CN112717327A

CN112717327A - Dumbbell

Info

Publication number: CN112717327A
Application number: CN202110103199.0A
Authority: CN
Inventors: 赵利强
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-01-26
Filing date: 2021-01-26
Publication date: 2021-04-30

Abstract

The invention discloses a dumbbell, which comprises a handle and two groups of counterweight mechanisms, wherein the handle comprises a middle pipe, two telescopic rods in sliding fit with the middle pipe and two linear driving mechanisms arranged on the middle pipe, and the linear driving mechanisms correspond to the telescopic rods one by one and are used for controlling the telescopic rods to slide along the axial direction; the two groups of weight balancing mechanisms are symmetrically distributed at two ends of the middle tube, each weight balancing mechanism comprises a plurality of dumbbell pieces coaxial with the telescopic rod, a buckle assembly is arranged between every two adjacent dumbbell pieces and used for preventing the two adjacent dumbbell pieces from axially moving relatively, and when the telescopic rod is controlled by the linear driving mechanism to extend into the shaft holes of one or more dumbbell pieces, the corresponding number of dumbbell pieces are assembled at two ends of the middle tube through the telescopic rod; has the advantages of adjustable weight and convenient use.

Description

Dumbbell

Technical Field

The invention belongs to the technical field of fitness equipment, and particularly relates to a dumbbell.

Background

A dumbbell, named Dumbbell in English, is an auxiliary device for body-building exercises and mainly comprises a holding rod and a dumbbell sheet. The traditional dumbbells are divided into two types, one type is that a holding rod and a dumbbell sheet are integrally formed, the weight of the traditional dumbbell is not adjustable, and a plurality of sets of dumbbells with different weights are correspondingly purchased along with the gradual increase of the demand of a user on strength, so that the cost is high and the occupied space is large; the other type is that the holding rod and the dumbbell pieces are detachably connected through bolts, corresponding quantity of dumbbell pieces are configured at two ends of the holding rod according to actual requirements, the bolts need to be detached when the weight is adjusted each time, then the quantity of the dumbbell pieces is adjusted, and finally the dumbbell pieces are locked through the bolts, so that operation is troublesome.

Disclosure of Invention

The invention aims to provide a dumbbell with adjustable weight, which is convenient to use.

The technical scheme adopted by the invention for solving the technical problems is as follows: a dumbbell comprises a handle and two groups of counterweight mechanisms, wherein the handle comprises a middle pipe, two telescopic rods in sliding fit with the middle pipe and two linear driving mechanisms arranged on the middle pipe, and the linear driving mechanisms correspond to the telescopic rods one by one and are used for controlling the telescopic rods to slide along the axial direction; the two groups of weight balancing mechanisms are symmetrically distributed at two ends of the middle tube, each weight balancing mechanism comprises a plurality of dumbbell pieces coaxial with the telescopic rod, a buckle assembly is arranged between every two adjacent dumbbell pieces and used for preventing the two adjacent dumbbell pieces from moving axially relative to each other, and when the telescopic rod is controlled by the linear driving mechanism to extend into the shaft holes of one or more dumbbell pieces, the corresponding number of dumbbell pieces are assembled at two ends of the middle tube through the telescopic rod.

Preferably, the linear driving mechanism comprises a rotating seat with a first through hole, a limiting rod, a connecting seat with a second through hole and a locking piece, the middle tube is provided with two waist-shaped holes extending along the circumferential direction, the outer side wall of the telescopic rod is provided with an outer thread groove communicated with the waist-shaped holes, two dumbbell pieces closest to the middle tube are defined as inner dumbbell pieces respectively, the end part of the middle tube sequentially penetrates through the first through hole and the second through hole and then is detachably connected with the inner dumbbell pieces, the rotating seat is rotatably arranged on the middle tube, one side of the rotating seat is rotatably matched with one side of the connecting seat, the other side of the connecting seat is detachably connected with the inner dumbbell pieces, the locking piece is arranged between the connecting seat and the rotating seat and used for limiting the rotating seat to rotate, one end of the limiting rod is fixedly connected with the rotating seat, the other end of the limiting rod penetrates through the waist-shaped hole and then is inserted into the external thread groove, and when the locking piece is unlocked, the rotating seat rotates to enable the other end of the limiting rod to be in the external thread groove to move so as to adjust the extending length of the telescopic rod.

