GB/T 19724-2020Forestry machinery - Portable chainsaws and brush-cutters - Exhaust system-caused fire risk (English PDF)

Foreword

This standard was drafted in accordance with the rules given in GB/T 1.1-2009.

This standard replaces GB 19724-2005 "Forestry Machinery Portable Chainsaw and Brush Cutting Machine Easily Causes Fire Risk Emission System"

Compared with the main technical content of GB 19724-2005, there is no change except for ISO 9467..1993.

Sub-content.

The translation method used in this standard is equivalent to the use of ISO 9467..1993

System ".

The documents in China that have a consistent correspondence with the normatively cited international documents in this standard are as follows.

--- LY/T 1593-2001 Portable chain saw engine performance and fuel consumption (eqvISO 7293..1997)

--- LY/T 3165-2019 Forestry machinery portable brush cutter and lawn mower engine performance and fuel consumption (ISO 8893.

1997, IDT)

Please note that some content of this document may involve patents. The issuer of this document does not assume responsibility for identifying these patents.

This standard was proposed by the State Forestry and Grassland Bureau.

This standard is under the jurisdiction of the National Forestry Machinery Standardization Technical Committee (SAC/TC61).

This standard was drafted by. Shandong Huasheng Zhongtian Machinery Group Co., Ltd., National Forestry and Grassland Bureau Harbin Forestry Machinery Research

Institute, Zhejiang Yate Electric Co., Ltd., Zhejiang Yusen Bailian Tools Co., Ltd., Zhejiang Zhongma Garden Machinery Co., Ltd., Zhejiang Zhongjian Branch

Technology Co., Ltd., Zhejiang Sanfeng Industrial Co., Ltd., Zhejiang Pineier Technology Co., Ltd., Yongkang Power Technology Co., Ltd.

the company.

Introduction

During the dry season, using engine-powered equipment such as chain saws and brush cutters may cause forest fires. Chainsaw

Or the exhaust system of the brush cutter has three potential fire hazards for dry plants. 1) overheated exhaust gas; 2) overheated exhaust system

The surface of the system; 3) The carbon particles discharged in the burning state. The occurrence of fire risk depends on the specific plants encountered, environmental factors, chain saws or brush irrigation

There are many factors such as the way the machine is used, the size of the carbon particles emitted, and the temperature of the exhaust gas and the surface of the exhaust system.

Forestry machinery portable chain saw and brush cutter

Emission systems that are liable to cause fire risks

1 Scope

This standard stipulates the technical requirements and test methods of the fire-prone discharge system in portable chain saws and brush cutters.

Technical requirements include.

--- The maximum temperature of the exhaust gas and the surface of the exhaust system;

--- The maximum aperture size of the screen-type Mars suppressor;

--- Restrictions on sediments;

--- Durability and reliability requirements.

Test methods include.

--- Test methods for exhaust gas and exhaust system surface temperature;

--- The determination method of the size of the screen mesh Mars suppressor.

Note. Except for screen-type Mars suppressors, this standard does not specify a method for measuring the limit size of carbon particles in emissions.

2 Normative references

The following documents are essential for the application of this document. For dated references, only the dated version applies to this article

Pieces. For the cited documents without date, the latest version (including all amendments) applies to this document.

ISO 7293 Forestry machinery portable chain saw engine performance and fuel consumption (Forestrymachinery-Portablechain

saws-Engineperformanceandfuelconsumption)

ISO 8893 forestry machinery portable brush cutter and lawn mower engine performance and fuel consumption (Forestrymachinery-

Portablebrush-cuttersandgrass-trimmers-Engineperformanceandfuelconsumption)

3 Terms and definitions

The following terms and definitions apply to this document.

3.1

Exhaust system

Exhaust gas flows from the exhaust port of the cylinder to all components that flow into the air, including all overheated surface protection components.

3.2

Power head

For chain saw refers to the remaining part after removing the guide plate and saw chain; for brush cutter refers to the removal of the drive shaft assembly and cutting accessories or other removable

After installing the additional parts.

3.3

Contact plane

An imaginary plane defined by at least three points touching the end of the power head (see 6.2).