Overhead crane transport method and overhead crane transport system

Abstract

The present invention discloses a crane handling method and a crane handling system, wherein the crane includes a detection mechanism, and the detection mechanism can generate a first signal, a second signal, and a third signal. The handling method includes a step of placing a wafer box, and the step of placing the wafer box includes: a lifting device lowers the wafer box located at a transmission position by a first preset distance, and judges whether the second signal is not detected in this process; if so, after the wafer box is lowered by the first preset distance, judges whether the second signal is detected and the first signal is not detected; if so, a pair of clamps move oppositely in the horizontal direction by a second preset distance; judges whether the third signal is detected; if not, a gripping device moves upward by a third preset distance, and judges whether the first signal, the second signal, and the third signal are not detected in this process; if so, lifts the gripping device to the transmission position. The present invention can avoid smashing the wafer box, causing the wafer box to fall due to manual operation, and the wafer box tilting and falling when clamping.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer processing equipment, and in particular to an overhead crane transporting method and an overhead crane transporting system. Background Art

[0002] The automatic material handling system (AMHS) is also called the overhead crane system. The AMHS is mainly composed of tracks, an overhead crane (OHT) and a control system. The AMHS is widely used in semiconductor wafer factories. It can accurately and quickly transport wafer boxes to destinations such as process machines. When the overhead crane takes the wafer box, the clamp may drop too far and interfere with the wafer box, or the manual operation may accidentally trigger the clamp to open and cause the wafer box to fall, or the wafer box may tilt when clamping. If these situations are not discovered in time, they will cause damage to the wafer and affect the handling of the wafer box. Summary of the invention

[0003] In order to overcome the above-mentioned shortcomings, the purpose of the present invention is to provide an overhead crane transport method and an overhead crane transport system, which can prevent the grasping device from hitting the wafer box when placing the wafer box, the manual operation from accidentally triggering the clamp to open and causing the wafer box to fall, and the wafer box to tilt and fall when clamped, so that the wafer box can be accurately placed on the process table during the transmission process.

[0004] In order to achieve the above purpose, the technical solution adopted by the present invention is: a method for handling by an overhead crane, the overhead crane includes a grabbing device that can be raised and lowered under the drive of a lifting device, and the grabbing device includes:

[0005] A clamping mechanism, the clamping mechanism comprising a mounting plate and a pair of clamping jaws, the pair of clamping jaws being movable relative to the mounting plate to clamp or release the wafer box;

[0006] A trigger mechanism, the trigger mechanism includes a lifting assembly disposed on the mounting plate, the lifting assembly being slidably connected to the mounting plate, the lifting assembly being able to abut against the wafer box and move up and down along the thickness direction of the mounting plate;

[0007] The detection mechanism includes a lifting detection component and a clamping detection component. The lifting detection component is used to detect the height of the lifting component when it is pushed by the wafer box. When the clamp is at the highest position that can clamp the wafer box, a second signal is generated. When the clamp is at the lowest position that can clamp the wafer box, a first signal is generated. The clamping detection component is used to detect the position of the clamp in translation. When the clamp is at the clamping position, the clamping detection component generates a third signal.

[0008] The transport method includes a wafer box placement step, and the wafer box placement step includes:

[0009] The lifting device lowers the wafer box to a first preset distance suitable for receiving the wafer box, and determines whether a second signal is detected during the process;

[0010] If not, after the wafer box descends the first preset distance, it is determined whether the detection result of the first signal and the second signal is a first preset result, and the first preset result is that the second signal is detected and the first signal is not detected;

[0011] If yes, the pair of clamping jaws move away from each other in the horizontal direction by a second preset distance;

[0012] determining whether a third signal is detected;

[0013] If not, the gripping device moves upward by a third preset distance to raise the supporting surface of the clamping claw above the supported surface of the wafer box, and in this process, determines whether the detection results of the first signal, the second signal and the third signal are the second preset results, and the second preset result is that the first signal, the second signal and the third signal are not detected;

[0014] If so, the gripping device is raised to its initial position before lowering.

[0015] Specifically, the transport method includes a wafer box taking step, and the wafer box taking step includes:

[0016] The gripping device moves downward to a fourth preset distance suitable for clamping the wafer box;

[0017] Determining whether a detection result of the first signal and the second signal is a first preset result;

[0018] If yes, the pair of clamping jaws move relatively in the horizontal direction by a fifth preset distance;

[0019] determining whether a third signal is detected;

[0020] If yes, the gripping device moves upward by a sixth preset distance suitable for eliminating the gap between the wafer box and the clamping claw, and determines whether the detection result of the first signal, the second signal and the third signal is a third preset result, and the third preset result is that the second signal and the first signal are not detected and the third signal is detected at the same time;

[0021] If so, the gripper lifts the wafer box to the transfer position and carries it.

[0022] Furthermore, during the process of the gripping device moving down the fourth preset distance, the step of taking the wafer box also includes:

[0023] It is determined whether the first signal is detected. If so, the grasping device stops moving downward. If not, the grasping device moves downward until it reaches a fourth preset distance.

