CN209850751U - Clamping device for clamping inner wall of test piece - Google Patents

Abstract

The utility model relates to a clamping device for clamping the inner wall of a test piece, comprising: a shell, a bevel gear disc support body, a bevel gear disc, a bevel gear disc bearing, a small bevel gear, a small bevel gear shaft, and a small bevel gear bearing , Block cover, flange type connection body, cylindrical external gear ring, cylindrical external gear ring bearing, small cylindrical gear shaft mounting body, cylindrical ring type connecting body, small cylindrical gear, small cylindrical gear shaft, small cylindrical gear bearing, connection Rod, claw, guide base, self-locking device; a clamping device for clamping the inner wall of the test piece of the utility model cooperates with the ratchet and the ratchet of the self-locking device, thereby completing the clamping device Self-locking, so that the clamping device has the function of self-locking, through a series of transmission mechanisms, the arc-shaped end of the claw is pushed to the central axis, and the clamping work of the specimen is completed. It has a simple and compact structure. , good workmanship, easy operation and so on.

Description

A clamping device for clamping the inner wall of a test piece

technical field

The utility model relates to a clamping device, in particular to a clamping device for clamping the inner wall of a test piece.

Background technique

Various clamping devices are used in human life and work, and the application range of clamping devices is becoming wider and wider. Clamping device refers to the device used to fix the processing object in the process of mechanical manufacturing so that it can occupy the correct position to accept construction or inspection, also known as fixture. In a broad sense, in any process in the process, the device used to install the workpiece quickly, conveniently and safely can be called a clamping device. The clamping device is an indispensable process equipment in mechanical processing. It can play the following roles: to ensure that the processing accuracy requirements are met stably and reliably; to shorten the processing time and improve labor productivity; to reduce production costs; to reduce the labor intensity of the operator ; It can be processed by operators with lower technical levels; it can expand the range of machine tools. There are a variety of clamping devices on the market, such as: welding fixtures, inspection fixtures, assembly fixtures, machine tool fixtures, etc., but most of the clamping devices have various problems, for example: for cylindrical ring test pieces, Only the outer wall of the test piece can be clamped, but the inner wall of the test piece cannot be clamped; the clamping device has complex structure, poor reliability, low precision, poor adaptability, etc. In order to solve many disadvantages of the clamping devices on the market, the utility model designs this clamping device which is easy to operate, elegant in appearance and high in precision for clamping the inner wall of the test piece.

