A workpiece positioning device for a servo punching machine

Abstract

The present invention relates to the field of punching presses and discloses a workpiece positioning device for a servo punching press. It includes a clamping composite member, a driving mechanism, a thermal deformation compensation mechanism, and a substrate. A punching fixed die is installed on the substrate. There are two clamping composite members, and the two clamping composite members slide on both sides of the punching fixed die respectively to clamp or release the workpiece. The driving mechanism is connected to the two clamping composite members to drive the two clamping composite members to move synchronously. There are two sets of thermal deformation compensation mechanisms, and the two sets of thermal deformation compensation mechanisms correspond to the two clamping composite members respectively; when the side of the clamping composite member close to the workpiece warps, the thermal deformation compensation mechanism will drive the clamping composite member to move away from the workpiece under the action of high temperature to compensate for the warping. The thermal deformation compensation mechanism of the present invention can drive the clamping composite member to move in the opposite direction of warping after being heated to compensate for the warping value caused by the thermal deformation of the clamping composite member; improve the machining accuracy of the workpiece; and improve the service life of the workpiece positioning device.

Description

Technical Field

[0001] The present invention relates to the technical field of punching machines, and more specifically, to a workpiece positioning device for a servo punching machine. Background Art

[0002] Due to the high stability of servo punching machines, servo punching machines are widely used in the stamping industry. In order to improve the stamping efficiency of servo punching machines for workpieces, a workpiece positioning device is usually provided on the punching machine, and an automatic loading and unloading mechanism is provided on one side of the punching machine. The workpiece is transported to the workpiece positioning device through the automatic loading and unloading mechanism. Then, the stamping mechanism on the punching machine stamps the workpiece located on the workpiece positioning device, and the stamped workpiece will be automatically unloaded from the workpiece positioning device through the automatic loading and unloading mechanism, so that the punching machine can continuously stamp. The existing tooling positioning device includes two clamping members that move towards or away from each other simultaneously. The two clamping members are synchronously moved towards or away from each other under the action of a motor and a bidirectional lead screw to clamp the workpiece to be stamped, making it difficult for the workpiece to shift and improving the stamping accuracy of the workpiece.

[0003] However, during the operation of the punching machine, cutting heat and frictional heat will be generated. After the punching machine continuously stamps for a long time, these heats will also be transmitted to the two clamping members, resulting in different degrees of thermal deformation on the side of the two clamping members that clamp the workpiece. However, since the distance that the two clamping members are driven to move by the motor and the bidirectional lead screw each time is the same, and the existing workpiece positioning device does not have a compensation mechanism, when the two clamping members have different degrees of thermal deformation, the workpiece will be over-clamped, affecting the service life of the workpiece positioning device; or a small gap will be generated between the workpiece and the workpiece, affecting the stamping accuracy of the workpiece. Summary of the Invention

[0004] To solve at least one of the above problems, the present invention provides a workpiece positioning device for a servo punching machine, including a clamping composite member, a driving mechanism, a thermal deformation compensation mechanism, and a substrate. The substrate is adapted to be fixedly installed on the punching machine. A punching fixed die for placing the workpiece is installed on the substrate. There are two clamping composite members, and the two clamping composite members are respectively slidably arranged on both sides of the punching fixed die to clamp or release the workpiece. The driving mechanism is arranged on the substrate and is connected to the two clamping composite members and is adapted to drive the two clamping composite members to move synchronously towards or away from each other. The thermal deformation compensation mechanism is movably connected to the substrate. There are two groups of thermal deformation compensation mechanisms, and the two groups of thermal deformation compensation mechanisms respectively correspond to the two clamping composite members one by one. When the side of the clamping composite member close to the workpiece is heated, the clamping composite member will warp towards the side where the workpiece is located. At this time, the thermal deformation compensation mechanism will drive the clamping composite member to move away from the workpiece under the action of high temperature to compensate for the warping.

[0005] Optionally, the clamping composite includes a plurality of invar plates and a plurality of aluminum alloy plates. The plurality of invar plates and the plurality of aluminum alloy plates are stacked alternately in sequence and then connected by rivets. The stacking direction of the plurality of invar plates and the plurality of aluminum alloy plates is the sliding direction of the clamping composite. Both the side of the clamping composite close to the workpiece and the side away from the workpiece are invar plates.

[0006] Optionally, the thickness ratio of the invar plate to the aluminum alloy plate is 3:5.