[0024] Further, the lifting detection assembly includes a first sensor group and a second sensor group fixed on the mounting plate, the first sensor group and the second sensor group are arranged in an up-down direction at intervals and respectively have a first light beam and a second light beam extending in a horizontal direction, and the first light beam and the second light beam generate a first signal and a second signal respectively when blocked by the lifting assembly;

[0025] The clamping detection component includes two third sensor groups respectively fixed on a pair of clamping claws. The two third sensor groups respectively have two third light beams extending in the vertical direction. When the two third light beams are simultaneously blocked by the clamping part of the wafer box, a third signal is generated.

[0026] Furthermore, the detection mechanism also includes a tilt detection component, which includes a fourth sensor group respectively fixed on a pair of clamps, and the fourth sensor group has a fourth light extending in the horizontal direction. When the wafer box tilts around a horizontal axis orthogonal to the fourth light, the fourth light is blocked by the wafer box and a fourth signal is generated.

[0027] Further, the tilt detection component also includes a fifth sensor group and a sixth sensor group respectively fixed on a pair of clamps, the fifth sensor group and the sixth sensor group respectively have a fifth light ray and a sixth light ray parallel to the fourth light ray, the fourth light ray is close to the middle of the clamping part of the wafer box, the fifth light ray and the sixth light ray are arranged at intervals on both sides of the fourth light ray, and when the wafer box tilts around a horizontal axis parallel to the fourth light ray, at least one of the fifth light ray and the sixth light ray is turned on and generates a fifth signal.

[0028] Furthermore, after the step of moving the gripping device upward by the third preset distance, or after the step of moving the gripping device upward by the sixth preset distance, the following steps are also included:

[0029] Determine whether the first signal, the fourth signal and the fifth signal are detected. If the fourth signal is detected, a first alarm signal is issued. If the fifth signal is detected, a second alarm signal is issued. If the fourth signal and the fifth signal are not detected but the first signal is detected, a third alarm signal is issued.

[0030] Furthermore, the step of moving the gripping device upward by a sixth preset distance further includes the following steps:

[0031] During this process, it is determined whether the pulling force applied to the lifting device exceeds the threshold value. If so, the grasping device stops moving upward. If not, after the grasping device moves upward a sixth preset distance, it is determined whether the detection results of the first signal, the second signal and the third signal are the third preset results.

[0032] Furthermore, the lifting assembly includes a top pressure piece and a moving piece. The moving piece and the top pressure piece are connected by an adjusting piece and the distance between them can be adjusted by the adjusting piece. The top pressure piece can abut against the wafer box, and the moving piece passes through the mounting plate.

[0033] The invention also discloses an overhead crane handling system, the system comprises an overhead crane, the overhead crane comprises a grabbing device and a lifting device, and the overhead crane adopts the above-mentioned handling method. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A flowchart of the steps of taking a wafer box in an embodiment of the present invention;

[0035] Figure 2 A flowchart of the steps of placing a wafer box in an embodiment of the present invention;

[0036] Figure 3 It is a schematic diagram of the three-dimensional structure of the grasping device grasping the wafer box in the embodiment of the present invention;

[0037] Figure 4 for Figure 3 Enlarged view of point A in the middle;

[0038] Figure 5 is a cross-sectional view of a grasping device grasping a wafer box in an embodiment of the present invention;

[0039] Figure 6 It is a schematic diagram of the structure in which the third sensor group to the sixth sensor group are connected to the clamping claw in an embodiment of the present invention;

[0040] Figure 7 is a schematic diagram of the positions of the wafer box and the gripping device when the wafer box is not tilted in an embodiment of the present invention;

[0041] Figure 8 is a schematic diagram of the positions of the wafer box and the gripping device when the wafer box is tilted about a horizontal axis orthogonal to the fourth light ray in an embodiment of the present invention;

[0042] Fig. 9 A schematic structural diagram of a wafer box in an embodiment of the present invention. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more definite definition of the protection scope of the present invention.

[0044] According to an embodiment of the present invention, an overhead crane is used for clamping and transporting a wafer box 9. The overhead crane can move along a track to move above different process tables. The overhead crane includes a lifting device and a gripping device. The gripping device and the lifting device are fixedly connected and can be raised and lowered under the drive of the lifting device. The gripping device includes a clamping mechanism, a triggering mechanism, and a detection mechanism.

[0045] See attached Figure 3 and attached Figure 5 As shown, the clamping mechanism includes a mounting plate 1 and a pair of jaws 2. The pair of jaws 2 can move relative to the mounting plate 1 to clamp or release the wafer box 9. The pair of jaws 2 move relative to or away from each other under the drive of the clamping drive member. When the pair of jaws 2 move relative to each other, they can clamp the wafer box 9. The wafer box 9 includes a clamping portion 91, and the clamping portion 91 is clamped in a clamping cavity formed by the clamping portion 2 and the mounting plate 1. When the lower end surface of the clamping portion 91 abuts against the supporting surface of the jaws 2, the jaws 2 can drive the wafer box 9 to rise and fall. When the pair of jaws 2 move away from each other, they can detach from the clamping portion 91 of the wafer box 9 and release the wafer box 9. At this time, the projections of the clamping portion 91 and the jaws 2 in the same horizontal plane need not overlap, and the jaws 2 will not interfere with the wafer box 9 when they are raised or lowered. See attached Fig. 9 As shown, the clamping portion 91 is a T-shaped structure.

