Failure Analysis and Research of Washing Nozzle in Front of

Automobile

Guangming Li

1, 2

, Congrui Zuo

3, a, *

, Yi Ma

1, 2

and Qike Huang

1, 2

Department of Mechanical and Energy Engineering, Shaoyang University, Shaoyang 422000, China

Key Laboratory of Hunan Province for Efficient Power System and Intelligent Manufacturing, Shaoyang University,

Shaoyang 422000,China

Institute Of Thermal And Energy Metrology, Hunan Institute Of Metrology And Test ,Changsha 410000,China

Keywords: Front washing nozzle, Failure, Improved design, Finite element analysis.

Abstract: Xiangtan geely automobile production base, the author of this paper wiper washing system failure occurs,

the washing ball core fracture problem of the nozzle, combined with the actual production, based on product

failure reason analysis, found the ball core fracture basic appear in the winter, the temperature decrease after

the plastic shrinkage, the matching of the nozzle and the spool too tight, the user without the use of special

debugging tools debug copper ball, caused the ball core fracture, for this reason, put forward to increase

before initial washing nozzle spray Angle 6.5 o, and adjust the structure of the nozzle core ball, the ball core

from square to V groove root, enhance the strength of ball core groove, using the method of 3D modeling,

According to former car washing nozzle design parameters, through the Pro/E 3D software to complete

before washing nozzle and improving design of 3D model, using the finite element analysis of ANSYS

Workbench before washing nozzle improvement before and after the deformation and stress distribution, the

improved deformation from 0.0023643 mm to 0.0012954 mm, the improved maximum stress value from

472.87 MPa to 259.09 MPa, ultimate strength less than 300 MPa, improve the rationality of the design is

verified, for enterprises to solve the quality problem, have a very good reference value.

1 INTRODUCTION

Each major automobile giant has formed its own

characteristic wiper washing system, which has

advantages in reliability, economy or advanced

technology (Li guoqing, 2017). The investigation

found that xiangtan geely automobile production

base before the emergence of automobile washing

nozzle spray column spray problem, after inspection

for the ball core fracture. After investigation, during

the loading and production of this model, 7 front

nozzles were found to be broken when the injection

Angle was adjusted. According to the on-site

physical investigation and fault reproduction, it is

preliminarily determined that the interference

amount between the nozzle body and the ball head is

too large, leading to the fracture of the ball head

during adjustment (product consistency problem).

Interference fit is adopted between the nozzle body

and the ball head, and the interference amount is

0.05mm.

Figure 1. Nozzle regulating method.

Figure 2. Failure parts.

Li, G., Zuo, C., Ma, Y. and Huang, Q.

Failure Analysis and Research of Washing Nozzle in Front of Automobile.

DOI: 10.5220/0008867900590063

In Proceedings of 5th International Conference on Vehicle, Mechanical and Electrical Engineering (ICVMEE 2019), pages 59-63

ISBN: 978-989-758-412-1

After dismantling of the old parts and test

analysis, confirm the main failure reasons might be:

ball core fracture basic appear in the winter, the

temperature decrease after the plastic parts of a

contraction, the matching of the nozzle and the spool

too tight, the user without the use of special

debugging tools debug copper ball, caused the ball

core fracture, this problem has become a problem to

be solved in practical production, it has a strong

production of practical significance.

2 FAILURE ANALYSIS OF

AUTOMOBILE WASHING

NOZZLE

2.1 Present Situation Investigation and

Cause Analysis

After the dismantling and test analysis of the old

parts, it is confirmed that the main failure reasons

are as follows:

(1) The core fracture basically occurs in winter,

and the plastic parts shrink after the temperature

decreases in winter, which leads to the over-tight

cooperation between the core and the nozzle.

(2) The root of the nozzle center groove is

designed to be at right angles, and the strength is

insufficient. Besides, users do not use special tooling

for debugging, which results in the fracture of the

ball core.

(3) The spraying Angle of the nozzle has been

fully adjusted in the factory inspection, and our

company used special tooling for debugging,

without considering the possibility of some users

adjusting the Angle of the nozzle.

The diameter of the ball head of the nozzle of the

fault part is 4mm, which meets the design

requirement of 4.1mm. Therefore, the root cause of

the non-ball head fracture problem is the ball head

size. Shrinkage rate of nozzle body material PA6

and nozzle ball head material POM varies with

temperature, and the actual shrinkage of plastic parts

is related to material thickness, so it is difficult to

control the interference amount of 0.05mm by

adjusting injection molding parameters such as

injection pressure, pressure holding time and

temperature.