[0007] Optionally, a sliding plate is slidably connected to the base plate. The sliding plate is connected to the driving mechanism. The clamping composite is arranged on the sliding plate. The clamping composite can slide synchronously with the sliding plate, and the clamping composite can move relative to the sliding plate under the drive of the thermal deformation compensation mechanism.

[0008] Optionally, the clamping composite further includes a U-shaped plate. A plurality of invar plates and a plurality of aluminum alloy plates are fixedly installed in the U-shaped plate. A small guide rail group is arranged on the top of the sliding plate. The U-shaped plate is connected to the small guide rail group to be suitable for moving relative to the sliding plate.

[0009] Optionally, the thermal deformation compensation mechanism includes a copper bellows and a plastic slider. An installation groove is formed on the side of the clamping composite away from the stamping fixed die. The installation groove does not penetrate through the clamping composite. One end of the copper bellows is inserted into the installation groove and fixedly connected to the bottom of the installation groove. The maximum outer diameter of the copper bellows is equal to the groove diameter of the installation groove. The plastic slider is slidably arranged on the side of the clamping composite away from the stamping fixed die. One end of the copper bellows away from the bottom of the installation groove is fixedly connected to the plastic slider. High-viscosity silicone oil is injected into the copper bellows. The high-viscosity silicone oil fills the entire copper bellows. When heated, the high-viscosity silicone oil expands thermally, driving the copper bellows to extend to push the plastic slider to move.

[0010] Optionally, the thermal deformation compensation mechanism further includes a driving threaded column and a fixed block. The fixed block is located on one side of the plastic slider. The plastic slider and the clamping composite are suitable for moving relative to the fixed block. One end of the driving threaded column passes through the fixed block and is threadedly connected to the fixed block. When the plastic slider moves, it will drive the driving threaded column to rotate and move relative to the fixed block. One end of the driving threaded column is rotatably connected to the clamping composite. A retaining piece is fixedly installed on the side of the clamping composite connected to the driving threaded column. The retaining piece is suitable for driving the clamping composite and the driving threaded column to move synchronously relative to the fixed block.

[0011] Optionally, the thermal deformation compensation mechanism further includes a lead screw body, a ball screw nut, and a fixing plate. The fixing plate is fixedly arranged on the side of the plastic slider away from the clamping composite. The ball screw nut is rotatably connected to the fixing plate. One end of the lead screw body is fixedly connected to the plastic slider, and the other end is inserted into the ball screw nut and threadedly engaged with the ball screw nut. When the lead screw body moves, it will drive the ball screw nut to rotate, so as to drive the driving threaded column to rotate.

[0012] Optionally, the thermal deformation compensation mechanism further includes a driving gear and a driven gear. The driving gear is sleeved on the ball screw nut and rotates synchronously with the ball screw nut. The driven gear is sleeved on the driving threaded column and rotates synchronously with the driving threaded column. The driving gear is engaged with the driven gear.

[0013] Optionally, the thickness of the driven gear is greater than that of the driving gear; a rotating bearing is arranged on the fixing plate, the ball screw nut is press-fitted into the rotating bearing, and a lubricating grease is applied to the threaded connection between the driving threaded column and the fixing block.

[0014] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0015] 1. The aluminum alloy plate can quickly respond to temperature changes. Since the invar plate has high stiffness and small expansion amount, the invar plate will limit the free expansion of the aluminum alloy plate and force the whole laminate to bend towards the invar plate side (opposite to the thermal expansion direction of a single material), which can offset the linear thermal elongation to a certain extent. In addition, the staggered stacking arrangement, through the differential deformation mechanism of "using heat to counteract heat", the thermal deformation compensation mechanism can drive the clamping composite to move in the opposite direction of warping after being heated to compensate for the warping value caused by the thermal deformation of the clamping composite, improving the machining accuracy of the workpiece.

[0016] 2. The copper bellows has good thermal conductivity and ductility. After the temperature rises, since the inside of the copper bellows is filled with high-viscosity silicone oil, the volume of the high-viscosity silicone oil will expand significantly after being heated. Then the copper bellows will push the plastic slider to move under pressure, and further drive the driving threaded column to rotate to drive the clamping composite to move in the opposite direction for compensation. After the temperature drops, the volume of the high-viscosity silicone oil shrinks, and the copper bellows also shrinks under pressure. The cooperation of the copper bellows and the high-viscosity silicone oil can respond in a timely manner. At the same time, the copper bellows is not prone to fatigue fracture during repeated expansion and contraction, improving the stability and service life of the thermal deformation compensation mechanism.