[0046] The trigger mechanism includes a lifting assembly 3 disposed on the mounting plate 1, the lifting assembly 3 is slidably connected to the mounting plate 1, and the lifting assembly 3 can abut against the wafer box 9 and move up and down along the mounting plate 1. The lifting assembly 3 falls under the action of its own gravity, and when the lifting assembly 3 abuts against the wafer box 9, it can move up relative to the mounting plate 1 under the limit of the wafer box 9.

[0047] The detection mechanism includes a lifting detection component, which is used to detect the lifting height of the lifting component 3 and can generate a first signal and a second signal. When the first signal is generated, the lifting height of the lifting component 3 is greater than the lifting height of the lifting component 3 when the second signal is generated. That is, when the lifting component 3 moves up to the first height position relative to the mounting plate 1, the first signal can be generated, and the clamp is at the lowest position that can hold the wafer box; when it moves up to the second height position, the second signal can be generated, and the clamp is at the highest position that can hold the wafer box, and the first height position is higher than the second height position.

[0048] The lifting detection component determines the lifting height of the entire clamping device through the first signal and the second signal. When the gripping device grabs the wafer box 9 and separates the wafer box 9 from the process table, the lifting detection component should not detect the first signal and the second signal. When the gripping device is in the process of grabbing the wafer box 9 on the process table, the lifting detection component should detect the second signal and not the first signal.

[0049] The detection mechanism also includes a clamping detection component, which is used to detect the position of the clamping jaw 2. When the clamping jaw 2 is located at the clamping position for clamping the wafer box 9, the clamping detection component generates a third signal. The presence or absence of the third signal is used to determine whether the clamping jaw 2 has moved to the clamping position and is ready to clamp the wafer box 9.

[0050] The transport method also includes a step of placing a wafer box. After the crane moves along the track to be directly above the process table where the wafer box 9 is to be placed, the wafer box 9 needs to be placed from the transfer position to the process table.

[0051] See attached Figure 2 As shown, the steps of placing the wafer box include:

[0052] S1 . A lifting device lowers a wafer box 9 located at a transfer position by a first preset distance.

[0053] The first preset distance can be set according to the height position of the process table. After the wafer box 9 is lowered by the first preset distance, it should be lowered to the preset height for placing the wafer box 9.

[0054] S2, determining whether the second signal is not detected during the process in which the wafer box 9 located at the transfer position descends the first preset distance.

[0055] In this process, the second signal should not be detected, that is, the wafer box 9 does not abut against any process table or other wafer boxes 9 in advance. When the overhead crane mistakenly places the wafer box 9 on a process table where there is already a wafer box 9, the wafer boxes 9 will be stacked without buffering, causing the wafer box 9 to be smashed. It is ensured that the second signal is not detected during the process of the wafer box 9 descending the first preset distance, which effectively avoids the stacking of the wafer boxes 9 and the smashing of the wafer boxes 9.

[0056] S3 , if yes, determine whether the detection result of the first signal and the second signal after the wafer box 9 descends the first preset distance is the first preset result.

[0057] The first preset result is that the second signal is detected and the first signal is not detected. At this time, the wafer box 9 is placed on the process table, the clamping claw 2 is in the clamping position but is separated from the clamping part 91 in the vertical direction, and the lifting assembly 3 moves up relative to the mounting plate 1 under the push of the wafer box 9, but can only trigger the second signal.

[0058] Since the wafer box 9 may not be in contact with the process table and is not lifted, the wafer box 9 may fall after being released by the clamp 2. Therefore, it is necessary to ensure that the second signal is detected and the first signal is not detected after the wafer drops the first preset distance, thereby avoiding the possibility of the wafer falling.

[0059] S4: If yes, the pair of clamping jaws 2 move away from each other in the horizontal direction by a second preset distance.

[0060] At this time, the clamping jaw 2 is in an open state, and the projections of the clamping jaw 2 and the clamping portion 91 on the same horizontal plane should not overlap.

[0061] S5. Determine whether a third signal is detected.

[0062] The third signal is used to determine whether the clamp 2 is already in the open state. Only when there is no third signal, the clamp 2 will not interfere with the wafer box 9 during its ascent.

[0063] S6: If not, the grabbing device moves upwards a third preset distance.

[0064] S7. Determine whether the detection results of the first signal, the second signal, and the third signal are the second preset results when the grasping device moves upward by the third preset distance.

[0065] The second preset result is that the first signal, the second signal, and the third signal are not detected.

[0066] When the gripping device moves the third preset distance, the speed is slow and the moving distance is short. Although the third signal is not detected, the clamping claw 2 may scrape the edge of the clamping portion 91. During this process, the gripping device slowly moves upward to ensure that the gripping device is safely separated from the clamping portion 91 after moving the third preset distance. At this time, the second preset result is met. Exemplarily, the third preset distance is 10 mm.

[0067] S8. If yes, lift the grabbing device to the transfer position.

[0068] At this time, the gripping device has been completely separated from the clamping portion 91, and the gripping device can be quickly lifted to the transfer position, and continue to move on the track to the next position for taking the wafer box 9. At this point, the transportation of one wafer box 9 is completed.

