JP4204925B2 - Anti-friction coating for torque limiter and anti-friction coating for torque limiter - Google Patents

Description

In the present invention, the friction material is bonded to the base material (steel plate or resin) to form a friction surface with the counterpart material, and the friction is applied by directly applying the friction material to the base material surface instead of adhering the friction material. The present invention relates to a friction-resistant coating film for torque limiter that can form a surface, and a friction-resistant coating material for torque limiter for forming the friction-resistant coating film for torque limiter .

  For dampers and torque limiters used in automobiles, etc., the friction material bonded to the base material surface and the mating material (steel plate) come into contact with each other and the friction material slides at a constant torque, or the output shaft torque is suppressed, or The fluctuation of the output shaft torque is suppressed.

  In the “rotor torque limiter mechanism” of Patent Document 1, the friction material is formed of a sheet material made of a synthetic polymer material instead of a conventional felt material. This prevents torque fluctuations due to dimensional changes caused by the moisture absorption of the felt material, and the sheet material made of a synthetic polymer material is stiff and rigid. It is only necessary to arrange it between the body, and it is not necessary to adhere to either one, and the assembly process is shortened.

In addition, the “damper assembly with torque limiter” of Patent Document 2 has a configuration in which a molded friction material is incorporated. Despite the ever-increasing output of engines, the demand for smaller and space-saving devices is increasing, and it is inevitable that excessive torque is sometimes applied to the damper, leading to damage. The fear is growing. In order to solve this problem, a friction type torque limiter is provided between the input shaft or the output shaft and the hermetic damper.
JP-A-7-127656 JP 2002-181085 A

  However, both the technology described in Patent Document 1 and the technology described in Patent Document 2 use a molded friction material, which takes the cost of the mold and the time and effort of molding, It becomes expensive. Further, the conventional friction material has a problem in that rust is generated between the steel plate and the friction material, and problems such as clutch fixation occur.

Therefore, the present invention can reduce the cost by forming a friction surface by directly coating the base steel plate or resin instead of the formed friction material. It is an object of the present invention to provide a friction-resistant coating film for a torque limiter and a friction-resistant coating material for a torque limiter that can prevent problems such as clutch sticking and the like.

Rub paint torque limiter according to a first aspect of the invention, zinc dust, thermosetting resin, curing agent, dispersing agent, solvent, an abrasion paint for torque limiter consisting of water, constituting the torque limiter The amount of zinc in the coating film (solid content) formed by applying the anti-friction paint is applied to any contact surface of the friction material and the steel material at a portion where the friction material and the steel material contact each other. It is in the range of 60% to 75% by weight.

The friction-resistant paint for torque limiter according to the invention of claim 2 is the structure of claim 1, wherein the average particle size of the zinc powder is in the range of 1 to 20 μm.

Torque limiter for antifriction coating according to the invention of claim 3 is formed by applying a rub paint torque limiter according to any one of the contact surfaces of the steel and the friction member to claim 1 or claim 2 Is.

The friction-resistant coating film for torque limiter according to the invention of claim 4 is the structure of claim 3, wherein the amount of zinc in the coating film (solid content) is in the range of 60 wt% to 75 wt%.

The friction-resistant coating film for a torque limiter according to the invention of claim 5 is the structure of claim 3 or claim 4, wherein the thickness of the coating film is in the range of 15 μm to 35 μm.

Rub paint torque limiter according to a first aspect of the invention, zinc dust, thermosetting resin, curing agent, dispersing agent, solvent, an abrasion paint for torque limiter consisting of water, constituting the torque limiter It is applied to the contact surface between the friction material and the steel material at the portion where the friction material and the steel material are in contact with each other, and the zinc content in the coating film (solid content) formed by applying the anti-friction paint is from 60% by weight to It is in the range of 75% by weight.

In the friction-resistant paint for a torque limiter according to the invention of claim 1, the friction-resistant coating is applied to any contact surface of the friction material and the steel material at a portion where the friction material constituting the torque limiter and the steel material are in contact with each other. Since a coating film is formed, instead of adhering the friction material to the base material, by applying a friction-resistant paint to the base material surface, when the friction surface of the counterpart material is rubbed, the zinc cutting resistance becomes a frictional force. Appropriate coefficient of friction is obtained. It is also conceivable to add glass fiber or metal powder to the resin so that it has a function as a friction material. However, there is a drawback that the initial friction coefficient is not stable because the friction coefficient decreases in the resin layer portion on the surface. It was. On the other hand, in the coating film formed by applying the friction-resistant paint of the present invention, since the zinc is exposed from the beginning, a stable friction coefficient can be obtained from the initial stage of friction. Furthermore, since the friction-resistant coating film containing zinc is formed on the steel plate, rust is not generated by the sacrificial corrosion action of zinc, and clutch sticking in a flywheel clutch or the like can be prevented.