Preferably, a first sleeve coaxial with the intermediate pipe is arranged on one side of the rotating seat, a plurality of positioning notches distributed along the circumferential direction are formed in the top end of the first sleeve, a second sleeve sleeved on the outer side of the first sleeve is arranged on one side of the connecting seat, a lock hole is formed in the side wall of the second sleeve, the locking piece comprises a mounting seat fixedly arranged in the second sleeve and a lock block matched with the lock hole, a sliding groove extending along the radial direction, a sliding block in sliding fit with the sliding groove and a first compression spring are arranged on the mounting seat, the first compression spring is located between the groove bottom of the sliding groove and one end of the sliding block, the lock block is fixedly arranged on the other end of the sliding block, and when the sliding block is ejected out of the sliding groove by the first compression spring, the sliding block is in clamping fit with one of the positioning notches, and the locking block is inserted into the locking hole.

Preferably, a first guide post is arranged at the bottom of the sliding groove, a first counter bore with an opening facing the first guide post is formed in the sliding block, the first compression spring is sleeved on the first guide post, and one end of the first compression spring extends into the first counter bore.

Preferably, a coaxial circular ring is fixedly arranged in the first sleeve, a plurality of positioning grooves with the same number as the positioning notches are arranged in the circular ring in the circumferential direction, the positioning grooves correspond to the positioning notches in a one-to-one manner, a second guide column extending into the second sleeve is arranged on the connecting seat, a second counter bore, a second compression spring and a ball are arranged on the second guide column, one end of the second compression spring is in contact with the inner bottom surface of the second counter bore, and the other end of the second compression spring is connected with the ball and presses the ball into one positioning groove.

Preferably, the counterweight mechanism further comprises a support for placing the two groups of counterweight mechanisms, the lock hole is located on one side right below the second sleeve, two pushing convex blocks are arranged on the support and located right below the lock hole, when the counterweight mechanism is placed on the support, the pushing convex blocks are inserted into the second sleeve through the lock hole, the lock block is separated from the lock hole in the process, and the sliding block is separated from the positioning notch.

Preferably, the support comprises a base, two baffles and two connecting rods, one end of each connecting rod is fixedly connected with one baffle, the other end of each connecting rod penetrates through the base and is fixedly connected with the other baffle, the base, the baffles and the two connecting rods form a placing groove matched with the counterweight mechanism, the pushing lugs are fixedly arranged on the base, and the lower end of the connecting seat abuts against the base and enables the pushing lugs to be inserted into the locking holes.

Preferably, the upper end of the dumbbell sheet is provided with an upper mounting groove, the lower end of the dumbbell sheet is provided with a lower mounting groove, the buckle assembly comprises an upper connecting plate detachably connected with the upper mounting groove and a lower connecting plate detachably connected with the lower mounting groove, one side of the upper connecting plate, which is far away from the intermediate tube, is provided with a first limiting block, one side of the upper connecting plate, which is close to the intermediate tube, is provided with a first limiting groove in up-and-down sliding fit with the first limiting block, and the upper end of the first limiting groove penetrates through the upper end face of the upper connecting plate; one side of the lower connecting plate, which is close to the middle pipe, is provided with a second limiting block, one side of the lower connecting plate, which is far away from the middle pipe, is provided with a second limiting groove which is in vertical sliding fit with the second limiting block, and the lower end of the second limiting groove penetrates through the lower end face of the lower connecting plate.

Preferably, a first connecting block is arranged at the bottom of the upper mounting groove, a first pin hole is formed in the first connecting block, a first groove matched with the first connecting block in a clamping mode is formed in the lower end of the upper connecting plate, a second pin hole communicated with the first groove is formed in the side wall of the upper connecting plate, and a pin penetrates through the second pin hole and the first pin hole to fix the upper connecting plate to the dumbbell piece; the dumbbell piece is characterized in that a second connecting block is arranged at the bottom of the lower mounting groove, a third pin hole is formed in the second connecting block, a second groove matched with the second connecting block in a clamping mode is formed in the lower end of the lower connecting plate, a fourth pin hole communicated with the second groove is formed in the side wall of the lower connecting plate, and a pin penetrates through the fourth pin hole and the third pin hole to fix the lower connecting plate to the dumbbell piece.

