JP2798379B2 - Tool holder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool holder, and more particularly, to a coolant through type tool having an adjusting screw for positioning a rear end of a cutting tool in a liquid supply hole penetrating an axial center portion. Regarding the holder.

[0002]

2. Description of the Related Art Generally, in a tool holder used for attaching a cutting tool to a main shaft of a machine tool,
The adjusting screw is screwed into a female screw formed in the shaft hole of the holder, and is used to determine the protrusion length of the tool by making the rear end of the cutting tool abut on the front end surface. Further, when the tool holder is of a coolant through type, it is required that the coolant supplied to the liquid supply hole penetrating through the axis of the holder flows into the tool while maintaining a sealing effect so as not to leak outside. .

Conventionally, this type of adjustment screw is made of metal or resin. However, when using metal, the sealing effect cannot be exerted between the external thread at the outer periphery and the internal thread at the liquid supply hole. Had a fear.

[0004] For this purpose, Japanese Patent Application Laid-Open No. H08-141878 proposes that the outer peripheral thread portion of a metal adjusting screw and a tool contact surface are coated with a flowing rubber. However, simply coating the entire outer peripheral thread portion with the flowing rubber thinly causes the covering portion to be deformed or broken with respect to the high-pressure coolant, so that a sufficient sealing effect cannot always be obtained. In addition, although the taper surface at the tip of the adjusting screw is coated with the flowing rubber for the purpose of sealing, the thickness of the coating with the flowing rubber is insufficient and the tool is broken by the pressing force at the rear end of the tool. have.

On the other hand, the present applicant has proposed an adjusting screw comprising a combination of a metal member and a resin member in JP-A-8-47840 and JP-A-8-118197. In this case, a sealing effect based on the elasticity of the resin member and an attachment strength based on the rigidity of the metal member can be secured. However, since it is composed of two components, it is inconvenient to handle and the cost increases.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a sealing effect and a sufficient mounting strength, which do not break even when abutting against the rear end of a cutting tool, are easy to handle, and reduce costs. To provide a tool holder provided with an adjusting screw.

In order to achieve the above object, the present invention provides a tool holder in which an adjusting screw is screwed into a liquid supply hole penetrating a shaft center portion, wherein the adjusting screw is integrally inserted into the mandrel and the mandrel. It consisted of a molded elastic material. The cored bar is formed with a through hole having a jig receiving portion at the axial center portion, a tapered seat surface that expands outward at the tip end surface, and a partial outer peripheral portion flush with the outer peripheral surface of the elastic material. A protruding protrusion is formed. The elastic material covers the outer peripheral portion and the tapered seat surface from a rear portion of the core metal with a predetermined thickness, and a male screw is formed on the outer peripheral surface integrally with the protruding portion of the core metal.

In the present invention, the outer peripheral surface of the adjusting screw is formed of an elastic material having appropriate elasticity and a partially exposed high-rigidity metal material, and a single male screw is formed. The male screw is screwed into a female screw formed in the liquid supply hole of the tool holder. Therefore, the sealability of the outer peripheral surface is ensured by the elastic material, and the rigidity of the metal core does not cause deformation or breakage even if the coolant is supplied at a high pressure. In addition, since the elastic material is covered by outsert molding on the tapered seat surface at the tip of the adjusting screw, the coating thickness can be set sufficiently thick, and the cutting tool does not break even when the rear end is pressed against it. Good sealing performance.

That is, according to the present invention, by integrally connecting a metal material and an elastic material, an adjusting screw having both necessary rigidity and elasticity can be obtained. And is very easy to handle.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a tool holder according to the present invention will be described below with reference to the accompanying drawings.

In FIG. 1, a tool holder according to the present invention comprises a tapered portion 11, a manipulator holding portion 21, and a shaft portion 3.
1 and a chuck 40, and a liquid supply hole 12 penetrating through the shaft center portion is provided with a pull bolt 13 and an adjustment screw 5.
0 is screwed.

The tapered portion 11 is a portion mounted on a main shaft of a machine tool such as a machining center. The pull bolt 13 is screwed into the female screw 12 a of the liquid supply hole 12, and has a through hole 14 at the axis. The manipulator holding portion 21 is a portion in which a V-shaped groove 22 is formed in an annular shape on the outer peripheral surface.
2 is gripped by the manipulator of the automatic tool changer. Further, concave portions 23, 23 in which the positioning claws on the main shaft side are fitted are formed in the outer peripheral portion of the holding portion 21.

The chuck 40 has a well-known structure in which a collet 42 is compressed by fastening a nut 41 to the tip of the shaft portion 31 and a cutting tool (drill) 60 is held. The drill 60 has liquid supply holes 61 penetrating from the rear end face to the cutting edge, and the rear end is positioned by an adjusting screw 50 described in detail below.

