Multi-functional cutting cutter design

Abstract: through the working principle of the cutting machine, classification, combined with the mainstream 3 d design software Pro / E of the cutting machine product parts modeling, through the software to provide virtual assembly and mechanism motion simulation environment, in the need to invest money manufacturing, the design of the overall structure analysis, appearance design, structure optimization design of traditional design methods, cannot realize the operation, and the use of drawing conversion function will design parts generated two-dimensional engineering drawings.

 Keywords: vegetable cutting machine; virtual assembly; motion simulation; Pro / E;

At any time, the design and development of new products cannot be separated from the market demand. With the continuous acceleration of the pace of life, people’s life pressure is also gradually increasing. How to help people better adapt to the current fast-paced life is the responsibility and obligation of every product designer. This design is close to life, focusing on the dangerous housework of cutting vegetables, and puts forward the design scheme of household vegetable cutting machine, mainly helping people solve the common cutting work of root and block vegetables in life, help people get rid of the dangerous work of cutting vegetables, and improve people’s quality of life in a fast-paced environment.

1 Overview of the development of cutting cutter

Vegetable cutting machine, a kind of food machinery and equipment that pretreatment food raw materials. Its working process is to use the shear principle to cut off or chop food raw materials, through the relative movement between the material and the cutting knife to complete. The object of the cutting machine is vegetables, and the shape and specification after processing are different from the cutting machinery, which is a kind of special mechanical equipment.

1.1 Classification of vegetable cutting machine

 On the market the existing cutting principle of vegetable processing is mainly through the simulated manual cutting, through the transmission belt vegetables uniform to the fixed direction, tool reciprocating movement in the vertical direction, so as to realize the cutting purpose of vegetables, the cutting machine can control the feed speed and the frequency of tool reciprocating movement to meet the requirements of different cutting. This kind of cutting machine is large, high efficiency, energy consumption, mainly used to meet the use of large food processing plants or large canteen and other places with large demand.

 According to the function is mainly divided into two categories: single-cut type and multi-function vegetable cutting machine.

Single cutting machine is suitable for the cutting of slices, segments, silk, tubers and leaf vegetables. It is generally used in food processing plants for special aircraft, such as potato cutting machine, which can improve the production efficiency of products. The typical structure is the box-type type.

On the basis of single cutting type, the multi-function cutting machine integrates the cutting functions such as slices and silk, and at the same time can process different types of vegetable circles, enriching the processing object of the product. This kind of vegetable cutting machine is mostly used in large restaurants and other places. Multi-function cutting cutter can be divided into two categories according to the structure:

 Double-headed vegetable cutter:

One end of the cut leaf vegetables, cut by the conveyor belt, reciprocating tool cutting; the other end of the cut potatoes and other roots, block vegetables, the raw material from the inclined material cylinder, cut by the rotary tool, can work at the same time, by replacing the knife plate, various specifications of pieces, silk, strip can be cut.

 Combined cutting cutter:

The horizontal conveyor belt transmits raw materials, cut by a number of tools distributed at a certain Angle on the conveyor belt, and formed after the raw materials through one or more cuts on the conveyor belt. The shape parameters of the finished product are controlled by adjusting the cutting speed of the tool and the transmission speed of the raw materials.

1.2 Development trend of cutting cutter

Through the observation of the cutting machine in the market, the comparative analysis of its structure and function found that the development of the cutting machine mainly tends to the following two characteristics:

(1) Functional integration

At the same time of ensuring the basic functions, with the structural modification and optimization, the functions of different products, to achieve the multi-use of one machine, improve the use value of the product, reduce the cost of the product. Similar to the integration of soybean milk machine and juicer, it not only reduces the cost of consumers, but also improves the market competitiveness of the products.

(2) Specification and polarization

Vegetable cutting machine is a kind of vegetable processing machinery, and its scope of application varies by location. Large-scale food processing plants and hotels need high efficiency, fully automatic cutting machine equipment, and the requirements for its processing effect will continue to improve. However, with the improvement of living standards, people’s comfort requirements for family life are also improving, the demand for household cutting machine will continue to increase, simple operation, light fashion, diverse functions of household cutting machine products will be warmly welcomed by the market.

1.3 Original parameters of the cutting cutter

 The design scheme of the vegetable cutting machine proposed in this paper mainly deals with the common root and block vegetables in daily life, and the main design parameters originate from the experimental measurements of different vegetables.

Table 1 is listed in the-1 for potatoes, yam, carrots, white radish and lotus root the five kinds of vegetables cutting force determination results, this experiment is the family life, cutting tools choose ordinary household fruit knife, vertical cutting at the largest diameter, and measured by the maximum weight of cutting, and then through the data conversion to different vegetables cutting approximate cutting force.

