Machine tool

Abstract

In order to provide a machine tool that does not require ensuring a large space around the tool unit and does not limit the rotation angle of the tool unit, an automatic lathe (100) has a front spindle (20) for holding a workpiece (W) and a turret (31). The circumferential surface of the turret (31) is divided into a plurality of turret surfaces (31n, 31c, ……, 31k), and tools (40, 61, 62, 63, 64, 65) are mounted on these turret surfaces (31n, 31c, ……, 31k). The workpiece (W) is machined using any tool selected by rotating around the Z axis. The distance between at least one turret surface (31n) of the turret surfaces of the turret (31) and the Z axis is set to be shorter than the distances between the remaining other turret surfaces (31c to 31k) and the Z axis.

Description

Technical Field

[0001] The present invention relates to a machine tool having a turret. Background Art

[0002] There is known a machine tool having a turret whose circumferential surface is divided into a plurality of mounting surfaces and tool mounting portions are provided on each mounting surface, and a spindle for holding a workpiece (for example, refer to Patent Document 1). The turret of this machine tool is rotatably provided so that a workpiece held by the spindle can be machined by a tool mounted on an arbitrarily selected tool mounting portion.

[0003] In addition, there has also been proposed a machine tool in which a tool unit capable of performing so-called B-axis rotation (rotation about the Y-axis) that can change the angle relative to the spindle is mounted on a tool mounting portion (for example, refer to Patent Document 2).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-225802

[0007] Patent Document 2: Japanese Patent Application Laid-Open No. 2013-226611 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] However, since the tool unit for B-axis rotation rotates about the axis of the mounting surface on which the tool unit is mounted (the Y-axis orthogonal to the mounting surface), in order to prevent the tool unit from interfering with the surroundings (for example, the spindle or the cover), a large space needs to be ensured around it.

[0010] In addition, for a machine tool that cannot ensure such a large space, it is necessary to limit the rotation angle of the tool unit for B-axis rotation to a range where it does not interfere with the surroundings.

[0011] The present invention has been made in view of the above circumstances, and an object thereof is to provide a machine tool that does not require a large space to be ensured around the tool unit and does not require the rotation angle of the tool unit to be limited.

[0012] Means for Solving the Problems

[0013] The present invention is a machine tool comprising: a spindle for holding a workpiece, and a turret, the turret having a circumferential surface around a rotating axis and an end surface orthogonal to the rotating axis, the circumferential surface being divided into a plurality of mounting surfaces, tools being mounted on the plurality of mounting surfaces, and the workpiece being processed by any of the tools at a rotation position selected by rotating around the rotating axis; the distance between at least one of the mounting surfaces of the turret and the rotating axis being set to be shorter than the distance between the remaining other mounting surfaces and the rotating axis.

[0014] Effects of the Invention

[0015] According to the machine tool of the present invention, it is not necessary to ensure a large space around the tool unit, and it is not necessary to limit the rotation angle of the tool unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a perspective view showing the main structure of an automatic lathe according to one embodiment of the present invention.

[0017] Figure 2 It is a cross-sectional view of the first turret tool post along the Z axis.

[0018] Figure 3 This is a front view of the rear of the first turret tool post as viewed from the front in the Z-axis direction.

[0019] Figure 4 This is a plan view schematically showing how a space including a front spindle, a first turret tool post, a rear spindle, and a portion of a second turret tool post is divided into a processing chamber, and shows a state where the first turret tool post is away from the front spindle.

[0020] Figure 5 This is a plan view schematically showing how a space including a front spindle, a first turret tool post, a rear spindle, and a portion of a second turret tool post is divided into a processing chamber, and shows a state where the first turret tool post is close to the front spindle.

[0021] Figure 6 It is a schematic diagram showing a machinable range that can be machined using a tool when the turret is located in the normal position, the upper position, and the lower position. DETAILED DESCRIPTION

[0022] Hereinafter, an automatic lathe 100 as an example of a machine tool according to the present invention will be described with reference to the drawings.

