Working machinery

Abstract

The present invention provides a machine tool equipped with a configuration for fixing the rotational movement of a turning tool mounted on the spindle, and which can be used for heavy turning with a large turning load. [Solution] A machine tool having a spindle 10 on which a turning tool 20 is mounted, the tool having a turning tool 23 and a holder 21, the holder having an anti-rotation locking piece 22 on its outer circumference, the spindle head having an anti-rotation bracket 40 that fixes the rotational movement of the tool, the anti-rotation bracket having a pin support base 42 and a movable pin 43 that is slidably supported in a support hole provided in the pin support base, the tool being connected to the tool by inserting the tip of the movable pin into a through hole 22a of the anti-rotation locking piece provided in the holder of the tool mounted on the spindle, a fluid supply pipe P that supplies fluid at a predetermined pressure is connected to the pin support base and the movable pin is biased downward by the fluid supplied from the fluid supply pipe.

Description

Technical Field

[0005] , , , ,

[0004] , , ,

[0001] The present invention relates to a machine tool, for example, a machine tool provided with a mechanism for fixing the movement of a tool mounted on a spindle in the turning direction and capable of performing turning machining.

Background Art

[0002] Conventionally, a turning tool (a turning tool having a turning tool (square bit, round bit) and a holder for holding the turning tool) is mounted on the spindle of a machine tool, the spindle motor is locked, and a mechanism for fixing the rotational movement of the holder in the turning direction (for the sake of convenience of explanation, referred to as a "locking mechanism") is provided, whereby the surface of a workpiece is machined by turning on the machine tool. Such a configuration of the machine tool is disclosed in, for example, Patent Document 1.

[0003] The locking mechanism of the machine tool described in Patent Document 1 has a plate-like locking flange attached to the lower surface of the holder (tool holder) and an engaging protrusion provided so as to protrude downward on the lower surface of the spindle head that supports the spindle. A pin protrudes from the lower end of the engaging protrusion. Further, an engaging hole is provided in the locking flange. Then, by inserting the tip of the pin of the engaging protrusion into the engaging hole of the locking flange and engaging them, the movement of the holder in the turning direction is fixed. Thereby, rotation around the central axis of the tool and movement of the tool due to a force applied in the radial direction are prevented, enabling turning machining to be performed.

[0004] The engaging protrusion is integrally formed by a base and a pin or the like, and the pin protrudes from the support base. Specifically, the base includes a pair of support bases and a connecting portion 50b that connects the pair of support bases. The support bases are columnar, and the upper end surfaces are in contact with the lower end surface of the spindle head. The connecting portion is plate-like and connects the side surfaces of the pair of support bases.

[0005] The pin is formed in the shape of a hollow round bar and is supported within a support hole provided in the support base, allowing it to slide freely in the axial direction. A stopper bolt is inserted from above into the hollow portion of the pin. The threaded portion at the lower end of the stopper bolt is connected to the lower part of the pin, and the head of the stopper bolt abuts against the upper surface of a stepped portion provided on the inner circumference of the middle part of the support hole. The lower surface of the stepped portion faces the upper end of the pin, and a compression spring is interposed between them. With the above configuration, the pin is biased downward by the compression spring, but is stopped at a position where the head of the stopper bolt abuts against the stepped portion, and is supported in a state where it protrudes an appropriate length below the support base. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Patent No. 5853814 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The anti-rotation mechanism for a machine tool described in Patent Document 1 above utilizes spring force to increase the coupling force between the engagement hole of a plate-shaped anti-rotation flange provided on the holder and the pin of the engagement projection provided on the spindle head. However, the anti-rotation mechanism for machine tools described in Patent Document 1 uses spring force to increase the coupling force between the engagement hole of the anti-rotation flange provided on the holder and the pin of the engagement projection provided on the spindle head. However, when used for heavy turning with a large turning load, such as when turning iron-based materials, there is a problem that the coupling may become loose. In other words, the anti-rotation mechanism for machine tools described in Patent Document 1 has the problem that it may not be usable for heavy turning.

