plate is arranged on pedestal both ends.The continuous rotation large torque thread screw on and-off machine of 360 ° of one kind of the utility model, design is reasonable, service life It is long, the scope of clamped caliber during processing work is on the one hand improved, has prevented the damage in itself to drilling tool, on the other hand 360 ° of rotation torques are big and easy to operate, improve production work efficiency, saved human cost input, thereby reduce enterprise Productive statistics and the personal safety that ensure that operating personnel；The utility model popularization easy to operate, easy to maintain, easy simultaneously.

For the thread screw on and-off machine that the patent is provided, the idler wheel below general back-up tong has upper and lower gap, purpose adjustment pipe tool It puts, the small eccentricity that the error in length that main back-up tong oil cylinder stretches out is formed, when back-up tong is light-weight, one of tube body is tight in main clamp When, other end can provoke the light back-up tong of comparison, this is very effective method.

When pipe diameter is big, torque is big, intensity must increase naturally when back-up tong designs, then weight is increased by, so-called The decentraction of main back-up tong derive from（1）The error of main pincers a few pawl strokes of clamping device；（2）Several pawls of back-ups cramping arrangement stretch The error of amount；（3）The initial position that operator puts workpiece is not right, makes what tube body was sideling put；（4）Main pincers, back-up tong mismachining tolerance, such as The high error in center, transverse dimension error etc..

When pipe diameter is big, torque is big, intensity increases naturally when back-up tong designs, then weight is increased by, and pipe tool occurs Put, main back-up tong oil cylinder stretch out error in length formed small eccentricity when, tube body can not provoke heavier back-up tong, that is to say, that Entire back-up tong is too heavy, can not float, and is at this moment present with screw thread damage, on screw thread during button or shackle, screw thread position fever.

Back-up tong is its important composition component in thread screw on and-off machine, rational design can improve the work efficiency of thread screw on and-off machine with Ensure to twist the quality of button, but the design of existing back-up tong is unreasonable, the fever of thread damage and screw thread position easily occurs for when work, Being shut down when on the one hand repairing reduces work efficiency, adds business burden, if on the other hand problem discovery will cause not in time There are quality problems in product（After the thread damage of some instruments, when oil field unit is constructed, after instrument is gone into the well, it be easy to cause Well accident, leakage accident）, reduce market competitiveness of enterprises；Its service life is short simultaneously, adds entreprise cost input.

Utility model content

It is above-mentioned to solve the problems, such as, it is floated and carried on the back with large torque the purpose of this utility model is to provide a kind of thread screw on and-off machine Pincers, back-up tong design is unreasonable when the back-up tong solves existing thread screw on and-off machine large torque, causes thread screw on and-off machine work efficiency low and product Ropy problem ensure that shackle screw thread is not destroyed, and ensure that work efficiency and product quality and service life increases, So as to reduce enterprise's production cost input, enterprise is made to remain advantage in market competition, production cost is low, maintenance side Just, easily promote.

In order to achieve the above objectives, the technical solution of the utility model is：

A kind of thread screw on and-off machine large torque floating back-up tong, the back-up tong include：Two panels, vertical spacing arrangement, and if passing through Solid fixed pole is connected to each other, and top opens up the corresponding clamping endoporus for being used to clamp pipe fitting respectively；Hydraulic cylinder leg assembly erects It is directly set up between the two panels, including：Support plate that is two vertical, being intervally arranged, two support plate tops open up phase respectively Corresponding clamping through hole, the connection corresponding with two clamping endoporus of two clamping through holes form one for clamping the holding chamber of pipe fitting, clamping Through hole internal diameter is less than the clamping bore inner diameter, and two support plate outer surfaces are located at the position edge clamping through hole week of clamping through hole periphery To interval several circumference righting idler wheels of projection, circumference righting idler wheel stretches into the clamping endoporus, and circumference righting idler wheel outer wall with Gap is left between clamping endoporus inner wall, gap is left between two support plate outer surfaces and two panels inner surface；Two support plate phases A circular connector is inscribed along clamping through hole periphery between opposite, circular connector is circumferentially spaced to set several supported holes；If Dry hydraulic cylinder is inserted in respectively in the circular connector supported hole, and piston rod is stretched into the holding chamber and formed to pipe fitting Clamping；Back-up tong stent is slideably positioned on thread screw on and-off machine chassis, and two panels are set up in respectively on the back-up tong stent；One support bullet Spring is vertically arranged, and upper/lower terminal connects respectively with the hydraulic cylinder leg assembly circular connector bottom surface and back-up tong rack upper surface It connects, forms the righting to hydraulic cylinder leg assembly, ensure back-up tong several circumference righting idler wheel axle center institutes during pipe fitting is clamped It is concentric circles in circle and clamping endoporus.

