月: 2022年12月

What Is a Tangless Insert?

A tangless insert is a type of insert screw (female thread reinforcement, reinforcement part) that lacks tangs.

Conventional insert screws feature tangs that need to be removed after being inserted into the female thread for reinforcement. The absence of tangs in tangless inserts leads to various cost reductions and a significant decrease in defects caused by the insertion process.

Uses of Tangless Inserts

Tangless inserts are used to reinforce female threads. They are inserted using a specialized tool that grips the inserts with its jaws. To insert a tangless insert, a hole is drilled in the light metal or resin intended for the female thread, and the insert is rotated into place. These inserts can be easily removed by using the tool to turn them in the opposite direction of insertion.

Features of Tangless Inserts

1. No Need to Remove Tangs: Traditional insert screws come with tangs that must be removed after insertion. These removed tangs can become mixed with equipment, potentially causing malfunctions.
2. No Directionality: Tangless inserts lack directional characteristics, which eliminates the need to check the orientation of tangs during insertion. This reduces the time required for insertion.
3. No Damage to Base Metal: The ease of insertion and removal of tangless inserts minimizes the risk of damaging the base material where the insert is placed.

What Is a Gas Flow Measurement System?

A gas flow measurement system is a device designed to measure gases with specific properties present in the air.

These gases include flammable, toxic, inert, and combustible gases. Gas flow measurement systems are crucial for detecting gases that pose direct dangers to humans or are potentially flammable.

Various measurement methods exist, tailored to the gas’s specific characteristics. These include devices that leverage optical properties and those measuring physical properties.

Applications of Gas Flow Measurement Systems

Gas flow measurement systems are vital for detecting leaked flammable or toxic gases in the atmosphere and measuring their concentrations. Since these gases are often colorless and undetectable by humans, they can pose significant risks. Common devices include methane, carbon monoxide, and carbon dioxide measuring instruments.

These instruments are designed to measure gas concentrations continuously, as well as short-term and long-term cumulative concentrations. It is essential to select a method that accurately detects the target gas’s concentration without interference from other gases.

Types of Gas Flow Measurement Systems

Gas flow measurement systems are categorized into solid-state sensors, electrochemical sensors, and optical sensors.

1. Solid-State Sensor

Examples of solid-state sensor technologies include the catalytic combustion method, new ceramic method, semiconductor method, hot wire semiconductor method, and thermoelectric method.

2. Electrochemical Sensor

Electrochemical sensors utilize techniques such as the constant potential electric field method, diaphragm-separated constant potential electric field method, diaphragm electrode method, and diaphragm galvanic cell method.

3. Optical Sensor

Optical sensors employ methods like the infrared method, detection tape method, and thermal particle method.

Structure of Gas Measuring Systems

Catalytic combustion sensors measure combustible gas concentrations by utilizing the heat generated during combustion, with changes in the resistance of a platinum wire coil indicating gas concentrations.

Principles of Gas Flow Measurement Systems

1. New Ceramic Type

New ceramic sensors measure combustible gases using the heat generated upon combustion over an ultra-fine oxidation catalyst.

2. Semiconductor Type

Semiconductor sensors detect gases through changes in resistance when a metal oxide semiconductor interacts with the gas.

3. Hot Wire Semiconductor Type

Hot-wire semiconductor sensors detect flammable gases through changes in electrical conductivity resulting from gas adsorption and oxidation reactions on oxide semiconductor surfaces.

4. Heat Conduction Type

Heat conduction sensors differentiate gases based on their thermal conductivity by exposing them to a heated element.

5. Constant Potential Electrolysis Method

Constant potential electrolysis sensors measure gas by the current generated during electrolysis at a constant electrode potential.

6. Diaphragm Galvanic Cell Type

Diaphragm galvanic cell sensors detect oxygen concentrations by measuring the current generated during oxygen electrolysis on an electrode.

7. Infrared Type

Infrared sensors measure gas concentrations based on the absorption of infrared rays emitted from an internal light source by the gas.

