Machining process for end face teeth of bell housing of universal coupling

Abstract

A machining technology for end face teeth of a universal coupling bell housing comprises the following steps that firstly, deep carburizing treatment is conducted on the bell housing, specifically, the bell housing is provided, and deep carburizing treatment is conducted on the whole bell housing, so that a carburizing layer is formed on the surface of the bell housing; the depth of the carburized layer extending from the surface of the bell housing to the inside is 1.2-1.8 cm; and 2, turning and removing a hard layer at the machining end: clamping the bell-shaped shell subjected to deep carburizing treatment on a lathe, turning the end to be machined of the bell-shaped shell, turning and removing a carburized layer in the area, exposing a softened base material layer below, and simultaneously machining a plurality of convex blocks for later machining of a tooth groove. According to the machining technology for the end face teeth of the bell housing of the universal coupling, the deep hardening effect can be achieved, and the high precision of the end face teeth can be guaranteed.

Description

Technical Field

[0001] This invention relates to the field of universal coupling manufacturing technology, and in particular to a machining process for the end face teeth of a bell-shaped universal coupling. Background Technology

[0002] The bell-shaped housing is the core force transmission component of the universal coupling. The machining accuracy and strength of its end face teeth directly determine the transmission efficiency and service life of the coupling. The end face teeth need to have extremely high surface hardness and a sufficiently deep carburized layer. However, there is an irreconcilable contradiction between the existence of the carburized layer and the machining of the precision tooth shape.

[0003] If a tooth groove about 5mm deep is first drawn into a soft bell-shaped shell, and then deep carburizing and quenching are performed, the uneven depth and wall thickness of the tooth groove will cause the heat treatment phase transformation stress to cause the tooth groove to twist and the tooth pitch to change, making it impossible to guarantee accuracy.

[0004] If the bell-shaped shell is first subjected to deep carburizing and quenching to obtain a high-hardness carburized layer, and then broaching is attempted, the surface hardness of the carburized layer is extremely high and the depth is relatively deep. Direct broaching will cause the broach to wear rapidly, and in severe cases, even chip. Not only is the processing cost extremely high, but the tooth surface is also prone to micro-cracks. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a machining process for the end face teeth of the bell-shaped shell of a universal coupling, which can not only achieve a deep hardening effect, but also ensure the high precision of the end face teeth.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] This invention discloses a machining process for the end face teeth of a bell-shaped shell of a universal coupling, comprising the following steps: Step 1, deep carburizing treatment of the bell-shaped shell: After rough machining of the bell-shaped shell, deep carburizing treatment is performed to form a carburized layer on the surface of the bell-shaped shell; the depth of the carburized layer extending from the surface of the bell-shaped shell inward is 1.2cm to 1.8cm; Step 2, turning removal of the hardened layer at the machining end: The bell-shaped shell after deep carburizing treatment is clamped on a lathe, and the end of the bell-shaped shell to be machined is turned to remove the carburized layer in this area, exposing the softened substrate layer underneath, and at the same time, several protrusions are machined for subsequent machining of the tooth groove; Step 3, overall quenching treatment: The turned end of the bell-shaped shell is then quenched. After removing the hardened layer, the bell-shaped shell undergoes overall quenching treatment, transforming the carburized layer in the unmachined area into a high-hardness martensite structure. Simultaneously, the softened substrate layer and bumps exposed after machining achieve the required matrix strength. Step four, precision broaching of the guide groove: Using a first broach, a precision guide groove of depth H1 is broached along the final extension direction of the tooth groove on the softened substrate layer of the bump after step three. H1 is 0.05mm to 0.15mm. Step five, final tooth groove forming broaching: Using a second broach, with the precision guide groove broached in step four as a guide and chip space, an end face tooth groove of final depth H2 is broached. H2 is 5mm.

[0008] H1 is 0.1 mm.

[0009] H2 is greater than 10 times H1.

[0010] The tooth profiles of the first broach and the second broach are uniformly reduced by 0.01-0.03 mm in the tooth width direction, so that the width of the guide groove is smaller than the final tooth groove width, thereby enabling the two sides of the second broach to achieve balanced precision cutting during broaching in step five.

[0011] After completing step five, a coordinate measuring machine is used to check the tooth pitch, tooth profile, and runout accuracy of the end face teeth. Minor grinding corrections are performed on the out-of-tolerance areas to ensure that the accuracy meets the design requirements.

[0012] The number of protrusions is four, forming a first protrusion, a second protrusion, a third protrusion, and a fourth protrusion; the first protrusion and the second protrusion are symmetrically distributed on the end face of the bell-shaped shell; the third protrusion and the fourth protrusion are symmetrically distributed on the end face of the bell-shaped shell; the line connecting the first protrusion and the second protrusion and the line connecting the third protrusion and the fourth protrusion form a 70-degree angle.

