Patent Description:
In particular, a cutting tool according to the preamble of independent claim <NUM> is known from document <CIT>.

The cutting tool disclosed in Patent Document <NUM> is known as a conventional cutting tool. Patent Document <NUM> discloses a cutting tool for forming a groove in an end surface of a workpiece. Such cutting tool comprises a plate member. A plate member is used to appropriately adjust the amount of projection of an edge part in accordance with the depth of a groove to be machined. Such plate member is curved as seen from a leading end side and is fixed to a tool block by means of a clamping member. When using such cutting tool, it is general to eject, from a hose, etc., coolant for cooling an edge part and to supply the coolant to the edge part.

In the case of the cutting tool disclosed in Patent Document <NUM>, if the machining proceeds so that an edge part in its entirety is arranged inside a groove of a workpiece, coolant supplied from a hose arranged outside the groove may not be able to enter the groove and thus not be able to reach the edge part. As a result, the above cutting tool has had a problem in that the edge part is heated to high temperature without being cooled, thereby being subjected to wear within a short time.

The present invention has been made in order to solve the above problem. That is, an object of the present invention is to provide a cutting tool which is capable of reliably supplying fluid to an edge part arranged inside a groove.

A cutting tool according to the present invention comprises a cutting tool according to independent claim <NUM>.

The plate member is preferably configured so as to be slidable with respect to the support member, and the cutting tool preferably also comprises fixing means for fixing the plate member.

The fixing member preferably has a pressure member which presses the plate member toward the support member and a fastening member which fastens the pressure member to the support member.

The plate member preferably has a body having a plate shape and a cutting insert having edge parts, and the cutting insert is preferably removably mounted on the body.

The present invention can provide a cutting tool which is capable of reliably supplying fluid to edge parts arranged inside a groove.

An embodiment will hereinafter be described with reference to the drawings. It should be noted that descriptions will be made with an arrow A direction in <FIG> serving as a leading end direction.

As shown in <FIG>, a cutting tool <NUM> of the present embodiment comprises a plate member <NUM>, a support member <NUM> and a fixing member <NUM>. Further, as shown in <FIG>, the cutting tool <NUM> comprises a coolant supply part <NUM>.

As shown in <FIG> and <FIG>, a plate member <NUM> has a body <NUM> and a cutting insert <NUM>. The body <NUM> has a curved plate shape. As shown in <FIG>, the body <NUM> has an outer circumferential surface 21a serving as an outer side surface, an inner circumferential surface 21b and end surfaces 21c, 21d. The outer circumferential surface 21a and the inner circumferential surface 21b are each curved in a substantially circular arc shape in a front view. The end surfaces 21c, 21d are planes which connect an end of the outer circumferential surface 21a and an end of the inner circumferential surface 21b.

As shown in <FIG>, an insert seat <NUM> is formed at an end of the body <NUM> in the leading end direction. The insert seat <NUM> is a notch formed at a corner of the body <NUM>. The insert seat <NUM> has a bottom surface <NUM> and a wall part <NUM> arranged on a base end side. The wall part <NUM> of the insert seat <NUM> is provided with a mounting hole <NUM>.

As shown in <FIG>, the cutting insert <NUM> has a leading end part <NUM> and a protrusion part <NUM>. The leading end part <NUM> has edge parts 221a, 221b in its edge. The edge part 221a is a cutting edge which cuts a workpiece so as to form a bottom of a groove. The edge part 221b is a cutting edge which cuts a workpiece so as to form a side of a groove. The protrusion part <NUM> is projected from one side surface of the leading end part <NUM>.

The cutting insert <NUM> is fixed to the insert seat <NUM> of the body <NUM>. More specifically, the protrusion part <NUM> of the cutting insert <NUM> is fitted into the mounting hole <NUM> and is then held by the body <NUM>, whereby the cutting insert <NUM> is fixed to the insert seat <NUM>. Part of an outer side surface of the leading end part <NUM> of the cutting insert <NUM> comes into contact with the bottom surface <NUM> of the insert seat <NUM> and is thereby supported. As shown in <FIG>, the cutting insert <NUM> is fixed to the insert seat <NUM> while the edge parts 221a, 221b are being exposed.

As shown in <FIG>, the support member <NUM> is a member which supports the plate member <NUM> so as to allow the cutting insert <NUM> to be projected closer to a leading end than an end of the support member <NUM>. An upper surface of the support member <NUM> is provided with a plurality of threaded holes (not shown) into which screws <NUM> of the fixing member <NUM>, which is described below, are screwed.