The adjusting screw 50 is shown in FIGS.
As shown in the figure, a metal (for example, JIS standard, S45
C) and a resilient material (for example, urethane, silicon, or rubber) 55. The cored bar 51 has a through-hole 52 having a hexagonal hole 52a for receiving a hexagonal wrench at the shaft center, a tapered seating surface 53 that expands outward at a tip end surface, and an outer periphery of an elastic material 55 at an outer periphery. A projecting portion 54 projecting flush with the surface is formed. This protrusion 5
Four recesses 54a are formed at equal intervals in four portions. The elastic member 55 is formed by integral outsert molding with the cored bar 51, and covers the outer peripheral surface and the tapered seating surface 53 from the rear end of the cored bar 51 through the concave portion 54a. This elastic material 5
5 is exposed on the outer peripheral surface of the metal core 5 in a flush manner, and one male screw 59 screwed into the female screw 12 b of the liquid supply hole 12.
Are formed.

The adjusting screw 50 having the above configuration is inserted into the liquid supply hole 12 from the tip of the shaft portion 31 with the chuck 40 and the drill 60 removed.
The male screw 59 is screwed to the female screw 12b to a predetermined depth while a hexagon wrench (not shown) is engaged with the hexagon hole 52a and rotated. Next, the chuck 40 is mounted, and the drill 60 is inserted until the rear end thereof comes into contact with the elastic material tapered portion 55 a of the adjuster screw 50, and the nut 41 is tightened. At the time of cutting, the coolant is supplied from the machine spindle, and the through hole 14 of the pull bolt 13 and the liquid supply hole 12 are provided.
And the supply holes 61 of the drill 60 through the through holes 52.
Erupts from

In the adjusting screw 50, the elastic material 55 having appropriate elasticity is screwed into the female screw 12b of the liquid supply hole 12, so that the sealing effect at this portion is sufficient. Moreover, not only the elastic member 55 but also the protruding portion 5 of the high rigidity core metal 51 is provided.
4 also has a sufficient screwing strength because it is partially screwed into the female screw 12b. Assuming that the female screw 12 is
If the screw is screwed to b, when the supply pressure of the coolant is high, the male screw 59 may be deformed or broken, but the adjusting screw 50 does not have such a risk.

Further, since the rear end of the cutting tool is received by the tapered portion 55a, even if the tools have different diameters, the positioning can be performed with good sealability, and the coolant can flow into the liquid supply hole 61 without fail. In particular, since the elastic material 55 is covered by the core metal 51 by outsert molding, a large thickness can be formed in the tapered portion 55a, and the tapered portion 55a does not break even when the rear end of the tool is pressed. . Also, the core metal 51
Since the elastic member 55 and the elastic member 55 are integrally formed without being separated, the handling is convenient and the cost is reduced.

FIG. 4 shows another example of the adjusting screw 50. In this example, in order to enable the outsert molding of the elastic material 55 integrally with the outer peripheral portion of the
4, four holes 54b parallel to the axial direction were formed at equal intervals.
Another configuration is the adjusting screw 5 shown in FIGS.
It is the same as 0, and the same parts are denoted by the same reference numerals. The effect of the adjusting screw 50 is shown in FIG.
This is the same as that shown in FIG.

The tool holder according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention. For example, a tool holder without the manipulator holding portion 21 of the automatic tool changer may be used.
The structures of the pull bolt 13 and the chuck 40 are arbitrary.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a tool holder according to the present invention.

FIGS. 2A and 2B show an adjusting screw used in the tool holder, wherein FIG. 2A is an external perspective view and FIG. 2B is a partially cut perspective view.

3A and 3B show the adjusting screw, wherein FIG. 3A is a front view, FIG. 3B is a BB cross-sectional view, and FIG. 3C is a CC cross-sectional view.

FIG. 4 shows another example of the adjusting screw, and (A)
Is a sectional view, and (B) is a front view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 ... Taper part 12 ... Liquid supply hole 40 ... Chuck 50 ... Adjust screw 51 ... Core metal 52 ... Through hole 52a ... Hexagon hole 53 ... Taper seat surface 54 ... Protruding part 55 ... Elastic material 55a ... Taper part 59 ... Male screw

Claims (1)

(57) [Claims] 1. A tool holder comprising a cutting tool mounting chuck at a tip, a tapered portion mounted on a main shaft of a machine tool at a rear portion, and an adjusting screw screwed into a liquid supply hole passing through a shaft center portion. The adjusting screw is made of a core metal and an elastic material integrally formed with the core metal by outsert molding. The core metal has a through hole having a jig receiving portion at a shaft center portion, and an outer end formed at a tip end surface. A tapered seat surface that expands toward
A protrusion is formed on an outer peripheral portion of the elastic member so as to partially protrude from an outer peripheral surface of the elastic material. The elastic material covers an outer peripheral portion and a tapered seat surface with a predetermined thickness from a rear portion of the cored bar. And a male screw formed integrally with the protruding portion of the core bar on an outer peripheral surface.