JPH0758094B2 - Oil-impregnated bearing manufacturing method - Google Patents

Description

Detailed Description of the Invention a. Object of the Invention (Industrial field of application) The present invention relates to a method for manufacturing an oil-impregnated bearing which is used in the oil-impregnated bearing manufacturing industry and which increases the amount of oil-retention and the duration of oil-retention.

(Prior Art) Conventional metal powder is pressure-molded in a mold and then sintered to form a porous sintered body, and the pores thereof are further impregnated with a lubricating medium such as oil. Impregnated bearings are already known.

The conventionally known sintered oil-impregnated bearing is, as shown in the block diagram of FIG. 8, a fine particle of a copper or iron bearing material alone, or a mixing step A for uniformly mixing several kinds of materials, The pressure-forming step B in which the mixed material is compression-formed by a die and pressure-formed, the firing step C in which the pressure-forming step B is fired at a high temperature in a sintering furnace, and the sintering step It was manufactured through a manufacturing process including a straightening and machining process D for performing dimension correction and partial machining, and a lubricating medium impregnation process E for impregnating the porous portion of the bearing with oil.

(Problems to be solved by the invention) However, in the conventional oil-impregnated bearing, when the shaft rotates while contacting the bearing during use, the oil impregnated in the hole of the bearing leaks out to cause a gap between the bearing and the shaft. An oil film is formed on the surface, and the oil film intervenes to lubricate the oil so that it can rotate smoothly. Therefore, it is an important point how much the lubricating medium is impregnated with oil in the lubricating medium. If the value is too large, the lubricating medium, oil, is scattered and the oil disappears quickly.

On the other hand, if the holes are too small, the oil of the lubricating medium does not flow out as desired, making the oil film structure difficult, causing problems such as seizure of the bearing.

As a method of increasing the oil content recently, a means of providing an oil reservoir device in contact with the bearing has been considered and already implemented as a method for solving the above problems.However, in the case of this oil reservoir device, its configuration becomes complicated and It has a problem that it becomes expensive.

The present invention has been made in order to solve the above-mentioned conventional problems. After the firing step, an etching agent impregnation step, a first cleaning step for removing the etching agent on the bearing surface portion and the shallow hole portion, and an etching step are performed. The second cleaning step of removing the etching agent, the step of impregnating the lubricating medium, or the step of adding a masking step for preventing the outflow of the etching agent and the masking removing step during the step. It is an object of the present invention to provide an oil-impregnated bearing manufacturing method capable of manufacturing an inexpensive oil-impregnated bearing capable of increasing the oil content and maintaining the oil retention time.

B. Configuration of the Invention (Means for Solving the Problems) A method for manufacturing an oil-impregnated bearing according to the present invention for achieving the above-mentioned object is as shown in FIG. In the manufacturing method, after the firing step c, an etching agent impregnation step d in which the hole 4 is impregnated with the etching agent 5, and after the etching agent impregnation step d, the bearing surface portion 2 and the shallow hole portion 4 are formed.
First cleaning step e for removing the etching agent 5 in step 1, an etching step f for performing etching with the etching agent 5 after the first cleaning step e, and a second cleaning step for removing the etching agent 5 after the etching step f. The oil-impregnated bearing is manufactured by step g and each step of the lubricating medium impregnating step h of impregnating the entire hole 4 with the lubricating medium 8 after the second washing step g.

The method for producing an oil-impregnated bearing according to the second aspect of the present invention is the sixth aspect.
As shown in the figure, in the method for manufacturing a porous oil-impregnated bearing, after the firing step c ′, an etching agent impregnation step d ′ for impregnating the hole with an etching agent, and after the etching agent impregnation step d ′,
First to remove the etching agent on the bearing surface and the shallow hole
After the cleaning step e ', after the first cleaning step e', a masking step i for masking the surface portion and the shallow layer hole portion to prevent the etching agent from flowing out inside the hole, and an etching step f for etching with the etching agent. ', A masking removal step j for removing the masking agent, and a second cleaning step g'for removing the etching agent after the masking removal.
After the second cleaning step g ', the oil-impregnated bearing is manufactured through each step of the lubricating medium impregnating step h'of impregnating the entire hole with the lubricating medium.

(Operation) In the use of the oil-impregnated bearing manufactured by the method for manufacturing an oil-impregnated bearing according to the present invention, when the oil-impregnated bearing is used for a micromotor or the like of an audio device such as an audio device, it supports the rotating shaft. Then, when the shaft rotates, the oil of the lubricating medium 8 impregnated in the porous portion of the oil-impregnated bearing 1 flows out to form an oil film between the oil-impregnated bearing and the shaft for lubrication.

At this time, the oil film is initially formed by the oil accumulated in the bearing surface portion 2 and the shallow hole portion 4, and the oil film is later formed by the oil 8 accumulated in the hole 7 of the bearing deep layer portion 6 for increasing the oil content, and is always stable. By supplying the oil, a long-life oil-impregnated bearing can be manufactured.

