JP3847522B2 - Coated bearing manufacturing method and apparatus - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for manufacturing a coated bearing. More specifically, the present invention relates to a solid lubricant such as molybdenum disulfide (MoS ₂ ), graphite or the like (hereinafter collectively referred to as “coating material” or “ It is related with the manufacturing method and apparatus of the coating bearing formed into a film with the back metal. Such coated bearings usually use the anchoring effect of sintered alloys such as bronze, lead bronze, phosphor bronze, etc. on the surface of a low carbon steel plate that may be subjected to surface treatment such as sanding, Alternatively, the surface is roughened by shot blasting, and the coating material is adhered. Further, it is possible to make the back metal surface by omitting the formation of a sintered alloy layer or the like to make it porous. Coated bearings generally used for engine bearings have a width of about 10 to 50 mm and a radius of about 30 to 200 mm. The sintered alloy layer generally has a thickness of 0.5 to 2 μm, and there are a bearing in which the sintered layer is completely covered with a coating material and a bearing in which a part is exposed. In the former case, the thickness of the coating material is generally 2 to 10 μm. As a coated bearing, there is one in which an inner surface of an engine bearing made of an aluminum alloy, kelmet or the like is used as a bearing alloy, and the overlay can be formed by a coating liquid.
[0002]
[Prior art]
According to US Pat. No. 5,178,814 (inventor: Kawakami et al.) Relating to a coated bearing, a back metal having a sintered bronze surface layer is dipped in a solid lubricant particle-dispersed resin liquid, and the solid lubricant is placed in the sintered pores. It is impregnated or this dispersion is applied to the surface layer of the sintered bronze. In general, a method of spraying the dispersion liquid on a semicircular arc backing metal is performed.
[0003]
In the general roll coating method, where paint is applied to aluminum alloy strips, etc., the paint accumulated in the coater pan is transferred to the strip surface sequentially through the pick-up roll, metering roll, and application roll, and the strip is rotated in the opposite direction. The coating is applied to the entire surface of the strip sandwiched between the metering roll and the backing roll (Japanese Patent No. 2851134). In the manufacturing process of coated bearings, the formation of the sintered alloy layer on the back metal is performed while the back metal strip is continuously threaded, but the coating material is not applied during the threading process, but is cut and pressed by a semicircular arc. It goes against the shape back metal. This is to avoid the film of the coating layer being peeled off by bending, the film thickness becoming non-uniform, or the surface roughness of the film changing.
[0004]
The required or desirable points for the coated bearing manufacturing method are as follows.
(1) The coating layer is lost where the coating material is thin or where the surface roughness is rough, and the sintered layer and the mating shaft come into contact with each other, causing deterioration of the sliding characteristics. The surface roughness must be uniform.
(2) In mass production, the film thickness and surface roughness of the coating material and the composition of the coating layer must be constant.
(3) Since the work environment deteriorates due to resin solvent evaporation and powder scattering, it is necessary to maintain a good work environment.
(4) In particular, powder scattering causes deterioration of coating performance, so it is necessary that the yield of the coating material be high.
(5) The coating material filling rate into the sintered pores is high. In general, it is necessary that the coating material, at least the resin, is sufficiently impregnated with a porosity of 5% or less, and the adhesive strength of the coating layer is high.
(6) Productivity must be high.
(7) It is desirable to avoid surface finishing after coating because it increases costs.
[0005]
[Problems to be solved by the invention]
The conventional coating method in the manufacture of coated bearings is not a method for continuously processing strips, and therefore has low productivity. However, when batch processing is performed in which a large number of arc-shaped backing plates are immersed in a paint pan or the like, productivity increases, but it is difficult to ensure a certain quality in mass production.
Regarding the conventional coating method, first, the spray method has problems in terms of yield and working environment. In addition, the amount of film formation at one time is about 1 μm, and usually requires many times of application, and the productivity is low. Next, the dipping method requires a long time to obtain a sufficient film thickness, is inferior in productivity, and in order to obtain a constant coating composition in mass production, the concentration of the solid lubricant in the coating liquid pan is constant. Need to manage. Finally, coating methods using brushes, slits, and pad printing are rarely used industrially due to many problems in terms of application to arc-shaped backing plates.
An object of the present invention is to provide a roll coating method and apparatus that can be applied to an arc-shaped backing metal of a coated bearing from the above viewpoint.
