37results about How to "Precise clamping force" patented technology

The invention discloses a system for automatically regulating the clamping force of a motor-driven injection molding machine. The system is characterized in that four draw bars penetrate through a static template, a movable template and a rear template, and the static template is fixed on the draw bar; a five-point toggle mechanism is connected between the movable template and the rear template, and the crosshead thereof penetrates through the rear template and is sleeved outside a ball screw; the ball screw is driven by a spotting motor; the rear template is connected with the four draw bars through four regulating nuts; a bearing is arranged between each regulating nut and the rear template; the peripheries of the regulating nuts are provided with gear teeth; a rack wheel is arranged at the neutral position of the four regulating nuts and is meshed with the gear teeth of the four regulating nuts; the crosshead of the five-point toggle mechanism and the ball screw pass through the center of the rack wheel; the output gear of a mold-adjustment motor is meshed with the rack wheel; and the mold-adjustment motor is connected with an injection molding machine control system. The invention also aims at providing a method for automatically regulating the clamping force of a motor-driven injection molding machine. The invention has the advantages that the mold-adjustment accuracy is high.

A holder is designed to receive a cutting insert intended for parting and grooving operations. The insert is clampable in a seat formed between a blade tongue and a clamping finger which respectively extend from lower and upper front parts of the holder. A gap separates those front parts in order to enable those parts to be forced towards each other by means of a clamping mechanism mounted in the holder. The clamping mechanism comprises a drawbar, a first end portion of which is movable within a bore formed in one of the front parts, and a second end portion of which is fixed in the other front part. The first end portion of the drawbar includes a head having a frusto-conical abutment surface. A tightening screw is threadedly mounted in the same front part as the head and is arranged to contact the abutment surface to displace the drawbar in a direction forcing the clamping finger and the tongue together to clamp the cutting insert in place.

The invention discloses a transplanter for greenhouse vegetable seedlings. The transplanter comprises a mechanical arm (1), a mechanical hand (2) and an automatic feeding system; the automatic feeding system comprises a seedling conveying device (3), a steering device (4), an empty tray recovering device (5), a seedling receiving device (6) and a protective pedal (7), wherein the seedling conveying device (3) is connected with the empty tray recovering device (5) through the steering device (4), the mechanical arm (1) is arranged above the seedling conveying device (3), the mechanical hand (2) is installed on the mechanical arm (1), the seedling receiving device (6) is arranged below the seedling conveying device (3), and the protective pedal (7) is arranged above the seedling receiving device (6). The greenhouse vegetable seedlings can be automatically transplanted through the transplanter, the transplanter is used for automatically conveying and receiving the seedlings, collecting seedling trays and conveying planting floating plates in the transplanting process of the greenhouse vegetable seedlings, the transplanting operation is not limited by manual seedling feeding speed and intensity any more, and the production efficiency of greenhouse vegetables is substantially improved.

A tensioning device for bicycle front and rear wheel assemblies. A skewer assembly with a thumbnut is securable to the wheel assembly with a quick-release assembly. Portions of the skewer assembly are removable from the quick-release assembly by turning the thumbnut a partial turn, such as a quarter of a turn. Removal of the skewer assembly allows the front wheel to be removed. In another embodiment, the skewer assembly is able to be removed by turning the quick-release assembly by a partial turn, such as a quarter of a turn.

A clamping device includes a first clamping arm and a second clamping arm, an arm driving portion for displacing the first clamping arm to a clamping position and a non-clamping position, and a clamping force applying portion for applying a required clamping force to the clamping arm. The arm driving portion has a first driving source for displacing the first clamping arm and a power transmission mechanism. The clamping force applying portion has a pressing member for applying the clamping force to the first clamping arm by applying a rotating force in a clamping direction to the rotary shaft and a second driving source for displacing the pressing member from a non-operating position to an operating position for applying the clamping force.

The invention discloses a metal belt-type stepless transmission target clamping force calculation method based on reserved clamping force. The method comprises the steps that according to formulas, the minimum target clamping force F<pri> of a driving belt wheel and the minimum target clamping force F<sec> of a driven belt wheel are calculated; and then according to the current target speed ratioand the corresponding clamping force ratio, the driven belt wheel target clamping force F<sec_KPKS> corresponding to the driving belt wheel and the driving belt wheel target clamping force F<pri_KPKS>corresponding to the driven belt wheel are calculated.

