CN110270874A - A kind of truss-like lathe loading and unloading robot system and its control method - Google Patents

Abstract

The invention provides a truss type machine tool loading and unloading robot system and a control method thereof, which belong to the technical field of machine tool automatic processing. The system includes a truss robot, a feeding tray, a feeding tray and a CNC lathe. The loading tray and the unloading tray are located between two CNC machine tools. Workpiece transfer between CNC machine tools. The truss robot adopts a four-degree-of-freedom structure, including a walking unit, a rotating unit, a grabbing unit, and a control unit. The loading tray is used to place the ball cage workpieces to be processed in batches. The motor transports the workpiece to the finished product centralized storage area according to the processing incoming materials; the CNC lathe includes a spindle box, a chuck, a feeding mechanism, and a control system. The invention can realize the free placement of the feeding tray and the flexible switching between the single-process processing and the double-process processing of the ball cage through the simple four-degree-of-freedom design and the control of the loading and unloading process.

Description

A loading and unloading robot system for a truss machine tool and its control method

technical field

The invention relates to the technical field of machine tool automatic processing, in particular to a truss type machine tool loading and unloading robot system and a control method thereof.

Background technique

CNC machine tools are key equipment widely used in the metal parts manufacturing and processing industry. They have high requirements for processing accuracy and processing efficiency. Most of the traditional methods use manual installation and disassembly of parts on the CNC machine tool, and complete the operation of the machine tool. The working environment of the operator is poor, the labor intensity is high, and the distance from the moving parts of the machine tool is close, which has potential safety hazards. With the development of digital control and information technology, the use of integrated equipment with few or no people to complete the loading and unloading of CNC machine tools can realize automatic production, which is an ideal way for metal parts manufacturing and processing enterprises. Due to their remarkable features and advantages such as high degree of automation, good environmental protection, and strong practicability, industrial robots are gradually being used more and more widely in the machinery manufacturing industry, and will become mainstream auxiliary equipment for modern mechanical processing. Reasonable use of industrial robot automation equipment can replace operators to complete dangerous, repetitive and boring work, reduce human labor intensity, reduce costs and improve efficiency for enterprise production.

Industrial robots used for loading and unloading control of CNC machine tools are mainly divided into two types: joint robots and truss robots. Among them, joint robots generally adopt four to six degrees of freedom, with flexible operation and good equipment adaptability. Most of them use precision reducer transmission, high repeat positioning accuracy, and high machining accuracy of parts. However, the control technology is complicated and the robot price is high. Follow-up maintenance higher cost. The truss robot belongs to the rectangular coordinate robot. It often adopts the transmission mode of ball screw, synchronous belt or rack and pinion. It also has auxiliary functions such as inter-process transportation, automatic loading and unloading and material rotation. Its advantages are relatively low cost and simple control system. However, the system generally has problems such as poor adaptability to workpiece placement, workpiece shape, and processing flow. The inner ball cage and the outer ball cage are also called constant velocity universal joints, which are important parts of the car to transmit power to the tires. The ball cage is a typical and highly demanded part that needs to be processed by a CNC lathe. Product processing quality and efficiency have higher requirements. Since the shape of the ball cage part is generally called a bell shape with a thin top and a thick bottom, and the thick end generally has an inner hole that needs to be chamfered, it often takes two processes to complete the machining of a finished product, causing the general truss robot to perform The automatic loading and unloading of ball cage parts will encounter difficulties in the continuous positioning and grabbing of the loading tray and the switching of different processing procedures.

Contents of the invention

The technical problem to be solved by the present invention is to provide a truss-type machine tool loading and unloading robot system and its control method. Through simple four-degree-of-freedom design and loading and unloading process control, on the basis of keeping the truss-type robot structure simple and low in cost, it can The free placement of the loading tray and the flexible switching between single-process processing and double-process processing of the ball cage can be realized. This method can effectively improve the scope of application and overall operating efficiency of the truss-type loading and unloading robot for CNC machine tools.

