A multi-axis robot-based loading and unloading machine

Abstract

A loading / unloading machine based on a multi-axis robot, relating to the field of loading / unloading equipment technology, includes a clamping mechanism, a distance detection module, and a control circuit. The clamping mechanism comprises a motor, a fixing plate, a flange, a guide tube, and a clamping head, all mounted together. The clamping mechanism, distance detection module, control circuit, and multi-axis robot are integrated together. This novel design, based on a multi-axis loading / unloading robot body, uses a motor reduction mechanism to drive the clamping head to grip objects. This prevents the instability that can occur with cylinder-driven clamping heads due to cylinder or piston wear. Under the action of the distance detection module and control circuit, the clamping machine releases the object only after the object has been at a safe distance from the lower object or the ground, reducing the chance of damage due to excessive drop. Considering these factors, this invention has good application prospects.

Description

Technical Field

[0001] This utility model relates to the field of loading and unloading equipment technology, and in particular to a loading and unloading machine based on a multi-axis robot. Background Technology

[0002] Multi-axis loading / unloading robots are industrial equipment used for automated production. They achieve workpiece loading, unloading, and process flow operations through multi-axis linkage. Primarily used in automated production scenarios such as machine tools and assembly lines, they complete workpiece handling, loading / unloading, and inter-process flow tasks, supporting planar and complex spatial movements (such as tilting and tipping). Their structural features typically employ a multi-axis linkage design (e.g., 4-6 axes), achieving precise positioning (accuracy up to ±0.1mm) through servo motor drives, supporting linear and circular trajectory movements. In actual operation, under the programmed control of a central control PLC or host computer (collectively referred to as the control system), the multi-joint motors of the multi-joint arm move according to a set pattern to the relevant workstations on the corresponding equipment, using grippers to clamp parts for loading or release objects for unloading.

[0003] Although existing multi-axis loading and unloading robots meet production needs to some extent, they still have some problems that urgently need improvement due to structural limitations. Specifically, the grippers of existing multi-axis loading and unloading robots are usually driven by the piston rod of a cylinder under the control of the control system to move and clamp the goods (the control system controls the working mode of the four intake and exhaust solenoid valves on the outside of the cylinder of two sets of cylinders respectively. Specifically, the multi-axis loading and unloading robot itself and the supporting control system rely on the program to control the working mode of related electrical equipment, which is a very mature control technology). When the cylinder is working, if the piston or cylinder wears and leaks air, the gripper may not hold the object securely, and there is a chance that the object will fall to the ground and be damaged. Furthermore, when multi-axis loading and unloading robots are used for palletizing operations, the timing of the control system's cylinder operation and the release / unloading of the gripper are fixed (i.e., controlled by the control system's program). However, due to various reasons, such as errors in the control system program or mixed palletizing boxes of varying heights, the gripper may hold boxes with relatively lower heights. Because the control system's logic is based on the higher-height boxes, it may release the gripper at a greater distance, leading to a significant drop due to the larger height difference. The probability of damage to relatively low-height boxes is as follows: (For example, after the control system program has stacked a low-height box in place, the next program will control the stacking of a high-height box. However, due to the work error of the previous worker, the loading station did not stack the relatively high-height box correctly, but instead stacked the relatively low-height box. The clamp holds the relatively low-height box, and the control system controls the clamp to release the box at a relatively high position, causing it to fall onto the box that is now at the bottom. The relatively large drop difference causes the low-height box to be damaged.) Utility Model Content

[0004] To overcome the shortcomings of existing multi-axis loading and unloading robots due to structural limitations, as described in the background, this utility model provides a multi-axis loading and unloading robot body that uses a motor reduction mechanism to drive a gripper to hold objects, reducing the probability of the gripper not holding objects securely. Furthermore, a distance detection module ensures that the gripper is released and the object is placed down only after the object or the ground has reached a safe distance from the lower object, reducing the probability of damage to objects due to excessive drop.

