Chuck mechanism of lathe, workpiece holding device, and lathe

Abstract

To provide a chuck mechanism of a lathe, a workpiece holding device, and a lathe capable of suppressing vibration of a rotary element when the rotary element including a chuck and a toggle is rotated.SOLUTION: A chuck mechanism of a lathe includes a cylinder, a piston disposed inside the cylinder, a chuck that holds a workpiece by opening and closing movement and is rotatable about a first axis, a toggle that is disposed inside the piston, is rotatable about the first axis, and swings in accordance with movement of the piston, a draw tube that is rotatable about the first axis, is movable along the first axis, and converts swinging movement of the toggle into opening and closing movement of the chuck, and an elastic body disposed between the cylinder and the piston.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a chuck mechanism for a lathe, a workpiece holding device, and a lathe. [Background technology]

[0002] 2. Description of the Related Art Lathes having a chuck mechanism for holding a workpiece are known.

[0003] As a related technique, Patent Document 1 discloses a sliding headstock lathe. The sliding headstock lathe described in Patent Document 1 has a bed, a hollow spindle, the headstock, a spindle rotating device that rotates and drives the spindle, a guide bush that grips the workpiece, a guide bush opening and closing mechanism that opens and closes the guide bush, a hollow material feed shaft that is provided within the spindle and is movable in the axial direction, a chuck for gripping the workpiece that is provided at the tip of the material feed shaft, a chuck opening and closing mechanism that opens and closes the chuck, a headstock moving device that moves the headstock, and a material feed shaft moving device that moves the material feed shaft. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2-232104 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a chuck mechanism for a lathe, a workpiece holding device, and a lathe that can suppress vibration of a rotating element including a chuck and a toggle when the rotating element is rotated. [Means for solving the problem]

[0006] In some embodiments, a chuck mechanism for a lathe includes: a cylinder; a piston disposed inside the cylinder; a chuck that holds a workpiece by opening and closing the chuck and is rotatable about a first axis; a toggle disposed inside the piston, that is rotatable about the first axis, and that swings in conjunction with movement of the piston; a draw tube that is rotatable about the first axis, that is movable along the first axis, and that converts the swinging motion of the toggle into the opening and closing motion of the chuck; and an elastic body disposed between the cylinder and the piston.

[0007] In some embodiments, a workpiece holding device includes a chuck that holds a workpiece by opening and closing movement and is rotatable about a first axis, a rotating body including the chuck, a support body including a cylinder and supporting the rotating body rotatably about the first axis, a piston disposed inside the cylinder, an elastic body disposed between the cylinder and the piston, and a rotation drive device that rotates the rotating body about the first axis. The rotating body includes the chuck, a toggle that is disposed inside the piston and oscillates with movement of the piston, and a draw tube that is movable along the first axis and converts the oscillating movement of the toggle into the opening and closing movement of the chuck.

[0008] In some embodiments, a lathe includes a workpiece holding device, a machining head that holds a tool, and a moving device that moves the machining head relative to the workpiece holding device. The workpiece holding device includes a chuck that holds a workpiece by opening and closing and is rotatable about a first axis, a rotating body including the chuck, a support that includes a cylinder and supports the rotating body rotatably about the first axis, a piston disposed inside the cylinder, an elastic body disposed between the cylinder and the piston, and a rotation drive device that rotates the rotating body about the first axis. The rotating body includes the chuck, a toggle that is disposed inside the piston and oscillates with the movement of the piston, and a draw tube that is movable along the first axis and converts the oscillating motion of the toggle into the opening and closing motion of the chuck. [Effects of the Invention]