The system includes a truss robot, a feeding tray, a feeding tray and a CNC lathe. The loading tray and the unloading tray are located between two CNC machine tools. The workpiece is transferred between the machine tool and the CNC machine tool; the truss robot is composed of a rack and pinion, a reducer, a drive motor, a rotating mechanism and a pneumatic gripper, of which there are two pneumatic grippers, namely the loading gripper and the unloading gripper , the loading gripper is used to grab the workpiece to be processed, and the unloading gripper is used to remove the processed workpiece; the two CNC machine tools are respectively located at the lower left and lower right of the transverse axis of the truss robot, the feeding tray and the unloading The feeding tray is located between the two CNC machine tools, the loading tray places the workpieces to be processed, and the unloading tray places the processed workpieces.

Among them, the truss robot adopts a four-degree-of-freedom structure, including a walking mobile unit, a rotating unit, a grasping unit, and a control unit. The mobile unit includes a rack and pinion, a reducer, and a drive motor for driving the workpiece to move horizontally and vertically; The rotating unit is a pneumatic rotating mechanism, which is used to adjust the spatial angle of the workpiece, including horizontal and vertical rotation and rotation; the grabbing unit includes two pneumatic grippers for grabbing the workpiece. The truss-type robot control unit is the signal processing unit of each detection and execution element of the truss-type robot, which is responsible for exchanging signals with the CNC machine tool and independently completing the set loading and unloading process.

The feeding tray is used to place the ball cage workpieces to be processed in batches. The feeding tray adopts a step-by-step movement method and adopts a frame structure, including a feeding belt, a tray bottom support, a proximity switch, a shooting sensor, and a feeding motor. , the feeding belt is located on the top of the feeding tray, adopts a crawler structure, the tray bottom bracket is fixed on the feeding belt in batches, and is used for the positioning of the workpiece. Each tray bottom bracket corresponds to a feeding station; the surrounding of the feeding belt is set The proximity switch used to detect whether there are workpieces in each feeding station and the through-beam sensor whether the single-row grabbing is completed; the feeding motor drives the tray base to move.

A total of six proximity switches are set on the feeding tray, five of which are located side by side directly above the feeding station, and the other proximity switch is installed under the feeding belt; the through-beam sensor is fixed on both sides of the workpiece grabbing position, all detection The component signals are all connected to the gantry robot control unit.

The unloading tray adopts a frame structure as a whole, and a crawler-type mobile feeding belt is set on the top, and the drive motor transports the workpieces to the finished product centralized storage area according to the processing and incoming materials.

The CNC lathe includes a spindle box, a chuck, a feed mechanism, and a control system. The spindle box includes a spindle and a transmission mechanism. The main function is to support the spindle and make it rotate. The chuck is installed at the front end of the spindle of the CNC lathe to fix the workpiece The hydraulic mechanism and the feed mechanism are the mechanical parts that complete the cutting process. The CNC machine tool control system completes the chuck tightening, spindle start and stop and positioning, cutting amount control, and is responsible for exchanging signals with the truss robot control unit.

The method for controlling the loading and unloading robot system of the truss type machine tool includes the following steps:

S1: The ball cage workpieces to be processed are transferred by the billet making process or manually placed in batches by the operator on the bottom tray of the feeding belt on the top of the feeding tray;

S2: The feeding tray and the feeding belt move forward step by step until the workpiece to be processed is detected at the proximity switch used to judge whether the workpiece exists, and the row with the workpiece is moved to the position to be grabbed, and the truss robot is notified to carry out reclaiming operation;

S3: The truss-type robot’s loading gripper grasps the workpiece to be processed on the feeding tray, then adjusts the spatial attitude of the ball cage workpiece to be processed, and simultaneously moves the horizontal and vertical mechanisms of the truss-type robot to transfer the ball cage workpiece to be processed To the top of the machine door of the CNC machine tool;

S4: Waiting for the call signal after the processing of a workpiece on the CNC machine tool is completed, the control unit sends out the operation of opening the machine door, and the truss-type robot gripper sends the ball cage workpiece to be processed to the parallel position of the CNC machine tool spindle. At this time, the truss-type robot first uses The gripper without the workpiece performs the unloading operation on the processed workpiece on the spindle, and the workpiece to be processed is loaded after rotating the gripper;

S5: After the truss-type robot gripper moves the captured workpiece out of the CNC lathe, the control unit issues the operation of closing the machine door and notifies the CNC machine tool to perform cutting processing, and at the same time transfers the processed workpiece to other CNC machine tools for the next process Cutting or sending to the feeding tray for display;

S6: After completing the processing of one or two processes, the truss-type robot unloading gripper grabs the finished workpiece and places it on the unloading tray, the control unit issues an operation command for the unloading tray, and the drive motor transports the finished workpiece to the centralized At the same time, the truss robot drives the feeding claw to grab the next workpiece to be processed.

