CN107584492B - Self-adaptive pneumatic gripper for casting robot - Google Patents

Abstract

The invention discloses a self-adaptive pneumatic gripper for a casting robot, which comprises a connecting support, a main support, an upper clamping device, a lower clamping device and a self-adaptive adjusting connecting rod assembly. The connecting support can be arranged on the tail end flange of the hand of the casting robot, each upper clamping jaw and each lower clamping jaw are independently connected and controlled through the corresponding upper clamping cylinder and the corresponding lower clamping cylinder, the radial distance and the radial angle of the upper clamping jaw and the radial angle of the lower clamping jaw are adjusted, the outer surface of the gripped workpiece can be automatically adapted, and the effective laminating type clamping of the workpiece is realized. The invention can meet the grabbing requirements of the casting robot on workpieces such as pouring cups, sand cores and the like, can simultaneously meet the self-adaptive grabbing operation requirements of cylindrical workpieces and round table workpieces, has the advantages of simple structure, light weight, good stability, high safety, strong self-adaptability, simple and convenient operation and maintenance and the like, and reduces the labor intensity and the production cost of operators.

Description

Adaptive pneumatic gripper for foundry robots

Technical field

The invention belongs to the technical field of industrial robot equipment, and particularly relates to an adaptive pneumatic gripper for casting robots.

Background technique

The high degree of flexibility of industrial robots can meet various special requirements in modern green casting production. The use of robots in foundry production can not only liberate operators from heavy and monotonous manual labor, save labor, but also improve casting production efficiency. Manufacturing precision and quality, an important means to realize the mechanization, automation and civilization of casting production. Foundry robots can not only be used for handling and transmitting castings in die casting and precision casting production, but can also be used in sand casting processes such as shaping, core making, core setting, pouring, cleaning and inspection. When a casting robot performs operations such as coring, core grouping, core setting, and transportation, in addition to the robot body, the robot gripper as an end effector becomes an important key equipment. In the production of medium and large castings, the sizes and weights of sprue cups, sand core components and castings are relatively large, making it difficult and demanding to perform coring, core grouping, core setting, pouring and handling operations. At present, most existing robot grippers are of the external clamping type, whose main feature is to clamp the workpiece from the outside, and the size of the gripper is relatively large. Especially for hollow workpieces such as sprue cups, there is no suitable robot gripper when performing grasping tasks. In particular, there is a lack of adaptive robot grippers that can grasp workpieces with both cylindrical and truncated cone shapes.

In view of the problems existing in casting grabbing, existing patent documents have also proposed some solutions. The Chinese patent application number 201621329359.4 discloses a small internally supported start-up manipulator, which includes a slider, a guide sleeve, a base and evenly arranged connecting rods and claws. The telescopic cylinder of a small cylinder is used to drive the slider and connecting rod up and down. Move and drive the claws to tighten and relax, but only point contact can be achieved between the three claws and the workpiece. The contact area between the claws and the inner surface of the workpiece is too small, which can easily cause damage to the clamping point of the workpiece and is not suitable for grabbing. Sprue cups or hollow sand core components or softer castings. The Chinese patent application number 201520758016.9 discloses a ring-shaped object grabbing manipulator, which includes a grabbing mechanism, a grabbing moving mechanism and a grabbing driving mechanism. The grabbing driving mechanism drives multiple grabbing claws to make the multiple grabbing claws The opening end rotates outward at the same time and expands within the inner ring of the annular object to grasp the annular object. There is a rigid contact between the grasping claw and the workpiece. It is mainly suitable for grasping wire reels and tires, but not suitable for gates. Grabbing of workpieces such as cups and sand cores.

Contents of the invention

The purpose of the present invention is to address the shortcomings of the existing technology and provide an adaptive pneumatic gripper for a casting robot that can be used by the casting robot to perform coring, core grouping, core setting and transportation during the casting and molding process of medium and large castings. The workpiece is grasped during operation, which can meet the adaptive grasping operation requirements of both cylindrical and truncated workpieces, improve the operating efficiency, stability and safety of casting production, reduce labor intensity and production cost, and can overcome the existing technology Defects.