[0017] 3. When the copper bellows expands and contracts, its own thrust is limited. The cooperation between the screw rod body and the ball screw nut has a very small frictional resistance. The ball screw nut is inserted into the rotating bearing, and the plastic slider is lighter than the metal material. Therefore, the copper bellows does not need to apply a large thrust to the plastic slider to drive the ball screw nut to drive the driving gear to rotate;

[0018] 4. Apply grease to the threaded connection between the driving threaded column and the fixed block to make the frictional force between the driving threaded column and the fixed block smaller when the driving threaded column rotates. When the driving gear drives the driven gear to rotate, it does not require a large torque. In addition, since the driving threaded column and the fixed block are in threaded cooperation, and one end of the driving threaded column is connected to the clamping composite member to limit the movement of the clamping composite member, the clamping composite member will not move when it is subjected to the axial force of the driving threaded column. Therefore, the clamping composite member can be driven to move and compensated by a relatively small torque of the driving threaded column. When the driving threaded column is stationary, it can also improve the stability of limiting the movement of the clamping composite member. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural diagram of the clamping composite member, the driving mechanism and the thermal deformation compensation mechanism in the embodiment of the present invention;

[0020] Figure 2 It is an exploded view of the clamping composite member, the driving mechanism and the thermal deformation compensation mechanism in the embodiment of the present invention;

[0021] Figure 3 It is an exploded view of the clamping composite member and the thermal deformation compensation mechanism in the embodiment of the present invention Figure 1 ;

[0022] Figure 4 It is an exploded view of the clamping composite member and the thermal deformation compensation mechanism in the embodiment of the present invention Figure 2 ;

[0023] Figure 5 It is a schematic diagram of clamping a workpiece by the clamping composite member when no warping occurs in the embodiment of the present invention;

[0024] Figure 6 It is a schematic diagram of clamping a workpiece by the clamping composite member after warping occurs in the embodiment of the present invention.

[0025] Description of the reference numerals: 1. Clamping composite member; 11. Invar steel plate; 12. Aluminum alloy plate; 13. U-shaped plate; 14. Installation groove; 15. Miniature bearing; 16. Retaining piece; 2. Driving mechanism; 3. Thermal deformation compensation mechanism; 31. Copper bellows; 32. Plastic slider; 33. Driving threaded column; 34. Fixed block; 35. Screw rod body; 36. Ball screw nut; 37. Fixed plate; 38. Driving gear; 39. Driven gear; 4. Substrate; 41. Stamping fixed die; 42. First guide rail group; 43. Sliding plate; 44. Small guide rail group. Detailed Implementation Manner

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the following further elaborates on this application Figures 1-6 in further detail with reference to the accompanying drawings.

[0027] An embodiment of the present invention provides a workpiece positioning device for a servo punching machine. Referring to Figure 1 and Figure 2 , the workpiece positioning device for the servo punching machine includes a clamping composite member 1, a driving mechanism 2, a thermal deformation compensation mechanism 3, and a substrate 4. The substrate 4 is adapted to be fixedly installed on the servo punching machine. A punching fixed die 41 is installed on the substrate 4. The workpiece to be punched will be placed on the punching fixed die 41 through an automatic loading and unloading mechanism. After the workpiece is punched, it will be loaded and unloaded from the punching fixed die 41 through the automatic loading and unloading mechanism. Two clamping composite members 1 are provided. The two clamping composite members 1 are respectively slidably arranged on both sides of the punching fixed die 41 to clamp or release the workpiece. The driving mechanism 2 is arranged on the substrate 4 and is connected to the two clamping composite members 1 and is adapted to drive the two clamping composite members 1 to move synchronously towards or away from each other. The thermal deformation compensation mechanism 3 is movably connected to the substrate 4. Two sets of thermal deformation compensation mechanisms 3 are provided. The two sets of thermal deformation compensation mechanisms 3 respectively correspond to the two clamping composite members 1 one by one; when one side of the clamping composite member 1 close to the workpiece is heated to a high temperature, the clamping composite member 1 will warp towards the side where the workpiece is located (that is, the clamping composite member 1 will bulge towards the workpiece). At this time, the thermal deformation compensation mechanism 3 will drive the clamping composite member 1 to move away from the workpiece under the action of high temperature to compensate for the warping.

[0028] Among them, when the punching machine continuously punches, the workpiece will also continuously generate a certain amount of frictional heat with the clamping composite member 1. Combining with the temperature generated by the punching machine, the high temperature generated at the punching position of the punching machine is 200°-300°.