Table 1-1 Determination of vegetable cutting force

Vegetable species	Vegetable characteristics		cutting force (N)				Cutting force maximum (N)
	Maximum diameter	conduct oneself with dignity g	1	2	3	4
murphy	56	200	30.87	40.57	40.28	37.73	40.57
Chinese yam	62	240	10.34	11.17	10.00	10.68	11.17
Daucus carota	30	70	43.51	46.35	46.45	46.06	46.45
ternip	78	320	23.33	20.8	16.27	16.46	23.33
lotus root	68	140	72.13	65.76	56.54	59.68	72.13

 Through the analysis of the measurement results in Table Table 1-1, the maximum cutting force of the lotus root is selected as the reference of this design, and the cutting force of the design parameters is determined to be 90N by comprehensively considering the shape of the raw materials and the measurement accuracy. Considering the large difference in the shape of block vegetables, the maximum processing diameter of this design is limited to 80mm. According to the different size requirements of cooking ingredients, the thickness of the cut slice can be adjusted within 3-10mm, and the filarial vegetables that can be processed are divided into two kinds of thickness.

According to the living habits of most families, the working time of the cutting machine is determined as: 10 years, 360 days / year, 2 times / day, each work 0.4h. The design adopts the national standard product design standards, energy saving and environmental protection, safe use, convenient maintenance.

2. Principle and scheme design

2.1 Scheme design

 Different from the existing vegetable cutting machine products on the market now, its small size, light quality, simple operation, and to integrate fashion factors, easy to clean, etc. Through the analysis of the design scheme of the existing vegetable cutting machine, the design scheme of this design is put forward:

 Place the vegetable in the vertical or upward inclined material cylinder, rely on the gravity of the vegetable or apply external force to the vegetable, and the tool can realize the vegetable processing function by changing different types of tools; design the container under the tool and collect the processed vegetables with the center of gravity or centrifugal force.

Design cutting machine reduces the conveyor belt structure, make the product overall space, and through rotating cutting can not consider the root, block vegetables irregular appearance, can get good cutting effect, and power using human or motor, only need to design reasonable pressure mechanism can meet the design requirements.

2.2 Structural design

 The overall structure layout of the product can be divided into horizontal and vertical types. The two structures are analyzed as follows:

 

• •  Horizontal layout: at present, the most common layout form, in the horizontal direction, the sequential layout of the power mechanism, transmission mechanism, cutting mechanism, and finally the material cylinder. The tool rotates in the vertical plane, and after the vegetables are put into the material cylinder, the dead weight moves down along the cylinder wall. The processed vegetables fall into the collection container located under the tool under the action of dead weight and centrifugal force. The main advantages are the horizontal layout of the scattered force, stable structure, the independence of each mechanism is good. The disadvantage is that the position of the material cylinder is fixed, and it is not easy to collect the classification of vegetables, which occupies more space compared with the vertical layout.

• •  Vertical layout: the pressure supply mechanism, material cylinder, cutting mechanism, transmission mechanism and power mechanism are arranged in the vertical direction, in which the transmission mechanism and power mechanism can be arranged in parallel. The advantages of vertical layout are that the material cylinder is arranged vertically, which occupies small space, multiple feeding ports can be arranged on the rotating path of the tool, and the movement of vegetables is always vertical downward, the work of each material cylinder will not interfere with each other. The disadvantages are more obvious, the vertical layout structure is relatively concentrated, and the strength of the support mechanism is relatively high requirements.

Through the comparative analysis of the two layout forms, combined with the design requirements of the household cutting machine, comprehensive consideration, decided to choose the vertical layout form to design the household cutting machine.

2.3, and a schematic diagram

To summarize the above analysis results, the working diagram of this vegetable cutter is simplified as shown in Figure 2-1.

Figure 2-1 Schematic diagram of the vegetable cutting machine

3. Structural design of the main components

3.1 Parameter calculation

The original parameters know the maximum cutting force when completing the cutting: F=90N, working time: 10 years, 360 days / year, 2 times / day, each work 0.4h, the speed of the motor: 120 r/min, using vertical layout, directly connect the motor shaft with the tool.

The total power required for the cutter can be calculated from the above data:

 Among them: – -the working power required by the vegetable cutting machine, W;

– -Total efficiency of motor spindle to vegetable cutter cutter shaft.