How to Choose a Gas Flow Measurement System

When selecting a gas flow measurement system, consider the specific gas types, environmental conditions, and required sensitivity. Each sensor type offers unique advantages, such as response time, accuracy, and longevity, suited to different applications.

What Is Bronze Pipe?

Bronze pipe is a piping system with very good thermal conductivity and corrosion resistance.

Bronze pipe is also highly flexible and easy to install. Piping is divided into metallic and non-metallic tubes according to material. Metallic tubes include steel, stainless steel, and aluminum tubes, while non-metallic tubes include polyethylene, polybdenum, and polyvinyl chloride tubes.

They are often used in building equipment, heating and cooling systems, and industrial applications. There are two main types of bronze pipe: soft and hard. Soft bronze pipe is bendable and suitable for piping work, while hard bronze pipe is less bendable and used for construction applications and high-pressure piping. Bronze pipe is more expensive than steel pipe, but it is an environmentally friendly material with high recyclability.

Uses of Bronze Pipe

1. Buildings

Because of its light weight, corrosion resistance, and antibacterial properties, copper tubing is used in tight spaces such as the backs of buildings and in piping for hot water and drinking water. It is flexible and easy to process, and can be manufactured in complex shapes and connected with crimp fittings or brazing. 

2. Heat Exchanger

With high thermal conductivity, steel pipes are used in heat exchangers, solar thermal power generation, and other equipment that heats or cools. Steel tubes have high strength but low thermal conductivity, making them vulnerable to rapid temperature changes and possible deformation or breakage. Bronze pipe, however, is highly flexible and corrosion resistant, giving it a long service life.

3. Other

Bronze pipe is used in a wide variety of fields, including automotive motor parts due to its high electrical conductivity, CPU cooling systems for PCs and game consoles due to its high thermal conductivity, and medical gas piping due to its high corrosion resistance.

Features of Bronze Pipe

1. Antibacterial Properties

Copper tubing has been proven to inhibit the growth of Escherichia coli O-157 and Legionella bacteria, and to inactivate the infectivity of influenza and norovirus viruses. It was once believed that “green rust,” a type of copper rust, was a toxic substance, but this has now been verified to be harmless.

2. Corrosion Resistance

Corrosion is prevented by forming an oxide film bonded with oxygen on the surface, but acid, alkali, sulfur compounds, seawater, and sea breezes can corrode it. As with steel pipes, painting or corrosion inhibitors should be used. Chromic acid and benzotriazole are used as corrosion inhibitors, and resin-based epoxy resins are used for coating.

3. Thermal Conductivity

Because it conducts heat about 7 times more easily than iron and 20 times more easily than stainless steel, it is used in heating equipment, cooling equipment, mold cooling piping, refrigeration piping, and heat exchangers for air conditioning. Gold and silver are also effective in heat transfer, but they are very expensive and cannot maintain their strength, so copper is the most economically rational.

4. Workability

Soft bronze pipe can be easily bent, allowing for dense piping in tight spaces or to increase the contact area. However, small-diameter piping can be bent even by hand and may be bent or damaged by contact after installation.

5. Low-Temperature Resistance

Copper has superior low-temperature brittleness compared to iron. At low temperatures, iron tends to become brittle and is sensitive to sudden temperature changes. However, copper is relatively tough under such conditions and exhibits better wear and corrosion resistance than iron.

This is due to copper’s high thermal conductivity and low coefficient of thermal expansion, properties that are stable even at high temperatures.

6. Electrical Conductivity

When used with piping for wiring, the tube itself can be used as a grounding wire to prevent electrical leakage.

Types of Bronze Pipe

Copper tubes are classified by outer diameter, tube thickness, bending radius, and pressure resistance performance.

1.Oxygen-Free Bronze Pipe

Also called “O” material, this is a soft tube available in straight and coiled forms. It is widely used for wiring, refrigerant pipes, water pipes, etc.