  Moreover, even if the zinc powder is hardened uniformly and firmly with a thermosetting resin as a binder, the zinc powder does not peel even if the coating film rubs against the counterpart material. Furthermore, when the amount of zinc in the coating film (solid content) formed by applying the anti-friction paint is less than 60% by weight, the fluctuation range of the friction coefficient becomes large and a problem arises in the adhesion, resulting in surface peeling. Begins to occur. On the other hand, when the amount of zinc exceeds 75% by weight, the coating film hardness is insufficient and the amount of the binder is insufficient, which also causes a problem in adhesion (applicability). Therefore, it is preferable that the amount of zinc in the coating film formed by applying the antifriction coating is in the range of 60 wt% to 75 wt%.

In this way, it is possible to reduce the cost by forming a friction surface by directly coating the base material steel plate or resin instead of the formed friction material. It becomes a friction-resistant paint for torque limiters that can prevent problems such as clutch sticking without occurrence.

In the friction-resistant paint for torque limiter according to the invention of claim 2, the average particle size of the zinc powder is in the range of 1 μm to 20 μm.

  If the average particle size of the zinc powder is within this range, an appropriate friction coefficient can be obtained when the frictional coating film containing a large amount of zinc powder rubs against the friction surface of the mating material and the cutting force of the zinc acts as a frictional force. It is done. If the average particle size of the zinc powder is smaller than 1 μm, frictional force due to cutting resistance cannot be obtained, and if the average particle size of the zinc powder is larger than 20 μm, the zinc powder cannot be firmly solidified with a binder, and the friction-resistant coating film is a counterpart material. Zinc powder may peel off when rubbed. Therefore, the average particle size of the zinc powder is preferably in the range of 1 μm to 20 μm.

In this way, instead of the formed friction material, the base steel plate or resin is directly coated with zinc powder having an appropriate average particle diameter, thereby forming a friction surface and obtaining an appropriate coefficient of friction. This is a friction-resistant paint for torque limiters .

A friction-resistant coating film for a torque limiter according to a third aspect of the invention is formed by applying the friction-resistant coating material for a torque limiter according to the first or second aspect to any contact surface of a friction material and a steel material.

Thus, in the friction-resistant coating film for torque limiter according to the present invention, the friction-resistant coating is applied to any contact surface of the friction material and the steel material at the portion where the friction material constituting the torque limiter and the steel material are in contact with each other. Therefore, when rubbing against the friction surface of the counterpart material, the cutting resistance of zinc becomes a frictional force and an appropriate friction coefficient is obtained. It is also conceivable to add glass fiber or metal powder to the resin so that it has a function as a friction material. However, there is a drawback that the initial friction coefficient is not stable because the friction coefficient decreases in the resin layer portion on the surface. It was. On the other hand, in the friction-resistant coating film of the present invention, a stable friction coefficient can be obtained from the initial stage of friction because zinc is exposed on the surface from the beginning. Furthermore, since the friction-resistant coating film containing zinc is formed on the steel plate, rust is not generated by the sacrificial corrosion action of zinc, and clutch sticking in a flywheel clutch or the like can be prevented.

  Moreover, even if the zinc powder is hardened uniformly and firmly with a thermosetting resin as a binder, the zinc powder does not peel even if the coating film rubs against the counterpart material.

In this way, it is possible to reduce the cost by forming a friction surface by directly coating the base material steel plate or resin instead of the formed friction material. It becomes a friction-resistant coating film for a torque limiter that can prevent defects such as clutch sticking without occurrence.

In the friction-resistant coating film for torque limiter according to the invention of claim 4, the amount of zinc in the coating film (solid content) is in the range of 60 wt% to 75 wt%. When the amount of zinc is less than 60% by weight, the fluctuation range of the friction coefficient becomes large, and a problem arises in adhesion, and surface peeling begins to occur. On the other hand, when the amount of zinc exceeds 75% by weight, the coating film hardness is insufficient and the amount of the binder is insufficient, which also causes a problem in adhesion (applicability). Therefore, the amount of zinc in the anti-friction coating is preferably in the range of 60% to 75% by weight.

