A micro product grasping device

Abstract

The present invention discloses a micro product grasping device, which includes a data processing module, a negative pressure chamber, an azimuth adjuster and a suction head; an air extraction port is arranged at the upper end of the negative pressure chamber and is connected to an external air extraction device. The present invention uses a piezoelectric sensor to real-time sense the contact force between the suction cup and the object to be grasped, and converts the contact force into an electrical signal and sends it to the data processing module. The data processing module identifies the azimuth where the suction cup contacts the object to be grasped according to the received electrical signal, and then correspondingly adjusts the length adjuster to lift the contact area, reduce the hard contact between the suction cup and the object to be grasped, and prevent the suction cup from damaging the object to be grasped.

Description

Technical Field

[0001] The present invention relates to the field of negative pressure gripping devices, and particularly to a gripping device for micro-products. Background Art

[0002] The gripping of micro-products has always been an important technical link in industrial fields represented by the microelectronics industry. By using negative pressure technology, a local negative pressure field lower than the atmospheric pressure can be generated on the product surface, and thus a lifting force can be formed on the product, so as to realize the suction of the product to complete subsequent operations such as transportation.

[0003] The gripping technology of micro-products has developed with the development of the microelectronics industry, and a variety of technologies have been developed to complete the gripping of corresponding products. Representative technologies include negative pressure gripping, physical clamping, electrostatic suction, electromagnetic suction, etc. Among them, negative pressure gripping has been widely applied due to advantages such as a wide application range, high reliability, and little damage to products. For the gripping of micro-products with smaller and smaller sizes, especially products with a size of sub-millimeters, the requirements for negative pressure gripping technology are getting higher and higher. The main technical problems include: First, in order to match the product, the size of the suction head, especially the size of the suction holes on the suction head, must be smaller and smaller; Second, since the number of suction holes is decreasing, the effective distance between the suction head and the micro-product is getting closer and closer. This requires that when the suction head is working, the parallelism between the suction head and the upper surface of the product is required to be higher and higher. Otherwise, due to displacement deformation caused by temperature changes, vibrations, etc., the surface of the suction head will deflect after long-term work, resulting in suction failure or the suction head crushing the product. These adverse factors are difficult to overcome once and for all by the initial installation of the suction head product. Therefore, it has become an inevitable choice to develop an intelligent suction head technology that can sense and correct the attitude of the suction head in work. Summary of the Invention

[0004] Aiming at the above deficiencies in the prior art, a gripping device for micro-products provided by the present invention solves the problem that the existing negative pressure gripping device cannot adjust the parallelism between the suction head and the object to be gripped in real time, making the suction head easily crush the object to be gripped.

[0005] In order to achieve the above invention purpose, the technical solution adopted by the present invention is as follows:

[0006] Provide a gripping device for micro-products, which includes a data processing module, a negative pressure chamber, an azimuth adjuster, and a suction head; a gas extraction port is provided at the upper end of the negative pressure chamber and is connected to an external gas extraction device;

[0007] The orientation adjuster includes a hollow column, a top cover and a base which are respectively provided with through holes in the middle; the upper end of the hollow column is connected to the inner side of the top cover, and the outer side of the upper surface of the top cover is connected to the negative pressure chamber; the lower end of the hollow column is connected to the inner side of the base, and at least two length adjusters are arranged between the base and the top cover, and the centers of all the length adjusters and the hollow column are not on the same straight line;

[0008] The suction head includes a cavity wall connected to the outer side of the lower surface of the base. The lower end of the cavity wall is provided with an opening. The lower end of the opening is provided with a suction cup protruding from the cavity wall. The upper surface of the opening is provided with a piezoelectric sensor. The upper surface of the piezoelectric sensor is provided with an insulating pressing plate. A compression spring is arranged between the upper surface of the insulating pressing plate and the lower surface of the base; a first ventilation hole is arranged in the middle of the piezoelectric sensor, and a second ventilation hole is arranged in the middle of the insulating pressing plate;

[0009] The data processing module is respectively connected to the piezoelectric sensor and the length adjuster.

[0010] Further, a gold plating layer is arranged on the lower surface of the suction cup.

[0011] Further, the aperture in the suction cup is greater than or equal to 0.01 mm and less than or equal to half of the size of the object to be sucked.