Contents of the invention

The purpose of this utility model is to design and manufacture a clamping device for clamping the inner wall of a test piece which is simple in structure, compact in structure, good in manufacturability, convenient in operation, high in precision, safe and practical.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: a clamping device for clamping the inner wall of the test piece, including: a shell, a bevel disc support body, a bevel disc, a bevel disc bearing, a small cone Gear, pinion bevel gear shaft, pinion bevel gear bearing, cover, flange connection body, cylindrical external ring gear, cylindrical external gear ring bearing, small cylindrical gear shaft installation body, cylindrical ring type connection body, small cylindrical gear, Small cylindrical gear shaft, small cylindrical gear bearing, connecting rod, claw, guide base, self-locking device; the support body of the bevel gear is connected with the bevel gear through the bevel gear bearing, and the bevel gear The chainring meshes with the bevel pinion gear, the bevel pinion gear is fixedly connected to the bevel pinion gear shaft through a spline, and the bevel pinion gear shaft is connected to the housing through the bevel pinion gear bearing; The support body of the bevel tooth disc is fixedly connected with the cover by screws, the cover is fixedly connected with the shaft mounting body of the small cylindrical gear by screws, and the shaft mounting body of the small cylindrical gear is connected with the cylindrical ring The connecting body is fixedly connected to each other by screws, the cylindrical ring connecting body and the shell are fixedly connected to each other by screws; the bevel tooth plate and the flange connecting body are fixedly connected to each other by screws, and the flange The disc connecting body and the cylindrical external gear ring are fixedly connected to each other by screws, the cylindrical external gear ring and the small cylindrical gear shaft mounting body are connected to each other through the cylindrical external gear gear bearing, and the cylindrical external gear gear and the The small cylindrical gear is meshed, the small cylindrical gear and the small cylindrical gear shaft are connected to each other through the small cylindrical gear bearing, and the small cylindrical gear shaft and the small cylindrical gear shaft mounting body are fixedly connected to each other by welding; The eccentric part of the small cylindrical gear is hinged to one end of the connecting rod, the other end of the connecting rod is hinged to one end of the claw, and the other end of the claw passes through the guide base, and the The claw and the guide base are slidingly connected by clearance fit, and the guide base is welded on the edge of the small cylindrical gear shaft mounting body; the self-locking device is located between the shell and the small bevel gear, The ratchet of the self-locking device is mounted on the pinion gear shaft through a spline, the base of the self-locking device is fixedly connected with the housing through screws, and the adjusting screw of the self-locking device is connected with the housing Connected by threads; the shell, the bevel gear support body, the bevel gear, the bevel gear bearing, the cover, the flange connection body, the cylindrical outer gear , the axes of the cylindrical external ring gear bearing, the small cylindrical gear shaft mounting body and the cylindrical ring type connecting body are on the same straight line; the small bevel gear, the small bevel gear shaft, the small bevel There are three sets of gear bearings, the small cylindrical gear, the small cylindrical gear shaft, the small cylindrical gear bearing, the connecting rod, the claw, the guide base and the self-locking device. The same straight line equally divides the distribution.

Further, the outer casing is a hollow cylindrical structure, and one end surface of the cylinder is removed, and the other end surface is provided with three threaded holes equally divided around the axis, and the outer casing is provided with the threaded holes One end of one end is connected with one end of the cylindrical ring type connecting body by screws; three circular through holes I are separated on the side of the cylinder, and the axes of the three circular through holes I are on the same plane I , the plane I is parallel to the two end faces, the plane I is located on one side of the central symmetry plane of the two end faces, and is close to the side of the removed end face; on the side of the cylinder There are three threaded through holes, the axes of the three threaded through holes are on the same plane II, and the plane II is located next to the plane I; there are three circular through holes on the side of the cylinder II, the centers of the three circular through holes II are on the same plane III, and the plane III is symmetrical to the plane I with respect to the central symmetry plane of the two end faces.

Further, the self-locking device includes: a base, a spring, a support frame, an adjusting screw, a pawl, and a ratchet; the base is a cuboid structure, and is fixed on the inner side of the housing by screws, and the base One end of the side of the seat is welded with the spring, and the other end is welded with the support frame; the support frame is a square truss structure, the lower bottom surface end of the support frame is welded on the base, and the upper bottom surface end is hinged On one side of the middle of the ratchet, and away from the teeth of the ratchet; the inside of one end away from the teeth of the ratchet is fitted with the adjusting screw, which consists of a screw, a cylinder and the round table are fixedly installed together by threads in turn, and the outer shell of the cylinder and the round table is glued with a high-resilience elastomer material, and the screw of the adjusting screw is connected with the thread of the shell. The through holes are connected by threads, and the outer casing of the cylinder of the adjusting screw and the outer casing of the round table are in contact with the inside of one end away from the teeth of the pawl; one end of the spring is welded on the base , the other end is welded on the other side of the middle of the pawl, and is close to the side of the teeth of the pawl; the end of the tooth close to the pawl is fitted with the ratchet, and the ratchet passes through the flower The key is mounted on one end of the bevel pinion shaft and is close to the bevel pinion end.

Further, the bevel gear support body is located inside one end of the housing, and one end of the housing is the end from which the end face is removed; the bevel gear support body is a flange structure, and the ring The disc 1 and the inner hollow cylinder 1 whose two end faces are removed are connected to each other by welding, and one end of the inner hollow cylinder 1 has a stepped circular groove, and the end with the stepped circular groove is Away from the end of the annular disc 1.