The invention discloses a large-size round timber processing facility for agriculture and forestry, and relates to the technical field of wood processing. The large-size round timber processing facility for the agriculture and forestry comprises a base, a machine frame, a power assembly, a lifting platform and a locating mechanism. The machine frame and the locating mechanism are installed at thetwo ends of the base correspondingly. The power assembly is installed on the machine frame, cooperates with the locating mechanism and drives a piece of round timber to rotate around the axis of the power assembly. The lifting platform is installed between the machine frame and the locating mechanism and used for achieving feeding and discharging operation of the round timber. By the adoption of the large-size round timber processing facility for the agriculture and forestry, the surface processing treatment work of the large-size round timber is achieved, namely, a driving motor drives the round timber to rotate, the locating mechanism cooperates with a driving disc to achieve the axial locating of the round timber, the clamping and locating operation of one end of the round timber is achieved in the mode that a supporting frame is fixed, and an inner sleeve moves, the process can be achieved under the condition that only the hydraulic oil needs to be fed into the facility, the locating process is simplified, the manpower is saved, the clamping force is more accurate, and the effect of avoiding the round timber rotation situation which happens due to the fact that the torque is excessively high is also achieved.

The invention discloses a high-precision automatic workpiece clamping manipulator system. The system comprises an adjustable chuck, an extension arm, a support arm, a track wire groove, a rotary support column, an alarm lamp, a base and a control box; the adjustable chuck is fixed at the lower end of the right side of the extension arm through a bolt; the outer wall of the extension arm is mechanically connected with a guide rail in the support arm; the track wire groove is horizontally fixed at the upper end of the outer wall of the support arm; the rotary support column is mounted on the right side of the alarm lamp, and is movably connected with the top of the base; the control box is horizontally fixed on the inner wall of the base; and the adjustable chuck is electrically connected with elements in the control box through the chuck. An adjustable clamping arm adjusts the clamping force more precisely, so that an improved high-precision automatic workpiece clamping manipulator canfreely adjust the clamping force, the workpiece clamping safety can be preferably guaranteed, the clamping speed is high, the workpiece damage degree is lower, and the precision cannot be influenced.

The invention relates to an outer circle turning clamp of a thin wall bearing ring. The outer circle turning clamp is characterized by comprising a disc-shaped clamp body, wherein the front end of the clamp body is provided with a positioning boss for positioning an inner hole of one end of the thin wall bearing ring, the front part of a positioning boss is provided with a slide guide part, a pressing ring glidingly sleeves the slide guide part, and is provided with an outer conical surface, an expansion ring sleeves the exterior of the pressing ring, and is provided with an inner conical hole which is matched with the outer conical surface of the pressing ring, at least two limiting screws penetrate through holes of the pressing ring and are connected with the clamp body, a plurality of bolt holes are respectively and uniformly formed in the clamp body and the pressing ring and are connected with a main shaft of a lathe, and a pressing gap is formed between the inner end surface of the pressing ring and the front end surface of the clamp body. The outer circle turning clamp has the advantages that the structure is simple, the clamping is convenient and rapid, the direction of clamping force is coincided with the positioning point of the bearing ring, the positioning is accurate, the clamping force is stable, the error of processing size is reduced, the turning qualified rate of the thin wall bearing ring is improved, the processing efficiency is improved, and the production cost is reduced.

The invention discloses a specimen holder of a tube or a bar for a tension test. The specimen holder comprises a tension handle, a locking part, a holding seat and a holder body, wherein the holder body comprises a cylinder body and a circular truncated cone body which are integrally formed; the maximum external diameter of the circular truncated cone body is greater than the external diameter of the cylinder body; the whole circular truncated cone body is provided with at least two grooves along the axial direction, and the two grooves are used for segmenting the circular truncated cone body into holding blocks; a holding part for holding a test specimen is arranged on the inner surface of each clamping block; the holding seat sleeves the outside of the holder body and is connected with the holder body in a matching way; the holding seat is provided with a first conical surface matched with the circular truncated cone body; the front end of the locking part is connected with the holding seat through a spiral structure; the tension handle is connected with the rear end of the locking part. The specimen holder disclosed by the invention is small in size, convenient in disassembly and assembly and uniform and reliable in holding force; the specimen holder realizes automatic centering in a clamping process, is uniform, quick and reliable in clamping, and is particularly suitable for being used in a high-low temperature environmental cabinet with compact structure and small space.