The technical problems to be solved by the present invention are achieved by adopting the following technical solutions.

An adaptive pneumatic gripper for casting robots includes a connecting support, a main bracket, an upper clamping device, a lower clamping device and an adaptive adjusting connecting rod assembly. Wherein, the connecting support includes a connecting flange and a connecting support plate. The connecting flange is provided with a mounting hole connected to the hand flange of the casting robot. The inner end of the connecting support plate is connected to the hand flange of the casting robot. The connecting flange is fixedly connected, and the outer end of the connecting support plate is fixedly connected to the upper end of the main bracket. The main bracket is located below the connecting support and is used to support and install the upper clamping device, the lower clamping device and the adaptive adjustment link assembly. The upper clamping device and the lower clamping device are fixedly installed on the upper and lower ends of the main bracket respectively, and are used to clamp the workpiece to be grabbed; the upper clamping device and the lower clamping device are adjusted through an adaptive connecting rod. components are connected. The adaptive adjustment link assembly is installed at the inner middle part of the main bracket and is used to connect the upper clamping device and the lower clamping device and assist in adjusting the postures of the upper clamping device and the lower clamping device; The upper end of the adjusting link assembly is connected to the lower end of the upper clamping device through a hinge, and the lower end of the adaptive adjusting link assembly is connected to the upper end of the lower clamping device through a hinge. The upper clamping cylinder and the lower clamping cylinder adopt double-acting cylinders. On the premise of ensuring that the same clamping force is generated on the grabbed workpiece, they also have the functions of buffering and vibration reduction to avoid damage to the grabbed workpiece. Causes damage to the surface. The upper clamping cylinder and the lower clamping cylinder are connected to the electromagnetic reversing valve, safety valve and air source through pipelines.

The main bracket includes a vertical support plate, an upper enclosure plate and a lower enclosure plate. Wherein, the vertical support plate is used to fix and install the upper clamping device, the lower clamping device and the adaptive adjustment link assembly, and the upper and lower enclosure plates are used to connect and fix the vertical support plates. The upper enclosure plate is located at the upper end of the vertical support plate and is fixedly connected to the vertical support plate. The lower enclosure plate is located at the lower end of the vertical support plate and is fixedly connected to the vertical support plate through screws. The upper enclosure plate is connected to the vertical support plate. The outer ends of the connecting support plates in the connecting support are fixed with screws.

The upper clamping device includes an upper clamping cylinder, an upper clamping jaw and an upper tension spring. Among them, the cylinder part of the upper clamping cylinder is installed outside the upper end of the vertical support plate, and the front end of the piston rod of the upper clamping cylinder is located inside the upper end of the vertical support plate, which is used to provide power for the clamping action of the upper clamping jaw. ; The upper clamping jaw is located at the inner upper end of the main bracket and is used to clamp and grab the workpiece; and the front end of the piston rod of the upper clamping cylinder is connected to the middle part of the upper clamping jaw through a hinge; the upper tension spring is located at The inner side of the upper end of the vertical support plate, and located above the piston rod of the upper clamping cylinder, is used to provide power for the upper clamping jaw to autonomously return to the initial state after completing the grasping operation. The inner end of the upper tension spring is hooked On the upper clamping jaw, the outer end of the upper tension spring is hooked on the vertical support plate.

The lower clamping device includes a lower clamping cylinder, a lower clamping jaw and a lower tension spring. Among them, the cylinder part of the lower clamping cylinder is installed outside the lower end of the vertical support plate, and the front end of the piston rod of the lower clamping cylinder is located inside the lower end of the vertical support plate, which is used to provide power for the clamping action of the lower clamping jaw. ; The lower clamping jaw is located at the inner lower end of the main bracket and is used to clamp and grab the workpiece; and the front end of the piston rod of the lower clamping cylinder is connected to the middle part of the lower clamping jaw through a hinge; the lower tension spring is located vertically The inner side of the lower end of the support plate is located below the piston rod of the lower clamping cylinder. It is used to provide power for the lower clamping claw to automatically return to the initial state after completing the grasping operation. The inner end of the lower tension spring is hooked on the lower clamp. On the claw, the outer end of the upper tension spring is hooked on the vertical support plate.