[0005] The technical solution adopted by this utility model to solve its technical problem is:

[0006] A loading / unloading machine based on a multi-axis robot includes a clamping mechanism, a distance detection module, and a control circuit. The clamping mechanism includes a motor, a fixed plate, a flange, a guide tube, and clamping heads, with at least two clamping heads. The upper end of the guide tube is fixedly mounted on the lower end of the fixed plate, and the lower end of the flange is fixedly mounted together with the upper end of the fixed plate. The upper end of the flange is fixedly connected to the forearm connecting plate of the multi-axis robot. The lower end of the guide tube has a guide groove laterally. The upper end of the motor is externally fixedly mounted in the middle of the lower end of the guide tube. The upper ends of the two clamping heads each have threaded holes laterally, and guide blocks are fixedly mounted on the top of each of the two clamping heads. The guide blocks of the two clamping heads slide on both sides of the guide tube, and the upper parts of the two clamping heads slide in the guide grooves respectively; screws are fixedly installed on both sides of the motor shaft, and the outer ends of the two screws are threadedly connected to the threaded holes at the upper ends of the two clamping heads; the control circuit is installed in the control box, and the lower part of one of the clamping heads has an inclined fixing groove, in which the distance detection module is fixedly installed with its detection head tilted downwards; the signal output terminal of the distance detection module is electrically connected to the signal terminal of the control circuit, and the power output terminal of the control circuit is electrically connected to the power input terminal of the motor.

[0007] Preferably, the upper end threads of the two clamping heads are rotated in opposite directions, and the clamping head threads are located outside the lower end of the guide tube.

[0008] Preferably, the front-to-back width of the upper end of the clamping head is smaller than the front-to-back width of the guide groove, and the outer diameter of the guide block is smaller than the inner diameter of the guide tube.

[0009] Preferably, the external threads of the two screws have opposite directions, and the external threads of the screws at the left and right ends of the motor and the internal threads of the clamping head holes at the left and right ends of the guide tube have the same direction.

[0010] Preferably, a protective plate is fixedly installed at the lower end of the motor housing.

[0011] Preferably, the control circuit includes an adjustable resistor and a resistor, a voltage comparator, and a relay that are electrically connected. The positive power input terminal of the relay is connected to the positive power output terminal of the voltage comparator. The positive signal input terminal of the voltage comparator is connected to one end of the adjustable resistor and one end of the resistor. The other end of the resistor is connected to the negative power input terminal and negative signal input terminal of the voltage comparator and the negative power input terminal of the relay.

[0012] Compared with the prior art, the advantages of this utility model are as follows: This utility model is based on a multi-axis loading and unloading robot body, and uses a motor reduction mechanism to drive the gripper head to grip the object. This prevents the problem of unreliable gripping of objects due to wear of the cylinder or piston when using a cylinder-driven gripper head. Under the action of the distance detection module and control circuit, the control system outputs power and the motor releases the gripper via the screw. The gripper is released and the object is lowered only after the object being gripped is at a safe distance from the lower object or the ground. This reduces the probability of damage to the object due to excessive drop. Considering the above factors, this utility model has good application prospects. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0014] Figure 1 This is a schematic diagram of the structure of this utility model installed on a multi-axis robot.

[0015] Figure 2 This is a schematic diagram of the structure of this utility model.

[0016] Figure 3 This is a partial structural diagram of the present invention.

[0017] Figure 4 This is the circuit diagram of this utility model. Detailed Implementation