Further, the two panels top opens up several corresponding fixations close to outer fringe position is circumferentially spaced respectively Hole, the fixed link both ends be inserted in respectively two panels mounting hole formed two panels between connect, fix；The fixed link is Hexagon-headed bolt is relatively fixed between fixed link and mounting hole by positioning spacer, washer and nut.

Further, the support spring is equipped with one with hydraulic cylinder leg assembly circular connector bottom surface connecting pin outer sheath Upper spring spool, spring spool one end is connected to circular connector bottom surface on this；Support spring is connected with back-up tong rack upper surface Outer sheath is held to be equipped with, and spring spool, the lower spring spool one end are connected to back-up tong rack upper surface；Upper and lower spring spool is matched somebody with somebody The /V formed to the support spring is closed, prevents support spring stress from overturning.

Further, the circular connector includes several muscle that two support plates are inscribed in along weekly interval outside support through holes Plate, the interval between adjacent two gusset form supported hole, and the supported hole is square hole, forms clamping, the /V to hydraulic cylinder.

Further, the circular connector includes several muscle that two support plates are inscribed in along weekly interval outside support through holes Plate, supported hole are opened in gusset surface respectively, and the supported hole is square hole, forms clamping, the /V to hydraulic cylinder.

Further, two panels lower part both ends offer a connection through hole respectively, accordingly, under two support plate Portion both ends offer a connecting hole respectively, and two groups of connecting rod ASSY both ends are respectively with the connecting hole positioned at homonymy and being connected through hole and connecting It connects, the connecting rod ASSY includes：One end and first connecting rod, one end and the second connecting rod of connecting hole connection for being connected through hole connection, The adjacent one end of first, second connecting rod is formed by axis pin and is rotatably connected.

Further, two support plate is prolonged respectively including what disk and disk lower end edge disk radially extended outward to form Long portion, the connecting hole are opened in extension lower part both ends, and the clamping through hole is opened on disk.

Further, the position of the two panels respective link assembly offers mounting hole, and torque sensor passes through the peace Dress hole is installed on first connecting rod or second connecting rod.

Further, the back-up tong stent includes two spaced bottom plates, and plate upper surface both ends are respectively along bottom plate height Degree direction opens up the groove being inserted in for the two panels on back-up tong stent, and two bottom plate lower part both ends pass through nuts and washers respectively One is removably connected with for limiting the lower righting idler wheel that back-up tong moves up and down, back-up tong stent is long along chassis by lower righting idler wheel Spend direction or so rolling.

Further, righting roller mount in one side is respectively equipped in the middle part of the two bottom plate lower surface of back-up tong stent, two are used to limit The side righting idler wheel of back-up tong transverse shifting processed is removably connected to by nuts and washers in side righting roller mount respectively.

The beneficial effects of the utility model are：

Gap is left between two support plates and panel of the back-up tong hydraulic cylinder leg assembly, changes the existing thread screw on and-off machine back of the body The structure that hydraulic cylinder leg assembly pasting panel is set is clamped, assigns activity space of the hydraulic cylinder leg assembly between two panels；

For hydraulic cylinder leg assembly by being connected between support spring and back-up tong stent, such structure makes back-up tong hydraulic cylinder branch Frame assembly can rise in two panels to drop, can a left side can be right, can small angle rotation, that is to say, that back-up tong hydraulic cylinder leg assembly has clothes From the adjusting space that main clamp tightly moves towards.