[0009] The present invention provides a chuck mechanism for a lathe, a workpiece holding device, and a lathe that can suppress vibration of a rotating element including a chuck and a toggle when the rotating element is rotated. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a workpiece holding device according to the first embodiment. [Figure 2] FIG. 2 is a schematic cross-sectional view illustrating the workpiece holding device according to the first embodiment. [Figure 3] FIG. 3 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 5] FIG. 5 is a schematic cross-sectional view showing a part of a workpiece holding device in a first modified example of the first embodiment. [Figure 6] FIG. 6 is a schematic perspective view showing an example of a piston. [Figure 7] FIG. 7 is a schematic cross-sectional view showing an example of a piston. [Figure 8] FIG. 8 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 9] FIG. 9 is a schematic cross-sectional view showing a part of a workpiece holding device in a second modified example of the first embodiment. [Figure 10] FIG. 10 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 11] FIG. 11 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 12] FIG. 12 is a cross-sectional view taken along the arrow DD in FIG. [Figure 13] FIG. 13 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 14] FIG. 14 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 15] FIG. 15 is a schematic perspective view showing an example of a collet. [Figure 16] FIG. 16 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 17] FIG. 17 is a schematic cross-sectional view illustrating the workpiece holding device according to the first embodiment. [Figure 18] FIG. 18 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 19] FIG. 19 is a schematic cross-sectional view showing a part of the workpiece holding device in the first embodiment. [Figure 20] FIG. 20 is a schematic cross-sectional view illustrating a workpiece holding device according to a third modified example of the first embodiment. [Figure 21] FIG. 21 is a diagram schematically illustrating a lathe according to the second embodiment. [Figure 22] FIG. 22 is a block diagram illustrating an example of a hardware configuration of the control device. [Figure 23] FIG. 23 is a block diagram illustrating an example of a hardware configuration of the control device. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, a lathe chuck mechanism 1, a workpiece holding device 10, and a lathe 100 according to an embodiment will be described with reference to the drawings. In the following description of the embodiment, parts and members having the same functions are given the same reference numerals, and repeated description of parts and members given the same reference numerals will be omitted.

[0012] (First embodiment) A chuck mechanism 1 for a lathe and a workpiece holding device 10 according to a first embodiment will be described with reference to FIGS. 1 to 20. FIGS. 1 and 2 are schematic cross-sectional views showing the workpiece holding device 10 according to the first embodiment. FIGS. 3 and 4 are schematic cross-sectional views showing a portion of the workpiece holding device 10 according to the first embodiment. FIG. 5 is a schematic cross-sectional view showing a portion of the workpiece holding device 10 according to a first modified example of the first embodiment. FIG. 6 is a schematic perspective view showing an example of a piston 3. FIG. 7 is a schematic cross-sectional view showing an example of a piston 3. FIG. 8 is a schematic cross-sectional view showing a portion of the workpiece holding device 10 according to the first embodiment. FIG. 9 is a schematic cross-sectional view showing a portion of the workpiece holding device 10 according to a second modified example of the first embodiment. FIG. 10 is a schematic cross-sectional view showing a portion of the workpiece holding device 10 according to the first embodiment. FIG. 11 is a schematic cross-sectional view showing a portion of the workpiece holding device 10 according to the first embodiment. FIG. 12 is a cross-sectional view taken along the line DD in FIG. 1. FIG. 13 is a schematic cross-sectional view showing a portion of the work holding device 10 in the first embodiment. FIG. 14 is a schematic cross-sectional view showing a portion of the work holding device 10 in the first embodiment. FIG. 15 is a schematic perspective view showing an example of a collet 41. FIG. 16 is a schematic cross-sectional view showing a portion of the work holding device 10 in the first embodiment. FIG. 17 is a schematic cross-sectional view showing the work holding device 10 in the first embodiment. FIGS. 18 and 19 are schematic cross-sectional views showing a portion of the work holding device 10 in the first embodiment. FIG. 20 is a schematic cross-sectional view showing the work holding device 10 in a third modified example of the first embodiment.

[0013] As illustrated in FIG. 1, the chuck mechanism 1 of the lathe in the first embodiment includes a cylinder 25, a piston 3, a chuck 40, a toggle 50, a draw tube 44, and an elastic body 6.

[0014] A piston 3 is disposed inside the cylinder 25 .

[0015] In the example shown in FIG. 1, the piston 3 is movable in a direction along the first axis AX (more specifically, in a direction along the rotation axis of the spindle 71).

[0016] 1 and 2, the chuck 40 can hold the workpiece W by opening and closing the chuck 40. The chuck 40 can also rotate around a first axis AX.

[0017] The toggle 50 is disposed inside the piston 3. The toggle 50 is rotatable about a first axis AX. As illustrated in FIGS. 1 and 2, the toggle 50 swings in accordance with the movement of the piston 3.

[0018] The draw tube 44 is rotatable about the first axis AX and movable along the first axis AX. The draw tube 44 converts the swinging motion of the toggle 50 into an opening and closing motion of the chuck 40. More specifically, the draw tube 44 converts the swinging motion of the toggle 50 into a motion that moves the inner surface of the chuck 40 (more specifically, the inner surface 410t of the chuck's cylindrical portion 410 illustrated in FIG. 15 ) closer to the first axis AX so that the workpiece W is held by the inner surface of the chuck 40.

