Workpiece positioning device for servo punching machine

Abstract

The invention relates to the field of punching machines, and discloses a workpiece positioning device for a servo punching machine. The device comprises two clamping composite parts, a driving mechanism, a thermal deformation compensation mechanism and a base plate, a stamping fixed die is installed on the base plate, the two clamping composite parts slide on the two sides of the stamping fixed die respectively to clamp or loosen a workpiece, and the driving mechanism is connected with the two clamping composite parts to drive the two clamping composite parts to move synchronously. Two groups of thermal deformation compensation mechanisms are arranged, and the two groups of thermal deformation compensation mechanisms are in one-to-one correspondence with the two clamping composite parts respectively; when the side, close to the workpiece, of the clamping composite part is warped, the thermal deformation compensation mechanism can drive the clamping composite part to move in the direction away from the workpiece under the action of high temperature so as to compensate warpage. After being heated, the thermal deformation compensation mechanism can drive the clamping composite part to move in the direction opposite to the warping direction so as to compensate the warping value generated by thermal deformation of the clamping composite part; the workpiece machining precision is improved; the service life of the workpiece positioning device is prolonged.

Description

Technical Field

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

[0002] Due to the high stability of servo punching presses, they are widely used in the stamping industry. To improve the stamping efficiency of servo punching presses for workpieces, a workpiece positioning device is usually provided on the punching press, and an automatic loading and unloading mechanism is provided on one side of the punching press. The workpiece is conveyed to the workpiece positioning device through the automatic loading and unloading mechanism. Then, the stamping mechanism on the punching press stamps the workpiece located on the workpiece positioning device, and the stamped workpiece is automatically unloaded from the workpiece positioning device through the automatic loading and unloading mechanism, so that the punching press 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 press, cutting heat and frictional heat will be generated. After the punching press 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 press, 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 press. 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, and there are two sets of the thermal deformation compensation mechanisms, and the two sets of the 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 to a high temperature, 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 the 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. After the plurality of invar plates and the plurality of aluminum alloy plates are stacked alternately in sequence, they are 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 the 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 all 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, and the high-viscosity silicone oil fills the entire copper bellows. At high temperatures, the high-viscosity silicone oil expands due to heat, driving the copper bellows to stretch 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 relative to the fixed block synchronously.

[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 disposed on a 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 post 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 post and rotates synchronously with the driving threaded post. 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 provided 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 post and the fixed 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 "heating with heat", the thermal deformation compensation mechanism can drive the clamping composite to move in the reverse direction of warping after being heated to compensate for the warping value of 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 copper bellows is filled with high-viscosity silicone oil inside, the volume of the high-viscosity silicone oil will expand significantly after being heated. The copper bellows will then push the plastic slider to move under pressure, and further drive the driving threaded post to rotate to drive the clamping composite to move in the reverse 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. However, the cooperation between the lead screw 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 relatively lighter than the metal material. Therefore, the copper bellows does not need to exert a large thrust on 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 part to limit the movement of the clamping composite part, the clamping composite part will not move when it is subjected to the axial force of the driving threaded column. Therefore, the clamping composite part can be driven to move and compensate by driving the threaded column with a small torque. When the driving threaded column is stationary, it can also improve the stability of limiting the movement of the clamping composite part. Brief Description of the Drawings

[0019] Figure 1 It is a structural diagram of the clamping composite part, 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 part, 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 part 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 part 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 when the clamping composite part in the embodiment of the present invention does not warp;

[0024] Figure 6 It is a schematic diagram of clamping a workpiece after the clamping composite part in the embodiment of the present invention warps.

[0025] Description of the reference numerals: 1. Clamping composite part; 11. Invar steel plate; 12. Aluminum alloy plate; 13. U-shaped plate; 14. Installation groove; 15. Miniature bearing; 16. Retaining plate; 2. Driving mechanism; 3. Thermal deformation compensation mechanism; 31. Copper bellows; 32. Plastic slider; 33. Driving threaded column; 34. Fixed block; 35. Lead screw 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 manners

[0026] To make the above objects, features and advantages of the present invention more obvious and understandable, the following further details the present application in conjunction with the appended Figures 1-6 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 a 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 stamping fixed die 41 is installed on the substrate 4. The workpiece to be stamped will be placed on the stamping fixed die 41 through an automatic loading and unloading mechanism. After the workpiece is stamped, it will be loaded and unloaded from the stamping 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 stamping 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 groups of thermal deformation compensation mechanisms 3 are provided. The two groups of thermal deformation compensation mechanisms 3 respectively correspond to the two clamping composite members 1 one by one. When the 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 protrude 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 stamping fixed die 41. However, both sides of the positioning groove close to the two clamping composite members 1 penetrate through the stamping 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 the 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 And 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 part 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. The Invar plate 11 has high stiffness. The Invar plates 11 are interspersed 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 complements the high strength of the Invar, 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. The clamping composite part 1 is fixedly connected to the lug plate by bolts.