[0018] Figure 1 , 2As shown in Figures 3 and 4, a loading / unloading machine based on a multi-axis robot includes a power module E1, a clamping mechanism 1, a distance detection module E3, and a control circuit 2. The clamping mechanism 1 includes a motor M1, a fixed plate 101, a flange 102, a rectangular guide tube 103, and two clamping heads 104. The upper end of the guide tube 103 is horizontally fixedly installed on the lower middle part of the fixed plate 101. The lower end of the flange 102 is horizontally fixedly installed on the upper middle part of the fixed plate 101. The upper end of the flange 102 is bolted to the connecting plate at the front end of the forearm of the multi-axis robot 3. The lower middle part of the guide tube 103 has a through guide groove 1031. The upper end of the motor M1 is horizontally fixedly installed on the lower middle part of the guide tube 103. The upper ends of the two clamping heads 104 each have a horizontally fixed guide groove 1031. A through-hole 1041 is provided. A guide block 1042 is fixedly installed on the top of each of the two gripping heads 1041. The guide blocks 1042 of the two gripping heads slide on both sides of the guide tube 103. The upper parts of the two gripping heads 104 slide in the guide grooves 1031. A screw 105 is fixedly installed on both sides of the shaft of the motor M1. The outer ends of the two screws 105 are threadedly connected to the through-hole 1041 at the upper end of the two gripping heads. The power module E1 and the control circuit 2 are installed in the control box 31 of the multi-axis robot. There is a fixed groove 106 with a left-high and right-low tilt at the lower part of the left gripping head. The distance detection module E3 is fixedly installed in the fixed groove 106 with its detection head facing the lower right end (when working, it is aligned with the upper end of a lower object box or the ground).

[0019] Figure 1 , 2 As shown in Figures 3 and 4, the threads of the upper end threaded holes 1041 of the two gripping heads 104 have opposite directions, and the gripping head threaded holes 1041 are located outside the lower end of the guide tube 103. The front-to-back width of the upper end of the gripping head 104 is smaller than the front-to-back width of the guide groove 1031, and the outer diameter of the guide block 1042 (which moves left or right along the guide tube to guide the lateral movement of the gripping head) is smaller than the inner diameter of the guide tube 103. The external threads of the two screws 105 have opposite directions, and the external threads of the screws 105 at the left and right ends of the motor and the internal threads of the gripping head threaded holes 1041 at the left and right ends of the guide tube have the same direction. The lower outer side of each gripping head 104 has a bevel structure (to facilitate gripping objects during descent). A protective plate (to protect the motor) is horizontally fixedly installed at the lower end of the motor M1 housing. The control circuit includes an adjustable resistor RP1 and a resistor R1, a voltage comparator E4, and a relay K1, all connected via circuit board wiring. The positive power input terminal of relay K1 is connected to pin 5 of the positive power output terminal of voltage comparator E4. The positive signal input terminal pin 3 of voltage comparator E4 is connected to one end of adjustable resistor RP1 and one end of resistor R1. The other end of resistor R1 is connected to pin 2 of the negative power input terminal and pin 4 of the negative signal input terminal of voltage comparator E4, as well as the negative power input terminal of relay K1.

[0020] Figure 1 , 2 As shown in Figures 3 and 4, the power input terminals 1 and 2 of the power module E1 are connected to the two poles of the 220V AC power supply via wires. The power output terminals 3 and 4 of the power module E1 are connected to the power input terminals of the control circuit, the voltage comparator E4 (pins 1 and 2), and the distance detection module E3 (pins 1 and 2) via wires. The signal output terminal 3 of the distance detection module E3 is connected to the signal terminal of the control circuit, and the other end of the adjustable resistor RP1 via wires. One of the control power output terminals X1 and X2 of the multi-axis robot control system E2 is connected to the positive and negative power input terminals of the motor M1 via wires. The other control power output terminals X3 and X4 of the multi-axis robot control system E2 are connected to the two control power input terminals of the relay K1 of the control circuit via wires. The two normally open contacts of the relay K1 at the power output terminal of the control circuit are connected to the positive and negative power input terminals of the motor M1 via wires. Power module E1 is an AC 220V to DC 24V power module; motor M1 has a power of 180W; resistor R1 has a resistance of 1.2K; adjustable resistor RP1 has a resistance of 47K (adjusted to 2K in this embodiment); relay K1 is a DC 12V model; distance detection module E3 is a laser rangefinder sensor product of model XKC-KL200, which has two power input terminals (pins 1 and 2) and one signal output terminal (pin 3). The farther the laser rangefinder sensor's probe is from the object, the higher the voltage signal output at pin 3, and vice versa; voltage comparison. Device E4 is a finished voltage comparator based on model LM393. It has two power input terminals (pins 1 and 2), two control signal input terminals (pins 3 and 4), and one positive output terminal (pin 5). When the voltage input to the two control signal input terminals is lower than the threshold voltage, the power output terminal (pin 5) outputs a high level. There is an adjustable resistor on its circuit board for setting the threshold voltage. Before production, the smaller the resistance value of the adjustable resistor, the more power is output when the subsequent input voltage is relatively small. The larger the resistance value of the adjustable resistor, the more power is output when the subsequent input voltage is relatively large.