Further, the flange-type connecting body is a flange-type structure, and the annular disc II and the inner hollow cylinder II are connected to each other by welding, and one end face of the cylinder II is removed, The other end surface has a circular hole, and the one end surface with the circular hole is an end surface far away from the annular disk II.

Further, the mounting body of the small spur gear shaft is a flange structure, and the ring disc III and the inner hollow cylinder III whose two ends are removed are connected together by welding.

Further, the bottom surface of one end of the claw is an arc-shaped structure, and one end of the claw is the end for clamping the test piece.

Further, one end of the bevel pinion shaft has an inner hexagonal hole, and one end of the bevel pinion shaft is the end where the bevel pinion bearing is installed.

A clamping device for clamping the inner wall of the test piece is implemented according to the utility model, and its beneficial effects are as follows:

(1) The utility model is a clamping device for clamping the inner wall of the test piece. The small bevel gear shaft is rotated counterclockwise with an Allen wrench, and the small bevel gear shaft rotates, thereby driving the small bevel gear to rotate ; the rotation of the bevel pinion drives the bevel gear to rotate, and then drives the flange connection body to rotate; the rotation of the flange connection body drives the cylindrical outer ring gear to rotate, and then drives the flange connection body to rotate; The small cylindrical gear rotates; the rotation of the small cylindrical gear drives the connecting rod to move, and then drives the claws to move in a straight line, so that the arc-shaped ends of the claws move away from the central axis and move toward the inner wall of the test piece. With the increase of the distance between the arc-shaped ends of the jaws, the clamping work of the test piece is completed, and it has the advantages of simple and compact structure, good manufacturability, and convenient operation.

(2) A clamping device for clamping the inner wall of the test piece. The adjusting screw is screwed clockwise by hand, and the adjusting screw moves downward while rotating, and the round table side of the adjusting screw pushes the The pawl rotates, and then the pawl and the ratchet cooperate with each other, so that the pinion bevel gear shaft can only rotate counterclockwise, that is, the pawl can only move in a direction away from the central axis, and cannot move in a direction close to the central axis. Direction movement, thereby completing the self-locking of the clamping device, so that the clamping device has a self-locking function.

Description of drawings

Fig. 1 is an appearance diagram of a clamping device for clamping the inner wall of a test piece according to the utility model;

Fig. 2 is a shell-removed structure diagram of a clamping device for clamping the inner wall of a test piece according to the present invention;

Fig. 3 is an exploded view of a shell-removed structure of a clamping device for clamping the inner wall of a test piece according to the present invention;

Fig. 4 is a clamping working principle diagram of a clamping device for clamping the inner wall of the test piece according to the utility model;

Fig. 5 is a structural diagram of a self-locking device of a clamping device for clamping the inner wall of a test piece according to the present invention;

Fig. 6 is a two-dimensional diagram of a flange-type connecting body of a clamping device for clamping the inner wall of a test piece according to the present invention;

In the figure: shell-1, bevel gear support body-2, bevel gear disc-3, bevel gear bearing-4, pinion bevel gear-5, pinion bevel gear shaft-6, pinion bevel gear bearing-7, cover -8. Flange connection body-9, Cylindrical external ring gear-10, Cylindrical external gear ring bearing-11, Small cylindrical gear shaft installation body-12, Cylindrical ring type connection body-13, Small cylindrical gear-14, Small cylindrical gear shaft-15, small cylindrical gear bearing-16, connecting rod-17, claw-18, guide base-19, self-locking device-20, base-201, spring-202, support frame-203, Adjust screw-204, pawl-205, ratchet-206.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described further.