The adaptive adjustment link assembly includes an upper link, a lower link and a middle tension spring. Wherein, the upper end of the upper connecting rod and the lower end of the upper clamping jaw are connected through a hinge, the lower end of the lower connecting rod and the upper end of the lower clamping jaw are connected through a hinge, and the upper connecting rod and the lower connecting rod Connected by hinges; the middle tension spring is used to provide power for the upper clamping jaw, lower clamping jaw, upper connecting rod, and lower connecting rod to autonomously return to the initial state. The inner end of the middle tension spring is hooked on The lower end of the connecting rod and the outer end of the middle tension spring are hooked on the vertical support plate.

The upper clamping jaw includes an upper rigid support plate and an upper anti-slip layer. The upper anti-slip layer is fixed on the inner side of the upper rigid support plate through screws and adhesives, and is provided on the surface of the upper anti-slip layer. There are transverse anti-slip ribs, which can increase the friction between the upper anti-slip layer and the workpiece to prevent the workpiece from slipping during the grabbing process; the lower clamping jaw includes a lower rigid support plate and a lower anti-slip layer, and the lower anti-slip layer The layer is fixed on the inner side of the lower rigid support plate through screws and adhesives, and transverse anti-slip ribs are provided on the surface of the lower anti-slip layer, which can increase the friction between the lower anti-slip layer and the workpiece and avoid the workpiece Slips out during grasping. The upper rigid support plate and the lower rigid support plate are made of aluminum alloy materials, which can reduce the weight of the upper rigid support plate and the lower rigid support plate themselves; the upper anti-skid layer and the lower anti-skid layer are made of polyester PVC made of fiber cloth and polyvinyl chloride glue or wear-resistant rubber made of natural rubber and reinforced fibers ensure that when the present invention performs the task of grabbing the workpiece, there is sufficient space between the upper clamping jaw, the lower clamping jaw and the workpiece. Friction.

The number of the upper clamping device and the lower clamping device is 3-6, which can ensure sufficient support and clamping points for the grabbed workpiece; the upper clamping device and the lower clamping device in each group The clamping jaws and lower clamping jaws are independently driven and controlled by the corresponding upper and lower clamping cylinders, which can realize adaptive adjustment and effective clamping of the outer surface of the grabbed workpiece, and can also realize cylindrical workpieces. It can grasp the truncated cone-shaped workpiece.

When using, first determine the driving mode of the upper clamping cylinder and the lower clamping cylinder according to the shape of the object to be grasped. When the workpiece to be grasped is a truncated cone, the upper clamping cylinder and the lower clamping cylinder adopt an asynchronous isobaric drive mode to drive the upper and lower clamping jaws to clamp the workpiece to be grasped from the outside; when the workpiece to be grasped is When it is a cylinder, the upper clamping cylinder and the lower clamping cylinder adopt a synchronous isobaric drive method to drive the upper and lower clamping jaws to clamp the grabbed workpiece from the outside. After the operation is completed, it can automatically return to the initial state under the action of the upper tension spring, lower tension spring and middle tension spring.

When performing work tasks, a binocular vision system needs to be installed at the end of the hand of the casting robot to collect the situation of the grabbed workpiece being placed on site and to identify, judge and make decisions about the shape, size and position of the grabbed workpiece.