Preferably, a third sleeve sleeved on the outer side wall of the middle pipe is arranged on the other side of the rotating seat, a lug is arranged on the outer side wall of the third sleeve, a fourth sleeve is arranged on the outer side of the middle pipe, positioning grooves are respectively arranged at two ends of the fourth sleeve, two ends of the fourth sleeve are respectively sleeved on the outer side wall of the third sleeve, and the lug is in clamping fit with the positioning grooves.

Compared with the prior art, the invention has the advantages that

1. The length of the telescopic rod extending out of the middle tube is adjusted through the linear driving mechanism, namely the length of the telescopic rod extending into the dumbbell piece shaft hole can be changed, so that the number of dumbbell pieces assembled at two ends of the middle tube is adjusted, two adjacent dumbbell pieces are prevented from axial relative movement through the buckle assembly, when a user takes up the dumbbell upwards through the handle, the dumbbell pieces inserted with the telescopic rods are limited at two ends of the middle tube, the dumbbell pieces not inserted with the telescopic rods are separated from the dumbbell pieces inserted with the telescopic rods, the purpose of adjusting the weight of the whole dumbbell is achieved, the adjusting process is free of complex dismounting action, and the dumbbell is convenient to use;

2. the other end of the limiting rod moves in the external thread groove by rotating the rotating seat, the telescopic rod moves along the axial direction in the process so as to adjust the extending length of the telescopic rod, the operation is simple, the use is convenient, and meanwhile, the maximum rotating angle of the rotating seat is controlled by arranging the waist-shaped hole on the middle pipe, so that the safety and the reliability are realized;

3. the two adjacent dumbbell pieces are connected and matched through the first limiting block, the first limiting groove, the second limiting block and the second limiting groove, the dumbbell pieces can only move upwards to be separated from the adjacent dumbbell pieces, the structure is matched with the telescopic rod for use, and the number of the dumbbell pieces at the two ends of the middle pipe can be simply and conveniently adjusted.

Drawings

FIG. 1 is a first schematic structural diagram of the present invention;

FIG. 2 is a schematic illustration of a partial explosion configuration of the present invention;

FIG. 3 is a schematic view of the structure of the intermediate pipe according to the present invention;

FIG. 4 is a schematic structural view of a rotary base according to the present invention;

FIG. 5 is a schematic view of a connecting socket according to the present invention;

FIG. 6 is a schematic cross-sectional view of the present invention;

FIG. 7 is a first structural schematic view of the locking element of the present invention;

FIG. 8 is a second structural view of the locking member of the present invention;

FIG. 9 is a second schematic structural view of the present invention;

FIG. 10 is a schematic view of the structure of the stand of the present invention;

FIG. 11 is a first schematic diagram of an exploded structure of a dumbbell sheet according to the present invention;

FIG. 12 is a second schematic diagram of the exploded structure of the dumbbell sheet of the present invention.

In the figure: 1. a grip; 11. an intermediate pipe; 111. a kidney-shaped hole; 12. a telescopic rod; 121. an outer thread groove; 13. a linear drive mechanism; 131. a rotating seat; 1311. a first perforation; 1312. a first sleeve; 1313. positioning the notch; 1314. a circular ring; 1315. a positioning groove; 1316. a third sleeve; 1317. a lug; 132. a limiting rod; 133. a connecting seat; 1331. a second perforation; 1332. a second sleeve; 1333. a lock hole; 1334. a second guide post; 1335. a second counterbore; 1336. a second compression spring; 1337. a ball bearing; 134. a locking member; 1341. a mounting seat; 1342. a locking block; 1343. a chute; 1344. a slider; 1345. a first compression spring; 1346. a first guide post; 1347. a first counterbore; 2. a counterweight mechanism; 21. a dumbbell sheet; 211. mounting a mounting groove; 212. a lower mounting groove; 213. a first connection block; 2131. a first pin hole; 214. a second connecting block; 2141. a third pin hole; 22. a buckle assembly; 221. an upper connecting plate; 2211. a first stopper; 2212. a first limit groove; 2213. a first groove; 2214. a second pin hole; 222. a lower connecting plate; 2221. a second limiting block; 2222. a second limit groove; 2223. a second groove; 2224. a fourth pin hole; 3. a support; 31. a base; 311. pushing the bump; 32. a baffle plate; 321. a third limiting block; 33. a connecting rod; 4. a fourth sleeve; 41. and (6) positioning a groove.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