[0034] Refer 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 part 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 places where the clamping composite part 1 contacts the external workpiece or other components have greater stiffness and are more stable, improving the service life of the clamping composite part 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 for better cooperation 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. 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 part 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 part 1 to move to compensate for the warping value by applying a smaller force to the clamping composite part 1.

[0037] Combined with Figure 2 Refer 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 fixing 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 fixing 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 fixing 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 fixing block 34 to drive the clamping composite 1 to move away from the stamping fixed die 41 for compensation.

[0038] Wherein, a small slider is further slidably provided on the small linear guide. The plastic slider 32 is connected to the other small slider by bolts, reducing the friction force when the plastic slider 32 slides; in addition, the plastic slider 32 is made of plastic material, making the plastic slider 32 lighter in weight. Therefore, only a small force is required to push the plastic slider 32 to move when the copper bellows 31 expands.

[0039] Combined Figure 2 Refer to Figure 3 With Figure 4 , an installation groove 14 is formed 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 bolts, so that when the clamping composite 1 is warped due to heat, the heat can be timely transferred to the copper bellows 31, enabling the copper bellows 31 to respond in a timely manner. 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 flange and bolts. 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 when the copper bellows 31 expands, it is not easy to expand radially, 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 and can slow down the pressure fluctuation during sudden temperature changes. 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, driving the copper bellows 31 to retract along the creases of the folds. Among them, both ends of the copper bellows 31 are sealed, making the high-viscosity silicone oil not easy to leak and making the copper bellows 31 expand and contract stably each time.

[0041] Combined with Figure 2 Refer to Figure 3 And Figure 4 As shown in, on one side of the clamping composite part 1 close to the driving threaded column 33, a bearing groove is provided, and a miniature bearing 15 is placed in the bearing groove. One end of the driving threaded column 33 is inserted into the miniature bearing 15 and welded to the miniature bearing 15, so that the driving threaded column 33 can be rotatably connected to the clamping composite part 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 miniature bearing 15, and the outer diameter of the retaining piece 16 is larger than the groove diameter of the bearing groove, so that when the driving threaded column 33 moves relative to the fixed block 34, it can drive the clamping composite part 1 to move synchronously.

[0042] Combined with Figure 2 Refer to Figure 3 And Figure 4 As shown in, 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 part 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 part 1 to move.

[0043] Among them, a through hole penetrating through itself is provided on one side of the fixed 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, making the frictional resistance of the ball screw nut 36 relatively small when rotating relative to the fixed plate 37. In addition, a lubricating grease is applied to the threaded connection between the driving threaded column 33 and the fixed block 34, making the resistance small when the driving threaded column 33 rotates. 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 part 1 to move.

[0044] Combined with Figure 2 Refer 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, fixed plates 37 and rotating bearings are respectively arranged at intervals on both sides of the fixed block 34, and the two driving gears 38 are meshed with the driven gear 39 respectively, thus making the force to drive the driving threaded column 33 to rotate smaller.

[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 between the driving gear 38 and the driven gear 39, the compensation distance of the clamping composite part 1 can be adjusted, so that the compensation distance and the warping degree of the clamping composite part 1 are more accurate.

[0046] Refer to Figure 5 With Figure 6 , when the clamping composite part 1 does not warp, the copper bellows 31 is in a contracted state. After the clamping composite part 1 warps, assuming the warping height of the clamping composite part 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 composite parts 1 always maintain appropriate clamping on the workpiece.

[0047] The implementation principle of a 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 arranged in an alternating and overlapping manner, and through the differential deformation mechanism of "heating with heat", the high expansion characteristic of the aluminum alloy plate 12 can be transformed into a compensation advantage. 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 part 1 have a long service life and low cost.

[0048] When the clamping composite 1 warps due to temperature rise, the volume of the high-viscosity silicone oil will expand significantly after being 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 fit 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 clamping composite 1 to move to compensate for the warpage value. Through the modulus and gear ratio of the driving gear 38 and the driven gear 39, the workpiece positioning device can maintain self-adaptive adjustment with micron-level accuracy under the working condition 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 specifying 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 defined and limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. 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 defined and limited, the first feature being "on" or "under" the second feature may 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 may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than 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 may be directly on the other element or there may also be an intermediate element. When an element is considered to "connect to" another element, it may 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 may 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 brevity of 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 their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the inventive concept of this disclosure, several deformations 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 press, characterized in that: The invention comprises a clamping composite part (1), a driving mechanism (2), a thermal deformation compensation mechanism (3) and a base plate (4), wherein the base plate (4) is suitable for being fixedly mounted on a punching machine, a stamping fixed die (41) suitable for placing a workpiece is mounted on the base plate (4), two clamping composite parts (1) are provided, and the two clamping composite parts (1) are respectively slidably arranged on both sides of the stamping fixed die (41) to clamp or release the workpiece, and the driving mechanism (2) is arranged on the base plate (4) and connected to the two clamping composite parts (1) to drive the two clamping composite parts (1) to move the workpiece. 1) synchronously move towards or away from each other, the thermal deformation compensation mechanism (3) is movably connected to the base plate (4), and the thermal deformation compensation mechanism (3) is provided with two groups, and the two groups of thermal deformation compensation mechanisms (3) correspond to the two clamping composite parts (1) respectively; when the side of the clamping composite part (1) close to the workpiece is subjected to high temperature, 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.