[0069] In one embodiment, when the wafer box 9 at the transfer position descends the first preset distance, if the second signal is detected, an alarm is triggered and the overhead crane stops moving.

[0070] At this time, only the second signal is detected or the first signal and the second signal are detected at the same time. When the gripping device is not lowered by the first preset distance, the second signal has been detected, and at this time, the process table where the wafer box 9 is placed may already have a wafer box 9. If the gripping device continues to descend, the gripping device may hit the wafer box 9. Stopping the descent can prevent the gripper 2 from colliding with the wafer box 9.

[0071] When there is no wafer box under the wafer box, the descending distance calculated by the encoder in the lifting device is less than the actual descending distance, that is, the actual descent is to a position lower than the preset position for placing the wafer box 9. At this time, the wafer box 9 may collide with the process table. Stopping the descent can prevent the clamp 2 from colliding with the wafer box 9.

[0072] In one embodiment, after the wafer box 9 descends the first preset distance, if the detection result of the first signal and the second signal is not the first preset result, an alarm is issued and the overhead crane stops moving.

[0073] At this time, if there is no first signal and the second signal, there may be no process table for placing the wafer box 9, and the wafer box 9 is not against the placement table, so an alarm is issued and the next step is stopped to prevent the wafer box 9 from falling.

[0074] In one embodiment, when the pair of clamping jaws 2 still detect the third signal after moving away from each other by the second preset distance, and the clamping portion 91 of the wafer box 9 is still in the clamping jaws 2, an alarm is sounded and the overhead crane stops moving.

[0075] In one embodiment, when the gripping device moves upward by a third preset distance, if the detection results of the first signal, the second signal and the third signal are not the second preset results, the overhead crane stops and alarms. At this time, there may be a second signal because there is an abnormality in the position of the clamping portion 91 and the clamping claw 2 of the wafer box 9, for example, a clamping claw 2 scrapes the edge of the clamping portion 91, causing the wafer box 9 to deflect. If the lifting continues, the clamping claw 2 will suddenly separate from the edge of the clamping portion 91, causing the wafer box 9 to shake and the wafer to be damaged due to vibration.

[0076] In this embodiment, through steps S1-S8, a wafer box 9 can be stably placed, meeting the need for accurate placement of the wafer box 9. In this process, by detecting the second signal during the first preset distance when the lifting device descends, the situation in which the grasping device hits the wafer box 9 when the wafer box 9 is stacked is avoided. Through the first preset result, it is avoided that the wafer box 9 is not placed on the process table or the clamp is opened incorrectly due to misoperation by personnel, causing the wafer box 9 to fall. Then, through the second preset result, it is ensured that the grasping device and the wafer box 9 are completely separated before they can be reset, avoiding the scratches between the clamp 2 and the wafer box 9 causing the wafer box 9 to tilt and fall. Each step of the placement step is strictly monitored, and even if the process table does not have a sensor that interacts with the overhead crane or the sensor is abnormal, it can ensure that the wafer box 9 is accurately placed on the process table.

[0077] The handling method includes the steps of taking out the wafer box, see the attached Figure 1 As shown, the steps of taking the wafer box include:

[0078] S9, the grasping device moves downward a fourth preset distance.

[0079] The fourth preset distance is preset and can be changed according to the type of wafer box 9 and process table. When the gripping device just moves down the fourth preset distance, the clamping mechanism should just reach the position where the wafer box 9 can be clamped from the transfer position, and the transfer position is the height position of the overhead traveling device along the track.

[0080] At this time, the clamping jaws 2 are in an open state, and the projections of the supporting surfaces of the clamping jaws 2 and the clamping portion 91 in the same horizontal plane do not overlap. When the two clamping jaws 2 move downward, the two supporting surfaces move downward from both sides of the clamping portion 91.

[0081] S10: Determine whether the detection result of the first signal and the second signal is a first preset result.

[0082] The first preset result is that the second signal is detected and the first signal is not detected.

[0083] After the grasping device moves down the fourth preset distance, the first signal and the second signal are used to determine whether the grasping device has moved down the specified distance. When there is the second signal and no first signal, it indicates that the grasping device has just moved down the fourth preset distance and the position reached has a wafer box 9, the trigger mechanism abuts against the wafer box 9, and moves up to the second height position.

[0084] S11: If yes, the pair of clamping jaws 2 move relatively in the horizontal direction by a fifth preset distance.

[0085] If the clamping jaw 2 moves the fifth preset distance, the clamping jaw 2 should reach the clamping position, at which time the bearing of the clamping jaw 2 and the clamping part 91 in a horizontal plane partially overlap, but the supporting surface of the clamping jaw 2 is located below the clamping part 91 of the wafer box 9, and the clamping jaw 2 does not abut against the clamping part 91. The clamping jaw 2 can abut against the clamping part 91 after moving up a distance to drive the wafer box 9 to move up and down synchronously. The fifth preset distance is set in advance and can be changed according to the specifications of the wafer box 9. The fifth preset distance can be equal to the second preset distance.

[0086] S12: Determine whether a third signal is detected.