The beneficial effects of above-mentioned technical scheme of the present invention are as follows:

In the above scheme, through the simple four-degree-of-freedom design and the control of the loading and unloading process, the free placement of the feeding tray and the flexible switching between single-process processing and double-process processing of the ball cage can be realized, specifically reflected in:

(1) In order to reduce manufacturing costs, the truss-type robot can only move horizontally and vertically, so the pneumatic gripper installed on the front end can only grab the workpiece on a vertical plane. The parking position with the material meets the space grabbing conditions of the pneumatic gripper, and a proximity switch is installed at the bottom of the feeding tray for accurate parking;

(2) In order to realize the accurate judgment of the truss robot when the feeding tray is empty under artificial or abnormal conditions, and to avoid the occurrence of empty processes without workpieces and reduce efficiency, especially in the front row of the position to be grabbed Based on the proximity switch for judging the presence or absence of the workpiece, and the through-beam sensor for detecting the completion of all the materials in the row to be grabbed, the control unit of the truss robot determines the grabbing of each position on the row to be grabbed on the loading tray according to the corresponding state or empty action.

(3) The specially designed rotating unit with horizontal and vertical rotation and rotation functions and double pneumatic gripper design of the truss robot make the workpiece have a variety of variable postures in the space position of picking up the material from the feeding tray and loading and unloading the CNC machine tool , Through the instruction conversion of the truss-type robot control unit to the moving unit and the rotating unit actuator, the free switching between single-process processing and double-process processing of ball cage parts can be realized.

Description of drawings

Fig. 1 is a schematic structural diagram of a truss type machine tool loading and unloading robot system facing two CNC machine tools according to an embodiment of the present invention;

Fig. 2 is the structural representation of the feeding tray of the truss type machine tool loading and unloading robot system of the present invention;

Fig. 3 is a schematic diagram of signal interaction of the control system of the truss type machine tool loading and unloading robot system of the present invention;

Fig. 4 is a schematic diagram of the loading and unloading process of the truss type machine tool loading and unloading robot system of the present invention.

Among them: 1-truss robot; 2-CNC machine tool; 3-loading tray; 4-unloading tray; 31-feeding belt; 32-bottom support of tray; 33-proximity switch; 35-feeding motor.

Detailed ways

In order to make the technical problems, technical solutions and advantages to be solved by the present invention clearer, the following will describe in detail with reference to the drawings and specific embodiments.

The invention provides a truss type machine tool loading and unloading robot system and a control method thereof.

As shown in Figure 1, the system includes a truss robot 1, a loading tray 3, a blanking tray 4 and a CNC lathe 2, the loading tray 3 and the blanking tray 4 are located between two CNC machine tools 2, The truss-type robot 1 transmits workpieces between the loading tray 3, the unloading tray 4 and the CNC machine tool 2; the truss-type robot 1 is composed of a rack and pinion, a reducer, a drive motor, a rotating mechanism and a pneumatic gripper. There are two pneumatic grippers, namely the loading gripper and the unloading gripper; two CNC machine tools 2 are respectively located at the lower left and lower right of the transverse axis of the truss robot 1, and the feeding tray 3 and the discharging tray 4 Located between two CNC machine tools 2, the loading tray 3 places workpieces to be processed, and the unloading tray 4 places finished workpieces.

As shown in Figure 2, the feeding tray adopts a frame structure, including a feeding belt 31, a tray bottom support 32, a proximity switch 33, a through-shot sensor 34, and a feeding motor 35. The feeding belt 31 is located at the bottom of the feeding tray 3 The top adopts a crawler structure, and the tray bottom support 32 is fixed on the feeding belt 31 in batches for the positioning of the workpiece. Each tray bottom support 32 corresponds to a loading station; the surrounding area of the feeding belt 31 is used to detect each feeding Whether the station has a proximity switch 33 for workpieces and a cross-shot sensor 34 for whether the single-row grabbing is over; the feeding motor 35 drives the tray bottom support 32 to move, thereby driving the workpiece to be processed placed on the top of the bottom support to move. The feeding tray 3 is provided with six proximity switches 33, of which five proximity switches 33 are located side by side directly above the feeding station, and are used to detect whether there is a workpiece to be processed on the corresponding feeding station. If the station detects If there is no workpiece, the truss-type robotic gripper will pass through this position when retrieving materials to prevent missed or empty grasping of the workpiece. Another proximity switch 33 is installed under the feeding belt 31 to detect whether the bottom support of a row of trays has moved to The position to be grasped ensures that the feeding belt stops accurately when moving; the through-beam sensor 34 is fixed on both sides of the workpiece grasping position, and detects whether all the materials on the tray bottom bracket at the current grasping position have been taken out. When the through-beam sensor 34 Conduction means that there is no workpiece to be taken out in this row. At this time, the feeding motor 35 rotates, and the bottom support of the next discharge tray is transported to the row to be grabbed.