[0019] The elastic body 6 is disposed between the cylinder 25 and the piston 3 .

[0020] In the lathe chuck mechanism 1 of the first embodiment, the toggle 50 is disposed inside the piston 3, and the elastic body 6 is disposed between the cylinder 25 and the piston 3. Therefore, when the rotating elements including the chuck 40 and the toggle 50 are rotated around the first axis AX, vibration of the rotating elements is suppressed by the elastic body 6 disposed between the cylinder 25 and the piston 3.

[0021] The workpiece holding device 10 in the first embodiment includes a rotating body RB including a chuck 40, a piston 3, an elastic body 6, a support body 2, and a rotation drive device 77.

[0022] The chuck 40, the piston 3, and the elastic body 6 have already been explained, so repeated explanations of the chuck 40, the piston 3, and the elastic body 6 will be omitted.

[0023] The support body 2 includes the above-mentioned cylinder 25. The support body 2 also supports a rotating body RB including the chuck 40, the toggle 50, and the draw tube 44 so as to be rotatable about a first axis AX.

[0024] The rotation drive device 77 rotates the rotating body RB around the first axis AX. In the example shown in FIG. 1, the rotation drive device 77 has a stator 77a disposed on the support body 2 and a rotor 77b disposed on the rotating body RB (more specifically, the spindle 71). The rotation drive device 77 is a device that rotates the rotating body RB by electromagnetic action. Alternatively, the rotation drive device 77 may be a device that rotates the rotating body RB using a transmission belt or the like.

[0025] The workpiece holding device 10 in the first embodiment has the same effects as the chuck mechanism 1 of the lathe in the first embodiment.

[0026] (Optional configuration) Next, optional additional configurations that can be employed in the chuck mechanism 1 of the lathe in the first embodiment or the workpiece holding device 10 in the first embodiment will be described with reference to FIGS.

[0027] (Spindle 71) The spindle 71 is rotated about a first axis AX by a rotary drive device 77. In the example shown in Fig. 1, the spindle 71 is formed of a hollow shaft extending along the first axis AX. In the example shown in Fig. 1, a rotor 77b is attached to the spindle 71.

[0028] (Arrangement relationship between the toggle 50 and the piston 3) 4, the piston 3 and the toggle 50 are arranged on a first plane PL1 perpendicular to the first axis AX. In this case, the radial force acting on the toggle 50 (more specifically, the force perpendicular to the first axis AX, which is the axis of rotation) is suitably transmitted to the piston 3, and the radial force acting on the piston 3 is transmitted to the elastic body 6. In this way, vibration of the rotating body including the toggle 50 in the radial direction is effectively suppressed.

[0029] 4, the elastic body 6, the piston 3, and the toggle 50 are arranged on a first plane PL1 perpendicular to the first axis AX. In this case, the radial force acting on the toggle 50 (more specifically, the force perpendicular to the first axis AX, which is the axis of rotation) is suitably transmitted to the piston 3, and the radial force acting on the piston 3 is suitably transmitted to the elastic body 6. In this way, vibration of the rotating body including the toggle 50 in the radial direction is more effectively suppressed.

[0030] In the example shown in FIG. 4, a plurality of elastic bodies including a first elastic body 6a and a second elastic body 6b are arranged between the cylinder 25 and the piston 3. A third elastic body 6c may be arranged between the cylinder 25 and the piston 3. As illustrated in FIG. 4, the first elastic body 6a (more specifically, the first elastic ring 61a), the piston 3, and the toggle 50 may be arranged on a first plane PL1. Furthermore, a second elastic body 6b (more specifically, the second elastic ring 61b), which is separate from the first elastic body 6a, the piston 3, and the toggle 50 may be arranged on a second plane PL2 parallel to the first plane PL1. In the example shown in FIG. 4, the piston 3 is arranged on a third plane PL3 that passes through the third elastic body 6c (more specifically, the third elastic ring 61c) and is perpendicular to the first axis AX, but the toggle 50 is not arranged on the third plane PL3. Alternatively, the toggle 50 may be arranged on the third plane PL3.

