阅读说明：本技术 加工工具 (Machining tool ) 是由 冈秀树 畑山忠友 小出雅也 于 2019-07-19 设计创作，主要内容包括：加工工具(10)对具有开口(12a)的阀座材料(12)的内周实施切削加工来形成第1退避面(14)、阀座面(16)、第2退避面(18)。加工工具(10)具有工具主体(40)、多个切削刀具(42、44、46)、套筒(48)和凸轮(50),其中,所述工具主体(40)被驱动以绕其轴线(a)旋转；所述多个切削刀具(42、44、46)与工具主体(40)一起旋转；所述套筒(48)以能沿轴线(a)进退的方式被安装于工具主体(40)；所述凸轮(50)抵接于套筒(48)的基端面(70d)且使套筒(48)进退。多个切削刀具(42、44、46)的至少1个被安装于套筒(48)。(A machining tool (10) performs cutting on the inner periphery of a valve seat material (12) having an opening (12a) to form a 1 st receding surface (14), a valve seat surface (16), and a 2 nd receding surface (18). A machining tool (10) having a tool body (40), a plurality of cutting inserts (42, 44, 46), a sleeve (48) and a cam (50), wherein the tool body (40) is driven to rotate about its axis (a); the plurality of cutting inserts (42, 44, 46) rotating with the tool body (40); the sleeve (48) is attached to the tool body (40) so as to be able to advance and retreat along an axis (a); the cam (50) abuts against a base end surface (70d) of the sleeve (48) and advances and retreats the sleeve (48). At least 1 of the plurality of cutting tools (42, 44, 46) is mounted to the sleeve (48).)

1. A machining tool (10) for forming a plurality of machined surfaces (14, 16, 18) by cutting the inner periphery of a workpiece having an opening (12a),

it is characterized in that the preparation method is characterized in that,

having a tool body (40), a plurality of cutting inserts (42, 44, 46), a sleeve (48) and a cam (50), wherein,

the tool body is driven to rotate about its axis (a);

the plurality of cutting inserts rotating with the tool body;

the sleeve is attached to the tool body so as to be able to advance and retreat along the axis;

the cam abuts against a base end surface (70d) of the sleeve to advance and retreat the sleeve,

at least 1 of the plurality of cutting tools is mounted to the sleeve.

2. The machine tool of claim 1,

the cam has an arc surface (50c) along the outer periphery of the arc and a notch surface (50a) formed by cutting off a part of the arc, and can selectively make the arc surface and the notch surface contact with the base end surface of the sleeve by rotating with the center of the arc as a rotation center,

when the arc surface is abutted against the base end surface, the sleeve advances,

when the notch surface abuts against the base end surface, the sleeve retreats.

3. The machine tool of claim 2,

further comprises a cam biasing member (52) for elastically biasing the sleeve in a backward direction,

the sleeve is advanced against the elastic force of the cam urging member by the circular arc surface abutting against the base end surface,

the sleeve is retracted by the elastic force of the cam biasing member by the notch surface abutting against the base end surface.

4. A machine tool of claim 2 or 3,

and a rod (54) and a cylinder chamber (98), wherein,

the lever rotates the cam by advancing and retracting along the axis inside the tool body;

the cylinder chamber is provided inside the tool body and can be supplied with a fluid,

the rod has a piston (54a) movable in the cylinder chamber along the axis,

the piston is displaced by the pressure of the fluid of the cylinder chamber, thereby advancing and retreating the rod.

5. The machine tool of claim 4,

the rod advances and retreats between an advancing position at the forward-and-retreating direction tip end and a retreating position at the forward-and-retreating direction base end,

the piston is elastically urged toward the front end side of the cylinder chamber by a piston urging member (56),

the cylinder chamber communicates with a supply path (118) provided to the rod,

the rod is advanced to the advanced position by an elastic force of the piston urging member before the fluid is supplied to the cylinder chamber,

the fluid is supplied to the cylinder chamber through the supply passage, and the pressure of the fluid in the cylinder chamber is increased, and at this time, the rod is retracted against the elastic force of the piston biasing member.

6. The machine tool of claim 5,

a communication path (114) and a tip side flow path (112) are provided in the rod, wherein,

the communication path communicates with the cylinder chamber when the rod is retreated from the advanced position to a communication position, and is blocked from the cylinder chamber when the rod is positioned on a tip end side from the communication position,

the tip end side flow passage communicates with the communication path and extends from the communication path to the tip end side,

the fluid is supplied to the cylinder chamber through the supply passage, and the rod is retracted to the communication position, whereby the fluid is supplied to the tip end side passage when the cylinder chamber is communicated with the communication passage.

7. The machine tool of claim 6,

the rod is provided with the communication path at a position closer to the distal end side than the piston, and a bulging portion (54b) bulging from the outer peripheral surface of the rod is provided at a position closer to the distal end side than the communication path,

the cam is provided with a recess (50b) into which the bulge can be inserted,

the lever is advanced to the advanced position while the bulging portion is brought into contact with the inner surface of the recess, and the cam is rotated so that the arc surface is brought into contact with the base end surface of the sleeve, and the lever is retracted to the retracted position while the bulging portion is brought into contact with the inner surface of the recess, and the cam is rotated so that the notch surface is brought into contact with the base end surface of the sleeve.

8. The machine tool of claim 6 or 7,

the distance from the forward position to the position where the notch surface of the cam abuts against the base end surface of the sleeve is shorter than the distance from the forward position to the communication position.

9. A machine tool of any of claims 4 to 8,

the fluid is a coolant supplied to a machining point of the workpiece.

10. The machine tool of any of claims 4 to 9,

the cylinder device further comprises a fluid sensor (59) for detecting at least one of the flow rate and the pressure of the fluid supplied to the cylinder chamber.

11. The machine tool of any of claims 1 to 10,

the sleeve is slidably disposed in a groove (72) formed along the axis in the tool body,

the groove has a 1 st inner wall surface (72a) and a 2 nd inner wall surface (72b), wherein the 1 st inner wall surface abuts against a rear end surface (78) in a rotation direction of the sleeve that rotates together with the tool body; the 2 nd inner wall surface abuts against an end surface (80) of the sleeve on the axial side,

the tool body is provided with a pressing member (82) which presses the sleeve from the front in the rotation direction of the sleeve in a direction inclined with respect to the 1 st inner wall surface and the 2 nd inner wall surface.

12. The machine tool of any of claims 1 to 11,

the plurality of processing surfaces are a valve seat surface (16) of a cylinder head (22) and a 1 st retreating surface (14) and a 2 nd retreating surface (18) which are respectively arranged at two end sides of the valve seat surface in the axial direction,

the plurality of cutting tools include a 1 st cutting tool (42) forming the 1 st relief surface, a 2 nd cutting tool (44) forming the 2 nd relief surface, and a 3 rd cutting tool (46) forming the valve seat surface,

the 1 st cutting insert and the 2 nd cutting insert are directly attached to a tip end portion of the tool body,

the 3 rd cutting tool is attached to a distal end portion of the sleeve.

13. The machine tool of any of claims 1 to 11,

the plurality of processing surfaces are a valve seat surface of the cylinder head and a 1 st retreating surface and a 2 nd retreating surface which are respectively arranged at two end sides of the valve seat surface in the axial direction,

the plurality of cutting tools include a 1 st cutting tool forming the 1 st relief surface, a 2 nd cutting tool forming the 2 nd relief surface, and a 3 rd cutting tool forming the valve seat surface,

the 1 st cutting tool and the 2 nd cutting tool are attached to a tip end portion of the sleeve,

the 3 rd cutting insert is directly attached to the tip end portion of the tool body.

14. The machine tool of any of claims 1 to 13,

a reamer (58) for machining a valve guide hole is fixed to the tip of the tool body.