[0023] Figure 1 1 is a perspective view showing the main structure of an automatic lathe 100 according to an embodiment of the present invention. In the automatic lathe 100 shown in the figure, a front spindle 20 , a first turret tool post 30 , a rear spindle 80 , and a second turret tool post 90 are provided on a bed 10 .

[0024] The front spindle 20 has a collet chuck at its front end, and the bar-shaped workpiece W is held by using this collet chuck (refer to the following Figure 4 , 5 ). The front spindle 20 can rotate about the axis extension direction, i.e., the Z-axis, and thus, the held workpiece W can be rotated about the axis (Z-axis).

[0025] The rear spindle 80 is arranged opposite to the front of the front spindle 20 in the Z-axis direction (closer to the front side in the Z-axis direction than the front end of the front spindle 20 (the direction of the first turret 30)). The rear spindle 80 also has a collet chuck at its front end, and the rear spindle 80 can receive and hold the workpiece W held by the front spindle 20 by using this collet chuck.

[0026] The rear spindle 80 can also rotate about the axis extension direction of its spindle, i.e., the Z-axis, and thus, the held workpiece W can be rotated about the axis (Z-axis).

[0027] The rear spindle 80 is arranged on the rear spindle X-axis sliding part 14b. The rear spindle X-axis sliding part 14b is arranged on the rear spindle Z-axis sliding part 14a. The rear spindle Z-axis sliding part 14a is movable relative to the bed body 10 in the Z-axis direction, and the rear spindle X-axis sliding part 14b is movable relative to the rear spindle Z-axis sliding part 14a in the X-axis direction. The X-axis is set to be inclined by a specified angle (for example, about 60 degrees) with respect to the horizontal plane.

[0028] Thus, the rear spindle 80 is arranged on the bed body 10 so as to be movable in the Z-axis direction and the X-axis direction.

[0029] The first turret 30 is arranged in parallel with the rear spindle 80 in the front of the front spindle 20 in the Z-axis direction (closer to the front side in the Z-axis direction than the front end of the front spindle 20). The first turret 30 machines the workpiece W held by the front spindle 20 (refer to Figure 4 ) or the workpiece W held by the rear spindle 80 by using a specified tool.

[0030] The first turret 30 is arranged on the first turret Y-axis sliding part 16, the first turret Y-axis sliding part 16 is arranged on the first turret X-axis sliding part 15, and the first turret X-axis sliding part 15 is arranged on the first turret Z-axis sliding part 17.

[0031] The first turret Z-axis sliding part 17 is arranged on the bed body 10 so as to be movable along the Z-axis direction. The first turret X-axis sliding part 15 is arranged on the first turret Z-axis sliding part 17 so as to be movable along the X-axis direction orthogonal to the Z-axis direction. The first turret Y-axis sliding part 16 is arranged on the first turret X-axis sliding part 15 so as to be movable along the Y-axis direction orthogonal to the Z-axis direction and the X-axis direction.

[0032] By moving the first turret tool rest 30 relative to the workpiece W held by the front spindle 20 and protruding from the front end of the front spindle 20 in the X-axis direction by moving the first turret tool rest X-axis sliding part 15 relative to the first turret tool rest Z-axis sliding part 17 in the X-axis direction, and by moving the first turret tool rest 30 relative to the workpiece W held by the front spindle 20 and protruding from the front end of the front spindle 20 in the Y-axis direction by moving the first turret tool rest Y-axis sliding part 16 relative to the first turret tool rest X-axis sliding part 15 in the Y-axis direction. The same applies to the workpiece W held by the rear spindle 80 and protruding from the front end of the rear spindle 80.

[0033] The second turret tool rest 90 is disposed opposite to the front side in the Z-axis direction of the rear spindle 80 (closer to the front side in the Z-axis direction than the front end of the rear spindle 80). The second turret tool rest 90 performs machining on the workpiece W held by the front spindle 20 or the workpiece W held by the rear spindle 80 using a tool.

[0034] The second turret tool rest 90 is provided on the second tool rest tilt Y-axis sliding part 13, the second tool rest tilt Y-axis sliding part 13 is provided on the second tool rest X-axis sliding part 12, and the second tool rest X-axis sliding part 12 is provided on the second tool rest Z-axis sliding part 11.