[0031] 1, a direction parallel to the first axis AX and a direction from the toggle 50 toward the chuck 40 is defined as a first direction DR1, and a direction opposite to the first direction DR1 is defined as a second direction DR2. In FIG. 1, the first direction DR1 is a direction from the base end 71b of the spindle 71 toward the tip end 71a of the spindle 71, and the second direction DR2 is a direction from the tip end 71a of the spindle 71 toward the base end 71b of the spindle 71.

[0032] In the example (first modified example) shown in FIG. 5 , the piston 3 and the toggle 50 are arranged on a first plane PL1 perpendicular to the first axis AX. A first elastic body 6a is arranged between the cylinder 25 and the piston 3 on the first direction DR1 side of the first plane PL1, and another elastic body (e.g., a third elastic body 6c) is arranged between the cylinder 25 and the piston 3 on the second direction DR2 side of the first plane PL1. In this case, too, a radial force acting on the toggle 50 (more specifically, a force perpendicular to the first axis AX, which is the rotation axis) is suitably transmitted to the piston 3, and a radial force acting on the piston 3 is suitably transmitted to the elastic body 6. As a result, vibration of the rotating body, including the toggle 50, in the radial direction is effectively suppressed. In the example shown in FIG. 5 , for all of the elastic bodies 6 arranged between the cylinder 25 and the piston 3, the piston 3 is arranged on a plane that passes through each elastic body and is perpendicular to the first axis AX, but the toggle 50 is not arranged on this plane. More specifically, the first elastic body 6a and the second elastic body 6b are arranged closer to the first direction DR1 side than the end of the toggle 50 on the first direction DR1 side, and the third elastic body 6c is arranged closer to the second direction DR2 side than the end of the toggle 50 on the second direction DR2 side.

[0033] In the example shown in FIG. 6, the piston 3 is an annular piston 3a. An internal space SP1 is defined by the inner surface of the annular piston 3a. As shown in FIG. 4, the central axis AT of the annular piston 3a substantially coincides with the first axis AX. More specifically, the internal space SP1 of the annular piston 3a is a space defined by a plane PC1 that passes through the end of the annular piston 3a on the first direction DR1 side and is perpendicular to the first axis AX, a plane PC2 that passes through the end of the annular piston 3a on the second direction DR2 side and is perpendicular to the first axis AX, and the inner surface of the annular piston 3a.

[0034] At least a portion of the toggle 50 is disposed in the internal space SP1 defined by the inner surface of the annular piston 3a. In the example shown in FIG. 4, when the pressed portion 52a of the toggle 50 is pressed by the inner surface of the annular piston 3a, the pressed portion 52a is disposed in the internal space SP1 defined by the inner surface of the annular piston 3a. The annular piston 3a efficiently transmits the radial force acting on the toggle 50 to the elastic body 6. In this way, vibration of the rotating body including the toggle 50 in the radial direction is effectively suppressed.

[0035] In the example shown in FIG. 8, the elastic body 6 includes at least one elastic ring 61. In the example shown in FIG. 8, the elastic body 6 includes a first elastic ring 61a, a second elastic ring 61b, and a third elastic ring 61c. The first elastic ring 61a is, for example, a seal ring (such as an O-ring or a dust seal ring). The second elastic ring 61b is, for example, a seal ring (such as an O-ring or a dust seal ring). The third elastic ring 61c is, for example, a seal ring (such as an O-ring or a dust seal ring).

[0036] The first elastic ring 61a, the second elastic ring 61b, and the third elastic ring 61c suitably support the radial force acting on the piston 3 (more specifically, the annular piston 3a), thereby effectively suppressing vibration of the piston 3 and the toggle 50 in the radial direction.

[0037] The first elastic ring 61a is disposed between the second elastic ring 61b and the third elastic ring 61c in the direction along the first axis AX. More specifically, the second elastic ring 61b is disposed closer to the first direction DR1 than the first elastic ring 61a, and the third elastic ring 61c is disposed closer to the second direction DR2 than the first elastic ring 61a.

[0038] 8, the first elastic ring 61a is held by the cylinder 25, and the piston 3 slides against the first elastic ring 61a. The cylinder 25 may have a first annular groove 21v that holds the elastic ring 61 (more specifically, the first elastic ring 61a).

[0039] 8, the second elastic ring 61b is held by the piston 3, and the second elastic ring 61b slides relative to the cylinder 25. The piston 3 may have a second annular groove 31u that holds the elastic ring 61 (more specifically, the second elastic ring 61b).

[0040] 8, the third elastic ring 61c is held by the piston 3, and the third elastic ring 61c slides relative to the cylinder 25. The piston 3 may have a third annular groove 31w that holds the elastic ring 61 (more specifically, the third elastic ring 61c).