2. Oxygenated Bronze Pipe

O-el material and its properties are similar to those of oxygen-free copper. Tough pitch copper is a typical example and is less expensive than oxygen-free copper. However, when heated above 600°C, hydrogen embrittlement occurs, which may cause cracking and splitting. 

3. Semi-Hard Bronze Pipe

It is mainly used in refrigerant straight pipes. Since it can be bent with a bender, it is used in places where pressure is applied and complex shapes are required, such as automotive pipes. 

4. Hard Bronze Pipe

Also called hard material, it is very hard and strong and cannot be bent. It is used in places where strength is required, such as construction piping, refrigeration piping, and hydraulic piping.

What Is a Metal Washer?

A metal washer is a component inserted between a bolt and a nut to evenly distribute pressure across the fastening area. This distribution ensures uniform contact between parts, resulting in a stronger fastening. Metal washers prevent deformation or breakage of parts due to uneven pressure and avoid direct metal-to-metal contact, reducing friction and corrosion.

Applications of Metal Washers

Metal washers are versatile components used in various industries, including construction, automotive, electronics, and industrial machinery. They enhance fastening stability, protect against wear, and in some cases, maintain electrical conductivity.

1. Construction Industry

Used to fasten materials in steel-framed buildings, concrete fixtures, and wood assemblies, metal washers handle large loads and ensure durability.

2. Automotive Industry

Essential for suspension systems and body assembly, metal washers provide stability and protect against vibrations and road shocks.

3. Electronic Equipment

Stabilize connections and ensure grounding in household appliances and computers.

4. Industrial Machinery

Strengthen connections and reduce part wear in machines exposed to high loads and harsh environments.

Principles of Metal Washers

Metal washers promote uniform contact between parts, enhancing the stability and reliability of connections. Made from materials like iron, stainless steel, brass, titanium, and aluminum, these components are designed for durability and long-term stability, adhering to standards like ISO, DIN, and JIS to meet specific application needs.

How to Choose a Metal Washer

Selecting the right metal washer involves considering the material, compliance with standards, nominal diameter, and type. Factors such as environmental exposure, rust resistance, and the specific requirements of the application (e.g., vibration damping or loosening prevention) dictate the choice of material, standard compliance, and washer type.

1. Material

Choose based on the environment of use, with options like iron, stainless steel, and brass for their respective properties and applications.

2. Compliant Standards

Select washers that adhere to international or domestic standards to ensure compatibility and performance.

3. Nominal Diameter

Ensure the washer fits the bolt or nut size, considering both inner and outer diameters for proper pairing.

4. Types

Consider the specific needs, such as vibration damping with spring washers or loosening prevention with lock washers, to select the appropriate type of washer.

What Is a Bearing Spacer?

A bearing spacer is a component used in conjunction with bearings to maintain the proper positioning and functionality of the bearings. Typically, bearings are used by inserting a shaft into their inner diameter and fixing the outer diameter to the housing, with the spacer playing a key role in this assembly.

Spacers are employed to fix the shaft in the axial direction. They are available in two types: one for the inner ring and another for the outer ring of the bearing. Each spacer type has a simple cylindrical shape and can be sourced either from the bearing manufacturer or another supplier.

Uses of Bearing Spacers

Bearing spacers are used alongside components like bearing holding pins to securely hold the width of the inner or outer ring of a bearing. Their primary function is not to hold the bearing in place alone but to assist in conjunction with other fixing components. For example, when using a ball bearing with a bearing retainer pin and a spacer, the spacer is aligned and tightened with the bearing and pin to ensure proper positioning and function.

Principle of Bearing Spacers

Bearing spacers have a straightforward cylindrical design. The inner diameter of the inner ring spacer matches the inner diameter of the bearing, while the outer diameter of the outer ring spacer aligns with the bearing’s outer diameter. This design allows the spacer to support the bearing without interfering with the shaft or housing.