Technical Field

The present invention relates to a machining tool for forming a plurality of machined surfaces by performing cutting machining on an inner periphery of an opening of a workpiece.

Background

For example, japanese patent laid-open publication No. 3020179 discloses a machining tool in which a plurality of machined surfaces having different inclination angles with respect to the axial direction are formed by performing cutting on the inner periphery of an opening. In this machining tool, a plurality of cutting tools (cutting tools) are provided on a distal end portion of a tool body that is rotationally driven around an axis. The cutting tool is rotated together with the tool body and simultaneously brought into contact with a portion to be machined of a workpiece to perform cutting, thereby simultaneously forming a plurality of machined surfaces.

Disclosure of Invention

In the above-described cutting process, since the machining allowance for cutting each of the plurality of machining surfaces is different, the machining tool having the machining surface with a large machining allowance may be more likely to wear than the other cutting tools in the machining tool in which the plurality of cutting tools are simultaneously brought into contact with the workpiece. In particular, when a cutting tool for machining a machining surface that requires higher precision than other machining surfaces is easily worn, if the cutting tool is not frequently ground and replaced, the machining surface with the required precision cannot be obtained. Therefore, it is difficult to achieve both high-precision machining and efficient machining. Further, in order to simultaneously bring the plurality of cutting tools into contact with the workpiece, it is necessary to accurately adjust the positional relationship of each of the plurality of cutting tools, and the work of reattaching the cutting tools after polishing and replacement is liable to become complicated. There is also a concern that efficient processing will be affected thereby.

The present invention has been made to solve the above-described problems, and provides a machining tool that can easily perform high-precision and high-efficiency cutting.

One aspect of the present invention is a machining tool for forming a plurality of machined surfaces by performing cutting machining on an inner periphery of a workpiece having an opening, the machining tool including a tool body, a plurality of cutting tools, a sleeve (Cartridge), and a cam, wherein the tool body is driven to rotate about an axis thereof; the plurality of cutting inserts rotating with the tool body; the sleeve is attached to the tool body so as to be able to advance and retreat along the axis; the cam abuts on a proximal end surface of the sleeve to advance and retract the sleeve, and at least 1 of the plurality of cutting tools is attached to the sleeve.

In the present invention, the cutting tool attached to the sleeve can be advanced and retracted along the axis. Accordingly, the cutting insert attached to the sleeve is brought into contact with the portion to be machined at a different timing from the cutting insert directly attached to the tool body, so that a plurality of machined surfaces can be machined at different timings.

Therefore, for example, a machined surface (target machined surface) which is required to be formed with higher accuracy than the other machined surface can be machined after the other machined surface. Accordingly, the machining allowance at the machining surface to be machined can be reduced, and the abrasion of the cutting tool at the machining surface to be machined can be effectively suppressed. As a result, the target machining surface can be machined with high precision without increasing the frequency of grinding and changing the cutting tool.

Further, as described above, since the sleeve is only required to be advanced and retracted when a plurality of machining surfaces are machined at different timings, it is not necessary to perform tool replacement using a tool changer (tool changer) or the like, and accordingly, cutting can be efficiently performed.

Accordingly, the machining tool of the present invention can easily perform high-precision and high-efficiency cutting.

In addition, in this machining tool, since the sleeve is provided to be able to advance and retreat along the axis, for example, the outer dimension in the direction orthogonal to the axis can be reduced as compared with a case where the sleeve is provided to be able to advance and retreat in a direction inclined with respect to the axis. Therefore, for example, it is also easy to arrange the machining tools to realize multi-axis machining and the like in order to perform cutting on the inner peripheries of the plurality of openings at a time.

Drawings

Fig. 1 is a schematic explanatory view of a distal end surface of a machining tool according to an embodiment of the present invention.

Fig. 2 is a main part sectional view of II-II of fig. 1 in a state where the lever is advanced to the advanced position. Fig. 3 is a main part sectional view in a state where the lever of fig. 2 is retracted to a retracted position.

Fig. 4A to 4C are explanatory diagrams illustrating a relationship between a distance La until the lever retreats from the advanced position until the notch surface of the cam abuts against the sleeve and a distance Lb until the lever retreats from the advanced position until the lever reaches the communication position.

Fig. 5 is a schematic partial cross-sectional view of a valve seat material and a cylinder head body before cutting.

Fig. 6 is a schematic partial sectional view of the cylinder head after the valve seat material of fig. 5 is subjected to cutting.

Fig. 7 is a schematic explanatory view for explaining a case where the relief surface is machined in the valve seat material of fig. 5 by using the 1 st cutting tool and the 2 nd cutting tool.

Fig. 8 is a schematic explanatory view for explaining a case where the valve seat surface is machined by the 3 rd cutting tool with respect to the valve seat material of fig. 7.

Detailed Description

The machining tool according to the present invention will be described in detail with reference to the drawings, taking preferred embodiments as examples. In the following drawings, the same reference numerals are given to the same or similar components that achieve the same functions and effects, and redundant description may be omitted.

An example will be described below in which the processing tool 10 according to the present embodiment shown in fig. 1, 2, 3, 4A, 4B, and 4C is applied to form the 1 st relief surface 14, the seat surface 16, and the 2 nd relief surface 18 shown in fig. 6 as a plurality of processing surfaces by using the seat material 12 shown in fig. 5 as a workpiece and performing cutting processing on the inner periphery of the opening 12a of the seat material 12. The 1 st receding surface 14, the valve seat surface 16, and the 2 nd receding surface 18 are inclined surfaces having different inclination angles with respect to the axial direction of the opening 12 a. As shown in fig. 5, the valve seat material 12 is press-fitted or joined to the cylinder head body 20, and as described above, the valve seat 24 of the cylinder head 22 shown in fig. 6 is formed by cutting.

However, the object to which the cutting process can be performed by the machining tool 10 is not limited to the valve seat material 12. The plurality of processing surfaces that can be formed by the processing tool 10 are not limited to the 1 st receding surface 14, the valve seat surface 16, and the 2 nd receding surface 18 described above. The machining tool 10 is preferably applied to a case where a plurality of machined surfaces are formed by performing cutting on the inner periphery of an opening of a workpiece. Examples thereof include a case where a rough-bored machined surface and a finish-bored machined surface are formed on the inner periphery of the opening of the workpiece, and a case where a bored machined surface and a chamfered machined surface are formed on the inner periphery of the opening of the workpiece.

First, the cylinder head 22 will be briefly described with reference to fig. 6. The cylinder head 22 includes an annular valve seat 24 formed of a sintered body of an iron-based material such as a steel material, and a cylinder head body 20 formed of an aluminum-based material such as pure aluminum or an aluminum alloy, for example. Further, the valve seat 24 may further contain a high-conductivity material such as a copper-based material.

The cylinder head body 20 is formed with ports 26 having one end side opened to respective combustion chambers, not shown. In the present embodiment, the annular valve seat 24 is inserted into the opening peripheral edge portion on one end side (arrow X1 side) of the port 26, whereby the valve seat 24 is fitted to the opening peripheral edge portion.

On the inner periphery of the valve seat 24, a 1 st receding surface 14, a valve seat surface 16, and a 2 nd receding surface 18, which are different from each other in surface direction, are arranged in this order from one end side (arrow X1 side) to the other end side (arrow X2 side) in the axial direction. The 1 st receding surface 14, the valve seat surface 16, and the 2 nd receding surface 18 are inclined in the direction of the diameter expansion opening toward the combustion chamber side (arrow X1 side), respectively. Examples of the inclination angle of each surface of the valve seat 24 with respect to the axial direction include 60 ° for the 1 st receding surface 14, 45 ° for the valve seat surface 16, and 30 ° for the 2 nd receding surface 18, but are not particularly limited thereto.