[0012] Further, the piezoelectric sensor is a piezoelectric ceramic sensor. The entire lower surface of the piezoelectric ceramic sensor is an electrode, and four insulating slits from the inside to the outside are arranged on the upper surface, dividing the upper surface of the piezoelectric ceramic sensor into four independent upper electrodes; each upper electrode is connected to the data processing module.

[0013] Further, a signal line interface is arranged on the top cover.

[0014] Further, at least two first fixing holes are arranged on the top cover, and at least two second fixing holes are arranged on the base. The top cover and the base are respectively fixedly connected to the negative pressure chamber and the cavity wall through screws passing through the first fixing holes and the second fixing holes.

[0015] Further, two length adjusters are arranged, and the connecting lines of the centers of the two length adjusters and the hollow column are perpendicular to each other.

[0016] Further, the data processing module is a computer.

[0017] Further, four signal line through holes corresponding to the upper electrodes are arranged on the insulating pressing plate.

[0018] Further, the length adjuster is a piezoelectric telescopic column.

[0019] The beneficial effects of the present invention are as follows: The device can sense the contact force between the suction cup and the object to be grasped in real time through the piezoelectric sensor, convert the contact force into an electrical signal and send it to the data processing module. The data processing module can identify the orientation where the suction cup contacts the object to be grasped according to the received electrical signal, and then correspondingly adjust the length adjuster to raise the contact area, reduce the hard contact between the suction cup and the object to be grasped, and prevent the suction cup from damaging the object to be grasped. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a cross-sectional view of the device;

[0021] Figure 2 is a schematic structural view of the piezoelectric sensor;

[0022] Figure 3 is a top view of the orientation adjuster;

[0023] Figure 4 is a schematic structural view of the insulating pressing plate.

[0024] Wherein: 1, air extraction port; 2, negative pressure chamber; 3, screw; 4, top cover; 5, hollow column; 6, length adjuster; 7, base; 8, cavity wall; 9, insulating pressing plate; 10, suction cup; 11, piezoelectric sensor; 12, compression spring; 13, signal line interface; 14, insulating seam; 15, upper electrode; 16, first ventilation hole; 17, first fixing hole; 18, second fixing hole; 19, signal line through hole; 20, second ventilation hole. DETAILED DESCRIPTION OF THE INVENTION

[0025] The following describes the specific embodiments of the present invention to facilitate those skilled in the art of the present technology to understand the present invention. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those of ordinary skill in the art of the present technology, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, these changes are obvious, and all inventions and creations using the concept of the present invention are within the scope of protection.

[0026] As Figure 1 shown, the micro product grasping device includes a data processing module, a negative pressure chamber 2, an orientation adjuster and a suction head; an air extraction port 1 is provided at the upper end of the negative pressure chamber 2 and is connected to an external air extraction device;

[0027] The orientation adjuster includes a hollow column 5, a top cover 4 and a base 7 with through holes respectively provided in the middle; the upper end of the hollow column 5 is connected to the inner side of the top cover 4, and the outer side of the upper surface of the top cover 4 is connected to the negative pressure chamber 2; the lower end of the hollow column 5 is connected to the inner side of the base 7, and at least two length adjusters 6 are provided between the base 7 and the top cover 4. The centers of all the length adjusters 6 and the hollow column 5 are not on the same straight line, so that each length adjuster 6 can control the adjustment in different directions;

[0028] The suction head includes a cavity wall 8 connected to the outer side of the lower surface of the base 7. An opening is provided at the lower end of the cavity wall 8. At the lower end of the opening, there is a suction cup 10 protruding from the surface of the cavity wall 8. A piezoelectric sensor 11 is provided on the upper surface of the opening. An insulating pressure plate 9 is provided on the upper surface of the piezoelectric sensor 11. A compression spring 12 is provided between the upper surface of the insulating pressure plate 9 and the lower surface of the base 7. The compression spring 12 is in a compressed state to ensure that the piezoelectric sensor 11 is in a stressed state and prevent the piezoelectric sensor 11 from shaking. A first ventilation hole 16 is provided in the middle of the piezoelectric sensor 11, and a second ventilation hole 20 is provided in the middle of the insulating pressure plate 9.