When there is the decentraction situation of main back-up tong, main clamp clamp force makes tube body extend according to the guiding at the tight position of main clamp It moves towards, at this moment back-up tong clamp assembly starts to clamp tube body, and the total weight of back-up tong hydraulic cylinder leg assembly is than entire back-up tong total weight Light, such pipe fitting just provokes back-up tong hydraulic cylinder leg assembly, drives hydraulic cylinder leg assembly movable between two panels；

When upper button or shackle, back-up tong hydraulic cylinder leg assembly works in floating, this work is driven, and And submit to main pincers.That is, back-up tong hydraulic cylinder leg assembly small-scale can be swung with living main pincers migration.

Old design originally is entire back-up tong（That is the components such as hydraulic cylinder leg assembly, panel, back-up tong stent）It is small floating It is dynamic, and the design of back-up tong provided by the utility model, it is that the hydraulic cylinder leg assembly inside back-up tong is floating.

So screw thread be under loose environment on unload, will not be squeezed, will not be damaged partially, will not be generated heat.

Meanwhile several circumference righting idler wheels are set in support plate clamping through hole periphery, hydraulic cylinder leg assembly was floating Cheng Zhong clamps endoporus inner wall against limitation hydraulic cylinder leg is total by the circumference righting idler wheel and the panel that are convexly equipped in support plate It is liquid into the domain of walker in two panels, i.e. the distance between circumference righting idler wheel outer wall to panel clamping endoporus inner wall Domain of walker of the cylinder pressure bracket assembly in two panels；

Hydraulic cylinder leg assembly coordinates pullling for support spring in location free procedure, ensures the axle center of several circumference righting wheels The circle at place and the clamping endoporus of panel are concentric circles；

The design of upper and lower spring spool, forms the /V to support spring, prevents from overturning after support spring stress running away；

The lower part of connecting rod ASSY connection back-up tong hydraulic cylinder leg assembly and two panels, machined below two panels pair The hole answered can fill torque sensor test torque and use；

Lower righting idler wheel, side righting idler wheel are set, reduces the friction between back-up tong stent and thread screw on and-off machine bottom plate, extends back-up tong Service life.

Description of the drawings

Fig. 1 is a kind of structure diagram of thread screw on and-off machine large torque floating back-up tong provided by the utility model.

Fig. 2 is the side view of Fig. 1.

Specific embodiment

With reference to Fig. 1, a kind of thread screw on and-off machine described in the utility model large torque floating back-up tong, the back-up tong includes：Two sides Plate 1, vertical spacing arrangement, and is connected to each other by several fixed links 11, and top opens up corresponding for clamping pipe fitting respectively Clamping endoporus 12；Hydraulic cylinder leg assembly 2, vertical stand are arranged between the two panels 1, including：It is two vertical, be intervally arranged Support plate 21, two support plates, 21 top open up respectively it is corresponding clamping through hole 22, two clamping through holes 22 and two clamping endoporus 12, which correspond to connection, forms one for clamping the holding chamber 100 of pipe fitting, and 22 internal diameter of clamping through hole is less than clamping 12 internal diameter of endoporus, It is rolled along several circumference rightings of clamping 22 circumferentially-spaced projection of through hole the position that two support plate outer surfaces are located at 22 periphery of clamping through hole Wheel 23, circumference righting idler wheel 23 stretch into the clamping endoporus 12, and 23 outer wall of circumference righting idler wheel and clamping endoporus 12 inner wall it Between leave gap, leave gap between 1 inner surface of two support plates, 21 outer surface and two panels；Edge between two support plates, 21 opposite face A circular connector is inscribed in 22 periphery of clamping through hole（It is not shown）, circular connector is circumferentially spaced to set several supported holes（Not Diagram）；Several hydraulic cylinders 3 are inserted in respectively in the circular connector supported hole, and piston rod is stretched into the holding chamber 100 Form the clamping to pipe fitting；Back-up tong stent 4 is slideably positioned in thread screw on and-off machine chassis（It is not shown）On, two panels 1 are set up in institute respectively It states on back-up tong stent 4；One support spring 5, is vertically arranged, and upper/lower terminal is connected respectively with 2 annular of hydraulic cylinder leg assembly Part bottom surface and the connection of 4 upper surface of back-up tong stent, form the righting to hydraulic cylinder leg assembly 2, ensure back-up tong in clamping pipe fitting mistake Circle where several 23 axle center of circumference righting idler wheel and clamping endoporus 12 are concentric circles in journey.

