This product is suitable for concrete construction of ultra-high pier and house-building structure.
Project Achievements: Chengzhong Building; Zhaolu Expressway; Tianxingzhou Bridge.
Surface Treatment: painted or as customer requirement
Application: Bridge,House-building project
Type: Hydraulic climbing Formwork
Tolerance: GB or as customer requirements
Size: Customized
MOQ: 1 set
Climbing Formwork,Steel Climbing Formwork,Concrete Climbing Formwork,Multi-Level Climbing Formwork Anshan Lijian Engineering Group Co. LTD , https://www.lijianformwork.com
Boring is the process of expanding or refining the original hole in the workpiece. It is characterized by correcting the eccentricity of the lower hole, obtaining the precise position of the hole, and achieving high precision roundness, cylindricity and surface finish. Therefore, boring processing is often used as a high-precision machining method in the final process. For example, the bearing holes of various machines and the processing of the casings and cover covers of various engines.
Boring is a difficult process compared to other machining. It only needs to adjust one blade (or blade holder) to process micron-sized holes like H7 and H6. With the popularity of the Machining Center, the current boring process requires only programming, buttoning, and the like. Because of this, there is a need for simpler, more convenient, and more sophisticated tools to ensure product quality. Here, the boring processing of the machining center is mainly analyzed from the perspective of tool technology.
2. Characteristics of the boring processing of the machining center
2.1 Tool rotation and lathe processing are different. When the machining center is machined, it is impossible to adjust the cutting edge amount in the machining process due to the rotation of the tool. It is also impossible to change the machining diameter by adjusting the CNC button just like a CNC lathe. This has become a big obstacle to fully automated processing. It is also because the machining center does not have the automatic machining diameter adjustment function (except for the U-axis function), so the boring tool must have a fine adjustment mechanism or automatic compensation function, especially in the fine boring, according to the tolerance requirements, sometimes it must be adjusted in the micrometer level. .
In addition, since the direction in which the chips flow out is constantly changing during the boring of the machining center, the cutting edge, the cooling of the workpiece, and the discharge of the chips are much more difficult than the lathe processing. Especially in the case of rough machining of steel blind holes with a vertical machining center, this problem has not been completely solved so far.
2.2 Chatter (Chatter)
The most common and most troublesome problem with boring is flutter. The main reasons for the chattering at the machining center are the following:
1 Rigidity of the tool system: including the rigidity of the shank, the mast, the hoe and the intermediate connecting portion. Because of the Stub Boring, especially the machining of small holes, deep holes and hard workpieces, the rigidity of the tool system is particularly important.
2Balance of the tool system: Compared with the rotating axis of the tool system, the tool itself has an unbalanced mass, and the fluttering occurs due to the unbalanced centrifugal force during the rotation. Especially in the high-speed machining, the dynamic balance of the tool has a great influence.
3 Clamping Rigidity of the workpiece itself or the workpiece: Like some small, thin parts, due to their own insufficient rigidity, or due to the shape of the workpiece, etc., it is not possible to use a reasonable fixture for sufficient fixing.
Geometry of Edge of the 4 blades: The cutting resistance of the blades differs depending on the rake angle, escape angle, tool nose radius, and chip breaker shape.
5Cutting Condition: Includes cutting speed, feed, feed amount, and oil supply method and type.
6 spindle system of the machine (Spindle), etc.: the rigidity of the machine spindle itself, the performance of the bearing and gear, and the rigidity of the connection between the spindle and the shank.
3, the selection criteria of the file
According to the processing content, the selection criteria of the file are different. Generally speaking, attention should be paid to the rigidity, dynamic balance, flexibility, reliability, operation convenience, life and cost of the system itself.
3.1 One-piece (Solid) boring tool and Modular boring tool The old integrated boring tool is mainly used in the production line or special machine of the quantity product, but in fact the specifications of the machine are various: NT, MT, BT, IV, CV, DV, etc. Even with the same specifications, the size is different. For example, BT has 15, 30, 40, 45, 50, 60 and so on. Even if the size and size are the same, it is possible to draw the nail shape, the thread is not the same, or the flange surface shape is different. All of these make the integrated boring tool encounter great difficulties in correspondence. Especially in recent years, the market structure and market need to be changing with each passing day, and the product cycle is shortening. This requires more flexibility and flexibility of processing machinery and processing tools. So most of the integrated boring tools have disappeared from the workshop.
The modular boring tool divides the boring tool into: Basic Holder, Extension, Reduction, Mast, Boring Head, Insert Holder, Inserts, (chamfered rings) and other parts, and then freely combined according to the specific processing content (rough, fine; hole diameter, depth, shape; workpiece material, etc.). This not only greatly reduces the number of shanks, reduces the cost, but also quickly responds to various processing requirements and extends the overall life of the tool.
The modular boring tool first appeared in the European market. About 20 years ago, Japan's Dazhao Seiki Co., Ltd. (BIG) and Swiss KAISER company cooperated technically. The BIG-KAISER modular boring tool first appeared in the Japanese market and gradually replaced it. The status of the integrated sickle. More than 80% of the machine shops in Japan today use the BIG-KAISER modular file.
It can be seen from this that the modular boring tool has the advantage that the integrated boring tool can not match. Of course, this also requires modular boring tools with high connection accuracy and high connection rigidity, as well as high repeatability and high reliability.
3.2 A variety of modular boring tools There are various modular boring systems on the market, and their connection methods are different.
1BIG-KAISER mode It only needs to be connected by a taper screw with a taper of 15°. Only one hex wrench is needed for fixing, which is very convenient to operate.
Since the screw hole and the tapered hole of the connected body have a certain eccentricity, when the screw is tightened, the majority of the tightening force is converted into the axial pulling force by the action of the tapered surface, so that the two parts to be connected are tightly attached. While maintaining the radial position unchanged.
The fixing screws are made of high shear strength material, can withstand large torques, and are reinforced when rough.
2 side solids have been seen, this connection is only for the purpose of fixing. Most of its tightening force is directed radially. Not only the end faces of the connecting body cannot be closely connected, but also the radial position changes.
3 Screw-in type Although the end faces are connected, the phase of the tool tip changes on the circumference.
4 The rear tensioning end faces are well connected and bounced, but the operability is poor.
5 other methods Side 90 ° two-point fixed way; side 180 ° two-point tilt fixed way; ABS way and so on.
All in all, the modular file system has great advantages, but it does not mean that it is just a modular one. It must be measured in terms of connection rigidity, accuracy, operability, price, and so on.
Tool Technology for Machining Center Boring
1. Introduction