[0021] Figure 1 , 2As shown in Figures 3 and 4, during operation, the multi-axis loading / unloading robot 3, under the programmed control of the supporting control system E2, controls the movement of its multiple joint motors to the relevant workstations of the relevant equipment (such as palletizing objects). The robot then uses a clamping mechanism to hold components for loading or release objects for unloading. Specifically, the multi-axis loading / unloading robot 3 and its supporting control system rely on program-controlled operating modes of the relevant electrical equipment (in this embodiment, the power output time of the other control power output terminals X3 and X4 of the control system is set relatively long to ensure that the objects are stacked at sufficient time to be placed on top of the next object). This is a very mature existing control technology, which will not be elaborated upon in this application, nor will it provide any protection for the above technical solution. After the AC 220V power supply enters the power input terminal of the power module E1, the DC 24V power supply output from pins 3 and 4 of the power module E1 enters the control circuit and the power input terminal of the distance detection module E3. In this new type of robot, when the first control power output terminals X1 and X2 of the multi-axis loading and unloading robot 3 are in operation, the power is supplied to the positive and negative power input terminals of the motor M. During this time, the rotating shaft of the motor M drives the two screws 105 to rotate clockwise. The two screws 105 drive the left end gripping head 104 to move to the right end and the right end gripping head 104 to move to the left end. The two gripping heads 104 move towards each other and the distance between them decreases. The two gripping heads 104 will then firmly grip the object (when the control system stops outputting power, the gripping heads will no longer move). When the multi-axis loading and unloading robot 3 is operating, its second control power output terminals X3 and X4 output power into the negative and positive power input terminals of motor M. During this time, the rotating shaft of motor M drives the two screws 105 to rotate counterclockwise. The two screws 105 drive the left gripper head 104 to move to the left and the right gripper head 104 to move to the right. The two gripper heads 104 move in opposite directions and the distance between them increases. The two gripper heads 104 will then release the gripped objects and place them on a lower object box (when the control system stops outputting power, the gripper heads will no longer move). Specifically, before the clamping mechanism releases the object, when the distance between the lower end of the probe head of the distance detection module E3 and the next object is relatively far (e.g., more than 8 cm), the voltage signal output by pin 3 of the distance detection module E3 is relatively large. This voltage signal is divided by the adjustable resistor RP1 and the resistor R1 and enters pin 3 of the voltage comparator E4, which is greater than the internal threshold voltage of the voltage comparator E4. As a result, pin 5 of the voltage comparator E4 does not output power, and the relay K1 will not be energized and its control power input terminal and normally open contact terminal will be open. In other words, even if the second control power output terminal X3 and X4 of the control system output power at this moment, the negative and positive power input terminals of the motor reduction mechanism M will not be energized, preventing the object from being damaged due to excessive unloading height.Before the clamping mechanism releases the object, when the distance between the lower end of the probe head of the distance detection module E3 and the next object is relatively close (e.g., less than 8 cm), the voltage signal output from pin 3 of the distance detection module E3 is relatively low. This voltage signal, after being divided by adjustable resistor RP1 and resistor R1, enters pin 3 of the voltage comparator E4, which is lower than the internal threshold voltage of the voltage comparator E4. Therefore, the power output from pin 5 of the voltage comparator E4 enters the positive power input terminal of relay K1, energizing relay K1 and closing its control power input terminal and normally open contact. At this moment, the second control circuit of the control system... The power output from the power supply output terminals X3 and X4 enters the negative and positive power input terminals of the motor reduction mechanism M. After the negative and positive power input terminals of the motor reduction mechanism M are energized, the shaft of the motor M drives the two screws 105 to rotate counterclockwise. The two screws 105 drive the left clamping head 104 to move to the left and the right clamping head 104 to move to the right. The two clamping heads 104 move in opposite directions and the distance between them increases. The two clamping heads 104 will then release the clamped object and place it on a lower object box (when the control system stops outputting power, the clamping heads will no longer move).