[0029] A positioning groove for placing the workpiece is opened at the top of the punching fixed die 41, but both sides of the positioning groove close to the two clamping composite members 1 penetrate the punching fixed die 41. After the workpiece is placed in the positioning groove, both sides of the workpiece close to the two clamping composite members 1 protrude from the groove. On the one hand, it is convenient for the automatic loading and unloading mechanism to clamp and place the workpiece in the positioning groove or take it out of the positioning groove to complete unloading; on the other hand, it is convenient for the clamping composite member 1 to clamp and position the workpiece.

[0030] Referring to Figure 2 and Figure 3, a first guide rail group 42 is installed on the top of the substrate 4. The first guide rail group 42 includes a first linear guide rail and a first slider. The first linear guide rail is fixedly connected to the substrate 4 by bolts, and the first slider slides directionally on the first linear guide rail. There are two first sliders, and sliding plates 43 are respectively installed on the two first sliders by bolts. Both of the two sliding plates 43 are connected to the driving mechanism 2, and the driving mechanism 2 drives the two sliding plates 43 to move synchronously towards or away from each other.

[0031] The driving mechanism 2 includes a driving cylinder, a second guide rail group, a driving plate and articulated connecting rods. The driving cylinder is fixedly connected to the substrate 4. The second guide rail group is located on one side of the stamping fixed die 41. The second guide rail group includes a second linear guide rail and a second slider. The second linear guide rail is fixedly connected to the substrate 4 by bolts, and the second slider slides directionally on the second linear guide rail. The sliding direction of the second slider is perpendicular to the sliding direction of the first slider. The driving plate is installed on the second slider by bolts and slides synchronously with the second slider. The telescopic rod of the driving cylinder is connected to the driving plate, and when the driving cylinder expands and contracts, it will drive the driving plate to move. Since there are two sliding plates 43, there are also two articulated connecting rods. One ends of the two articulated connecting rods are respectively hinged to the driving plate; the other ends are respectively hinged to the two sliding plates 43. When the driving cylinder drives the driving plate to move towards the direction close to the stamping fixed die 41, the two articulated connecting rods will drive the two sliding plates 43 to move away synchronously to release the workpiece.

[0032] Refer to Figure 2 With Figure 3 , two clamping composites 1 are respectively installed on the two sliding plates 43. The clamping composite 1 can slide synchronously with the relative sliding plate 43, and the clamping composite 1 can move relative to the sliding plate 43 under the drive of the thermal deformation compensation mechanism 3 to compensate for the thermal deformation of the clamping composite 1. The two clamping composites 1 and the two groups of thermal deformation compensation mechanisms 3 have the same structure. The structure and cooperation relationship of one clamping composite 1 and the corresponding group of thermal deformation compensation mechanisms 3 will be described below as an example.

[0033] The clamping composite 1 includes Invar plates 11, aluminum alloy plates 12, and U-shaped plates 13. There are multiple Invar plates 11 and multiple aluminum alloy plates 12. After the multiple Invar plates 11 and multiple aluminum alloy plates 12 are stacked alternately in sequence (that is, one Invar plate 11, one aluminum alloy plate 12, one Invar plate 11, and so on), they are connected by rivets. The aluminum alloy plate 12 can quickly respond to temperature changes, and the Invar plate 11 has high stiffness. The Invar plate 11 is inserted between the aluminum alloy plates 12 to form a "skeleton" structure, which restricts the lateral expansion of the aluminum alloy, reduces the local bending effect of the gradient temperature difference, and the ductility of the aluminum alloy and the high strength of the Invar complement each other, improving the anti-cyclic thermal fatigue ability of the substrate 4. The stacking direction of the multiple Invar plates 11 and multiple aluminum alloy plates 12 is the sliding direction of the sliding plate 43. After the multiple Invar plates 11 and multiple aluminum alloy plates 12 are stacked, they are fixedly installed in the U-shaped plate 13 to form a module. A lug plate is welded to the side of the U-shaped plate 13 facing away from the stamping fixed die 41, and the clamping composite 1 is fixedly connected to the lug plate by bolts.

[0034] Referring to Figure 2 With Figure 3 , in this embodiment, it is preferably set that there are four Invar plates 11; there are three aluminum alloy plates 12. Both the side of the clamping composite 1 close to the stamping fixed die 41 and the side far from the stamping fixed die 41 are Invar plates 11, so that the clamping composite 1 has a greater stiffness and is more stable at the places where it contacts external workpieces or other components, improving the service life of the clamping composite 1. The Invar plate 11 on the side close to the stamping fixed die 41 protrudes from the U-shaped plate 13 and the sliding plate 43 to better cooperate with the workpiece.