These spacers are dimensionally tailored to the specific bearings they are used with and do not affect the lubrication within the bearing. In more demanding operating environments and conditions, bearing manufacturers may design custom spacers specifically for their bearings.

Using spacers enables the mounting of bearings without requiring special machining on the shaft or housing. This can be particularly useful in applications where bearings are mounted on flat plates with only tapped holes and holding pins, allowing for smooth bearing rotation while maintaining proper axial positioning.

What Is a Jumper Cable?

A jumper cable is a tool used to create short circuits between two points in electronic circuits and control panels. These cables are integral in printed circuit boards, control panels, and breadboards for experiments, allowing for quick and simple shorting or opening between points. They facilitate easy switching between multiple circuits.

Uses of Jumper Cables

Jumper cables are essential in various electrical circuit applications, including:

• Diagnosing electrical circuit failures.
• Evaluating operations of printed circuit boards and control panels.
• Conducting experiments on breadboards.
• Setting operations on printed circuit boards.

Primarily, they are used for temporary configuration changes in electrical circuits. However, incorrect use can lead to dangerous short circuits in power supply circuits. Therefore, careful examination of circuit diagrams and manuals is necessary before application.

Principle of Jumper Cables

Most jumper cables use vinyl-insulated wires made of copper and coated with vinyl. They can have either stranded or single-core wires, based on the application. The wire ends typically have a clip or terminal, such as minnow clips, round terminals, or breadboard sockets. The length of jumper cables usually does not exceed 1 meter, as they are often used for nearby short-circuiting tasks.

Types of Jumper Cables

Jumper cables vary in terminal types, with common examples including:

1. Male Pin Terminals

These have pins on the ends, suitable for insertion into breadboards or female sockets.

2. Female Pin Terminal

Designed to plug into male pin terminals, commonly used for microcontroller boards like Raspberry Pi.

3. Minomushi Clip Terminal

Feature metal clips on the ends, allowing easy connection and disconnection with various wire thicknesses.

Jumper cables can have “male,” “female,” or a combination of these ends. U-shaped jumper wires are used for equidistant connections on breadboards.

Other Information on Jumper Cables

1. Color of Jumper Cables

They often come in 2 or 4 cores, especially for use in telephone terminal boards. The color coding, while not standard, aids in maintenance and identification.

2. Setting Circuit Constants Using a Breadboard

Breadboards and jumper cables are used to determine optimal constants for electronic circuits. A breadboard allows for component insertion and circuit assembly for experimental purposes. By connecting jumper cables to different resistors, various circuit configurations can be tested and evaluated.

What Is Cresol?

Cresol, a methylphenol compound with the molecular formula C7H8O, is a colorless or yellowish liquid with a characteristic odor. It exists in three isomers: ortho, meta, and para. Derived from coal and wood tar, it’s insoluble in water but soluble in ethanol and diethyl ether.

Uses of Cresol

As a disinfectant and solvent, Cresol is utilized in various industries, including the production of fragrances, dyes, insecticides, synthetic resins, lubricating oils, and explosives. It’s also employed in the medical field as a disinfectant in various forms.

Medical Applications

Used for skin disinfection and sterilizing medical equipment, Cresol’s effectiveness varies with concentration. It’s used in lower concentrations for sensitive areas and must be handled carefully to avoid skin absorption and potential toxicity.

Sterilizing Effects

Cresol’s sterilizing power is stronger than phenol but weaker against spores and most viruses. Commercially available Cresol soap, once a common disinfectant, is now used mainly in specific scenarios like flood aftermaths and livestock epidemics.

Storage Recommendations

Cresol should be stored at room temperature in airtight, light-shielded containers. Over time, it may darken or slightly alter in appearance depending on the container material. Care is needed to prevent odor migration.

What Is Creosote Oil?

Creosote oil is an extracted oil obtained from petroleum and is a mixture of various organic compounds. It is obtained by distilling coal tar from petroleum at temperatures between 200°C and 400°C.