As shown in Figures 1, 2, 3, 4, 5, and 6, a clamping device for clamping the inner wall of a test piece includes: a shell 1, a bevel disc support body 2, a bevel disc 3, and a bevel disc Bearing 4, small bevel gear 5, small bevel gear shaft 6, small bevel gear bearing 7, cover 8, flange connection body 9, cylindrical external ring gear 10, cylindrical external ring gear bearing 11, small cylindrical gear shaft installation Body 12, cylindrical ring type connecting body 13, small cylindrical gear 14, small cylindrical gear shaft 15, small cylindrical gear bearing 16, connecting rod 17, claw 18, guide base 19, self-locking device 20; Support body 2 is connected with described bevel gear plate 3 through described bevel gear plate bearing 4, and described bevel gear plate 3 is meshed with described pinion bevel gear 5, and described pinion bevel gear 5 is splined with described pinion gear The bevel gear shaft 6 is fixedly connected, and the bevel pinion shaft 6 is connected to the housing 1 through the bevel pinion bearing 7; the bevel gear support body 2 is fixedly connected to the cover 8 by screws , the cover 8 is fixedly connected to the small cylindrical gear shaft mounting body 12 by screws, the small cylindrical gear shaft mounting body 12 and the cylindrical ring type connecting body 13 are fixedly connected to each other by screws, and the cylindrical ring The connecting body 13 and the shell 1 are fixedly connected to each other by screws; the bevel gear plate 3 and the flange connecting body 9 are fixedly connected to each other by screws; The outer ring gear 10 is fixedly connected to each other by screws, and the cylindrical outer ring gear 10 and the small cylindrical gear shaft mounting body 12 are connected to each other through a cylindrical outer ring gear bearing 11, and the cylindrical outer ring gear 10 and the small cylindrical gear 14, the small cylindrical gear 14 and the small cylindrical gear shaft 15 are connected to each other through the small cylindrical gear bearing 16, and the small cylindrical gear shaft 15 and the small cylindrical gear shaft mounting body 12 are fixed to each other by welding Connection; the eccentric part of the small cylindrical gear 14 is hinged to one end of the connecting rod 17, the other end of the connecting rod 17 is hinged to one end of the claw 18, and the other end of the claw 18 passes through The guide base 19, the claw 18 is slidingly connected with the guide base 19 through a clearance fit, and the guide base 19 is welded on the edge of the small cylindrical gear shaft installation body 12; the self-locking device 20 is located between the housing 1 and the bevel pinion 5, the ratchet 206 of the self-locking device 20 is mounted on the bevel pinion shaft 6 through a spline, and the base 201 of the self-locking device 20 is passed through The screw is fixedly connected with the shell 1, and the adjusting screw 204 of the self-locking device 20 is connected with the shell 1 by threads; , the bevel gear disc bearing 4, the cover 8, the flanged connecting body 9, the cylindrical outer gear ring 10, the cylindrical outer gear gear bearing 11, the small cylindrical gear shaft mounting body 12 and the axis of the cylindrical ring type connector 13 are on the same straight line; the bevel pinion 5, the bevel pinion shaft 6, the bevel pinion bearing 7, the bevel pinion 14, the bevel pinion small cylindrical tooth There are three sets of wheel shaft 15, the small cylindrical gear bearing 16, the connecting rod 17, the claw 18, the guide base 19 and the self-locking device 20, which are equally distributed around the same straight line .

Further, the housing 1 is a hollow cylindrical structure, and one end surface of the cylinder is removed, and the other end surface is provided with three threaded holes equally divided around the axis, and the housing 1 is provided with the One end of the threaded hole is connected with one end of the cylindrical ring type connecting body 13 by a screw; three circular through holes I are all separated on the side of the cylinder, and the axes of the three circular through holes I are at On the same plane I, the plane I is parallel to the two end faces, the plane I is located on one side of the central symmetry plane of the two end faces, and is close to the side of the removed end face; on the cylinder There are three threaded through holes on the side of the cylinder, the axes of the three threaded through holes are on the same plane II, and the plane II is located next to the plane I; three circles are separated on the side of the cylinder The centers of the three circular through holes II are on the same plane III, and the plane III is symmetrical to the plane I with respect to the central symmetry plane of the two end faces.