Figure 3 shows a schematic diagram of the signal interaction of the truss robot control system for automatic loading and unloading of machine tools. The signals that the truss robot control system needs to collect mainly include proximity switch signals, through-beam sensor signals, machine door switch signals, etc. Processing completion signal, running status signal, etc. of automatic interlocking operation of machine tool and truss robot. The output of the truss-type robot control unit mainly controls the X-axis and Z-axis moving units of the truss-type robot, the rotation unit of the gripper, the pick-and-place execution unit of the gripper, and the execution unit of the CNC machine tool, as well as the feeding tray and unloading Logic control of the tray.

Figure 4 shows the flow chart of the truss robot performing automatic loading and unloading operations on two machine tools at the same time. Here, the process is described by taking two processes of two machine tools processing the same workpiece as an example. The specific steps are as follows:

Step 1: The gripper of the truss-type robot reaches the top of the feeding tray, and judges whether there are workpieces in the row to be grabbed on the feeding tray, and if so, go to step 3, otherwise go to step 2;

Step 2: The feeding motor of the feeding tray rotates, the feeding belt moves one row, and then step 1 is performed;

Step 3: The moving unit of the truss-type robot's gripper moves to reach the material picking place, adjust the grabbing angle through the rotating unit, and the grabbing unit drives to perform the material picking action;

Step 4: The mobile unit of the truss robot moves, and transports the gripper grabbing the workpiece to the top of the CNC machine tool 1, and waits for the CNC machine tool 1 to finish processing;

Step 5: After the CNC machine tool 1 is finished processing and sends out a call signal, the door of the CNC machine tool 1 is opened, and the moving unit and the rotating unit of the truss robot move respectively to move the gripper mechanism to the refueling place of the CNC machine tool 1 for refueling operation. The material claw removes the workpiece that has been processed by the CNC machine tool, and then the loading claw installs the workpiece to be processed;

Step 6: After completing the refueling operation of CNC machine tool 1, the truss-type robot moving unit moves to move the gripper mechanism to the top of CNC machine tool 1, the door of the machine tool is closed, and CNC machine tool 1 automatically starts processing;

Step 7: The mobile unit of the truss robot moves, and transports the gripper that grabs the workpiece to the top of the CNC machine tool 2, and waits for the processing of the CNC machine tool 2 to complete;

Step 8: After the second processing of the CNC machine tool is completed and the call signal is sent, the second door of the CNC machine tool is opened, and the moving unit and the rotating unit of the truss robot move respectively, and the gripper mechanism is moved to the refueling place of the second CNC machine tool for refueling operation. The material gripper removes the finished workpiece that has been processed by the CNC machine tool 2, and then the feeding gripper installs the workpiece removed from the CNC machine tool 1 onto the CNC machine tool 2;

Step 9: After completing the second refueling operation of the CNC machine tool, the mobile unit of the truss robot moves to move the gripper mechanism to the top of the CNC machine tool 2, the machine door is closed, and the CNC machine tool 2 automatically starts processing;

Step 10: The mobile unit of the truss-type robot moves the gripper carrying the finished workpiece to the unloading tray for unloading operation, and at the same time, the unloading motor rotates to complete the transportation of the finished workpiece, completing a working cycle. Then proceed to step 1.

The above description is a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, these improvements and modifications It should also be regarded as the protection scope of the present invention.