The shrinkage rate of nozzle body and ball head

material varies with the temperature. When the

temperature changes, the shrinkage rate of nozzle

body PA6 is larger than that of ball head bronze,

leading to the increase of interference amount and

the increase of regulating power. In view of the

above situation, according to the requirements of the

nozzle and the adjustment process of the nozzle

Angle, it is proposed to calibrate the initial injection

Angle of the former nozzle according to the laws

and regulations, and make adjustment tools

according to the calibration samples. The nozzle

Angle is adjusted before the nozzle leaves the

factory, so as to avoid the ball head breaking when

the assembly factory adjusts the nozzle Angle.

2.2 Automobile Front Washing Nozzle

Improvement Program

The demand for automobiles is very high, and the

output of automobile enterprises keeps climbing, and

the quality requirements of products are very high

(M. Unno, A, 2017). Improving the structure and

strength of washing nozzle is an effective method to

improve the quality of nozzle (Shao wei, 2016). The

improvement of the nozzle must meet the service

conditions and meet the requirements of contact

surface injection. According to the characteristics of

the nozzle model, the main improved parts focus on

the size and shape of the nozzle, so as to achieve the

improvement aimed at improving the nozzle strength.

Figure 3. Nozzle ball head diameter measurement data.

ICVMEE 2019 - 5th International Conference on Vehicle, Mechanical and Electrical Engineering

Figure 4. Nozzle Angle change diagram.

(1) It is required to increase the initial injection

Angle of the nozzle in the front nozzle, and its value

is 6.5o, as shown in FIG. 4.

(2) The current state of the nozzle is rectangular,

with low strength and concentrated stress at the root

of the groove. Therefore, adjust the structure of the

nozzle core, change the root of the core groove from

square to V-shaped, and enhance the strength of the

core groove. FIG. 5 is a brief comparison of the

nozzle before and after improvement.

To improve the former The improved

Figure 5. Schematic diagram of nozzle structure change.

3 STRUCTURAL ANALYSIS AND

IMPROVEMENT DESIGN

MODELING OF AUTOMOBILE

WASHING NOZZLE

3.1 Design Parameters of Pre-Wash

Nozzle

(1) Installation arrangement

In general, a number of nozzles should be

arranged on the annular pipe, which should be

arranged according to certain rules to ensure that all

surfaces can be covered by spraying materials, and

nozzles should be evenly distributed in the entire

spraying area (Shao gang, 2012). The distance

between the nozzle and the workpiece is required

that the workpiece should be in the area where the

liquid flows from the nozzle, so the layout between

the nozzle and the nozzle must follow a scientific

way. The distance between nozzles is usually

250mm to 300mm. When the two are misaligned,

the distance between the nozzle and the workpiece

should be greater than or equal to 250mm.

(2) Selection of nozzle profile size

The inner diameter of the nozzle ball core is

2mm ~ 3mm, the length of the nozzle is 2mm ~

5mm, the length of the body is 9mm~11mm, the

width of the body is 14mm~16mm, and the length of

the nozzle tube is 5mm~8mm.

(3) Radius of rounded corner of nozzle

The minimum radius of the nozzle is 2mm~4mm,

depending on the specific situation, some special

nozzle size will be slightly larger.

(4) Design angles on both sides of the nozzle

Generally used for cleaning function of the

nozzle, can choose a strong impact of the jet nozzle:

injection Angle generally 60° or so, this Angle

design, the nozzle has a larger impact force.

After measuring the pre-washing nozzle, the

main size data of the nozzle are shown in table 1.

Table 1. Main size data of nozzle (unit: mm).

Ball

core

diameter

Body

width

Body

length

Total

nozzle

height

15.3

9.5

33.2

3.2 The Establishment of the Model

before and after the Improvement

of the Former Washing Nozzle

3D software Pro/E was used to establish the model

before and after improvement of the ventilation pipe,

as shown in FIG. 6 and FIG. 7.

Figure 6. Improved previous nozzle model.

Figure 7. Improved nozzle model.

Failure Analysis and Research of Washing Nozzle in Front of Automobile

4 COMPARATIVE ANALYSIS OF

THE FINITE ELEMENT

STRUCTURE BEFORE AND

AFTER THE IMPROVEMENT

OF THE FORMER WASHING

NOZZLE

The finite element model material properties of the

pre-washing nozzle are shown in table 2 below.

Table 2. Nozzle material properties.

elasticity

modulus

(N/mm2)

poisson

ratio

density

(kg/m3)

load

(N)

ultimate

strength

(MPa)

105

0.25

7.45

300

4.1 Finite Element Analysis before the

Improvement of the Former

Washing Nozzle

Finite element analysis was conducted on the former

washing nozzle by ANSYS Workbench, and the

deformation amount and stress cloud diagram were

obtained as shown in figure 8 and figure 9

respectively.

Figure 8. Nozzle deformation before improvement.

