JPS6099520A - Assembling type cylindrical cutting tool - Google Patents

Abstract

PURPOSE:To eliminate poor precision of a workpiece by planting blades, with independent cutting edges respectively, spirally on the outer periphery of a main body so as to raise rigidity and reduce vibrations of the captioned tool. CONSTITUTION:A pin hole corresponding to a driving hole for a pin 18, which positions a blade (unillustrated), is drilled in the bottom face 11 of a spiral groove and semicircular bolt hole 14 are drilled in both ends of each blade. This enables both ends of neighboring blades to be fixed by means of one bolt 21. Since complicated fitting faces of the blades and the main body are fitted right with each other and further they are combined with each other by means of the pin 18 and the bolt 21, the captioned tool has very high rigidity and rarely makes a slight vibration.

Description

[Detailed description of the invention]

The present invention relates to a cylindrical assembly-type cutting tool in which blades each having an independent cutting edge are spirally embedded in the outer peripheral surface of the main body. An integrated cutting tool that has been ground twice, such as a hob, requires fewer re-grinds due to the cam-cutting part and has a short lifespan, so various single-piece assembly tools without a cam-cutting part have been proposed. However, since the hob is a generating gear cutting tool with cutting blades arranged in a spiral pattern, space is limited in order to assemble the blade and main body, and there is a need for a means to fix the blade to the main body. is difficult. Therefore, as shown in Fig. 5, what has been proposed in the past is to separate the blade part in the axial direction and press-fit the blade (two pieces) into the main body (11) in the longitudinal direction; At both ends, connect the four rings with an annular presser foot (apply adhesive to three and screw them to the main body (one), or connect the annular ring to the main body (one and the blade) by shrink fitting or other means. In addition, as shown in Figure 6, a blade (2) is made with a set of multiple blades, and two bolts (2) are connected between the blades.
There is also a type that is connected to the main body with a screw, and a plurality of cylinders are arranged in a spiral groove formed in the main body (1).
22) 0 However, in the former case, since both ends are only forcibly fixed, the hob may float in the center during cutting or cause slight vibrations, which may cause a defective tooth profile. Furthermore, the blade (2
press fit one into the main body (one), and both i'1ffl into the main body (11
), a large amount of stress remains in the entire hob, making it susceptible to deformation. Further, in the latter case, the blades are arranged in a helical direction, and each blade is fixed at two points, but both ends are not fixed, so that when a strong cutting force is applied to both ends, slight vibrations are likely to occur. Particularly, one of the major purposes for making the blade part assembleable is to use a super hard alloy for the blade part, and in such a case, micro-vibration is particularly undesirable as it can cause chipping and chipping of the blade. In this invention, a blade positioning pin driving hole is drilled in the bottom of a spiral groove formed on the outer peripheral surface of the main body, a pin hole corresponding to the positioning pin hole is bored in the bottom of the blade, and at both ends of each blade. The present invention relates to a cylindrical assembly type cutting tool in which a semicircular bolt hole is drilled and both sides 1a of adjacent blades are fixed with a single bolt, which has excellent rigidity and good workability, except for the above-mentioned drawbacks. The aim is to provide a highly accurate assembly type tool at a low cost. An embodiment in which the cylindrical assembly type cutting tool according to the present invention is applied to a hob will be described below with reference to FIGS. 1 to 4. The main body (1) has a hole (3), a hole key (4), and an end face key (5) at the axial center of the main body (1) for attachment to a gear cutting machine (not shown). The side wall of the 0 spiral groove (9) is bored with a spiral groove (9) for inserting a blade with an axial pitch (8) equal to the axial pitch of the hob (the twist of 10 is from the groove bottom aυ to the outer circumferential surface ( 7).The IyJ ratio becomes weaker as the diameter of the groove bottom (1η and the outer circumferential surface (7) This is a relationship that is inevitably determined by determining the diameter of the blade (2).
One unit is composed of the base portions larger than that. Fourth
The one shown in the figure has one base (c) forming a blade (2) and a spiral groove.