[0008] The present invention has been made in view of the above problems, and its purpose is to provide a machine tool equipped with a configuration for fixing the rotational movement of a turning tool mounted on a spindle, which can be used for heavy turning with a large turning load. [Means for solving the problem]

[0009] The present invention, made to solve the above problems, is a machine tool having a spindle head on which a spindle to which a turning tool is mounted is provided, wherein the turning tool consists of a turning tool and a holder that holds the turning tool and is mounted on the spindle, a substantially columnar anti-rotation locking piece projecting radially outward is formed on the outer circumference of the holder, and a through hole is provided in the anti-rotation locking piece, the spindle head is provided with an anti-rotation bracket that fixes the rotational movement of the turning tool, the anti-rotation bracket has a pin support base fixed to the lower end of the spindle head and a movable pin disposed inside a pin support hole provided at the end of the pin support base and slidably supported in the pin support hole, the pin support base has the pin support hole extending vertically formed on one end and an opening formed on the side of the other end, A flow channel is formed in this opening that extends toward and communicates with the pin support hole, a fluid supply pipe that supplies fluid at a predetermined pressure is connected to the opening, the movable pin is a substantially hollow cylindrical shape with a hole formed therein that extends axially from its upper end to its lower end, its tip protrudes downward by a predetermined length from the lower end of the pin support base, the anti-rotation bracket is coupled to the turning tool by inserting the tip of the movable pin into a through hole in the anti-rotation locking piece provided in the holder of the turning tool mounted on the spindle, thereby fixing the rotational movement of the turning tool, the fluid supplied from the fluid supply pipe flows through the opening and the flow channel hole into the hole of the movable pin installed in the pin support hole, and the movable pin is biased downward by the fluid.

[0010] Thus, in this invention, the fluid supplied from the fluid supply pipe flows through the opening and flow path hole of the anti-rotation bracket into the hole of the movable pin installed in the pin support hole of the anti-rotation bracket, and the movable pin is biased downward by the fluid. Therefore, for example, even if the movable pin inserted into the through-hole of the anti-rotation locking piece is subjected to an upward load due to the turning process, the fluid pressure (by the principle of a piston) biases the movable pin downward, preventing it from moving upward and causing looseness between it and the anti-rotation locking piece, or from coming out of the through-hole.

[0011] Furthermore, the force that biases the movable pin using only spring force, as in the invention described in Patent Document 1 above (referred to as "pressure thrust" for convenience of explanation), is approximately "50N". On the other hand, suppose the fluid supplied from the fluid supply pipe is the same as the center-through coolant supplied to the machine tool. In this case, since the pressure of the center-through coolant is generally "1.5 MPa", if we calculate the pressing thrust force against the movable pin assuming the pressure of the supplied fluid is "1.5 MPa", it will be "approximately 259 N" (the calculation method is shown in the description of the best mode for carrying out the invention). In other words, the present invention has a configuration that can significantly improve the pressing thrust force of the movable pin, and the coupling rigidity between the turning tool and the movable pin of the anti-rotation bracket is increased. Therefore, even when the machine tool of the present invention is used in turning operations with a large turning load, looseness in the joint between the turning tool and the anti-rotation bracket is suppressed.

[0012] Furthermore, the through hole of the anti-rotation locking piece is tapered, and the movable pin is the pin support base pin It is desirable that the movable pin is able to move vertically by a spring provided in the support hole, and that a tapered portion is formed on its tip, so that when the tapered portion at the tip of the movable pin is inserted into the through hole of the anti-rotation locking piece, the tapered portion and the inner circumferential surface of the tapered shape of the through hole come into contact.

[0013] Thus, in this invention, when the tapered portion at the tip of the movable pin is inserted into the through-hole of the anti-rotation locking piece, the tapered portion and the inner circumferential surface of the tapered shape of the through-hole come into contact. This configuration improves the rigidity against radial load at the joint between the turning tool and the movable pin of the anti-rotation bracket. Also, the movable pin is attached to the pin support base. pin Because it can move vertically thanks to a spring installed in the support hole, it can absorb dimensional errors caused by part manufacturing.

