JPS6023697B2 - Friction material and clutch motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cork friction material used in an electromagnetic clutch/brake, and more particularly to a cork friction material that prevents friction over a long period of time and has a stable coefficient of friction, and a clutch motor using the same.

These friction materials are suitable for use in electromagnetic clutches that require high reliability.
Used for motors with brakes (hereinafter abbreviated as clutch motors).

A typical example is the drive motor of an industrial sewing machine that repeatedly starts and stops, and its output is 400.
It is used at a rotational speed of about 5000 ypm at about W. Therefore, the friction materials used in these products are designed to reduce the impact and squealing noises that occur when clutches and brakes operate.
It is desired that the friction material does not generate any strange odor and that it has a high coefficient of friction for miniaturization. 1 more per day
It is required to maintain a sufficiently long life even after repeated starting and stopping approximately 10,000 times. Cork is relatively soft among friction materials, so it has the advantage of being soft to the touch during operation, generating little odor, and having a relatively high coefficient of friction.

To this end, molded products are used as friction materials for clutch motors, such as those made by heating and compressing particles obtained by crushing natural wood cork together with a binder such as phenol resin, urea resin, or vinyl acetate resin. has been used exclusively.

However, such friction materials have a relatively large difference between the static friction coefficient and the effective friction coefficient, tend to cause adhesion and slippage, and cannot be said to have good wear resistance. Also, the coefficient of friction tends to change over time under high loads. This change in the coefficient of friction causes the torque transmitted through the clutch line to fluctuate, making starting and stopping control extremely difficult. An object of the present invention is to provide a friction material that takes advantage of the advantages of cork friction materials and has a constant torque transmission force, that is, a stable friction coefficient and wear resistance.

For the purpose of measuring wear resistance and stability of the coefficient of friction, methods are already known in which the surface of cork is coated with a composition consisting of graphite powder or molybdenum disulfide powder and a liquid or grease.

Although this method prevents squealing noise, stabilizes the coefficient of friction, and improves wear, the effects are small and the material is not necessarily sufficient as a desired friction material. In addition, as a further improved method, cork is impregnated with a liquid material having lubricating properties,
Furthermore, it is known to coat surfaces with the above compositions.

However, in this case, the coefficient of friction decreases and it becomes easy to slip, so there is a drawback that the rotational torque of the motor is not sufficiently transmitted to the driven side. The decrease in the coefficient of friction at this time is thought to be due to the fact that the oil impregnated into the cork causes the cork surface to become slippery too much.

Therefore, as a result of research from various angles on a cork friction material that is wear resistant over a long period of time, can sufficiently transmit the rotational torque of the motor, and has good braking performance, and its processing method, the present invention has been completed. did it.

The feature of the present invention is that the process of impregnating the cork friction material with a liquid material having lubricity to prevent squeaking noise and improve wear resistance, and coating the surface with a coating agent such as graphite or molybdenum monosulfide, The remaining part is that ferromagnetic powder is mixed into the cork molded product.

In other words, a certain proportion of ferromagnetic powder is mixed with cork particles,
After adding a binder to this, it is heated and compressed to produce a friction material. A liquid substance is soaked into this friction material, and a coating agent is further applied to the surface. When the cork friction material produced by this method is used in a clutch motor, sufficient rotational torque transmission and braking can be obtained even though it is impregnated with oil. This is thought to be due to the highly magnetic powder coexisting with the friction material, and when the field coil is energized during start/stop operations, magnetic force is generated in the friction material, increasing the attractive force. By the way, as a ferromagnetic powder,
An alloy consisting of one or more of iron, cobalt, and nickel is used. There is a proportional relationship between the amount of ferromagnetic powder mixed with cork particles and the attractive force, and it is desirable that the amount of ferromagnetic powder mixed is large. However, if the amount is too large, the mechanical strength of the cork molded product, such as tensile strength and trout breaking strength, will be reduced by 4.5%, so it is generally preferable to use 100 to 20 parts by weight per 100 parts by weight of cork. The amount to be added is determined depending on the purpose. The particle size of the cork particles used in the present invention is not particularly limited, but is generally preferably about 10 to 60 mesh.

In addition, ferromagnetic powder is not particularly limited, but iron, cobalt,
Alternatively, ferromagnetic powder such as nickel is particularly effective, and commercially available products can be used. Examples of hydrophobic and lubricating liquids include commercially available mineral oil, dihydrochloric acid ester oil, neobentyl polyol ester oil, fluoroester oil,
Those selected from silicate ester oil, phosphate ester oil, polyglycol oil, polyphenyl ether oil, aromatic C-ether oil, polyolefin oil, fluorosilicone oil, and silicone oil are used. The binder is not particularly limited as long as it is commonly used for molding cork, such as phenol resin, urea resin, vinyl acetate resin, etc.

As the coating agent, the above-mentioned liquid material or a composition prepared by mixing graphite powder, molybdenum sulfide powder, etc. with grease made by enriching the liquid material with metal soap, inorganic polymer, or inorganic powder is used.