[0035] The second tool rest Z-axis sliding part 11 is movably provided along the Z-axis direction on the bed 10. The second tool rest X-axis sliding part 12 is provided on the second tool rest Z-axis sliding part 11 so as to be movable along the X-axis direction. The second tool rest tilt Y-axis sliding part 13 is provided on the second tool rest X-axis sliding part 12 so as to be movable along an inclined Y-axis direction that is orthogonal to the Z-axis direction and intersects the Y-axis at a predetermined angle.

[0036] By moving the second tool rest X-axis sliding part 12 relative to the second tool rest Z-axis sliding part 11 in the X-axis direction, the second turret tool rest 90 moves relative to the workpiece held by the rear spindle 80 and protruding from the front end of the rear spindle 80 in the X-axis direction, and by moving the second tool rest tilt Y-axis sliding part 13 relative to the second tool rest X-axis sliding part 12 in the inclined Y-axis direction, the second turret tool rest 90 moves relative to the workpiece W held by the rear spindle 80 and protruding from the front end of the rear spindle 80 in the inclined Y-axis direction.

[0037] In addition, by combining the movement of the second tool rest tilt Y-axis sliding part 13 in the inclined Y-axis direction with the movement of the second tool rest X-axis sliding part 12 in the X-axis direction, the second turret tool rest 90 can be moved as if it is moving in the Y-axis direction.

[0038] Figure 2 is a sectional view along the Z-axis of the first turret tool rest 30, Figure 3It is a front view of observing the rear of the first turret tool rest 30 from the front in the Z-axis direction.

[0039] As Figure 2 shown, the first turret tool rest 30 has a main body portion 35, a turret 31, and an extension portion 39. The main body portion 35, the turret 31, and the extension portion 39 are arranged in this order along the Z-axis direction facing forward.

[0040] The main body portion 35 has a rotation shaft 36a extending in the Z-axis direction and a rotation axis 36b coaxial with the rotation shaft 36a. Both the rotation shaft 36a and the rotation axis 36b are rotatable about their axes. The rotation shaft 36a and the rotation axis 36b rotate independently.

[0041] The rotation shaft 36a rotates about the Z-axis to cause a rotary tool such as a drill bit mounted on the turret 31 to rotate about the axis of the rotary tool.

[0042] The rotation axis 36b is formed as a tubular shape disposed on the outer side in the radial direction of the rotation shaft 36a. The rotation axis 36b can rotate the turret 31 relative to the main body portion 35 about the Z-axis by rotating about its axis.

[0043] As Figure 2 、 3 shown, when viewed from the front in the Z-axis direction, the outer shape of the turret 31 is formed as a prism shape. The turret 31 can be rotatably mounted on the main body portion 35 by rotating the rotation axis 36b about the Z-axis in a state where the axis of the prism is along the Z-axis.

[0044] On the front end face 31z of the turret 31 that is orthogonal to the rotation axis 36b and is on the front side in the Z-axis direction, an extension portion 39 that protrudes in the Z-axis direction from the front end face 31z is fixed. The extension portion 39 rotates integrally with the turret 31 about the rotation axis 36b. A rotation motor 38, which is a power source for rotating a later-described rotary tool unit 40, is provided inside the extension portion 39.

[0045] The circumferential surface of the prism of the turret 31 is divided into ten flat turret faces 31n, 31c, 31d, 31e, 31f, 31g, 31h, 31i, 31j, 31k. The circumferential lengths of the turret faces 31c to 31k are equal, and in addition, the dimensions from the rotation center (Z-axis) of the turret 31 are also equal.

[0046] On the other hand, compared with the other turret faces 31c to 31k, the turret face 31n has a longer circumferential dimension and a shorter dimension from the rotation center (Z-axis) of the turret 31.

[0047] Here, we will explain in detail one turret surface 31n, which differs from the other nine turret surfaces 31c to 31k. Generally speaking, to ensure uniform weight balance around the rotation axis, all turret surfaces are designed to have equal circumferential dimensions and dimensions from the rotation center. In other words, a typical turret is formed into a regular polygonal prism.