[0014] Furthermore, the turning tool has a body portion, a flange portion formed on the upper surface of the body portion, and a cutting edge portion mounted below the body portion. The body portion is formed in a substantially cylindrical shape, and has a cutting edge mounting portion with a substantially 3 / 4 circular cross-section at its lower end, and the cutting edge portion is mounted on the cutting edge mounting portion. The flange portion has a plurality of first bolt holes formed at equal intervals in the circumferential direction around its center. The holder constituting the turning tool is formed in a substantially cylindrical shape, and has second bolt holes on its lower end surface corresponding to the first bolt holes of the flange portion. The turning tool is preferably coupled to the holder by bringing the upper surface of the flange portion into contact with the lower end surface of the holder, inserting bolts into the first and second bolt holes, and fastening the bolts. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a machine tool equipped with a configuration for fixing the rotational movement of a turning tool mounted on a spindle, which can be used for heavy turning with a large turning load. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram showing a side view of a machine tool according to an embodiment of the present invention. [Figure 2]It is a schematic diagram showing an enlarged view of part A shown in FIG. 1, and shows a spindle, a tool mounted on the spindle, and a detent bracket for preventing rotation in the turning direction of the tool. [Figure 3] It is a schematic diagram showing the component parts of the main part of the detent bracket of the machine tool according to the embodiment of the present invention. [Figure 4] It is a schematic diagram for explaining the configuration of the detent bracket of the machine tool according to the embodiment of the present invention. (a) is a schematic diagram showing the configuration of the detent bracket in a cross-sectional view, and (b) is a schematic diagram showing the flow of fluid for biasing the movable pin of the detent bracket downward. [Figure 5] It is a schematic diagram for explaining the configuration of the turning tool held by the holder mounted on the spindle of the machine tool according to the embodiment of the present invention, and shows a schematic diagram of the turning tool viewed obliquely from above. [Figure 6] It is a schematic diagram for explaining the configuration of the turning tool held by the holder mounted on the spindle of the machine tool according to the embodiment of the present invention, and shows a schematic diagram of the turning tool viewed from the side. [Figure 7] It is a schematic diagram for explaining the configuration for coupling the holder mounted on the spindle of the machine tool according to the embodiment of the present invention and the turning tool held by the holder.

Best Mode for Carrying Out the Invention

[0017] Hereinafter, the machine tool according to the embodiment of the present invention will be described based on the drawings.

[0018] 《Schematic Configuration of Machine Tool》 First, the schematic configuration of the machine tool according to the embodiment of the present invention will be described with reference to FIGS. 1 and Here, FIG. 1 is a schematic diagram showing the side of the machine tool of the present embodiment. FIG. 2 is a schematic diagram showing an enlarged view of part A shown in FIG. 1, and shows a spindle, a tool mounted on the spindle, and a detent bracket for preventing rotation in the turning direction of the tool.

[0019] The machine tool W of this embodiment includes a spindle head 6 on which a spindle 10 can be selectively mounted with cutting tools and turning tools 20, a spindle motor for rotating the spindle 10, a Z-axis motor for moving the spindle in the axial direction (Z direction) of the spindle, a magazine 7 for mounting and removing tools from the spindle 10, a control unit (not shown) for controlling the operation of the machine tool W, and a display unit (illustrated). Furthermore, the machine tool W is equipped with a rotation-preventing bracket 40 (see Figure 2) to fix the rotational movement of the turning tool 20 in the pivoting direction when the turning tool 20 is mounted on the spindle 10, thereby enabling turning of the workpiece.

[0020] Specifically, as shown in Figure 1, the machine tool W includes a bed 1, a Y-axis drive unit 2 located above the bed 1, a table 3 supported on the upper surface of the Y-axis drive unit 2, a column 4 extending upward from the upper surface of the bed 1, an arm 5 extending parallel to the upper surface of the bed 1 from the upper end of the column 4, a spindle head 6 located on the arm 5, a magazine (rotating magazine) 7 supported on the arm 5, a control unit (not shown) for controlling the operation of the machine tool W, a display unit (not shown) consisting of a display device such as a liquid crystal display, and an operation panel (operation unit (not shown)) consisting of various operation buttons, ON / OFF switches, etc.

[0021] Furthermore, the spindle head 6 is provided with a spindle bearing that rotatably supports the spindle 10, and the spindle 10 is designed so that tools (cutting tools, turning tools 20) can be detachably attached to its end.

[0022] Furthermore, cutting tools not shown in the diagram consist of a cutting tool such as a drill and a standard type holder (cutting holder) for holding the cutting tool. Furthermore, the turning tool 20 comprises a turning tool (turning insert) 23 and a holder (turning holder) 21 that holds the turning tool 23. The turning holder 21 has a different structure from a standard type holder that holds a cutting tool, and is connected to an anti-rotation bracket 40, which will be described below, and is configured to prevent the turning tool 20 from rotating in the rotational direction (the rotational direction of the spindle 10).

