Workpiece clamping device

Abstract

This invention discloses a workpiece clamping device. The workpiece has an inner hole and includes: a base with a mounting groove for accommodating the workpiece; a driving assembly, a transmission assembly, a clamping assembly, and an adsorption assembly, all disposed inside the base; the driving assembly is connected to the clamping assembly via the transmission assembly, and the adsorption assembly is disposed on the clamping assembly; the driving assembly drives the transmission assembly to move, and the transmission assembly drives the clamping assembly to reciprocate. This invention adds a negative pressure adsorption structure to the rigid clamping mechanism, which can continuously apply a uniform negative pressure adsorption force to the inner hole wall of the workpiece, dispersing the concentrated stress generated by rigid clamping, effectively preventing the thin-walled workpiece from being squeezed and deformed due to excessive local force, and achieving non-destructive clamping of thin-walled workpieces.

Description

Technical Field

[0001] This invention relates to the field of clamping device technology, and more particularly to a workpiece clamping device. Background Technology

[0002] Existing internal workpiece clamping devices mostly employ a purely rigid internal support clamping method, relying on the rigid structure to forcefully compress the inner wall of the workpiece to achieve fixation. This clamping method has significant drawbacks. For thin-walled internal workpieces, the single-point, hard clamping force of the rigid structure is concentrated and cannot evenly conform to the inner wall of the workpiece. This easily leads to indentation and deformation of the thin-walled workpiece under pressure, directly causing the workpiece to be scrapped, and failing to meet the requirements for non-destructive clamping and processing of thin-walled workpieces. Summary of the Invention

[0003] In order to solve the technical problems existing in the background art, the present invention proposes a workpiece clamping device.

[0004] The present invention provides a workpiece clamping device, wherein the workpiece has an inner hole, comprising: A base, on which mounting grooves are provided for accommodating workpieces; The driving assembly, transmission assembly, support assembly, and adsorption assembly are all located inside the base. The drive assembly is connected to the tensioning assembly via the transmission assembly, and the adsorption assembly is mounted on the tensioning assembly. The drive component is used to drive the transmission component to move, and the transmission component drives the tensioning component to reciprocate. The clamping assembly has a clamping part, which is used to expand outward during reciprocating motion and act on the inner hole wall of the workpiece on the mounting groove to clamp the workpiece. The adsorption component is used to apply an adsorption force to the inner wall of the workpiece when the tensioning component is tightening the inner wall of the workpiece.

[0005] Preferably, the drive assembly includes a cylinder body and a piston rod. The cylinder body is fixedly disposed at the bottom of the mounting groove, and the piston rod is reciprocally disposed within the cylinder body, with one end of the piston rod extending out of the cylinder body and connected to the transmission assembly. The cylinder body drives the piston rod to reciprocate along its axial direction, thereby driving the tensioning assembly to reciprocate through the transmission assembly.

[0006] Preferably, the transmission assembly includes a crossbar and two fixed rods. The crossbar is fixedly installed at the end of the piston rod extending out of the cylinder body, and the two fixed rods are respectively fixedly installed inside the base, and the two fixed rods are symmetrically arranged with respect to the axis of the piston rod. The tensioning assembly includes two support rods, which are movably connected to both ends of the crossbar. Each support rod has an inclined groove inside, and the two fixed rods are correspondingly arranged in the two inclined grooves, with the fixed rods slidingly engaged with the inclined grooves. When the piston rod reciprocates along its axial direction, the crossbar drives the two support rods to move along the axial direction of the piston rod, and the fixed rods slide relative to each other in the inclined grooves, converting the axial movement of the support rods into lateral movement along the length of the crossbar.

[0007] Preferably, the tensioning assembly further includes two locking rods, which are installed one-to-one at the ends of the two support rods, and the two locking rods together constitute the tensioning part; the two support rods are driven by the transmission assembly to make lateral reciprocating movements toward or away from each other, and the two locking rods move synchronously with the two support rods; as the two locking rods move away from each other, they expand outward and abut against the inner hole wall of the workpiece to confine the workpiece to the mounting groove from the inside. The mounting groove has an expansion groove at the opening, which is used to accommodate the end of the workpiece when it is placed in the mounting groove. The end of the workpiece abuts against the groove wall to limit the workpiece from going deeper into the mounting groove. The two locking rods clamp the workpiece at the location of the expansion groove. As the two locking rods move closer to each other, they retract inward and disengage from the inner hole wall of the workpiece.