[0035] Among them, the thickness ratio of the Invar plate 11 to the aluminum alloy plate 12 is 3:5. The thicker aluminum alloy plate 12 provides sufficient thermal deformation driving force, and the thinner Invar plate 11 reduces the weight while ensuring stiffness. In addition, the alternate stacking disperses the expansion stress to each layer interface, reducing the risk of warping or fracture of the single-layer material due to sudden stress.

[0036] A small guide rail group 44 is installed on the top of the sliding plate 43. The small guide rail group 44 includes a small linear guide rail and a small slider. The small linear guide rail is fixed to the top of the sliding plate 43 by bolts, and the small slider slides on the small linear guide rail, and the sliding direction of the small slider is the same as the sliding direction of the sliding plate 43. The U-shaped plate 13 is installed on the small slider by bolts, so that when the U-shaped plate 13 drives the clamping composite 1 to move relative to the sliding plate 43, the frictional resistance is small. Furthermore, the thermal deformation compensation mechanism 3 can drive the U-shaped plate 13 to drive the clamping composite 1 to move to compensate for the warping value by applying a smaller force to the clamping composite 1.

[0037] Combined with Figure 2 Referring to Figure 3 With Figure 4, the thermal deformation compensation mechanism 3 includes a copper bellows 31, a plastic slider 32, a driving threaded column 33 and a fixed block 34. The plastic slider 32 is located on the side of the clamping composite 1 away from the stamping fixed die 41 and can slide relative to the sliding plate 43 on the sliding plate 43. The fixed block 34 and the plastic slider 32 are located on the same side of the clamping composite 1 and are fixed to the sliding plate 43. The driving threaded column 33 is threadedly installed on the fixed block 34 and one end of the driving threaded column 33 is connected to the clamping composite 1. One end of the copper bellows 31 is connected to the clamping composite 1; the other end is connected to the plastic slider 32. When the clamping composite 1 is deformed due to the increase in temperature, the copper bellows 31 will expand at high temperature and push the plastic slider 32 to move. After the plastic slider 32 moves, it will drive the driving threaded column 33 to rotate relative to the fixed block 34 to drive the clamping composite 1 to move away from the stamping fixed die 41 for compensation.

[0038] Among them, a small slider is also slidably provided on the small linear guide. The plastic slider 32 is connected to the other small slider by a bolt, which reduces the friction when the plastic slider 32 slides; in addition, the plastic slider 32 is made of plastic material, so that the plastic slider 32 has a light weight. Therefore, only a small force is required to push the plastic slider 32 when the copper bellows 31 expands.

[0039] Combined with Figure 2 Refer to Figure 3 And Figure 4 , an installation groove 14 is opened on the side of the clamping composite 1 away from the stamping fixed die 41, but the installation groove 14 does not penetrate the entire clamping composite 1 along the opening direction. The copper bellows 31 is a pipe body with only one end open. The end of the copper bellows 31 away from its own opening is inserted into the installation groove 14; and is fixedly connected to the bottom of the installation groove 14 by a bolt, so that when the clamping composite 1 is warped by heat, the heat can be timely transferred to the copper bellows 31 to make the copper bellows 31 react in time. A flange is integrally formed at the open end of the copper bellows 31. The open end of the copper bellows 31 protrudes from the installation groove 14 and is fixedly connected to the plastic slider 32 by cooperating with the bolt through the flange. Therefore, after the copper bellows 31 expands due to heat, it will push the plastic slider 32 to move. The maximum outer diameter of the copper bellows 31 is equal to the groove diameter of the installation groove 14, so that the copper bellows 31 is not easy to expand radially when it expands, but expands along its own axial direction.

[0040] The copper bellows 31 is filled with high-viscosity silicone oil. The high-viscosity silicone oil fills the entire copper bellows 31. On the one hand, the high-viscosity silicone oil has low fluidity, which can slow down the pressure fluctuation when the temperature changes suddenly. On the other hand, the high-viscosity silicone oil is not easy to leak and can ensure sufficient volume expansion to drive the copper bellows 31 to move. After the temperature rises, the volume of the high-viscosity silicone oil expands and becomes larger, and the internal pressure of the copper bellows 31 pushes the folds of itself to unfold and axially elongate to push the plastic slider 32 to move. After the temperature drops, the volume of the high-viscosity silicone oil will become smaller again, forming a negative pressure, which drives the copper bellows 31 to retract along the crease of the fold. Among them, both ends of the copper bellows 31 are sealed, so that the high-viscosity silicone oil is not easy to leak and the copper bellows 31 is more stable every time it expands and contracts.