A device for generating a massage stream in a sanitary tub has an accommodation device that can be attached to an opening in the tub body of the sanitary tub, for accommodating an electric motor having a drive shaft, a propeller having a hub attached to the drive shaft and vanes arranged radially about the hub. There is a rosette arranged on the accommodation device, positioned within the sanitary tub, having edge-side inflow openings, as well as a central outlet opening. The propeller draws water located in the sanitary tub in through the inflow openings, and subsequently transports it back into the sanitary tub, through a guide element arranged in the outlet opening, which can be pivoted relative to the hub axis. The guide element is configured as a guide vane ring and has a ring-shaped bearing shell at the outer end of the guide vanes. The shell moves between a glide surface of the accommodation device that is configured as a sphere surface segment, and a concave contact surface of the rosette.

A holder is designed to receive a cutting insert intended for parting and grooving operations. The insert is clampable in a seat formed between a blade tongue and a clamping finger which respectively extend from lower and upper front parts of the holder. A gap separates those front parts in order to enable those parts to be forced towards each other by means of a clamping mechanism mounted in the holder. The clamping mechanism comprises a drawbar, a first end portion of which is movable within a bore formed in one of the front parts, and a second end portion of which is fixed in the other front part. The first end portion of the drawbar includes a head having a frusto-conical abutment surface. A tightening screw is threadedly mounted in the same front part as the head and is arranged to contact the abutment surface to displace the drawbar in a direction forcing the clamping finger and the tongue together to clamp the cutting insert in place.

The invention relates to a combination driving-type compound die mechanism of a full electric injection molding machine, belonging to the field of compound die mechanism, comprising an external synchronous belt, an adjusting screw nut, a conventional motor, a support plate, a pull rod, a toggle rod mechanism, a movable platen, a mould, a fixed die plate, a support angle, a screw thread crosshead, a servo motor, a screw-threaded draw bar and an internal synchronous belt. The compound die mechanism adopts combination drive principle to design, and the power source is the servo motor and the conventional motor. Output motion of the servo motor, linear motion of the support plate and output motion generated by the conventional motor, linear motion of the supporting angle are synthesized through a toggle rod mechanism of two degrees of freedom to generate programmable output motion. The system combines the advantages of a traditional mechanical system and a total servo electromechanical system, can realize flexible output motion, has the characteristics of high loading capacity, rapid operational speed and low cost.

The invention discloses a clamping device and method for controlling the clamping force on a workpiece through a linear motor. The clamping device comprises a base, the linear motor, a telescopic rod, a control unit, a transmission mechanism and a clamping jaw mechanism; the clamping jaw mechanism comprises friction force sensing jaws and mechanical clamping jaws, and friction force sensors are arranged on the contact faces of the friction force sensing jaws and the workpiece; the linear motor is connected with the telescopic rod; and the control unit sends an electric signal, the linear motor drives the telescopic rod to move, and then the transmission mechanism is driven to control opening and closing of the clamping jaw mechanism. According to the clamping device, the friction force sensing jaws are in contact with the workpiece, so that the friction force sensors sense vertical friction force generated when the workpiece is in contact with the friction force sensing jaws; and the friction force sensors process and judge the vertical friction force and feeds back the vertical friction force to a CPU, the CPU controls a driving signal of the linear motor and enables the clamping device to provide clamping force according to the friction force generated by relative sliding between the contact faces of the mechanical clamping jaws and the workpiece, and accurate control over the clamping force is achieved.

The invention relates to a bearing unit, preferably, a wheel bearing unit (1) for a motor vehicle, comprising a hub (2) provided with a wheel-sided securing flange (11), whereon an angular contact anti-friction bearing (6), which comprises at least one inner ring (7) and an outer ring (8), is arranged. In order to produce the bearing unit (1) and to operate it in an economical manner, and also to prevent, for example, deformation and tensions characteristic of known roller riveting units, the securing flange (3) is connected in a material fit to the flange ring (11) in relation to the end (10) of the hub (2), which clamps at least the inner ring (7) to the hub (2).; The invention also relates to a method for producing a bearing unit (1), preferably, a wheel bearing unit for a motor vehicle, comprising a hub (2) which is provided with a wheel-sided securing flange (3) whereon an angular contact anti-friction bearing (6) comprising at least one inner ring (7) and an outer ring (8), is arranged, by means of a device (13) which exerts a clamping force (F) on the bearing unit (1).