[0041] In the example shown in Fig. 8, the first elastic ring 61a is held by the cylinder 25, and the second elastic ring 61b and the third elastic ring 61c are held by the piston 3. Alternatively, as illustrated in Fig. 9, the first elastic ring 61a may be held by the piston 3, and the second elastic ring 61b and the third elastic ring 61c may be held by the cylinder 25. In the example (second modified example) shown in Fig. 9, the first elastic ring 61a is held in a first annular groove 31v formed in the piston 3, the second elastic ring 61b is held in a second annular groove 21u formed in the cylinder 25, and the third elastic ring 61c is held in a third annular groove 21w formed in the cylinder 25.

[0042] In the examples shown in Figures 4, 5, 8, and 9, when the rotating body RB rotates (for example, when the toggle 50, spindle 71, etc. rotate), the elastic body 6 (more specifically, at least one elastic ring 61) suppresses vibration of the piston 3 and the toggle 50 in a direction perpendicular to the first axis AX.

[0043] The elastic ring 61 is made of, for example, rubber. The material of the elastic ring 61 may be a material commonly used for elastic rings (for example, nitrile rubber, fluororubber, or silicone rubber). The material of the elastic ring 61 may be selected in consideration of vibration damping characteristics.

[0044] 10 , toggle 50 is disposed so as to cross internal space SQ1 defined by the inner surface of first elastic ring 61a. Furthermore, spindle 71 and / or draw tube 44 are disposed so as to cross internal space SQ1 defined by the inner surface of first elastic ring 61a. The center of first elastic ring 61a (more specifically, the geometric center of first elastic ring 61a) is located within the internal space of draw tube 44, and more preferably, the center of first elastic ring 61a (more specifically, the geometric center of first elastic ring 61a) is located on first axis AX. The internal space SQ1 defined by the inner surface of the first elastic ring 61a is, more specifically, a space defined by a plane PC3 that passes through the end of the first elastic ring 61a on the first direction DR1 side and is perpendicular to the first axis AX, a plane PC4 that passes through the end of the first elastic ring 61a on the second direction DR2 side and is perpendicular to the first axis AX, and the inner surface 615a of the first elastic ring 61a. The geometric center of the elastic ring refers to the position of the arithmetic mean taken over all points belonging to the elastic ring.

[0045] In the example shown in FIG. 10, the first elastic ring 61a is disposed between the cylinder 25 and the piston 3 so as to surround the toggle 50 over its entire periphery.

[0046] 10 , toggle 50 is disposed so as to cross internal space SQ2 defined by the inner surface of second elastic ring 61b. Furthermore, spindle 71 and / or draw tube 44 are disposed so as to cross internal space SQ2 defined by the inner surface of second elastic ring 61b. The center of second elastic ring 61b (more specifically, the geometric center of second elastic ring 61b) is located within the internal space of draw tube 44, and more preferably, the center of second elastic ring 61b (more specifically, the geometric center of second elastic ring 61b) is located on first axis AX. The internal space SQ2 defined by the inner surface of the second elastic ring 61b is, more specifically, a space defined by a plane PC5 that passes through the end of the second elastic ring 61b on the first direction DR1 side and is perpendicular to the first axis AX, a plane PC6 that passes through the end of the second elastic ring 61b on the second direction DR2 side and is perpendicular to the first axis AX, and the inner surface 615b of the second elastic ring 61b.

[0047] In the example shown in FIG. 10, the second elastic ring 61b is disposed between the cylinder 25 and the piston 3 so as to surround the toggle 50 over its entire periphery.

[0048] 10 , the spindle 71 and / or the draw tube 44 are disposed so as to cross an internal space SQ3 defined by the inner surface of the third elastic ring 61c. The center of the third elastic ring 61c (more specifically, the geometric center of the third elastic ring 61c) is located within the internal space of the draw tube 44, and more preferably, the center of the third elastic ring 61c (more specifically, the geometric center of the third elastic ring 61c) is located on the first axis AX. The internal space SQ3 defined by the inner surface of the third elastic ring 61c is, more specifically, a space defined by a plane PC7 that passes through the end of the third elastic ring 61c on the first direction DR1 side and is perpendicular to the first axis AX, a plane PC8 that passes through the end of the third elastic ring 61c on the second direction DR2 side and is perpendicular to the first axis AX, and an inner surface 615c of the third elastic ring 61c.