[0087] After the clamping jaw 2 moves the fifth preset distance, when the third signal is detected, it indicates that the clamping portion 91 is already in the clamping cavity, and the clamping device moves upward, and can abut against the clamping portion 91 to drive the wafer box 9 to continue to move upward. The clamping jaw 2 is in a clamping state at this time, and the projections of the supporting surface of the clamping jaw 2 and the clamping portion 91 in the same horizontal plane overlap, but there is a gap between the supporting surface and the clamping portion 91 in the vertical direction.

[0088] S13: If yes, the grabbing device moves upward by a sixth preset distance.

[0089] The sixth preset distance is usually small, so as to judge whether there is any abnormality such as relative deviation between the positions of the wafer box 9 and the clamping claw 2 during this process. Exemplarily, the sixth preset distance is 10 mm. At the same time, the speed of the gripping device moving upward by the sixth preset distance is relatively slow, so as to ensure that even if there is a deviation of the wafer box 9, it can be discovered and stopped in time to reduce the damage to the wafers in the wafer box 9. The sixth preset distance can be equal to the third preset distance.

[0090] S14, determining whether the pulling force applied to the lifting device exceeds a threshold value during the process in which the grasping device moves upward by a sixth preset distance.

[0091] If the lifting device is within the allowable force range, the lifting device can normally lift the gripping device to move the sixth preset distance, thereby preventing the wafer box 9 from being pulled and damaged due to overload of the lifting device when the wafer box 9 is not separated from the process machine.

[0092] S15: If not, determine whether the detection results of the first signal, the second signal and the third signal after the grasping device moves upward by a sixth preset distance are the third preset results.

[0093] The third preset result is that the third signal is detected while the second signal and the first signal are not detected.

[0094] When the grasping device moves upward the sixth preset distance, the distance between the supporting surface of the clamp 2 and the lower surface of the clamping part 91 is eliminated, the wafer box 9 is slightly lifted by the grasping device, and the wafer box 9 is separated from the process table. At this time, the lifting assembly 3 should fall naturally, satisfying the third preset result.

[0095] S16: If yes, the gripping device lifts the wafer box 9 to the transfer position and carries it.

[0096] In this process, the speed at which the grasping device moves upward is greater than the speed at which the grasping device moves upward the sixth preset distance in step S13, because the wafer box 9 has been stably clamped at this time and the wafer box 9 is not tilted, so the wafer box 9 can be quickly lifted to the transfer position, and then the overhead crane moves along the track at the transfer position to transport the wafer box 9.

[0097] Through steps S9-S16, the wafer box 9 on a process table can be grasped, meeting the precise transportation requirements of the wafer box 9. In this process, by comparing with the first preset result, it is ensured that when the grasping device moves down the first preset distance, it can just drop to the specified position, and the lifting assembly 3 and the wafer box 9 are in abutment, that is, there is a wafer box 9 on the process table waiting to be grasped. Then, by the presence or absence of the third signal, it can be timely judged whether the clamp 2 moves to the grasping position. Then the grasping device moves upward by the sixth preset distance, and the pulling force on the lifting device is monitored in real time to ensure that the lifting device can lift the grasping device. By comparing with the third preset result, it is ensured that after the grasping device moves upward by the sixth preset distance, there is no abnormality in the position of the wafer box 9 and the clamp 2, so as to avoid the wafer box 9 being transported in an inclined state.

[0098] In the related art, a sensor is usually set on the process table, and the sensor interacts with the overhead crane to inform the overhead crane whether there is a wafer box 9 on the process table. However, in this embodiment, even if there is no sensor on the process table or the sensor is abnormal, the first signal and the second signal on the overhead crane can be used to understand the situation of the wafer box 9 on the process table. In the related art, when the clamp 2 is clamping the wafer box 9, when the wafer box 9 is slightly tilted, the overhead crane cannot detect it in time. However, in this embodiment, by first moving the grasping device upward by a smaller fourth preset distance, and combining the second signal and the third signal, the problem of relative deviation between the wafer box 9 and the clamp 2 in the initial stage of grasping the wafer box 9 can be discovered in time.

[0099] In one embodiment, during the process of the grasping device moving down the fourth preset distance, the wafer box taking step also includes: determining whether the first signal is detected, if so, an alarm is given and the overhead crane stops moving, and the grasping device stops moving down; if not, the grasping device moves down until it reaches the fourth preset distance.

[0100] During the process of the grasping device moving down the fourth preset distance, it has not reached the fourth preset distance and a first signal is detected, which means that the distance calculated by the encoder of the lifting mechanism is smaller than the actual descent distance. When the first signal is detected, the grasping device stops moving down to avoid the grasping device smashing the wafer box.

[0101] In one embodiment, after the gripping device moves down a fourth preset distance, if the detection result of the first signal and the second signal is not the first preset result, an alarm is given and the overhead travelling crane stops moving. At this time, the second signal is not detected or the first signal and the second signal are detected at the same time.

[0102] After the grasping device descends the fourth preset distance, if the second signal is not detected, it means that the lifting assembly 3 is not against the wafer box 9. For example, there is no wafer box 9 on the process table or there is no process table under the grasping device. At this time, the grasping device does not need to grasp the wafer box 9, and an alarm is issued and the next step is stopped.