(Example) Example. Next, an embodiment of a method for manufacturing an oil-impregnated bearing according to the present invention will be described with reference to FIGS. 1 to 5.

FIG. 1 is a block diagram showing a manufacturing process in this embodiment, FIG. 2 is a sectional view of an oil-impregnated bearing obtained by this method, and FIGS. 3 to 5 are oil-impregnated bearings in each process. It is an expanded sectional view showing the important section.

(A) Mixing step: Fine particles (copper bearings) of copper powder, lead powder, tin powder, and graphite powder are mixed in a mixer or mixed, or a bearing forming material made of iron powder, copper powder, lead powder, and graphite powder ( Pour the iron-based bearing) into the mixer.

(B) Molding step: The mixed bearing-forming material is compression-molded with a mold to form a bearing 1.
To form.

(C) Firing step: The green compact is placed in a high-temperature firing furnace and sintered.

(D) Step of impregnating the etching agent; a step of impregnating the inside of the bearing 1 with the etching agent 5 from the shallow layer hole portion 4 in the shallow layer portion 3 of the bearing surface portion 2 of the fired bearing 1 by the etching agent 5 Is ferric chloride or the like, which is vacuum impregnated.

(E) First cleaning step; a step of cleaning the etching agent 5 adhering to the surface portion 2 and the shallow layer hole portion 4 of the bearing 1 in the etching agent impregnation step, which is the surface portion 2 and the shallow layer hole portion. Immediately wash with water or an organic solvent so that 4 is not etched.

(F) Etching step: a step of corroding an iron or copper-based metal portion with the impregnated etching agent 5 to form a large hole 7 in the deep layer portion 6 of the bearing 1, the amount of etching being time and the etching agent. It is controlled by the concentration or temperature of.

(G) Second cleaning step; in the step of removing the impregnated etching agent 5, the bearing 1
Is washed again with a cleaning agent composed of water or an organic solvent, and the etching agent 5 is removed and dried.

(H) Lubrication medium impregnation step: The bearing surface portion 2 and the shallow layer portion 4 of the shallow layer portion 3 are small holes, and the holes 7 of the deep layer portion 6 are large holes, which are uniform over the entire hole portion of the porous bearing 1. Is impregnated with the lubricating medium 8 anderol oil.

In this impregnation, the bearing 1 is placed in an impregnation tank, the inside of the tank is deaerated in vacuum, and then the anderol oil is injected into the tank, which is held for a certain period of time to impregnate the underroll oil. .

As described above, according to the present invention, in the porous oil-impregnated bearing, the shallow surface hole portion 4 of the bearing surface portion 2 and the shallow layer portion 3 through which the lubricating medium 8 flows out.
Is a small hole, and the hole 7 of the deep layer portion 6 is a large hole, and the uniform porous portion is impregnated with the lubricating medium 8.

Embodiment 2. Next, an embodiment of the second invention will be described with reference to the block diagram of FIG.

(A ') Mixing step: Fine particles (copper bearings) of copper powder, lead powder, tin powder, graphite powder are mixed in a mixer or mixed, or a bearing forming material composed of iron powder, copper powder, lead powder, graphite powder Add (iron bearing) to the mixer.

(B ') Molding step: The mixed bearing forming material is compression-molded with a mold to form a bearing.

(C ') Firing step: In the molding step, the powder compact formed into the shape of a bearing is put into a firing furnace in which the inside of the furnace has a high temperature and sintered.

(D ') Etching agent impregnating step: In the step of impregnating the inside of the bearing with the etching agent through the holes formed on the surface of the bearing, ferric chloride or the like is used as the etching agent and impregnated in vacuum.

(E ') First cleaning step; a step of cleaning the etching agent adhering to the holes in the surface portion and the shallow layer portion of the bearing in the etching agent impregnation step so that the surface portion and the shallow layer hole portion are not etched. Immediately wash with water or organic solvent.

(I) Masking step: After the first cleaning step, the surface portion of the formed bearing and the hole in the shallow layer portion close to the surface portion, that is, the shallow layer hole portion are closed with a masking agent 9 such as an acrylic resin solution, and an etching agent. To prevent the outflow to the outside.

(F ') Etching step: This is a step for corroding an iron or copper-based metal part to form a large hole in the deep layer part of the bearing, and the amount of etching is controlled by time and the concentration or temperature of the etching agent.

(J) Masking removal step: After etching is completed, the masking resin film applied to the bearing surface portion and the shallow hole portion is peeled off. At this time, when a resin film is formed using the acrylic resin agent, the film is removed with an alkaline solution.

(G ') Second washing step: After the resin film is removed by the masking removing step, the attached film removing agent and etching agent are washed away again with a washing solution composed of water or an organic solvent, and the others are removed and dried. .

(H ′) Lubrication medium impregnation step: The holes in the bearing surface portion and the shallow layer portion of the formed bearing are made small,
A hole in a porous bearing having large holes formed in the deep layer is impregnated with Anderol oil as a lubricating medium.

