Structural optimization of gauge apron and investigation on microfoam products

doi:10.19491/j.issn.1001-9278.2025.04.011

Abstract

Abstract:

The WJ⁃8 type fastening system is mainly used for high⁃speed railway tracks， and the gauge baffle is an important component of the WJ⁃8 type fastening system. This gauge baffle plays an important role in transmitting loads， maintaining and adjusting the gauge of two rails， and it also has a certain insulation in the fastening system. At present， the gauge baffle is produced using an ordinary injection molding technology， which makes the product prone to shrinkage， and the elastic strip buckle is prone to crushing during use. This article mainly optimized the structure of the gauge baffle and produced the corresponding products by selecting suitable foaming agents for tests to meet the performance requirements. The problems of shrinkage and pressure feedback at the clamping point of the track gauge baffle product was solved. This study provides an important reference for better engineering applications in the future.

Key words: gauge apron, insulation, microfoam

CLC Number:

TQ320.72

YAN Xiang, DENG Jiao, LIU Wei. Structural optimization of gauge apron and investigation on microfoam products[J]. China Plastics, 2025, 39(4): 59-63.

Figures/Tables 20

Fig.1. Gauge apron

Fig.2. Enlargement and deepening of grooves

Fig.3. Back structure

Fig.4. Structural strengthening of abutment

Fig.5. Reinforcement of support foot

Fig.6. Loading status of gauge apron

Fig.7. Displacement nephogram of new and old structure of gauge apron

Fig.8. Cross⁃sectional stress nephogram of spring buckle of new and old structure of gauge apron

Fig.9. SEM of cross⁃section of sample without foaming agent

Fig.10. SEM of foam cell morphology of sample with added foaming agent

检验项目	检验方法	微发泡检测结果	传统工艺检测结果
拉伸强度/MPa	GB/T 1447	165.6	181.5
弯曲强度/MPa	GB/T 1449	220.7	265.3
简支梁无缺口冲击强度/kJ·m^-3	GB/T 1043	115.837	118.953
简支梁缺口冲击强度/kJ·m^-3	GB/T 1043	25.539	26.385

Tab.1. Comparison of mechanical properties between GFPA66 micro foaming process and traditional injection molding process materials

Fig.11. Time comparison between microfoamin injection molding process and conventional injection molding process

发泡剂含量	1.5 %	2 %	2.5 %
样品截面
缩孔结构	粗孔均匀分布	粗孔非均匀分布	粗孔均匀分布
孔径/mm	0.57	0.36	0.41

Tab.2. Cross⁃section of products adding TRACEL IM 3235 foaming agent

发泡剂含量	0.3 %	0.9 %	1.5 %
样品截面
缩孔结构	粗孔均匀分布	粗孔均匀分布	粗孔均匀分布
孔径/mm	0.26	0.15	0.09

Tab.3. Cross⁃section of products adding NUC C 20 foaming agent

发泡剂含量	1 %	2 %	3 %
样品截面
缩孔结构	粗孔均匀分布	粗孔均匀分布	粗孔均匀分布
孔径/mm	0.55	0.32	0.20

Tab. 4. Cross⁃section of products adding CORDUCELL EX 9824 foaming agent

发泡剂含量	2 %	3 %	4 %
样品截面
缩孔结构	细孔均匀分布	细孔均匀分布	细孔均匀分布
孔径/mm	0.06	0.06	0.06

Tab.5. Cross⁃section of products adding HYDROCEROL 592 foaming agent

Fig.12. Inspection of shrinkage hole in gauge apron

Fig.13. Fatigue test of gauge apron assembly

检验项点	技术要求	实测结果	检测手段	结论
检验项点	技术要求	实测结果	检测手段	Y	N
绝缘电阻	>5×10⁶Ω	6.0⁃7.2×10⁷Ω	高阻计	Y
洛氏硬度	≥105HRR	112⁃114HRR	洛氏硬度计	Y
抗压强度	（70KN，3次）产品未破坏	未破坏	试验机/塞尺	Y