[0008] Preferably, the adsorption assembly is disposed on two clamping rods. The adsorption assembly includes a suction cup, an air passage, and a connector. The suction cup is installed on the side surface of the clamping rod facing the inner wall of the workpiece hole. The air passage is opened inside the clamping rod and the support rod. The connector is disposed on the base and communicates with the air passage. The connector is used to connect to an external negative pressure source.

[0009] Preferably, the suction cup is connected to an external negative pressure source through an air passage and a connector; when the external negative pressure source is turned on, the suction cup, with the clamping rod holding the inner hole wall of the workpiece in place, adsorbs the inner hole wall of the workpiece through negative pressure; when the external negative pressure source is turned off, the suction cup releases its adsorption on the inner hole wall of the workpiece.

[0010] Preferably, the edge of the suction cup is provided with an elastic buffer pad, which is used to provide elastic support force during the process of the clamping assembly clamping the inner wall of the workpiece.

[0011] The workpiece clamping device proposed in this invention has the following advantages: Based on rigid clamping, a negative pressure adsorption structure is added, which continuously applies a uniform negative pressure adsorption force to the inner wall of the workpiece, dispersing the concentrated stress generated by rigid clamping. This effectively prevents the thin-walled workpiece from being squeezed and deformed due to excessive local force, achieving non-destructive clamping of thin-walled workpieces. The negative pressure adsorption combined with an elastic buffer pad ensures that the suction cup completely conforms to the inner wall of the workpiece, maintaining a uniform contact throughout the process. This not only compensates for the large contact gap problem of rigid clamping but also continuously stabilizes the workpiece clamping shape, further preventing deformation of thin-walled workpieces and improving clamping adaptability and processing qualification rate. Attached Figure Description

[0012] Figure 1 This is an internal structural diagram of a workpiece clamping device proposed in this invention; Figure 2 This is an external structural diagram of a workpiece clamping device proposed in this invention; Figure 3 This is a schematic diagram of a workpiece clamping device proposed in this invention when the workpiece is not clamped. Figure 4 This is a schematic diagram of a workpiece clamping device according to the present invention clamping a workpiece. Detailed Implementation

[0013] refer to Figure 1-4 This invention proposes a workpiece clamping device suitable for clamping and fixing workpieces with internal holes. Designed specifically for workpiece internal hole clamping scenarios, this device achieves internal positioning, rigid support, and negative pressure adsorption combined fixing of the workpiece. It features high overall structural integration and strong clamping stability. The device includes a base 1 with a mounting groove 2 for accommodating the workpiece. The workpiece can be placed inside the mounting groove 2, completing the initial positioning and placement of the workpiece.

[0014] This device also includes a drive assembly, a transmission assembly, a clamping assembly, and an adsorption assembly. All three are integrally mounted inside the base 1. The drive assembly drives the transmission assembly in a synchronous reciprocating motion. During this motion, the transmission assembly drives the clamping assembly in a reciprocating motion. The clamping assembly is equipped with a dedicated clamping part. As the clamping assembly completes its reciprocating motion, the clamping part can switch between outward expansion and inward contraction. In the outward expansion state, the clamping part can directly adhere to the inner wall of the workpiece placed inside the mounting slot, clamping and fixing the workpiece from within and restricting its displacement. The adsorption assembly is configured to match the working state of the clamping assembly. Under the simultaneous working conditions of the clamping assembly expanding outward and rigidly clamping the inner wall of the workpiece, it continuously applies negative pressure adsorption force to the inner wall of the workpiece, preventing deformation of thin-walled workpieces.

[0015] The drive assembly includes a cylinder body and a piston rod 3. The cylinder body is mounted at the bottom of the mounting groove 2, and the piston rod 3 is reciprocally mounted within the cylinder body. The axial direction of the piston rod 3 is parallel to the depth direction of the mounting groove 2, and the extended end of the piston rod 3 is fixedly connected to the transmission assembly. The cylinder body can drive the piston rod 3 to reciprocate linearly along its own axis, indirectly driving the entire tensioning assembly to complete the reciprocating motion through the transmission assembly, providing power for the opening and closing actions of the tensioning assembly.

[0016] The transmission assembly includes a crossbar 4 and two fixed rods 5. The crossbar 4 is horizontally fixed at the end of the piston rod 3 extending out of the cylinder body. The crossbar 4 is vertically fixed to the piston rod 3 and can move axially back and forth synchronously with the piston rod 3. The two fixed rods 5 are both fixedly installed inside the base 1. The fixed rods 5 and the base 1 are an integral fixed structure with no relative movement. The two fixed rods 5 are symmetrically distributed about the central axis of the piston rod 3.

