CN212958433U - Portable geological exploration drilling machine suitable for high mountain and high altitude areas - Google Patents

Abstract

The utility model relates to a drilling equipment technical field specifically is a light rig of geological exploration suitable for high mountain, high altitude area. The drilling machine adopts the gasoline engine as the power supply to adopt the spiral drilling mode to carry out probing work, it mainly includes base, drilling rod, drill bit, elevating gear and drive arrangement, elevating gear sets up the upper end of base, and with the connection can be dismantled to the base, drive arrangement with the elevating gear transmission is connected, elevating gear drives drive arrangement reciprocates, drive arrangement's drive end sets up down, the vertical setting of drilling rod is in drive arrangement's below, its upper end with drive arrangement's drive end can be dismantled the connection, drill bit detachable installs the lower extreme of drilling rod, drive arrangement is used for the drive the drilling rod drives the drill bit rotates. The degree of detachability of rig is high, and the portability is strong, and the partial shipment of being convenient for is removed to satisfy the big area of the probing degree of difficulty such as mountain, high height and creep into the demand, reduce the probing cost.

Description

Portable geological exploration drilling machine suitable for high mountain and high altitude areas

Technical Field

The utility model relates to a drilling equipment technical field specifically is a light rig of geological exploration suitable for high mountain, high altitude area.

Background

Geological exploration in high mountains and high altitude areas is always an important subject of geological investigation in western regions. Most of the areas have the characteristics of steep terrain, low temperature and low oxygen, water source deficiency and the like. The drilling construction is carried out in the geological environment, the drilling machine is required to have the characteristics of light weight, high detachability and the like, and the traditional drilling equipment has the defects of difficulty in machine tool transportation, high construction difficulty, high construction and carrying cost and the like.

The portable drilling machine is a drilling machine which is portable in movement, small in size, light in weight and capable of drilling into soil layers and common rock strata, and is suitable for geological exploration in various complex environments. At present, most of domestic common portable drilling machines adopt hydraulic driving and rotary drilling modes, the overall structure is complex, the disassembly and the transportation are difficult, and the common rotary drilling mode is not suitable for high mountains and high-altitude areas lacking water sources. The portable drilling machine adopts a vibration impact drilling mode, a single component of a common vibration impactor is large in mass and not easy to split, and the drilling machine is easy to shake integrally during operation, unstable in operation and not suitable for high mountains and high altitude areas.

SUMMERY OF THE UTILITY MODEL

In view of this, the utility model provides a light rig of geological exploration suitable for high mountain, high altitude area.

The utility model provides a portable geological exploration drilling machine suitable for high mountains and high altitude areas, which comprises a base, a drill rod, a drill bit, a lifting device and a driving device, wherein the base is in a U-shaped structure, the lifting device is horizontally arranged, the lifting device is arranged at the upper end of the base and is detachably connected with the base, the driving device is arranged above the opening end of the base, and is in transmission connection with the lifting device, the lifting device is used for driving the driving device to move up and down to be far away from or close to the base, the driving end of the driving device is arranged downwards, the drill rod is vertically arranged below the driving device, the upper end of the drill bit is detachably connected with the driving end of the driving device, the drill bit is detachably installed at the lower end of the drill rod, and the driving device is used for driving the drill rod to drive the drill bit to rotate.

Further, elevating gear includes support, a lift section of thick bamboo and elevating system, the support is the cuboid structure, and its vertical setting is in the upper end of base, and with the connection can be dismantled to the base, a lift section of thick bamboo is the drum structure, and its cover is established outside the support, elevating system sets up on the support, it with a lift section of thick bamboo transmission is connected, and it can drive a lift section of thick bamboo is followed the length direction of support removes, drive arrangement with a lift section of thick bamboo can be dismantled and be connected.

Further, the lifting mechanism comprises an upper gear, a lower gear, a transmission chain and a second driving unit, the support is hollow, one side of the base close to the opening of the base is provided with two first through holes communicated with the inside of the base, and the two first through holes are respectively distributed at intervals up and down, the upper gear and the lower gear are correspondingly arranged in the two first through holes and are rotationally connected with the bracket, the gear surface of the transmission chain passes through the corresponding first through hole and extends out of the bracket, the transmission chain is arranged between the upper gear and the lower gear, and are respectively meshed with the upper gear and the lower gear, chain clamping teeth matched with the transmission chain are arranged on the inner wall of the lifting cylinder, the chain latch is fixedly connected with the transmission chain, and the second driving unit is in transmission connection with the upper gear and can drive the upper gear to drive the transmission chain and the lifting cylinder to move up and down.