Further, as shown in <FIG> and <FIG>, the support member <NUM> has a first wall surface <NUM>, a second wall surface <NUM> and a third wall surface <NUM>. The first wall surface <NUM>, the second wall surface <NUM> and the third wall surface <NUM> are all planes which come into contact with the body <NUM> of the plate member <NUM>. More specifically, as shown in <FIG>, the first wall surface <NUM> comes into contact with part of the outer circumferential surface 21a of the body <NUM>. The second wall surface <NUM> is arranged so as to form an obtuse angle with the first wall surface <NUM>, and comes into contact with another part of the outer circumferential surface 21a of the body <NUM>. The third wall surface <NUM> comes into contact with the end surface 21c of the body <NUM> and supports the plate member <NUM> such that the plate member <NUM> does not fall. The plate member <NUM> is supported by the first wall surface <NUM>, the second wall surface <NUM> and the third wall surface <NUM>, whereby, unless the support member <NUM> is fixed by the fixing member <NUM> described below, the plate member <NUM> is configured so as to be slidable in the leading end direction with respect to the support member <NUM>.

A notch <NUM> is arranged at a leading end part of the first wall surface <NUM>. The notch <NUM> has a shape like an obliquely cut cylinder. As shown in <FIG>, the notch <NUM> is a non-contact surface with respect to the outer circumferential surface 21a of the plate member <NUM> supported by the support member <NUM>. In other words, the notch <NUM> forms a gap 34a with respect to the outer circumferential surface 21a of the plate member <NUM> supported by the support member <NUM>. The notch <NUM> reaches the end surface 3a, which is located in the leading end direction, of the support member <NUM> and also notches part of the end surface 3a.

The coolant supply part <NUM> supplies coolant to the edge parts 221a, 221b of the cutting insert <NUM> and thereby cools the edge parts 221a, 221b. As shown in <FIG> and <FIG>, the coolant supply part <NUM> has a flow path <NUM> and an ejection port <NUM>. The flow path <NUM> is a hole formed so as to extend from an outer side surface of the support member <NUM> toward the inside. The ejection port <NUM>, serving as an outlet of the flow path <NUM>, is provided so as to be open in the notch <NUM>. The ejection port <NUM> is directed toward the leading end side. In other words, the ejection port <NUM> is provided so as to be open such that the ejection port <NUM> ejects coolant which flows through the flow path <NUM> toward the leading end side.

It should be noted that the ejection port <NUM> is preferably provided so as to be open toward the plate member <NUM>. More specifically, the ejection port <NUM> is preferably provided so as to be open such that a normal of the ejection port <NUM> is directed toward the plate member <NUM>. Further, the coolant which is made to flow through the flow path <NUM> may be either liquid or gas, as long as it is fluid which is to be used to cool the edge parts 221a, 221b. The gas includes a mist gas.

The fixing member <NUM> is a member which fixes the plate member <NUM>, which is slidable as described above, to the support member <NUM>. As shown in <FIG>, the fixing member <NUM> comprises a pressure member <NUM> and the plurality of screws <NUM>.

As shown in <FIG>, the pressure member <NUM> has a contact surface 51a as a plane thereof. The pressure member <NUM> is further provided with a plurality of through holes (not shown) which penetrate an upper surface thereof and a lower surface thereof. The pressure member <NUM> is arranged, above the support member <NUM>, such that the contact surface 51a comes into surface contact with the end surface 21d of the plate member <NUM>. The screws <NUM> are inserted through the through holes of the pressure member <NUM> and are also screwed into the threaded holes formed in the upper surface of the support member <NUM>. As a result, the pressure member <NUM> is fastened to the support member <NUM>.

When a fastening force of the screw <NUM> is increased, a head part of the screw <NUM> presses the pressure member <NUM> downward. The pressure member <NUM> presses the end surface 21d of the plate member <NUM> downward, via the contact surface 51a. As a result, the plate member <NUM> is sandwiched by the contact surface 51a and the third wall surface <NUM>, and the outer circumferential surface 21a is supported by the first wall surface <NUM> and the second wall surface <NUM>, whereby the plate member <NUM> is fixed to the support member <NUM>.

Next, cutting by way of the cutting tool <NUM> will be described with reference to <FIG> shows a cross-section of a workpiece <NUM> which is cut by the cutting tool <NUM>. For ease of understanding of the description, <FIG> shows the cross-section of the workpiece <NUM> in a see-through manner.