[0023] Specifically, as shown in Figure 2, the holder 21 constituting the turning tool 20 has a roughly columnar anti-rotation locking piece 22 formed on its outer circumference, which protrudes radially outward. A through hole 22a is provided in this anti-rotation locking piece 22, and a movable pin 43 provided on the anti-rotation bracket 40 shown below is inserted into this through hole 22a. This through-hole 22a has a tapered shape in which the diameter gradually decreases in the direction from the upper surface to the lower surface (Z1 direction).

[0024] The anti-rotation bracket 40 is fixed to the lower end of the spindle head 6. Specifically, the anti-rotation bracket 40 includes a columnar vertical piece 41 extending downward from the lower end of the spindle head 6, a substantially L-shaped columnar pin support base 42 extending from the lower end of the vertical piece 41 (the pin support base 42 is fixed to the lower end of the spindle head 6 via the vertical piece 41), and a movable pin 43 that is slidably supported inside a pin support hole 42b provided at the end of the pin support base 42. As described below, the movable pin 43 is supported by the pin support base 42 in a state that allows it to move vertically by a spring S provided in the pin support hole 42b of the pin support base 42, and its tip protrudes downward by a predetermined length from the lower end of the pin support base 42.

[0025] Anti-rotation bracket 40 Next, the configuration of the anti-rotation bracket 40 will be explained with reference to Figures 3 and 4. Here, Figure 3 is a schematic diagram showing the main components of the anti-rotation bracket of the machine tool according to this embodiment. Figure 4 is a schematic diagram illustrating the configuration of the anti-rotation bracket of the machine tool according to this embodiment, where (a) is a schematic diagram showing the configuration of the anti-rotation bracket in cross-section, and (b) is a schematic diagram showing the fluid flow that biases the movable pin of the anti-rotation bracket downward. Note that in Figure 4(b), the spring S is omitted (the spring S is not shown) in order to make the fluid flow easier to understand.

[0026] Specifically, as shown in Figure 3, the roughly L-shaped columnar pin support base 42 has a pin support hole 42b formed at one end that penetrates vertically (in the Z direction in the figure). The pin support hole 42b has a small diameter portion 42b1 at one end (upper end) and a large diameter portion 42b3 that expands from the lower end of the small diameter portion 42b1 (having a larger diameter than the small diameter portion 42b1), with a stepped portion 42b2 at the boundary between the small diameter portion 42b1 and the large diameter portion 42b3. The movable pin 43 is housed in the large diameter portion 42b3 of this pin support hole 42b. Furthermore, the pin support base 42 has an opening 42a1 formed on the side surface of the other end, and a flow channel hole 42a2 is formed that extends horizontally (in the X direction in the figure) from this opening 42a1 toward the pin support hole 42b on the one end side and communicates with the pin support hole 42b.

[0027] The movable pin 43 is a substantially hollow cylindrical shape with a hole 43a formed therein that extends axially from one end (upper end) to the other end (lower end). The hole 43a has a large diameter portion 43a1 that extends axially downward from one end (upper end) and a small diameter portion 43a3 that narrows in diameter from the lower end of the large diameter portion 43a and extends axially downward, with a stepped portion 43a2 at the boundary between the small diameter portion 43a3 and the large diameter portion 43a1. The small diameter portion 43a3 has a screw groove formed therein that engages with the screw portion formed on the lower end side of the shaft portion 44b of the stopper bolt 44.

[0028] Furthermore, the movable pin 43 has a tapered portion 43c formed on its tip side. Specifically, the movable pin 43 has a cylindrical portion 43b and a tapered portion 43c extending downward from the lower end of the cylindrical portion 43b, and the tapered portion 43c is inserted into the through hole 22a of the anti-rotation locking piece 22. Furthermore, the diameter of the cylindrical portion 43b of the movable pin 43 is slightly smaller than the diameter of the pin support hole 42b of the pin support base 42. When inserted into the pin support hole 42b, the outer surface of the movable pin 43 comes into contact with the inner surface of the pin support hole 42b, and the movable pin can move in the axial direction (Z direction). As mentioned above, the through hole 22a of the anti-rotation locking piece 22 also has a tapered shape. Therefore, when the tapered portion 43c at the tip of the movable pin 43 is inserted into the through hole 22a of the anti-rotation locking piece 22, the tapered portion 43c and the inner circumferential surface of the tapered shape of the through hole 22a make solid contact, improving the rigidity against radial load at the joint between the turning tool 20 and the movable pin 43 of the anti-rotation bracket 40.