The port 26 can be opened and closed by a valve, not shown, being seated on or separated from the seat surface 16 in the inner circumferential surface of the valve seat 24. Therefore, in order to achieve high quality of the cylinder head 22, the valve is brought into contact with the valve seat surface 16 without a gap, and therefore, it is necessary to precisely machine the inner peripheral surface of the valve seat 24, particularly the roundness, surface roughness, and the like of the valve seat surface 16.

Next, referring to fig. 5, the valve seat material 12 before being cut into the valve seat 24, in other words, the valve seat material 12 on which the 1 st receding surface 14, the valve seat surface 16, and the 2 nd receding surface 18 are not formed, will be described. The valve seat material 12 is annular and is press-fitted into the cylinder head body 20. The valve seat member 12 has, for example, an orthogonal end face 28 disposed on one end side in the axial direction (arrow X1 side), an axial face 30 disposed on the other end side in the axial direction, and a tapered face 32 disposed between the orthogonal end face 28 and the axial face 30 on the inner periphery thereof. The orthogonal end face 28 is orthogonal to the axial direction. The axial face 30 is formed coplanar with the inner circumferential face of the port 26. The tapered surface 32 is tapered so as to be inclined toward one end side (arrow X1 side) in the axial direction in a direction of the diameter-enlarged opening.

Next, the machining tool 10 will be described with reference to fig. 1 to 4C. The machining tool 10 performs cutting on the inner periphery of the opening 12a of the valve seat material 12 shown in fig. 5 to form a 1 st receding surface 14, a valve seat surface 16, and a 2 nd receding surface 18 shown in fig. 6. In the present embodiment, the machining tool 10 is a composite machining tool that can perform reaming of a valve guide hole (not shown) in addition to cutting of the valve seat member 12. The valve guide hole is provided in the cylinder head body 20, and the shaft portion (not shown) of the valve described above can be inserted therethrough.

Specifically, the machining tool 10 mainly includes a tool body 40, a 1 st cutting tool 42, a 2 nd cutting tool 44 (see fig. 1), a 3 rd cutting tool 46, a sleeve 48, a cam 50 shown in fig. 2 to 4C, a cam biasing member 52, a rod 54, a piston biasing member 56, a reamer 58, and a fluid sensor 59 shown in fig. 2 and 3.

As shown in fig. 2 and 3, the tool body 40 is integrally formed of a 1 st member 40a, a 2 nd member 40b, and a 3 rd member 40 c. The 1 st member 40a, the 2 nd member 40b, and the 3 rd member 40c are sequentially connected from the distal end side (arrow Y1 side) to the proximal end side (arrow Y2 side) of the tool body 40. The 1 st member 40a is a substantially cylindrical shape having a stepped shape with a smaller diameter on the distal end side than on the proximal end side. Further, a large diameter portion 40aL is provided on the base end side of the 1 st member 40 a. The base end side of the 1 st member 40a and the tip end side of the 2 nd member 40b are fixed by bolting or the like through the outer periphery side of the large diameter portion 40 aL.

A small diameter portion 40bS having a smaller diameter than the distal end side is provided on the proximal end side of the 2 nd member 40 b. The distal end side of the 3 rd member 40c is fitted to the outside of the small diameter portion 40bS, whereby the proximal end side of the 2 nd member 40b and the distal end side of the 3 rd member 40c are fixed. The tool body 40 is rotationally driven about the axis a by fixing the base end side of the 3 rd member 40c to a rotary spindle of a rotational driving mechanism provided in a not-shown working machine. The tool body 40 is driven to advance and retract along the axis a by a tool body driving mechanism provided in the working machine.

The 1 st cutting insert 42 has a cutting edge 42a for machining the 1 st relief surface 14 (see fig. 6), and is detachably attached to the 1 st member 40a of the tool body 40 via a shank 42 b. Specifically, as shown in fig. 1, the 1 st cutting insert 42 is directly fixed to the tool body 40 by sandwiching the shank 42b between an inner wall 60a of a housing groove 60 provided in the 1 st member 40a along the axis a and a fastening member 62 provided in front of the inner wall 60a in the rotation direction (hereinafter, also simply referred to as the rotation direction) of the tool body 40.

The tightening member 62 can apply a tightening force by screwing a screw 64 into a screw hole provided to extend in the radial direction of the tool body 40, and pressing the shank 42b against the inner wall 60a of the accommodating groove 60 from the front in the rotational direction. In the fastening member 62, the fastening to the shank 42b can be loosened by loosening the screwing of the screw hole and the screw 64, and thereby the shank 42b can be moved in and out between the inner wall 60a of the housing groove 60 and the fastening member 62.

The 2 nd cutting insert 44 has a cutting edge 44a (see fig. 7) for machining the 2 nd clearance surface 18 (see fig. 6), and is detachably attached to the 1 st member 40a of the tool body 40 via a shank 44 b. The 2 nd cutting insert 44 is also directly fixed to the tool body 40 by the fastening member 62, similarly to the 1 st cutting insert 42.

The 3 rd cutting tool 46 has a cutting edge 46a for processing the valve seat surface 16 (see fig. 6), and is detachably attached to the sleeve 48 via a shank 46 b. Specifically, the 3 rd cutting tool 46 is fixed to the sleeve 48 by sandwiching the shank 46b between the inner wall 66a of the housing groove 66 provided in the sleeve 48 along the axis a and the fastening member 62 provided in the front of the inner wall 66a in the rotational direction.

The sleeve 48 is attached to the 1 st member 40a of the tool body 40 so as to be able to advance and retreat along the axis a, and is rotationally driven together with the tool body 40. In the following description, the side toward the distal end of the tool body 40 (arrow Y1 side) is referred to as the forward direction, and the side toward the proximal end of the tool body 40 (arrow Y2 side) is referred to as the backward direction.

As shown in fig. 2 and 3, the sleeve 48 is formed integrally with a sleeve body 68 and a push rod 70. The sleeve body 68 is disposed on the 1 st member 40a of the tool body 40 so as to be slidable within a groove 72 formed along the axis a. The sleeve body 68 has a cylindrical body 74 and an extension 76 extending from a portion on the axial line a side of the cylindrical body 74 (the center side in the radial direction of the tool body 40) toward the tip end side (arrow Y1 side). A receiving groove 66 for receiving the shank 46b of the 3 rd cutting tool 46 is provided in the entire axial direction of the extension portion 76 and a part of the distal end side of the cylindrical body 74.

As shown in fig. 1, the tubular body 74 is formed into a substantially rectangular shape when viewed from the distal end side of the axis a, and has a pressure receiving surface 74a formed by cutting a corner portion located on the front side in the rotation direction and located on the outer side in the radial direction of the tool body 40. An end surface 78 of the cylinder 74 and the extension 76 at the rear in the rotational direction is formed to be coplanar with each other, and an end surface 80 at the axis a side is formed to be coplanar with each other. These end faces 78, 80 are orthogonal to each other. The pressure receiving surface 74a is inclined with respect to the end surfaces 78, 80. At this time, the pressure receiving surface 74a is preferably provided to be inclined at, for example, substantially 45 ° with respect to the end surfaces 78, 80, respectively.

Inside the groove 72, the 1 st inner wall surface 72a of the groove 72 abuts against the end surface 78 of the sleeve body 68, and the 2 nd inner wall surface 72b of the groove 72 abuts against the end surface 80. Since the 1 st inner wall surface 72a extends along the end surface 78 and the 2 nd inner wall surface 72b extends along the end surface 80, the 1 st and 2 nd inner wall surfaces 72a, 72b are orthogonal to each other.

