JPS5933469B2 - Method of forming a wear-resistant surface on metal parts - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for forming a wear-resistant surface on a metal member formed by a pressure casting method or a die-casting method, and in particular a method for forming an unfired self-lubricating wear-resistant synthetic resin powder on a metal surface. The present invention relates to a method of baking and hardening the resin at the same time as bonding, and then re-baking it at around the gelling temperature of the resin to obtain a predetermined surface hardness.

Conventionally, a method has been adopted to improve wear resistance by adhering a fired Teflon sheet containing a filler to the sliding portion of a metal member.

Epoxy adhesives, thermoplastic film adhesives, and the like are used to bond these sheets together. However, in the former case, it is necessary to apply a fixed pressure to the object to be adhered and leave it to cure for the time required for adhesion at room temperature or after raising the temperature, whereas in the latter case, a film of adhesive is sandwiched between the interface and cure By bolting or hot press method through tools,
It was necessary to heat the film to its melting point and then cool it down to complete the bonding process. That is, these operations required a lot of manual work, required adhesives and equipment for heating and pressurizing, and were inefficient as one bonding operation took a long time.
Furthermore, since a fired sheet or the like is used, there is a drawback that it is difficult to form the surface into a complicated shape. The filler-containing Teflon sheet is made by heating and pressurizing unfired powder of filler-containing Teflon or the like.

Therefore, when unfired powder is heated and pressurized with molten metal,
The sheet can be formed at the same time as firing. Furthermore, when unfired filler-containing Teflon powder is heated and pressurized at a certain temperature, it has the property of being hardened and mechanically bonded to a metal member at the same time. Furthermore, since the sheet raw material is an unfired powder, it can be filled into a mold having irregularities. This invention focuses on the manufacturing method of the filler-containing Teflon sheet and the properties of the raw materials, and utilizes the temperature and pressure during the process of forming a metal member by pressure casting or die casting, and simultaneously forms the metal member. It is an object of the present invention to provide a method for forming a layer of filled Teflon or the like having wear resistance on the surface without using an adhesive and in one step. , b is as follows. In Figure 1, 1 is a cylinder, 2 is a lower mold, 3 is an upper mold for pressurization attached to the plunger of a hydraulic press, and 4 is a mold that has wear resistance, self-lubricating properties, and is resistant to high temperatures. Powder such as Teflon with unfired filler that can withstand
5 is a metallic disk that prevents scattering of powder in the mold by pouring molten metal and also firmly integrates the aluminum alloy or zinc alloy and the resin layer after firing and hardening; The plate is made of a metal material that alloys with a low melting point below the temperature of the molten metal, such as lead.

6 is a low melting point metal such as aluminum alloy or zinc alloy, 7
8 is a knock-out pin for taking out the cast product and the lower mold 2 from the cylinder 1, and 9 is a band heater for keeping the cylinder 1 warm and relaxing the cooling rate gradient of the molten metal 6 after pouring. .

The amount of unfired powder 4 to be filled is arbitrary depending on the required thickness of the layer. As the filling powder, unfired polyimide resin powder may be used in addition to Teflon or filler-containing Teflon. This invention is carried out in the following manner.

That is, unfired powder 4 is filled into the mold, then a metal disk 5 is inserted, and molten metal 6 is injected. When the molten metal 6 is injected, the upper mold 3 is lowered almost simultaneously to perform pressure molding. Then, the powder 4 is joined by the heat of the molten metal 6 and the pressure of the upper mold 3, and is fired as the molten metal 6 solidifies and cools, and the disk 5 is melted by the heat of the molten metal 6 and mechanically connects with the fired resin layer. The molten metal of the disk and the molten metal of aluminum alloy or the like are solidified and cooled to form an alloy, and as a result, the fired resin layer is bonded to the metal surface. Next, after cooling, the knockout 7 rises and transfers the product and the lower mold 2 to the cylinder 1.
The product and the lower mold 2 are separated using the knockout pin 8. The outer diameter and surface layer of the product will be machined as necessary. Figure 2a shows a front view of a case in which predetermined irregularities 10 are formed on the surface of a metal product to be cast at the same time as the molding, and a fired layer of filler-containing Teflon or the like is simultaneously formed along the irregularities. show.

FIG. 2b is a partial cross-section of the product. When the unfired powder is heated and pressurized by the molten metal, plastic flow of the powder occurs, resulting in a state in which the molten metal and the powder in the disk are intricately intertwined. That is, by using the molten metal in which the disc is melted, mechanical joining becomes possible through entanglement with the powder. In addition, the disk is alloyed at the contact surface between the molten metal and the molten aluminum alloy to firmly integrate the two into one, and as a result, the resin layer and the aluminum alloy are integrated into one. At the same time as this bonding, the powder is hardened, but since the hardness of this hardened layer has not yet reached the specified surface hardness, it is baked again at around the gelling temperature of the resin to achieve the specified surface hardness. It is necessary to. Note that 11 is the melted and solidified layer of the disk. As explained above, the present invention provides a method for integrally forming a self-lubricating, wear-resistant synthetic resin surface layer on a metal sliding surface, in which unfired self-lubricating, wear-resistant synthetic resin powder such as polytetrafluoroethylene is placed in a mold. Then, a metal plate of a predetermined thickness made of a material that is alloyed at a low melting point below the molten metal temperature of a low melting point alloy such as an aluminum alloy or a zinc alloy is inserted, and then a metal plate material of a predetermined thickness is inserted. The unfired powder is fired and hardened at the same time as bonding by injecting a molten metal of a low melting point alloy consisting of the above resin and press-forming it with an upper mold after injection.The solidified metal member is taken out from the mold, and finally the resin is Since the resin surface layer is re-fired at around the gelation temperature to a predetermined surface hardness, it is extremely easy and reliable to mold Teflon or filled Teflon onto the surface of the metal member at the same time. can.

In this case, the temperature of the injected molten metal is higher than the melting point and firing temperature of the resin powder filled in the mold, but since the molding in the mold is done in a very short time, the resin surface There is no need to worry about heat damage to the layers. In addition, by adjusting the thickness of the metal plate used, the amount of thermal energy absorbed for alloying with the molten metal changes, making it possible to provide the appropriate temperature for firing the resin powder and bonding it to the metal surface. can. Further, the method of the present invention can simultaneously form an uneven shape on a metal surface, and perform baking and bonding of the resin surface layer along the unevenness, and does not require an adhesive.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2A
, b are a plan view and a sectional view of a metal member showing the uneven shape of the surface formed at the same time as molding. 1...Cylinder, 2...Lower die, 3...
... Upper mold, 4... Unfired resin powder, 5.
...Metal plate, 6.. Molten metal of low alloy, 1.. Knock out, 8.. Knock out pin, 9.. band heater.

Claims (1)

[Claims] 1. In a method of integrally forming a self-lubricating, wear-resistant synthetic resin surface layer on a metal sliding surface, a mold is filled with unfired self-lubricating, wear-resistant synthetic resin powder such as polytetrafluoroethylene, and then an aluminum alloy or zinc A metal plate of a predetermined thickness made of a material that alloys at a low melting point below the temperature of a molten metal of a low melting point alloy made of an alloy, etc. is inserted, and then a molten metal of a low melting point alloy made of an aluminum alloy, a zinc alloy, etc. is injected. After injection, the unfired powder is baked and hardened at the same time as bonding by pressure molding with an upper mold, the solidified metal member is taken out from the mold, and finally it is refired at around the gelling temperature of the resin to form the resin. 1. A method for forming a wear-resistant surface on a metal member, the method comprising forming a surface layer to a predetermined surface hardness.