[0103] After the grasping device descends the fourth preset distance, if the first signal and the second signal are detected at the same time, the descent distance calculated by the encoder in the lifting device is less than the actual descent distance, that is, the actual descent distance is greater than the fourth preset distance, and the grasping device descends to a lower position, so an alarm is issued and the next action is stopped, which can avoid the grasping device smashing the wafer box.

[0104] In one embodiment, after the clamp 2 moves the fifth preset distance, if the third signal is not detected, an alarm is triggered and the overhead travelling crane stops moving. At this time, the clamp 2 has not moved to the clamping position, that is, the clamp 2 cannot clamp the clamping portion 91. At this time, the clamp 2 continues to move upward, and the wafer box 9 does not move upward synchronously or the wafer box 9 is offset, so an alarm is triggered and the next step of the action is stopped.

[0105] In one embodiment, when the pulling force on the lifting device exceeds a threshold, an alarm is sounded and the overhead crane stops moving. At this time, the wafer box 9 is not separated from the process table. If the lifting device lifts the gripping device overloaded, it may cause the gripping device to fall. Therefore, the lifting device stops lifting the gripping device and sounds an alarm.

[0106] In one embodiment, after the grabbing device moves upward by a sixth preset distance, if the detection results of the first signal, the second signal and the third signal are not the third preset results, an alarm is sounded and the overhead crane stops moving.

[0107] At this time, the gap between the supporting surface of the clamping jaw 2 and the lower surface of the clamping portion 91 is eliminated, and the wafer box 9 is slightly lifted by the gripping device. However, if there is an abnormality in the position of the clamping portion 91 and the clamping jaw 2, a second signal may be detected at this time. For example, the clamping portion 91 and the clamping jaw 2 are relatively deflected, causing the lifting assembly 3 to move upward relative to the mounting plate 1, so the second signal is detected.

[0108] In this embodiment, the steps of taking out the wafer box 9 and placing the wafer box 9 are repeated to realize the transportation of multiple wafer boxes 9 .

[0109] See attached Figure 4 As shown, the lifting detection assembly includes a first sensor group 5 and a second sensor group 6 fixed on the mounting plate 1. The first sensor group 5 and the second sensor group 6 are spaced apart in the up and down directions and respectively have a first light 51 and a second light 61 extending in the horizontal direction. When the first light 51 and the second light 61 are blocked by the lifting assembly 3, a first signal and a second signal are generated respectively.

[0110] The first sensor group 5 and the second sensor group 6 are respectively fixed on the upper surface of the mounting plate 1 through the first mounting seat 52 and the second mounting seat 62. Exemplarily, the first sensor group 5 and the second sensor group 6 are both through-beam sensors, including a transmitting end and a receiving end, and the through-beam light between the transmitting end and the receiving end is the first light 51 or the second light 61.

[0111] See attached Figure 5 As shown, the clamping detection component includes two third sensor groups 7 respectively fixed on a pair of clamps 2. The two third sensor groups 7 respectively have third light rays 71 extending in the vertical direction on the pair of clamps 2. When the two third light rays 71 are blocked by the wafer box 9 at the same time, a third signal is generated, indicating that the clamps 2 have moved to a position where they can clamp the wafer box 9.

[0112] Two third mounting seats 72 are fixed on the two clamping jaws 2, and two third sensor groups 7 are fixed on the third mounting seats 72 corresponding to the two clamping jaws 2. The third sensor group 7 is also a through-beam sensor. When a pair of clamping jaws 2 are symmetrically arranged relative to the lifting assembly 3, and the two third light beams 71 are also symmetrically arranged relative to the lifting assembly 3.

[0113] Because the two third sensor groups 7 are not installed at the edge of the clamping jaws 2 close to the clamping portion 91, it is impossible to determine that the clamping jaws 2 and the clamping portion 91 have been completely separated only by the third signal, that is, even without the third signal, the projections of the clamping jaws 2 and the clamping portion 91 on the same horizontal plane may still overlap, and at this time, the clamping jaws 2 will scratch the clamping portion 91 when they are raised and lowered, causing the wafer box 9 to shake. Therefore, in this embodiment, the third signal is combined with the second signal to determine whether the positions of the clamping portion 91 and the clamping jaws 2 are moved to avoid the deflection of the wafer box 9.

[0114] In one embodiment, see the attached Figure 6 As shown, the tilt detection assembly also includes a fourth sensor group 81 respectively fixed on a pair of clamps, the fourth sensor group has a fourth light 811 extending in the horizontal direction, when the wafer box tilts around a horizontal axis orthogonal to the fourth light, the fourth light is blocked by the wafer box and a fourth signal is generated.

[0115] The two opposing sensors of the fourth sensor group 81 are respectively arranged on the two clamping claws 2, one of the two opposing sensors emits a fourth light 811, and the other sensor receives the fourth light 811. When the wafer box 9 is in a normal state, the fourth light 811 of the fourth sensor group 81 is turned on. Figure 7 As shown, when the wafer box 9 is tilted around the horizontal axis orthogonal to the fourth light 811, as shown in Figure 8 As shown, the fourth light 811 is blocked by the wafer box 9 and generates a fourth signal. After the fourth signal is obtained, it means that the wafer box 9 is tilted around a horizontal axis orthogonal to the fourth light 811.

