CN2157860Y - Bamboo double worm screw - Google Patents

Abstract

The utility model relates to a special twist drill for bamboos and woods. The cross section of a cutting work part mainly forms an inverse S shape. The thickness K of a core is 0.25d. The capacity of a chip removal tank corresponding to a tank is large. Thus, the utility model has the characteristics of easy manufacture, good centering and chip removal performances, fast cutting and feeding speed, good boring precision and smoothness, etc. The utility model is a drilling tool appreciated by factories of bamboos, woods, etc.

Description

Bamboo double worm screw

The utility model belongs to a kind of fluted drill, the special-purpose fluted drill of especially a kind of drilling bamboo and wood products.

Bamboo and wood products increases on the market in recent years, and bamboo wood process tool demand also increases greatly thereupon.But because existing market is not seen special-purpose bamboo wood screw drill as yet, many producers still use the general straight shank twist drill of metal cutting (as shown in Figure 1), and this fluted drill drift angle 2 φ are about 118 °, and back angle is generally less than 20 °.So, although its rigidity and intensity are better, when the drilling bamboo product, the centering ability, chip pocket is too little and easily blocked, makes it caloric value and increases, and then influence feed speed.Therefore, also some producer uses this fluted drill always, and it is little to adopt manual method that the reconditioning of apex point drift angle is changed, and grinds off the part knife back, increases back angle.Like this, the chip removal performance in centering and when beginning boring makes moderate progress, but after piercing certain depth, still has the chip pocket phenomenon that is blocked.And the bamboo carpenter adopts easy chit drill (as shown in Figure 3).It has advantages of simple structure and simple, but because of the cutting anterior angle of drill bit is 0 °, does not have the helicla flute chip removal again, and its borehole accuracy, fineness and feed speed all are subjected to bigger influence.

In addition, Jiangxi Measuring ﹠ Cutting Tools Factory has applied for a kind of depth twist drill patent (number of patent application 88204129), adopts the chip pocket of broad, and the thick brill cored structure of bigger helical angle and zero draft has solved the chip removal problem of gun drilling preferably; But owing to bore the thick K=(0.4-0.6 of core) d, drill point angle big (2 φ=135 °), thus suitable processing metallic, and it is not good enough to process flexible article effect such as bamboo wood.

It is simple that the purpose of this utility model provides a kind of manufacturing, and centering and chip removal performance are good, and it is fast to cut feed speed, and borehole accuracy and fineness bamboo wood screw drill preferably.

The utility model mainly is at the characteristics than soft material such as cutting bamboo wood, adopts thin core thick [for example, apart from the thick K=(0.15-0.30 of core at apex point 1d place) d, wherein d is the fluted drill diameter] and less cutwork cross-sectional area partly; For the brill commonly used that clockwise cutting turns to, its shape of cross section is anti-S shape (as Fig. 6, shown in Figure 9); Simultaneously, in order to improve the feed speed of centering stability and cutting, drill point angle is reduced to 2 φ=65 °-90 °, back angle α=25 °-45 °, and apex point is Shape, its both sides edge is slightly recessed to be near linear shape; For the thicker drill bit of diameter, two cutting edges also can be made into tangible indent and are the mountain font, its drill point angle 2 φ ₁=(30 °～65 °) (as shown in figure 10).Wherein, it is more convenient that the former makes reconditioning, and the latter is acute angle because of both sides nose angle ε, thereby further improve the sharp of drill lip and be drilled to the fineness etc. in hole.In addition, for remedying the problem of the drilling rod rigidity deficiency that chip pocket produces greatly, brill core thickness can adopt big increment, and generally to can be taken as every 100mm be (1.8～2.5) mm to its increment.

The utility model is described in further detail below in conjunction with drawings and Examples.

Fig. 1 is a kind of structure diagram of existing general straight shank twist drill.

Fig. 2 is the side view of Fig. 1.

Fig. 3 is a kind of structure diagram of existing bamboo wood chit drill.

Fig. 4 is a kind of depth twist drill structure diagram.

Fig. 5 is a kind of structure diagram of bamboo wood screw drill.

Fig. 6 is the side view of Fig. 5.

Fig. 7 is that the G of Fig. 5 is to partial view.

Fig. 8 is the local longitudinal sectional drawing of Fig. 5.

Fig. 9 is the A-A profile of Fig. 5.

Figure 10 is the apex point structure diagram of another kind of bamboo wood screw drill.

The utility model can adopt the W6Mo5Cr4V2 high-speed steel to reach required diameter through wire drawing; And thrust into stub, and wear into 90 ° of cone angles for one, the 45 ° of chamferings in other end again through vacuum heat, reach more than the HRc62 hardness.Wear into the zero draft optical wand of φ 1.6mm then with centerless grinder, again according to designing requirement, grind spiral helicine chip area (2) with emery wheel integral body, grooved can form (for example 7,8 indication line styles are the circular arc line style among Fig. 9) by two reverse tangent circular arc line style rotations, form cutwork part (1) thus, the shape that makes it cross section (5) is the anti-S shape of approximate uniform thickness.The thick 0.4mm of the thick K of core at distance apex point (4) end face 1d place, and the thick increment that thickens 2.5mm by every 100mm of core to straight handle section (3) direction by increasing, back angle α is 30 ° (as Fig. 5 to shown in Figure 10), after check, oil, goods.

Because the drift angle of this bamboo wood screw drill and back angle adopt approximate chit drill, core is thick comparatively approaching with the standard fluted drill, the opposed slot of chip area (2) holds and surpasses Parabolic depth twist drill again, and add that drill bit cross section (5) is flat anti-S shape, after the cutting edge that makes it the drill bit wedge angle ground relief angle, cutting edge promptly slightly was indent.Like this, it is more sharp that the utility model helps the both sides point of a knife, also be beneficial to when hole drill is logical, make the limit, hole of reverse side comparatively bright and clean, also satisfied simultaneously the rapid drainage of changeing a large amount of smear metals when cutting feeding at a high speed, avoided influencing feed speed from face, perhaps caused defects such as drill bit is fractureed because of chip pocket stops up, caloric value increases.Therefore, the special-purpose boring bar tool of this bamboo wood provided by the utility model will be subjected to the welcome of soft material goods producers such as bamboo and wood, aluminium, plastics deeply.

Claims (4)

1, a kind of bamboo wood screw drill that constitutes by cutwork part and staight shank, wherein the cutwork part is made up of apex point, cutting edge, brill core and helical flute etc., it is characterized in that turning to when clockwise when cutwork, cross section (5) shape of cutwork part (1) is anti-S shape; And the thick K=of core (0.15～0.3) d apart from apex point 1d place.

2, bamboo wood screw drill as claimed in claim 1 is characterized in that the apex point (4) of cutwork part (1) end is

Shape, its drill point angle 2 φ are 65 °～90 °, back angle α=25 °～45 °.

3, bamboo wood screw drill as claimed in claim 1 is characterized in that the apex point (4) of cutwork part (1) end is the mountain font, its drill point angle 2 φ ₁Be 30 °～65 °, back angle α=25 °～45 °, both sides nose angle ε is an acute angle.

4, as the described bamboo wood screw drill of claim 1 to 3, the every 100mm of increment that it is characterized in that boring the thick K of core core is 1.8～2.5mm.

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