The invention relates to an engine cylinder head overturning device, which includes a mounting frame, and two opposite clamping mechanisms that can precisely control the length for clamping the engine cylinder head are slidingly arranged inside the mounting frame. The side of the clamping mechanism is provided with an overturning mechanism for rotating the clamping mechanism, which can precisely control the overturning angle. The present invention installs a worm at the front end of the first motor, drives the main rod to move through the rotation of the worm, realizes the precise control of the moving length of the main rod, makes the clamping force of the main rod to the engine cylinder head more accurate, and avoids the Too much or too little movement of the main rod will cause unnecessary damage to the engine cylinder head and insufficient clamping force. The present invention also sets two sets of gear sets with different numbers of teeth, and realizes the fineness of different rotation angles through different gears. The control is used to deal with processing devices in different directions and different needs, so as to facilitate the repair and processing of corresponding processing devices.

An electronic part clamp comprises a bottom plate and two stand columns fixedly connected to the left side and the right side of the upper portion of the bottom plate, and further comprises a plurality of pairs of horizontal electric push rods oppositely arranged in the longitudinal direction. The rod ends of each pair of horizontal push rods are oppositely arranged and fixedly connected with clamping plates, and bases at the rod ends of each pair of horizontal push rods are fixedly connected with the inner side faces of the two stand columns respectively. A pressure sensor is installed on theinner side face of one of the two clamping plates on each pair of horizontal push rods in an attached mode, and each pressure sensor is correspondingly provided with a pressure display instrument, wherein the pressure display instruments are installed on the stand columns. The clamp can effectively fix an electronic product part and can prevent the electronic product part from being damaged by clamping.

The invention discloses a metal belt-type stepless transmission target clamping force calculation method based on reserved clamping force. The method comprises the steps that according to formulas, the minimum target clamping force F<pri> of a driving belt wheel and the minimum target clamping force F<sec> of a driven belt wheel are calculated; and then according to the current target speed ratioand the corresponding clamping force ratio, the driven belt wheel target clamping force F<sec_KPKS> corresponding to the driving belt wheel and the driving belt wheel target clamping force F<pri_KPKS>corresponding to the driven belt wheel are calculated.

The utility model discloses a kind of self-adapting assembly component clamp device, comprising: mounting bracket;Fixed chuck, fixed on the mounting bracket;Movable chuck, for cooperating with the fixed chuck and clamping workpiece;Outer tube, set on the mounting bracket;Slide bar, slidingly set in the outer tube, the slide bar moves under the direction of first gas pressure towards the fixed chuck;The driving block and the movable chuck between there is mutually matched slope;Cylinder, for driving the driving block moves after the slide bar is locked and cooperates, to drive the movable chuck moves towards the direction of the fixed chuck by the cooperation of the slope.The technical scheme not only improves the compatibility of fixture to diversified products, and through accurate secondary clamping, the clamping accuracy and reliability in assembly process are guaranteed, so as to improve production efficiency and product quality, effectively solve the problem proposed in background art.

The invention discloses a positioning mechanism for agricultural and forestry large-dimension round timber processing, and relates to the technical field of wood processing. The positioning mechanismcomprises a bearing frame, an outer sleeve, an inner sleeve, a liquid inlet tube, a piston, an ejector pin and a drive mechanism. Clamping and positioning for one end of wound timber is realized through a way of fixing the bearing frame and moving the inner sleeve; compared with a conventional tail base positioning way, the positioning mechanism does not need to manually shake a rocker handle to realize movement of the tail base, and can realize positioning by only needing to introducing in hydraulic oil, so that a positioning process is simplified, and labor power is saved; meanwhile, a top plate is firstly in contact with the round timber, the round timber is locked by the ejector pin, and is finally pressurized until pressure achieves a set value, so that clamping and positioning of theround timber are realized, and clamping force is more precise; and meanwhile, a rotation condition, caused by too great torque, of the round timber is further prevented.