A plate spring 82 (pressing member) attached to the 1 st member 40a of the tool body 40 by bolting or the like abuts against the pressure receiving surface 74a from the front in the rotational direction. The plate spring 82 presses the sleeve main body 68 from the front in the rotation direction of the sleeve main body 68 in a direction inclined with respect to the 1 st inner wall surface 72a and the 2 nd inner wall surface 72b of the groove 72.

As shown in fig. 2 and 3, a fitting hole 84 is provided along the axis a on the proximal end side of the cylindrical body 74, and the small diameter portion 70a on the distal end side of the push rod 70 is fitted into the fitting hole 84. A shaft portion 70b having a larger diameter than the small diameter portion 70a is provided on the base end side of the small diameter portion 70a of the push rod 70, and a flange portion 70c is provided on the base end side of the shaft portion 70 b. A through hole 86 is provided along the axis a in a portion of the large diameter portion 40aL of the tool body 40 facing the groove 72. By inserting the shaft portion 70b of the push rod 70 into the through hole 86 so as to be movable forward and backward, most of the push rod 70 except the tip end side is inserted into a push rod chamber 88 formed inside the tool body 40 (the 1 st member 40a and the 2 nd member 40 b).

The through hole 86 has an inner diameter slightly larger than the outer diameter of the shaft portion 70b of the push rod 70 and smaller than the inner diameter of the push rod chamber 88. Accordingly, a step surface 90 is formed between the push rod chamber 88 and the through hole 86.

The diameter of the flange portion 70c of the push rod 70 is slightly less than the inner diameter of the push rod chamber 88 such that the flange portion 70c of the push rod 70 is slidable within the push rod chamber 88. A cam biasing member 52 made of an elastic body such as a spring is provided between the flange portion 70c and the step surface 90. The cam biasing member 52 is elastically biased in a direction to separate the flange portion 70c from the step surface 90, in other words, in a direction to retreat the sleeve 48.

In the tool body 40 (the 2 nd and 3 rd members 40b and 40c), a cam chamber 92 is provided in communication with the base end side of the push rod chamber 88, a rod chamber 94 is provided in communication with the axis a side of the cam chamber 92 (the center side in the radial direction of the tool body 40), a cylinder chamber 98 is provided in communication with the rod chamber 94 on the base end side (arrow Y2 side) of the cam chamber 92, and a storage chamber 100 is provided in communication with the base end side of the cylinder chamber 98.

The cam chamber 92 is provided with a cam 50 that abuts the base end surface 70d of the push rod 70. The rod chamber 94 is provided with a rod 54 that can advance and retreat along the axis a. In the cylinder chamber 98, a piston 54a provided to the rod 54 is provided so as to be able to advance and retreat along the axis a. In the storage chamber 100, a piston biasing member 56 made of an elastic body such as a spring is provided to elastically bias the piston 54a toward the distal end side of the cylinder chamber 98.

The cam 50 abuts on the proximal end surface 70d of the push rod 70, thereby advancing and retreating the sleeve 48. Specifically, the cam 50 is substantially circular and has a notch surface 50a formed by cutting out a part of an arc, a concave portion 50b recessed toward the center side of the circle, and an arc surface 50c provided between the notch surface 50a and the concave portion 50 b. A projection 54b projecting in an annular shape from the outer peripheral surface of the rod 54 on the distal end side can be inserted into the recess 50 b.

The cam 50 is rotationally driven around the center of the circle (arc) by advancing and retreating the lever 54 while causing the bulging portion 54b to enter the recess 50 b. Specifically, the rotation axis of the cam 50 passing through the rotation center described above intersects with the axis a, and is preferably orthogonal thereto. Further, by advancing the lever 54 while the bulging portion 54b is brought into contact with the inner surface of the recess 50b, the cam 50 rotates so that the arc surface 50c is brought into contact with the base end surface 70d of the sleeve 48 (the push rod 70) as shown in fig. 2.

On the other hand, by retracting the rod 54 while the bulging portion 54b is in contact with the inner surface of the recess 50b, the cam 50 rotates so that the notch surface 50a is in contact with the base end surface 70d of the sleeve 48 as shown in fig. 3. Accordingly, the arcuate surface 50c and the notched surface 50a can be selectively brought into contact with the base end surface 70d of the sleeve 48.

As shown in fig. 4A to 4C, the radius r of the arc surface 50C is longer than the length L of a perpendicular line from the center of the circle to the notch surface 50 a. Therefore, as shown in fig. 4A, compared to the case where the notch surface 50a is brought into contact with the base end surface 70d, by bringing the arcuate surface 50c into contact with the base end surface 70d, the sleeve 48 can be advanced by an amount corresponding to the difference between the radius r and the length L of the perpendicular line against the spring force of the cam biasing member 52. In this way, in a state where the sleeve 48 is advanced, as shown in fig. 2, for example, the cutting edge 46a of the 3 rd cutting tool 46 is disposed on the tip side of the cutting edge 42a of the 1 st cutting tool 42 and the cutting edge 44a of the 2 nd cutting tool 44. Accordingly, the 3 rd cutting tool 46 can be brought into contact with only the inner periphery of the valve seat member 12 to perform cutting.

On the other hand, as shown in fig. 4B and 4C, compared to the case where the arcuate surface 50C is brought into contact with the base end surface 70d, by bringing the notch surface 50a into contact with the base end surface 70d, the sleeve 48 can be retracted by the spring force of the cam biasing member 52 by an amount corresponding to the difference between the radius r and the length L of the perpendicular line. In the state where the sleeve 48 is retracted in this way, as shown in fig. 3, for example, the cutting edge 42a of the 1 st cutting tool 42 and the cutting edge 44a of the 2 nd cutting tool 44 are disposed on the tip end side of the cutting edge 46a of the 3 rd cutting tool 46. Accordingly, the cutting process can be performed by bringing only the 1 st cutting tool 42 and the 2 nd cutting tool 44 into contact with the inner periphery of the valve seat member 12.

As shown in fig. 2 and 3, on the 2 nd member 40b of the tool main body 40, a 1 st partition 102 extending in the radial direction between the cam chamber 92 and the cylinder chamber 98 is provided. An inner peripheral surface 102a of the 1 st partition 102 facing the rod chamber 94 is slidable along an outer peripheral surface of the 1 st sliding portion 54c provided at a middle stage in the extending direction of the rod 54. The 3 rd member 40c of the tool body 40 is provided with a 2 nd partition 104 extending along the axis a between the proximal end side (arrow Y2 side) of the lever chamber 94 and the storage chamber 100. An inner peripheral surface 104a of the 2 nd partition 104 facing the rod chamber 94 is slidable along an outer peripheral surface of the 2 nd sliding portion 54d provided on the base end side of the rod 54.

That is, the rod 54 can advance and retreat between the advance position at the tip in the advance and retreat direction shown in fig. 2 and 4A and the retreat position at the base end in the advance and retreat direction shown in fig. 3 and 4C while sliding the outer peripheral surfaces of the 1 st sliding portion 54C and the 2 nd sliding portion 54d and the inner peripheral surfaces 102a and 104A of the 1 st partition portion 102 and the 2 nd partition portion 104, respectively.

Specifically, the rod 54 is provided with a 1 st sliding portion 54c at a position spaced apart from a bulging portion 54b provided on the distal end side thereof by a predetermined distance toward the base end side, a stopper portion 54e having a larger diameter than the 1 st sliding portion 54c is provided at the base end of the 1 st sliding portion 54c, a piston 54a having a larger diameter than the stopper portion 54e is provided at the base end of the stopper portion 54e, and a 2 nd sliding portion 54d having a smaller diameter than the 1 st sliding portion 54c is provided at the base end of the piston 54 a.