[0029] The data processing module is respectively connected to the piezoelectric sensor 11 and the length adjuster 6, and is used to correspondingly control the length adjuster 6 according to the signal of the piezoelectric sensor 11, so as to adjust the parallelism between the suction cup 10 and the object to be grasped.

[0030] In order to reduce the hard contact between the suction head and the object to be grasped when adjusting the distance and angle from the object to be grasped, and prevent damage to the suction head or the object to be grasped, the suction cup 10 can be made of a metal material, and a gold plating layer is provided on its lower surface. The thickness of the gold plating layer can be set to several micrometers to dozens of micrometers. In order to ensure the grasping effect, the aperture in the suction cup 10 is greater than or equal to 0.01 mm and less than or equal to half of the size of the object to be sucked.

[0031] As Figure 2 shown, in order to ensure the sensitivity of the device and enable the device to sense the force conditions in different directions, the piezoelectric sensor 11 is a piezoelectric ceramic sensor. The entire lower surface of the piezoelectric ceramic sensor is an electrode, and four insulating slits 14 from the inside to the outside are provided on the upper surface, dividing the upper surface of the piezoelectric ceramic sensor into four independent upper electrodes 15; each upper electrode 15 is connected to the data processing module. As Figure 4 shown, four signal line through holes 19 corresponding to the upper electrodes 15 are provided on the insulating pressure plate 9.

[0032] In the specific implementation process, a wireless transmission scheme can be adopted. A wireless transmission device is provided in the cavity wall 8 to send the data of the piezoelectric sensor 11 to the data processing module, or a signal line interface 13 can be provided on the top cover 4, and the signal line of the piezoelectric sensor 11 is led out through the signal line interface 13 and connected to the data processing module.

[0033] As Figure 3As shown in the figure, in order to effectively fix and facilitate the disassembly of the orientation adjuster, the suction cup, and the negative pressure chamber 2, at least two first fixing holes 17 are provided on the top cover 4, and at least two second fixing holes 18 are provided on the base 7. The top cover 4 and the base 7 are respectively fixedly connected to the negative pressure chamber 2 and the cavity wall 8 of the cavity through screws 3 passing through the first fixing holes 17 and the second fixing holes 18. The first fixing holes 17 and the second fixing holes 18 can both be equidistantly arranged in 4 numbers, so that the distance between two adjacent first fixing holes 17 or two adjacent second fixing holes 18 is equal.

[0034] Two length adjusters 6 are provided, and the connecting lines of the centers of the two length adjusters 6 with the hollow column 5 are perpendicular to each other. This setting method can enable the suction cup 10 to have four-way adjustment ability through the length adjustment of the two length adjusters 6. When the data processing module receives the signal of the upper electrode 15 on the left side and does not receive the signals of other upper electrodes 15, it indicates that the object to be grasped is on the left side of the suction cup 10. At this time, if the length adjuster 6 on the same straight line as the upper electrode 15 on the left side and the center point of the suction cup 10 is on the left side of the center point of the suction cup 10, only the length of this length adjuster 6 needs to be contracted to prevent the suction cup 10 from continuing to press against the object to be grasped; similarly, if the length adjuster 6 on the same straight line as the upper electrode 15 on the left side and the center point of the suction cup 10 is on the right side of the center point of the suction cup 10, only the length of this length adjuster 6 needs to be lengthened to prevent the suction cup 10 from continuing to press against the object to be grasped.

[0035] In an embodiment of the present invention, the data processing module is a computer. In addition, the computer as the data processing module preferably can also control the manipulator or other devices that hold this device, so that the manipulator or other devices that hold this device can also perform horizontal movement according to the data of the piezoelectric sensor 11, so that the through holes on the suction cup 10 can be closer to the object to be grasped, thereby improving the grasping efficiency.