The beneficial effects of the present invention are: compared with the existing technology, the present invention can be installed on the end flange of the casting robot hand, and each upper clamping jaw and lower clamping jaw pass through the corresponding upper clamping cylinder and lower clamping cylinder. The cylinder is independently connected and controlled, making it easy to adjust the radial distance and angle of the upper and lower clamping jaws. It can automatically adapt to the outer surface of the workpiece to be grabbed, and can achieve effective close-fitting clamping of the workpiece. The invention can be used for the casting robot to place and remove sprue cups when performing pouring tasks, as well as to perform casting operations such as coring, core grouping, core setting and transportation, and can satisfy the casting robot's requirements for workpieces such as sprue cups and sand cores. The grabbing requirements can meet the requirements of adaptive grabbing operations for both cylindrical and truncated cone types of workpieces. With the support of the binocular vision system, it can also automatically collect images of workpieces and automatically complete the identification and grabbing tasks of workpieces. The invention also has the advantages of simple structure, light weight, good stability, high safety, strong adaptability, easy operation and maintenance, etc., reduces the labor intensity and production cost of operators, and can overcome the defects of the existing technology.

Description of the drawings

Figure 1 is a schematic diagram of the overall structure of the present invention;

Figure 2 is a schematic structural diagram of the connecting flange of the present invention;

Figure 3 is a schematic diagram of the connection relationship between the upper clamping device, the lower clamping device and the adaptive adjustment link assembly of the present invention;

Figure 4 is a schematic diagram of the working state of the present invention when grabbing workpieces.

Detailed ways

In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention will be further elaborated below with reference to specific embodiments and illustrations.

As shown in Figures 1, 2, 3 and 4, an adaptive pneumatic gripper for casting robots includes a connecting support 1, a main bracket 2, an upper clamping device 3, a lower clamping device 4 and an adaptive Adjust linkage assembly 5. Among them, the connecting support 1 includes a connecting flange 11 and a connecting support plate 12. The connecting flange 11 is provided with a mounting hole 111 connected to the hand flange of the casting robot. The inner end of the plate 12 is fixedly connected to the connecting flange 11 , and the outer end of the connecting support plate 12 is fixedly connected to the upper end of the main bracket 2 . The main bracket 2 is located below the connecting support 1 and is used to support and install the upper clamping device 3, the lower clamping device 4 and the adaptive adjustment link assembly 5. The upper clamping device 3 and the lower clamping device 4 are fixedly installed on the upper and lower ends of the main bracket 2 respectively, and are used to clamp the grabbed workpiece 6; the upper clamping device 3 and the lower clamping device 4 They are connected through adaptive adjustment link assembly 5. The adaptive adjustment link assembly 5 is installed at the inner middle part of the main bracket 2 and is used to connect the upper clamping device 3 and the lower clamping device 4 and assist in adjusting the postures of the upper clamping device 3 and the lower clamping device 4. ; The upper end of the adaptive adjustment link assembly 5 is connected to the lower end of the upper clamping device 3 through a hinge, and the lower end of the adaptive adjustment link assembly 5 is connected to the upper end of the lower clamping device 4 through a hinge. .

As shown in Figures 1, 3 and 4, the main bracket 2 includes a vertical support plate 21, an upper enclosure 22 and a lower enclosure 23. Among them, the vertical support plate 21 is used to fix and install the upper clamping device 3, the lower clamping device 4 and the adaptive adjustment link assembly 5, and the upper enclosure plate 22 and the lower enclosure plate 23 are used to connect and install Fix the vertical support plate 21. The upper enclosure plate 22 is located at the upper end of the vertical support plate 21 and is fixedly connected to the vertical support plate 21. The lower enclosure plate 23 is located at the lower end of the vertical support plate 21 and is fixedly connected to the vertical support plate 21 through screws. The above-mentioned upper enclosure plate 22 is fixedly connected to the outer end of the connecting support plate 12 in the connecting support 1 by screws.

