JP2023108406A - Tool attachment and coolant jet system - Google Patents

Abstract

To provide a tool attachment which can inhibit heat generation of a cutting portion by using a general purpose machine and remove chips from the cutting portion.MEANS FOR SOLVING THE PROBLEM: A tool attachment 10 is attached with a cutting tool CT which cuts a workpiece WP and has a first coolant hole part HO in which a coolant flows. The tool attachment 10 includes: a tool holder 11 having an attachment part 12 attached to the general purpose machine and a holding part 11a which holds the cutting tool: a tool adhesion pipe 16 for allowing the coolant to communicate with an end of the first coolant hole part HO of the cutting tool CT; and an adhesion pipe holder 15 which is attached to the tool holder 11 and holds the tool adhesion pipe 16.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a tool attachment and coolant injection system mounted on a general purpose machine tool.

In cutting, heat is generated because a rotating cutting tool comes into contact with a workpiece, and this heat may cause problems such as damage to the blade of the cutting tool and thermal deformation of the cut part of the workpiece. In cutting, chips generated by cutting may be caught between the blade of the cutting tool and the workpiece.

In order to suppress the heat generated by cutting and to flush chips out, there has been proposed a technique of externally applying or spraying a coolant to the blade of a cutting tool, as disclosed in Patent Document 1. Further, as disclosed in Patent Document 2, a technique has been proposed in which coolant is sprayed from a cutting tool having coolant holes by passing the coolant through a spindle device of a machining center.

However, in general-purpose machine tools such as lathes, it has not been proposed to use a cutting tool having a coolant hole to carry out cutting (especially inner diameter machining such as female screw machining or hole machining). General-purpose machine tools cannot supply coolant to the machined part (inside) or allow chips to flow out during drilling, internal threading, etc., resulting in poor cutting and poor accuracy in the workpiece. something happened.

Utility Model Registration No. 3186496 Japanese Patent Application Laid-Open No. 2008-12619

In view of the circumstances as described above, the present invention provides a tool attachment and a coolant injection system capable of suppressing heat generation in a machined part using a general-purpose machine tool and removing chips from the machined part. The challenge is to

This embodiment is a tool attachment for attaching a cutting tool that cuts a workpiece and has a first coolant hole through which coolant flows. The tool attachment includes a tool holder having an attachment part attached to a general-purpose machine tool and a holding part for holding a cutting tool, a tool tight pipe for communicating coolant with the end of the first coolant hole of the cutting tool, and a tool tight fitting. a tight tube holder for holding the tube.

The tool tight fitting pipe has an elastic member having a second coolant hole through which coolant mist flows at the tip of the tool tight fitting pipe that is in contact with the end of the first coolant hole. It is preferred to have 3 coolant holes.
Moreover, it is preferable that the tool tight-fitting tube is movable with respect to the tight-fitting tube holder.
As for the movement, the tool contact tube and the contact tube holder may be screwed together, and the movement of the tool contact portion with respect to the contact tube holder may be by rotation of the screw. Alternatively, a spring may be arranged between the tool contact tube and the contact tube holder, and the movement of the tool contact portion with respect to the contact tube holder may be due to the elastic force of the spring.

This embodiment is a coolant injection system that jets mist onto a cutting tool having a first hole. A coolant injection system includes a tool holder having a mounting portion attached to a general-purpose machine tool and a holding portion for holding a cutting tool having a first hole, and a tool for communicating coolant to the end of the first hole of the cutting tool. a tightness tube, a tightness tube holder that holds the tool tightness tube, a lubricator connected to the tool tightness tube, a coolant tank that supplies coolant to the lubricator, a first passage for the lubricator, and a second passage for the coolant tank. and a branching unit for branching into and supplying gas to each.
The cross-sectional area of the first passage of the branching unit is preferably smaller than the cross-sectional area of the second passage.

The tool attachment and coolant injection system according to the present embodiment can effectively suppress heat generation of the cutting tool and the machined part, and can remove chips from the machined part.

1 is a perspective view of a general-purpose machine tool with a coolant injection system according to the present embodiment; FIG. (a) is a plan view showing a tool attachment that is an embodiment, and (b) is a front view and a side view of a tool holder. (a) and (b) are a first example of a tool tight-fitting tube and a tight-fitting tube holder that holds the tool tight-fitting tube. (c) and (d) are a second example of the tool tight-fitting tube and the tight-fitting tube holder that holds the tool tight-fitting tube. 3 is an external perspective view of a coolant injection device 30 and a lubricator 40. FIG. 3 is a conceptual cross-sectional view of a coolant injection device 30 and a lubricator 40; FIG.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each drawing used for explanation is schematically shown to the extent that these inventions can be understood, and the size, angle, thickness, etc. may be exaggerated. In addition, in each drawing used for explanation, the same component may be denoted by the same number, and the explanation thereof may be omitted. Also, the shapes, dimensions, materials, etc. described in the following embodiments are merely suitable examples.