The workpiece <NUM> cut by the cutting tool <NUM> is rotated in a direction indicated by an arrow R around an axis <NUM> which is distant from the plate member <NUM>. When the cutting insert <NUM> of the cutting tool <NUM> is caused to abut against an end surface <NUM> of the workpiece <NUM>, the edge part 221a of the cutting insert <NUM> cuts the end surface <NUM>. When the cutting insert <NUM> is further caused to abut against the end surface <NUM>, the cutting insert <NUM> enters the workpiece <NUM> through the cut. As a result, an annular groove <NUM> is formed in the end surface <NUM> of the workpiece <NUM>.

At this time, the gap 34a (see <FIG>), which is formed by the notch <NUM> of the support member <NUM>, is opened toward the workpiece <NUM>. Therefore, the ejection port <NUM> arranged in the gap 34a ejects coolant C toward the workpiece <NUM>, as indicated by an arrow E.

Part of the coolant C ejected from the ejection port <NUM> is directed toward the plate member <NUM> as well. When the coolant C adheres to the outer circumferential surface 21a of the plate member <NUM>, the coolant C moves along the outer circumferential surface 21a and then flows into the groove <NUM>. The coolant C reaches the edge parts 221a, 221b of the cutting insert <NUM> which are arranged inside the groove <NUM>. Thus, when the machining proceeds so that the entireties of the edge parts 221a, 221b of the cutting insert <NUM> are arranged inside the groove <NUM>, the edge parts 221a, 221b can be cooled in a reliable manner.

In other words, in the cutting tool <NUM>, it does not mean that the coolant C in its entirety is ejected from the ejection port <NUM> directly toward the edge parts 221a, 221b; rather, the coolant C is intentionally ejected toward the plate member <NUM> as well. As a result, the coolant C can be supplied reliably to the edge parts 221a, 221b arranged inside the narrow groove <NUM> without being obstructed by the workpiece <NUM>.

Further, the coolant C adhering to the plate member <NUM> cools the plate member <NUM> and the cutting insert <NUM> fixed to the plate member <NUM>. The plate member <NUM> is cooled, as described above, whereby the edge parts 221a, 221b can be cooled indirectly. The wear of the edge parts 221a, 221b is suppressed by means of cooling, leading to the extension of the lives thereof.

Further, the coolant supply part <NUM> has, inside the support member <NUM>, the flow path <NUM> through which the coolant C passes. The ejection port <NUM> is provided so as to be open in the non-contact surface <NUM>. With this configuration, the ejection port <NUM> can be arranged in the vicinity of the plate member <NUM> without using a hose, etc. Consequently, the coolant C ejected from the ejection port <NUM> can be caused to reliably move along the plate member <NUM> and thereby be supplied reliably to the edge parts 221a, 221b.

Further, the notch <NUM>, being a non-contact surface, is formed by notching the end of the support member <NUM>. This configuration can suppress the adhesion to the ejection port <NUM> of chips produced during the cutting of the workpiece <NUM>. Consequently, the coolant C ejected from the ejection port <NUM> can be caused to reliably move along the plate member <NUM> and thereby be supplied reliably to the edge parts 221a, 221b.

The present invention has been described above, taking an embodiment of the invention as an example. However, the present invention is not limited to the above embodiment. In other words, various modifications may be made to the present invention without departing from the essential technical idea of the present invention to the effect that "a plate member is used so as to supply fluid to edge parts.

Claim 1:
A cutting tool (<NUM>) which is configured to form a groove in a workpiece, the cutting tool (<NUM>) comprising:
a plate member (<NUM>) which is provided, at a leading end thereof, with edge parts (221a, 221b);
a support member (<NUM>) which supports the plate member (<NUM>) so as to cause the edge parts (221a, 221b) to be projected; and
a fluid supply part (<NUM>) which has an ejection port (<NUM>) and which is configured to eject, from the ejection port (<NUM>), fluid that can cool the edge parts (221a, 221b), wherein:
the support member (<NUM>) has a non-contact surface (<NUM>) which forms a gap (34a) with respect to an outer side surface of the plate member (<NUM>);
the gap (34a) is opened toward a side where the edge parts (221a, 221b) are provided; and
the ejection port (<NUM>) is arranged in the gap (34a), and the ejection port (<NUM>) is configured so that the fluid can be ejected toward the plate member (<NUM>),
wherein:
the fluid supply part (<NUM>) has, inside the support member (<NUM>), a flow path (<NUM>) through which the fluid passes; and
the ejection port (<NUM>) is opened in the non-contact surface (<NUM>), and
characterized in that the non-contact surface (<NUM>) is a notch formed at a leading end surface of the support member, whereby the notch (<NUM>) reaches the end surface (3a), which is located in the leading end direction, of the support member (<NUM>) and also notches part of the end surface (3a),
wherein the plate member (<NUM>) is curved so as to be projected toward the support member (<NUM>).