A sealing member 106 for sealing between the inner peripheral surface 102a of the 1 st partition 102 and the outer peripheral surface of the 1 st sliding portion 54c is provided in an annular sealing groove formed in the outer peripheral surface on the tip end side of the 1 st sliding portion 54 c. A sealing member 108 for sealing between the inner peripheral surface 104a of the 2 nd partition 104 and the outer peripheral surface of the 2 nd sliding portion 54d is provided in an annular sealing groove formed in the outer peripheral surface of the 2 nd sliding portion 54d on the base end side. A seal member 110 for sealing the distal end side and the proximal end side of the piston 54a of the cylinder chamber 98 is provided in an annular seal groove formed in the outer peripheral surface of the piston 54 a.

Inside the rod 54, a tip end side flow passage 112, a plurality of communication passages 114, a blocking portion 116, and a supply passage 118 are provided. The tip-side flow passage 112 extends along the axis a on the tip side of the blocking portion 116 of the rod 54. Each communication path 114 extends in the radial direction of the rod 54 between the distal end side flow path 112 and the outer peripheral surface of the 1 st sliding portion 54 c. That is, an opening 114a on one end side in the extending direction of each communication path 114 (outside in the radial direction of the rod 54) is provided on the outer peripheral surface of the 1 st sliding portion 54 c. The blocking section 116 is interposed between the tip end side flow passage 112 and the supply passage 118, and blocks them so as not to communicate with each other.

The supply passage 118 supplies coolant (fluid) from a coolant supply mechanism provided in the working machine (not shown) through a 1 st cylindrical member 120 provided at the base end portion of the rod chamber 94. The supply path 118 includes an upstream portion 118a extending along the axis a, and a plurality of branch portions 118b branching from the upstream portion 118a and extending toward the outer peripheral surface of the stopper portion 54 e. That is, the downstream end of each branch portion 118b opens to the outer peripheral surface of the stopper portion 54 e.

As shown in fig. 2 and 4A, when the rod 54 advances to the advanced position, the tip end surface of the stopper portion 54e abuts against the inner wall surface on the tip end side of the cylinder chamber 98. Therefore, the outer peripheral surface of the stopper portion 54e faces the cylinder chamber 98 regardless of the position of the rod 54 in the advancing/retreating direction. That is, regardless of the position in the advancing/retreating direction of the rod 54, the supply path 118 is in a state of communicating with the distal end side of the piston 54a of the cylinder chamber 98 through the branch portion 118 b.

As shown in fig. 2 and 3, a piston biasing member 56 is provided between the base end surface 54ae of the piston 54a and the inner wall surface 100a on the base end side of the storage chamber 100. Therefore, as shown in fig. 2 and 4A, before the coolant is supplied to the cylinder chamber 98, the rod 54 advances to the advanced position by the spring force of the piston urging member 56. Further, as shown in fig. 4B, by supplying the coolant to the cylinder chamber 98 via the supply path 118, when the pressure of the coolant in the cylinder chamber 98 increases, the rod 54 is retracted against the spring force of the piston biasing member 56. When the rod 54 is further retracted and the base end surface 54ae of the piston 54a is brought into contact with the distal end surface 104b of the 2 nd partition 104 as shown in fig. 3 and 4C, the rod 54 reaches the retracted position.

As shown in fig. 4A, when the rod 54 is located at the advanced position, the opening 114A of the communication path 114 faces the inner peripheral surface 102a of the 1 st partition 102, thereby being in a state where the communication path 114 is not communicated with the cylinder chamber 98 and is blocked. As shown in fig. 4B, when the lever 54 retreats from the advanced position and the notch surface 50a of the cam 50 abuts against the sleeve 48, the sleeve 48 retreats. At this time, the opening 114a of the communication path 114 also faces the inner peripheral surface 102a of the 1 st partition portion 102, whereby the communication path 114 is in a state of being blocked from the cylinder chamber 98.

As shown in fig. 4C, when the rod 54 is further retracted, the opening 114a of the communication path 114 faces the cylinder chamber 98, thereby communicating the communication path 114 with the cylinder chamber 98. The position of the rod 54 at which the communication path 114 and the cylinder chamber 98 start to communicate in this way is referred to as a communication position. In the present embodiment, the communication position and the retracted position of the lever 54 are set to the same position, but the communication position may be located forward of the retracted position.

As shown in fig. 4A to 4C, a distance La from the advanced position to the retracted position of the rod 54 until the notch surface 50a of the cam 50 abuts on the sleeve 48 is smaller than a distance Lb from the advanced position to the communication position of the rod 54.

As shown in fig. 3 and 4C, when fluid is supplied to the cylinder chamber 98 through the supply passage 118 and the rod 54 is retracted to the communication position, the cylinder chamber 98 and the communication passage 114 are communicated with each other, and at this time, the coolant in the cylinder chamber 98 is supplied to the tip end side passage 112 through the communication passage 114.

As shown in fig. 3, the distal end side of the distal end side flow path 112 is fitted with the proximal end side of the 2 nd cylindrical member 122. The tip end side of the 2 nd cylindrical member 122 is slidably inserted into the base end side of the coolant flow passage 124 provided in the 1 st member 40a of the tool body 40. Accordingly, the distal end side flow passage 112 communicates with the coolant flow passage 124 through the inside of the 2 nd cylindrical member 122.

The base end side of the reamer 58 is fitted into the tip end side of the hole portion 126 of the 1 st member 40a forming the coolant flow passage 124. Accordingly, the reamer 58 is fixed to the tool body 40 so as to protrude from the tip of the 1 st member 40 a. The distal end side of the coolant flow path 124 extends between the inner peripheral surface of the hole 126 and the outer peripheral surface of the reamer 58, branches off and opens at the distal end surface of the 1 st member 40a, and opens in the vicinity of the 1 st cutting tool 42, the 2 nd cutting tool 44, and the 3 rd cutting tool 46 on the outer peripheral surface of the 1 st member 40 a. Accordingly, when the machining tool 10 is used to perform cutting, the coolant supplied from the coolant flow path 124 can be supplied to the machining point.

In the machining tool 10, the advance and retreat of the sleeve 48 can be controlled well by setting the relationship between the flow path resistance when the coolant flows out of the tool body 40 through the distal end side flow path 112, the inside of the 2 nd cylindrical member 122, and the coolant flow path 124, and the elastic biasing force of the piston biasing member 56 and the pressure of the cylinder chamber 98.

The fluid sensor 59 is provided to be able to detect at least one of the flow rate and the pressure of the coolant supplied from the coolant supply mechanism to the cylinder chamber 98. When the flow rate or pressure of the fluid detected by the fluid sensor 59 is equal to or greater than a predetermined value, it can be determined that the lever 54 has retreated to a position where the notch surface 50a of the cam 50 abuts against the sleeve 48, in other words, the sleeve 48 has retreated.

Next, the main operation of the machining tool 10 will be described. The machining tool 10 can be used by being attached to a general machine tool (not shown) having, for example, a rotary drive mechanism that rotationally drives the tool body 40, a tool body drive mechanism, and a coolant supply mechanism; the tool body driving mechanism drives the tool body 40 to advance and retreat.

First, the coolant is supplied to the supply passage 118 through the 1 st cylinder member 120 by the coolant supply mechanism, whereby the pressure of the coolant in the cylinder chamber 98 is increased. As a result, as shown in fig. 4B, the lever 54 is retracted by the distance La from the advanced position to the retracted position, and the notch surface 50a of the cam 50 abuts on the sleeve 48 to retract the sleeve 48. Therefore, the cutting edge 42a of the 1 st cutting tool 42 and the cutting edge 44a of the 2 nd cutting tool 44 directly attached to the tool body 40 advance before the cutting edge 46a of the 3 rd cutting tool 46 attached to the sleeve 48.