Wherein, the circumference righting idler wheel 23 is convexly equipped in by washer, nut fixation on hydraulic cylinder leg assembly 2.

Further, 1 top of two panels close to outer fringe position respectively it is circumferentially spaced open up it is several corresponding solid Determine hole 13,11 both ends of fixed link are inserted in 1 mounting hole 13 of two panels and form connecting, fixing between two panels 1 respectively；Institute Fixed link 11 is stated as hexagon-headed bolt, passes through positioning spacer between fixed link 11 and mounting hole 13（It is not shown）, washer（Do not scheme Show）And nut 14 is relatively fixed.

Wherein, positioning spacer is between two panels 1, and is located at 11 outside of fixed link.

Further, the support spring 5 is equipped with 2 circular connector bottom surface connecting pin outer sheath of hydraulic cylinder leg assembly Spring spool 51 on one, 51 one end of spring spool is connected to circular connector bottom surface on this；In support spring 5 and back-up tong stent 4 Surface connecting pin outer sheath is equipped with once spring spool 52, lower 52 one end of spring spool are connected to 4 upper surface of back-up tong stent； Upper and lower spring spool 51,52 cooperatively forms the /V to the support spring 5, prevents 5 stress of support spring from overturning.

Further, in one preferred embodiment of the utility model, the circular connector is included along support through holes 22 Outer weekly interval is inscribed in several gussets of two support plates（It is not shown）, the interval between adjacent two gusset forms supported hole, described Supported hole is square hole, forms the clamping to hydraulic cylinder 3, /V.

Further, in another preferred embodiment of the utility model, the circular connector is included along support through holes 22 Outer weekly interval is inscribed in several gussets of two support plates, and supported hole is opened in gusset surface respectively, and the supported hole is square hole, shape Clamping, the /V of paired hydraulic cylinder.

Further, the 1 lower part both ends of two panels offer a connection through hole 15 respectively, accordingly, two support 21 lower part both ends of plate offer a connecting hole 24 respectively, two groups of 6 both ends of connecting rod ASSY respectively with the connecting hole 24 positioned at homonymy and Connection through hole 15 connects, and the connecting rod ASSY 6 includes：One end and first connecting rod 61, one end and the connection for being connected the connection of through hole 15 The second connecting rod 62 that hole 24 connects, first, second connecting rod 61,62 adjacent one end are formed by axis pin 63 and are rotatably connected.

Further, two support plate 21 includes disk 211 respectively and 211 lower end edge disk of disk extends radially outwardly The extension 212 of formation, the connecting hole 24 are opened in 212 lower part both ends of extension, and the clamping through hole 22 is opened in disk On 211.

Further, the position of the 1 respective link assembly 6 of two panels offers mounting hole 16, torque sensor（Do not scheme Show）It is installed in by the mounting hole 16 on first connecting rod 61 or second connecting rod 62.

Further, the back-up tong stent 4 includes two spaced bottom plates 41, and 41 upper surface both ends of bottom plate are respectively the bottom of along 41 short transverse of plate opens up the groove 42 being inserted in for the two panels 1 on back-up tong stent 4, and two bottom plates, 41 lower part both ends lead to respectively It crosses nuts and washers and is removably connected with one for limiting the lower righting idler wheel 7 that back-up tong moves up and down, back-up tong stent 4 is helped under Positive idler wheel 7 is along chassis length direction or so rolling.

Further, one side righting roller mount 43 is respectively equipped in the middle part of described 4 liang of 41 lower surfaces of bottom plate of back-up tong stent, it is dual-purpose Side righting roller mount 43 is removably connected to by nuts and washers respectively in the side righting idler wheel 8 of limitation back-up tong transverse shifting On.