[0006]
[Means for Solving the Problems]
The method for producing a coated bearing according to the present invention is the method for producing a coated bearing in which a coating layer consisting essentially of a solid lubricant and a resin is formed on a semicircular arc-shaped body having an inner surface side as a sliding portion, and fired. At least one of the coating layers formed in the film-forming stage drops the coating liquid containing the solid lubricant and the resin onto the transfer roll, and makes the transfer roll and the printing roll contact with each other. The transfer roll and the back surface feeding means of the semicircular arc member are brought into rotational contact with each other, and the semicircular arc member is formed in the gap so that the inner surface thereof is in contact with the transfer roll. The coating bearing manufacturing apparatus according to the present invention includes a dispenser for dropping the coating liquid, a transfer roll disposed below the dispenser, and the transfer roll. A printing roll and a backup roll, and means for driving at least one roll to adjust the surface interval between the rolls. By this driving means, the roll surface of the printing roll and the backup roll are in contact with each other intermittently. The printing roll and the backup roll are opposed to each other with a gap allowing the semicircular arc member to pass therethrough. In the method of the present invention, in the case of multiple coatings, at least one layer is formed by this method, and each coating is preferably performed by this method. The present invention will be described in detail below.
[0007]
In the present invention, a thermosetting resin such as polyimide amide or polyimide, a solid lubricant and a small amount of a surfactant, and if necessary, hard particles such as iron phosphide are mixed to have a viscosity of 500 to 4000 cps, preferably 1000 to 2000 cps. Let the liquid be. Such a coating liquid is, for example, 70% MoS ₂ and the remainder polyamideimide resin. As shown in FIG. 1, when droplets are dropped from the dispenser 1 onto the transfer roll 3 at 25 to 30 ° C., scattering that cannot be avoided by the spray method can be eliminated, and a coating pan or the like is used. Changes in the component concentration that occur when doing so can be avoided. In the method using the continuous flow, the amount of the coating liquid that flows down from the transfer roll is increased and waste is increased. However, this method can avoid this problem. Although the dropping of the coating liquid is sufficient from only one place, it may be performed from two or more places if necessary. The coating liquid 4 adheres to the transfer roll 3 with sufficient adhesion due to the viscosity of the resin. However, if the surface of the roll surface such as an etching roll or a shot blast roll is uneven, a more desirable amount of coating liquid may be adhered. it can.
[0008]
Next, as shown in FIG. 2, the coating roll 4 and the printing roll 5 arranged in parallel with the transfer roll 3 are brought into contact with each other and rotated to uniformly spread the coating liquid 4 on the entire surface of the printing roll 5. The cumulative number of contact rotations of either or both rolls is determined so as to uniformly spread the coating liquid.
[0009]
Next, after uniformly spreading the coating liquid, a coating material is applied to the inner surface of a semicircular arc shaped body (hereinafter referred to as “back metal”) 6 preheated to 40 to 70 ° C. if necessary. For this purpose, it is necessary to provide a back feeding means for applying a coating liquid by applying a force for the backing metal 6 to rotate around the printing roll 5. For this, a conveyor, one or more rolls can be used, but in the following description, an example of the backup roll 7 (FIG. 3) will be described.
As shown in FIG. 3, when the printing roll 5 and the backup roll 7 are brought close to each other and the gap is brought close enough to move downward while the back metal 6 is bitten, the printing roll 5 applies the coating liquid to the inner surface of the back metal 6. Apply and feed the backing metal 6 downward along its circular arc trajectory. The peripheral speed (V ₁ ) of the printing roll 5 is preferably faster than the peripheral speed (V ₂ ) of the backup roll 7 and more preferably V ₁ ≦ 1.3V ₂ . The backup roll 7 is preferably provided with a groove in the circumferential direction for positioning the back metal 6. The transfer roll 3, the printing roll 5, and the backup roll 7 may be widened to coat two or more back metal 6 in parallel.
Drying is performed after applying the coating liquid, and the above steps are repeated as necessary. For example, in order to form a coating layer having a thickness of 6 μm, it is necessary to repeat about three times. Thereafter, when a polyimide resin is used, baking is performed at about 250 to 300 ° C.
[0010]
Next, an embodiment of the coating apparatus according to the present invention will be described with reference to FIG.