As shown in Figures 1, 3 and 4, the upper clamping device 3 includes an upper clamping cylinder 31, an upper clamping claw 32 and an upper tension spring 33. Among them, the cylinder part of the upper clamping cylinder 31 is installed outside the upper end of the vertical support plate 21, and the front end of the piston rod of the upper clamping cylinder 31 is located inside the upper end of the vertical support plate 21, and is used for the upper clamping claw 32. The clamping action provides power; the upper clamping jaw 32 is located at the inner upper end of the main bracket 2 for clamping and grabbing the workpiece 6; and the front end of the piston rod of the upper clamping cylinder 31 and the middle part of the upper clamping jaw 32 are hinged connected; the upper tension spring 33 is located inside the upper end of the vertical support plate 21 and above the piston rod of the upper clamping cylinder 31, and is used for the upper clamping jaw 32 to automatically return to the initial state after completing the grabbing operation. To provide power, spring hanging rings are provided on the upper end of the inner surface of the vertical support plate 21 and the upper end of the upper clamping claw 32, and the inner end of the upper tension spring 33 is hooked on the upper clamping claw 32. The outer end of the upper tension spring 33 is hooked on the vertical support plate 21. The lower clamping device 4 includes a lower clamping cylinder 41, a lower clamping claw 42 and a lower tension spring 43. Among them, the cylinder part of the lower clamping cylinder 41 is installed outside the lower end of the vertical support plate 21, and the front end of the piston rod of the lower clamping cylinder 41 is located inside the lower end of the vertical support plate 21, and is used for the lower clamping jaw 42. The clamping action provides power; the lower clamping jaw 42 is located at the inner lower end of the main bracket 2 for clamping and grabbing the workpiece 6; and the front end of the piston rod of the lower clamping cylinder 41 and the middle part of the lower clamping jaw 42 are hinged connected; the lower tension spring 43 is located inside the lower end of the vertical support plate 21 and is located below the piston rod of the lower clamping cylinder 41, which is used to provide the lower clamping jaw 42 with the ability to autonomously return to the initial state after completing the grabbing operation. Power, the lower end of the inner side of the vertical support plate 21 and the lower end of the lower clamping claw 42 are provided with spring hanging rings, the inner end of the lower tension spring 43 is hooked on the lower clamping claw 42, and the upper pull-up The outer end of the spring 43 is hooked on the vertical support plate 21 . The upper clamping cylinder 31 and the lower clamping cylinder 41 are double-acting cylinders. On the premise of ensuring sufficient and equal clamping force on the grabbed workpiece 6, they also have the functions of buffering and vibration reduction to avoid damage to the workpiece 6. The surface of the grabbed workpiece 6 is damaged. The upper clamping cylinder 31 and the lower clamping cylinder 41 are connected to the electromagnetic reversing valve, safety valve and air source through pipelines.

As shown in Figures 1, 3 and 4, the adaptive adjustment link assembly 5 includes an upper link 51, a lower link 52 and a middle tension spring 53. Wherein, the upper end of the upper link 51 is connected to the lower end of the upper clamp 32 through a hinge, and the lower end of the lower link 52 is connected to the upper end of the lower clamp 42 through a hinge. 51 is connected to the lower link 52 through a hinge; the middle tension spring 53 is used to provide power for the upper clamp 32, the lower clamp 42, the upper link 51, and the lower link 52 to autonomously return to the initial state, as shown The inner end of the middle tension spring 53 is hooked on the lower end of the upper connecting rod 51, and the outer end of the middle tension spring 53 is hooked on the vertical support plate 21.

