Machining method of plastic gear
Through the double hob processing method, cutting from the opposite end faces of the plastic gear is done separately, which solves the problem of difficult burrs after the plastic gear hob machine processing, and achieves high-precision and smooth gear end faces, improving product quality.
Patent Information
- Application Number
- CN202510784792.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-07-22
AI Technical Summary
In the prior art, it is difficult to completely remove burrs after the gear hobbing machine, resulting in insufficient accuracy and affecting product quality.
The double hob processing method is adopted to cut from the opposite end faces of the plastic gear. The rotation directions of the first hob and the second hob are opposite. They are screwed in and cut from the first and second end faces of the plastic workpiece to be processed to a designated position and then stopped rotating and retracting the tool to ensure that the cutting trajectory matches and the depth is consistent.
It effectively avoids the occurrence of burrs on the end face of plastic gears, improves product quality and production efficiency, ensures that the end face of the gears is smooth and burrs free, and meets high-precision requirements.
Smart Images
Figure CN120347293A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of gear processing, and particularly relates to a processing method for plastic gears. Background Art
[0002] Small module plastic gears are generally injection molded. The advantages of injection molding are high processing efficiency, smooth tooth surfaces and end faces without burrs. The disadvantage is that the accuracy is generally two levels lower than that of hobbing machines. For plastic gears with high accuracy requirements, hobbing machines are the first choice.
[0003] Due to the characteristics of plastics (such as POM, nylon, etc.), after the plastic gear blanks are processed by ordinary hobbing, a large number of burrs will be generated on the cutting surface of the hob. The mechanism of burr generation is as follows:
[0004] During the cutting process of the workpiece material, it is continuously peeled off from the base by the hob. When the hob is about to leave the workpiece, the material at the end of the workpiece begins to extend and undergoes severe plastic deformation. When the hob cuts out the end of the workpiece, due to the low support strength at the end of the workpiece, plastic bending deformation and plastic shear slip deformation occur, and finally remain on the end face of the workpiece to form burrs.
[0005] Currently, the methods of cryogenic deburring and dry ice deburring are commonly used for plastic products, but neither can completely remove the burrs. Under a magnifying glass, it can still be seen that there are burrs tightly connected to the base remaining on one tooth surface. Summary of the Invention
[0006] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a processing method for plastic gears, aiming to solve the problem that burrs are generated on plastic gears by the current hobbing method.
[0007] To achieve the above purpose, the present invention adopts the following technical solutions:
[0008] The present invention provides a processing method for plastic gears, which is processed by a gear processing device. The gear processing device includes a first hob and a second hob. The method includes:
[0009] The first hob rotates in a first rotation direction and enters and cuts from the first end face of the plastic workpiece to be processed. When the first hob enters and cuts to the first position of the plastic workpiece to be processed, stop the rotation of the first hob and retract the tool;
[0010] The second hob rotates in a second rotation direction and enters and cuts from the second end face of the plastic workpiece to be processed. When the second hob enters and cuts to the second position of the plastic workpiece to be processed, stop the rotation of the second hob and retract the tool;
[0011] Wherein, the first end face and the second end face are two opposite end faces of the plastic workpiece to be processed.
[0012] Furthermore, during the process that the first hob rotates into and cuts to the first position from the first end face of the plastic workpiece to be machined, the plastic workpiece to be machined maintains the second rotation direction.
[0013] Furthermore, during the process that the second hob rotates into and cuts to the second position from the second end face of the plastic workpiece to be machined, the plastic workpiece to be machined maintains the first rotation direction.
[0014] Furthermore, the first rotation direction and the second rotation direction are opposite.
[0015] Furthermore, the first rotation direction is the clockwise direction and the second rotation direction is the counterclockwise direction, or the first rotation direction is the counterclockwise direction and the second rotation direction is the clockwise direction.
[0016] Furthermore, the second position coincides with the first position.
[0017] Furthermore, the second position is located between the stroke from the first end face to the first position.
[0018] Furthermore, the front end faces of the first hob and the second hob are arranged oppositely.
