JB/T 51128-1999
Single Cylinder Diesel Engine - Block - Product Quality Grading (Internal Use)
单缸柴油机 机体 产品质量分等（内部使用）
Catalogue
前言 → 1 范围 → 2 引用标准 → 3 质量指标 → 4 检验方法 → 5 检验规则 Foreword → 1 Scope → 2 Normative References → 3 Quality Indicators → 4 Inspection Methods → 5 Inspection Rules
Scope
This standard specifies the product quality indicators, inspection methods, and inspection rules for cast iron blocks of reciprocating single-cylinder diesel engines with cylinder diameters less than or equal to 200 mm (hereinafter referred to as blocks). This standard applies to the inspection and evaluation of the product quality of single-cylinder diesel engine blocks.
本标准规定了气缸直径小于或等于200 mm 的往复式单缸柴油机铸铁机体（以下简称机体）产品质量指标、检验方法、检验规则。本标准适用于单缸柴油机机体产品质量的检验和评定。
Normative References
Keywords
Application Summary AI generated
Manufacturers and quality inspection agencies of single-cylinder diesel engines use this standard to grade the quality of cast iron blocks. It helps ensure that blocks meet requirements in dimensional accuracy, material strength, and durability by setting specific indicators for qualified and first-grade products. This standard is crucial for ensuring the reliability and service life of complete diesel engines.
单缸柴油机制造商和质检机构使用本标准来评定铸铁机体的质量等级。它通过设定合格品和一等品的具体指标，帮助确保机体在尺寸精度、材料强度和耐久性方面达到要求。该标准对于保证柴油机整机的可靠性和使用寿命至关重要。
AI Summary AI generated
This standard applies to cast iron blocks of single-cylinder diesel engines with cylinder diameters ≤200 mm, specifying product quality indicators, inspection methods, and inspection rules. Blocks are graded as qualified or first-grade, requiring material not lower than HT200, with specific grading requirements for dimensional tolerances, geometric tolerances, surface roughness, casting defects, hydrostatic testing, and service life. Inspection methods cover tensile, hardness, dimensional, geometric, and visual checks. Sampling inspection follows GB/T 2828, with nonconformities classified into A, B, and C categories.
本标准适用于气缸直径≤200mm的单缸柴油机铸铁机体，规定了产品质量指标、检验方法和检验规则。机体按质量分为合格品和一等品，要求材质不低于HT200，并对尺寸公差、形位公差、表面粗糙度、铸造缺陷、水压试验及使用寿命等提出具体分等要求。检验方法涵盖拉伸、硬度、尺寸、形位公差及外观等，抽样检验按GB/T 2828进行，不合格分为A、B、C三类。
Key Sentences extracted from text
本标准规定了气缸直径小于或等于200 mm 的往复式单缸柴油机铸铁机体（以下简称机体）产品质量指标、检验方法、检验规则。
机体产品按其不同质量指标分为合格品、一等品两个等级。
机体产品材质应不低于GB/T 9439—1988 规定的HT200 牌号。
机体不允许有裂纹、浇不足、严重粘砂以及其他降低机体结构强度或影响切削加工和铸件定位夹紧的铸造缺陷。
机体应经水压试验无渗漏。
This standard specifies the product quality indicators, inspection methods, and inspection rules for cast iron blocks of reciprocating single-cylinder diesel engines with cylinder diameters less than or equal to 200 mm (hereinafter referred to as blocks).
Block products are divided into two grades: qualified product and first-grade product, according to their different quality indicators.
The material of the block product shall not be lower than the HT200 grade specified in GB/T 9439—1988.
The block shall not have casting defects such as cracks, misrun, severe sand adhesion, or other defects that reduce the structural strength of the block or affect machining and positioning/clamping of the casting.
The block shall undergo a water pressure test without leakage.
Standard Timeline
Changes from replaced version:
- 仅对原标准作了编辑性修改，主要技术内容没有变化
- Only editorial modifications were made to the original standard; the main technical content remains unchanged.