As shown in Figures 1, 3 and 4, the upper clamp 32 includes an upper rigid support plate 321 and an upper anti-slip layer 322. The upper anti-slip layer 322 is fixed to the upper rigid support plate through screws and adhesives. 321, and there are transverse anti-slip ribs on the surface of the upper anti-slip layer 322, which can increase the friction between the upper anti-slip layer 322 and the workpiece 6 and prevent the workpiece from slipping during the grabbing process; The lower clamping jaw 42 includes a lower rigid support plate 421 and a lower anti-slip layer 422. The lower anti-slip layer 422 is fixed on the inner side of the lower rigid support plate 421 through screws and adhesives, and on the lower anti-slip layer The surface of 422 is provided with transverse anti-slip ribs, which can increase the friction between the lower anti-slip layer 422 and the workpiece 6 and prevent the workpiece from slipping during the grabbing process. The upper rigid support plate 321 and the lower rigid support plate 421 are made of aluminum alloy materials, which can reduce the weight of the upper rigid support plate 321 and the lower rigid support plate 421; the upper anti-skid layer 322 and the lower anti-skid layer 422 The material adopts PVC made of polyester fiber cloth and polyvinyl chloride glue or wear-resistant rubber made of natural rubber and reinforced fiber to ensure that when the present invention performs the task of grabbing the workpiece 6, the upper clamping claw 32 and the lower clamping There is sufficient friction between the claw 42 and the workpiece 6.

As shown in Figure 1, Figure 3 and Figure 4, the number of the upper clamping device 3 and the lower clamping device 4 is 4, which can ensure sufficient support and clamping points for the grabbed workpiece 6; each group The upper clamping jaws 32 and the lower clamping jaws 42 in the upper clamping device 3 and the lower clamping device 4 are independently driven and controlled by the corresponding upper clamping cylinder 31 and lower clamping cylinder 41, which can realize the grasping of the workpiece 6 The adaptive adjustment and effective clamping of the outer surface can not only grasp cylindrical workpieces, but also realize the grasping of truncated cone-shaped workpieces.

During use, first determine the driving mode of the upper clamping cylinder 31 and the lower clamping cylinder 41 according to the shape of the workpiece 6 to be grabbed. When the workpiece 6 to be grasped is a truncated cone, the upper clamping cylinder 31 and the lower clamping cylinder 41 adopt an asynchronous isobaric driving mode to drive the upper clamping jaw 32 and the lower clamping jaw 42 to clamp the grasped workpiece 6 from the outside. ; When the workpiece 6 to be grabbed is a cylinder, the upper clamping cylinder 31 and the lower clamping cylinder 41 adopt a synchronous isobaric drive mode to drive the upper clamping jaw 32 and the lower clamping jaw 42 to clamp the grabbed workpiece 6 from the outside. tight.

When performing work tasks, a binocular vision system needs to be installed at the end of the hand of the casting robot to collect the situation of the grabbed workpiece being placed on site and to identify, judge and make decisions about the shape, size and position of the grabbed workpiece 6.

In the description of the present invention, it should be understood that the terms "upper", "lower", "vertical", "top", "inner", "outer", "horizontal", etc. indicate an orientation or positional relationship based on The orientation or positional relationship shown in the drawings is only to facilitate the description of the present invention and simplify the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as Limitations on the invention.

The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the industry should understand that the present invention is not limited by the above embodiments. The above embodiments and descriptions only illustrate the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will also have other aspects. Various changes and modifications are possible, which fall within the scope of the claimed invention. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims (5)

1. The utility model provides a casting robot is with self-adaptation pneumatic tongs, includes connection support, main support, goes up clamping device, down clamping device and self-adaptation regulation link assembly, its characterized in that: the connecting support comprises a connecting flange and a connecting support plate, wherein the connecting flange is provided with a mounting hole connected with a hand flange of the casting robot, the inner side end of the connecting support plate is fixedly connected with the connecting flange, and the outer side end of the connecting support plate is fixedly connected with the upper end of the main support; the main support is positioned below the connecting support, the upper clamping device and the lower clamping device are respectively and fixedly arranged at the upper end and the lower end of the main support, and the upper clamping device and the lower clamping device are connected through a self-adaptive adjusting connecting rod assembly; the self-adaptive adjusting connecting rod assembly is arranged at the middle part of the inner side of the main bracket, the upper end of the self-adaptive adjusting connecting rod assembly is connected with the lower end of the upper clamping device through a hinge, and the lower end of the self-adaptive adjusting connecting rod assembly is connected with the upper end of the lower clamping device through a hinge;