[General-purpose machine tools]
FIG. 1 is a perspective view of a general-purpose machine tool with a tool attachment and a coolant injection device according to the present embodiment. Using the general-purpose machine tool MT, an operator chucks the workpiece WP with the chuck CH, clamps the tool attachment 10 with the tool rest TH, and processes the workpiece WP with the cutting tool CT. The chuck CH is rotated by a drive unit (not shown), and the fixed cutting tool CT moves on the carriage CA, so that the cutting tool CT comes into contact with the workpiece WP and cuts the workpiece WP. A hose is connected to the tool attachment 10 and connected to a coolant injection device 30 . The coolant injection device 30 stores coolant and further has a lubricator 40, and sprays the coolant with a gas such as air supplied to the coolant injection device 30 from a compressor (not shown). In the present embodiment, the tool attachment 10 and the coolant injection device 30 are collectively referred to as a coolant injection system.

In the present embodiment, when the cutting tool CT has the first hole through which the coolant flows, the coolant is sprayed from the cutting tool CT, thereby suppressing heat generation in the cutting portion of the workpiece WP. and remove chips from the machined part. This embodiment can cut the inner and outer diameter machining portions of the workpiece WP. Or suitable for inner diameter machining.

<Tool attachment and cutting tool>
FIG. 2(a) is a plan view showing the tool attachment 10, in which the cutting tool CT is attached. In FIG. 2(a), the workpiece WP is drawn in a cross-sectional view so as to make the cutting tool CT easier to see. The tool attachment 10 consists of a tool holder 11, a tool contact tube 16, and a contact tube holder 15 that holds the tool contact tube. A contact tube holder 15 is fastened to the tool holder 11 by fastening means such as bolts.

〔Cutting tools〕
The cutting tool CT is attached to the tool holder 11 of the tool attachment 10 at its base end side. A tool bit TB is attached to the tip side (−X axis side) of the cutting tool CT to cut the workpiece WP. The cutting tool CT has a tool bit TB, a shank as a body, a base held by the tool holder 11, and a first coolant hole HO penetrating through the center of the shank. The cutting tool CT can be applied to, for example, taps, drills, end mills, etc., as long as it has the first coolant hole HO.

The first coolant hole portion HO is formed from the end face of the base portion on the rear end side (+X axis side) toward the tip side to which the tool bit TB is attached. In this embodiment, the diameter of the first coolant hole portion HO is constant in the shank portion, and the diameter of the first coolant hole portion HO is smaller on the tip end side. However, it is not limited to this, and the diameter of the first coolant hole portion HO may be a taper that gradually decreases from the base toward the tip side, or the first coolant hole portion from the base to the tip side (-X axis side). The diameter of HO may be constant. By reducing the diameter on the tip side, the pressure of the mist ejected from the tip can be effectively increased, and the mist can be sprayed at a relatively high pressure over a wide range. The end surface of the base of the cutting tool CT is in close contact with a tool contact tube 16, which will be described later.

[Tool holder]
FIG. 2(b) is a front view and a side view of the tool holder 11. FIG. The tool holder 11 has a mounting portion 12 and a holding portion 11a that holds the cutting tool CT. The tool holder 11 is preferably made of cast iron or the like, which has high wear resistance and damping properties. The mounting portion 12 is a protrusion for clamping to the tool rest TH of the general-purpose machine tool MT. The attachment portion 12 may have a shape other than that shown in FIG.

The holding portion 11a shown in FIG. 2B has a circular cross section and a shape extending in the X-axis direction. The diameter of the holding portion 11a can be appropriately changed according to the diameter of the shank of the cutting tool CT. When the cutting tool CT has a hexagonal or quadrangular cross section, the holding portion 11a may also have a hexagonal or quadrangular cross section. A plurality of screw holes 11b into which fastening means (not shown) such as screws and bolts are inserted are formed on the upper side of the holding portion 11a. The cutting tool CT held by the holding portion 11a is fastened by fastening means.

