Electrode device for preventing eccentricity and chamfering of a taper nozzle hole in EDM machining
Patent Information
- Application Number
- CN202521823414.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-26
- Publication Date
- 2026-09-22
- Estimated Expiration
- 2035-08-26
AI Technical Summary
[0003]因为孔深导致的电极加长装夹结构，在EDM加工过程中易受振动和装夹力影响发生径向偏移，粗加工与精加工电极的定位基准难以重合，导致孔位偏心误差，电极稳定性不足；且常规电极缺乏精确导向设计，精加工电极与工件接触面无渐进式定位结构，放电过程中电极微偏移使孔口区域放电能量分布不均，形成圆角，进而产生口部披峰，破坏封胶面平整度，为消除圆角缺陷，需对工件进行手工修磨或重挖镶件处理，单件修整工时增加，且镶件报废率提高，显著推升制造成本
[0011]1、本实用新型提供一种斜热嘴孔EDM加工防偏心及口部圆角的电极装置，通过阶梯式电极机构与双层绝缘导向机构的双重定位配合，斜孔偏心误差控制在±0.01mm以内，提高合格率，彻底解决粗/精加工基准不重合问题，消除加工偏心误差。
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Figure CN224779529U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of precision electrical discharge machining technology, specifically to an electrode device for preventing eccentricity and rounding the opening corners in EDM machining of oblique hot nozzle holes. Background Technology
[0002] In the manufacturing of automotive molds and large, complex injection molding structures, the machining accuracy of the angled hot runner hole directly affects the sealing performance and appearance quality of the injection molded product. Traditional electrical discharge machining (EDM) for angled hot runner holes requires the use of extended electrodes to meet deep hole machining requirements. The existing technology suffers from the following problems:
[0003] The electrode lengthening clamping structure due to the hole depth is susceptible to radial displacement caused by vibration and clamping force during EDM processing. The positioning reference of the roughing and finishing electrodes is difficult to coincide, resulting in hole position eccentricity error and insufficient electrode stability. In addition, conventional electrodes lack precise guiding design, and the contact surface between the finishing electrode and the workpiece lacks a progressive positioning structure. During the discharge process, the slight displacement of the electrode causes uneven distribution of discharge energy in the hole area, forming rounded corners, which in turn produces burrs at the opening, damaging the flatness of the sealing surface. To eliminate the rounded corner defects, the workpiece needs to be manually ground or re-carved for inserts, which increases the processing time per piece and the scrap rate of inserts, significantly increasing manufacturing costs. Utility Model Content
[0004] This invention provides an electrode device for preventing eccentricity and rounding the opening corners in EDM machining of oblique hot nozzle holes, in order to solve the problems mentioned in the background art.
[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:
[0006] An electrode device for anti-eccentricity and rounded corners in EDM machining of oblique hot nozzle holes includes a stepped electrode mechanism. The stepped electrode mechanism has an electrode clamping end at its rear end, and a double-layer insulating guide mechanism at its rear end. The stepped electrode mechanism includes an electrode working section, and an axially extending electrode guide section is fixedly installed at the front end of the electrode working section. The electrode guide section has a length of 5mm and a single-sided radial dimension 0.05mm smaller than that of the electrode working section. The electrode working section is fixedly installed at the front end of the electrode clamping end. The double-layer insulating guide mechanism includes an adjustable positioning pin, which is fixedly installed on the rear side of the electrode clamping end. An elastic insulating layer is fixedly sleeved on the outer wall of the adjustable positioning pin, and a rigid metal sleeve is fixedly sleeved on the outer wall of the elastic insulating layer.
[0007] A further improvement of this utility model is that the diameter of the electrode guide section is 0.02 mm smaller than the target aperture, and the spark position of the electrode working section is designed to be -0.10 mm.
[0008] A further improvement of this utility model is that the adjustable positioning pin has a clearance fit with the workpiece reference hole, and the fit tolerance is H7 / g6.
[0009] A further improvement of this utility model is that the elastic insulating layer is made of polytetrafluoroethylene material with a thickness of 0.5-1mm.
[0010] Due to the adoption of the above technical solution, the technological progress achieved by this utility model compared to the prior art is as follows:
[0011] 1. This utility model provides an electrode device for preventing eccentricity and rounding the opening corners in EDM machining of oblique hot nozzle holes. Through the dual positioning cooperation of the stepped electrode mechanism and the double-layer insulation guide mechanism, the eccentricity error of the oblique hole is controlled within ±0.01mm, improving the pass rate, completely solving the problem of non-coincidence of rough / fine machining datum, and eliminating machining eccentricity error.
[0012] 2. This utility model provides an electrode device for anti-eccentricity and rounded corners in EDM machining of inclined hot nozzle holes. The electrode guide section stably guides the electrode working section to feed along the same path, avoiding radial movement. The electrode working section is finely finished with a spark position of -0.10mm and low energy parameters to make the discharge at the opening uniform. The double-layer insulation guide mechanism further suppresses vibration, ensures the consistency of the gap between the electrode and the hole wall, and makes the sealing surface flat without peaks. It eliminates the need for manual grinding or re-digging of inserts, thus reducing costs. Attached Figure Description
[0013] Figure 1 This is a schematic diagram of the overall structure of this utility model;
[0014] Figure 2 This is a schematic diagram of the stepped electrode mechanism of this utility model.
[0015] Figure 3 This is a schematic diagram of the double-layer insulated guide mechanism of this utility model.