Claims (6)

1. a kind of truss-like lathe loading and unloading robot system, it is characterised in that: including gantry robot (1), feeding charging tray (3), blanking charging tray (4) and numerically controlled lathe (2), feeding charging tray (3) and blanking charging tray (4) are located between two numerically-controlled machine tools (2), Gantry robot (1) carries out workpiece transmission between feeding charging tray (3), blanking charging tray (4) and numerically-controlled machine tool (2)；Truss-like Robot (1) is made of rack-and-pinion, speed reducer, driving motor, rotating mechanism and Pneumatic paw, and wherein Pneumatic paw has two Only, respectively feeding gripper and blanking gripper；Two numerically-controlled machine tools (2) are located at a left side for gantry robot (1) lateral shaft Lower section and lower right, feeding charging tray (3) and blanking charging tray (4) are located between two numerically-controlled machine tools (2), and feeding charging tray (3) is placed Workpiece to be processed, blanking charging tray (4) place the workpiece completed the process.

2. truss-like lathe loading and unloading robot system according to claim 1, it is characterised in that: the truss-like machine People (1) uses four-degree-of-freedom structure, including walking mobile unit, rotary unit, picking unit, control unit, wherein mobile single Member includes rack-and-pinion, speed reducer, driving motor；Rotary unit is Pneumatic rotary mechanism；Picking unit includes two crawl works The Pneumatic paw of part.

3. truss-like lathe loading and unloading robot system according to claim 1, it is characterised in that: the feeding charging tray (3) use tower structure, including feeding belt (31), charging tray collet (32), close to switch (33), opposite type sensor (34), on Expect motor (35), feeding belt (31) is located at the top of feeding charging tray (3), and using track structure, charging tray collet (32) batch is solid It is scheduled on feeding belt (31), for the positioning of workpiece, the corresponding feeding station of every charging tray collet (32)；Feeding belt (31) week Side setting for detect each feeding station whether there is or not workpiece close to switch (33) and whether sensing to penetrating of terminating of single crawl Device (34)；Feeding motor (35) drives charging tray collet (32) mobile.

4. truss-like lathe loading and unloading robot system according to claim 3, it is characterised in that: the feeding charging tray (3) it is arranged six in altogether close to switch (33), wherein five are located side by side at the surface of feeding station close to switch (33), in addition One is mounted below feeding belt (31) close to switch (33)；Opposite type sensor (34) is fixed on the two sides of workpiece grabbing position.

5. truss-like lathe loading and unloading robot system according to claim 1, it is characterised in that: the blanking charging tray (4) whole to use tower structure, crawler-type mobile feeding belt is arranged in top, by driving motor according to processing supplied materials situation by work Part is delivered to finished product and area is centrally placed.

6. the method for controlling truss-like lathe loading and unloading robot system described in claim 1, it is characterised in that: including step It is as follows:

S1: cage batch workpiece to be processed is placed on the feeding belt charging tray collet at the top of feeding charging tray；

S2: feeding magazine feed band stepped advancement will have a row of workpiece until detecting workpiece to be processed close at switch It is moved to crawl position, gantry robot is notified to carry out feeding operation；

S3: gantry robot's feeding gripper carries out grasping manipulation to workpiece to be processed on feeding charging tray, then adjusts to be added Work cage workpiece space posture, while the mobile horizontal and vertical mechanism of gantry robot, cage workpiece to be processed is transmitted to Above the machine tool door of numerically-controlled machine tool；

S4: waiting the call signal on numerically-controlled machine tool after the completion of a work pieces process, and control unit, which issues, opens lathe door operation, purlin Cage workpiece to be processed is sent into main shaft of numerical control machine tool parallel position by posture robot hand, at this point, gantry robot is first The machined completion workpiece on main shaft is subjected to blanking operation with the gripper of no workpiece, rotate after gripper by workpiece to be processed into The operation of row feeding；

S5: after the machined completion workpiece grabbed is removed numerically controlled lathe by gantry robot's gripper, control unit, which issues, is closed It closes lathe door operation and numerically-controlled machine tool is notified to carry out machining, while the progress of other numerically-controlled machine tools of Workpiece transfer will be completed the process The machining of subsequent processing or send to blanking charging tray is put；

S6: after the processing for completing one or two process, gantry robot's blanking gripper grabs finished work-piece in blanking charging tray Completion is put, and control unit issues blanking charging tray operating instruction, is delivered to finished work-piece by driving motor and area is centrally placed, together When gantry robot drive feeding gripper to carry out the grasping manipulation of next workpiece to be processed.