Furthermore, the second driving unit is a Z-shaped lifting handle, the upper end of the lifting handle penetrates through the support and is in transmission connection with the upper gear, and the upper gear can be driven to rotate by the driving rotating shaft.

Further, be equipped with the bar spout that sets up along its length direction on the relative both sides side of support, the upper and lower both ends of bar spout all extend to and are close to the upper and lower both ends of support, be equipped with on the inner wall of a lift section of thick bamboo with two the ball subassembly that the bar spout corresponds the setting is two sets of ball subassembly follows respectively the circumference interval distribution of a lift section of thick bamboo to the embedding corresponds in the bar spout, ball subassembly can follow the correspondence the bar spout removes.

Further, the ball subassembly includes a plurality of balls that follow a lift section of thick bamboo axial evenly distributed, and a plurality of balls all imbed correspondingly in the bar spout.

Further, drive arrangement includes first drive unit, unit head and power shaft, the unit head sets up in the top of base open end, its pass through the connecting piece with the connection can be dismantled to the periphery of a lift section of thick bamboo, the upper end of unit head is equipped with the vertical second through-hole that runs through its setting, the coaxial setting in upper end of power shaft is in the second through-hole, and with the second through-hole rotates to be connected, the drilling rod is the round bar, and its inside cavity and upper end are uncovered, the lower extreme of power shaft passes the upper end of drilling rod stretches into in the drilling rod, and with the connection can be dismantled to the drilling rod, first drive unit detachable sets up the upper end of unit head, its drive end stretch into in the second through-hole with the power shaft transmission is connected, and can drive the power shaft drives the drilling rod rotates.

Further, first drive unit includes gasoline engine and gearbox, gearbox detachable installs the upper end of unit head, the gasoline engine is fixed the upper end of gearbox, its drive shaft passes the gearbox stretches into in the second through-hole, and with the power shaft transmission is connected, be equipped with clutch and derailleur in the gearbox, the clutch with the derailleur all sets up in the drive shaft of gasoline engine.

Furthermore, the base is of a U-shaped structure consisting of a cross beam and two bottom plates, the two bottom plates are arranged at two ends of the cross beam respectively and are detachably connected with the cross beam, a clamping groove vertically penetrating through the cross beam and matched with the support is formed in the middle of the cross beam, and the lower end of the support is detachably mounted in the clamping groove.

Furthermore, the outer wall of the drill rod is provided with second external threads distributed along the axial direction of the drill rod.

The utility model provides a beneficial effect that technical scheme brought is: a light rig of geological exploration suitable for high mountain, high altitude area, it has following beneficial effect:

(1) the drilling machine of the utility model has the advantages of simple structure, small volume, convenient operation, strong practicability, high working efficiency and the like;

(2) the drilling machine has high detachability, and most components are connected and fixed through the bolts and the threads, so the drilling machine is convenient to disassemble and assemble, has low implementation cost, can obviously improve the portability of the drilling machine, is convenient to separate and move, meets the drilling requirements of areas with high drilling difficulty, such as high mountains, high altitudes and the like, and reduces the drilling cost;

(3) the rig adopts the spiral drilling mode that need not water pump water supply to at the gyration in-process, the spiral that rises on the accessible drilling rod is carried out the rock powder from drilling in, in order to satisfy the water shortage area probing demand.

Drawings

FIG. 1 is a schematic structural diagram of a portable drilling machine for geological exploration, which is suitable for high mountain and high altitude areas;

fig. 2 is a schematic structural view of the bracket and the base of the present invention;

fig. 3 is a schematic structural view of the bracket and the base of the present invention;

fig. 4 is a schematic structural view of the lifting cylinder of the present invention;

fig. 5 is a schematic structural diagram of the power head of the present invention;

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, embodiments of the present invention will be further described below with reference to the accompanying drawings.