[Tool adhesion tube and adhesion tube holder]
FIG. 3(a) is a front view of the tool contact tube 16 and the contact tube holder 15 of the first example, and FIG. 3(b) is a cross-sectional view taken along the line bb. FIG. 3(c) is a front view of the tool tight-fitting tube 16 and the tool tight-fitting tube holder 15 of the second example, and FIG. 3(d) is a cross-sectional view taken along line dd. The tool contact tube 16 and the contact tube holder 15 are preferably made of cast iron or the like, which has high wear resistance and damping properties.

First, the first example will be explained. The tight fitting tube holder 15 holds the tool tight fitting tube 16 and is fastened to the tool holder 11 by a bolt or the like that enters the fastening hole 15d. An O-ring groove 15b into which an O-ring or, which is an elastic member, is fitted is formed in the tip surface 15a that contacts the tool holder 11. As shown in FIG. This is to prevent leakage of coolant mist, which will be described later, and if there is no or little leakage of coolant mist, the O-ring groove 15b may not necessarily be provided.

The tight fitting tube holder 15 has a cylindrical groove 15c that movably holds the tool tight fitting tube 16. As shown in FIG. The diameter of this cylindrical groove 15 c is slightly larger than the maximum diameter of the tool tight tube 16 . A screw groove 15d is formed through the rear end face of the cylindrical groove 15c.

A seal packing 17 made of an elastic member such as rubber is adhered to the head portion 16a of the tool tight-fitting tube 16 with an adhesive. The seal packing 17 may be fixed by screwing or the like instead of adhesive. The diameter of the seal packing 17 is slightly smaller than the diameter of the cylindrical groove 15c. The seal packing 17 is formed with a second coolant hole 17c through which coolant mist flows.

The diameter of the head portion 16a of the tool tight fitting tube 16 is slightly smaller than the diameter of the cylindrical groove 15c, and an O-ring groove 16f in which an O-ring or is fitted is formed on the outer periphery of the head portion 16a. If there is no or little leakage of coolant mist, the O-ring groove 16f may not necessarily be provided. A third coolant hole portion 16c through which coolant mist flows is formed in the body portion 16b of the tool tight fitting tube 16 from the head portion 16a to the body portion 16b. A screw groove 16e to which a hose coupler is attached is formed at the rear end (+X-axis side) of the third coolant hole portion 16c. A thread groove 16d is formed on the outer periphery of the body portion 16b of the tool tight fitting tube 16 so as to be screwed with the thread groove 15d. When the operator rotates the body portion 16b, the tool contact tube 16 and the seal packing 17 move in the front-rear direction (X-axis direction).

The surface of the seal packing 17 comes into close contact with the end surface of the base of the cutting tool CT as the tool contact tube 16 moves to the tip side (−X axis side). Further, the positions of the first coolant hole portion HO of the cutting tool CT and the second coolant hole portion 17c of the seal packing 17 match. Moreover, since the seal packing 17, which is an elastic member, is compressed with a predetermined pressure, there is almost no gap between the surface of the seal packing 17 and the end surface of the base of the cutting tool CT. Therefore, the coolant mist smoothly flows from the second coolant hole portion 17c to the first coolant hole portion HO, and almost no coolant mist leaks out from between the surface of the seal packing 17 and the end surface of the base portion of the cutting tool CT.

Next, the second example will be described, but the description of parts and structures that overlap with those of the first example will be omitted. The thread groove 16 d of the tool contact tube 16 of the first example rotates with respect to the thread groove 15 d of the contact tube holder 15 , so that the tool contact tube 16 moves forward and backward (X-axis direction) with respect to the contact tube holder 15 . moved. In the second example, the contact tube holder 15 does not have the thread groove 15d, and the tool contact tube 16 does not have the thread groove 16d. Instead, in the second example, the inner peripheral surface 15g of the tight fitting tube holder 15 is mirror-finished, and the outer peripheral surface 16g of the barrel portion 16b of the tool tight fitting tube 16 is mirror-finished. Instead of mirror-finishing the inner peripheral surface 15g and the outer peripheral surface 16, the inner peripheral surface 15g and the outer peripheral surface 16 may be finished with a tape treated with silicon, polyethylene, or fluorine. Since there is no thread groove, the head 16a of the tool contact tube 16 is in close contact with the end surface of the base of the cutting tool CT, so that the spring 18 is arranged around the body 16b of the tool contact tube 16.