Operating power required for the vegetable cutter:

Among them: the working resistance of F- -cutting machine, namely the maximum cutting force, N;

V- -the line speed of the vegetable cutter, m/s;

N- -Speed of vegetable cutter, r/min;

R-cutting force radius of cutting, mm;

The total efficiency of the transmission device is the product of the motion efficiency of each part of the transmission device, which is the transmission efficiency of the motor bearing in this design:

Where: for the bearing forehead transmission efficiency, then

Preliminary design R=80mm, then it can be calculated as:

Input torque of the spindle:

Table 3-1 Results of motion and dynamic parameters

Axis name	productiveness P()		torque T()
	import	output	import	output
motor shaft	115.35	113.04	9.18	9.02

Combined with the above calculation results, according to the working environment of the cutting machine and the power conditions of the family, select the vertical closed DC motor with rated voltage of 220V, rated power of 120W and speed of 120 r/min. Considering the overall assembly requirements of the cutting machine, the motor shaft length is L=250mm, and the length of the protruding part is 180mm. Based on the understanding of the parameters of the motor in the market and the utilization of network resources, the permanent magnet DC motor produced by Shenzhen Longwei Industrial Co., LTD. is selected as LRS-7512 SHP-2080-160M. Motor parameters are shown in Table 3-2 main parameters of the motor, and its main dimensions are shown in Figure 3-1 LRS-7512 SHP type motor.

Table 3-2 Main parameters of the motor

model	rated voltage	power rating	Load parameters		quality Kg
			speed r/min	moment N.m
LRS-7512SHP	220V	120W	120	25	0.5

Fig. 3-1 Main shape and dimensions of LRS-7512 SHP type motor

3.2 Design and check of the knife shaft structure

3.2.1 Structural design of the knife shaft

According to the blade installation mode and assembly requirements, the structure of the knife shaft is designed as shown in Figure 3-2.

Structural dimension diagram of Figure 3-2 axis

The knife shaft shaft diameter can be determined in the following type:

Where: – -axis transmission power, kw;

– -Speed of the shaft, r/min;

– -Material coefficient;

According to the requirements of GB9684-88, the Sanitary Standard, the material of selecting the motor shaft is SUS304, namely 1Cr19Ni9. Check [1] Table 15-3;

 Then the diameter of the axis is:

Considering the flat structure and thread of the axis end, enlarge the axis diameter by 15% to ensure the strength of the axis, then the minimum diameter of the axis should be d=(1+15%)×7.84=9.016mm and set d to 10mm.

3.2.2 Tool shaft strength check

According to the working principle of the cutting machine, it is known that this shaft is only subject to a small bending moment, so it only needs to check according to the torsion strength, and check the [1] type (15-1):

Where: – -Torsional shear stress, MPa;

– -Torque received by the shaft,;

– -Torsional cross-section coefficient of the shaft,;

– -allowable torsional stress, MPa;

The danger section of the shaft at the shaft end is shown in the danger section of axis 3-3:

Figure 3-Hazard section of axis 3

Check the calculation formula of table [1] (15-4) for the bending and torsion section coefficient, and know that the calculation formula of the torsion section coefficient of the danger section is:

From Figure 4-4, d=10, b=7.1, t=1.5 substitution:

 There are:

This result shows that the shaft strength design meets the requirements.

3.2.3 Tool shaft stiffness check

According to the working principle of the cutting machine, it is known that the bending deformation of this axis is very small, so the axis stiffness is only checked according to the torsional stiffness of the axis. The calculation formula for checking the torsional stiffness of the optical axis of formula [1] (15-15) is:

Where: – -The torque subjected to the shaft,;

– -The shear elastic modulus of the material of the shaft,, for steel,;

– -Polar moment of inertia of the axis section, for the circular axis,; take here;

There are:;

 Will bring into the:

So this axis meets the stiffness requirements.

3.3 Design of cutting parts

 As the actuator of this design, the cutting mechanism is the key part of this design, which should not only consider the use performance, but also the safety of the material and the cleaning of the product after use. For safety reasons, the components must choose pollution-free rust materials, but also attention should be paid to the cutting components and electrical components to reduce the possibility of raw material pollution.

As is known to all, root and block vegetables are not only irregular in shape, but also difficult to cut. Combined with experimental measurement and fruit, the cutting blade in this design adopts smooth blade plate knife as slicing knife, and comb blade blade is selected for cutting. Blade material combined with GB9684-88 “stainless steel food container sanitary standard” requirements of austenitic stainless steel (1Cr18Ni9Ti, 0Cr19Ni9,1Cr18Ni9), to determine the cutter blade material is 0Cr19Ni9, that is, often said SUS304 steel.