Further, the self-locking device 20 includes: a base 201, a spring 202, a support frame 203, an adjustment screw 204, a pawl 205, and a ratchet 206; 1, one end of the side of the base 201 is welded with the spring 202, and the other end is welded with the support frame 203; The bottom surface end is welded on the base 201, and the upper bottom surface end is hinged on the middle side of the ratchet 205, and is the side away from the teeth of the ratchet 205; The adjusting screw 204 is mounted on the inner side of one end, and the adjusting screw 204 is fixed and installed together by a screw, a cylinder and a round platform in sequence, and the outside of the cylinder and the round platform are glued together and made of an elastomer material with high resilience. The shell of the said adjusting screw 204 is threadedly connected with the threaded through hole of the shell 1. The inside of one end of the teeth of the ratchet 205 is in contact with each other; one end of the spring 202 is welded on the base 201, and the other end is welded on the other side of the middle of the ratchet 205, and is close to the ratchet. 205 tooth side; near one end of the teeth of the ratchet 205 is fitted with the ratchet 206, the ratchet 206 is mounted on one end of the pinion bevel gear shaft 6 through a spline, and is close to the pinion One end of bevel gear 5.

Further, the bevel gear support body 2 is located inside one end of the housing 1, and one end of the housing 1 is the end with the end face removed; the bevel gear support body 2 is a flange structure , the inner hollow cylinder I which is removed from the ring disk I and the two end faces is connected to each other by welding, and one end of the inner hollow cylinder I has a stepped circular groove, and a stepped circular groove One end of the groove is an end far away from the annular disk I; the flange-type connecting body 9 is a flange-type structure, and the annular disk II and the inner hollow cylinder II are connected to each other by welding, and One end face of the cylinder II is removed, and the other end face has a round hole, and the end face with the round hole is an end face away from the ring disc II; the small cylindrical gear shaft mounting body 12 It is a flange plate structure, and the circular disc III and the inner hollow cylinder III whose two ends are removed are connected together by welding; the bottom surface of one end of the claw 18 is an arc structure, and the claw One end of 18 is an end for clamping the test piece; one end of the bevel pinion shaft 6 has an inner hexagonal hole, and one end of the bevel pinion shaft 6 is the end for installing the bevel pinion bearing 7 .

As shown in Figures 1, 2, 3, 4, 5, and 6, the specific steps of the working method of a clamping device for clamping the inner wall of the test piece of the present invention are as follows:

Install according to the installation requirements, the bevel gear support body 2 is connected with the bevel gear 3 through the bevel gear bearing 4, the bevel gear 3 is meshed with the small bevel gear 5, the Bevel pinion 5 is fixedly connected with described bevel pinion shaft 6 by spline, and bevel pinion shaft 6 is mutually connected with described shell 1 by described bevel pinion bearing 7; 2. The cover 8 is fixedly connected to each other by screws, the cover 8 is fixedly connected to the small cylindrical gear shaft mounting body 12 by screws, and the small cylindrical gear shaft mounting body 12 is connected to the cylindrical ring The bodies 13 are fixedly connected to each other by screws, and the cylindrical ring-type connecting body 13 and the shell 1 are fixedly connected to each other by screws; the bevel gear plate 3 and the flange-type connecting body 9 are fixedly connected to each other by screws, The flange-type connecting body 9 and the cylindrical external ring gear 10 are fixedly connected to each other by screws, and the cylindrical external ring gear 10 and the small cylindrical gear shaft mounting body 12 are connected to each other through a cylindrical external ring gear bearing 11, The cylindrical external ring gear 10 is meshed with the small cylindrical gear 14, the small cylindrical gear 14 and the small cylindrical gear shaft 15 are connected to each other through the small cylindrical gear bearing 16, and the small cylindrical gear shaft 15 is connected to the small cylindrical gear shaft 15. The small cylindrical gear shaft installation body 12 is fixedly connected to each other by welding; the eccentric part of the small cylindrical gear 14 is hinged to one end of the connecting rod 17, and the other end of the connecting rod 17 is connected to the claw 18 One end of the claw 18 is hinged, the other end of the claw 18 passes through the guide base 19, the claw 18 and the guide base 19 are slidably connected by clearance fit, and the guide base 19 is welded on the small The edge of the cylindrical gear shaft mounting body 12; the self-locking device 20 is placed between the housing 1 and the small bevel gear 5, and the ratchet 206 of the self-locking device 20 is mounted on the small cone by a spline On the gear shaft 6, the base 201 of the self-locking device 20 is fixedly connected with the shell 1 by screws, and the adjusting screw 204 of the self-locking device 20 is connected with the shell 1 by threads; 1. The bevel gear support 2, the bevel gear 3, the bevel gear bearing 4, the cover 8, the flange connector 9, the cylindrical outer gear 10, The axes of the cylindrical external ring gear bearing 11, the small cylindrical gear shaft mounting body 12 and the cylindrical ring type connecting body 13 are on the same straight line; the pinion bevel gear 5, the pinion bevel gear shaft 6 , the small bevel gear bearing 7, the small cylindrical gear 14, the small cylindrical gear shaft 15, the small cylindrical gear bearing 16, the connecting rod 17, the claw 18, the guide base 19 There are three sets respectively of the self-locking device 20, which are equally distributed around the same straight line; The body 12 and the cylindrical ring-type connector 13 form a stator system, and the stator system does not rotate around the central axis during the process of tightening the test piece; the bevel gear plate 3 and the flange-type connector 9 It forms a rotor system with the cylindrical external ring gear 10, and the rotor system rotates around the central axis during the process of tightening the test piece.

When clamping the test piece, the adjusting screw 204 is screwed clockwise by hand, and the adjusting screw 204 moves downward while rotating, and the round table side of the adjusting screw 204 pushes the pawl 205 to rotate, and then the adjusting screw 204 rotates. The pawl 205 cooperates with the ratchet 206 so that the bevel pinion shaft 6 can only rotate counterclockwise, that is, the pawl 18 can only move in a direction away from the central axis, and cannot move in a direction close to the central axis. Thus, the self-locking setting of the clamping device is completed.

Rotate the pinion bevel gear shaft 6 counterclockwise with an Allen wrench, the pinion bevel gear shaft 6 rotates, and then drives the pinion bevel gear 5 to rotate; the rotation of the pinion bevel gear 5 drives the bevel gear plate 3 to rotate , and then drive the flange plate connecting body 9 to rotate; the rotation of the flange plate connecting body 9 drives the cylindrical outer ring gear 10 to rotate, and then drives the small cylindrical gear 14 to rotate; the small cylindrical gear 14 drives the connecting rod 17 to move, and then drives the jaw 18 to move linearly, so that the arc-shaped end of the jaw 18 moves away from the central axis and moves toward the inner wall of the test piece. The increase of distance from the arc end completes the clamping work of the specimen.

When loosening the test piece, screw the adjusting screw 204 counterclockwise by hand, and the adjusting screw 204 moves upward while rotating, and the round table side of the adjusting screw 204 is far away from the pawl 205, and the compressed The spring 202 stretches freely, thereby promoting the rotation of the ratchet 205, and then the ratchet 205 and the ratchet 206 are separated from each other, so that the situation that the bevel pinion shaft 6 can only rotate counterclockwise is removed, and the card The pawl 18 can move towards the direction close to the central axis, so as to complete the unlocking setting of the clamping device.

Rotate the small bevel gear shaft 6 clockwise with an Allen wrench, the small bevel gear shaft 6 rotates, and then drives the small bevel gear 5 to rotate; the rotation of the small bevel gear 5 drives the bevel gear plate 3 to rotate , and then drive the flange plate connecting body 9 to rotate; the rotation of the flange plate connecting body 9 drives the cylindrical outer ring gear 10 to rotate, and then drives the small cylindrical gear 14 to rotate; the small cylindrical gear The rotation of 14 drives the movement of the connecting rod 17, and then drives the jaw 18 to move in a straight line, so that the arc-shaped end of the jaw 18 is close to the central axis and moves away from the inner wall of the test piece. The arc-shaped end of the approach increases to complete the loosening of the specimen.