Referring to fig. 1-5, an embodiment of the present invention provides a portable drilling machine for geological exploration suitable for high mountains and high altitude areas, comprising a base, a drill rod 20, a drill bit 30, a lifting device and a driving device, wherein the base is in a "U" shape and horizontally arranged, the lifting device is used for driving the driving device to move along the length direction of the driving device, the lifting device comprises a support 40, a lifting cylinder 41 and a lifting mechanism, the support 40 is in a hollow rectangular body structure, vertically arranged at the upper end of the base and detachably connected with the base, the lifting mechanism is arranged on the support 40 and used for driving the driving device to move, the support 40 comprises an upper gear 42, a lower gear 43, a transmission chain 44 and a second driving unit 45, one side of the support 40 close to the base opening is provided with two first through holes (not shown in the figure) communicated with the interior thereof, the two first through holes are respectively distributed at intervals up and down, the upper gear 42 and the lower gear 43 are correspondingly arranged in the two first through holes, the gear surface of the upper gear 42 passes through the corresponding first through hole and extends out of the bracket 40, the transmission chain 44 is arranged between the upper gear 42 and the lower gear 43 and is meshed with the upper gear 42 and the lower gear 43, the lifting cylinder 41 is of a cylindrical structure and is sleeved outside the bracket 40 and is fixedly connected with the transmission chain 44, the second driving unit 45 is in transmission connection with the upper gear 42 and can drive the upper gear 42 to drive the transmission chain 44 and the lifting cylinder 41 to move up and down, the driving device comprises a first driving unit, a power head 50 and a power shaft 51, the power head 50 is arranged above the open end of the base and is fixedly connected with the lifting cylinder 41 through a connecting piece, its lower extreme is vertical to be equipped with power shaft 51, first drive unit sets up the upper end of unit head 50, and with the transmission of power shaft 51 is connected, and it can drive power shaft 51 rotates, drilling rod 20 is the round bar, and its inside cavity and upper end are uncovered, the coaxial cover of drilling rod 20 is established outside power shaft 51, and with power shaft 51 can dismantle the connection, drill bit 30 detachable installs the lower extreme of drilling rod 20.

In the present invention, the lower gear 43 is axially disposed in the horizontal direction, which is disposed in the bracket 40, a lower rotating shaft arranged along the width direction of the bracket 40 is arranged at the mounting position corresponding to the lower gear 43 in the bracket 40, two ends of the lower rotating shaft are rotationally connected with the inner wall of the corresponding side of the bracket 40, the lower gear 43 is coaxially sleeved on the lower rotating shaft, the gear surface of the gear extends out of the bracket 40 through the corresponding first through hole, correspondingly, the upper gear 42 is rotatably connected with the inner wall of the corresponding side of the bracket 40 through an upper rotating shaft arranged along the width direction of the bracket 40, the second driving unit 45 is a Z-shaped lifting handle, the upper end of the lifting handle penetrates through the bracket 40 and is fixedly connected with one end of the upper rotating shaft, under the action of external force, the lifting handle can drive the rotating shaft to drive the upper gear 42 to rotate, and the lifting handle can control the drill bit to lift, so that the required axial stress can be provided for the drill bit to drill downwards. In order to facilitate holding, the lifting handle is provided with an anti-slip sleeve (not shown in the figure). Under the action of the lifting device, the drill rod 20 can be driven to move up and down so as to adjust the height position of the drill rod 20, and further the drilling effect is realized. The utility model discloses not prescribing a limit to the structure of unit head 50, it can be cylinder structure or cuboid structure, corresponding, the utility model provides a unit head 50 is the cylinder structure. Rig, its base and support 40, unit head 50 and support 40 and first drive unit and unit head 50 all can carry out the split, can show the convenience that improves the rig and carry, satisfy mountain, high altitude area operation needs.

In the above embodiment, the base is a U-shaped structure composed of a cross beam 10 and two bottom plates 11, the two bottom plates 11 are rectangular structures, and are respectively disposed at two ends of the cross beam 10 and detachably connected to the cross beam 10, a clamping groove (not shown in the figure) vertically penetrating through the cross beam 10 and adapted to the bracket 40 is disposed in the middle of the cross beam 10, third threaded through holes (not shown in the figure) horizontally disposed on two sides of the cross beam 10 and communicated with the inside of the clamping groove are respectively disposed, the lower end of the bracket 40 extends into the clamping groove, a second bolt (not shown in the figure) is threadedly mounted in each third threaded through hole, and the bracket 40 can be fixed in the clamping groove by screwing the second bolts.

