Kinematic Simulation of Automatic Conveying and Stamping Machine based on UGNX

: This paper designed a kind of automatic conveying and stamping machine, which was mainly used for drawing thin sheet metal. UGNX software was used to design the motion law of the mechanism and the simulation mechanism. The time displacement diagram obtained by theoretical calculation and simulation was compared to verify the correctness of theoretical analysis and the rationality of the design. The comparison shows that the device meets the requirements of theoretical calculation. The device has the characteristics of simple structure, high efficiency and easy operation, which provides a reference for the subsequent realization of conveying and stamping devices with different requirements.


Introduction
Automatic conveying and stamping machine, is a kind of automatic material conveying equipment, compared with the traditional conveyer operation, it is more simple, higher degree of automation, widely used in light, heavy industry parts stamping, is an important device. The type of automatic conveyer on the current market is relatively single, the market is still not perfect. This paper designs a machine, which make guide rod institution with swing rod institution together to be as the stamping institution, crank slider institution as the conveying institution. It has the characteristics of easy design, simple structure and good conformity with the actual production requirements. It provides the reference for different production requirements.

Automatic conveying and stamping machine overall design scheme 2.1 The design requirements
In this paper, the automatic conveying and stamping machine for metal sheet billet from the side to stay processing position. Upper die with larger speed nearly blank first and then down at a constant speed, forming work, continue downward billet products will launch of upper die cavity after, finally back quickly, to complete a working cycle.Its requirements are: (1) Stamping execution component have the movement characteristics as following：close to the workpiece with a fast speed, uniform down the stretch and fast return the beginning position.
(2) Fine forming products productivity about 30 pieces per minute.
(3) On mobile total distance of 280 mm, the drawing schedule in the central part of total travel, about 100 mm.
(4) Travel speed ratio coefficient is 1.2 or higher. (5) The transporting material maximum distance of 200 mm.

Design flow chart
The design of the automatic conveying and stamping machine flow chart is shown in Fig. 1 [1].

Conveying institution design and modeling
Conveying institution include: rack, crank, connecting rod, guide rod, nut, driven gear, etc. Conveying institution are mainly consisted of crank connecting rod institution and guide bar institution [2].The institution has the character of reciprocating motion, can realize the request of conveying.According to the change of the crank and connecting rod length, can realize different conveying requirements.
Conveying institution diagram as shown in Fig. 2.
Using UGNX to conveying institution are modeled as shown in Fig. 3. 1 -gear; 2 -crank; 3 -connecting rod; 4 -rack; 5guide bar  3.2 Stamping design and modeling of the institution Stamping institution mainly includes: rack, gear, shaft, rocker, guide rod, punch, slider, driven gear, etc.Stamping institution is mainly composed of slider-crank mechanism of guide bar mechanism.The institution is quickly approaching, uniform motion, fast return movement characteristics, can well realize the request of stamping [3]. Stamping institution diagram as shown in Fig. 4. Using UGNX to stamping institution are modeled as shown in Fig   As shown in Fig. 6 is the automatic conveying and stamping machine,which has entered the simulation interface.Its conveying institution is a offset slider-crank mechanism, which has simple structure, convenient operation, can be a very good implementation movement back and forth [5].Stamping institution for rocker guide bar mechanism, this mechanism can achieve good fast approaching, drawing at a constant speed, fast return work requirements [6]. Transmission part as input by the gear wheel 3, gear 2 and gear 5 as a driven wheel, respectively independent input to convey institution and stamping institution, to achieve the overall transmission. The number of teeth for the gear 3 is 240; The number of teeth for the gear 2 and gear 5 is 120, so the total transmission ratio of 1:1.