[0116] In one embodiment, the tilt detection component also includes a fifth sensor group 82 and a sixth sensor group 83 respectively fixed on a pair of clamps 2, the fifth sensor group 82 and the sixth sensor group 83 respectively have a fifth light ray 821 and a sixth light ray 831 parallel to the fourth light ray 811, the fourth light ray 811 is close to the middle of the clamping portion 91 of the wafer box 9, the fifth light ray 821 and the sixth light ray 831 are arranged at intervals on both sides of the fourth light ray 811, and when the wafer box 9 tilts around a horizontal axis parallel to the fourth light ray 811, at least one of the fifth light ray 821 and the sixth light ray 831 is turned on and generates a fifth signal.

[0117] When the wafer box 9 is in a normal state, Figure 7As shown, the fifth light 821 and the sixth light 831 are blocked by the adjacent protrusions 92 of the clamping portion of the clamping claw 2. When the wafer box 9 tilts around the horizontal axis parallel to the fourth light 811, the protrusions 92 on both sides of the wafer box shift up and down as the wafer box 9 rotates, and at least one of the fifth light 821 and the sixth light 831 is turned on. The light of any one of the fifth sensor group 82 and the sixth sensor 83 is turned on to generate a fifth signal. After the fifth signal is obtained, it means that the wafer box 9 tilts around the horizontal axis parallel to the fourth light 811. In one embodiment, after the grasping device moves upward by the third preset distance, or after the grasping device moves upward by the sixth preset distance, the following steps are also included:

[0118] Determine whether the first signal, the fourth signal and the fifth signal are detected, and if the fourth signal is detected, issue a first alarm signal, the first alarm signal indicating that the wafer box 9 is tilted around a horizontal axis orthogonal to the fourth light 811;

[0119] If the fifth signal is detected, a second alarm signal is issued, the second alarm signal indicating that the wafer box 9 is tilted around a horizontal axis parallel to the fourth light 811;

[0120] If the fourth signal and the fifth signal are not detected, but the first signal is detected, a third alarm signal is issued, and the third alarm signal indicates that the length of the lifting component or the initial position of the lifting component relative to the mounting plate is wrong.

[0121] See attached Figure 5 As shown, the lifting assembly 3 includes a pressing member 32 and a moving member 31. The moving member 31 and the pressing member 32 are connected by an adjusting member 33 and the distance between the two can be adjusted by the adjusting member 33. The pressing member 32 can abut against the wafer box 9, and the moving member 31 passes through the mounting plate 1. The central area of ​​the clamping portion 91 has a positioning groove for partially embedding the pressing member 32. When the clamping jaws 2 clamp the wafer box 9 and drive the wafer box 9 to leave the process table, the moving member 31 is located below the second light 61. When the clamping jaws 2 grab the wafer box 9 on the process table, the upper end of the moving member 31 should be located between the second light 61 and the first light 51. At this time, the moving member 31 blocks the second light 61 but does not block the first light 51.

[0122] The moving member 31 includes a rod body and a limiting portion. The rod body passes through the mounting plate 1. The limiting portion is fixed at the upper end of the rod body and is located above the mounting plate 1. The limiting portion can abut against the mounting plate 1 to limit the downward movement distance of the rod body. The pressing member 32 is fixed to the lower end of the rod body through the adjusting member 33. The adjusting member 33 adjusts the initial position of the moving member 31 by adjusting the distance between the rod body and the moving member 31 to compensate for the processing error.

[0123] In one embodiment, the adjusting member 33 is a screw, which is rotatably connected to the pressing member 32 and threadedly connected to the moving member 31 . The screw can be rotated to allow the moving member 31 to rise and fall relative to the pressing member 32 to adjust the position of the moving member 31 .

[0124] See attached Figure 5 As shown, the trigger device further comprises a guide member 4 fixed on the mounting plate 1, and the guide member 4 provides guidance for the movement of the rod body. The guide member 4 is a bearing seat and a bearing fixed on the mounting plate 1.

[0125] The lifting assembly 3 further includes a spring 34, which is sleeved on the rod body portion located below the mounting plate 1, and provides a force for the lifting assembly 3 to move downward relative to the mounting plate 1. When the lifting assembly 3 moves upward relative to the mounting plate 1, the spring 34 is compressed, and when the external force is removed, the spring 34 pushes the lifting assembly 3 to quickly return to its original position. The upper end of the spring 34 abuts against the guide member 4, and the lower end abuts against the top pressure member 32.

[0126] The present invention also discloses an overhead crane transport system, the transport system includes an overhead crane and a track, and the overhead crane can move along the track. The overhead crane includes a gripping device and a lifting device, and the overhead crane adopts the above-mentioned transport method. The transport system can accurately transport the wafer box 9, and prevent the wafer box 9 from falling, tilting during transportation, or moving to a misplaced process table.