By further increasing the pressure of the coolant in the cylinder chamber 98, the rod 54 is retreated from the advanced position by a distance Lb larger than the distance La to reach the retreated position (communication position) as shown in fig. 3 and 4C. Accordingly, since the cylinder chamber 98 communicates with the communication path 114, the coolant supplied to the cylinder chamber 98 is supplied to the tip end side flow path 112 through the communication path 114. The coolant supplied to the tip side flow path 112 flows through the coolant flow path 124 inside the 2 nd cylindrical member 122, and flows out in the vicinity of the reamer 58, the 1 st cutting tool 42, the 2 nd cutting tool 44, and the 3 rd cutting tool 46.

In this state, while the tool body 40 is rotationally driven by the rotational driving mechanism, the tool body 40 is driven to advance and retreat by the tool body driving mechanism, and the distal end side of the tool body 40 is inserted into the opening 12a of the valve seat material 12 from one end side to the other end side in the axial direction. Accordingly, first, the reamer 58 provided at the distal end of the tool body 40 reams the valve guide hole. At this time, the coolant is supplied to the machining point or its vicinity through the inside of the tool body 40.

Next, as shown in fig. 7, cutting processing for forming the 1 st relief surface 14 and the 2 nd relief surface 18 shown in fig. 6 is performed by bringing the cutting edges 42a and 44a of the 1 st cutting tool 42 and the 2 nd cutting tool 44 into contact with the valve seat material 12. At this time, the coolant is also supplied to the machining point or its vicinity through the inside of the tool body 40. In this cutting process, the valve seat material 12 is cut by the 1 st cutting tool 42 and the 2 nd cutting tool 44 from the orthogonal end surface 28 side and the tapered surface 32 side.

After the cutting process is performed until the cut valve seat material 12 corresponds to the machining allowance S1 shown by the two-dot chain line in fig. 7, the tool body driving mechanism slightly retracts the tool body 40 toward one end side in the axial direction (arrow X1 side), thereby separating the valve seat material 12 from the 1 st cutting insert 42 and the 2 nd cutting insert 44. As a result, the 1 st cut surface 14a having the same inclination angle as the 1 st relief surface 14 and the 2 nd cut surface 18a having the same inclination angle as the 2 nd relief surface 18 are formed on the valve seat member 12.

Subsequently, the supply of the coolant to the supply passage 118 by the coolant supply mechanism is stopped, and the pressure of the coolant in the cylinder chamber 98 is lowered, whereby the rod 54 is advanced to the advanced position. Accordingly, since the arc surface 50c of the cam 50 comes into contact with the base end surface 70d of the sleeve 48, the sleeve 48 advances, and the cutting edge 46a of the 3 rd cutting tool 46 attached to the sleeve 48 advances before the cutting edge 42a of the 1 st cutting tool 42 and the cutting edge 44a of the 2 nd cutting tool 44 directly attached to the tool body 40.

In this state, while the tool body 40 is rotationally driven by the rotational driving mechanism, the tool body 40 is advanced toward the other end side (arrow X2 side) in the axial direction by the tool body driving mechanism. Accordingly, as shown in fig. 8, the cutting edge 46a of the 3 rd cutting tool 46 is brought into contact with the valve seat material 12 from which the machining allowance S1 has been removed, and cutting is performed to form the valve seat surface 16 between the 1 st cutting surface 14a and the 2 nd cutting surface 18 a. When the coolant is stopped from being supplied to the machining point through the inside of the tool body 40 and cutting is performed, the coolant may be supplied to the machining point from the outside of the tool body 40.

After the cutting process is performed as described above until the cut valve seat material 12 corresponds to the machining allowance S2 shown by the two-dot chain line in fig. 8, the tool body 40 is retracted toward the one end side in the axial direction by the tool body driving mechanism, thereby obtaining the valve seat 24 in which the 1 st retracted surface 14, the valve seat surface 16, and the 2 nd retracted surface 18 are formed in this order from the one end side in the axial direction on the inner periphery of the opening.

As described above, in the machining tool 10 according to the present embodiment, the 3 rd cutting insert 46 attached to the sleeve 48 can be advanced and retracted along the axis a. Accordingly, the 3 rd cutting insert 46 is brought into contact with the valve seat member 12 (the portion to be processed) at a different timing from the 1 st cutting insert 42 and the 2 nd cutting insert 44 directly attached to the tool body 40, and the 1 st relief surface 14, the valve seat surface 16, and the 2 nd relief surface 18 (hereinafter, these are also collectively referred to as a plurality of processing surfaces) can be processed at different timings.

Therefore, for example, the seat surface 16, which is required to be formed with higher precision than the other machined surfaces, can be machined after the other 1 st relief surface 14 and the 2 nd relief surface 18. Accordingly, the machining allowance S2 when machining the valve seat surface 16 is reduced, and the 3 rd cutting tool 46 that machines the valve seat surface 16 can be effectively prevented from being worn. As a result, the valve seat surface 16 can be machined with high precision without increasing the frequency of grinding and replacing the 3 rd cutting tool 46.

Further, since the sleeve 48 only needs to be advanced and retracted when a plurality of machining surfaces are machined at different timings, it is not necessary to perform tool replacement using a tool changer or the like, and accordingly, cutting can be efficiently performed.

Therefore, according to the machining tool 10, the cutting work can be easily performed with high accuracy and high efficiency.

In addition, in the machining tool 10, since the sleeve 48 is provided to be able to advance and retreat along the axis a, the outer dimension in the direction orthogonal to the axis a can be reduced as compared with a case where the sleeve 48 is provided to be able to advance and retreat in a direction inclined with respect to the axis a, for example. Therefore, for example, it is also easy to arrange the machining tools 10 to realize multi-axis machining or the like in order to perform cutting on the inner peripheries of the plurality of openings at a time.

The machining tool 10 according to the above-described embodiment further includes the cam biasing member 52 that elastically biases the sleeve 48 in the backward direction, the cam 50 includes the arcuate surface 50c along the outer periphery of the arc and the notched surface 50a formed by cutting out a part of the arc, and by rotating about the center of the arc as the rotation center, the arcuate surface 50c and the notched surface 50a can be selectively brought into contact with the base end surface 70d of the sleeve 48, the sleeve 48 is advanced against the elastic force of the cam biasing member 52 by bringing the arcuate surface 50c into contact with the base end surface 70d, and the sleeve 48 is moved backward by the elastic force of the cam biasing member 52 by bringing the notched surface 50a into contact with the base end surface 70 d.

In this case, as described above, the sleeve 48 can be advanced and retracted by an amount corresponding to the difference between the radius r of the arc surface 50c and the length L of the perpendicular line from the center of the arc to the notch surface 50 a. That is, compared to the case where the notch surface 50a is brought into contact with the base end surface 70d, the circular arc surface 50c along the outer periphery of the circular arc is brought into contact with the base end surface 70d of the sleeve 48, whereby the sleeve 48 can be advanced by an amount corresponding to the difference.

At this time, since the cam 50 rotates about the center of the circular arc as the rotation center, the amount of advance of the sleeve 48 can be equalized even when the base end surface 70d is brought into contact with any one portion of the circular arc surface 50 c. Therefore, the positioning accuracy of the cutting tool via the sleeve 48 can be easily maintained without adjusting the rotation amount of the cam 50 with high accuracy. Further, in a state where the arc-shaped arc surface 50c along the outer periphery of the arc is in contact with the base end surface 70d of the sleeve 48, since the cutting process is performed by the cutting tool attached to the sleeve 48, the durability of the processing tool 10 against the processing reaction force can be improved. Further, since the base end surface 70d abuts against the notch surface 50a, the state in which the sleeve 48 is retracted can be maintained well.