[0048] The basic structure of the turret 31 of this embodiment is also, when forming Figure 3 When the turret surface 31n is replaced by three imaginary turret surfaces 31a, 31b, and 31m indicated by two-dot chain lines, they form a regular dodecagonal prism shape together with the other nine turret surfaces 31c to 31k.

[0049] The axial lengths of the three imaginary turret surfaces 31a, 31b, and 31m are equal to those of the other nine turret surfaces 31c to 31k, and the dimensions from the rotation center (Z axis) of the turret 31 are also equal to those of the other nine turret surfaces 31c to 31k.

[0050] That is, the turret 31 of the present embodiment has a single flat turret surface 31n instead of three turret surfaces formed between the turret surface 31k and the turret surface 31c in a typical turret having a virtual regular dodecagonal prism shape.

[0051] Therefore, from a morphological point of view, with a general turret in the shape of a regular dodecagonal prism as a reference, the turret 31 of this embodiment can be expressed as three turret surfaces 31m, 31a, and 31b that are continuous in the circumferential direction of the prism are cut off by a plane, so that the cut plane forms a single turret surface 31n.

[0052] However, the turret 31 of this embodiment is merely an assumed shape with a cutout, with respect to the outer shape based on a regular dodecagonal prism. In reality, the turret is not formed into a regular dodecagonal prism and then a portion of the regular dodecagon is cut out to form a decagonal prism. Alternatively, as described above, the turret may be formed into a regular dodecagonal prism and then a portion of the regular dodecagon is cut out to form a decagonal prism.

[0053] Of the ten turret surfaces 31n, 31c, and 31k, nine turret surfaces 31c and 31k are mounted with tool holders 61, 62, 63, 64, and 65. Tools such as cutting tools, indicated by two-dot chain imaginary lines, are mounted on the tool holders 61, 62, 63, 64, and 65. Tools other than cutting tools can also be mounted.

[0054] The first turret tool holder 30 moves in the X-axis direction with the help of the first tool holder X-axis sliding part 15, so that the first tool holder Y-axis sliding part 16 moves in the Y-axis direction, and the first tool holder Z-axis sliding part 17 moves in the Z-axis direction, so that the turret 31 rotates around the rotation axis 36b, and the tool installed on the turret surface at the selected rotation position contacts the workpiece W held and rotated by the front spindle 20, thereby allowing the tool to process the workpiece W.

[0055] An extended turret surface 39a, which is connected to the turret surface 31n, is formed on an extension portion 39 that protrudes from the front end surface 31z of the turret 31 toward the front spindle 20 in the Z-axis direction. Extended turret surface 39a is formed on the same plane as turret surface 31n, extending turret surface 31n toward the front spindle 20 in the Z-axis direction of the turret 31, and is the surface of extension portion 39.

[0056] Furthermore, a rotating tool unit 40 is installed across the turret surface 31n and the extended turret surface 39a. Specifically, the rotating tool unit 40 is mounted at a position offset further toward the turret front end surface 31z than the tools mounted on the other turret surfaces. The rotating tool unit 40 is rotatable about an axis B perpendicular to the turret surface 31n and the extended turret surface 39a. Axis B is parallel to the Y-axis.

[0057] The rotation motor 38 provided inside the extension portion 39 rotates the rotation member 37b provided inside the extension portion 39 about the axis B, thereby rotating the rotary tool unit 40 about the axis B. That is, the rotary tool unit 40 is a so-called B-axis rotating tool unit.

[0058] The rotary tool unit 40 is constantly connected to the rotary shaft 36a and the rotary shaft 37a provided in the extension portion 39, and rotates the rotary tool 42 around the axis C0 of the rotary tool 42 via a transmission mechanism 41 constantly connected to the rotary shaft 37a.

[0059] Thus, the rotary tool unit 40 can process the workpiece W held by the front spindle 20 or the back spindle 80 by so-called B-axis rotation.