The first embodiment is as follows: as shown in the figures, the dumbbell comprises a handle 1 and two groups of counterweight mechanisms 2, wherein the handle 1 comprises a middle pipe 11, two telescopic rods 12 in sliding fit with the middle pipe 11 and two linear driving mechanisms 13 arranged on the middle pipe 11, and the linear driving mechanisms 13 are in one-to-one correspondence with the telescopic rods 12 and are used for controlling the telescopic rods 12 to slide along the axial direction; two sets of counter weight mechanisms 2 symmetric distribution are at the both ends of well tube 11, counter weight mechanism 2 includes a plurality of dumbbell piece 21 coaxial with telescopic link 12, be provided with buckle subassembly 22 between two adjacent dumbbell piece 21, buckle subassembly 22 is used for preventing to take place axial relative movement between two adjacent dumbbell piece 21, when stretching into the shaft hole of one or more dumbbell piece 21 through sharp actuating mechanism 13 control telescopic link 12, the both ends of well tube 11 are assembled through telescopic link 12 to the dumbbell piece 21 of corresponding quantity.

In this embodiment, two cross bars 112 extending along the radial direction are fixedly disposed in the middle tube 11, the middle tube 11 at the position of the cross bar 112 is divided into two channels, one end of the telescopic rod 12 extends out of the middle tube 11 and into the shaft hole of the dumbbell sheet 21, the other end of the telescopic rod 12 is provided with an extension portion 122 penetrating through one channel, because the channel is non-circular, the extension portion 122 can only move along the axial direction, the telescopic rod 12 is prevented from rotating, and the cross bar 112 plays a role in limiting and guiding.

Example two: the rest of the embodiment is the same as the first embodiment, except that the linear driving mechanism 13 includes a rotating seat 131 having a first through hole 1311, a limiting rod 132, a connecting seat 133 having a second through hole 1331, and a locking member 134, the middle tube 11 is provided with two waist-shaped holes 111 extending along the circumferential direction, the outer side wall of the telescopic rod 12 is provided with an outer thread groove 121 communicated with the waist-shaped holes 111, two dumbbell pieces 21 closest to the middle tube 11 are defined as inner dumbbell pieces, the end of the middle tube 11 passes through the first through hole 1311 and the second through hole 1331 in sequence and is detachably connected with the inner dumbbell pieces, the rotating seat 131 is rotatably provided on the middle tube 11, one side of the rotating seat 131 is rotatably fitted with one side of the connecting seat 133, the other side of the connecting seat 133 is detachably connected with the inner dumbbell pieces, the locking member 134 is provided between the connecting seat 133 and the rotating seat 131 and is used for limiting the rotation of the rotating seat 131, one end of the limiting rod 132 is fixedly connected with the rotating seat 131, the other end of the limiting rod 132 penetrates through the waist-shaped hole 111 and then is inserted into the external thread groove 121, when the locking piece 134 is unlocked, the rotating seat 131 is rotated to enable the other end of the limiting rod 132 to move in the external thread groove 121 so as to adjust the extending length of the telescopic rods 12, wherein the spiral directions of the external thread grooves 121 on the two telescopic rods 12 are opposite.