Figure 9. Nozzle equivalent stress cloud diagram before

improvement.

According to the deformation amount in FIG. 8

and the front of the nozzle, the deformation amount

of the nozzle is not too large. It can be known that

the nozzle bottom has the maximum deformation,

which is 0.0023643mm. It can be seen from the

equivalent stress cloud diagram in FIG. 9 that no

supports at the bottom of the nozzle groove bear the

maximum stress, with the stress value of 472.87mpa

and the ultimate strength value of 300mpa.

Therefore, fracture occurs when non-special tooling

is used for adjustment. Combined with the damage

of automobile nozzles in actual working conditions,

the results of this analysis are consistent with the

actual situation of fracture failure of ball core of

automobile washing nozzles before xiangtan geely.

By observing the deformation diagram of the

nozzle, it can be seen that the nozzle bottom has

shifted. In order to solve the insufficient strength of

the nozzle, by improving the structure of the nozzle

bottom and adding chamfering, it is necessary to

check and analyze the improved model in the same

way to verify whether the stress value of the nozzle

meets the strength requirements of the nozzle.

4.2 Finite Element Analysis after the

Improvement of the Former

Washing Nozzle

Finite element analysis was conducted on the

improved nozzle by ANSYS Workbench, and the

deformation amount and stress cloud diagram were

obtained as shown in FIG. 10 and FIG. 11

respectively.

Figure 10. Improved nozzle deformation.

Figure 11. Improved nozzle stress cloud diagram.

According to the deformation amount in FIG. 10,

the maximum deformation of the nozzle groove

bottom is 0.0012954mm. According to the stress

cloud diagram in FIG. 11, the spray Angle of the

ICVMEE 2019 - 5th International Conference on Vehicle, Mechanical and Electrical Engineering

Table 3. Deformation and stress of washing nozzle before and after improvement.

Load

(N)

Deformation (mm)

Stress value (MPa)

before improvement

improved

before improvement

improved

0.0023643

0.0012954

472.87

259.09

nozzle is changed. The maximum stress is

259.09MPa after the chamfer is added to the bottom

of the "V" groove.

In summary, the displacement and stress values

before and after the nozzle improvement are

arranged as shown in table 3.

5 EFFECT OF VALIDATION

After the production base improves the structure of

the groove bottom of the front washing nozzle

according to the above scheme, the product batch is

switched, and no feedback on the fracture of the ball

head is received after the switch.

Effect verification:

1. Spraying effect: there is no obvious deviation

between the spraying effect and the change, as

shown in FIG. 12.

Figure 12. Improved nozzle stress cloud diagram.

2. Core strength:

(1) Before the change: use the clamp to clamp

the ball core, put the tool into the ball core slot,

forced rotation of the ball core fracture.

(2) After the change: clamp the ball core dead,

put the tool into the ball core slot, forced rotation of

the ball core did not appear broken.

6 SUMMARY

The main purpose of this paper is to find out the

reasons for the failure of washing nozzles in front of

cars and put forward improvement plans according

to the reasons of deformation. By using Pro/E

software for car washing nozzle before failure before

and after the improvement on 3 d modeling, using

the finite element ANSYS Workbench software of

finite element analysis was carried out on the car

before washing nozzle before and after improvement,

through the comparison and analysis of deformation

before and after the improved 0.0023643 mm and

0.0012954 mm, the stress value of 472.87 MPa and

259.09 MPa, verified the rationality of the nozzle

improvement program, in front of the car washing

nozzle optimal design has some reference meaning,

to improve the design quality, reduce design cost

and shorten the development cycle, It has good

engineering practical significance.

ACKNOWLEDGMENTS

Fund projects: outstanding youth project of

education department of hunan province (16B235),

general scientific research project of education

department of hunan province (17C1444 and

16C1432), and CX2016SY015 of postgraduate

scientific research innovation project of shaoyang

university

About the author: li guangming (1983-), male,

born in shaoyang, hunan province, master degree,

mainly engaged in vehicle engineering teaching and

research of automobile testing technology.

REFERENCES

Li guoqing. Principle analysis and comparison of

automotive wiper washing control system [J]. Light

vehicle technology, 2017 (09): 8-11.

M. Unno,A. Shibata,H. Yabuno,D. Yanagisawa,T. Nakano.

Analysis of the behavior of a wiper blade around the

reversal in consideration of dynamic and static friction

[J]. Journal of Sound and Vibration, 2017, 393.

Shao wei. Research on innovative design of automobile

wiper mechanism [J]. Modern manufacturing

technology and equipment, 2016 (01): 32-33..

Shao gang. Design of windshield wiper blade [J]. Journal

of anhui electronic and information vocational college,

2012, 11 (05):43-47.

Failure Analysis and Research of Washing Nozzle in Front of Automobile