[0060] In the automatic lathe 100 configured as described above, the rotary tool unit 40 for B-axis rotation is mounted on turret surface 31n and extended turret surface 39a, which are configured to have a shorter dimension (distance) from the Z-axis, the rotation center of turret 31, than the other turret surfaces 31c to 31k. As a result, turret surface 31n is configured to have a longer dimension in the circumferential direction of turret 31 than the other turret surfaces 31c to 31k.

[0061] Therefore, compared with the rotary tool units 40 provided on the other turret surfaces 31c to 31k, a longer distance can be ensured between the rotary tool unit 40 provided on the turret surface 31n (and the extended turret surface 39a) and the tools provided on the adjacent turret surfaces.

[0062] That is, as Figure 3 shown, when the rotary tool unit 40 is provided on the turret surface 31n, the adjacent turret surfaces to the turret surface 31n are the turret surfaces 31c and 31k. On the other hand, when the rotary tool unit 40 is provided on, for example, the other turret surface 31e, the adjacent turret surfaces to the turret surface 31e are the turret surfaces 31d and 31f.

[0063] Moreover, the distance between the rotary tool unit 40 when provided on the turret surface 31n and the tools 61 and 65 provided on the adjacent turret surfaces 31c and 31k is significantly longer than the distance between the rotary tool unit 40 when provided on the turret surface 31e and the tool 62 provided on the adjacent turret surfaces 31d and 31f.

[0064] Therefore, in the automatic lathe 100 according to the present embodiment, compared with the case of the rotary tool unit 40 provided on the other turret surfaces 31c to 31k, a sufficient clearance can be ensured around the rotary tool unit 40 provided on the turret surface 31n (and the extended turret surface 39a) with respect to the tools 61 and 65 provided on the adjacent turret surfaces 31c and 31k. In addition, there is no need to limit the rotation range of the rotary tool unit 40.

[0065] In addition, the automatic lathe 100 has a partitioned machining chamber in order to limit the splash range of chips generated by machining the workpiece W using the rotary tool 42, and in order to limit the splash range of the coolant sprayed for the purpose of cooling the heat of the workpiece W and the rotary tool 42 generated by cutting, or reducing the friction between the workpiece W and the rotary tool 42.

[0066] Figure 4 It is a top view schematically showing a case where a space including a part of each of the front spindle 20, the first turret tool rest 30, the rear spindle 80, and the second turret tool rest 90 is partitioned into a machining chamber, showing a state where the first turret tool rest 30 is away from the front spindle 20.

[0067] Figure 5 It is a top view schematically showing a case where a space including a part of each of the front spindle 20, the first turret tool rest 30, the rear spindle 80, and the second turret tool rest 90 is partitioned into a machining chamber, showing a state where the first turret tool rest 30 is close to the front spindle 20.

[0068] For example Figure 4As shown, the workpiece W held by the front spindle 20 , the extension portion 39 to which the rotary tool unit 40 is mounted, and the turret 31 are arranged inside the partitioned processing chamber.

[0069] In a structure that limits the splashing range of chips or coolant as much as possible, the partitions 51 and 52 that divide the processing chamber are arranged directly behind the turret 31 in the Z-axis direction (the position closest to the turret 31 behind the turret 31 when the front spindle 20 side is regarded as the front).

[0070] If the rotary tool unit 40 is provided on the normal turret surfaces 31 c to 31 k of the turret 31 as in the related art, the rotary tool unit 40 may interfere with the partition plate 51 and the like when the rotary tool unit 40 rotates along the B axis.

[0071] However, in the automatic lathe 100 of this embodiment, the rotating tool unit 40 is arranged at a position that straddles the turret surface 31n and the extended turret surface 39a, and is therefore arranged biased (offset) toward the front spindle 20 side (front end surface 31z side) in the Z-axis direction compared to the case where it is only arranged on the turret surface 31n.

[0072] As a result, a larger distance (dimension along the Z-axis direction) between the rotary tool unit 40 and the partition plate 51 located behind the turret 31 can be ensured compared to the case where the rotary tool unit 40 is provided on the normal turret surfaces 31 c to 31 k .