Thus, instead of the molded friction material, to coat directly suitable amount of zinc powder steel or resin as the base material, resistant torque limiter suitable friction coefficient to form a friction surface is obtained It becomes a friction coating.

The friction-resistant coating film for torque limiter according to the invention of claim 5 has a coating film thickness in the range of 15 μm to 35 μm. If the thickness of the friction-resistant coating film is less than 15 μm, it is too thin to function as a friction surface, and if the thickness of the friction-resistant coating film exceeds 35 μm, the fluctuation range of the friction coefficient increases, which is not preferable. Therefore, the thickness of the friction-resistant coating film is preferably in the range of 15 μm to 35 μm.

Thus, instead of the molded friction material, by coating the zinc powder directly suitable thickness of the steel sheet or a resin as the base material, suitable friction coefficient to form a friction surface can be obtained torque It becomes a friction-resistant coating film for limiters .

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3.

  FIG. 1A is a perspective view showing a part in which a conventional friction material is pasted on a base material, and FIG. 1B is a perspective view showing a part coated with zinc as a friction-resistant coating film according to an embodiment of the present invention. Both are schematic diagrams in which the thickness of the friction material / coating material is exaggerated to be thicker than the actual thickness. FIG. 2 is a schematic diagram showing a method for measuring a friction coefficient of a zinc-coated component as a friction-resistant coating film according to an embodiment of the present invention. FIG. 3 is a diagram showing the change over time in the coefficient of friction of a zinc-coated part as a friction-resistant coating film according to an embodiment of the present invention compared with a part in which a conventional friction material is attached to a base material.

  As shown in FIG. 1 (a), a conventional friction component 1 has an adhesive (such as a thermosetting epoxy-based adhesive) bonded to a friction material 2 in which brass powder is mixed with a base resin 3 as a base material. 4, the cost of the molding die for molding the friction material 2 and the labor of applying and bonding the adhesive 4 and heating and curing it are high. On the other hand, as shown in FIG. 1B, the zinc-coated component 5 of the present embodiment is heat-cured by applying the friction-resistant paint of the present embodiment to the base resin 3 that is also the base material. In this case, the surface is formed with a zinc coating 6 as a friction-resistant coating, so that it does not take time, and therefore, the cost can be reduced compared with the conventional friction component 1. Note that PAGF (polyamide (nylon) glass fiber) reinforced resin was used as the base resin 3 of the present embodiment.

  Next, a method for producing a friction-resistant coating material according to this embodiment for forming the zinc coating film 6 as the friction-resistant coating film according to this embodiment will be described with reference to (Table 1).

  As shown in Table 1, the friction-resistant paint of the present embodiment has a water-based alkyd resin as the thermosetting resin of 64.4% by weight, a methyl etherified melamine as the curing agent of 6.5% by weight, and a dispersant. Mix 2.1% by weight of acetylenic diol-based dispersant, 14.0% by weight of butyl cellosolve as a solvent, and 13.0% by weight of ion-exchanged water. A suitable amount of zinc powder having an average particle size of 5 μm is added to this coating liquid and stirred so that the zinc content falls within the range of about 60 wt% to about 75 wt% when dried to produce a friction resistant coating. In the present embodiment, zinc powder was added to the coating liquid and stirred so that the zinc content would be several types, mainly about 70% by weight when dried.

  About this zinc coating film 6, about the relationship between the amount of zinc (Zn) and coating film performance, the measurement result was put together in the following (Table 2) compared with the comparative example. As a method for producing the zinc coating film 6, the friction-resistant paint of the present embodiment produced as described above is applied to an article to be coated by an air spray method, set at room temperature for 5 minutes, and then a dryer at 130 ° C. And baked for 20 minutes.

  As shown in Table 2, with respect to the zinc coating film 6, Comparative Example 1 in which the amount of zinc (Zn) contained was 80%, and Examples 1, 2, 3, 4, and 5% reduced from 75% to 60%. The coating film performance was measured for Comparative Example 2 with a zinc content of 50% and Comparative Example 3 with 30%. In addition, the friction coefficient of the conventional friction material 2 was also measured for comparison.

  As shown in Table 2, in terms of appearance, Examples 1 to 4 and Comparative Example 1 were good in ordinary zinc color, but Comparative Example 2 was brown, and Comparative Example 3 was brown. Regarding adhesion, Examples 1 to 4 and Comparative Example 2 had good surface peeling of 0%, Comparative Example 3 had 30% surface peeling, and Comparative Example 1 had only 0% surface peeling. However, since the ratio of the binder was small, peeling occurred on the surface layer, which was an undesirable result.