[0022] Figure 1 , 2 As shown in Figures 3 and 4, this new invention prevents the problem of unreliable clamping of objects due to wear of the cylinder or piston when using a cylinder-driven clamping head. Under the action of the distance detection module and control circuit, the clamping head is released and the object is lowered only after the clamped object is at a safe distance from the lower object or the ground, which reduces the probability of damage to the object due to excessive drop.

[0023] Those skilled in the art should understand that although this specification describes embodiments, the embodiments do not necessarily contain only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in the embodiments can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. Therefore, the scope of protection of this application is defined by the claims.

Claims

1. A loading and unloading machine based on a multi-axis robot, comprising a clamping mechanism and a distance detection module, characterized in that, It also includes a control circuit; the clamping mechanism includes a motor, a fixed plate, a flange, a guide tube, and clamping heads, with at least two clamping heads. The upper end of the guide tube is fixedly mounted on the lower end of the fixed plate, and the lower end of the flange is fixedly mounted together with the upper end of the fixed plate. The upper end of the flange is fixedly connected to the forearm connecting plate of the multi-axis robot. The lower end of the guide tube has a guide groove laterally. The upper end of the motor is externally fixedly mounted in the middle of the lower end of the guide tube. The upper ends of the two clamping heads each have threaded holes laterally. Guide blocks are fixedly mounted on the top of each of the two clamping heads, and the guide blocks of the two clamping heads slide in different positions. At both ends of the guide tube, the upper parts of the two clamping heads slide within the guide grooves respectively; screws are fixedly installed on both sides of the motor shaft, and the outer ends of the two screws are threadedly connected to the threaded holes at the upper ends of the two clamping heads respectively; the control circuit is installed in the control box, and one of the clamping heads has an inclined fixing groove at its lower part, and the distance detection module is fixedly installed in the fixing groove with its detection head tilted downwards; the signal output terminal of the distance detection module is electrically connected to the signal terminal of the control circuit, and the power output terminal of the control circuit is electrically connected to the power input terminal of the motor.

2. The loading and unloading machine based on a multi-axis robot according to claim 1, characterized in that, The upper threads of the two clamping heads are turned in opposite directions, and the threaded parts of the clamping heads are located outside the lower end of the guide tube.

3. The loading and unloading machine based on a multi-axis robot according to claim 1, characterized in that, The front-to-back width of the upper end of the clamping head is smaller than the front-to-back width of the guide groove, and the outer diameter of the guide block is smaller than the inner diameter of the guide tube.

4. A loading and unloading machine based on a multi-axis robot according to claim 1, characterized in that, The external threads of the two screws rotate in opposite directions, while the external threads of the screws at the left and right ends of the motor and the internal threads of the clamping head holes at the left and right ends of the guide tube rotate in the same direction.

5. A loading and unloading machine based on a multi-axis robot according to claim 1, characterized in that, A protective plate is fixedly installed at the lower end of the motor housing.

6. A loading and unloading machine based on a multi-axis robot according to claim 1, characterized in that, The control circuit includes an adjustable resistor and a resistor, a voltage comparator, and a relay that are electrically connected. The positive power input terminal of the relay is connected to the positive power output terminal of the voltage comparator. The positive signal input terminal of the voltage comparator is connected to one end of the adjustable resistor and one end of the resistor. The other end of the resistor is connected to the negative power input terminal and negative signal input terminal of the voltage comparator and the negative power input terminal of the relay.

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