The utility model discloses in, bottom plate 11 with can dismantle the connection through the double-screw bolt between the crossbeam 10, the fixed connection mode that the double-screw bolt is fixed has easy dismounting and implementation cost low grade advantage, and it is prior art, no longer gives unnecessary details to its concrete connection method here. And the detachable connecting structure between the cross beam 10 and the bottom plate 11 can facilitate the disassembly, assembly and combination of the drilling machine, and improve the carrying convenience of the drilling machine. In order to increase the friction force between the bottom plate 11 and the ground, the bottom of the bottom plate 11 is provided with a W-shaped anti-slip pad.

In the above embodiment, the inner wall of the lifting cylinder 41 is provided with the chain latch 46 which is arranged along the axial direction and is matched with the transmission chain 44, and the chain latch 46 is fixedly connected with the transmission chain 44.

The utility model discloses in, be connected through the transmission of drive chain 44 with chain latch 46 to the realization drives reciprocating of a lift section of thick bamboo 41, and then reaches the purpose of adjustment unit head 50 and drilling rod 20 high position.

In the above embodiment, the two opposite side surfaces of the bracket 40 are provided with the strip-shaped sliding grooves 47 arranged along the length direction thereof, the upper and lower ends of the strip-shaped sliding grooves 47 extend to the positions close to the upper and lower ends of the bracket 40, the inner wall of the lifting cylinder 41 is provided with the ball assemblies correspondingly arranged with the two strip-shaped sliding grooves 47, the two sets of ball assemblies are respectively distributed along the circumferential direction of the lifting cylinder 41 at intervals and embedded into the corresponding strip-shaped sliding grooves 47, and the ball assemblies can move along the corresponding strip-shaped sliding grooves 47.

The utility model discloses in, the ball subassembly includes a plurality of balls 48 along 41 axial evenly distributed's of a lift section of thick bamboo, and a plurality of balls 48 all imbeds and correspond in the bar spout 47. The strip-shaped sliding groove 47 and the ball 48 can ensure the straightness of the moving track of the lifting cylinder 41, and prevent the lifting cylinder 41 from deviating in the track in the up-and-down moving process to influence the normal use of the drilling machine. The diameter of the balls 48 is adapted to the groove diameter of the strip-shaped runner 47.

In the above embodiment, the first driving unit includes a gasoline engine 53, the power head 50 is provided with a second through hole 54 vertically penetrating through the power head, the upper end of the power shaft 51 extends into the second through hole 54 and is rotatably connected with the second through hole 54, the gasoline engine 53 is arranged at the upper end of the power head 50, a clutch (not shown in the figure) and a transmission (not shown in the figure) are sequentially arranged on a driving shaft of the gasoline engine 53, and the driving shaft of the gasoline engine 53 extends into the second through hole 54 and is in transmission connection with the power shaft 51 and can drive the power shaft 51 to rotate.

The utility model discloses in, the utility model discloses a gasoline engine is as the power supply to abandon traditional hydraulic drive power supply, compare in the power supply of other types, the gasoline engine has characteristics such as simple structure is light, work load is little, the operation is stable. In order to improve the protection of the clutch and the transmission, a gearbox 55 is further arranged, the gearbox 55 is arranged at the upper end of the power head 50, a connecting base 56 matched with the second through hole 54 is arranged at the lower end of the gearbox 55, and the connecting base 56 is in threaded connection with the second through hole 54 so as to realize the detachable connection of the gearbox 55 and the power head 50. A third through hole (not shown in the figure) communicated with the second through hole 54 is formed in the connecting base 56, a fourth through hole (not shown in the figure) communicated with the inside of the gearbox 55 and the third through hole is vertically formed in the gearbox 55, the clutch and the transmission are arranged in the gearbox 55, and a driving shaft of the gasoline engine 53 penetrates through the third through hole and the fourth through hole respectively and extends into the second through hole 54. It should be noted that a clutch and a transmission are disposed on the driving shaft of the gasoline engine 53, so that the rotational speed of the gasoline engine 53 can be conveniently adjusted. And the method of connecting the clutch and transmission to the drive shaft of the gasoline engine 53 is applicable to the prior art.