[0017] The tensioning assembly includes two support rods 6, the tops of which are hinged to the two ends of the crossbar 4, allowing the support rods 6 to deflect at an angle relative to the ends of the crossbar 4. Each support rod 6 has an inclined groove 7 inside its body, which is a through-groove structure. Two fixed rods 5 are respectively inserted into the two inclined grooves 7, with the outer wall of the fixed rod 5 slidingly engaging with the groove wall of the inclined groove 7. When the piston rod 3 reciprocates axially along its own axis, it drives the crossbar 4 to move axially in sync. The crossbar 4 pulls the two support rods 6 to move axially in sync. During this movement, the fixed rods 5 remain stationary, while the inclined grooves 7 slide relative to the fixed rods 5. Through the engagement structure between the inclined grooves 7 and the fixed rods 5, the axial linear motion of the support rods 6 is converted into lateral linear motion along the length of the crossbar 4, enabling the two support rods 6 to move closer and further apart.

[0018] The tensioning assembly also includes two locking rods 8, which are respectively fixedly installed at the outer ends of the two support rods 6. The locking rods 8 and the support rods 6 are rigidly connected with each other without relative displacement. The two locking rods 8 together form the tensioning part of the device, serving as the working structure that directly contacts the inner hole of the workpiece. Under the power conversion action of the transmission assembly, the two support rods 6 can complete lateral reciprocating motions, moving closer to or further away from each other. The two locking rods 8 follow the corresponding support rods 6 synchronously in completing lateral displacement, maintaining complete synchronization of their movements.

[0019] During the lateral movement of the two clamping rods 8 as they move away from each other, the two clamping rods 8 simultaneously expand outwards. A ring of protrusions is provided inside the workpiece, and the ends of the clamping rods 8 press against the protrusions from the inside, forming a clamping and limiting position on the workpiece from within, thus fixing the workpiece within the mounting groove 2 and restricting its displacement. A ring of expansion grooves 9 is formed at the opening of the mounting groove 2. When the workpiece is placed inside the mounting groove 2, its end can be embedded into the groove of the expansion groove 9, with the end face of the workpiece abutting against the groove wall of the expansion groove 9. This restricts the longitudinal displacement of the workpiece along the depth direction of the mounting groove 2, preventing excessive sinking of the workpiece. The working positions of the two clamping rods 8 correspond to the placement of the expansion grooves 9, and the clamping rods 8 perform the clamping and locking operation on the inner hole of the workpiece within the area of ​​the expansion grooves 9. During the lateral movement of the two clamping rods 8 as they move closer to each other, the two clamping rods 8 simultaneously retract inwards, and the outer walls of the clamping rods 8 completely disengage from the inner hole wall of the workpiece, releasing the internal clamping and limiting position on the workpiece, allowing for direct disassembly and removal of the workpiece.

[0020] The adsorption assembly is integrally mounted on two clamping rods 8. The adsorption assembly includes a suction cup 10, an air passage, and a connector. The suction cup 10 is fixedly installed on the side of the clamping rod 8 facing the inner wall of the workpiece's hole, and the adsorption working surface of the suction cup 10 is flush with the outer end face of the clamping rod 8. The air passage is a closed-loop structure, located within the internal cavities of the clamping rod 8 and the support rod 6, respectively. The air passages inside the clamping rod 8 and the support rod 6 are interconnected, forming a complete airflow path. The connector is fixedly mounted at a predetermined position on the outer surface of the base 1. The inner end of the connector connects to the end of the air passage inside the support rod 6, and the outer end of the connector is an external interface structure, allowing connection to an external negative pressure source device.

[0021] The suction cup 10 forms a connecting passage with the connector through interconnected air channels, and the entire air passage is in a sealed state. When the external negative pressure source is turned on, the negative pressure airflow is conducted to the suction cup 10 through the connector and air channels. When the clamping rod 8 is pressed tightly against the inner wall of the workpiece's hole, a negative pressure cavity is formed between the working surface of the suction cup 10 and the inner wall of the workpiece. The workpiece's inner wall is fixed by negative pressure adsorption, and the auxiliary clamping component completes the workpiece fixation. At the same time, the edge of the suction cup 10 is provided with an elastic buffer pad, which provides elastic support force during the clamping rod 8's tightening of the workpiece's inner wall, buffering the rigid pressing contact stress and adapting to the workpiece's inner wall adhesion and fixation requirements. When the external negative pressure source is turned off, the negative pressure inside the suction cup 10 dissipates, releasing the adsorption and fixation state on the inner wall of the workpiece's hole.