The above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present utility model shall be included in this utility model. within the scope of protection of utility models.

Claims (8)

1. A clamping device for clamping the inner wall of a test piece, characterized in that it comprises: a housing (1), a bevel gear support (2), a bevel gear (3), and a bevel gear bearing (4) , Bevel pinion gear (5), Bevel pinion gear shaft (6), Bevel pinion gear bearing (7), Cover (8), Flange connector (9), Cylindrical outer ring gear (10), Cylindrical outer gear Ring gear bearing (11), small cylindrical gear shaft mounting body (12), cylindrical ring type connector (13), small cylindrical gear (14), small cylindrical gear shaft (15), small cylindrical gear bearing (16), connection Rod (17), claw (18), guide base (19), self-locking device (20); said bevel gear support body (2) connects with said bevel gear through said bevel gear bearing (4) The disc (3) is connected, the bevel gear disc (3) is meshed with the bevel pinion gear (5), and the bevel pinion gear (5) is fixed to the bevel pinion gear shaft (6) through a spline connected, the bevel pinion shaft (6) is interconnected with the housing (1) through the bevel pinion bearing (7); the bevel gear support (2) is connected to the cover (8) ) are fixedly connected to each other, and the cover (8) is fixedly connected to the small cylindrical gear shaft mounting body (12) by screws, and the small cylindrical gear shaft mounting body (12) is connected to the cylindrical ring type connecting body ( 13) are fixedly connected to each other by screws, and the cylindrical ring type connecting body (13) and the shell (1) are fixedly connected to each other by screws; the bevel gear plate (3) and the flanged plate connecting body (9 ) are fixedly connected to each other by screws, the flanged connecting body (9) and the cylindrical external gear (10) are fixedly connected to each other by screws, and the cylindrical external gear (10) and the small cylindrical gear shaft The mounting body (12) is connected to each other through a cylindrical outer ring gear bearing (11), the cylindrical outer ring gear (10) is meshed with the small cylindrical gear (14), and the small cylindrical gear (14) is connected to the small cylindrical gear (14). The cylindrical gear shaft (15) is connected to each other through the small cylindrical gear bearing (16), and the small cylindrical gear shaft (15) and the small cylindrical gear shaft mounting body (12) are fixedly connected to each other by welding; The eccentric place of gear (14) is hinged one end of described connecting rod (17) by hinge, and the other end of described connecting rod (17) is hinged with an end of described claw (18), and the end of described claw (18) The other end passes through the guide base (19), the claw (18) is slidingly connected to the guide base (19) through clearance fit, and the guide base (19) is welded on the small cylindrical gear The edge of the shaft mounting body (12); the self-locking device (20) is located between the housing (1) and the bevel pinion (5), and the ratchet (206) of the self-locking device (20) passes through The spline is installed on the pinion bevel gear shaft (6), the base (201) of the self-locking device (20) is fixedly connected with the housing (1) by screws, and the self-locking device (20) The adjusting screw (204) is threadedly connected with the housing (1); the housing (1), the The bevel gear support (2), the bevel gear (3), the bevel gear bearing (4), the cover (8), the flange type connector (9), the The axes of the cylindrical external ring gear (10), the cylindrical external ring gear bearing (11), the small cylindrical gear shaft mounting body (12) and the cylindrical ring type connecting body (13) are on the same straight line; The small bevel gear (5), the small bevel gear shaft (6), the small bevel gear bearing (7), the small cylindrical gear (14), the small cylindrical gear shaft (15), the small There are three sets of cylindrical gear bearings (16), the connecting rod (17), the claws (18), the guide base (19) and the self-locking device (20), and they surround the same bar. straight line distribution. 