[0029] The stopper bolt 44 has a head 44a and a shaft 44b, with the lower end of the shaft 44b being a threaded portion that screws into the thread groove formed in the smaller diameter portion 43a3 at the lower end of the hole 43a of the movable pin 43. The head 44a of the stopper bolt 44 has a diameter larger than the smaller diameter portion 42b1 of the pin support hole 42b of the pin support base 42. The shaft 44b of the stopper bolt 44 has a diameter smaller than the smaller diameter portion 42b1 of the pin support hole 42b of the pin support base 42. Furthermore, the spring S is, for example, a coil spring, whose diameter is smaller than the diameter of the large-diameter portion 43a1 of the hole 43a of the movable pin 43, and larger than the diameter of the small-diameter portion 43b3.

[0030] Then, as shown in Figure 3, the spring S is inserted into the hole 43a of the movable pin 43, and the spring S is placed on the stepped portion 43a2 of the hole 43a. The movable pin 43 is then inserted from below the pin support base 42 into the large diameter portion 43b3 of the pin support hole 42b of the pin support base 42. As a result, the spring S is sandwiched between the stepped portion 42b2 of the pin support hole 42b of the pin support base 42 and the stepped portion 43a2 of the hole 43a of the movable pin 43. Furthermore, the shaft portion 42b of the stopper bolt 44 is inserted through the pin support hole 42b of the pin support base 42 from above, and the shaft portion 44b of the stopper bolt 44 is inserted inside the hole 43a of the movable pin 43 and the spring S located in the hole 43a. In addition, the stopper bolt 44 and the movable pin 43 are connected by screwing the threaded portion formed on the lower end of the stopper bolt 44 into the threaded groove of the small diameter portion 43a3 of the hole 43a of the movable pin 43.

[0031] Furthermore, a fluid supply pipe P is connected to the opening 42a1 to supply a fluid (gas or liquid (such as coolant)) at a predetermined pressure, and the fluid supplied from the fluid supply pipe P flows through the opening 42a1 and the flow path hole 42a2 into the hole 43a1 of the movable pin 43 installed inside the pin support hole 42b. The fluid supply pipe P is connected to a coolant system (not shown) that has a pump to supply coolant to the machine tool W at a predetermined pressure. Alternatively, the fluid supply pipe P is connected to an air pump (not shown) that supplies air at a predetermined pressure.

[0032] Furthermore, an O-ring 101 is fitted to the upper outer circumference of the shaft portion 44b of the stopper bolt 44. Also, an O-ring 102 is fitted to the lower outer circumference of the cylindrical portion 43b of the movable pin 42. These O-rings 101 and 102 prevent the ingress of cutting fluid.

[0033] As shown in Figure 4(a), the anti-rotation bracket 40 configured as described above is connected to the turning tool 20 by inserting the tip of the movable pin 43 of the anti-rotation bracket 40 into the through hole 22a of the anti-rotation locking piece 22 provided on the outer circumference of the holder 21 of the turning tool 20 mounted on the spindle 10, thereby fixing the rotational movement of the turning tool 20 in the pivoting direction.

[0034] Furthermore, as shown in Figure 4(a), in the anti-rotation bracket 40, the spring S is sandwiched between the stepped portion 42b2 of the pin support hole 42b of the pin support base 42 and the stepped portion 43a2 of the hole 43a of the movable pin 43, and the spring S allows the movable pin 43 to move in the vertical direction (Z direction). This configuration absorbs dimensional errors caused by the manufacturing of the parts. Furthermore, as shown in Figure 4(b), the anti-rotation bracket 40 is configured such that the fluid supplied from the fluid supply pipe P flows through the opening 42a1 and the flow path hole 42a2 into the hole 43a1 of the movable pin 43 installed in the pin support hole 42b. Therefore, even if the movable pin 43, which is inserted into the through hole 22a of the anti-rotation locking piece 22, is subjected to an upward load (Z2 direction) due to the turning operation, the fluid pressure (by the piston principle) biases the movable pin 43 downward (Z1 direction), preventing the movable pin 43 from moving upward (Z2 direction) and causing looseness between it and the locking piece 22, or from coming out of the through hole 22a.