In the above embodiment, the connecting member includes a first engaging lug 60 and a second engaging lug 61, the first engaging lug 60 is disposed on the outer wall of the lifting cylinder 41 along the radial direction of the lifting cylinder 41, and is provided with a plurality of first threaded through holes 62, the second engaging lug 61 is disposed on the outer wall of the power head 50 along the radial direction of the power head 50, and is provided with a second threaded through hole 63 matched with the plurality of first threaded through holes 62, the first threaded through hole 62 is communicated with the corresponding second threaded through hole 63 to form a threaded channel, each threaded channel is provided with a first bolt therein, and the first engaging lug 60 and the second engaging lug 61 can be fixedly connected by screwing the first bolt (not shown in the figure).

The utility model discloses in, bolt fastening's detachable connection has easy dismounting and implementation cost low grade advantage. As another embodiment of the detachable connection between the power head 50 and the lifting cylinder 41 of the present invention, it can also be detachably connected through a clamp.

In the above embodiment, the power shaft 51 is provided with a first external thread (not shown in the figure) arranged along the axial direction thereof, the inner wall of the drill rod 20 is provided with an internal thread (not shown in the figure) distributed along the axial direction thereof and matched with the first external thread, the lower end of the power shaft 51 penetrates through the upper end of the drill rod 20 and extends into the drill rod 20, and the drill rod 20 and the power shaft 51 are in threaded connection through the first external thread and the internal thread.

The utility model discloses in, threaded connection has easy dismounting and implementation cost low grade advantage.

In the above embodiment, the outer wall of the drill rod 20 is provided with the second external threads 21 distributed along the axial direction thereof, and the drill bit 30 is threadedly mounted on the lower end of the drill rod 20.

The utility model discloses in, threaded connection has easy dismounting and implementation cost low grade advantage, and second external thread 21 is favorable to carrying out the rock powder from drilling on the outer wall of drilling rod 20. The structure of the middle drill bit 30 of the present invention is suitable for the prior art.

In this document, the terms front, back, upper and lower are used to define the components in the drawings and the positions of the components relative to each other, and are used for clarity and convenience of the technical solution. It is to be understood that the use of the directional terms should not be taken to limit the scope of the claims.

The features of the embodiments and embodiments described herein above may be combined with each other without conflict.

The above description is only for the preferred embodiment of the present invention, and is not intended to limit the present invention, and any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention should be included within the protection scope of the present invention.

Claims (10)

1. A portable drilling machine for geological exploration suitable for high mountains and high altitude areas is characterized by comprising a base, a drill rod (20), a drill bit (30), a lifting device and a driving device, wherein the base is of a U-shaped structure, the lifting device is horizontally arranged, the lifting device is arranged at the upper end of the base and is detachably connected with the base, the driving device is arranged above the opening end of the base, and is in transmission connection with the lifting device, the lifting device is used for driving the driving device to move up and down to be far away from or close to the base, the driving end of the driving device is arranged downwards, the drill rod (20) is vertically arranged below the driving device, the upper end of the drill bit is detachably connected with the driving end of the driving device, the drill bit (30) is detachably arranged at the lower end of the drill rod (20), the driving device is used for driving the drill rod (20) to drive the drill bit (30) to rotate.

2. The portable geological exploration drilling machine suitable for high mountains and high altitude areas as claimed in claim 1, wherein the lifting device comprises a support (40), a lifting cylinder (41) and a lifting mechanism, the support (40) is of a rectangular body structure, is vertically arranged at the upper end of the base and is detachably connected with the base, the lifting cylinder (41) is of a cylindrical structure, is sleeved outside the support (40), the lifting mechanism is arranged on the support (40) and is in transmission connection with the lifting cylinder (41), and can drive the lifting cylinder (41) to move along the length direction of the support (40), and the driving device is detachably connected with the lifting cylinder (41).