In this embodiment, a first sleeve 1312 coaxial with the middle tube 11 is disposed on one side of the rotating seat 131, a plurality of positioning notches 1313 distributed along a circumferential direction are disposed at a top end of the first sleeve 1312, a second sleeve 1332 sleeved outside the first sleeve 1312 is disposed on one side of the connecting seat 133, a locking hole 1333 is disposed on a side wall of the second sleeve 1332, the locking member 134 includes a mounting seat 1341 fixedly disposed in the second sleeve 1332 and a locking block 1342 adapted to the locking hole 1333, a sliding groove 1343 extending in a radial direction, a sliding block 1344 slidably engaged with the sliding groove 1343, and a first compression spring 1345 is disposed on the mounting seat 1341, the first compression spring 1345 is located between a groove bottom of the sliding groove 1343 and one end of the sliding block 1344, the locking block 1342 is fixedly disposed at the other end of the sliding block 1344, when the sliding block 1344 is pushed out of the sliding groove 1343 by the first compression spring 1345, the sliding block 1344 is engaged with one positioning notch 1313, and the locking block 1342 is inserted into the locking hole, wherein, a plurality of positioning notches 1313 are distributed at equal intervals along the circumferential direction.

In this embodiment, a first guide post 1346 is disposed at a bottom of the sliding slot 1343, a first counter bore 1347 having an opening facing the first guide post 1346 is disposed on the slider 1344, the first compression spring 1345 is sleeved on the first guide post 1346, and one end of the first compression spring 1345 extends into the first counter bore 1347.

In this embodiment, a coaxial circular ring 1314 is fixedly arranged in the first sleeve 1312, a plurality of positioning grooves 1315 with the number equal to that of the positioning notches 1313 are arranged on the circular ring 1314 in the circumferential direction, the positioning grooves 1315 correspond to the positioning notches 1313 in a one-to-one manner, a second guide post 1334 extending into the second sleeve 1332 is arranged on the connecting seat 133, the axis of the second guide post 1334 is parallel to the axis of the middle tube 11, a second counter bore 1335, a second compression spring 1336 and a ball 1337 are arranged at the top end of the second guide post 1334, one end of the second compression spring 1336 is in contact with the inner bottom surface of the second counter bore 1335, the other end of the second compression spring 1336 is connected with the ball 1337 and presses the ball 1337 into one positioning groove 1315, wherein the plurality of positioning grooves 1315 are distributed at equal intervals in the circumferential direction, and the ball jumps among the plurality of positioning grooves 1315 during the rotation process of the rotary seat through the arrangement of the circular ring and the ball, the user can conveniently confirm whether the rotation is in place, and the use is more convenient.

Example three: the rest of the dumbbell is the same as the embodiment, but the dumbbell also comprises a support 3 for placing two groups of weight mechanisms 2, the lock hole 1333 is located on one side right below the second sleeve 1332, two pushing convex blocks 311 are arranged on the support 3, the pushing convex blocks 311 are located right below the lock hole 1333, when the weight mechanisms 2 are placed on the support 3, the pushing convex blocks 311 are inserted into the second sleeve 1332 through the lock hole 1333, in the process, the lock block 1342 is separated from the lock hole 1333, the sliding block 1344 is separated from the positioning notch 1313, the rotating seat 131 can be unlocked without manually pressing the lock block 1342, and the dumbbell is beneficial to further improving convenience, wherein the position of the pushing convex blocks 311 is staggered with the position of the first sleeve 1312, and the rotation of the first sleeve 1312 is prevented from being influenced.

In this embodiment, the support 3 includes a base 31, two baffles 32 and two connecting rods 33, one end of the connecting rod 33 is fixedly connected to one baffle 32, the other end of the connecting rod 33 passes through the base 31 and is fixedly connected to the other baffle 32, the base 31, the baffles 32 and the two connecting rods 33 form a placing groove adapted to the counterweight mechanism 2, the pushing protrusion 311 is fixedly disposed on the base 31, and the lower end of the connecting seat 133 abuts against the base 31 and the pushing protrusion 311 is inserted into the locking hole 1333.

In this embodiment, a third limiting block 321 is disposed on one side of the baffle 32 close to the base 31, a third limiting groove (not shown in the figure) in clamping fit with the third limiting block 321 is disposed on the lower end surface of the dumbbell sheet 21 closest to the baffle 32, and when part of the dumbbell sheet 21 is assembled to both ends of the middle tube 11 and separated from the placing groove, the baffle 32 limits the position of the dumbbell sheet 21 closest to the baffle 32 through the third limiting block 321 and the third limiting groove, so as to prevent the dumbbell sheet 21 from tilting or tipping.