[0035] Let's assume that the fluid supplied from the fluid supply pipe P is the same as the center-through coolant supplied to the machine tool W. In this case, since the pressure of the center-through coolant is generally "1.5 MPa", if we calculate the thrust force pressing the movable pin using the pressure of the supplied fluid as "1.5 MPa", the thrust force will be "approximately 259 N", as shown in (Equation 1) below.

number

[0036] Thus, in this embodiment, the movable pin 43 of the anti-rotation bracket 40, which is inserted into the through hole 22a of the anti-rotation locking piece 22 provided on the outer circumference of the holder 21 of the turning tool 20, is configured to be biased downward by fluid pressure (by the principle of a piston), and the pushing thrust of the movable pin 43 can be greatly improved (in this embodiment, the bonding rigidity between the turning tool 20 and the movable pin 43 of the anti-rotation bracket 40 is increased). Therefore, even when the machine tool W of this embodiment is used for turning operations with a large turning load, looseness in the joint between the turning tool 20 and the anti-rotation bracket 40 is suppressed. In other words, the machine tool W of this embodiment can be used for heavy turning operations such as turning iron-based materials, where the turning load is large.

[0037] 《Connection structure between turning tool 23 and holder 21》 Next, the coupling structure of the turning tool 23 and holder 21 that constitute the turning tool 20 of this embodiment will be described with reference to Figures 5 to 7.

[0038] Here, Figure 5 is a schematic diagram illustrating the configuration of a turning tool held in a holder mounted on the spindle of the machine tool of this embodiment, showing a schematic view of the turning tool from diagonally above. Figure 6 is a schematic diagram illustrating the configuration of a turning tool held in a holder mounted on the spindle of the machine tool of this embodiment, showing a schematic view of the turning tool from the side. Figure 7 is a schematic diagram illustrating the configuration connecting the holder mounted on the spindle of the machine tool of this embodiment and the turning tool held in the holder.

[0039] As shown in Figures 5 and 6, the turning tool 23 constituting the turning tool 20 has a body portion (shank) 230, a disc-shaped flange portion 232 formed on the upper surface of the body portion 230, and a cutting edge portion 231 mounted below the body portion 230. The body portion 230 is formed in a roughly cylindrical shape, and at its lower end is a blade mounting portion with a roughly 3 / 4 circular cross-section, to which the blade portion 231 is attached. Furthermore, the flange portion 232 has a substantially circular protrusion 233 formed in its center, and four first bolt holes 232a are formed around the protrusion 233 at equal intervals in the circumferential direction.

[0040] Furthermore, as shown in Figure 7, the holder 21 constituting the turning tool 20 is formed in a substantially cylindrical shape, and the turning tool 23 is fixed to its lower end surface by multiple (four) bolts B. Specifically, the holder 21 has a circular recess (not shown) formed in the center of its lower end surface that engages with the protrusion 233 of the flange portion 232 of the turning tool 23, and second bolt holes (not shown) corresponding to the four first bolt holes 232a of the flange portion 232 are provided around the recess.

[0041] Then, the upper surface of the flange portion 232 is brought into contact with the lower end surface of the holder 21, and the convex portion 233 on the upper surface of the flange portion 232 of the turning tool 23 is engaged with the recess in the lower end surface of the holder 21, and the bolt B is inserted into the first bolt hole 232a and the second bolt hole and fastened, thereby connecting the turning tool 23 to the holder 21.

[0042] This configuration was adopted for the following reasons. Conventional turning tools used in machine tools, known as square cutting tools, have a cutting edge at the lower end of a roughly rectangular prism-shaped body (shank). A common method for attaching a square cutting tool to a holder involves leaving one of the four sides of the body open and securing the tool to the holder with a bolt that passes through the holder's side. This method suffers from low rigidity in the radial and thrust directions. Furthermore, while the round cutting tool (cutting tool) is fixed to the holder by a bolt that passes through the side of the holder, this also presents a problem: the length of the spigot joint, which is the connection point with the holder, weakens the torsional rigidity of the round cutting tool (cutting tool).

[0043] Therefore, in this embodiment, a disc-shaped flange portion 232 is provided on the upper surface of the body portion (shank) 230 of the turning tool 23, and the upper surface of the flange portion 232 is brought into contact with the lower end surface of the holder 21. The turning tool 23 is then connected to the holder 21 by a flange connection, which involves fastening four bolts B that pass through the flange portion 232. This configuration allows for increased rigidity in the radial and thrust directions compared to conventional methods of connecting a square cutting tool and a holder. Furthermore, compared to conventional methods of connecting a round cutting tool and a holder, the connection between the turning tool and the holder can be shortened, thereby increasing the torsional rigidity of the turning tool.