The invention discloses a novel tiebar on an injection molding machine. The tiebar comprises tiebar bodies, limiting rings are fixed to the tops of the left ends of the tiebar bodies, permanent magnets are arranged at the left ends of the limiting rings, fixing grooves are formed in the bottoms of the ends, away from the limiting rings, of the tiebar bodies, the left end faces of the tiebar bodies are in threaded connection with fixing bolts, mold adjusting plates are arranged at the ends, close to the limiting rings, of the tiebar bodies, movable mold plates are arranged on the sides, away from the limiting rings, of the mold adjusting plates, fixed mold plates are arranged on one sides of the movable mold plates, fixing assemblies are arranged on the right sides of the fixed mold plates, positioning assemblies are arranged on the sides, close to the limiting rings, of the mold adjusting plates, the right end faces of the fixing bolts are provided with clamping grooves, and fixing and locking assemblies are arranged at the tops of the fixing bolts. According to the novel tiebar on the injection molding machine, by arranging the fixing and locking assemblies, the situation that the fixing bolts are loosened after long-time use can be prevented; and through positioning holes, a touch switch and an indicator lamp, whether the tie bar bodies are fixed to the mold adjusting plates or not can be strikingly displayed.

The invention discloses a transplanter for greenhouse vegetable seedlings. The transplanter comprises a mechanical arm (1), a mechanical hand (2) and an automatic feeding system; the automatic feeding system comprises a seedling conveying device (3), a steering device (4), an empty tray recovering device (5), a seedling receiving device (6) and a protective pedal (7), wherein the seedling conveying device (3) is connected with the empty tray recovering device (5) through the steering device (4), the mechanical arm (1) is arranged above the seedling conveying device (3), the mechanical hand (2) is installed on the mechanical arm (1), the seedling receiving device (6) is arranged below the seedling conveying device (3), and the protective pedal (7) is arranged above the seedling receiving device (6). The greenhouse vegetable seedlings can be automatically transplanted through the transplanter, the transplanter is used for automatically conveying and receiving the seedlings, collecting seedling trays and conveying planting floating plates in the transplanting process of the greenhouse vegetable seedlings, the transplanting operation is not limited by manual seedling feeding speed and intensity any more, and the production efficiency of greenhouse vegetables is substantially improved.

The invention discloses a system for automatically regulating the clamping force of a motor-driven injection molding machine. The system is characterized in that four draw bars penetrate through a static template, a movable template and a rear template, and the static template is fixed on the draw bar; a five-point toggle mechanism is connected between the movable template and the rear template, and the crosshead thereof penetrates through the rear template and is sleeved outside a ball screw; the ball screw is driven by a spotting motor; the rear template is connected with the four draw bars through four regulating nuts; a bearing is arranged between each regulating nut and the rear template; the peripheries of the regulating nuts are provided with gear teeth; a rack wheel is arranged at the neutral position of the four regulating nuts and is meshed with the gear teeth of the four regulating nuts; the crosshead of the five-point toggle mechanism and the ball screw pass through the center of the rack wheel; the output gear of a mold-adjustment motor is meshed with the rack wheel; and the mold-adjustment motor is connected with an injection molding machine control system. The invention also aims at providing a method for automatically regulating the clamping force of a motor-driven injection molding machine. The invention has the advantages that the mold-adjustment accuracy is high.

The invention discloses a stacking and storing device for annular forgings, and mainly relates to the field of workpiece storage. Comprising a bottom plate, a plurality of stand columns are arranged on the bottom plate, a plurality of storage bases rotating in the transverse direction are distributed on the stand columns in an array mode, a blocking column is movably connected to one side of each stand column, supporting blocks are slidably connected to the storage bases in the vertical direction, clamping rods are symmetrically and rotationally connected to the two sides of the storage bases, and the bottoms of the supporting blocks make contact with the bottom ends of the two clamping rods at the same time; a clamping plate is arranged at the top end of the clamping rod, a reset spring is arranged between the clamping rod and the storage base, a limiting rod is arranged on the storage base, a limiting groove is formed in the supporting block, a plurality of pressing blocks are arranged on the blocking column, when the blocking column moves downwards, the pressing blocks drive the limiting rod to enter the limiting groove, and a pressing rod is arranged on the stand column. The annular forge piece storage and transportation device has the beneficial effects that the technical problem that the firmness and safety are poor when annular forge pieces are stored and transported can be solved, shaking of the annular forge pieces in the transportation process is avoided, and the transportation stability and safety are improved.