In this impregnation, the bearing is put in an impregnation tank, the inside of the impregnation tank is vacuumed and degassed, and then Anderol oil is injected into the tank and kept for a certain period of time to impregnate the Anderol oil.

In the above porous oil-impregnated bearing, the holes on the bearing surface and the shallow layer where the lubricating medium flows out are made into the optimal small holes according to the purpose of use as it was formed during firing, and the holes in the deep layer are etched. The large pores are impregnated with a lubricating medium to the lubrication medium, and the oil retention is large, and the oil outflow can reach the required amount from the small pores in the shallow layer, thus maintaining the oil retention time. The intended oil-impregnated bearing can be obtained.

C. EFFECTS OF THE INVENTION Since the method for manufacturing an oil-impregnated bearing according to the present invention is configured as described above, the oil-impregnated bearing obtained by this method is used as an oil as a lubricating medium for a large hole formed in a deep layer of the formed bearing. Since the oil can be stored, the oil content is greatly increased compared to the conventional oil-impregnated bearing, and at the same time, the outflow of this impregnated oil can be maintained at the optimum value through the small holes in the shallow layer, It is possible to obtain a stable and long-life oil-impregnated bearing.

In assembling the formed bearing, when a housing case or the like is press-fitted when it is mounted on a bearing device, the hole portion formed in the deep layer of the bearing also absorbs the press-fitting strain, so that it is generally used conventionally. When the sizing bottle press-fitting method used is used, it is possible to suppress the variation in the inner diameter.

It has unique effects such as.

Further, in the porous oil-impregnated bearing according to the second invention of the present application, after the firing step, the etching agent on the surface portion and the shallow layer hole portion of the formed bearing is washed or washed, and then the etching agent is prevented from flowing out by the masking agent. In the case where the etching is performed after the above, it is possible to prevent the etching agent from flowing out to the bearing surface portion and the shallow layer hole portion, so that the shallow layer hole portion can be completely prevented from being etched. Since the small holes formed during firing can be retained, the amount of oil required when using the bearing can be reliably supplied.

In the etching process, by adjusting the concentration of the etching solution and the etching time, the size of the holes in the deep layer portion can be made the optimum size. Therefore, it is possible to obtain an oil-impregnated amount according to the intended use, so that a high-performance oil-impregnated bearing can be provided at low cost.

It has a unique effect such as.

[Brief description of drawings]

Drawing FIG. 1 is a block diagram showing a method for manufacturing an oil-impregnated bearing according to the present invention, FIG. 2 is a cross-sectional view of an oil-impregnated bearing formed by this manufacturing method, and FIG. 3 is an etching in an upper manufacturing process. FIG. 4 is an enlarged cross-sectional view of the main part showing the part that is and is not, and FIG. 4 is an enlarged cross-sectional view of the main part after oil impregnation.
FIG. 5 is an enlarged cross-sectional view of an essential part showing a state after the first cleaning step from the etching agent impregnation step, FIG. 6 is a block diagram showing a method for manufacturing an oil-impregnated bearing according to the second invention, and FIG. 7 is an upper masking. FIG. 8 is an enlarged cross-sectional view of an essential part showing a state after the process, and FIG. 8 is a block diagram showing a manufacturing process of a conventional oil-impregnated bearing. In the figure, 1 is a bearing, 2 is a bearing surface view, 3 is a shallow layer portion, 4 is a shallow layer hole portion, 5 is an etching agent, 8 is a lubricating medium, 9 is a masking agent, and (a) and (a ') are mixed. Steps, (b) and (b ') are molding steps, (c) and (c') are firing steps, and (d) and (d ').
Is an etching agent impregnation step, (e) and (e ') are first cleaning steps, (f) and (f') are etching steps, and (g) and (g ') are
Is the second cleaning step, (h) and (h ') are the lubricating medium impregnation step,
(I) is a masking step, and (j) is a masking removal step.

Claims (2)

[Claims] 1. In a method for producing a porous oil-impregnated bearing, an etching agent impregnation step of impregnating the hole with an etching agent after a firing step, and a bearing surface portion and a shallow layer hole portion after the etching agent impregnation step. First cleaning step of removing the etching agent, the etching step of performing etching with the etching agent after the first cleaning step, the second cleaning step of removing the etching agent after the etching step, and the second cleaning step. And a lubricating medium impregnation step of impregnating the entire rear hole portion with a lubricating medium. 2. In a method for producing a porous oil-impregnated bearing, an etching agent impregnation step of impregnating the hole portion with an etching agent after the firing step, and a bearing surface portion and a shallow layer hole portion after the etching agent impregnation step. First cleaning step of removing the etching agent of step (1), and a masking step of masking the surface portion and the shallow layer hole portion for preventing the outflow of the etching agent inside the hole, and etching is performed by the etching agent after the first cleaning step. An etching step, a masking removal step of removing the masking agent after the etching step, a second cleaning step of removing the etching agent after the masking removal step, and a second
A method of manufacturing an oil-impregnated bearing, comprising a lubricating medium impregnation step of impregnating the entire hole with a lubricating medium after the washing step.