Define the connecting rod
Definition of connecting rod general method are following: defines the same motion components for the same connecting rod;Static components are defined as fixed connecting rod;Of motion simulation is independent components can be omitted. The rack 6、8、11、12, respectively defined as fixed connecting rod L001, L002, L003, L004;The input gear 3 defined as connecting rod L006;Driven gear 2 and the crank have the same motion, therefore, defined as connecting rod L005;On the driven gear 5 and its crank due to have the same motion, therefore, defined as connecting rod L007;Connecting rod 1 defined as L008;Guide bar 13 is defined as the connecting rod L009;Rocker defined as connecting rod L010;Sliding block 7 and 9 respectively defined as connecting rod L011 and L012; Guide bar 10 is defined as the connecting rod L013 guide rod.

Create motion pair
Create a general method of kinematic pair: typically create a kinematic pair between two connecting rods; To collide in the movement of connecting rod, should create as a 3 dimensional contact vice, can appear otherwise simulation animation connecting rod phenomenon of mutual penetration, is inconsistent with the actual.The fixed connecting rod kinematic pair, can be without selecting the second connecting rod, UGNX is fixed it by default.Sports navigator of the connecting rod corresponding to the green words, kinematic pair corresponding to the orange icon on the right. As shown in Fig. 6

Automatic conveying and stamping machine with the holistic movement
As the rotation of the gear 3 will drive the rotation of gear 2, which drives the swinging rod 3 to move and swing, thereby making guide bar 13 to sliding,which can realize the function of conveying. After rotating a week later, the gear 3 will return to the starting position, to complete a cycle. As the rotation of the gear 3 will drive the rotation of gear 5, which drives the swinging rod 4 to move and swing, thereby making guide bar 10 to sliding, which can realize the function of stamping. After rotating a week later, the gear 3 will return to the starting position, to complete a cycle.

Automatic conveying and stamping machine of the kinematics simulation
Motion analysis is carried out in accordance with the input the time and the number of dynamic simulation analysis. Click the movement simulation animation icon, select a cycle as the research, the time set to 2 second, count to 500 steps, ADAMS solver after calculating, can directly see the simulation process of automatic conveying and stamping machine [7]. Because of the connecting rod can't for generating charts, selection of connecting rod L009 in conveying institution as a research object, aautomatically generated in the mapping function of time --displacement speed, time -acceleration diagram, as shown in Fig. 7 is the convey movement of the institution loop diagram; Selection of connecting rod L013 in stamping institution as a research object, automatically generated in the mapping mechanism of time --speed, time -displacement speed, and time--acceleration diagram, as shown in Fig 8 is  Choose connecting rod L009 and L013, automatic generation of its time --displacement diagram, as shown in Fig. 9. From Fig. 9 you can see the whole machine from 0 second began to move.0 second moment, conveying institution, located at 107.5 mm on workpiece, and at the same time stamping institution at the workpiece distance 280 mm, 0 to 0.5 second, conveying institution to push billet to processing position, stamping institution is quickly approaching billet.When 0.5 second moment, complete convey and return immediately. At the same time, stamping institution encounter blank, start to drawing the blank. 0 to 0.8 second, keeps uniform drawing stamping mechanism, conveying institution continue to stay away from the workpiece. 0.8 second moment, stamping institution to complete the drawing 0.8 to 1.2 second, stamping institution to continue downward movement, after drawing blank will launch processing position.The conveying institution continue to stay away from the workpiece 1.2 second moment, stamping institution will completely blank off a processing location, then immediately return. 1.2 to 2 second,stamping institution from processing position, and return to furthest distance artifacts in the 2 second moment distance is 280 mm.While conveying mechanism in 1.6 second moment reaches position for 200 mm, then immediately return back to the starting location, prepare for the next conveying .

Conclusion
In this paper, the accuracy of theoretical analysis is verified by modeling and simulation. The design of automatic conveying and stamping machine has the advantages of simple and compact structure and high matching precision. The motion simulation function of UGNX software, can dynamics and kinematics analysis to carry out on the body. The results show that this method can easily find out the cause of the failure in the operate, or sensitive factors, so as to take effective measures to ensure the normal operation of the automatic conveying and stamping machine.