2. A kind of clamping device for clamping the inner wall of the test piece as claimed in claim 1, characterized in that, the outer casing (1) is a hollow cylindrical structure, and one end surface of the cylindrical body is covered by Removed, the other end surface is provided with three threaded holes equally divided around the axis, and one end of the shell (1) provided with the threaded holes is connected with one end of the cylindrical ring type connecting body (13) by screws; Three circular through-holes I are separated on the side of the cylinder, the axes of the three circular through-holes I are on the same plane I, the plane I is parallel to the two end faces, and the plane I is located One side of the central symmetry plane of the two end faces, and the side close to the removed end face; three threaded through holes are separated on the side of the cylinder, and the axes of the three threaded through holes are on the same On the plane II, and the plane II is located next to the plane I; on the side of the cylinder, there are three circular through holes II, and the centers of the three circular through holes II are on the same plane III , and the plane III is symmetrical to the plane I with respect to the central symmetry plane of the two end faces. 3. A clamping device for clamping the inner wall of a test piece according to claim 2, wherein the self-locking device (20) comprises: a base (201), a spring (202), a support frame (203), adjusting screw (204), ratchet (205), ratchet (206); the base (201) is a cuboid structure, fixed on the inner surface of the housing (1) by screws, the One end of the side of the base (201) is welded with the spring (202), and the other end is welded with the support frame (203); the support frame (203) is a square truss structure, and the support frame (203) The lower end of the bottom surface is welded on the base (201), and the upper bottom end is hinged on the middle side of the pawl (205), and is the side away from the teeth of the pawl (205); The inner side of one end of the tooth of the ratchet (205) is fitted with the adjusting screw (204), and the adjusting screw (204) is fixed and installed together by screw rod, cylinder and round platform in sequence, and the cylinder and the The outside of the round table is glued with a shell made of elastomer material with high resilience, and the screw of the adjusting screw (204) is connected with the threaded through hole of the shell (1) through threads, and the adjusting The shell of the cylinder of the screw rod (204) and the shell of the circular platform are in contact with the inner side of an end away from the teeth of the pawl (205); one end of the spring (202) is welded on the base (201 ), the other end is welded on the other side of the middle of the pawl (205), and is close to the tooth side of the pawl (205); The ratchet (206) is installed, and the ratchet (206) is installed on one end of the pinion bevel gear shaft (6) through a spline, and is close to the end of the pinion bevel gear (5). 4. A kind of clamping device for clamping the inner wall of the test piece as claimed in claim 3, characterized in that, the bevel tooth disc support body (2) is located inside one end of the housing (1), and One end of the housing (1) is the end from which the end face is removed; the bevel gear support body (2) is a flange plate structure, and the inner hollow cylinder is composed of a ring disc 1 and two end faces removed I are connected to each other by welding, and one end of the hollow cylinder I has a stepped circular groove, and the end with the stepped circular groove is the end away from the annular disk I. 5. A kind of clamping device for clamping the inner wall of the test piece as claimed in claim 4, characterized in that, the flange plate type connecting body (9) is a flange plate structure, and the ring plate II and the inner hollow cylinder II are connected to each other by welding, and one end surface of the cylinder II is removed, and the other end surface has a circular hole, and the one end surface with the circular hole is far away from the ring One end face of disc II. 6. A kind of clamping device for clamping the inner wall of the test piece as claimed in claim 5, characterized in that, the mounting body (12) of the small cylindrical gear shaft is a flange plate structure, and the ring plate III and the inner hollow cylinder III with both ends removed are connected to each other by welding. 7. A kind of clamping device for clamping the inner wall of the test piece as claimed in claim 6, characterized in that, the bottom surface of one end of the jaw (18) is an arc-shaped structure, and the jaw (18) One end of the clamp is the end of the clamped specimen. 8. A clamping device for clamping the inner wall of a test piece as claimed in claim 7, wherein one end of the bevel pinion shaft (6) has an inner hexagonal hole, and the bevel pinion One end of the shaft (6) is the end where the bevel pinion gear bearing (7) is installed.