Machining method of plastic and metal duplex planetary gear

Abstract

According to the machining method of the plastic and metal duplex planetary gear, machining of the metal gear part is completed firstly, the inner hole and the pin hole which are in interference fit with the metal gear are pre-machined in the plastic part through turning and milling, after press fitting is completed, gear machining of the plastic part is completed through a gear hobbing machine in a machining mode, mold opening is not needed, the degree of freedom is high, and the machining efficiency is high. The die development cost can be avoided, the development cost is greatly reduced, the development period is shortened, and the method is very suitable for the situation that product parameters are frequently changed in the new product research, development and verification stage and suitable for early-stage single-piece small-batch production.

Description

Technical Field

[0001] The invention relates to a processing method of a plastic and metal double planetary gear, which mainly uses a centrally mounted bicycle planetary mechanism transmission component. Background Art

[0002] With the rapid development of plastics as basic industrial materials in the industrial field, the strength and toughness of plastics have been improved, the meshing noise has been low, and the manufacturing process has been improved. More and more product structural parts use plastics to replace metal materials. Plastic gears have the advantages of self-lubrication, low inertia, low noise, and corrosion. In some scenarios, they have better application effects than metal gears. They are more widely used in people's livelihood fields such as micro motors, electronic products, auto parts, household appliances, office supplies, toys, and handicrafts. Due to market demand and innovations in gear design concepts, some mechanical transmission mechanisms currently have double gears that are a combination of metal and plastic. According to the conventional processing strategy, after the metal gear part is processed, the plastic gear part is processed by injection molding through the mold. However, in the early test stage of new product development, the gear parameters need to be adjusted many times during the verification process. The conventional processing method requires the mold to be repaired or even re-manufactured after the parameters are adjusted, which will greatly increase the production cost and processing cycle. Injection molding is not suitable for single-piece small-batch production. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and to provide a processing method for plastic and metal double planetary gears that does not require mold opening and has a high degree of freedom. This method can cope with the situation where product parameters are frequently changed during the research and development and verification stage of new products, shorten the processing cycle, and reduce production costs.

[0004] The processing method of the plastic and metal double planetary gear of the present invention is: S1: Select the processed metal gears, plastic parts with other dimensions processed except the gear parts, and metal pins; S2: Press-fit the plastic part and the metal gear, press the metal gear into the inner hole of the plastic part, and ensure that the pin hole of the plastic part is aligned with the pin hole of the metal gear; S3: Press-fit the metal pin. Press the metal pin into the pin hole to prevent the metal pin from tilting during the press-fitting process. The metal pin must not protrude after the press-fitting is completed. S4: After the press-fitting is completed, the tooth processing of the plastic part is completed on the gear hobbing machine.

[0005] The plastic part of the present invention is pre-processed with an inner hole which is interference-fitted with the metal gear.

[0006] The plastic part of the present invention is pre-processed with a plastic part pin hole, and the pin hole is interference-fitted with the pin hole of the metal gear.

[0007] The plastic part of the present invention is made of bar material.

[0008] The patent of the present invention mainly uses the transmission components of the central bicycle planetary mechanism, and generally adopts a double planetary structure composed of plastic PEEK gears and metal planetary gears. If the metal gears are made and then the PEEK gears are injected, the mold cost is quite high, and the parameters of the early development products are not locked. The gear parameters need to be adjusted many times during the verification process. The conventional processing method needs to repair the mold or even re-manufacture the mold after adjusting the parameters, which will greatly increase the production cost and processing cycle, and is not suitable for single-piece small-batch production. The present invention first completes the processing of the metal gear part, and the plastic parts are pre-processed by turning and milling to obtain the inner holes and pin holes that are interference-fit with the metal gears. After the press-fitting is completed, the gear processing of the plastic parts is completed by machining using a gear hobbing machine. In this way, there is no need to open the mold, the degree of freedom is high, the cost of mold development can be avoided, the development cost is greatly reduced, and the development cycle is shortened. It is very suitable for the situation where product parameters are frequently changed in the new product development and verification stage, and it is suitable for early single-piece small-batch production. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the press-fitting process of an embodiment of the present invention.

[0010] Figure 2 Schematic diagram of the finished product of the embodiment of the present invention.

[0011] In the figure: metal gear 1; plastic part 2; metal pin 3; inner hole 4; plastic part pin hole 5; metal gear pin hole 6. DETAILED DESCRIPTION

[0012] The present invention will be further described in detail below in conjunction with device photos and examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0013] Example: See also Figure 1-2 The processing method of the plastic and metal double planetary gears in this embodiment is: S1: Select a processed metal gear 1, a plastic part 2 whose other dimensions have been processed except the tooth part, and a metal pin 3; S2: Press-fit the plastic part 2 and the metal gear 1, press the metal gear 1 into the inner hole 4 of the plastic part 2, and ensure that the pin hole 5 of the plastic part is aligned with the pin hole 6 of the metal gear; S3: Press-fit the metal pin 3. Press the metal pin 3 into the pin hole to prevent the metal pin 3 from tilting during the press-fitting process. The metal pin 3 must not protrude after the press-fitting is completed.

[0014] S4: After the press-fitting is completed, the 2 teeth of the plastic part are processed on the gear hobbing machine.

[0015] In this embodiment, the plastic part 2 is pre-machined with an inner hole 4 which is interference-fitted with the metal gear 1 .

[0016] In this embodiment, the plastic part is pre-processed with a plastic part pin hole 5, and the pin hole is interference fit with the metal gear pin hole 6.

[0017] In this embodiment, the plastic part 2 is made of bar material.

[0018] In this embodiment, the metal gear 1 is partially processed first, and the plastic part 2 is pre-processed by turning and milling to form an inner hole and a pin hole that are interference fit with the metal gear 1. After the press-fitting is completed, the gear processing of the plastic part 2 is completed by machining using a gear hobbing machine. There is no need to open a mold, and the degree of freedom is high. The cost of mold development can be avoided, the development cost is greatly reduced, and the development cycle is shortened. It is very suitable for the situation where product parameters are frequently changed in the new product research and development verification stage, and is suitable for early single-piece small-batch production.

[0019] In addition, it should be noted that any equivalent changes or simple changes made based on the structure, features and principles of the patent concept of the present invention are included in the protection scope of the patent of the present invention.

Claims

1. A method for processing plastic and metal double planetary gears, characterized in that: S1: Select the processed metal gears, plastic parts with other dimensions processed except the gear parts, and metal pins; S2: Press-fit the plastic part and the metal gear, press the metal gear into the inner hole of the plastic part, and ensure that the pin hole of the plastic part is aligned with the pin hole of the metal gear; S3: Press-fit the metal pin. Press the metal pin into the pin hole to prevent the metal pin from tilting during the press-fitting process. The metal pin must not protrude after the press-fitting is completed. S4: After the press-fitting is completed, the tooth processing of the plastic part is completed on the gear hobbing machine.

2. The method for processing a plastic and metal double planetary gear according to claim 1, characterized in that: The plastic part is pre-processed with an inner hole which is interference-fitted with the metal gear.

3. The method for processing a plastic or metal double planetary gear according to claim 1, characterized in that: The plastic part is pre-processed with a plastic part pin hole, and the pin hole is interference-fitted with the metal gear pin hole.

4. The method for processing a plastic or metal double planetary gear according to claim 1, characterized in that: The plastic part is made of bar material.

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