Example four: the rest of the structure is the same as that of the first embodiment, and the structure is different in that an upper mounting groove 211 is formed in the upper end of the dumbbell sheet 21, a lower mounting groove 212 is formed in the lower end of the dumbbell sheet 21, the buckle assembly 22 comprises an upper connecting plate 221 detachably connected with the upper mounting groove 211 and a lower connecting plate 222 detachably connected with the lower mounting groove 212, a first limiting block 2211 is arranged on one side, away from the middle tube 11, of the upper connecting plate 221, a first limiting groove 2212 in up-and-down sliding fit with the first limiting block 2211 is arranged on one side, close to the middle tube 11, of the upper connecting plate 221, and the upper end of the first limiting groove 2212 penetrates through the upper end face; a second limit block 2221 is arranged on one side of the lower connecting plate 222 close to the middle tube 11, a second limit groove 2222 which is in up-and-down sliding fit with the second limit block 2221 is arranged on one side of the lower connecting plate 222 far away from the middle tube 11, the lower end of the second limit groove 2222 penetrates through the lower end face of the lower connecting plate 222, specifically, the width of the first limit block 2211 and the width of the second limit block 2221 are gradually increased from the bottom end to the top end, and the width of the first limit groove 2212 and the width of the second limit groove 2222 are gradually decreased from the bottom end to the top end.

In this embodiment, the first connecting block 213 is disposed at the bottom of the upper mounting groove 211, the first connecting block 213 is disposed with a first pin hole 2131, the lower end of the upper connecting plate 221 is disposed with a first groove 2213 engaged with the first connecting block 213, the sidewall of the upper connecting plate 221 is disposed with a second pin hole 2214 communicated with the first groove 2213, and the pin passes through the second pin hole 2214 and the first pin hole 2131 to fix the upper connecting plate 221 to the dumbbell sheet 21.

In this embodiment, the bottom of the lower mounting groove 212 is provided with a second connecting block 214, the second connecting block 214 is provided with a third pin hole 2141, the lower end of the lower connecting plate 222 is provided with a second groove 2223 engaged with the second connecting block 214, the side wall of the lower connecting plate 222 is provided with a fourth pin hole 2224 communicated with the second groove 2223, and the pin passes through the fourth pin hole 2224 and the third pin hole 2141 to fix the lower connecting plate 222 to the dumbbell sheet 21.

Example five: the rest of the structure is the same as the embodiment, and the difference is that the other side of the rotating seat 131 is provided with a third sleeve 1316 which is sleeved on the outer side wall of the middle tube 11, the outer side wall of the third sleeve 1316 is provided with a lug 1317, the outer side of the middle tube 11 is provided with a fourth sleeve 4, two ends of the fourth sleeve 4 are respectively provided with a positioning groove 41, two ends of the fourth sleeve 4 are respectively sleeved on the outer side wall of the third sleeve 1316, the lug 1317 is in clamping fit with the positioning grooves 41, the rotating seats 131 at two ends of the middle tube 11 are connected through the fourth sleeve 4, the rotating angles of the two rotating seats 131 can be synchronously adjusted by rotating the fourth sleeve 4, and the use is convenient.

The invention is described above with reference to the accompanying drawings, it is obvious that the implementation of the invention is not limited in the above manner, and it is within the scope of the invention to adopt various modifications of the inventive method concept and solution, or to apply the inventive concept and solution directly to other applications without modification.