 Because to realize the conversion from the tool, so consider the blade from the blade, by replacing different blades to realize the conversion, while the knife process must be simple and easy to operate, comprehensive considering the knife frame structure design as shown in figure 3-4, design three blade installation slot, using the hexagonal screw under the tool, in the need to change the tool under the cabbage container, the fixed blade hexagonal screw release, can remove the blade from the side, so not only realizes the slice cutting function, but also reduce the time of the knife.

While realizing the function of slice cutting, we should also consider the different requirements for slice thickness. In this design, a certain space is reserved between the knife holder and the blade, and the cutting thickness of the blade is adjusted by increasing or reducing the cushion plate between the blade and the blade holder, so as to realize the function of cutting thickness control. The specific situation is shown in Figure 3-5.

Figure 3-5, knife holder structure

4 Application of the 3 D design software based on Pro / e

 With the development and progress of computer technology, computer-aided design technology has shifted from the two-dimensional design level of CAD to three-dimensional solid design. At present, three-dimensional design software has been widely used in machinery, electronics, aerospace, construction and other industries. The design advantages of 3 d modeling greatly shorten the cycle of product research and development and design, reduce the labor intensity of designers, and also realize the establishment of the standard library of similar parts, which greatly facilitates the technical exchange between similar industries.

The cutting machine design adopts the 3 D design software Pro / e developed by PTC Boston, all the products in 3 D modeling, virtual assembly, assembly simulation, assembly animation, interference inspection and other work, Simulate the product assembly process through the virtual assembly, Interference inspection can enable inspection of virtually assembled products, Found the assembly interference between components, Mechanism simulation can truly understand the working situation of the product, Assembly animation can simulate the real assembly effects, Through the application of the software, Not only reduces the work pressure of the designer, It also saves the design cost, Accelerate the product design cycle and product design quality.

4.1 Virtual assembly

4.2 The explosion view

 

4.3 Interference inspection

After the virtual assembly and explosion view, we do not guarantee the parts in the process of assembly of no interference between each other, if the blind manufacturing material, may cause unnecessary waste, in order to avoid this problem, we can in the Pro / e assembly environment, the assembled parts, to ensure that the parts with the correct size, the assembly between the parts. The operation method for interference inspection of the assembled components is as follows: Click Analysis-Model-Global Interference command, and select Include Face Group, Include Small planes, and Exact in the Global Interference dialog box to conduct interference inspection of the completed assembly components. Using this method, the interference inspection results of the vegetable cutter involved are as follows:

6 Summary

(1) the design through the understanding of the existing cutting machine, put forward a new household cutting machine design, household cutting machine design not only enrich the types of household food machinery, at the same time fill the blank of the domestic household cutting machine market, in home cutting machine product direction has a lot of research space, should be further research, realize the function of a multi-purpose machine.

(2) through the use of Pro / e 3 d design software, familiar with the process through the product design of 3 d design software and 3 d software design advantages, and the virtual assembly, motion simulation operation, not only enrich the 3 d design software in the application of food machinery product design, at the same time for computer-aided design 3 d software design technology further research lay the foundation.

reference documentation

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[2] Tian Weijun. Based on the Pro / E mechanical design example, precision solution [M]. Beijing: Beijing Aerospace University Press, 2009.1;

[3] Shan Quan, Chen Yan, Wang Dianlong. Pro / ENGINEER Wildfire 4.0 Chinese version of the parametric design from introduction to master [M].

Beijing: Higher Education Press, 2007;

[4] Xue Ming Zhai Computer Education Research Office. Pro / Engineer wildfire version mechanism simulation motion example intensive lecture. Beijing: People’s Posts and telecommunications

Press, 2008.5;

[5] Jiang Diqing, Tang Weiqiang. Food General Machinery and Equipment [TS]. Beijing: National Defense Industry Press, 2005;

[6] Li Changlin, Bai Qiao, Xiang Huiyu, Luo Hongqi. Pro / e parametric technology in the design of general parts of food machinery

need [J]. Beijing: Packaging and Food Machinery, Volume 29, No.6,2011;

Design of multi function cutting machine

Liu Cheng Yang  Zhang Zhan Ling

(Department of Mechanical Engineering , Zhengzhou College of Science &Technology , Zhengzhou 450064 , China)

Abstra ct: The working principle, the cutting machine classification learning, combined with the current mainstream 3d design software Pro/E for modeling cutting machine product design components, software through the virtual assembly and simulation environment, do not need to invest money in real situation, analysis, design, traditional design method structure optimization design can not achieve the overall structure of the operation on the design of the product, drawing parts of generating 2D drawing conversion function and using the designed.

Keywords: machine Qiecai; 3D modeling; virtual assembly; mechanism simulation;