[0019] Furthermore, the hob parameters of the first hob and the second hob are the same.
[0020] Furthermore, the hob parameters include module, pressure angle, helix angle, number of teeth, outer diameter, root diameter and tooth thickness.
[0021] The beneficial effects of the present invention compared with the prior art are as follows: a processing method of a plastic gear is provided, which is processed by a gear processing device including a first hob and a second hob. The method includes: the first hob rotates into and cuts from the first end face of the plastic workpiece to be machined while maintaining the first rotation direction, and stops rotating and retracts the tool when the first hob rotates into and cuts to the first position of the plastic workpiece to be machined; the second hob rotates into and cuts from the second end face of the plastic workpiece to be machined while maintaining the second rotation direction, and stops rotating and retracts the tool when the second hob rotates into and cuts to the second position of the plastic workpiece to be machined; wherein, the first end face and the second end face are two opposite end faces of the plastic workpiece to be machined. By adopting the double-hob method, the present invention respectively performs cutting processing from two opposite ends of the plastic workpiece to be machined, thereby avoiding the problem of end face burrs on the plastic gear after processing and improving the quality of the plastic gear.
[0022] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically described as follows. Description of the Drawings
[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0024] Figure 1 It is a schematic diagram of a plastic gear processed by hobbing in the prior art before deburring;
[0025] Figure 2 It is a schematic diagram of a plastic gear after deburring with dry ice in the prior art;
[0026] Figure 3 It is a schematic structural diagram of a gear processing device provided by a specific embodiment of the present invention;
[0027] Figure 4 It is a partially enlarged view of the gear processing device provided by a specific embodiment of the present invention;
[0028] Figure 5 It is a flowchart of a processing method for a plastic gear provided by a specific embodiment of the present invention;
[0029] Figure 6 It is a partial schematic diagram of a plastic gear processed by a processing method for a plastic gear of the present invention.
[0030] Reference numerals
[0031] 1, hob spindle; 2, workpiece rotation spindle; 3, tailstock rotation spindle; 4, first hob; 5, second hob; 100, plastic workpiece to be processed. Specific embodiments
[0032] The following will combine specific embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.
[0033] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present invention.
[0034] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.
[0035] In the present invention, unless otherwise clearly defined and limited, terms such as "mounted", "connected", "coupled", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0036] In the present invention, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.
[0037] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation.
[0038] Small module plastic gears are generally injection molded. The advantages of injection molding are high processing efficiency and smooth tooth surfaces and end faces without burrs. The disadvantage is that the accuracy is generally two levels lower than that processed by hobbing machines. For plastic gears with high precision requirements, hobbing machine processing is the first choice.
[0039] Due to the characteristics of plastics themselves (such as POM, nylon, etc.), after the plastic gear blank is processed by ordinary hobbing, a large amount of burrs will be generated on the cut surface of the hob. The mechanism of burr generation is as follows:
[0040] During the cutting process of the workpiece material, it is continuously peeled off from the substrate by the hob. When the hob is about to leave the workpiece, the material at the end of the workpiece begins to extend and undergoes severe plastic deformation. When the hob cuts out the end of the workpiece, due to the low support strength at the end of the workpiece, plastic bending deformation and plastic shear slip deformation occur, as Figure 1 shown, and finally burrs are left on the end face of the workpiece.
[0041] Currently, the common methods for deburring plastic products are cryogenic deburring and dry ice deburring, but neither can completely remove the burrs. As Figure 2 shown, under a magnifying glass, it can still be seen that there are burrs tightly connected to the substrate remaining on one tooth surface. Based on this problem, the present invention is proposed. The present invention will be introduced below through specific embodiments.