[0016] In the figure: 1. Stepped electrode mechanism; 11. Electrode working section; 12. Electrode guide section; 2. Electrode clamping end; 3. Double-layer insulated guide mechanism; 31. Adjustable positioning pin; 32. Elastic insulation layer; 33. Rigid metal sleeve. Detailed Implementation
[0017] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.
[0018] like Figure 1-3As shown, this utility model provides an electrode device for anti-eccentricity and rounded corners in EDM machining of inclined hot nozzle holes. It includes a stepped electrode mechanism 1, an electrode clamping end 2 at the rear end of the stepped electrode mechanism 1, a double-layer insulating guide mechanism 3 at the rear end of the electrode clamping end 2, an electrode working section 11, an axially extending electrode guide section 12 fixedly installed at the front end of the electrode working section 11, the electrode guide section 12 is 5mm long and its radial dimension on one side is 0.05mm smaller than that of the electrode working section 11, the electrode working section 11 is fixedly installed at the front end of the electrode clamping end 2, the diameter of the electrode guide section 12 is 0.02mm smaller than the target hole diameter, and the spark position of the electrode working section 11 is designed to be -0.10mm.
[0019] The electrode guide section 12 forms the initial hole wall with a small gap discharge, which constrains the radial movement of the subsequent electrode working section 11. The electrode working section 11 adopts low-energy fine finishing to make the discharge in the mouth area uniform and avoid the rounded corner defects caused by electrode vibration in traditional processing. In the roughing stage: the roughing spark position is -0.35mm, with a high current of 30A and a pulse width of 250μs to quickly remove material; in the finishing stage: the fine spark position is -0.10mm, with a low current of 8A and a pulse width of 60μs, which, together with the electrode stepped structure, achieves a smooth mouth.
[0020] like Figure 1-3 As shown, the double-layer insulated guide mechanism 3 includes an adjustable positioning pin 31, which is fixedly installed on the rear side of the electrode clamping end 2. An elastic insulating layer 32 is fixedly sleeved on the outer wall of the adjustable positioning pin 31, and a rigid metal sleeve 33 is fixedly sleeved on the outer wall of the elastic insulating layer 32. The adjustable positioning pin 31 is clearance-fitted with the workpiece reference hole, and the fit tolerance is H7 / g6. The elastic insulating layer 32 is made of polytetrafluoroethylene material with a thickness of 0.5-1mm.
[0021] The adjustable positioning pin 31 cooperates with the reference hole to eliminate macroscopic offset, and the polytetrafluoroethylene insulation layer used in the elastic insulation layer 32 can absorb EDM high-frequency vibration.
[0022] The working principle of the electrode device for anti-eccentricity and rounded corners in EDM machining of the inclined hot nozzle is explained in detail below.
[0023] like Figure 1-3 As shown, the diameter of the electrode guide section 12 at the front end of the electrode is 0.02 mm smaller than the target hole diameter. First, a small gap discharge is used to form an initial hole wall on the workpiece and establish a precise positioning channel. The electrode working section 11 with a spark position of -0.10 mm enters along the channel formed by the guide section for low-energy fine finishing to avoid radial movement and ensure uniform discharge at the opening. The double-layer insulating guide mechanism 3 at the rear end eliminates macroscopic offset by matching the gap between the adjustable positioning pin 31 and the workpiece reference hole. The elastic insulating layer 32 absorbs EDM high-frequency vibration and improves stability.
[0024] The present invention has been described in detail above. However, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, any modifications or improvements that do not depart from the spirit of the present invention are within the protection scope of the present invention.
Claims
1. An electrode device for preventing eccentricity and rounding the mouth corner in EDM machining of a slanted hot nozzle, comprising a stepped electrode mechanism (1), characterized in that: The stepped electrode mechanism (1) is provided with an electrode clamping end (2) at its rear end. The electrode clamping end (2) is provided with a double-layer insulating guide mechanism (3) at its rear end. The stepped electrode mechanism (1) includes an electrode working section (11). An axially extending electrode guide section (12) is fixedly installed at the front end of the electrode working section (11). The electrode guide section (12) is 5 mm long and its radial dimension on one side is 0.05 mm smaller than that of the electrode working section (11). The electrode working section (11) is fixedly installed at the front end of the electrode clamping end (2). The double-layer insulating guide mechanism (3) includes an adjustable positioning pin (31). The adjustable positioning pin (31) is fixedly installed on the rear side of the electrode clamping end (2). An elastic insulating layer (32) is fixedly sleeved on the outer wall of the adjustable positioning pin (31). A rigid metal sleeve (33) is fixedly sleeved on the outer wall of the elastic insulating layer (32).
2. The electrode device for anti-eccentricity and rounded corners in EDM machining of oblique hot nozzle holes according to claim 1, characterized in that: The diameter of the electrode guide section (12) is 0.02 mm smaller than the target aperture, and the spark position of the electrode working section (11) is designed to be -0.10 mm.
3. The electrode device for anti-eccentricity and rounded corners in EDM machining of oblique hot nozzle holes according to claim 1, characterized in that: The adjustable positioning pin (31) is clearance-fitted with the workpiece reference hole, with a fit tolerance of H7 / g6.
4. The electrode device for anti-eccentricity and rounded corners in EDM machining of oblique hot nozzle holes according to claim 1, characterized in that: The elastic insulating layer (32) is made of polytetrafluoroethylene and has a thickness of 0.5-1 mm.