[0041] Combined with Figure 2 Refer to Figure 3 With Figure 4 On one side of the clamping composite 1 close to the driving threaded column 33, a bearing groove is provided, and a micro-bearing 15 is placed in the bearing groove. One end of the driving threaded column 33 is inserted into the micro-bearing 15 and welded to the micro-bearing 15, so that the driving threaded column 33 can be rotatably connected to the clamping composite 1. At the notch of the bearing groove, an annular retaining piece 16 is installed by bolts. The inner diameter of the retaining piece 16 is larger than the outer diameter of the driving threaded column 33 but smaller than the outer diameter of the micro-bearing 15, and the outer diameter of the retaining piece 16 is larger than the groove diameter of the bearing groove. Therefore, when the driving threaded column 33 moves relative to the fixed block 34, it can drive the clamping composite 1 to move synchronously.

[0042] Combined with Figure 2 Refer to Figure 3 With Figure 4 The thermal deformation compensation mechanism 3 further includes a lead screw body 35, a ball screw nut 36, a fixing plate 37, a driving gear 38 and a driven gear 39. The fixing plate 37 is located on the side of the plastic slider 32 away from the copper bellows 31, and the fixing plate 37 is fixed to the sliding plate 43. The ball screw nut 36 is rotatably connected to the fixing plate 37. One end of the lead screw body 35 is threadedly connected to the plastic slider 32, and the other end is inserted into the ball screw nut 36 and threadedly engaged with the ball screw nut 36. Therefore, when the plastic slider 32 drives the lead screw body 35 to move, the lead screw body 35 can drive the ball screw nut 36 to rotate. The driving gear 38 is sleeved on the ball screw nut 36 and key-connected to the ball screw nut 36 to achieve synchronous rotation. The driven gear 39 is located on the side of the fixed block 34 away from the clamping composite 1. The driven gear 39 is sleeved on the driving threaded column 33 and key-connected to the driving threaded column 33 to achieve synchronous rotation. The driving gear 38 and the driven gear 39 are meshed with each other. Therefore, after the plastic block moves, it can drive the driving gear 38 to rotate, and the driving gear 38 drives the driven gear 39 to drive the driving threaded column 33 to rotate, so as to drive the clamping composite 1 to move.

[0043] Among them, a through hole penetrating through itself is provided on one side of the fixing plate 37 close to the plastic slider 32. A rotating bearing is installed in the through hole, and the ball screw nut 36 is press-fitted into the rotating bearing. Since there are many steel balls inside the ball screw nut 36 itself, the cooperation between the screw rod body 35 and the ball screw nut 36 has a very small frictional resistance; and the ball screw nut 36 is inserted into the rotating bearing, so that the frictional resistance received by the ball screw nut 36 when rotating relative to the fixing plate 37 is small. In addition, lubricating grease is applied to the threaded connection between the driving threaded column 33 and the fixing block 34, so that the resistance when the driving threaded column 33 rotates is small. Furthermore, after the copper bellows 31 extends, only a small force needs to be applied to the plastic sliding block to drive the driving threaded column 33 to rotate to drive the clamping composite 1 to move.

[0044] Combined with Figure 2 Referring to Figure 3 With Figure 4 , since the driven gear 39 will move synchronously along its own axial direction after rotating, the thickness of the driven gear 39 is greater than that of the driving gear 38. Two copper bellows 31, plastic sliders 32, screw rod bodies 35, ball screw nuts 36, driving gears 38, fixing plates 37 and rotating bearings are respectively arranged at intervals on both sides of the fixing block 34, and the two driving gears 38 are meshed with the driven gear 39 respectively, so that the force for driving the driving threaded column 33 to rotate is small.

[0045] It should be noted that by changing the content of the high-viscosity silicone oil in the copper bellows 31; or changing the gear ratio of the driving gear 38 and the driven gear 39, the compensation distance of the clamping composite 1 can be adjusted, so that the compensation distance and the warping degree of the clamping composite 1 are more accurate.

[0046] Referring to Figure 5 With Figure 6 , when the clamping composite 1 does not warp, the copper bellows 31 is in a contracted state. After the clamping composite 1 warps, assuming the warping height of the clamping composite 1 is h, then the copper bellows 31 will also extend a certain length to compensate for the warping height h, so that the two clamping composites 1 always maintain appropriate clamping on the workpiece.