Creosote oil contains a wide variety of substances, including aromatic hydrocarbons such as toluene, polycyclic aromatic hydrocarbons such as naphthalene and anthracene, tar acids such as phenol, and tar bases such as pyridine. It is mainly used as a carbon source.

Creosote Oil is mainly used as carbon black to make rubber for tires and other applications, and as a wood preservative and waterproofing material.

Uses of Creosote Oil

Creosote Oil is mainly used as carbon black as a raw material for rubber such as tires, and as a reinforcing material for various other black resins such as black ink and copier toner.

It is also known as a wood preservative and waterproofing material because its application to wood surfaces prevents moisture from adsorbing to the wood. Uses for creosote oil-applied wood include underwater structures such as piers, railroad sleepers, and log houses.

Other uses of creosote oil include as a protectant to prevent stains from adhering to concrete piles in saltwater, as a lubricant for metal parts, as a repellent for birds and animals, and as an insecticide.

Properties of Creosote Oil

Creosote Oil is an organic compound with CAS No. 8001-58-9 and is a brownish liquid with a distinctive strong odor. It is a mixture of a wide variety of compounds, including aromatic hydrocarbons and tartaric acids, so its molecular weight is not specified.

Creosote Oil is insoluble in water and is well soluble in a variety of organic solvents, including diethyl ether and ethanol.

Other names for creosote oil include creosote, coal creosote, and industrial creosote.

Other Information on Creosote Oil

1. Toxicity of Creosote Oil

Creosote Oil is a skin and eye irritant; therefore, it is recommended that protective equipment covering the skin and eyes, such as protective gloves and safety glasses, be worn when using creosote oil.

Creosote Oil should be handled in a well ventilated area as it is a compound that has been linked to the risk of hereditary diseases and carcinogenesis. It should also be stored in a well ventilated area with the container sealed. 

2.Precautions for Use of Creosote Oil

Creosote Oil has a relatively high flash point of 66°C or higher, but once it ignites, it is difficult to extinguish due to its high combustion temperature.

It also has the property of burning while emitting irritating and corrosive toxic gases. Before using creosote oil, please make sure that there are no heat sources or spark-producing equipment around.

In the event of a fire caused by creosote oil, you should not spray water, but foam, powder fire extinguishers, carbon dioxide, dry sand, etc. must be used to extinguish the fire.

Creosote oil is a compound that must not be released into the environment. When disposing of creosote oil, please contact a professional waste disposal company.

3. Precautions for Transporting Creosote Oil

Specifically, creosote oil should not be mixed with food or feed, should not be exposed to direct sunlight, and should not be loaded on top of heavy objects.

What Is Coumarin?

Coumarin is an aromatic compound with a lactone (cyclic ester) structure. It is stable in a solid state at room temperature, but is soluble in alcohol, ether, chloroform, and volatile oils, so it is often used in a dissolved state. This compound is found in cherry leaves, cinnamon, and plants of the tangerine and legume families. Its characteristic feature is its aroma, and it is also a component of the sweet aroma of sakura mochi (cherry blossom cakes).

It also has antioxidant, antibacterial, and anti-blood coagulation effects, and is believed to be effective in preventing swelling and aging.

 

Distribution and Forms of Presence of Coumarin

Coumarin is abundantly contained in plants of the family Ceraceae, tangerine family, and leguminous family, and exists as a glycoside in plant organisms. Glycoside here refers to the presence of coumarin bound to sugars. Interestingly, coumarin as a glycoside does not have a specific aroma. The sweet aroma characteristic of sakura-mochi, as described above, is not due to the coumarin glycoside, but to the coumarin resulting from its hydrolysis.

Physicochemical Properties of Coumarin

1. Molecular Formula

C9H6O2

2. Molecular Weight

146.14

3. Structural Formula

As shown above. 

