Shaft sleeve gear electroplated layer finishing method

Abstract

The invention relates to a shaft sleeve gear electroplated layer finishing method, which adopts a graded electroplating process aiming at the multi-layer electroplating requirements of three areas A, B and C on the surface of a shaft sleeve gear: firstly electroplating a cadmium layer in the area A and a silver layer in the area B, and finally electroplating a thick chromium layer in the area C. And in the electroplating process of the C-region thick chromium layer, the finishing allowance is reserved, and precise grinding is carried out through a special finishing tool so as to ensure that the size and form and location tolerance of the C-region thick chromium layer meet the requirements of finished products. The finishing tool comprises a core shaft and a back cap, the sleeve shaft gear is installed on the core shaft, high-precision radial fixing and centering are achieved through conical surface fit and an elastic petal structure, and centering errors caused by threaded connection are overcome. According to the finishing method, the size control problem of the thick electroplated layer is effectively solved, the quality and the consistency of multi-plating layer surface treatment are improved, the machining defects are reduced, and the production efficiency is improved. The method is suitable for surface treatment processing of the multi-layer electroplating complex part, and has the advantages of being low in production cost, easy and convenient to operate and capable of being repeatedly used.

Description

Technical Field

[0001] The invention belongs to the technical field of metal surface treatment and relates to a method for finishing an electroplating layer of a sleeve shaft gear. Background Art

[0002] In the field of surface treatment technology, due to the complexity of product functions and the diversification of environmental requirements, higher design and quality requirements are placed on product surface treatment, which greatly increases the difficulty of process technology assurance. The requirement for single-state surface treatment (single electroplating layer) on a part has also developed into the need for multi-state surface treatment (i.e., multiple electroplating layers exist at the same time). Moreover, the complexity of product structure has also made the electroplating process more complicated, thereby increasing the difficulty of electroplating process processing.

[0003] After conventional electroplating process, if the coating is thin (≤5μm), no further processing (re-trim) is generally required, and the appearance can directly meet the requirements. However, if the coating is thick (for example, when the chromium Cr layer is 40μm or thicker), the electroplating layer cannot meet the flatness, verticality, runout and other geometric tolerance requirements required for the final use of the coating surface by direct electroplating, so it is necessary to use certain processing methods to properly trim the coating surface.

[0004] The structure of the sleeve gear is as follows Figure 1 As shown, its surface treatment technology requires three electroplating layers, mainly cadmium Cd with a thickness of 3μm on the surface of area A, silver Ag with a thickness of 3μm on the surface of area B, and chromium Cr with a thickness of 40μm on the surface of area C. The main principle of the electroplating process is to use different electroplating solutions to perform non-conductive shielding treatment in a physical isolation manner. The graded electroplating method is adopted. In the first step, the silver-plated area of ​​area B and the chromium-plated area of ​​area C are shielded with a special protective sleeve, and the cadmium-plated layer of area A is first surface treated with cadmium Cd; then silver is plated in the second step, and areas A and C are shielded with a special protective sleeve, and silver Ag is electroplated in area B; then chromium is plated in the third step, and areas A and B are shielded with a special protective sleeve, and chromium Cr is electroplated in area C. Since the electroplating layer in area C is thicker, the dimensional control accuracy is difficult to meet the technical requirements, which seriously affects the surface quality consistency and appearance requirements of the product after electroplating. Summary of the invention

[0005] In view of this, the purpose of the present invention is to solve the problem of dimensional accuracy control of thick electroplating layers and to provide a method for trimming the electroplating layer of a sleeve gear.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for finishing an electroplated layer of a sleeve gear comprises the following steps: in a process of electroplating three regions A, B and C on a sleeve gear respectively by a graded electroplating method, the thickness of the electroplated chromium in the C region is controlled to be greater than the thickness required by the finished product, leaving a finishing margin, and then the C region is precisely ground after being clamped by a finishing tool, so that the size of the electroplated layer in the C region meets the requirements of the finished product.