The machining tool 10 according to the above-described embodiment further includes the rod 54 that moves forward and backward along the axis a in the tool body 40 to rotate the cam 50, and the cylinder chamber 98; the cylinder chamber 98 is provided inside the tool body 40 and can be supplied with a fluid, the rod 54 has a piston 54a movable in the cylinder chamber 98 along an axis a, and the piston 54a is displaced by the pressure of the fluid in the cylinder chamber 98, thereby advancing and retracting the rod 54.

The rod 54 is advanced and retreated by the pressure of the coolant in the cylinder chamber 98, and thereby the 3 rd cutting tool 46 attached to the sleeve 48 can be advanced and retreated. That is, the sleeve 48 can be advanced and retracted by supplying a fluid (coolant) to the cylinder chamber 98 using a fluid supply mechanism provided in a general-purpose working machine. Therefore, the machining tool 10 is not limited to a machine tool having a drive mechanism exclusively for the sleeve 48, such as a motor or a feed screw, and is excellent in versatility because it can be attached to various machine tools having a fluid supply mechanism. In this case, the advancing and retreating direction of the sleeve 48 is not limited to the direction along the axis a, and for example, the sleeve 48 may advance and retreat in the radial direction of the tool body 40.

In the machining tool 10 according to the above-described embodiment, the rod 54 is advanced and retreated between the advanced position at the forward and retreated direction distal end and the retreated position at the forward and retreated direction proximal end, the piston 54a is elastically biased toward the distal end side of the cylinder chamber 98 by the piston biasing member 56, the cylinder chamber 98 communicates with the supply path 118 provided in the rod 54, the rod 54 is advanced to the advanced position by the elastic force of the piston biasing member 56 before the fluid (coolant) is supplied to the cylinder chamber 98, and the pressure of the fluid in the cylinder chamber 98 is increased by supplying the fluid to the cylinder chamber 98 through the supply path 118, and at this time, the rod 54 is retreated against the elastic force of the piston biasing member 56.

Accordingly, for example, when the 1 st cutting tool 42 and the 2 nd cutting tool 44 attached to the tool body 40 are brought into contact with the portion to be machined to perform cutting, the coolant is supplied to the cylinder chamber 98 through the supply passage 118, whereby the sleeve 48 is retracted, and the 3 rd cutting tool 46 attached to the sleeve 48 can be retracted from the portion to be machined.

On the other hand, when the 3 rd cutting tool 46 is brought into contact with the portion to be machined to perform cutting, the sleeve 48 can be advanced by stopping the supply of the coolant through the supply passage 118. Accordingly, the cutting process can be performed by bringing the 3 rd cutting tool 46 into contact with the workpiece instead of the 1 st cutting tool 42 and the 2 nd cutting tool 44. Therefore, a plurality of processing surfaces can be easily processed at different timings.

In the machining tool 10 according to the above-described embodiment, the rod 54 is provided with the communication path 114 and the tip end side flow path 112, the communication path 114 communicating with the cylinder chamber 98 when the rod 54 is retracted from the advanced position to the communication position and blocking the cylinder chamber 98 when the rod 54 is located on the tip end side of the communication position, the tip end side flow path 112 communicating with the communication path 114 and extending from the communication path 114 to the tip end side, the fluid being supplied to the cylinder chamber 98 through the supply path 118, the rod 54 being retracted to the communication position, and thereby the coolant being supplied to the tip end side flow path 112 when the cylinder chamber 98 is communicated with the communication path 114.

Accordingly, when the rod 54 is retracted to the communication position by supplying the coolant to the cylinder chamber 98 through the supply passage 118, the coolant can be supplied to the tip end side passage 112 through the communication passage 114. That is, when the sleeve 48 is retracted, the coolant can be supplied to a machining point or the like outside the tool body 40 through the coolant flow passage 124.

In the rod 54 of the machining tool 10 according to the above-described embodiment, the communication path 114 is provided on the distal end side of the piston 54a, the bulging portion 54b bulging from the outer peripheral surface of the rod 54 is provided on the distal end side of the communication path 114, the cam 50 is provided with the concave portion 50b into which the bulging portion 54b is insertable, and the rod 54 is advanced to the advanced position while the bulging portion 54b is brought into contact with the inner surface of the concave portion 50b, whereby the cam 50 is rotated so that the circular arc surface 50c is brought into contact with the proximal end surface 70d of the sleeve 48, and the rod 54 is retracted to the retracted position while the bulging portion 54b is brought into contact with the inner surface of the concave portion 50b, whereby the cam 50 is rotated so that the notch surface 50a is brought into contact with the proximal end surface 70d of the sleeve 48.

In this case, as described above, in the case where the base end surface 70d of the sleeve 48 is brought into contact with any one portion of the arcuate surface 50c, the advance amounts of the sleeve 48 can be made equal, and therefore, the positioning accuracy of the 3 rd cutting tool 46 via the sleeve 48 can be easily maintained with a simple configuration without adjusting the advance and retreat amounts of the rod 54 with high accuracy.

In the machining tool 10 according to the above-described embodiment, the distance La from the forward position of the rod 54 to the backward position where the notch surface 50a of the cam 50 abuts against the base end surface 70d of the sleeve 48 is smaller than the distance Lb from the forward position of the rod 54 to the backward position to the communicating position. If clogging of slag or the like generated by cutting occurs on the upstream side of the coolant in the cylinder chamber 98, the flow rate (supply amount) of the coolant supplied to the cylinder chamber 98 may decrease.

Therefore, for example, as shown in fig. 4A, when the rod 54 is located at the forward position, if the supply amount of the coolant is reduced, the pressure of the cylinder chamber 98 is less likely to be increased, and the sleeve 48 may be less likely to be retracted. Even in this case, the cylinder chamber 98 does not communicate with the communication path 114 until the rod 54 is retracted until the notch surface 50a of the cam 50 comes into contact with the base end surface 70d of the sleeve 48 (until the sleeve 48 is retracted). Accordingly, the coolant of the cylinder chamber 98 can be prevented from flowing out through the communication path 114, and accordingly the pressure of the cylinder chamber 98 can be easily raised. As a result, the sleeve 48 can be easily retracted.

Further, the distance La by which the rod 54 is retreated from the advanced position until the notch surface 50a abuts against the base end surface 70d of the sleeve 48 is set short relative to the distance Lb by which the rod 54 is retreated from the advanced position to the retreated position, whereby the sleeve 48 can be easily retreated.

Further, for example, as shown in fig. 4C, when the rod 54 is located at the retreating position, if the supply amount of the coolant is reduced, the pressure of the cylinder chamber 98 is likely to be reduced, and there is a fear that it is difficult to maintain the sleeve 48 in a state where the sleeve 48 is retreated. In this case, as shown in fig. 4B, before the rod 54 advances to a position where the arc surface 50c of the cam 50 abuts against the base end surface 70d of the sleeve 48 (a position where the sleeve 48 advances), the communication between the cylinder chamber 98 and the communication path 114 is also blocked. Accordingly, the coolant of the cylinder chamber 98 can be prevented from flowing out through the communication path 114, and accordingly, the pressure of the cylinder chamber 98 can be made less likely to drop. As a result, the state in which the sleeve 48 is retracted can be maintained well.

In the machining tool 10 according to the above-described embodiment, the fluid is a coolant supplied to the machining point of the workpiece. The working machine to which the machining tool 10 for performing cutting machining is attached is a general working machine having a coolant supply mechanism for supplying coolant to a machining point. Therefore, the sleeve 48 is made to advance and retreat by the supply and discharge of the coolant, whereby the kinds of attachable working equipment can be increased, and the versatility of the machining tool 10 can be further improved. Further, the fluid supplied to the cylinder chamber 98 is not limited to the coolant. A fluid other than a coolant such as air may be supplied to cylinder chamber 98.