  Next, the coating film hardness was measured according to the “pencil hardness” measuring method of JIS (Japanese Industrial Standard). As a result, Comparative Example 1 was slightly soft as 2H, Examples 1 to 4 were good at 4H, Comparative Example 2 was 5H, Comparative Example 3 was 6H, and the coating hardness increased as the amount of zinc contained decreased. .

Finally, the friction coefficient was calculated by using a Suzuki friction and wear tester, pressing the steel plate with a constant pressure while rotating the specimen at a constant rotation speed, and measuring the sliding torque with a load cell. FIG. 2 shows a schematic diagram of a specific measurement method using a Suzuki friction and wear tester. As shown in FIG. 2, the steel plate 7 is pressed against the friction surface of the specimen (friction part) 5 having a radius r = 1.15 cm with a pressurized load W, and R = 10 cm away from the center of the specimen 5. From the load F detected by the load cell 8, a calculation formula (1) of the friction coefficient μ,
μ = (F × R) / (W × r) (1)
To calculate the friction coefficient μ. In this embodiment, since R = 10 cm and r = 1.15 cm, the expression (1) becomes the following expression (2).
μ = (F × 10) / (W × 1.15) (2)
As measurement conditions, the ambient temperature was room temperature, the pressure load W was 0.76 MPa / cm ² , and the sliding speed was 18 m / min.

  As a result, each of Examples 1 to 4, Comparative Example 1 and Comparative Example 4 had an initial friction coefficient of ≈0.4, and a fluctuation range (difference between the maximum value and the minimum value after 12 hours of friction) was 27% or less. However, Comparative Example 2 and Comparative Example 3 have high initial friction coefficients of 0.45 and 0.48, and a large fluctuation range of 28% or more.

  From the above results, the zinc content of the zinc coating film 6 is determined to be an optimum amount in the range of about 60 wt% to about 75 wt%.

  Next, the relationship between the film thickness of the zinc coating film and the friction coefficient will be described with reference to (Table 3).

  This test was performed using a friction-resistant paint having a zinc content of about 70% by weight. As a result, there were no problems in the appearance, adhesion, and hardness of the four types of anti-friction coating films, and the fluctuation range of the friction coefficient was as large as 38% when the film thickness was 100 μm. For other specimens with film thicknesses of 15, 25, and 35 μm, it was found that the initial friction coefficient and the fluctuation range were satisfactory, and the film thickness of the zinc coating film was preferably within the range of about 15 μm to about 35 μm. If the film thickness is smaller than about 15 μm, it is too thin to function as a friction surface, and if the film thickness is larger than about 35 μm, the fluctuation range of the friction coefficient becomes large, which is not preferable.

  Next, the conventional product 1 in which the friction material 2 is bonded to the PAGF reinforced resin 3 as a base material with the adhesive 4 and the friction resistant paint of the present embodiment are applied to the PAGF reinforced resin 3 to form a friction resistant coating film. Change with time of friction coefficient μ with friction component 5 on which a zinc coating film 6 (zinc content 70% by weight, zinc powder average particle diameter of about 5 μm, film thickness 25 μm) was formed is described with reference to (Table 4) To do. For comparison, the PAGF reinforced resin 3 itself was also measured as a friction surface.

  As a result, as shown in Table 4, the friction coefficient 5 (zinc coating) on which the conventional product 1 (friction material pasting) and the zinc coating 6 of the present embodiment are formed has an appropriate initial friction coefficient. The fluctuation range of the coefficient of friction after the 18.8 hour friction test is also small, 27% and 22%, respectively. In particular, the friction component 5 on which the zinc coating film 6 of the present embodiment is formed exhibits characteristics equal to or higher than those of the conventional product 1.

  On the other hand, when the PAGF reinforced resin 3 itself is used as a friction surface, the initial friction coefficient is small and the fluctuation of the friction coefficient is large. This is because only the PA (polyamide) resin is present on the surface layer of the PAGF reinforced resin 3 and no reinforcing GF (glass fiber) is present. The friction coefficient is considered to increase rapidly when the glass fiber appears on the surface. Therefore, the fluctuation range of the friction coefficient is as extremely large as 121%.