[0008] Further, the finishing tool comprises a mandrel and a back cap;

[0009] The sleeve gear is sleeved on the core shaft, one end of the core shaft is provided with a positioning section, the positioning section cooperates with the inner hole of the sleeve gear to provide radial positioning support for the sleeve gear, and the other end of the core shaft is provided with a conical section;

[0010] The back cap is provided with a tapered hole, and is sleeved on the conical section through the tapered hole, and forms a conical surface fit with the core shaft; the outer circle of the back cap is provided with a thread, and is threadedly connected with the inner hole of the sleeve gear through the thread;

[0011] The tapered hole is provided with slots evenly distributed around the circumference, and the threads on the outer circle of the back cap are connected with the tapered hole to form multiple elastic petals; when the back cap is threadedly connected with the sleeve shaft gear, the back cap moves under the drive of the threads, and after the conical section of the mandrel fits with the tapered hole, the elastic petals expand radially under the extrusion of the conical surface, thereby radially tightening and fixing the sleeve shaft gear. At the same time, the back cap is centered by the tapered surface, overcoming the problem of poor centering of the threaded connection.

[0012] Furthermore, the core shaft passes through the back cap, and both ends of the core shaft are provided with center holes.

[0013] Furthermore, a positioning shoulder is provided on one side of the positioning section of the core shaft, and the sleeve gear is axially limited by the positioning shoulder.

[0014] Furthermore, the positioning section of the core shaft and the inner hole of the sleeve gear are matched with H7 / j6.

[0015] Furthermore, the cone angle of the cone surface where the core shaft and the back cap fit together is 60°.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention adopts a strategy of leaving a trimming margin for thick electroplating layers, thereby avoiding over-reliance on precise control of electroplating thickness during the electroplating process. Especially for the case where the chromium plating layer in the C area is thicker, the method ensures that the thickness and shape and position tolerance of the electroplating layer meet the technical requirements through a subsequent precision grinding process, reduces rework and scrap rate caused by dimensional tolerance, and ensures production consistency.

[0018] 2. The present invention can avoid surface defects caused by deformation of thick coating or uneven electroplating, ensuring that the flatness, verticality and runout of the final product meet the tolerance requirements. The functionality and durability of the sleeve gear during use are guaranteed, so that it can meet the accuracy and stability requirements in various working environments.

[0019] 3. The present invention adopts standardized finishing tools for clamping and grinding, avoiding complicated manual adjustment steps and improving processing efficiency. The finishing tools such as mandrel and back cap are reasonably designed, simple to operate, and quickly positioned and fixed, which greatly shortens the clamping and processing time, thereby speeding up the overall production cycle.

[0020] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0022] Figure 1 It is a schematic diagram of the structure of the sleeve gear in the present invention.

[0023] Figure 2 It is an overall schematic diagram of the trimming tool in the present invention.

[0024] Figure 3 Schematic diagram of the back cap structure.

[0025] Figure numerals: 1- spindle; 2- back cap; 3- sleeve shaft gear. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0027] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0028] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which 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 operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0029] See also Figures 1 to 3 , which is a method for finishing the electroplating layer of a sleeve gear. In the process of electroplating the three areas A, B, and C on the sleeve gear 3 by using a graded electroplating method, the specific electroplating process adopts the electroplating method in CN117552064A, and the thickness of the electroplated chromium in the C area is controlled to be greater than the thickness required by the finished product, leaving a finishing margin, and then the C area is precisely ground after being clamped by a finishing tool, so that the size of the electroplated layer in the C area meets the requirements of the finished product.