The transfer roll 3 and the printing roll 5 can be moved in the horizontal direction by a roll displacing means 10 formed of a cylinder or the like, and the above-described application of the coating liquid and application to the back metal 6 are performed at the following timing. The pressurized gas source 11 always sends pressurized gas to the dispenser 1 to drop, for example, several g of droplet 2, but the roll displacement command means 12 commands the pressurized gas source 11 to stop supply, and then the roll The displacing means 10 is energized to move the transfer roll 3 from the dotted line position to the solid line position to transfer the coating liquid to the printing roll 5. Receiving a signal from the sensor 13 for detecting the contact of the rolls 3 and 5, the rotation number counter 14 adds up the accumulated rotation number of the printing roll 5, and when a predetermined number, for example, five rotations is obtained, the accumulated rotation number storage means. A command is issued from 15 to the roll displacement means 10 via the roll displacement command means 12, and the printing roll 5 is brought close to the backup roll 7. When the sensor 13 detects that the rolls 5 and 7 approach each other at a predetermined interval, the back metal 6 falls from the feeder 17 into the gap between the rolls 5 and 7 when a signal for depressing the stopper 15 is given from the stopper urging means 16. Then the coating liquid is applied. Thereafter, a signal for urging the stopper 15 is given from the stopper urging means 16 to stop the fall of the back plate 6. After the stop signal is generated, (i) the transfer roll 3 is returned to the original position, and (b) the printing roll 5 To the original position, (c) the rotational speed accumulation storage means 15 is reset to the initial value (zero), and (f) the start of gas pressurization is sequentially performed. The series of steps described above can be performed by sequence control or microcomputer control.
[0011]
【The invention's effect】
As described above, according to the present invention, a manufacturing method and apparatus satisfying the requirements described in paragraph 0004 are provided.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram of a transfer roll.
FIG. 2 is a conceptual diagram of a transfer roll and a printing roll during coating liquid transfer.
FIG. 3 is a conceptual diagram of a printing roll and a backup roll during application of a coating liquid.
FIG. 4 is an explanatory diagram of a coating apparatus.
[Explanation of symbols]
1-dispenser 2-droplet 3-transfer roll 4-coating liquid 5-printing roll 7-backup roll

Claims (7)

In a manufacturing method of a coating bearing, in which a coating layer substantially consisting of a solid lubricant and a resin is formed on a semicircular arc-shaped body whose inner surface side is a sliding portion, and fired, the coating layer formed in the film forming step At least one layer drops the coating liquid containing the solid lubricant and the resin onto the transfer roll, makes the transfer roll and the printing roll contact with each other, and subsequently feeds the back surface of the transfer roll and the semicircular arc member. A method for manufacturing a coated bearing, characterized in that the means is rotated and the semicircular arc-shaped body is inserted into the gaps so that the inner surface thereof is in contact with the transfer roll. 2. The method of manufacturing a coated bearing according to claim 1, wherein the transfer roll and the printing roll are brought into rotational contact with each other a plurality of times. The method for manufacturing a coated bearing according to claim 1, wherein dripping of the coating liquid is stopped while the transfer roll and the printing roll are in contact with each other. The method for manufacturing a coated bearing according to any one of claims 1 to 3, wherein the back surface feeding means is a backup roll. 5. The method of manufacturing a coated bearing according to claim 4, wherein the peripheral speed of the printing roll biting the semicircular arc backing metal is increased by 30% at a maximum from the peripheral speed of the backup roll. A dispenser for dropping the coating liquid, a transfer roll disposed below the printing roll, a printing roll and a backup roll arranged in parallel with the transfer roll, and at least one roll is driven to adjust the surface spacing of these rolls. The printing roll and the backup roll are intermittently brought into contact with each other by the driving means, and the printing roll and the backup roll are opposed to each other with a gap allowing the semicircular arc member to pass therethrough. An apparatus for manufacturing a coated bearing, characterized in that: Means for storing the accumulated rotational speed of the transfer roll and the printing roll rotating in contact with each other, separating the transfer roll and the printing roll when the cumulative rotational speed reaches a predetermined number of times, and bringing the printing roll and the backup roll closer to each other 7. The apparatus for manufacturing a coated bearing according to claim 6, further comprising means for issuing a roll movement command.

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