The seal packing 17 was arranged in the tool contact tube 16 of the first example, but the tool contact tube 16 of the second example does not have the seal packing 17, and an O-ring groove 16h in which an O-ring is fitted is formed in the tip surface. It is Further, a projection 16i is formed on the head portion 16a of the tool tight fitting tube 16 so that the third coolant hole portion 16c extends toward the tip side. The protrusion 16i is formed with a diameter that allows it to enter the first coolant hole HO.

The tool contact tube 16 moves to the tip side (−X axis side), the O-ring of the O-ring groove 16h comes into close contact with the end surface of the base of the cutting tool CT, and the projection 16i enters the first coolant hole HO. Since the protrusions 16i enter the first coolant hole HO, the coolant mist smoothly flows from the second coolant hole 17c to the first coolant hole HO. Even if the coolant mist leaks out from the gap between the projection 16i and the first coolant hole HO, the O-ring in the O-ring groove 16h is compressed with a predetermined pressure, so there is almost no possibility that the coolant mist leaks out. .

Although not described in detail as a third example, the contact tube holder 15 and the tool contact tube 16 may be arranged by combining the seal packing 17 of the first example and the spring 18 of the second example.

[Coolant injector]
4 is an external perspective view of the coolant injection device 30 having the lubricator 40. FIG. The coolant injection device 30 has a coolant tank 31 that stores coolant, a tank lid 32 , a branching unit 33 that branches the compressed gas, and a lubricator 40 . The coolant tank 31 preferably has strength to withstand the pressure of the compressed gas. It also preferably has a flow meter (not shown) so that the amount of coolant stored can be visually checked.

The tank lid 32 is a screw lid that is opened when the coolant is put into the coolant tank 31 and is closed when the coolant is injected. The branch unit 33 has a first passage 36 branching the compressed gas to the lubricator 40 side and a second passage 35 branching to the coolant tank 31 side. The lubricator 40 uses compressed gas to generate coolant mist from the coolant in the coolant tank 31 . Coolant mist is supplied to the tool tightness tube 16 via the hose coupler 38 and the hose 39 .

FIG. 5 shows a conceptual flow of compressed gas, coolant, and coolant mist in the coolant injection device 30 and the lubricator 40, and also shows a conceptual cross-sectional view of the coolant injection device 30 and the lubricator 40. As shown in FIG.

The coolant tank 31 is a metal or plastic tank that stores several liters to several tens of liters of coolant CL. The coolant CL is generally classified broadly into water-soluble cutting oil and water-insoluble (oil-based) cutting oil, either of which can be used in this embodiment. Coolant CL means a substance used for cooling, lubricating, and removing chips from the cutting portion during machining. A branch unit 33 and a lubricator 40 are attached to the upper side of the coolant tank 31 .

The branching unit 33 branches compressed gas (such as air) supplied from a compressor (not shown) or the like into a first passage 36 having a diameter ΦB and a second passage 35 having a diameter ΦA. The first passage 36 diverts the compressed air to the lubricator 40 side, the first passage 36 diverts the compressed gas to the lubricator 40 side, and the second passage 35 diverts the compressed gas into the coolant tank 31 . The cross-sectional area of the first passage 36 is preferably smaller than the cross-sectional area of the second passage 35. For example, the cross-sectional area ratio is preferably 4/5 to 1/10, and the cross-sectional area ratio is 1/2 to 1/10. 1/8 is preferred. That is, according to Bernoulli's law, the pressure on the side of the lubricator 40 decreases and the pressure on the side of the coolant tank 31 increases.

The lubricator 40 has a main body 41 , a check valve 42 , a coolant adjustment valve 43 , a coolant dropping chamber 44 and a coolant pipe 45 . The primary side of body 41 communicates with first passage 36 and the secondary side 41a of body 41 communicates with hose coupler 38 (FIG. 4). The check valve 42 diverts part of the compressed gas supplied to the lubricator 40 side into the coolant tank 31 . The check valve 42 is generally included in a commercially available lubricator 40, but the check valve 42 may be omitted in this embodiment. The coolant adjustment valve 43 is a valve that adjusts the amount of coolant CL supplied from the coolant pipe 45 . The coolant dripping chamber 44 drips the coolant CL supplied through the coolant adjustment valve 43, and the compressed gas flowing through the lubricator 40 turns the dripped coolant CL into a mist.

Since several liters to several tens of liters of coolant CL are used in cutting, the capacity of the coolant tank 31 is also required to be able to store an equivalent amount of coolant CL. With only the lubricator 40 (not including the branch unit 33), the ability to suck up the coolant CL cannot keep up with the capacity of several liters or more, and the amount of coolant mist generated becomes unstable. Also, with the lubricator 40 alone, coolant mist is not generated for several minutes when starting cutting or changing cutting tools.