[0047] The implementation principle of the workpiece positioning device for a servo punch in the embodiment of the present application is as follows: the Invar steel plate 11 and the aluminum alloy plate 12 are stacked alternately, and through the differential deformation mechanism of "heating with heat", the high expansion characteristics of the aluminum alloy plate 12 can be converted into compensation advantages. Combining the stability of the Invar steel plate 11, part of the thermal deformation can be actively offset, achieving both precision and stiffness; the Invar steel plate 11 suppresses vibration, and the aluminum alloy plate 12 absorbs impact, making the clamping composite 1 have a long service life and low cost.

[0048] When the clamped composite part 1 warps due to temperature rise, the volume of the high-viscosity silicone oil will expand significantly when heated, and the copper bellows 31 will push the plastic slider 32 to move under pressure; the movement of the plastic slider 32 drives the screw rod body 35. Since the screw rod body 35 is in threaded engagement with the ball screw nut 36, the movement of the screw rod body 35 can drive the ball screw nut 36 to rotate; after the ball screw nut 36 rotates, it drives the driving gear 38 to rotate, and the driving gear 38 drives the driven gear 39 to drive the driving threaded column 33 to rotate; after the driving threaded column 33 rotates, it drives the clamped composite part 1 to move to compensate for the warpage value. Through the module number and gear ratio of the driving gear 38 and the driven gear 39, the workpiece positioning device can maintain adaptive adjustment with micron-level accuracy under the working conditions of high temperature difference.

[0049] Equivalently, the components included in the "assembly", "mechanism", and "device" of the present disclosure can also be flexibly combined, that is, modular production can be carried out according to the actual situation and assembled modularly as an independent module; they can also be assembled separately to form a module in this device. The division of the above components in the present disclosure is only one embodiment for the convenience of reading, rather than a limitation on the protection scope of the present disclosure. As long as the above components are included and have the same function, it should be understood as an equivalent technical solution of the present disclosure.

[0050] In the description of the present disclosure, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present disclosure and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present disclosure.

[0051] In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include at least one of such features. In the description of the present disclosure, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0052] In this disclosure, unless otherwise clearly stipulated or defined, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components or the interaction relationship between two components, unless otherwise clearly defined. For those of ordinary skill in the art, the specific meanings of the above terms in this disclosure can be understood according to specific circumstances.

[0053] In this disclosure, unless otherwise clearly stipulated or defined, the first feature being "on" or "under" the second feature can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature can be that the first feature is directly above or obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature can be that the first feature is directly below or obliquely below the second feature, or merely indicates that the horizontal height of the first feature is less than that of the second feature.

[0054] It should be noted that when an element is referred to as being "fixed to", "arranged on", "secured to" or "mounted on" another element, it can be directly on the other element or there can also be an intermediate element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intermediate element at the same time. Further, when an element is considered to be "fixedly connected" to another element, the two can be fixed in a detachable connection manner or a non-detachable connection manner, such as socket connection, snap connection, integral molding fixation, welding, etc., which can be achieved in the traditional technology and will not be elaborated here.

[0055] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0056] The above embodiments only represent several implementation manners of this disclosure, and the description is relatively specific and detailed, but it cannot be thus understood as a limitation on the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the inventive concept of this disclosure, several modifications and improvements can still be made, and these all belong to the protection scope of this disclosure.