It has a shape that can be attached to [9]. Furthermore, a bottle J is used to determine the position of the blade (2) and to absorb the cutting force exerted on the blade (2).
Drill the insertion hole α2 in the center of the grade insertion groove (9), and also drill 2 more blades than the number of blades determined by the hob tan meter at equal intervals, and insert them into both 1'f! and f of the spiral groove. Use the washer (G) for installation.At this time, the center of the pin driving hole is aligned with the axis
However, in order to drill holes so that they line up at an angle of Pa:
Axial pitch R1 bottom surface (radius N of lυ: number of grooves in the hop
γ: Torsion angle on the bottom surface β: Torsion angle on the pitch circle of the hob. Next, position the blade (2) at the wobin α pass from 11÷→−'.Furthermore, the pin hole Q2 of the bottom surface Qυ of the spiral groove is driven into the center of the bottom surface αυ of the blade (2). A matching pin hole is drilled at both ends of the blade (2), and a semicircular bolt hole and a semicircular bolt hole are provided at both ends of the blade (2) for crimping the blade (2) in the axial direction of the main body (1) with a bolt aυ. bolt hole a
Set up a space. At this time, the depth of the counterbored hole (7) is the same as that of the adjacent blade (2).
) will be tightened with one bolt, so make sure they have the same depth. Each part made in this way is first
Drive the pin a→ into the pin hole drilled at η, insert the blade (2) into the spiral groove (9) with the cutting edge facing the rotation direction of the hob, and Confirm that it fits into αE9 and push it in until the bottom surface αQ of the blade and the bottom surface α of the spiral groove are in close contact.Insert the blades (2) one after another in this way, and Insert a countersunk washer (N) into the bolt hole created at the boundary, then screw the bolt (C) into the screw hole o1 drilled on the bottom surface of the blade insertion groove and temporarily tighten.Blade When all (2) are inserted, the first and last blades (2) have many blades adjacent to the piece 1111, so use a washer with the same shape as the end of the blade (2) and a pin hole α). Insert it and pol in the same way as between the blades) ＠])
After temporarily tightening all holes (a) and (a)), complete the assembly. Play a whetstone shaped to a radius slightly smaller than 1mm radius.
By grinding in the direction of 9o0±β with respect to the longitudinal centerline of the plate (2), two surfaces with good adhesion at both ends can be obtained. ←) β is determined by the twist direction. Grade (2) side surface αfj is a bottle hole αη provided in the center of the bottom surface α of the blade on a cylinder with the same diameter as the bottom surface θ of the spiral groove.
The protruding strips adapted to the blade (
By attaching and grinding 2), it is possible to obtain a curved surface exactly the same as that of the side wall of the blade insertion groove. At this time, by leaving a small part of the strip on the jig that touches both ends of the blade (2) and removing the rest, the spiral strip and the key groove q, which is machined straight, fit together with almost no error. match. Moreover, by widening the width of the jig, any number of pieces can be ground without fail, so the grinding cost per 1 sjP is small. As described above, the present invention has a grade positioning bottle driving hole drilled at the bottom of the spiral groove, a pin hole corresponding to the positioning bottle hole drilled at the bottom of the blade, and semicircular bolts at both ends of each blade. Since the holes are drilled and both ends of adjacent blades can be fixed with a single bolt, the double-H fitting surfaces of the blade and the main body can be matched perfectly, and the bottle and bolt can also be connected. This makes it extremely rigid. In addition, because the rigidity is high, there is less slight vibration, and there is no problem with tooth profile defects (in the case of hobs, defects in the precision of the workpiece, such as jis).In addition, the blade insertion groove of the main body is precisely thread-ground. In addition, the blade fitting surface is also grounded under the same conditions as the blade insertion groove of the main body by removing the jig and attaching the ISθtAK spare at the same time, so all the blades have the same dimensions. If chipping or chipping occurs on the cutting edge during cutting, as with products, you can easily and accurately replace the grade or replace it with a spare grade without removing the hob from the hob shaft. Since it does not cause high vibrations, it is suitable for use with a throw-away method in which the cutting edge is made of cemented carbide.If you use the throw-away method, only the cutting tip can be replaced, which further improves work efficiency. As the cost increases, the total cost also decreases, making it extremely economical.

[Brief explanation of drawings]

Fig. 1 is a front view of a main body according to an embodiment of the present invention partially cut away in the helical direction, Fig. 2 is a sectional view of half of the main body, and Fig. 3 is an assembly mechanism of an embodiment of the present invention viewed from the torsional direction. FIG. 4 is a front view and partial axial sectional view of the partial assembly of the embodiment, FIG. 5 is an axial sectional view of a conventional assembled hob, and FIG.
The figure shows a part of the blade and assembly mechanism of another type of conventional assembly hob. (1)...Main body (2)...Blade (3 examples/Bob examples) Hole (7)...Outer circumferential surface (8)...Axial pitch (9)...Spiral groove 0η... Spiral groove bottom a...Bottle driving hole Q1...Screw hole a<...Bolt hole 0 o'clock...
Bottom of blade O barrel...Pin (11...Blade bottle hole (E)...Semicircular bolt hole υ...Bolt (to)...Washer ■...Cut blade agent Patent attorney Jun Kawauchi Figure 3 Figure 4 Figure 4 50 60

Claims (1)

[Claims] A cylindrical assembly type cutting tool in which a spiral groove with an axial pinch equal to the axial pitch of the blades is formed on the outer peripheral surface of the main body, a plurality of blades are inserted into the spiral groove, and the blades are fixed with bolts, A blade positioning pin driving hole is drilled at the bottom of the spiral groove, a pin hole corresponding to the positioning pin hole is drilled at the bottom of the blade, and semicircular bolt holes are drilled at both ends of each blade. , a cylindrical assembly type cutting tool characterized in that both ends of adjacent blades can be fixed with a single bolt.