Claims

1. The utility model provides a dumbbell, includes handle (1) and two sets of counter weight mechanisms (2), its characterized in that: the handle (1) comprises a middle pipe (11), two telescopic rods (12) in sliding fit with the middle pipe (11) and two linear driving mechanisms (13) arranged on the middle pipe (11), wherein the linear driving mechanisms (13) correspond to the telescopic rods (12) one by one and are used for controlling the telescopic rods (12) to slide along the axial direction; the two groups of weight mechanisms (2) are symmetrically distributed at two ends of the middle tube (11), each weight mechanism (2) comprises a plurality of dumbbell pieces (21) coaxial with the telescopic rod (12), a buckle assembly (22) is arranged between every two adjacent dumbbell pieces (21), each buckle assembly (22) is used for preventing the two adjacent dumbbell pieces (21) from moving axially relative to each other, and when the telescopic rods (12) are controlled by the linear driving mechanisms (13) to extend into the shaft holes of one or more dumbbell pieces (21), the corresponding quantity of dumbbell pieces (21) are assembled at two ends of the middle tube (11) through the telescopic rods (12).

2. A dumbbell according to claim 1, characterized in that: the linear driving mechanism (13) comprises a rotating seat (131) with a first through hole (1311), a limiting rod (132), a connecting seat (133) with a second through hole (1331) and a locking piece (134), wherein two waist-shaped holes (111) extending along the circumferential direction are formed in the middle tube (11), an outer thread groove (121) communicated with the waist-shaped holes (111) is formed in the outer side wall of the telescopic rod (12), two dumbbell pieces (21) closest to the middle tube (11) are defined as inner dumbbell pieces respectively, the end part of the middle tube (11) penetrates through the first through hole (1311) and the second through hole (1331) in sequence and then is detachably connected with the inner dumbbell pieces, the rotating seat (131) is rotatably arranged on the middle tube (11), and one side of the rotating seat (131) is in rotating fit with one side of the connecting seat (133), the other side of the connecting seat (133) is detachably connected with the inner dumbbell piece, the locking piece (134) is arranged between the connecting seat (133) and the rotating seat (131) and used for limiting the rotation of the rotating seat (131), one end of the limiting rod (132) is fixedly connected with the rotating seat (131), the other end of the limiting rod (132) penetrates through the waist-shaped hole (111) and then is inserted into the outer thread groove (121), and when the locking piece (134) is unlocked, the rotating seat (131) is rotated to enable the other end of the limiting rod (132) to move in the outer thread groove (121) so as to adjust the extending length of the telescopic rod (12).

3. A dumbbell according to claim 2, characterized in that: a first sleeve (1312) coaxial with the middle pipe (11) is arranged on one side of the rotating seat (131), a plurality of positioning notches (1313) distributed along the circumferential direction are arranged at the top end of the first sleeve (1312), a second sleeve (1332) sleeved outside the first sleeve (1312) is arranged on one side of the connecting seat (133), a lock hole (1333) is arranged on the side wall of the second sleeve (1332), the locking piece (134) comprises an installation seat (1341) fixedly arranged in the second sleeve (1332) and a lock block (1342) matched with the lock hole (1333), a sliding groove (1343) extending along the radial direction, a sliding block (1344) in sliding fit with the sliding groove (1343) and a first compression spring (1345) are arranged on the installation seat (1341), and the first compression spring (1345) is positioned between the groove bottom of the sliding groove (1343) and one end of the sliding block (1344), the locking piece (1342) is fixedly arranged at the other end of the sliding block (1344), when the sliding block (1344) is ejected out of the sliding groove (1343) by the first compression spring (1345), the sliding block (1344) is in clamping fit with one positioning notch (1313), and the locking piece (1342) is inserted into the locking hole (1333).

4. A dumbbell according to claim 3, characterized in that: a first guide post (1346) is arranged at the bottom of the sliding groove (1343), a first counter bore (1347) with an opening facing the first guide post (1346) is arranged on the sliding block (1344), the first compression spring (1345) is sleeved on the first guide post (1346), and one end of the first compression spring (1345) extends into the first counter bore (1347).

5. A dumbbell according to claim 3, characterized in that: the inner side of the first sleeve (1312) is fixedly provided with a coaxial circular ring (1314), the circular ring (1314) is provided with a plurality of positioning grooves (1315) with the number equal to that of the positioning notches (1313) along the circumferential direction, the positioning grooves (1315) correspond to the positioning notches (1313) one by one, the connecting seat (133) is provided with a second guide column (1334) extending into the second sleeve (1332), the second guide column (1334) is provided with a second counter bore (1335), a second compression spring (1336) and a ball (1337), one end of the second compression spring (1336) is in contact with the inner bottom surface of the second counter bore (1335), and the other end of the second compression spring (1336) is connected with the ball (1337) and presses the ball (1337) into one of the positioning grooves (1315).