[0030] The finishing tooling includes a core shaft 1 and a back cap 2; the sleeve gear 3 is sleeved on the core shaft 1, and a positioning section is provided at one end of the core shaft 1, and the positioning section cooperates with the Φ98H7 inner hole at the left end of the sleeve gear 3 to radially position and support the sleeve gear 3, and a conical section is provided at the other end of the core shaft 1; a conical hole is provided in the back cap 2, and it is sleeved on the conical section through the conical hole, and a conical surface fits with the core shaft 1; a thread is provided on the outer circle of the back cap 2, and the thread is connected with the inner hole thread of the sleeve gear 3 through the thread using M105×1.5-6H / 6g; the conical hole is provided with circumferentially evenly distributed grooves, and the thread on the outer circle of the back cap 2 is connected with the conical hole to form a plurality of elastic petals; when the back cap 2 is threadedly connected with the sleeve gear 3, the back cap 2 moves driven by the thread, and after the conical section of the core shaft 1 fits with the conical hole, the elastic petals are radially expanded under the extrusion of the conical surface, thereby radially tightening and fixing the sleeve gear 3. At the same time, the back cap 2 is centered by the conical surface cooperation, so as to overcome the problem of poor centering of the threaded connection.

[0031] The mandrel 1 passes through the back cap 2, and both ends of the mandrel 1 are provided with a center hole. The positioning section of the mandrel 1 and the inner hole of the sleeve gear 3 are matched with Φ98H7 / j6. The cone angle of the cone surface where the mandrel 1 and the back cap 2 fit is 60°.

[0032] A positioning shoulder is provided on one side of the positioning section of the core shaft 1 , and the sleeve gear 3 is axially limited by the positioning shoulder.

[0033] The method in this embodiment is used to trim and grind the outer circle and end face of the electroplated chrome Φ124, and the grinding outer circle and end face runout is ≤0.005mm, achieving a good precision control effect, which is far lower than the finished product runout requirement of ≤0.030mm.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A method for finishing the electroplating layer of a sleeve gear, characterized in that: In the process of electroplating the three areas A, B, and C on the sleeve gear by graded electroplating, the thickness of the electroplated chromium in area C is controlled to be greater than the thickness required for the finished product, leaving a trimming margin. After being clamped by a trimming tool, area C is precision ground so that the size of the electroplated layer in area C meets the requirements of the finished product.

2. The method for finishing the electroplating layer of a sleeve gear according to claim 1, characterized in that: The finishing tool comprises a mandrel and a back cap; The sleeve gear is sleeved on the core shaft, one end of the core shaft is provided with a positioning section, the positioning section cooperates with the inner hole of the sleeve gear to provide radial positioning support for the sleeve gear, and the other end of the core shaft is provided with a conical section; The back cap is provided with a tapered hole, and is sleeved on the conical section through the tapered hole, and forms a conical surface fit with the core shaft; the outer circle of the back cap is provided with a thread, and is threadedly connected with the inner hole of the sleeve gear through the thread; The tapered hole is provided with grooves evenly distributed around the circumference, and the threads on the outer circle of the back cap are connected with the tapered hole to form a plurality of elastic petals. When the back cap is threadedly connected with the sleeve gear, the back cap moves driven by the threads, and after the conical section of the core shaft fits with the tapered hole, the elastic petals expand radially under the extrusion of the conical surface, thereby radially tightening and fixing the sleeve gear.

3. The method for finishing the electroplating layer of a sleeve gear according to claim 2, characterized in that: The core shaft passes through the back cap, and both ends of the core shaft are provided with central holes.

4. The method for finishing the electroplating layer of a sleeve gear according to claim 2, characterized in that: A positioning shoulder is provided on one side of the positioning section of the core shaft, and the sleeve shaft gear is axially limited by the positioning shoulder.

5. The method for finishing the electroplating layer of a sleeve gear according to claim 2, characterized in that: The positioning section of the core shaft and the inner hole of the sleeve gear are matched with H7 / j6.

6. The method for finishing the electroplating layer of a sleeve gear according to claim 2, characterized in that: The cone angle of the cone surface where the core shaft and the back cap fit together is 60°.

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