[0049] (Piston 3) In the example shown in FIGS. 3 and 4, the piston 3 moves in a direction along the first axis AX (more specifically, in a first direction DR1 or a second direction DR2) while contacting the toggle 50. In FIG. 3, the piston 3 is located at a first position P1, and in FIG. 4, the piston 3 is located at a second position P2. When the piston 3 is located at the second position P2, the workpiece W is held by the chuck 40. When the piston 3 is located at the first position P1, the hold of the workpiece W by the chuck 40 is released. In the example shown in FIGS. 3 and 4, the direction from the first position P1 toward the second position P2 is the same as the second direction DR2.

[0050] In the example shown in Figure 7, the piston 3 has a first part 31 that contacts the elastic body 6 (more specifically, at least one elastic ring 61), a second part 33 that contacts the toggle 50, and a bearing 35 that is arranged between the first part 31 and the second part 33.

[0051] 8, the first portion 31 contacts a plurality of elastic rings 61. More specifically, the first portion 31 contacts each of the first elastic ring 61a, the second elastic ring 61b, and the third elastic ring 61c. In the example shown in FIG. 8, the first portion 31 has annular grooves (e.g., the second annular groove 31u and / or the third annular groove 31w) that hold the elastic rings 61 (e.g., the second elastic ring 61b and / or the third elastic ring 61c).

[0052] The first portion 31 is guided by the cylinder 25 when the piston 3 moves. The first portion 31 has a cylindrical shape. The first portion 31 may be composed of multiple parts. In the example shown in FIG. 7, the first portion 31 is composed of multiple parts including a first annular part 311 and a second annular part 312. In the example shown in FIG. 7, a second annular groove 31u is formed in the outer peripheral surface of the first annular part 311. Furthermore, a third annular groove 31w is formed in the outer peripheral surface of the second annular part 312. In the example shown in FIG. 6, the first annular part 311 and the second annular part 312 are connected to each other by a fixing member BT such as a bolt BT1.

[0053] 7, the first portion 31 has an outer ring support portion 32 that supports the outer ring 36 of the bearing 35. The outer ring support portion 32 may have a first support portion 321 that contacts the front end of the outer ring 36 and a second support portion 322 that contacts the rear end of the outer ring 36. In the example shown in FIG. 7, the first annular component 311 has the first support portion 321, and the second annular component 312 has the second support portion 322.

[0054] The second portion 33 is rotatable relative to the first portion 31 about the first axis AX. More specifically, the second portion 33 rotates about the first axis AX together with the toggle 50. In the example shown in Fig. 7, the second portion 33 is supported by the first portion 31 via a bearing 35 so as to be rotatable about the first axis AX.

[0055] 3 and 4, the second portion 33 moves in a direction along the first axis AX (more specifically, in the first direction DR1 or the second direction DR2) while contacting the toggle 50. In the example shown in Fig. 3 and 4, the second portion 33 functions as a cam that swings the toggle 50.

[0056] 7, the second portion 33 has a cylindrical shape. The central axis of the second portion 33 substantially coincides with the first axis AX. The second portion 33 may be composed of multiple parts.

[0057] 7, the second portion 33 has a first pressing surface 331 (in other words, a tapered pressing surface) whose inner diameter decreases as it moves in the first direction DR1. In the example shown in FIG. 3, when the second portion 33 (more specifically, the first pressing surface 331) moving in a direction along the first axis AX presses the pressed portion 52a of the toggle 50, the toggle 50 swings. In the example shown in FIG. 3, the first pressing surface 331 of the second portion 33 functions as a cam surface 33c that swings the toggle 50.

[0058] As illustrated in FIG. 4 , the second portion 33 may have a second pressing surface 332 that maintains the pressed portion 52a of the toggle 50 in a contracted state. The contracted state refers to a state in which the pressed portion 52a is relatively closer to the first axis AX, and the expanded state refers to a state in which the pressed portion 52a is relatively farther from the first axis AX than in the contracted state. In the example illustrated in FIGS. 3 and 4 , the pressed portion 52a is pressed by the first pressing surface 331 moving in the second direction DR2, causing the pressed portion 52a to approach the first axis AX. As a result, the state of the pressed portion 52a changes from the expanded state (see FIG. 3 ) to the contracted state (see FIG. 4 ). In the example illustrated in FIGS. 3 and 4 , the second pressing surface 332 is disposed closer to the first direction DR1 than the first pressing surface 331.