[0022] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A workpiece holding device, the workpiece having an internal bore, characterized by, include: The base (1) has a mounting groove (2) for accommodating the workpiece. The driving component, transmission component, support component and adsorption component are all disposed inside the base (1); The drive assembly is connected to the tensioning assembly via the transmission assembly, and the adsorption assembly is mounted on the tensioning assembly. The drive component is used to drive the transmission component to move, and the transmission component drives the tensioning component to reciprocate. The clamping assembly has a clamping part, which is used to open outward during reciprocating motion and act on the inner hole wall of the workpiece on the mounting groove (2) to clamp the workpiece. The adsorption component is used to apply an adsorption force to the inner wall of the workpiece when the tensioning component is tightening the inner wall of the workpiece.

2. A workpiece holding device according to claim 1, wherein The drive assembly includes a cylinder body and a piston rod (3). The cylinder body is fixedly installed at the bottom of the mounting groove (2). The piston rod (3) is reciprocally installed in the cylinder body, and one end of the piston rod (3) extends out of the cylinder body and is connected to the transmission assembly. The cylinder body drives the piston rod (3) to reciprocate along its axial direction, thereby driving the tensioning assembly to reciprocate through the transmission assembly.

3. A workpiece holding device according to claim 2, wherein The transmission assembly includes a crossbar (4) and two fixed rods (5). The crossbar (4) is fixedly installed at one end of the piston rod (3) extending out of the cylinder body. The two fixed rods (5) are respectively fixedly installed inside the base (1), and the two fixed rods (5) are arranged symmetrically with respect to the axis of the piston rod (3). The tensioning assembly includes two support rods (6). The two support rods (6) are movably connected to the two ends of the crossbar (4). The interior of the two support rods (6) is provided with inclined grooves (7). The two fixed rods (5) are correspondingly set in the two inclined grooves (7), and the fixed rods (5) slide in the inclined grooves (7). When the piston rod (3) moves back and forth along its axial direction, the crossbar (4) drives the two support rods (6) to move along the axial direction of the piston rod (3). The fixed rods (5) slide relative to each other in the inclined grooves (7), converting the axial movement of the support rods (6) into lateral movement along the length direction of the crossbar (4).

4. The workpiece clamping device according to claim 3, characterized in that, The tensioning assembly also includes two locking rods (8), which are installed one-to-one at the ends of the two support rods (6). The two locking rods (8) together constitute the tensioning part. The two support rods (6) move laterally towards each other or away from each other through the drive of the transmission assembly. The two locking rods (8) move synchronously with the two support rods (6). As the two locking rods (8) move away from each other, they are pushed outward and abut against the inner wall of the workpiece to confine the workpiece from the inside. On the mounting groove (2), there is a ring of expansion groove (9) at the opening of the mounting groove (2). The expansion groove (9) is used to accommodate the end of the workpiece when the workpiece is placed in the mounting groove (2). The end of the workpiece abuts against the groove wall of the expansion groove (9) to limit the workpiece from going deeper along the depth direction of the mounting groove (2). Two clamping rods (8) clamp the workpiece at the location of the expansion groove (9). As the two clamping rods (8) approach each other, the two clamping rods (8) retract inward and disengage from the inner hole wall of the workpiece.

5. The workpiece clamping device according to claim 4, characterized in that, The adsorption assembly is set on two clamps (8). The adsorption assembly includes a suction cup (10), an air passage and a connector. The suction cup (10) is installed on the side surface of the clamp (8) facing the inner wall of the workpiece hole. The air passage is opened inside the clamp (8) and the support rod (6). The connector is set on the base (1) and communicates with the air passage. The connector is used to connect to an external negative pressure source.

6. The workpiece clamping device according to claim 5, characterized in that, The suction cup (10) is connected to an external negative pressure source through an air passage and a connector. When the external negative pressure source is turned on, the suction cup (10) adsorbs the inner hole wall of the workpiece by negative pressure while the clamping rod (8) holds the inner hole wall of the workpiece. When the external negative pressure source is turned off, the suction cup (10) releases the adsorption on the inner hole wall of the workpiece.

7. A workpiece clamping device according to claim 6, characterized in that, The edge of the suction cup (10) is provided with an elastic buffer pad, which is used to provide elastic support force during the process of the clamping assembly clamping the inner wall of the workpiece.

Images