[0073] Therefore, according to the automatic lathe 100 of this embodiment, compared with the case where the rotating tool unit 40 is set on other turret surfaces 31c~31k, the gap between the partitions 51 and 52 can be fully ensured around the rotating tool unit 40 set on the turret surface 31n and the extended turret surface 39a. In addition, there is no need to limit the rotation range of the rotating tool unit 40.

[0074] Furthermore, since the first turret tool post 30 is movable in the X-axis direction, the partition plates 51 and 52 connected to the first turret tool post 30 along the X-axis direction are configured to expand and contract as the first turret tool post 30 moves in the X-axis direction.

[0075] That is, in Figure 4 In the figure, the partition 52 arranged above the first turret tool holder 30 in the X-axis direction is arranged in a state where the partition pieces 52a and 52b divided into two pieces in the X-axis direction are overlapped and contracted, and the partition 51 arranged below the first turret tool holder 30 in the X-axis direction is arranged in a state where the partition pieces 51a, 51b, and 51c divided into three pieces in the X-axis direction are staggered and extended in positions in the X-axis direction.

[0076] Moreover, if Figure 5As shown, when the first turret tool holder 30 moves downward in the X-axis direction as shown in the figure, the two partition plates 52a and 52b arranged on the upper side in the X-axis direction are in a state where their positions in the X-axis direction are staggered with each other and the length of the upper side in the X-axis direction is extended, thereby ensuring the division state achieved by the partition plate 52.

[0077] On the other hand, the three partition plates 51 a , 51 b , and 51 c arranged on the lower side in the X-axis direction are overlapped with each other and the length of the lower side in the X-axis direction is reduced, thereby ensuring the partitioning state achieved by the partition plates 52 .

[0078] Regarding the automatic lathe 100 of this embodiment, the relationship between the first turret tool rest 30 and the workpiece W held by the front spindle 20 or the workpiece W held by the back spindle 80 is mainly explained, and the second turret tool rest 90 for processing the workpiece W held by the back spindle 80 or the workpiece W held by the front spindle 20 can be constructed to be the same as the first turret tool rest 30.

[0079] In the automatic lathe 100 of this embodiment, the rotating tool unit 40 for performing B-axis rotation can also be set so as not to cross the turret surface 31n and the extended turret surface 39a. The rotating tool unit 40 can be not hung on the turret surface 31n but only set on the extended turret surface 39a, or it can be set only on the turret surface 31n.

[0080] That is, in the automatic lathe 100, the rotating tool unit 40 that performs B-axis rotation only needs to be installed on at least the turret surface 31n (or the extended turret surface 39a), and the size (distance) of the turret surface 31n (or the extended turret surface 39a) from the rotation center of the turret 31, that is, the Z axis, is set to be shorter than the other turret surfaces 31c~31k.

[0081] In addition, in the case of a structure in which the rotating tool unit 40 is only provided on the turret surface 31n, the center of rotation of the rotating tool unit 40 (axis B) can be the same as the installation position of the tool installed on other turret surfaces 31c~31k, but it is preferred that the center of rotation of the rotating tool unit 40 (axis B) is located at a position closer to the front spindle 20 side than the installation position of the tool installed on other turret surfaces 31c~31k in the Z-axis direction.

[0082] Figure 6 It is a schematic diagram showing the processable range that can be processed using the rotating tool 42 when the turret 31 is located in the general position P1 (equivalent to the selected rotation position), in the upper position P2 (equivalent to a position different from the selected rotation position), and in the lower position P3 (equivalent to a position different from the selected rotation position).

[0083] like Figure 6As shown, in the automatic lathe 100 of this embodiment, when the workpiece is processed using the rotating tool 42 of the rotating tool unit 40, the range at the general position P1 that the rotating tool 42 can reach by moving the first tool holder X-axis sliding part 15 and the first tool holder Y-axis sliding part 16, that is, the processing range, is the range S1 shown by the solid line.

[0084] On the other hand, the range at the upper position P2 reached by rotating the turret 31 upward, which can be reached by the rotating tool 42 by moving the first tool holder X-axis sliding part 15 and the first tool holder Y-axis sliding part 16, is the processing range, which is shown by the dotted line S2. The range at the lower position P3 reached by rotating the turret 31 downward, which can be reached by the rotating tool 42 by moving the first tool holder X-axis sliding part 15 and the first tool holder Y-axis sliding part 16, is the processing range, which is shown by the double-dotted line S3.