[0042] An embodiment of the present invention provides a processing method for plastic gears, which is processed by a gear processing device. As Figure 3 and Figure 4 shown, the gear processing device includes a hob spindle 1, a first hob 4, a second hob 5, a workpiece rotation spindle 2 and a tailstock rotation spindle 3. The hob spindle 1 is used to install the hob and drive it to rotate to achieve the cutting motion. The first hob 4 and the second hob 5 are cutting tools. The workpiece rotation spindle 2 fixes the plastic workpiece 100 to be processed and drives it to rotate to cooperate with the hob for cutting. The tailstock rotation spindle 3 assists in supporting the other end of the plastic workpiece 100 to be processed to ensure the stability during the processing.
[0043] As Figure 5 shown, the processing method for plastic gears includes the following steps: S10 - S20.
[0044] S10. The first hob 4 rotates in the first rotation direction and cuts into the first end face of the plastic workpiece 100 to be machined. When the first hob 4 rotates in and cuts to the first position of the plastic workpiece 100 to be machined, stop the rotation of the first hob 4 and retract the tool.
[0045] Install the plastic workpiece 100 to be machined on the fixture of the workpiece rotating spindle 2. The tailstock center of the tailstock rotating spindle 3 presses against the second end face of the workpiece. Adjust the positions of the workpiece rotating spindle 2, the tailstock rotating spindle 3, and the hob spindle 1 to ensure that the plastic workpiece 100 to be machined forms a certain angle with the axis of the first hob 4.
[0046] When starting cutting, move the first hob 4 to the cutting position, start the first hob 4 to make it rotate in the first rotation direction, and at the same time start the workpiece rotating spindle 2 to make the plastic workpiece 100 to be machined rotate in the second rotation direction. When the first hob 4 rotates in and cuts to the first position of the plastic workpiece 100 to be machined from the first end face, stop the rotation of the first hob 4, and control the first hob 4 to retract along the original path to the initial position.
[0047] S20. The second hob 5 rotates in the second rotation direction and cuts into the second end face of the plastic workpiece 100 to be machined. When the second hob 5 rotates in and cuts to the second position of the plastic workpiece 100 to be machined, stop the rotation of the second hob 5 and retract the tool, where the first end face and the second end face are two opposite end faces of the plastic workpiece 100 to be machined.
[0048] After the first hob 4 has completed retracting the tool, move the second hob 5 to the cutting position and start it to make it rotate in the second rotation direction. At the same time, adjust the rotation direction of the workpiece rotating spindle 2 to the first rotation direction, and keep the rotation speed the same as that when being cut by the first hob 4. When the second hob 5 rotates in and cuts to the second position of the plastic workpiece 100 to be machined from the second end face, stop the rotation of the second hob 5, and control the second hob 5 to retract along the original path to the initial position.
[0049] For steps S10 and S20, the first hob 4 and the second hob 5 respectively cut from the two opposite end faces (the first end face and the second end face) of the plastic workpiece 100 to be machined, avoiding the problem of a large amount of burrs being formed on one end face during traditional single-tool machining, making the end face of the machined plastic gear flat and smooth, without the need for an additional deburring process, improving production efficiency and product quality. Figure 6 It is a partial schematic diagram of the machined plastic gear. As can be seen from Figure 6, the end face of the plastic gear is flat and smooth, and no burrs are observed even under a magnifying glass.
[0050] It should be noted that the first rotation direction and the second rotation direction are opposite. Specifically, the first rotation direction is the clockwise direction and the second rotation direction is the counterclockwise direction, or the first rotation direction is the counterclockwise direction and the second rotation direction is the clockwise direction. For example, during machining, if the first hob 4 rotates in the clockwise direction and enters from the first end face of the plastic workpiece 100 to be machined and cuts to the first position, during this process, the plastic workpiece 100 to be machined needs to rotate in the counterclockwise direction; while the second hob 5 needs to rotate in the counterclockwise direction, enter from the second end face of the plastic workpiece 100 to be machined and cut to the second position, and during this process, the plastic workpiece 100 to be machined needs to switch from rotating in the counterclockwise direction to rotating in the clockwise direction. Only in this way can the plastic workpiece 100 to be machined be cut, and at the same time, it can be ensured that the tooth profiles cut by the first hob 4 and the second hob 5 on the plastic workpiece 100 to be machined conform to the generation law.