[0044] Furthermore, in this embodiment, a disc-shaped flange portion 23 is provided at the upper end of the turning tool 23, and bolt holes (bolt holes formed at equal intervals in the circumferential direction) are provided in the flange portion 23. The flange 23 is brought into contact with the lower end surface of the holder 21, and bolts B are fastened to connect the turning tool 23 and the holder 21. This configuration also offers the advantage of being able to change the cutting edge every 90 degrees. Since the machine tool has different rigidity in the X and Y axes, machining becomes possible in the axial direction where rigidity is higher.

[0045] As described above, according to this embodiment, it is possible to provide a machine tool equipped with a configuration for fixing the rotational movement of a turning tool mounted on the spindle, which can be used for heavy turning with a large turning load.

[0046] It should be noted that the present invention is not limited to the embodiments described above, and various modifications are possible within the scope of its gist. [Explanation of Symbols]

[0047] W…Machine tool 1…bed 2…Y-axis drive unit 3... Table 4…Column 5...Arm 6... Spindle head 7… Magazine 10...Spindle 20…Turning tools 21... Holder 22... Anti-rotation locking piece 22a...Through hole 23... Turning tool 230...Body part 231...Blade part 232...Flange section 232a...First bolt hole 233... protruding part 40… Anti-rotation bracket 41...Vertical piece 42... Pin support base 42a1…Opening 42a2...flow channel hole 42b…Support hole 42b1…Small diameter part 42b2... Stepped section 42b3...Large diameter section 43…Movable pin 43a...hole 43a1...Large diameter section 43a2... Stepped section 43a3…Small diameter part 43b...Cylindrical section 43c...Tapered section 44... Stopper bolt 44a…Head 44b...Shaft part 101, 102… O-ring S... Spring P…Fluid supply pipe

Claims

1. A machine tool having a spindle head equipped with a spindle on which a turning tool is mounted, The turning tool comprises a turning tool and a holder that holds the turning tool and is mounted on the spindle, the holder having a substantially columnar anti-rotation locking piece that protrudes radially outward on its outer circumference, and the anti-rotation locking piece having a through hole. The spindle head is provided with an anti-rotation bracket that fixes the rotational movement of the turning tool. The anti-rotation bracket comprises a pin support base fixed to the lower end of the spindle head, and a movable pin disposed inside a pin support hole provided at the end of the pin support base and slidably supported within the pin support hole. The aforementioned pin support base has a pin support hole that extends vertically on one end, and an opening is formed on the side of the other end, with a flow channel hole formed therein that extends toward and communicates with the pin support hole. A fluid supply pipe is connected to the opening to supply fluid at a predetermined pressure. The movable pin is a substantially hollow cylindrical shape with a hole formed therein that extends axially from its upper end to its lower end, and its tip protrudes downward by a predetermined length from the lower end of the pin support base. The anti-rotation bracket is connected to the turning tool by inserting the tip of the movable pin into the through hole of the anti-rotation locking piece provided in the holder of the turning tool mounted on the spindle, thereby fixing the rotational movement of the turning tool. A machine tool characterized in that the fluid supplied from the fluid supply pipe flows through the opening and the flow path hole into the hole of the movable pin installed in the pin support hole, and the movable pin is biased downward by the fluid.

2. The machine tool according to claim 1, characterized in that the through hole of the anti-rotation locking piece is tapered, the movable pin is able to move vertically by a spring provided in the pin support hole of the pin support base, and has a tapered portion formed on its tip side, and when the tapered portion at the tip of the movable pin is inserted into the through hole of the anti-rotation locking piece, the tapered portion and the inner circumferential surface of the tapered shape of the through hole come into contact surface contact.

3. The turning tool comprises a body portion, a flange portion formed on the upper surface of the body portion, and a cutting edge portion mounted below the body portion. The body portion is formed in a substantially cylindrical shape, and at its lower end is a blade mounting portion with a cross-section of approximately 3 / 4 circular, and the blade portion is attached to the blade mounting portion. The flange portion has a plurality of first bolt holes formed around its center at equal intervals in the circumferential direction. The holder constituting the turning tool is formed in a substantially cylindrical shape, and a second bolt hole corresponding to the first bolt hole of the flange portion is provided on its lower end surface. The turning tool is connected to the holder by bringing the upper surface of the flange portion into contact with the lower end surface of the holder, and by inserting bolts into the first bolt hole and the second bolt hole and fastening the bolts, as described in claim 1 or 2.

Images