ZHOU Ruito，ZHENG Weigng

a．School of Energy and Power Engineering;b．Engineering Training Center，Wuhan University of Technology，Wuhan 430063，China

1.Introduction

Traditional Shaper can only do one-way planning，i．e．the returning of traditional Shaper is a kind of idle motion．This characteristic determines the low efficiency of traditional shaper machine．Although traditional Shaper has a quick return characteristic，this is not a fundamental solution to the solve low efficiency problem and make no use of the depletion problem［1］．Since there exists only one plane tool for the traditional shaper，the real cutting edge of this machine is very limited．Moreover，the machining accuracy is difficult to get improved due to the fact that the planning tends knife marks formed on the surface of the work piece［2］．Bi-planning Shaper innovative design methods are described in a lot of literature and comprehensive comparisons found that most of these designs are suitable for the production of new planer，but for present mainly used traditional Shaper transformation still exist the problems such as high cost and complex structure．This paper proposes

a simple bi-planning transformation method for the traditional Shaper，i．e．，the traditional planer structure will not be changed and the reverse plane tool will be added and controlled by electromagnet to avoid the trouble of ram constant force isokinetic mechanism design．Since the return motion of shaper is adopted，the efficiency machining accuracy of the traditional shaper will be tremendously improved．Due to the simple and reliable characteristics，a transformation experiment is conducted in this paper and the feasibility of this design has been verified based on the B6050 type of Shaper．

2.Design ideas

A reverse plane tool which is added at shaper tool holder is installed behind the forward plane tool at the same tool holder clamping shaft in the contrary．It is shifted by a certain distance in the translation direction of work piece．The pitch size is adjustable to make reverse plane tool just planning on the crest between two forward planning marks and the return motion will flatten the crest．The replacement of plane tools are controlled by the electromagnet which is installed at tool holder clamping shaft and the travel switch is used to turn on or off the current of elec-tromagnet．

3.Design and Realization of Shaper bidirectional planning

In the direction of planer forward movement，there is a certain angle of two plane tools which are installed behind the forward plane tool at the same tool holder clamping shaft．The front one is forward plane tool and the back one is reverse plane tool;In the direction of work piece plan，it is shifted by a certain distance and able to adjust the pitch size to make reverse plane tool just planning on the crest between two forward planning marks．Due to the highspeed of return motion，the machining accuracy could be improved．

The electromagnet is installed at tool holder clamping shaft and the current will be turned on or off by the travel switch．Electromagnet connects tool holder clamping shaft though a rod．Then，all the parts including two knifes，pressed blocks，turret shaft and clamping bolts are assembled at the bidirectional cutter head．When the electromagnet is not energized，the iron will not be sucked，the clamping shaft will not be raised，and the forward plane tool will be in upright position，the reverse plane tool will tilt backwards and the forward tip will be lower than the reverse one．During the forward movement，the forward plane tool will be working．When the electromagnet is energized，the iron will be sucked，the clamping shaft is lifted up，the reverse plane tool will be in the upright position，the forward plane tool is declined and the reverse’s tip is lower than the forward one．Therefore，the reverse plane tool will work during the return movement of shaper．

The control system consists of the travel switch and an AC contactor．The AC contactor is controlled by the trip switch．However，the electromagnet is controlled by the AC contactor to ensure a replacement in each planning end-of-stroke dual planer timely．

4.Specific Implementation method

In Fig．1:

1)Forward Plane Tool(8)，Reverse Plane Tool(10)，through the Tool holder clamping Shaft(2)locating hole，Tool holder clamping Shaft(2)Pass through Tool holder(11)through Hole，by Clamping Bolts(1)，Pressed Block 1(7)，Pressed Block 2(9)Fixed，forming a whole planning head．The tool holder(11)be hanged on Tool Holder Seat(12)by the pin(13)．The pin(13)One end with a cotter pin(14)．The tool holder(11)lower end of the right side against the Tool Holder Seat(12)lower end of the sudden stage，thus Forward Plane Tool(8)is the upright position，the Reverse Plane Tool(10)Right angled inclined，and the Reverse Plane Tool top higher than the Forward Plane Tool top．

2)The electromagnet(4)is installed at Frontend of Tool holder clamping Shaft(2)and is connected by the rod(5)．The electromagnet(4)is fixed on the Electromagnet holder(6)by bolts and the Electromagnet holder(6)is fixed on Tool Holder Seat(12)．

3)As shown of left view in Fig．1，twice are not on the same axis in the front and rear and are separated by an appropriate distance along the work piece translational direction．

Fig．1 Diagram of the bidirectional planning tool holder frame structure

5.Modification experiments based on the B6050 type Shaper

5.1.B6050 shaper profile

The B6050 type Shaper planning machine is a general-purpose machine which could be applied to flat，T-slot，dovetail groove．The rigidity of the machine tool is good and suitable for the batch processing parts whose length will not exceed 650 mm．The maximum length of the planning is 500 mm;The maximum distance between the ram bottom and the work piece surface is 370 mm;The maximum moving distances of workbench are as follows:horizontal distance 500 mm，vertical distance 300 mm;The maximum rotation angle of workbench is ±90°;The maximum vertical travel distance of tool holder is 110 mm;The moving frequencies of ram are as follows:15，24，37，51，64，80，102，126，158 times/min．The Ram reciprocating amount of time table feed are:the ratchet rotate a grid，vertical distance 0．0845 mm，horizontal distance 0．133 mm．

5.2.The B6050 type Shaper bidirectional planning realization

Fig．2 Modified structure show

6.The course

1)Planer start，cutter head at the starting end of the forward planning stroke，the forward plane tool will be in the upright position，forward planning will work，the pin and the tool holder seat will be lower at the end of sudden stage．When forward planer comes to the end of travel，the slider will touch front-end trip switch which is installed in slide pillow and the AC contactor will be energized，the electromagnet will be energized，the rod will be sucked up and pull up the tool holder clamping shaft，make the forward plane tool in upward tilt，the reverse plane tool will be in a vertical state planning at the return process．This is the first tool change．

2)When the reverse plane tool comes to the end of travel，AC contactor power slider touch the end of trip switch;the electromagnet will be energized and put down the rod and the tool holder clamping shaft，the reverse plane tool will restore to the state of the tilt-up，the forward plane tool will be in the upright position．This is the second tool change．

7.Conclusions

By adding reverse plane tool on traditional Shaper tool holder to realize the design of traditional Shaper bi-planning，the exchange of planers is controlled by a electromagnet．The return movement of shaper will be used and the performance efficiency of machine is improved．At the same time，the structure of machine will not be changed and the machining accuracy will be improved as well．Based on the results of this paper，a conclusion could be drawn that the design is comparatively simple and is easy to implement．This will provide some reference for the traditional Shaper bidirectional transformation．

［1］ LI SHUPING，ZHU KUIQING，CAI Chang．Mechanism Innovative Design and Reconstruction for Bi-directional Planning Shaper［J］．Submitted to Journal of Coal Mine Machinery，2008，12(29):152 －154．

［2］ WANG FENGLAN， SHA YUZHANG． Bi-planning Shaper institutions innovative design［J］．JOURNAL OF MACHINE DESIGN，2007，11(11):48－49．