[0051] In one embodiment, the second position coincides with the first position, which means that the first hob 4 and the second hob 5 complete cutting at the same axial position of the plastic workpiece 100 to be machined. In this case, the two hobs can completely machine the gear tooth profile from both ends of the workpiece, avoiding incomplete machining.
[0052] In one embodiment, the second position is located between the stroke from the first end face to the first position, that is, after the first hob 4 machines from the first end face of the plastic workpiece 100 to the first position and retracts the tool, the second hob 5 machines from the second end face of the plastic workpiece 100 to a position beyond the retraction of the tool, which can further avoid the situation of incomplete tooth profile.
[0053] In one embodiment, the front end faces of the first hob 4 and the second hob 5 are arranged opposite to each other. In this arrangement, it can be ensured that during machining, the cutting trajectories and cutting depths of the first hob 4 and the second hob 5 for the plastic workpiece 100 to be machined are more matched. At the same time, during cutting, the first hob 4 and the second hob 5 respectively cut the end faces they contact, and the cutting force directions are opposite, so that the cutting edges at both end faces can be better shaped, further effectively avoiding the generation of burrs.
[0054] Furthermore, the hob parameters of the first hob 4 and the second hob 5 are the same, and the hob parameters include modulus, pressure angle, helix angle, number of teeth, outer diameter, root diameter, and tooth thickness. Specifically, when the parameters of the first hob 4 and the second hob 5 are the same, the tooth profiles cut from both ends of the workpiece can be completely matched, and both the tooth profile contour, tooth pitch, and helix angle can be highly consistent, which can avoid the problem that one side has too large a cutting force due to the difference in hob parameters, resulting in deformation or vibration of the workpiece, and improving the machining quality.
[0055] As described above, it is only the specific implementation manners of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of various equivalent modifications or substitutions, and these modifications or substitutions should all be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims
1. A processing method for a plastic gear, characterized in that, Machining is carried out using a gear machining device, the gear machining device includes a first hob and a second hob, and the method includes: The first hob rotates in a first rotation direction and cuts into from the first end face of the plastic workpiece to be machined, and when the first hob rotates in and cuts to the first position of the plastic workpiece to be machined, stop the rotation of the first hob and retract the tool; The second hob rotates in a second rotation direction and cuts into from the second end face of the plastic workpiece to be machined, and when the second hob rotates in and cuts to the second position of the plastic workpiece to be machined, stop the rotation of the second hob and retract the tool; Wherein, the first end face and the second end face are two opposite end faces of the plastic workpiece to be machined.
2. The processing method of a plastic gear according to claim 1, characterized in that, When the first hob rotates in and cuts from the first end face of the plastic workpiece to be machined to the first position, the plastic workpiece to be machined maintains the second rotation direction.
3. A processing method of a plastic gear according to claim 2, characterized in that, When the second hob rotates in and cuts from the second end face of the plastic workpiece to be machined to the second position, the plastic workpiece to be machined maintains the first rotation direction.
4. A processing method of a plastic gear according to claim 3, characterized in that, The first rotation direction and the second rotation direction are opposite.
5. The processing method of a plastic gear according to claim 4, characterized in that The first rotation direction is the clockwise direction, the second rotation direction is the counterclockwise direction, or the first rotation direction is the counterclockwise direction, and the second rotation direction is the clockwise direction.
6. A processing method of a plastic gear according to claim 1, characterized in that, The second position coincides with the first position.
7. A processing method of a plastic gear according to claim 1, characterized in that, The second position is located between the stroke from the first end face to the first position.
8. A processing method of a plastic gear according to claim 1, characterized in that, The front end faces of the first hob and the second hob are arranged opposite to each other.
9. A processing method of a plastic gear according to claim 8, characterized in that, The hob parameters of the first hob and the second hob are the same.
10. A processing method of a plastic gear according to claim 9, characterized in that, The hob parameters include module, pressure angle, helix angle, number of teeth, outer diameter, root diameter and tooth thickness.