6. A dumbbell according to claim 3, characterized in that: the counterweight mechanism is characterized by further comprising a support (3) for placing two groups of counterweight mechanisms (2), the lock hole (1333) is located on one side right below the second sleeve (1332), two pushing lugs (311) are arranged on the support (3), the pushing lugs (311) are located right below the lock hole (1333), when the counterweight mechanisms (2) are placed on the support (3), the pushing lugs (311) are inserted into the second sleeve (1332) through the lock hole (1333), the lock block (1342) is separated from the lock hole (1333) in the process, and the sliding block (1344) is separated from the positioning notch (1313).

7. A dumbbell according to claim 6, characterized in that: support (3) include base (31), two baffle (32) and two connecting rod (33), the one end and one of connecting rod (33) baffle (32) fixed connection, the other end of connecting rod (33) passes behind base (31) with another baffle (32) fixed connection, base (31) baffle (32) and two connecting rod (33) form with the standing groove of counter weight mechanism (2) looks adaptation, push up fixed the setting of lug (311) on base (31), the lower extreme butt of connecting seat (133) is in on base (31) and make push up lug (311) insert in lockhole (1333).

8. A dumbbell according to claim 1, characterized in that: an upper mounting groove (211) is formed in the upper end of the dumbbell sheet (21), a lower mounting groove (212) is formed in the lower end of the dumbbell sheet (21), the buckle assembly (22) comprises an upper connecting plate (221) detachably connected with the upper mounting groove (211) and a lower connecting plate (222) detachably connected with the lower mounting groove (212), a first limiting block (2211) is arranged on one side, away from the middle tube (11), of the upper connecting plate (221), a first limiting groove (2212) in up-and-down sliding fit with the first limiting block (2211) is formed in one side, close to the middle tube (11), of the upper connecting plate (221), and the upper end of the first limiting groove (2212) penetrates through the upper end face of the upper connecting plate (221); a second limiting block (2221) is arranged on one side, close to the middle pipe (11), of the lower connecting plate (222), a second limiting groove (2222) in up-and-down sliding fit with the second limiting block (2221) is arranged on one side, far away from the middle pipe (11), of the lower connecting plate (222), and the lower end of the second limiting groove (2222) penetrates through the lower end face of the lower connecting plate (222).

9. A dumbbell according to claim 8, characterized in that: a first connecting block (213) is arranged at the bottom of the upper mounting groove (211), a first pin hole (2131) is formed in the first connecting block (213), a first groove (2213) in clamping fit with the first connecting block (213) is formed in the lower end of the upper connecting plate (221), a second pin hole (2214) communicated with the first groove (2213) is formed in the side wall of the upper connecting plate (221), and a pin penetrates through the second pin hole (2214) and the first pin hole (2131) to fix the upper connecting plate (221) to the dumbbell sheet (21);

the tank bottom of lower mounting groove (212) is provided with second connecting block (214), be provided with third pinhole (2141) on second connecting block (214), the lower extreme of lower connecting plate (222) be provided with second connecting block (214) joint complex second recess (2223), be provided with down on the lateral wall of connecting plate (222) with fourth pinhole (2224) of second recess (2223) intercommunication, the pin passes fourth pinhole (2224) will behind third pinhole (2141) lower connecting plate (222) is fixed to on dumbbell piece (21).

10. A dumbbell according to claim 2, characterized in that: the other side of rotating seat (131) is provided with the cover and is in third sleeve (1316) on well pipe (11) lateral wall, be provided with lug (1317) on the lateral wall of third sleeve (1316), the outside of well pipe (11) is provided with fourth sleeve (4), the both ends of fourth sleeve (4) are provided with constant head tank (41) respectively, the both ends of fourth sleeve (4) are overlapped respectively on the lateral wall of third sleeve (1316), just lug (1317) with constant head tank (41) joint cooperation.