The machining tool 10 according to the above-described embodiment further includes the fluid sensor 59, and the fluid sensor 59 detects at least one of the flow rate and the pressure of the fluid supplied to the cylinder chamber 98. In this case, when the flow rate or pressure of the fluid detected by the fluid sensor 59 is equal to or greater than a predetermined value, it can be determined that the lever 54 has retreated to a position where the notch surface 50a of the cam 50 abuts against the sleeve 48, in other words, the sleeve 48 has retreated. Therefore, by monitoring the detection result of the fluid sensor 59, the relative position of the 3 rd cutting tool 46 with respect to the tool body 40 (the 1 st cutting tool 42 and the 2 nd cutting tool 44) can be more reliably adjusted, and cutting can be performed with high accuracy.

In the machining tool 10 according to the above-described embodiment, the sleeve 48 is disposed in the tool body 40 so as to be slidable inside the groove 72 formed along the axis a, and the groove 72 has the 1 st inner wall surface 72a and the 2 nd inner wall surface 72b, and the 1 st inner wall surface 72a is in contact with the end surface 78 on the rear side in the rotation direction of the sleeve 48 that rotates together with the tool body 40; the 2 nd inner wall surface 72b abuts on an end surface 80 on the axial line a side of the sleeve 48, and a plate spring 82 (pressing member) is provided in the tool body 40, and the plate spring 82 presses the sleeve 48 in a direction inclined with respect to the 1 st inner wall surface 72a and the 2 nd inner wall surface 72b from the front in the rotation direction of the sleeve 48.

When cutting is performed using the 3 rd cutting tool 46 attached to the sleeve 48, the sleeve 48 receives cutting resistance from the front toward the rear in the rotational direction. Therefore, by bringing the socket 48 into contact with the 1 st inner wall surface 72a and the 2 nd inner wall surface 72b, the cutting work can be performed in a state where the socket 48 is stably fixed to the tool body 40, and the machining accuracy can be improved. Further, by the plate spring 82 pressing the sleeve 48 in the above-described direction, the sleeve 48 can be advanced and retreated along the axis a while overcoming the elastic force of the plate spring 82, and the sleeve 48 that receives the centrifugal force at the time of cutting can be effectively prevented from being separated from the tool body 40. Instead of the plate spring 82, various kinds of pressing members that can press the sleeve 48 as described above may be used.

In the machining tool 10 according to the above-described embodiment, the plurality of machining surfaces are the valve seat surface 16 of the cylinder head 22 and the 1 st relief surface 14 and the 2 nd relief surface 18 provided on each end side in the axial direction of the valve seat surface 16, and the plurality of cutting tools include the 1 st cutting tool 42 forming the 1 st relief surface 14, the 2 nd cutting tool 44 forming the 2 nd relief surface 18, and the 3 rd cutting tool 46 forming the valve seat surface 16, the 1 st cutting tool 42 and the 2 nd cutting tool 44 are directly attached to the tip end portion of the tool body 40, and the 3 rd cutting tool 46 is attached to the tip end portion of the sleeve 48.

As described above, since the valve seat surface 16 is a contact surface with which the valve contacts, the roundness, the surface roughness, and the like need to be adjusted with higher accuracy than the 1 st receding surface 14 and the 2 nd receding surface 18. By machining the 1 st relief surface 14 and the 2 nd relief surface 18 with the 1 st cutting tool 42 and the 2 nd cutting tool 44 and then machining the valve seat surface 16 with the 3 rd cutting tool 46, the machining allowance S2 (see fig. 8) at the time of machining the valve seat surface 16 can be reduced. Accordingly, since the 3 rd cutting insert 46 can be effectively prevented from being worn, the valve seat surface 16 can be accurately machined without increasing the frequency of grinding and replacing the 3 rd cutting insert 46.

Further, the 1 st cutting tool 42 and the 2 nd cutting tool 44 that machine the 1 st relief surface 14 and the 2 nd relief surface 18 that are larger than the valve seat surface 16 by the machining allowance S1 (see fig. 7) for the cutting are directly attached to the tool body 40. Accordingly, since the 1 st cutting insert 42 and the 2 nd cutting insert 44 can be more firmly attached to the tool body 40 than by the sleeve 48, it is possible to suppress the occurrence of vibration or the like due to machining, thereby achieving an improvement in machining accuracy and an improvement in durability. Further, since the machining allowance S2 can be reduced in the valve seat surface 16 as described above, sufficient machining accuracy can be obtained even if the 3 rd cutting tool 46 for machining the valve seat surface 16 is provided in the sleeve 48.

In addition, in the machining tool 10, the 1 st cutting insert 42 and the 2 nd cutting insert 44 are directly attached to the tool body 40, and thus only the sleeve 48 for advancing and retracting the 3 rd cutting insert 46 may be provided. Therefore, the number of the sleeves 48 attached to the tool body 40 can be reduced as much as possible, and the outer dimension in the direction orthogonal to the axis a can be effectively reduced.

In the machining tool 10 according to the above-described embodiment, the reamer 58 for machining the valve guide hole is fixed to the distal end of the tool body 40. In this case, the reamer 58 can be rotated and advanced and retracted by rotating and advancing and retracting the tool body 40 by the rotation driving mechanism and the tool body driving mechanism. That is, since machining can be performed using the reamer 58 without using a driving mechanism dedicated to reaming, limitation of working equipment to which the machining tool 10 can be attached can be avoided, and versatility of the machining tool 10 can be further improved.

The present invention is not particularly limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention.

For example, in the machining tool 10, the 3 rd cutting insert 46 may be directly attached to the distal end portion of the tool body 40. In this case, the machining tool 10 may have two sleeves 48, and the 1 st cutting tool 42 may be attached to one sleeve 48, and the 2 nd cutting tool 44 may be attached to the other sleeve 48. Alternatively, the 1 st cutting insert 42 and the 2 nd cutting insert 44 may be attached to one sleeve 48.

In this case, the 1 st and 2 nd relief surfaces 14 and 18 can be machined by the 1 st and 2 nd cutting tools 42 and 44, and then the 3 rd cutting tool 46 can machine the valve seat surface 16. Therefore, the machining allowance S2 when machining the valve seat surface 16 can be reduced, and the valve seat surface 16 can be machined with high accuracy without increasing the frequency of grinding and replacing the 3 rd cutting tool 46. In this case, since the 3 rd cutting tool 46 firmly attached to the tool body 40 can be used to machine the valve seat surface 16, the machining accuracy of the valve seat surface 16 can be further effectively improved.

The plurality of cutting tools included in the machining tool 10 is not limited to 3 cutting tools, i.e., the 1 st cutting tool 42, the 2 nd cutting tool 44, and the 3 rd cutting tool 46. The number of cutting tools may be set according to the number of machining surfaces formed on the inner periphery of the opening, and may be 2 or 4 or more.

Description of the reference numerals

10: a machining tool; 12: a valve seat material; 12 a: an opening; 14: a 1 st retreat surface; 16: a valve seat surface; 18: a 2 nd evacuation surface; 22: a cylinder head; 40: a tool body; 42: 1 st cutting tool; 44: a 2 nd cutting tool; 46: a 3 rd cutting tool; 48: a sleeve; 50: a cam; 50 a: a notch surface; 50 b: a recess; 50 c: a circular arc surface; 52: a cam urging member; 54: a rod; 54 a: a piston; 54 b: a bulging portion; 56: a piston force application member; 58: a reamer; 59: a fluid sensor; 70 d: a basal end face; 72: a groove; 72 a: 1 st inner wall surface; 72 b: the 2 nd inner wall surface; 74 a: a pressed surface; 78. 80: an end face; 82: a plate spring; 98: a cylinder chamber; 112: a tip-side flow path; 114: a communication path; 118: a supply path.