[0013] The present invention has the following beneficial effects:

[0014] Compared with existing technologies, the processing technology of the universal coupling bell-shaped shell end face teeth using the process of this invention can be achieved by first deep carburizing to form a carburized layer, then turning to remove the hardened layer at the machined end, followed by quenching, and finally step-by-step broaching. This process ensures that the non-machined areas of the bell-shaped shell can obtain a deep hardened layer with a depth of 1.2-1.8cm, meeting the requirements for heavy-duty wear resistance. At the same time, by partially removing the hardened layer at the machined end, softening and machinable conditions are created for subsequent precision broaching, effectively avoiding the situation where the machined surface is too hard to machine. Furthermore, the heat treatment processes of deep carburizing and quenching, which may cause large deformations, are all completed before broaching the tooth groove, thus ensuring that the subsequent broaching is carried out on a stabilized substrate, no longer subject to stress interference, effectively guaranteeing the tooth profile accuracy and positional accuracy of the end face teeth. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the bell-shaped housing of a universal coupling;

[0016] Figure 2 This is a cross-sectional view of the bell-shaped housing of the universal coupling. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0018] Please see Figure 1 , Figure 2 This invention provides a machining process for the end face teeth of a bell-shaped housing of a universal coupling, comprising the following steps: Step 1, deep carburizing treatment of the bell-shaped housing: After rough machining of the bell-shaped housing 7, deep carburizing treatment is performed to form a carburized layer on the surface of the bell-shaped housing; the depth of the carburized layer extending from the surface of the bell-shaped housing to the interior is 1.2cm to 1.8cm; Step 2, turning removal of the hardened layer at the machining end: The bell-shaped housing after deep carburizing treatment is clamped on a lathe, and the end of the bell-shaped housing to be machined is turned to remove the carburized layer in this area, exposing the softened substrate layer underneath, and at the same time, several protrusions are machined for subsequent machining of the tooth groove; Step 3, overall quenching treatment: The turned end of the bell-shaped housing is then quenched. After removing the hardened layer, the bell-shaped shell undergoes overall quenching treatment, transforming the carburized layer in the unmachined area into a high-hardness martensite structure. Simultaneously, the softened substrate layer and protrusions exposed after machining achieve the required matrix strength. Step four, precision broaching of the guide groove: Using a first broach, a precision guide groove of depth H1 is broached along the final extension direction of the tooth groove on the softened substrate layer of the protrusion after step three. H1 is 0.05mm to 0.15mm. Step five, final tooth groove forming broaching: Using a second broach, with the precision guide groove broached in step four as a guide and chip space, an end face tooth groove 8 with a final depth H2 is broached. H2 is 5mm.

[0019] Therefore, this invention can be understood as follows: by first forming a carburized layer through deep carburizing, then removing the hardened layer at the machined end by turning, followed by quenching, and finally step-by-step broaching, the non-machined areas of the bell-shaped shell can obtain a deep hardened layer with a depth of 1.2-1.8cm, meeting the requirements for heavy-duty wear resistance. At the same time, by partially removing the hardened layer at the machined end, softening and machinable conditions are created for subsequent precision broaching, effectively avoiding the situation where the machined surface is too hard to machine. Moreover, the heat treatment processes of deep carburizing and quenching, which may cause large deformations, are all completed before broaching the tooth grooves, thus ensuring that the subsequent broaching is carried out on a stabilized substrate, no longer subject to stress interference, effectively ensuring the tooth profile accuracy and positional accuracy of the end face teeth. The ordinary turning method can economically and efficiently remove the carburized layer in the machined area, which is simple to operate and cost-controllable. After turning, the machined area exposes the softened substrate layer. After quenching, it can not only obtain the appropriate hardness for broaching but also maintain good toughness. At this time, the non-machined area can retain the high hardness of the carburized layer, thus ensuring that the hardness of each part of the bell-shaped shell meets the actual requirements.

[0020] The H1 is 0.1 mm, which is deep enough to provide stable guidance for subsequent broaching up to 5 mm deep, effectively resisting the lateral force of broaching. At the same time, its depth is shallow enough to minimize the heat and stress generated by broaching, further avoiding the introduction of additional deformation or damage risks before precision forming, and ensuring the stability and repeatability of the process.

[0021] The fact that H2 is greater than 10 times H1 can clearly define the ratio between the guide groove and the final tooth groove, thereby accurately realizing the machining method of guiding an extremely deep tooth groove through an extremely shallow guide groove.