Next, the present invention will be explained by way of examples.

In each of the following examples, parts refer to parts by weight. Example 1 24.8 parts of cork particles (20-60 mesh),
and 30 parts of iron powder were mixed for 3 minutes using a household mixer, then 6.2 parts of phenolic powder binder was added and mixed for 1 minute until uniform.

The above mixture was compressed and fixed under pressure at 160° C. for 3 minutes to produce a cork molded product containing ferromagnetic powder (1320 x 5 legs). Next, fluorosilicone oil 100 ratio st (
After immersing the cork molded product in this for 3 hours, apply the coating agent (2yo) to the surface of the cork molded product.
Fluorosilicone grease (tray FB3451 ((
A mixture of 1 graphite (13,000 mesh) and 2 anchors was applied to each of the 16 anchor sections. Using the above-mentioned ferromagnetic material-containing cork molded product as a friction material, the amount of wear of the cork transmitted to the driven side and the friction material was measured using the testing machine shown in FIG.

In FIG. 1, 1 is a 400W drive motor, 2 is a clutch disk, and 3 is a cork friction material inserted into a clutch ring 4. In addition, 5 is a field coil for attracting the clutch ring to the disk, and during measurement, the voltage and current flowing through this coil were determined to be 1.6k9. I made it so that 6 is a torque meter for measuring the torque transmitted through the friction material.

The measurement results are shown in FIGS. 2 and 3. Here, the friction material of Comparative Example 1 was prepared by adding 6.2 parts of a phenolic binder to 24.8 parts of cork particles (20 to instant mesh), mixing for 1 minute with a household mixer, and then adding 160 qo of the above mixture to 30
It is compressed and fixed for minutes. Comparative Example 2 uses a coating agent (fluorosilicone grease (tray FS3451) 16
A mixture of 0 parts and 2 parts of graphite (13,000 mesh) was applied to the surface of the cork of Comparative Example 1.

Comparative Example 3 uses fluorosilicone oil 100 ratio st (25°C
) was flooded with 100q C, and the cork of Comparative Example 1 was soaked in this for 3 hours, and then the coating agent used in Comparative Example 2 was applied to the surface of the cork.

The friction material of Example 1, which contains ferromagnetic powder, has an increased transmission torque compared to Comparative Example 3. Compared to Comparative Examples 1 and 2, the friction material of Example 1 has a stable transmission torque over time and is less prone to wear. The amount was also almost the same as Comparative Example 3. Example 2 24.8 parts of cork particles (20-60 mesh) and 61 parts of iron powder
2 parts were mixed for 3 minutes using a household mixer, and 8 parts of vinyl acetate-based emulsion adhesive was added as a solid content, and mixed for 1 minute until uniform.

The above mixture was compressed and fixed under pressure at 160 qo for 30 minutes to create a cork molded product containing ferromagnetic powder, 1320 x 5 sides. Jini Mineral Oil Extra Heavy 46 Ratio St (25
After soaking the above cork molded product in this for 3 hours, apply a coating agent (tin oil based grease (Sur Albania N03)) to 10 no Miyako graphite (1300 mesh). ) 20 parts mixed)
coated. As a result of measuring the transmitted torque force using the above cork containing ferromagnetic powder, as shown in Figure 2, the transmitted torque increased compared to Comparative Example 3, which was increased by Example 1, and the amount of wear was also decreased as shown in Figure 3. As shown, the amount was considerably less than Comparative Examples 1 and 2, and almost the same as Comparative Example 3.

As is clear from these examples, the cork friction material containing the ferromagnetic powder of the present invention increases the transmitted torque, so the surface of the friction material can have sufficient lubricity, and its life due to wear can be reduced. It is clear that it will be extended.

[Brief explanation of the drawing]

Figure 1 is a diagram of the transmission torque measuring device, Figure 2 is the change in transmission torque over time, and Figure 3 is when the clutch motor is turned on and off.
It is a graph showing the relationship between the number of times of operation and the amount of wear of the friction material. 1. ．．・...M motor 400W, 2...Clutch desk, 3...Friction material (cork), 4...
・Clutch ring, 5... Field coil, 6... Torque meter, 7... Inertial body (Booley). A'Faze Leopard 2 Figure 3

Claims (1)

[Claims] 1. In a cork friction material impregnated with a liquid having lubricating properties and coated with a liquid or grease composition of graphite or molybdenum disulfide on the surface, ferromagnetic powder is mixed into the cork. A friction material characterized by: 2. A clutch motor having a structure that includes a clutch ring provided with a cork friction material and a clutch disk disposed opposite to the clutch ring, and that transmits rotational torque of a motor connected to the clutch disk to the clutch ring side and performs braking,
The cork friction material has cork mixed with ferromagnetic powder and impregnated with a liquid material having lubricating properties, and the surface thereof is coated with a liquid or grease-like composition of graphite or molybdenum disulfide. Clutch motor featuring.