[0036] For example, taking a four-axis robot as the carrier, this device is installed on its fourth axis through the air extraction port 1. Gas can enter through the holes of the suction cup 10 and sequentially pass through the piezoelectric sensor 11, the insulating pressing plate 9, the base 7, the hollow column 5, the top cover 4, and the negative pressure chamber 2 to reach the air extraction port 1. The working process of this system is as follows: The four-axis robot drives this device to move to the upper surface of the product to be picked up. During this process, the piezoelectric sensor 11 monitors the grasping process in real time. Based on the four-wire signal output signal of the piezoelectric sensor 11, if the parallelism between the suction cup 10 and the surface of the picked-up product is poor, resulting in abnormal contact signals, the four-axis robot can be directly controlled to stop moving through this signal, and according to the pre-set correction strategy, the expansion and contraction of the piezoelectric telescopic column can be controlled, so as to adjust the angle of the suction cup 10 covered with a gold-plated layer, complete the adjustment of the direction of the suction head. After that, the piezoelectric sensor 11 feeds back the signal to the four-axis robot, and the four-axis robot starts the grasping action again. This process repeats until a good picking action is completed. If during the cycle, the number of cycles exceeds 5 times and the picking action still cannot be completed, the four-axis robot can give an alarm and terminate the action.

[0037] In summary, the present invention can real-time sense the contact force between the suction cup 10 and the object to be grasped through the piezoelectric sensor 11, convert the contact force into an electrical signal and send it to the data processing module. The data processing module identifies the orientation where the suction cup 10 contacts the object to be grasped according to the received electrical signal, and then correspondingly adjusts the length adjuster 6 to raise the contact point, reduce the hard contact between the suction cup 10 and the object to be grasped, and prevent the suction cup 10 from damaging the object to be grasped.

Claims

1. A micro product grasping device, characterized in that It includes a data processing module, a negative pressure chamber (2), an azimuth adjuster, and a suction head; an air extraction port (1) is provided at the upper end of the negative pressure chamber (2) and is connected to an external air extraction device; The azimuth adjuster includes a hollow column (5), a top cover (4) and a base (7) each provided with a through hole in the middle; the upper end of the hollow column (5) is connected to the inner side of the top cover (4), and the outer side of the upper surface of the top cover (4) is connected to the negative pressure chamber (2); the lower end of the hollow column (5) is connected to the inner side of the base (7), and at least two length adjusters (6) are provided between the base (7) and the top cover (4), and the centers of all the length adjusters (6) are not on the same straight line as the center of the hollow column (5); The suction head includes a cavity wall (8) connected to the outer side of the lower surface of the base (7), an opening is provided at the lower end of the cavity wall (8), a suction cup (10) protruding from the cavity wall (8) is provided at the lower end of the opening, a piezoelectric sensor (11) is provided on the upper surface of the opening, an insulating pressing plate (9) is provided on the upper surface of the piezoelectric sensor (11), and a compression spring (12) is provided between the upper surface of the insulating pressing plate (9) and the lower surface of the base (7); a first ventilation hole (16) is provided in the middle of the piezoelectric sensor (11), and a second ventilation hole (20) is provided in the middle of the insulating pressing plate (9); The data processing module is respectively connected to the piezoelectric sensor (11) and the length adjuster (6); The piezoelectric sensor (11) is a piezoelectric ceramic sensor, the entire lower surface of the piezoelectric ceramic sensor is an electrode, and four insulating slits (14) from the inside to the outside are provided on the upper surface, dividing the upper surface of the piezoelectric ceramic sensor into four independent upper electrodes (15); each upper electrode (15) is connected to the data processing module; The aperture in the suction cup (10) is greater than or equal to 0.01 mm and less than or equal to half of the size of the object to be sucked.

2. The micro product grasping device according to claim 1, characterized in that, A gold plating layer is provided on the lower surface of the suction cup (10).

3. The micro product grasping device according to claim 1, characterized in that, A signal line interface (13) is provided on the top cover (4).

4. The micro product grasping device according to claim 1, characterized in that, At least two first fixing holes (17) are provided on the top cover (4), at least two second fixing holes (18) are provided on the base (7), and the top cover (4) and the base (7) are respectively fixedly connected to the negative pressure chamber (2) and the cavity wall (8) by screws (3) passing through the first fixing holes (17) and the second fixing holes (18); 5. The micro product grasping device according to claim 1, characterized in that, The number of the length adjusters (6) is set to two, and the connecting lines of the two length adjusters (6) with the center of the hollow column (5) are perpendicular to each other.

6. The micro product gripping device according to claim 1, characterized in that, The data processing module is a computer.

7. The micro product grasping device according to claim 1, wherein Four signal line through holes (19) corresponding to the upper electrodes (15) are provided on the insulating pressing plate (9).

8. The micro product grasping device according to claim 1, wherein, The length adjuster (6) is a piezoelectric telescopic column.

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