Curved mechanism for folding down workpiece fixtures in containers
The cam mechanism with a curve segment and control system addresses the reliability issues of existing workpiece holder folding, ensuring accurate and durable folding to 90° with fault detection.
Patent Information
- Application Number
- DE202024001358
- Authority / Receiving Office
- DE · DE
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2024-12-19
- Estimated Expiration
- 2034-07-31
AI Technical Summary
Existing mechanisms for folding down workpiece holders in containers fail to reliably achieve the 90° end position due to mechanical limitations and lack of positional control, leading to incorrect placement of workpieces and machine malfunctions.
A cam mechanism utilizing a curve segment driven by a cylinder, coupled with a telescopic linear unit, ensures complete folding from -20° to 90°, incorporating a control system for force limitation and end position monitoring.
Ensures reliable and complete folding of workpiece holders to 90°, preventing mechanical damage and improving placement accuracy while allowing for fault detection and replacement of defective holders.
Smart Images
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Abstract
Description
[0001] The invention consists of a cam mechanism for the reliable and complete folding down of trays for receiving workpieces that are placed in containers by a robot within an automated system.
[0002] In Fig. 1 is the functioning of the entire system and in Fig. 2 shows the placement of the workpieces in the containers.
[0003] Fig. Figure 3 shows the known state of the art for folding down the workpiece holders and Fig. 4 and Fig. 5 the invention described herein.
[0004] The following symbols are used: 1 robot 2 robot grippers 3 protective fence 4 containers for workpieces 5 workpieces 6 Mechanism for folding workpiece holders 7 Workpiece holder 8 Workpiece holder in starting position -20° 9 workpiece holders in end position 90° 10 Height adjustment unit 1st to nth position workpiece 11 Rotary axis workpiece holders 12 linear units, simple 13 cylinders with tappets 14 telescopic linear units 15 Curve segment 16 Storage 17 cylinders for drive curve segment 18 cams and switches for monitoring the end position
[0005] In the presentation Fig. 1 In an automatic system secured with a safety fence (3), the workpieces (5) are placed in rows and in layers on top of each other in a container (4) in workpiece holders (9) using a robot (1) and associated grippers (2).
[0006] When the first layer (rows 1 to n) is completely filled with workpieces as in Fig. 2 shown, then for the next layer of workpieces the workpiece support (7) is folded around its axis of rotation (11) from the starting position (8) to the end position (9) by a mechanism (6) which is supplied horizontally (12) and vertically (10) from outside the container (4).
[0007] The known mechanism Fig. 3 according to the state of the art consists of a linear unit (12) driven by a cylinder for horizontal delivery towards the container and a pneumatic plunger (13) which rotates the workpiece holder (7) about its axis of rotation (11) from about - 20° to + 30° as a result of its tangential force action.
[0008] Kinematically, this involves a conversion from a translational movement into a rotational movement.
[0009] The disadvantage of this technical solution is that beyond the rotation angle of +30° no force can be applied with the tangential plunger (13) and the workpiece holders rotate to the end position of 30° to 90° only with their own weight.
[0010] The movement sequence after an angle of +30° is prone to malfunctions, as the workpiece holders do not reach the final position of 90° due to stiffness in the bearings or other mechanical damage.
[0011] There is also no control of the end position within the mechanism using switches that could report an incomplete movement sequence to the control system.
[0012] As a result, the workpieces are incorrectly placed by the robot onto the workpiece holders which are not in their final position, and the process in the system is disrupted.
[0013] Due to the tangential positioning of the plunger on the workpiece holder, transverse force components are created which negatively affect the reliability and service life of the mechanism.
[0014] When the plunger returns to its starting position, it often gets stuck on the workpiece holder, which is not fully folded down, causing machine malfunctions or even damage itself.
[0015] The invention of the cam mechanism, in Fig. As shown in Figure 4, this solves these problems by using a curve segment (15) that moves the workpiece holder completely from -20° to the end position of 90°, a total of 110°, under force. The kinematic principle is the coupling of two rotational movements.
[0016] The pivot point of the cam segment's kinematics coincides with the pivot point of the workpiece holder. Therefore, the cam segment presses perpendicularly against the wall of the workpiece holder, and no transverse force components are generated.
[0017] A cylinder (17) is used as a drive for the curve segment, which is pneumatically, hydraulically or electrically actuated.
[0018] The cylinder (17) can be combined with a force limiting control system (for example, with a pressure regulating valve or pressure sensor). This allows a predefined maximum permissible torque of the workpiece holders at which the cylinder should no longer move to its end position. When the predefined value is reached, the system is signaled a fault, and the container with the defective workpiece holder can be replaced.
[0019] In confined spaces, the cam mechanism is supplied using a telescopic linear unit (14).
[0020] The process is described as follows: 1. Delivery curve mechanism with telescopic linear unit (14) 2. Rotating with cam segment (15) using cylinder (17) until reaching end position (9) 3. The cam segment is supported (16) in rollers to minimize wear. 4. Monitoring of end position 110° with switch (18)
[0021] In Fig. Figure 5 shows an exemplary embodiment of the curve mechanism.
Claims
[] Cam mechanism for the reliable rotary movement of workpiece holders into the end position within containers for the storage of workpieces characterized by that, 1. the force is applied up to the end position of the workpiece holders and thus disturbances due to an incomplete movement sequence are excluded.
2. the reaching of the end position of the workpiece holders is controlled by a switch.
3. the horizontal delivery is carried out in a space-saving manner by a telescopic linear unit.
4. no adverse transverse force components arise due to the vertical force acting on the curve segment.
5. Defective workpiece holders can be detected by adjusting or measuring the pressure in the drive cylinder.