[0022] The tooth profiles of the first broach and the second broach are uniformly reduced by 0.01-0.03 mm in the tooth width direction, so that the width of the guide groove is smaller than the final tooth groove width. Thus, during broaching in step five, the two cutting edges of the second broach can achieve balanced precision cutting, significantly improving the tooth surface quality, tooth profile symmetry and dimensional consistency, and avoiding tool deviation or tooth profile error that may be caused by uneven cutting force on one side.

[0023] After completing step five, a coordinate measuring machine is used to check the pitch, tooth profile, and runout accuracy of the end face teeth. Minor grinding corrections are performed on out-of-tolerance areas to ensure that the accuracy meets the design requirements. At the same time, the broaching process parameters can be continuously monitored and optimized through feedback data, thereby systematically ensuring the consistency between product batches.

[0024] The number of protrusions is four, forming a first protrusion 1, a second protrusion 2, a third protrusion 3, and a fourth protrusion 4. The first protrusion 1 and the second protrusion 2 are symmetrically distributed on the end face of the bell-shaped shell 7. The third protrusion 3 and the fourth protrusion 4 are symmetrically distributed on the end face of the bell-shaped shell 7. The line 5 connecting the first protrusion 1 and the second protrusion 2 and the line 6 connecting the third protrusion 3 and the fourth protrusion 4 form a 70-degree angle. Compared with the common 90-degree orthogonal or equal distribution, the 70-degree angle can better balance and decompose the radial component force and overturning moment generated during the transmission process, thereby reducing stress concentration, improving the overall load-bearing capacity and fatigue life. At the same time, the asymmetrical 70-degree distribution can form a staggered interlocking effect during the transmission process. When the first protrusion 1 and the second protrusion 2 bear the main load, the third protrusion 3 and the fourth protrusion 4 can provide effective lateral support, suppress possible circumferential fretting or vibration, and enhance the overall rigidity and impact resistance of the meshing pair.

Claims

1. A machining process for the end face teeth of a bell-shaped housing of a universal coupling, characterized in that, Includes the following steps: Step 1, Deep carburizing treatment of bell-shaped shell: After the rough machining of bell-shaped shell is completed, deep carburizing treatment is performed to form a carburized layer on the surface of bell-shaped shell; the depth of the carburized layer extending from the surface of bell-shaped shell to the interior is 1.2cm to 1.8cm. Step 2, machining the hard layer at the machining end: The bell-shaped shell that has undergone deep carburizing treatment is clamped on a lathe, and the end of the bell-shaped shell to be machined is machined to remove the carburized layer in this area, exposing the softened substrate layer underneath. At the same time, several protrusions are machined for later machining of the tooth groove. Step 3, overall quenching treatment: The bell-shaped shell after the hard layer is removed by turning is subjected to overall quenching treatment, so that the carburized layer in the unturned area is transformed into a high-hardness martensite structure, and at the same time, the softened base material layer and bumps exposed after turning reach the required matrix strength. Step 4, Precision broaching of the guide groove: Using the first broach, a precision guide groove of depth H1 is broached along the final extension direction of the tooth groove on the bump softened substrate layer after step 3; H1 is 0.05mm to 0.15mm; Step 5, final tooth groove forming broaching: Using the second broach, with the precision guide groove broached in step 4 as the guide and chip space, broach the end face tooth groove with a final depth of H2; where H2 is 5mm.

2. The machining process of the bell-shaped shell end face teeth of a universal coupling according to claim 1, characterized in that: H1 is 0.1 mm.

3. The machining process for the end face teeth of the bell-shaped shell of a universal coupling according to claim 1, characterized in that: H2 is greater than 10 times H1.

4. The machining process for the end face teeth of the bell-shaped shell of a universal coupling according to claim 1, characterized in that: The tooth profiles of the first broach and the second broach are uniformly reduced by 0.01-0.03 mm in the tooth width direction, so that the width of the guide groove is smaller than the final tooth groove width, thereby enabling the two sides of the second broach to achieve balanced precision cutting during broaching in step five.

5. The machining process for the end face teeth of the bell-shaped shell of a universal coupling according to claim 1, characterized in that: After completing step five, a coordinate measuring machine is used to check the tooth pitch, tooth profile, and runout accuracy of the end face teeth. Minor grinding corrections are performed on the out-of-tolerance areas to ensure that the accuracy meets the design requirements.

6. The machining process for the end face teeth of the bell-shaped shell of a universal coupling according to claim 1, characterized in that: The number of protrusions is four, forming a first protrusion, a second protrusion, a third protrusion, and a fourth protrusion; the first protrusion and the second protrusion are symmetrically distributed on the end face of the bell-shaped shell; the third protrusion and the fourth protrusion are symmetrically distributed on the end face of the bell-shaped shell; the line connecting the first protrusion and the second protrusion and the line connecting the third protrusion and the fourth protrusion form a 70-degree angle.

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