In the present embodiment, high-pressure compressed gas is supplied into the coolant tank 31 through the second passage 35 having a large cross-sectional area, so the coolant CL in which the compressed gas is stored is pushed out to the coolant pipe 45 . Therefore, in the present embodiment, coolant mist is generated immediately after starting the cutting process or immediately after changing the cutting tool.

The coolant mist cools the cutting tool CT while passing through the first coolant hole HO of the cutting tool CT. Also, the coolant mist is ejected from the tip of the cutting tool CT to remove chips from the cutting portion. In particular, it is suitable for removing chips that remain on the machined portion in inner diameter machining (drilling, drilling, grooves, internal threads).

[Other embodiments]
The branching unit 33 described above has a first passage 36 with a diameter ΦB and a second passage 35 with a diameter ΦA, and the cross-sectional area of the first passage 36 is smaller than the cross-sectional area of the second passage 35. . Without being limited to this, the branch unit 33 may have the first passage 36 and the second passage 35 with the same diameter, and the throttle valve may be arranged in the first passage 36 . By tightening the throttle valve by the operator, the cross-sectional area of the first passage 36 can be varied so as to be smaller than the cross-sectional area of the second passage 35 . By tightening the throttle valve according to the viscosity of the coolant CL, the type or size of the workpiece, or the type of cutting tool, the amount of coolant mist and the ratio of coolant and compressed gas can be adjusted. can.

In the above-described embodiment, the tool holder 11 and the tight fitting tube holder 15 are formed of separate members and fastened by fastening means, respectively. may have been Although the tool attachment 10 and the coolant injection device 30 are connected by a hose, the rear end of the third coolant hole portion 16c and the secondary side 41a of the lubricator main body 41 may be connected without a hose.

DESCRIPTION OF SYMBOLS 10... Tool attachment, 11... Tool holder, 11a... Holding part 15... Adhesion pipe holder, 16... Tool adhesion pipe, 16a... Head, 16b... Body part 16c... 3rd coolant hole part, 16i... Protrusion 17... Seal packing , 17c... Second coolant hole 18... Spring 30... Coolant injector 31... Coolant tank 33... Branch unit 32... Tank cover 35... Second passage 36... First passage 38... Hose coupler 39... Hose 40... Lubricator, 41... Main body, 42... Check valve,
43 Coolant adjusting valve 44 Coolant dripping chamber 45 Coolant pipe CT Cutting tool TB Tool bite HO First coolant hole

Claims (6)

A tool attachment for mounting a cutting tool that cuts a workpiece and has a first coolant hole through which coolant flows,
a tool holder having a mounting portion attached to a general-purpose machine tool and a holding portion holding the cutting tool;
a tool tight-fitting tube for communicating the coolant with the end of the first coolant hole of the cutting tool;
a tight fitting tube holder that holds the tool tight fitting tube;
A tool attachment with The tool contact pipe has an elastic member having a second coolant hole through which coolant mist flows, at the tip of the tool contact pipe in contact with the end of the first coolant hole,
2. The tool attachment according to claim 1, wherein the tool tight-fitting tube has a third coolant hole through which coolant mist flows. 3. A tool attachment according to claim 1 or 2, wherein said tool tight-fitting tube is movable with respect to said tight-fitting tube holder. The tool contact tube and the contact tube holder are screwed together, and the movement of the tool contact portion with respect to the contact tube holder is caused by rotation of a screw, or
4. A tool attachment according to claim 3, wherein a spring is arranged between said tool contact tube and said contact tube holder, and movement of said tool contact portion with respect to said contact tube holder is caused by elastic force of said spring. . a tool holder having a holding portion for holding a cutting tool having an attachment portion to be attached to a general-purpose machine tool and a first hole portion;
a tool tight-fitting tube for communicating the coolant with the end of the first hole of the cutting tool;
a tight fitting tube holder that holds the tool tight fitting tube;
a lubricator connected to the tool tightness tube;
a coolant tank that supplies coolant to the lubricator;
a branch unit that branches into the first passage for the lubricator and the second passage for the coolant tank and supplies gas to each of them;
with
A coolant injection system for spraying mist onto the cutting tool having the first hole. 6. The coolant injection system according to claim 5, wherein the cross-sectional area of said first passage of said branch unit is smaller than the cross-sectional area of said second passage.