2. The workpiece positioning device for a servo punch press according to claim 1, characterized in that: The clamping composite component (1) comprises a plurality of Invar steel plates (11) and a plurality of aluminum alloy plates (12); the plurality of Invar steel plates (11) and the plurality of aluminum alloy plates (12) are stacked alternately in sequence and then connected by rivets; the stacking direction of the plurality of Invar steel plates (11) and the plurality of aluminum alloy plates (12) is the sliding direction of the clamping composite component (1); the side of the clamping composite component (1) close to the workpiece and the side away from the workpiece are both the Invar steel plates (11).

3. The workpiece positioning device for a servo punch 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 punch press according to claim 2, characterized in that: A sliding plate (43) is slidably connected to the base plate (4), the sliding plate (43) is connected to the driving mechanism (2), the clamping composite component (1) is arranged on the sliding plate (43), the clamping composite component (1) can slide synchronously with the sliding plate (43), and the clamping composite component (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, characterized in that: The clamping composite (1) also includes a U-shaped plate (13), and the plurality of Invar plates (11) and the plurality of aluminum alloy plates (12) are fixedly installed in the U-shaped plate (13). A small guide rail group (44) is provided on the top of the sliding plate (43), and the U-shaped plate (13) is connected to the small guide rail group (44) so ​​as 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, characterized in that: The thermal deformation compensation mechanism (3) comprises a copper bellows (31) and a plastic slider (32); a mounting groove (14) is provided on a side of the clamping composite part (1) away from the stamping fixed die (41); the mounting groove (14) does not penetrate the clamping composite part (1); one end of the copper bellows (31) is inserted into the mounting groove (14) and fixedly connected to the bottom of the mounting groove (14); the maximum outer diameter of the copper bellows (31) is equal to the groove diameter of the mounting groove (14); The plastic slider (32) is slidably arranged on a side of the clamping composite part (1) away from the stamping fixed die (41); one end of the copper bellows (31) away from the bottom of the mounting groove (14) is fixedly connected to the plastic slider (32); high-viscosity silicone oil is injected into the copper bellows (31), and the high-viscosity silicone oil fills the entire copper bellows (31); at high temperatures, the high-viscosity silicone oil expands due to the heat, driving the copper bellows (31) to stretch so as to push the plastic slider (32) to move.

7. The workpiece positioning device for a servo punch press according to claim 6, characterized in that: The thermal deformation compensation mechanism (3) also includes a driving threaded column (33) and a fixed block (34). The fixed block (34) is located on one side of the plastic slider (32). The plastic slider (32) and the clamping composite component (1) are suitable for moving relative to the fixed block (34). One end of the driving threaded column (33) passes through the fixed block (34) and is threadedly connected to the fixed block (34). The movement of the plastic slider (32) will drive the driving threaded column (33) to rotate and move relative to the fixed block (34). One end of the driving threaded column (33) is rotatably connected to the clamping composite component (1). A baffle (16) is fixedly installed on one side of the clamping composite component (1) where the driving threaded column (33) is connected. The baffle (16) is suitable for driving the clamping composite component (1) and the driving threaded column (33) to move synchronously relative to the fixed block (34).

8. The workpiece positioning device for a servo punch press according to claim 7, characterized in that: The thermal deformation compensation mechanism (3) also includes a screw body (35), a ball screw nut (36) and a fixing plate (37). The fixing plate (37) is fixedly arranged on a side of the plastic slider (32) away from the clamping composite component (1). The ball screw nut (36) is rotatably connected to the fixing plate (37). One end of the screw body (35) is fixedly connected to the plastic slider (32), and the other end is inserted into the ball screw nut (36) and threadedly matched with the ball screw nut (36). When the screw body (35) moves, it drives the ball screw nut (36) to rotate, thereby driving the driving thread column (33) to rotate.

9. The workpiece positioning device for a servo punch press according to claim 8, characterized in that: The thermal deformation compensation mechanism (3) further comprises 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 meshed with the driven gear (39).

10. The workpiece positioning device for a servo punch press according to claim 9, characterized in that: The thickness of the driven gear (39) is greater than that of the driving gear (38); a rotating bearing is provided on the fixing plate (37), the ball screw nut (36) is interference-inserted in the rotating bearing, and grease is applied to the threaded connection between the driving thread column (33) and the fixing block (34).

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