Wherein, side righting idler wheel 8 plays back-up tong cross spacing, and back-up tong or so can roll.

Side righting roller mount 43 connects back-up tong stent 4 by hexagon-headed bolt, washer.

6 connection liquid cylinder pressure bracket assembly of connecting rod ASSY, 2 lower part and two panels 1 machined correspondence below two panels 1 Hole, can fill torque sensor test torque use.

Hydraulic cylinder 3 is fixed on by washer, nut on hydraulic cylinder leg assembly 2.

Thread screw on and-off machine provided by the utility model is as follows with large torque floating back-up tong operation principle：

Oil pipe, casing, downhole tool, the male and female screw thread of drilling rod are just put on thread screw on and-off machine upper button after pre-screwing, if If needing shackle, male and female screw thread has connected in itself.After main tight one of clamp, hydraulic cylinder 3 in back-up tong clamp assembly Piston rod just stretches into holding chamber 100 and clamps tube body.

（1）Hydraulic cylinder leg assembly 2 has 5 righting of support spring below；

（2）Two panels 1 have space moving position between hydraulic cylinder leg assembly 2；

（3）There is clearance space between 23 outer wall of circumference righting idler wheel and the clamping endoporus inner wall of panel 1；

Such structure, which makes hydraulic cylinder leg assembly 2 that can rise, to drop, can a left side can be right, can small angle rotation, that is to say, that liquid Cylinder pressure bracket assembly 2, which has, obeys the adjusting space that main clamp tightly moves towards.

When there is the decentraction situation of main back-up tong, main clamp clamp force makes tube body extend according to the guiding at the tight position of main clamp It moves towards, at this moment back-up tong clamp assembly starts to clamp tube body, and the total weight of hydraulic cylinder leg assembly 2 is lighter than entire back-up tong total weight to be obtained More, such pipe fitting just provokes hydraulic cylinder leg assembly 2；

When upper button or shackle, hydraulic cylinder leg assembly 2 works in floating, this work is driven, and Submit to main pincers.That is, hydraulic cylinder leg assembly 2 small-scale can be swung with living main pincers migration.

Old design originally is entire back-up tong moderate fluctuation, and such design, is the hydraulic cylinder leg inside back-up tong now Assembly 2 is floating.

So screw thread be under loose environment on unload, will not be squeezed, will not be damaged partially, will not be generated heat.

According to circumstances, limit spring of the left and right directions to back-up tong clamp assembly can be increased.

It should be noted that above example is merely intended for describing the technical solutions of the present application, but not for limiting the present application.Although ginseng The utility model is described in detail according to preferred embodiment, it will be understood by those of ordinary skill in the art that, it can be to reality It is modified or replaced equivalently with new technical solution, it, should all without departing from the scope of technical solutions of the utility model Cover in the right of the utility model.

Claims (10)

1. a kind of thread screw on and-off machine large torque floating back-up tong, which is characterized in that the back-up tong includes：

Two panels, vertical spacing arrangement, and are connected to each other by several fixed links, and top opens up corresponding for clamping respectively The clamping endoporus of pipe fitting；

Hydraulic cylinder leg assembly, vertical stand are arranged between the two panels, including：

Support plate that is two vertical, being intervally arranged, two support plate tops open up corresponding clamping through hole respectively, two clamping through holes with Two clamping endoporus correspond to connection and form one for clamping the holding chamber of pipe fitting, and clamping through hole internal diameter is less than in the clamping endoporus Footpath, the position that two support plate outer surfaces are located at clamping through hole periphery are rolled along several circumference rightings of the clamping circumferentially-spaced projection of through hole Wheel, circumference righting idler wheel stretches into the clamping endoporus, and leaves gap between circumference righting idler wheel outer wall and clamping endoporus inner wall, Gap is left between two support plate outer surfaces and two panels inner surface；

A circular connector, the circumferentially spaced setting of circular connector is inscribed along clamping through hole periphery between two support plate opposite faces Several supported holes；

Several hydraulic cylinders are inserted in respectively in the circular connector supported hole, and piston rod stretches into formation pair in the holding chamber The clamping of pipe fitting；

Back-up tong stent is slideably positioned on thread screw on and-off machine chassis, and two panels are set up in respectively on the back-up tong stent；

One support spring, is vertically arranged, upper/lower terminal respectively with the hydraulic cylinder leg assembly circular connector bottom surface and back-up tong Rack upper surface connects, and forms the righting to hydraulic cylinder leg assembly, ensures that back-up tong several circumference during pipe fitting is clamped are helped Circle where positive idler wheel axle center and clamping endoporus are concentric circles.