Claims

1. A workpiece positioning device for a servo punch, characterized in that: It includes a clamping composite part (1), a driving mechanism (2), a thermal deformation compensation mechanism (3) and a substrate (4). The substrate (4) is suitable for being fixedly installed on a punching press. A punching fixed die (41) suitable for placing a workpiece is installed on the substrate (4). There are two clamping composite parts (1). The two clamping composite parts (1) are respectively slidably arranged on both sides of the punching fixed die (41) to clamp or release the workpiece. The driving mechanism (2) is arranged on the substrate (4) and is connected to the two clamping composite parts (1) and is suitable for driving the two clamping composite parts (1) to move synchronously towards or away from each other. The thermal deformation compensation mechanism (3) is movably connected to the substrate (4). There are two groups of the thermal deformation compensation mechanisms (3). The two groups of the thermal deformation compensation mechanisms (3) respectively correspond to the two clamping composite parts (1) one by one. When one side of the clamping composite part (1) close to the workpiece is heated, the clamping composite part (1) will warp towards the side where the workpiece is located. At this time, the thermal deformation compensation mechanism (3) will drive the clamping composite part (1) to move away from the workpiece under the action of high temperature to compensate for the warping. The thermal deformation compensation mechanism (3) includes a copper bellows (31) and a plastic slider (32). An installation groove (14) is formed on the side of the clamping composite part (1) away from the punching fixed die (41). The installation groove (14) does not penetrate through the clamping composite part (1). One end of the copper bellows (31) is inserted into the installation groove (14) and fixedly connected to the bottom of the installation groove (14). The maximum outer diameter of the copper bellows (31) is equal to the groove diameter of the installation groove (14). The plastic slider (32) is slidably arranged on the side of the clamping composite part (1) away from the punching fixed die (41). One end of the copper bellows (31) away from the bottom of the installation groove (14) is fixedly connected to the plastic slider (32). A high-viscosity silicone oil is injected into the copper bellows (31). The high-viscosity silicone oil fills the entire copper bellows (31). When heated, the high-viscosity silicone oil expands and drives the copper bellows (31) to extend to push the plastic slider (32) to move.The thermal deformation compensation mechanism (3) further includes a driving threaded column (33) and a fixing block (34). The fixing block (34) is located on one side of the plastic slider (32). The plastic slider (32) and the clamping composite member (1) are adapted to move relative to the fixing block (34). One end of the driving threaded column (33) passes through the fixing block (34) and is threadedly connected to the fixing block (34). When the plastic slider (32) moves, it will drive the driving threaded column (33) to rotate and move relative to the fixing block (34). One end of the driving threaded column (33) is rotatably connected to the clamping composite member (1). A retaining piece (16) is fixedly installed on the side of the clamping composite member (1) connected to the driving threaded column (33). The retaining piece (16) is adapted to drive the clamping composite member (1) and the driving threaded column (33) to move synchronously relative to the fixing block (34). The thermal deformation compensation mechanism (3) further includes a lead screw body (35), a ball screw nut (36), and a fixing plate (37). The fixing plate (37) is fixedly provided on the side of the plastic slider (32) away from the clamping composite member (1). The ball screw nut (36) is rotatably connected to the fixing plate (37). One end of the lead screw body (35) is fixedly connected to the plastic slider (32), and the other end is inserted into the ball screw nut (36) and is in threaded cooperation with the ball screw nut (36). When the lead screw body (35) moves, it will drive the ball screw nut (36) to rotate, so as to drive the driving threaded column (33) to rotate. The thermal deformation compensation mechanism (3) further includes a driving gear (38) and a driven gear (39). The driving gear (38) is sleeved on the ball screw nut (36) and rotates synchronously with the ball screw nut (36). The driven gear (39) is sleeved on the driving threaded column (33) and rotates synchronously with the driving threaded column (33). The driving gear (38) is engaged with the driven gear (39).; 2. The workpiece positioning device for a servo press according to claim 1, characterized in that: The clamping composite part (1) includes a plurality of invar plates (11) and a plurality of aluminum alloy plates (12). After the plurality of invar plates (11) and the plurality of aluminum alloy plates (12) are alternately stacked in sequence, they are connected by rivets. The stacking direction of the plurality of invar plates (11) and the plurality of aluminum alloy plates (12) is the sliding direction of the clamping composite part (1). The sides of the clamping composite part (1) close to and away from the workpiece are both invar plates (11).

3. The workpiece positioning device for a servo press according to claim 2, characterized in that: The thickness ratio of the invar plate (11) to the aluminum alloy plate (12) is 3:

5.

4. The workpiece positioning device for a servo press according to claim 2, wherein: A sliding plate (43) is slidably connected to the substrate (4). The sliding plate (43) is connected to the driving mechanism (2). The clamping composite part (1) is arranged on the sliding plate (43). The clamping composite part (1) can slide synchronously with the sliding plate (43), and the clamping composite part (1) can move relative to the sliding plate (43) under the drive of the thermal deformation compensation mechanism (3).

5. The workpiece positioning device for a servo punch press according to claim 4, wherein: The clamping composite part (1) further includes a U-shaped plate (13). The plurality of invar plates (11) and the plurality of aluminum alloy plates (12) are all fixedly installed in the U-shaped plate (13). A small guide rail group (44) is arranged at the top of the sliding plate (43). The U-shaped plate (13) is connected to the small guide rail group (44) to be suitable for moving relative to the sliding plate (43).

6. The workpiece positioning device for a servo punch press according to claim 1, wherein: The thickness of the driven gear (39) is greater than the thickness of the driving gear (38); a rotating bearing is arranged on the fixing plate (37). The ball screw nut (36) is press-fitted into the rotating bearing. A lubricating grease is applied to the threaded connection between the driving threaded column (33) and the fixing block (34).

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