the main support comprises a vertical support plate, an upper coaming and a lower coaming, wherein the upper coaming is positioned at the upper end of the vertical support plate and fixedly connected with the vertical support plate, the lower coaming is positioned at the lower end of the vertical support plate and fixedly connected with the vertical support plate, and the upper coaming is fixedly connected with the outer side of the connecting support plate in the connecting support;

the upper clamping device comprises an upper clamping cylinder, an upper clamping jaw and an upper tension spring, wherein a cylinder body part of the upper clamping cylinder is arranged outside the upper end of the vertical support plate, the front end of a piston rod of the upper clamping cylinder is positioned inside the upper end of the vertical support plate, the upper clamping jaw is positioned at the upper end of the inside of the main support, and the front end of the piston rod of the upper clamping cylinder is connected with the middle part of the upper clamping jaw through a hinge; the upper tension spring is positioned at the inner side of the upper end of the vertical support plate and above the piston rod of the upper clamping cylinder, the inner side end of the upper tension spring is hooked on the upper clamping jaw, and the outer side end of the upper tension spring is hooked on the vertical support plate;

the lower clamping device comprises a lower clamping cylinder, a lower clamping jaw and a lower tension spring, wherein the cylinder body part of the lower clamping cylinder is arranged outside the lower end of the vertical support plate, the front end of a piston rod of the lower clamping cylinder is positioned inside the lower end of the vertical support plate, the lower clamping jaw is positioned at the lower end of the inner part of the main support, and the front end of the piston rod of the lower clamping cylinder is connected with the middle part of the lower clamping jaw through a hinge; the lower tension spring is positioned at the inner side of the lower end of the vertical support plate and below the piston rod of the lower clamping cylinder, the inner side end of the lower tension spring is hooked on the lower clamping jaw, and the outer side end of the upper tension spring is hooked on the vertical support plate;

the self-adaptive adjusting connecting rod assembly comprises an upper connecting rod, a lower connecting rod and a middle tension spring, wherein the upper end of the upper connecting rod is connected with the lower end of the upper clamping jaw through a hinge, the lower end of the lower connecting rod is connected with the upper end of the lower clamping jaw through a hinge, and the upper connecting rod is connected with the lower connecting rod through a hinge; the inner side end of the middle tension spring is hooked at the lower end of the upper connecting rod, and the outer side end of the middle tension spring is hooked on the vertical support plate.

2. An adaptive pneumatic gripper for a casting robot as claimed in claim 1, wherein: the upper clamping jaw comprises an upper rigid supporting plate and an upper anti-slip layer, the upper anti-slip layer is fixed on the inner side surface of the upper rigid supporting plate through screws and an adhesive, and transverse anti-slip ribs are arranged on the surface of the upper anti-slip layer; the lower clamping jaw comprises a lower rigid supporting plate and a lower anti-slip layer, wherein the lower anti-slip layer is fixed on the inner side surface of the lower rigid supporting plate through screws and an adhesive, and transverse anti-slip ribs are arranged on the surface of the lower anti-slip layer.

3. An adaptive pneumatic gripper for a casting robot as claimed in claim 1, wherein: the upper clamping cylinder and the lower clamping cylinder are double-acting cylinders; the upper clamping cylinder and the lower clamping cylinder are connected with the electromagnetic directional valve, the safety valve and the air source through pipelines.

4. An adaptive pneumatic gripper for a casting robot as claimed in claim 1, wherein: the number of the upper clamping devices and the lower clamping devices is 3-6, and the upper clamping jaw and the lower clamping jaw in each group of the upper clamping devices and the lower clamping devices are independently driven and controlled by corresponding upper clamping cylinders and lower clamping cylinders.

5. An adaptive pneumatic gripper for a casting robot as claimed in claim 2, wherein: the upper anti-slip layer and the lower anti-slip layer are made of PVC made of polyester fiber cloth and polyvinyl chloride rubber or wear-resistant rubber made of natural rubber and reinforcing fiber.