  FIG. 3 is a graph showing the measurement results in Table 4. As shown in FIG. 3, the zinc-coated product of the present embodiment has an extremely stable initial (0 to 2 hours) friction coefficient, and is superior to the conventional product (friction material-attached product). Therefore, it is expected that a friction part that only rubs for a short time such as a torque limiter will exhibit particularly excellent performance.

  As described above, the friction-resistant coating film obtained by applying the friction-resistant paint of the present embodiment to the base material and heat-curing contains a large amount of zinc, and since zinc is exposed on the surface from the beginning, it is stable from the beginning of friction. The coefficient of friction obtained is obtained. Furthermore, since a friction-resistant coating film containing a large amount of zinc is formed on the steel sheet, rust is not generated by the sacrificial corrosion action of zinc, and clutch sticking in a flywheel clutch or the like can be prevented. In this way, it is possible to reduce the cost by forming a friction surface by directly coating the base material steel plate or resin instead of the formed friction material. There is no occurrence and problems such as clutch fixation can be prevented. In addition, since the anti-friction coating is composed of zinc powder, thermosetting resin, curing agent, dispersant, solvent, and water, a large amount of zinc powder is uniformly and firmly hardened with the thermosetting resin as a binder. Even if the film rubs against the mating material, the zinc powder does not peel off.

  Moreover, since the average particle diameter of zinc powder is about 5 micrometers, when rubbing with the friction surface of a counterpart material, the cutting resistance of zinc becomes a frictional force and an appropriate friction coefficient is obtained. Furthermore, since the amount of zinc in the friction-resistant coating film (solid content) is about 70% by weight, the fluctuation range of the friction coefficient is small, and there is no problem in adhesion. And since the thickness of a friction-resistant coating film is about 25 micrometers, it functions as a friction surface enough and the fluctuation range of a friction coefficient is also suppressed small.

  In the present embodiment, the average particle size of the zinc powder of the friction-resistant coating film is about 5 μm, but it may be in the range of about 1 μm to about 20 μm. Further, although the zinc amount is about 70% by weight, it may be in the range of about 60% to about 75% by weight. Furthermore, although the thickness of the friction-resistant coating film is about 25 μm, it may be in the range of about 15 μm to about 35 μm.

  In this embodiment, the alkyd resin is used as the thermosetting resin of the friction-resistant paint, but other thermosetting resins such as an organic binder such as an epoxy resin and an inorganic binder such as an alkyl silicate are used. You can also.

In practicing the present invention, configuration of the other parts of the anti-friction coating or friction resistance paint torque limiter for torque limiter, shape, quantity, material, size, for the connection relationship, etc., limited to the embodiment Is not to be done.

FIG. 1A is a perspective view showing a part in which a conventional friction material is pasted on a base material, and FIG. 1B is a perspective view showing a part coated with zinc as a friction-resistant coating film according to an embodiment of the present invention. Both are schematic diagrams in which the thickness of the friction material / coating material is exaggerated to be thicker than the actual thickness. FIG. 2 is a schematic diagram showing a method for measuring a friction coefficient of a zinc-coated component as a friction-resistant coating film according to an embodiment of the present invention. FIG. 3 is a diagram showing the change over time in the coefficient of friction of a zinc-coated part as a friction-resistant coating film according to an embodiment of the present invention compared with a part in which a conventional friction material is attached to a base material.

Explanation of symbols

2 Friction material 3 Base material 4 Adhesive 5 Zinc coating part 6 Zinc coating

Claims (5)

A friction-resistant paint for torque limiters consisting of zinc powder, thermosetting resin, curing agent, dispersant, solvent, water,
The friction limiter constituting the torque limiter is applied to any contact surface of the friction material and the steel material at a portion where the friction material and the steel material are in contact with each other,
A friction-resistant paint for torque limiters, wherein the amount of zinc in the coating film (solid content) formed by applying the friction-resistant paint is in the range of 60 wt% to 75 wt%. The friction resistant paint for a torque limiter according to claim 1, wherein an average particle size of the zinc powder is in a range of 1 µm to 20 µm. A friction-resistant paint film for torque limiters , comprising the friction-resistant paint for torque limiters according to claim 1 or 2 applied to any contact surface of the friction material and the steel material. The friction-resistant coating film for a torque limiter according to claim 3, wherein the amount of zinc in the coating film (solid content) is in the range of 60 wt% to 75 wt%. The friction-resistant coating film for a torque limiter according to claim 3 or 4, wherein the thickness of the coating film is in the range of 15 µm to 35 µm.

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