3. The portable drilling machine for geological exploration suitable for high mountains and high altitude areas as claimed in claim 2, wherein the lifting mechanism comprises an upper gear (42), a lower gear (43), a transmission chain (44) and a second driving unit (45), the support (40) is hollow, one side of the support close to the base opening is provided with two first through holes communicated with the interior of the support, the two first through holes are respectively distributed at intervals up and down, the upper gear (42) and the lower gear (43) are correspondingly arranged in the two first through holes and are rotatably connected with the support (40), the gear surface of the upper gear passes through the corresponding first through holes and extends out of the support (40), the transmission chain (44) is arranged between the upper gear (42) and the lower gear (43) and is respectively meshed with the upper gear (42) and the lower gear (43), be equipped with on the inner wall of a lift section of thick bamboo (41) with chain latch (46) of drive chain (44) looks adaptation, chain latch (46) with drive chain (44) fixed connection, second drive unit (45) with go up gear (42) transmission and be connected, and can drive go up gear (42) drive chain (44) with a lift section of thick bamboo (41) reciprocates.

4. The portable geological exploration drilling machine suitable for high mountains and high altitude areas as claimed in claim 3, wherein the second driving unit (45) is a Z-shaped lifting handle, the upper end of the lifting handle penetrates through the bracket (40) to be in transmission connection with the upper gear (42), and the upper gear (42) can be driven to rotate by the driving shaft.

5. The portable drilling machine for geological exploration suitable for high mountains and high altitude areas as claimed in any one of claims 2 to 4, wherein strip-shaped sliding grooves (47) are formed in two opposite side surfaces of the support (40) along the length direction of the support, the upper ends and the lower ends of the strip-shaped sliding grooves (47) extend to be close to the upper ends and the lower ends of the support (40), ball assemblies corresponding to the two strip-shaped sliding grooves (47) are arranged on the inner wall of the lifting cylinder (41), the two groups of ball assemblies are respectively distributed along the circumferential direction of the lifting cylinder (41) at intervals and are embedded into the corresponding strip-shaped sliding grooves (47), and the ball assemblies can move along the corresponding strip-shaped sliding grooves (47).

6. The portable geological exploration drilling machine applicable to high mountains and high altitude areas as claimed in claim 5, wherein said ball assembly comprises a plurality of balls (48) uniformly distributed along the axial direction of the lifting cylinder (41), and each of the plurality of balls (48) is embedded in the corresponding strip-shaped sliding groove (47).

7. The portable geological exploration drilling machine applicable to high mountains and high altitude areas as claimed in claim 2, wherein the driving device comprises a first driving unit, a power head (50) and a power shaft (51), the power head (50) is arranged above the open end of the base and detachably connected with the periphery of the lifting cylinder (41) through a connecting piece, the upper end of the power head (50) is provided with a second through hole (54) vertically penetrating through the power head, the upper end of the power shaft (51) is coaxially arranged in the second through hole (54) and rotatably connected with the second through hole (54), the drill rod (20) is a round rod, the interior of the drill rod is hollow, the upper end of the drill rod is open, the lower end of the power shaft (51) penetrates through the upper end of the drill rod (20) to extend into the drill rod (20) and is detachably connected with the drill rod (20), the first driving unit is detachably arranged at the upper end of the power head (50), the driving end of the first driving unit extends into the second through hole (54) to be in transmission connection with the power shaft (51), and the first driving unit can drive the power shaft (51) to drive the drill rod (20) to rotate.

8. The portable geological exploration drilling machine suitable for high mountains and high altitude areas as claimed in claim 7, wherein the first driving unit comprises a gasoline engine (53) and a gearbox (55), the gearbox (55) is detachably mounted at the upper end of the power head (50), the gasoline engine (53) is fixed at the upper end of the gearbox (55), a driving shaft of the gasoline engine penetrates through the gearbox (55) to extend into the second through hole (54) and is in transmission connection with the power shaft (51), a clutch and a transmission are arranged in the gearbox (55), and the clutch and the transmission are both arranged on the driving shaft of the gasoline engine (53).

9. The portable geological exploration drilling machine suitable for high mountains and high altitude areas as claimed in claim 2, wherein the base is of a U-shaped structure consisting of a cross beam (10) and two bottom plates (11), the two bottom plates (11) are respectively arranged at two ends of the cross beam (10) and are detachably connected with the cross beam (10), a clamping groove vertically penetrating the cross beam (10) and matched with the support (40) is formed in the middle of the cross beam, and the lower end of the support (40) is detachably installed in the clamping groove.

10. The portable drilling machine for geological exploration suitable for high mountains and high altitude areas according to claim 1, characterized in that the outer wall of said drill rod (20) is provided with second external threads (21) axially distributed along the outer wall.

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