2. thread screw on and-off machine according to claim 1 large torque floating back-up tong, which is characterized in that the two panels top is close Outer fringe position is circumferentially spaced respectively to open up several corresponding mounting holes, and the fixed link both ends are inserted in two panels and consolidate respectively Determine hole formed two panels between connect, fix；The fixed link is hexagon-headed bolt, by fixed between fixed link and mounting hole Position spacer, washer and nut are relatively fixed.

3. thread screw on and-off machine according to claim 1 large torque floating back-up tong, which is characterized in that the support spring and hydraulic pressure Jar support assembly circular connector bottom surface connecting pin outer sheath is equipped with spring spool on one, and spring spool one end is connected to ring on this Shape connector bottom surface；Support spring is equipped with spring spool, the lower spring pocket with back-up tong rack upper surface connecting pin outer sheath Cylinder one end is connected to back-up tong rack upper surface；Upper and lower spring spool cooperatively forms the /V to the support spring, prevents from supporting Spring stress is overturn.

4. the thread screw on and-off machine large torque floating back-up tong according to claim 1 or 3, which is characterized in that the circular connector Several gussets including being inscribed in two support plates along weekly interval outside support through holes, the interval between adjacent two gusset form support Hole, the supported hole are square hole, form clamping, the /V to hydraulic cylinder.

5. the thread screw on and-off machine large torque floating back-up tong according to claim 1 or 3, which is characterized in that the circular connector Several gussets including being inscribed in two support plates along weekly interval outside support through holes, supported hole is opened in gusset surface respectively, described Supported hole is square hole, forms clamping, /V to hydraulic cylinder.

6. thread screw on and-off machine according to claim 1 large torque floating back-up tong, which is characterized in that two panels lower part both ends A connection through hole is offered respectively, and accordingly, the two support plates lower part both ends offer a connecting hole respectively, and two groups of connecting rods are total Into both ends respectively with the connecting hole positioned at homonymy and being connected through hole connection, the connecting rod ASSY includes：One end connects with being connected through hole The second connecting rod of the first connecting rod, one end and the connecting hole connection that connect, the adjacent one end of first, second connecting rod is formed by axis pin to rotate Connection.

7. the thread screw on and-off machine large torque floating back-up tong according to claim 1 or 6, which is characterized in that two support plate point Not Bao Kuo the extension that radially extends outward to form of disk and disk lower end edge disk, the connecting hole is opened in extension lower part Both ends, the clamping through hole are opened on disk.

8. thread screw on and-off machine according to claim 6 large torque floating back-up tong, which is characterized in that the two panels respective link The position of assembly offers mounting hole, and torque sensor is installed in by the mounting hole on first connecting rod or second connecting rod.

9. thread screw on and-off machine according to claim 1 large torque floating back-up tong, which is characterized in that the back-up tong stent includes two Spaced bottom plate, plate upper surface both ends open up along bottom plate heights direction be inserted in back-up tong stent for the two panels respectively On groove, two bottom plate lower part both ends are removably connected with one for limiting what back-up tong moved up and down by nuts and washers respectively Lower righting idler wheel, back-up tong stent is by lower righting idler wheel along chassis length direction or so rolling.

10. thread screw on and-off machine according to claim 9 large torque floating back-up tong, which is characterized in that two bottom of back-up tong stent Righting roller mount in one side is respectively equipped in the middle part of plate lower surface, two pass through respectively for limiting the side righting idler wheel of back-up tong transverse shifting Nuts and washers is removably connected in side righting roller mount.