4. Melting Point

72°C

5. Solvent Solubility

Easily soluble in diethyl ether, chloroform, pyridine, soluble in ethanol

6. Fluorescence

Emits yellowish green fluorescence when irradiated with ultraviolet light.

Synthesis of Coumarin

It is synthesized from salicylaldehyde, acetic anhydride, and sodium acetate by the Parkin reaction.

Characteristics and Uses of Coumarin

1. Unique Aroma

Coumarin is one of the components of the so-called “cinnamon aroma,” from which the sweet aroma of sakura-mochi is derived. This aroma is also reported to have a relaxing effect. Because of these characteristics, it is used as an ingredient in air fresheners and perfumes.

2. Health Benefits

Coumarin is reported to improve blood flow and is thought to be effective in preventing swelling. In addition, its antioxidant properties help to remove active oxygen in the body. Because of these characteristics, coumarin is also expected to have an anti-aging function. On the other hand, it can cause liver damage if consumed in large quantities. Therefore, its use in the food industry is approved only as a component of flavorings and as a food additive for flavoring. 

3. Coumarin-Related Compounds as Pharmaceuticals

Some compounds with coumarin skeleton have blood coagulation inhibitory activity. A typical example is warfarin. This compound is a biologically active substance synthesized from dicoumarol, a metabolite of coumarin, as a lead compound, and is currently used as a blood coagulation inhibitor and rodenticide.

4. Fluorescence and Use as a Diesel Fuel Identifier

In some countries, coumarin is added to kerosene and fuel oil. The yellowish-green fluorescence of commercially available kerosene when irradiated with a black light is due to this coumarin as an additive, and is not a property of the kerosene itself. This use of coumarin is a good example of utilizing the two chemical properties of coumarin, its high fat-solubility and fluorescence.

What Is a Guide Pin?

A guide pin is a component used to align boards or workpieces with molds during the punching of printed circuit boards or the cutting of workpieces. It is typically attached to one side of the mold to secure the board or workpiece in place, ensuring precise alignment and preventing misalignment during processing.

The number, positions, materials, and shapes of guide pins can vary, allowing for customization based on specific molding or jig requirements.

Uses of Guide Pins

Guide pins play a crucial role in the trial cutting of printed circuit boards and in accurately aligning workpieces with jigs and processing machines. They are installed in configurations tailored to the specific needs of single-sided or double-sided/multilayer printed circuit boards, often diagonally, to ensure stability and precision during the cutting process.

Principles of Guide Pins

The primary function of guide pins is to ensure the correct alignment of molds or workpiece jigs with the boards or workpieces being processed. This is achieved through a pin-and-hole system, where the guide pin fits into a corresponding guide hole on the material, facilitating accurate alignment and insertion.

Types of Guide Pins

Choosing the right guide pin, considering the material and tip shape, is vital for performance and durability. Materials like iron, stainless steel, and aluminum are common, with hardening treatments to prevent wear. The tip shape, designed to minimize damage during setup, varies to suit different insertion and removal needs.

1. Classification by Material

Guide pins are made from materials that resist wear from repeated use, such as iron (SKS), stainless steel (SUS), and aluminum, often hardened to enhance durability.

2. Classification by Tip Shape

The tip design of guide pins, ranging from rounded to tapered or flat, is crucial for preventing damage to the workpiece during setup and varies based on the application’s specific requirements.

Other Information on Guide Pins

1. Difference between Guide Bush and Support Pin

Though similar in terminology, guide bushes and support pins serve distinct functions from guide pins. Guide bushes stabilize workpieces on lathes, while support pins are used for length adjustments in applications like scaffolding.

2. Environmental Measures with Grooved Guide Pins

To address environmental concerns, manufacturers have developed oil-free guide pins by incorporating solid lubricants into the design, reducing the need for lubricating oil.

3. Clearance between Guide Pin and Guide Hole

The clearance between guide pins and guide holes is critical for machining accuracy and requires adjustment based on the thickness of the printed circuit board to prevent damage or inaccuracies during removal or processing.