Tab.6. Physical properties of gauge apron

Fig.14. Samples after 8 million fatigues

References 15

1	田炳彬.高速铁路轨枕及扣件加载试验系统研究［J］.中国科技信息， 2012（23）：113⁃114.
	TIAN B B. Systematic research on high⁃speed rail sleepers and fastenings testing［J］. China Science and Technology Information， 2012（23）：113⁃114.
2	肖俊恒.客运专线无砟轨道扣件系统技术研究［J］.中国铁路， 2009（2）：44⁃47.
	XIAO J H. Research on the technology of ballastless track fastening system for passenger dedicated lines ［J］. Chinese Railways， 2009 （2）： 44⁃47.
3	石波，刘斌.注射成型过程中制品质量的控制研究现状分析［J］.塑料工业， 2012， 40（10）：9⁃13.
	SHI B， LIU B. Analysis of present research on product quality control in the injection molding process ［J］. China Plastics Industry， 2012， 40 （10）： 9⁃13.
4	Agrawal A R， Pelidis I O， Pecht M. Injection⁃molding process control⁃a review［J］. Polymer Engineering & Science， 2010， 27（18）：1 345⁃1 357.
5	李金良.注射成型短射缺陷分析及处理［J］.中国科技博览， 2013（11）：24.
	LI J L. Analysis and treatment of short shot defects in injection molding ［J］. China Science and Technology Expo， 2013 （11）： 24.
6	SHU N P. Innovation in polymer processing［J］. Cincinnati，1996.3：93⁃149.
7	赵正创，欧阳春发，相旭，等. 微发泡聚合物材料的研究进展［J］.化工进展， 2016， 35（1）：209⁃214.
	ZHAO Z C， OUYANG C F， XIANG X， et al. Reseach progress in microcellular polymer material ［J］. Chemical Industry and Engineering Progress， 2016， 35 （1）： 209⁃214.
8	黄为群，黄学彬，陈勇，等.高速铁路用膨胀型微发泡垫板的制备和应用［J］. 塑料，2010， 39（5）：106⁃110.
	HUANG W Q， HUANG X B， CHEN Y， et al. Manufacture and application of micro⁃foaming railroad sleeper used for high⁃speed railway ［J］. Plastics， 2010， 39 （5）： 106⁃110.
9	鲍泉，何继敏，薛平，等.纤维增强发泡复合材料中纤维与发泡关系的研究进展［J］. 塑料工业，2017， 45 （4）：1⁃4.
	BAO Q， HE J M， XUE P， et al. Research progress of the relationship between fiber and foaming in fiber reinforced foamed composites［J］. China Plastics Industry， 2017， 45 （4）： 1⁃4.
10	何海，邱启航，何力，等. GF增强母粒对微发泡PP/GF复合材料力学性能的影响［J］.塑料科技，2013，41（9）：47⁃51.
	HE H， QIN Q H， HE L， et al. Effect of GF reinforced masterbatch on mechanical performances of microcellur foam PP/GF composites［J］. Plastics Science and Technology， 2013， 41 （9）： 47⁃51.
11	赵顺强，常杰，仇鹏，等.注射成型工艺对高铁轨距挡板稳定性影响［J］. 工程塑料应用， 2021，49（11）：89⁃94.
	ZHAO S Q， CHANG J， QIN P， et al. Influence of injection molding process on stability of high⁃speed railway Gauge Baffle［J］. Engineering Plastics Application， 2021， 49（11）： 89⁃94.
12	鲍星旭.高速铁路WJ-8型扣件轨距挡板注塑模具设计［J］.铁道技术监督， 2020， 48（7）：45⁃49.
	BAO X X. Design of injection mold for WJ-8 fastener gauge baffle of high⁃speed railway［J］. Railway Quality Control， 2020， 48（7）： 45⁃49.
13	覃宇航，吴国洪，梅琼风，等. 玻纤增强微发泡注塑成型制品等效弹性矩阵的计算［J］. 模具技术， 2016（3）：7⁃10.
	QIN Y H， WU G H， MEI Q F， et al. Analysis of equivalent elastic properties of glass fiber reinforced microcellular injection molded parts［J］. Die and Mould Technology， 2016（3）： 7⁃10.
14	国家铁路局. 高速铁路扣件第5部分：WJ⁃8型扣件：［S］. 北京：中国铁道出版社，2015.
15	国家铁路局. 高速铁路扣件系统试验方法第4部分：组装疲劳性能试验：［S］. 北京：中国铁道出版社，2015.

[1]	. Structural optimization of gauge apron and investigation on microfoam products [J]. , 2025, 39(5): 59-63.
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[14]	. Study on Thermal Conductivity of Thermal Insulative Composites of PA6 Filled with BN Particles [J]. China Plastics, 2015, 29(03): 21-25 .
[15]	Xin-Qiang YUAN . Investigation on Fire Retardant and Heat Insulation Performance of PMMA/Fly Ash/Mg(OH)₂ Composite [J]. China Plastics, 2014, 28(01): 84-87 .