Process design analysis of shaft parts

Analysis of parts drawings

By the cylindrical surface of the member, so straight arc, anti-bow, conical, recessed, screw holes and so on. Dimension setting is complete. The billet is 45 # steel Φ50mm × 120mm. Heat treatment: Modulation, HRC25-35 has no hardness requirements.

Determine the processing method

The principle of selecting a processing method is to ensure the processing accuracy and surface roughness of the processed surface.

Since there are many ways to obtain the same level of machining accuracy and surface roughness, it is necessary to consider the shape, dimensions, and part tolerances such as shape and position of other factors in the actual selection. I have. In this figure, some precision requires a larger size. Because the tolerance values ​​are small, the average is not used during programming, its base size is used. It has a taper of 5 and an arc cut: 1 contour, which requires the coordinates (29.7,0) (34,16.5) (46,22.5) during programming.

Based on the above data analysis, the most ideal processing method is steering, considering processing efficiency and economical processing. Considering that parts are processed in batches, the processing equipment uses CNC lathes. CJK6032 Cnc Machine tools are selected according to the shape and material conditions of the machined parts.

Determine a treatment plan

More precise machining of the part surface is usually achieved by roughing, semi-finishing and finishing. Choosing the right final treatment for these surfaces based solely on quality requirements is not enough. The machining plan from blank to final molding should also be determined appropriately.

The blank first holds the right edge and rotates the left edge of the contour. 50mm, left side processing Φ46mm, Φ29.7mm, gradient 1: 5 gradient, R6 radian, Φ20mm hole, Φ20mm hole, C1.5 chamfer.

The title clamp is processed with an outer ring of Φ46 mm, and the right end is processed with Φ36 mm, cutting sipe, M27 × 1.5, Φ20 mm, SΦ20 mm processed thread, and the size is smaller.

A typical axis processing sequence is Preparation –Turning surface –Left end contour processing –Finishing Left end contour processing –Excavation –Roughing –Fine boring –Work U-turn –Roughing Right end contour –Right end contour finishing –Cutting groove processing –Rough thread cutting screw –Turning the screw Finish.

Determine positioning criteria and installation method

• (1) Positioning origin: Determines the blank axis and outer circular surface that serve as the reference for positioning.
• (2) Clamping method: Clamps the centering using a 3-jaw self-centering chuck.

Determine the processing order and feed route

The order of processing is determined from coarse to fine and close to distant.

That is, from right to left, vandalize the car (leaving a 0.25mm rotating edge),

Then complete the right-to-left rotation and finally the thread.

Tool selection

• (1) Drill the center hole using a Φ5mm center drill.
• (2) Use a Φ20mm high-speed steel twist drill.
• (3) A 90 ° carbide turning tool is used for rough turning and flat end faces.
• (4) Use a cutter with a width of 5 mm.
• (5) The thread is made with a cemented carbide 60 ° male thread machining tool. The radius of the tool tip radius is less than the minimum arc radius of 0.15-0.2 mm. The selected tool parameters are entered into the NC machining card (see table) for easy programming and operation management.

Selection of cutting amount

• (1) Returning to the selection of knives, the selection of rough turning cycle is 3 mm, finish turning is 0.25 mm, screw rough turning is 0.4 mm, tool is reduced, and finish is 0.1 mm.
• (2) Spindle speed selection, straight rotation and arc, selective rough turning cutting speed 90m / min, finishing turning speed 120m / min,
  Then use the formula to calculate the spindle speed. Coarse rotation, 500r / min, Finishing: 1200 rotations / minute
• (3) When the feed rate is selected, the lookup table selects coarse rotation, and the rotation feed is completed every time. Then, the actual determination method of the rough turning per rotation is 0.4 mm / R, the end of the rotation per rotation is 0.15 mm / R, and finally the rough turning is calculated by the following formula. Finish feed rates are 200 mm / min and 180 mm / min, respectively.

Completely analyze the various contents of the previous analysis and fill out the NC process card. It represents the main basis for preparation for NC machining and preparation of guidance documents by operators.

The main contents include the order of work steps, the contents of work steps, the cutting tool, and the cutting amount used in each work step.

Manual programming of shaft components

Leftmost handler:
O0020 Program number
N001 G21 G99 G97 G40; Initialization procedure
N002 M03 S500 T0303; Spindle rotation, speed 500,3 knife, tool compensation
N003 G00 X52 Z2; High-speed positioning cycle start (52,2)
N004 G71 U1.0 R0.5; Overview
N005 G71 P006 Q010U0.3 W0.1 F0.15; Rough lathe, 0.3 mm margin in X direction, 0.1 mm margin in Z direction
N006 G01 X29.7 Z0; Straight road (29.7,0)
N007 X40 Z-16.5; Straight (40, -16.5)
N008 G02 U6 W-6 R6; Turn clockwise (46 ° -22.5) with a radius of R6 mm
N009 G01 Z-50, from a straight line (46, -50)
N010 U2; From a straight line (48,16.5)
N011 G00 X31 Z2; Fast positioning to the start of the cycle
N012 G70 P006 Q010 F0.15; Complete the outer contour
N013 G00 X100 Z50; Retreat to Tool Change Point
N014 MO3; Spindle steady state
N015 M05; The program has stopped

After turning the right side of the handler:
O0021 Program number
N001 G21 G99 G97 G40; Initialization procedure
N002 M03 S500 T0303; Spindle rotation, speed 500,3 knife, tool compensation
N003 G00 X52 Z2; Quick positioning cycle start (52,2)
N004 G71 U1.0 R0.5; Overview
N005 G71 P006 Q018U0.3 W0.1 F0.15; Rough lathe, 0.3mm margin in X direction, 0.1mm margin in Z direction
N006 G01 X0 Z2; Linear to the start of the cycle (0,2)
N007 G03 X20 Z-10 R10; Turn the tool counterclockwise (20, -10); R6 Activity Chuck

N008 G01 Z-26.5; Straight road (20, -26.5)
N009 X25; Straight road (25, -26.5)
N010 U2, Z-1; Straight point (27,27.5)
N011 W-22; Straight point (25, -49.5)
N012 X32; Point from straight line (32, -49.5)
N013 G03 U4 W-2 R2; Turn counterclockwise to a point (36, -51.5); R2
N014 G01 W-13; Straight point (36, -64.5)
N015 X44; Straight to points (44, -64.5)
N016 U2 W-1; Direct point (46, -65.5)
N017 Z-68; Straight road (46, -68.5)
N018 G00 X100 Z50; Quick positioning to tool change point
N019 X0 Z2 is quickly at the beginning of the loop
N020 G70 P006 Q018F0.15; Complete external contour
N021 G00 X100 Z50; Quick positioning to tool change point
N022 G21 G99 G97 G40; Initialization procedure
N023 M03 S500 T0505; Spindle forward rotation, speed 500, 5th order knife, tool correction
N024 G00 X38 Z-49.5; Quickly place in slot
N025 G01 X23; Grooving
N026 X38; Retreat point (38, -49.5)
N027 G00 X100 Z50; Quick positioning to tool change point
N028 G21 G99 G97 G40; Initialization procedure
N029 M03 S800 T0606; Spindle rotation, speed 800, No.6 knife, tool compensation
N030 G00 X30 Z-25; Quick Positioning (30, -25)
N031 G92 X26.2 Z-47 F1.5; Processed thread
N032 × 25.7; Processed thread
N033 × 25.4; Processed thread
N034 X25.2; Processed thread
N035 X25.05; Processed thread
N036 G00 X100 Z50; Quick positioning to tool change point
N037 MO3; Spindle stop
N038 M05; The program has stopped