[0127] The above implementation modes are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for overhead crane transportation, characterized in that: The overhead crane includes a grabbing device that can be raised and lowered under the drive of the lifting device, and the grabbing device includes: a clamping mechanism including a mounting plate and a pair of clamping jaws; A trigger mechanism, comprising a lifting assembly disposed on the mounting plate; The detection mechanism includes a lifting detection component and a clamping detection component, wherein the lifting detection component is used to detect the height of the lifting component when it is lifted by the wafer box, and when the clamp is at the highest position that can clamp the wafer box, a second signal is generated, and when the clamp is at the lowest position that can clamp the wafer box, a first signal is generated, and the clamping detection component is used to detect the translational position of the clamp, and when the clamp is at the clamping position, the clamping detection component generates a third signal; The transport method comprises the steps of placing a wafer box: The lifting device lowers the wafer box to a first preset distance suitable for receiving the wafer box, and determines whether the second signal is detected during the process; If not, after the wafer box descends a first preset distance, determining whether the detection result of the first signal and the second signal is a first preset result, the first preset result being that the second signal is detected and the first signal is not detected; If so, the pair of clamping jaws move away from each other in the horizontal direction by a second preset distance; determining whether the third signal is detected; If not, the grasping device moves upward by a third preset distance to raise the supporting surface of the clamping claw above the supported surface of the wafer box, and in this process, determines whether the detection results of the first signal, the second signal and the third signal are the second preset results, and the second preset result is that the first signal, the second signal and the third signal are not detected; If so, the gripping device is lifted to the initial position before being lowered.

2. The overhead crane transport method according to claim 1, characterized in that: The transport method includes a wafer box taking step, and the wafer box taking step includes: The gripping device moves downward a fourth preset distance suitable for clamping the wafer box; Determining whether the detection results of the first signal and the second signal are first preset results; If so, the pair of clamping jaws move relative to each other in the horizontal direction by a fifth preset distance; determining whether the third signal is detected; If yes, the gripping device moves upward by a sixth preset distance suitable for eliminating the gap between the wafer box and the clamping claw, and determines whether the detection result of the first signal, the second signal and the third signal is a third preset result, wherein the third preset result is that the second signal and the first signal are not detected and the third signal is detected at the same time; If so, the gripping device lifts the wafer box to the transfer position and carries it.

3. The overhead crane transport method according to claim 2, characterized in that: During the process of the gripping device moving downward by a fourth preset distance, the wafer box taking step further includes: It is determined whether the first signal is detected. If so, the grasping device stops moving downward. If not, the grasping device moves downward until it reaches a fourth preset distance.

4. The overhead crane handling method according to any one of claims 1 to 3, characterized in that: The lifting detection assembly includes a first sensor group and a second sensor group fixed to the mounting plate, the first sensor group and the second sensor group are arranged in an up-down direction and have a first light and a second light extending in a horizontal direction, respectively, and the first light and the second light are respectively generated when they are blocked by the lifting assembly. The first signal and the second signal; The clamping detection component includes two third sensor groups respectively fixed on a pair of the clamping jaws, and the two third sensor groups respectively have third light rays extending in the vertical direction on a pair of the clamping jaws. The third signal is generated when the two third light rays are simultaneously blocked by the clamping part of the wafer box.

5. The overhead crane transport method according to claim 4, characterized in that: The detection mechanism also includes a tilt detection component, which includes a fourth sensor group respectively fixed on a pair of the clamps, and the fourth sensor group has a fourth light extending in the horizontal direction. When the wafer box is tilted around a horizontal axis orthogonal to the fourth light, the fourth light is blocked by the wafer box and a fourth signal is generated.

6. The overhead crane transport method according to claim 5, characterized in that: The tilt detection component also includes a fifth sensor group and a sixth sensor group respectively fixed on a pair of the clamps, the fifth sensor group and the sixth sensor group respectively have a fifth light ray and a sixth light ray parallel to the fourth light ray, the fourth light ray is close to the middle of the clamping part of the wafer box, the fifth light ray and the sixth light ray are arranged at intervals on both sides of the fourth light ray, and when the wafer box tilts around a horizontal axis parallel to the fourth light ray, at least one of the fifth light ray and the sixth light ray is turned on and generates a fifth signal.

7. The overhead crane transport method according to claim 6, characterized in that: After the step of the gripping device moving upward by a third preset distance, or after the step of the gripping device moving upward by a sixth preset distance, the following steps are also included: Determine whether the first signal, the fourth signal and the fifth signal are detected. If the fourth signal is detected, a first alarm signal is issued. If the fifth signal is detected, a second alarm signal is issued. If the fourth signal and the fifth signal are not detected but the first signal is detected, a third alarm signal is issued.

8. The overhead crane transport method according to claim 2, characterized in that: The step of moving the grasping device upward by a sixth preset distance further comprises the following steps: During this process, it is determined whether the pulling force applied to the lifting device exceeds a threshold value. If so, the grasping device stops moving upward. If not, after the grasping device moves upward by the sixth preset distance, it is determined whether the detection results of the first signal, the second signal and the third signal are the third preset results.

9. The overhead crane transport method according to claim 1, characterized in that: The lifting assembly includes a pressing member and a moving member, the moving member and the pressing member are connected by an adjusting member and the distance between the moving member and the pressing member can be adjusted by the adjusting member, the pressing member can abut against the wafer box, and the moving member passes through the mounting plate.

10. An overhead crane handling system, characterized in that: The system comprises an overhead crane, the overhead crane comprises a grabbing device and a lifting device, and the overhead crane adopts the handling method described in any one of claims 1-9.

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