[0085] Therefore, according to the automatic lathe 100 of this embodiment, if the turret 31 can rotate the rotary tool 42 at the upper position P2 and the lower position P3 in addition to the normal position P1, the machinable range can be expanded from the range S1 to the range S2-S1-S3.

[0086] In order to rotate the rotating tool 42 also at the upper position P2 and the lower position P3, the rotating shaft 36a and the rotating shaft 37a only need to be always connected when the turret surface 31n is configured at the bottom of the turret 31 (the bottom in the Y-axis direction).

[0087] In addition, compared with the case of processing the workpiece within the range S1 at the general position P1, the inclination of the rotating tool 42 relative to the workpiece is different at the upper position P2 and the lower position P3, and the control unit of the automatic lathe 100 adjusts the phase of the workpiece relative to the rotating tool 42 by rotating the front spindle 20 corresponding to the inclination of the rotating tool 42 (offsetting the inclination). As a result, the workpiece can be processed in a state where the inclination of the rotating tool 42 relative to the workpiece is offset, just like the workpiece is processed at the general position P1.

[0088] By rotating the turret 31 to the upper position P2 and the lower position P3, the distance between the workpiece W and the front end of the rotary tool 42 can be increased compared to the distance at the normal position P1. Therefore, a rotary tool 42 having a longer dimension along the C0 axis can be used. By using a rotary tool 42 having a longer dimension along the C0 axis, a hole penetrating the workpiece W in the radial direction can be drilled.

[0089] The machine tool of the present invention is not limited to an automatic lathe. In addition, in the machine tool of the present invention, the tool mounted on the turret surface whose distance from the turret's rotation center is set shorter than that of other turret surfaces does not need to be a rotary tool unit that performs B-axis rotation.

[0090] In addition, in the machine tool of the present invention, the number of turret surfaces shorter than the other turret surfaces from the rotation center of the turret is not limited to one, but may be two or three. The machine tool of the present invention is not limited to having ten turret surfaces.

[0091] As mentioned above, although embodiment of the present invention was described in detail using drawings, the embodiment is only an example of the present invention, and the present invention is not limited to the above-mentioned embodiment.

[0092] Cross-references between related applications

[0093] This application claims priority based on Japanese Patent Application No. 2020-139161 filed with the Japan Patent Office on August 20, 2020, the entire disclosure of which is incorporated herein by reference.

Claims

1. A machine tool, wherein, comprising: a main spindle for holding a workpiece, and a turret having a peripheral surface around a rotation axis and an end surface orthogonal to the rotation axis, the peripheral surface being divided into a plurality of mounting surfaces, tools being mounted on the plurality of mounting surfaces, and at a rotation position selected by rotating around the rotation axis, the workpiece being machined by any one of the tools; at least one of the mounting surfaces of the turret has a larger gap between the tools provided on the adjacent mounting surfaces than the remaining other mounting surfaces, and the distance between the at least one mounting surface and the rotation axis is set shorter than the distance between the other mounting surfaces and the rotation axis.

2. The machine tool according to claim 1, wherein, The tool mounted on the mounting surface whose distance from the rotation axis is set shorter than that of the other mounting surfaces is mounted at a position more offset toward the end surface side than the tool mounted on the other mounting surfaces.

3. The machine tool according to claim 1 or 2, wherein The tool mounted on the mounting surface whose distance from the rotation axis is set shorter than that of the other mounting surfaces is a rotary tool that rotates around an axis orthogonal to the mounting surface.

4. The machine tool according to claim 3, wherein the turret is movable freely in a plane orthogonal to the axial direction of the main spindle, the rotary tool mounted on the mounting surface whose distance from the rotation axis is set shorter than that of the other mounting surfaces is set to be rotatable in a state where the turret is rotated to a position different from the rotation position, the main spindle is rotated corresponding to the inclination of the rotary tool in a state after the turret is rotated, and the phase of the workpiece is adjusted.

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