The invention discloses a mechanical arm for machining and welding automobile parts. The mechanical arm comprises a base; one end of the big arm is rotationally assembled on the upper end face of the base; the small arm is rotationally assembled at the other end of the large arm; one end of the wrist joint arm is rotationally connected to the end part of the small arm, and the other end of the wrist joint arm is rotationally connected with a connecting flange; the welding gun unit is mounted on the lower end face of the connecting flange; the edge pressing unit is assembled on the welding gun unit; the mechanical arm can continuously complete the action of pressing, bending and welding in one-time clamping and positioning, the time for workpiece transferring and repeated positioning is greatly shortened, and the production takt time and the overall machining efficiency are remarkably improved; and accurate and reliable clamping force can be applied to an area adjacent to a welding point, and micro-motion, warping and deformation of a thin plate part in the welding process are effectively restrained.

The invention provides a clamping device for off-line detection of a motor gearbox of a new energy automobile, and relates to the technical field of off-line detection of motor gearboxes. The clamping device for off-line detection of the motor gearbox of the new energy automobile comprises a mounting plate, and a fixed clamping plate and a movable clamping plate which are arranged in a matched mode are arranged above the mounting plate; the fixed clamping plate is fixedly connected with the upper surface of the mounting plate, and the movable clamping plate is slidably connected with the upper surface of the mounting plate; the opposite faces of the fixed clamping plate and the movable clamping plate are fixedly connected with an output shaft positioning sleeve used for positioning an output shaft of the gearbox, and the opposite faces of the fixed clamping plate and the movable clamping plate are rotationally connected with a rotating ring through a plane bearing. And the opposite surfaces of the movable clamping plate and the fixed clamping plate are rotationally connected with a mounting disc which is concentric with the rotating ring. The clamping device for off-line detection of the motor gearbox of the new energy automobile has the advantage of being small in use limitation.

The invention discloses a positioning mechanism for processing large-size logs used in agriculture and forestry, which relates to the technical field of wood processing and includes a support bracket, an outer sleeve, an inner sleeve, a liquid inlet pipe, a piston, a thimble and a driving mechanism. The support bracket is fixed, and the inner sleeve moves to realize the clamping and positioning of one end of the log. Compared with the traditional tailstock positioning method, there is no need to manually shake the handle to realize the movement of the tailstock, only need to pass in hydraulic oil It can be realized, which simplifies the positioning process and saves manpower. At the same time, the top plate first contacts the log, then locks it with the thimble, and finally pressurizes until the pressure reaches the set value to realize the clamping and positioning of the log. The clamping force is more precise, and it also prevents the log from turning due to excessive torque.

This application provides an automatic rotary collet mechanism, including a collet chuck for clamping a workpiece to be processed and a collet chuck drive device for driving the collet chuck to move. The collet chuck and a power transmission shaft are disposed within the internal space formed by the rotating shaft. The power transmission shaft is driven to perform axial reciprocating motion by the pressure generated by the fluid in the fluid channel. One end of the power transmission shaft is provided with a pull lug, and one end of the collet chuck is provided with a limiting groove that matches the shape of the pull lug. A closed fluid channel is formed inside the rotating shaft. The collet chuck, driven by the pull lug, performs axial reciprocating motion along the rotating shaft while simultaneously clamping or retracting radially along the rotating shaft. The automatic rotary collet mechanism provided by this application improves clamping stability and helps to improve the processing quality of the workpiece clamped therein.

The invention discloses a specimen holder of a tube or a bar for a tension test. The specimen holder comprises a tension handle, a locking part, a holding seat and a holder body, wherein the holder body comprises a cylinder body and a circular truncated cone body which are integrally formed; the maximum external diameter of the circular truncated cone body is greater than the external diameter of the cylinder body; the whole circular truncated cone body is provided with at least two grooves along the axial direction, and the two grooves are used for segmenting the circular truncated cone body into holding blocks; a holding part for holding a test specimen is arranged on the inner surface of each clamping block; the holding seat sleeves the outside of the holder body and is connected with the holder body in a matching way; the holding seat is provided with a first conical surface matched with the circular truncated cone body; the front end of the locking part is connected with the holding seat through a spiral structure; the tension handle is connected with the rear end of the locking part. The specimen holder disclosed by the invention is small in size, convenient in disassembly and assembly and uniform and reliable in holding force; the specimen holder realizes automatic centering in a clamping process, is uniform, quick and reliable in clamping, and is particularly suitable for being used in a high-low temperature environmental cabinet with compact structure and small space.