[0059] 7, the second portion 33 has an inner ring support portion 34 that supports an inner ring 37 of the bearing 35. The inner ring support portion 34 may have a third support portion 341 that contacts the front end of the inner ring 37 and a fourth support portion 342 that contacts the rear end of the inner ring 37. In the example shown in FIG. 7, the part that has the third support portion 341 is screwed into the part that has the fourth support portion 342.

[0060] 7 , the length L2 of the second portion 33 in the direction along the first axis AX is shorter than the length L1 of the first portion 31 in the direction along the first axis AX. The entire second portion 33 may be disposed within an internal space SP2 defined by the inner surface of the first portion 31. More specifically, the end 33f of the second portion 33 on the first direction DR1 side may be located closer to the second direction DR2 than the end 31f of the first portion 31 on the first direction DR1 side, and the end 33e of the second portion 33 on the second direction DR2 side may be located closer to the first direction DR1 than the end 31e of the first portion 31 on the second direction DR2 side.

[0061] The second portion 33 may be guided by a sleeve portion 58 (see FIG. 3) described below when the piston 3 moves.

[0062] The bearing 35 has an outer ring 36, an inner ring 37, and a plurality of rolling elements 38 arranged between the outer ring 36 and the inner ring 37. In the example shown in Fig. 7, the outer ring 36 is arranged in contact with the first portion 31 of the piston 3, and the inner ring 37 is arranged in contact with the second portion 33 of the piston 3.

[0063] 7, the bearing 35 includes a first bearing 35a and a second bearing 35b. Each of the first bearing 35a and the second bearing 35b includes an outer ring 36, an inner ring 37, and a plurality of rolling elements 38 disposed between the outer ring 36 and the inner ring 37.

[0064] The bearing 35 is, for example, a bearing capable of supporting a load in a direction along the first axis AX (in other words, an axial load). The bearing 35 is, for example, an angular contact ball bearing.

[0065] (Toggle 50 and toggle support 56) In the example shown in FIG. 11, the lathe chuck mechanism 1 (or the workpiece holding device 10) includes a toggle 50 (e.g., a first toggle 50a) and a toggle support 56 (more specifically, a toggle support sleeve 56a) that supports the toggle 50 (e.g., the first toggle 50a) so that it can swing.

[0066] The toggle 50 has a pressed portion 52a that is pressed by the piston 3 (more specifically, the cam surface 33c of the piston 3), a fulcrum 54 for the swinging motion, and a pressing portion 55 that presses the draw tube 44. The pressed portion 52a functions as a point of application of force from the piston 3, and the pressing portion 55 functions as a point of action that presses the draw tube 44.

[0067] The pressed portion 52a is formed, for example, by a protruding portion 52 that protrudes from an end of the toggle 50 (more specifically, an end of the toggle 50 on the second direction DR2 side) in a direction away from the first axis AX. The fulcrum 54 is formed, for example, by a convex curved surface 54s that contacts the toggle support member 56. In this case, the toggle support member 56 may have a concave curved surface 57s that contacts the convex curved surface 54s that constitutes the fulcrum 54.

[0068] In the example shown in FIGS. 3 and 4, the pressing portion 55 presses the draw tube 44 in a direction substantially parallel to the first axis AX.

[0069] In the example shown in FIGS. 3 and 4, the pressing portion 55 presses the draw tube 44 in the first direction DR1 in response to the pressed portion 52a being pressed by the second portion 33 of the piston 3.

[0070] More specifically, in the example shown in FIGS. 3 and 4, when the piston 3 moves in the second direction DR2, the second portion 33 of the piston 3 (more specifically, the cam surface 33c of the piston 3) presses the pressed portion 52a of the toggle 50 in a direction approaching the first axis AX. As a result, the pressed portion 52a moves in a direction approaching the first axis AX (see FIG. 4). When the pressed portion 52a moves in a direction approaching the first axis AX, the toggle 50 swings around the fulcrum 54, and the pressing portion 55 of the toggle 50 moves in the first direction DR1. The pressing portion 55 moving in the first direction DR1 presses the draw tube 44 in the first direction DR1. In this way, the draw tube 44 moves in the first direction DR1.

[0071] 3 and 4, by using the toggle 50, it is possible to strongly press the draw tube 44 by using the principle of leverage. More specifically, the toggle 50 has a fulcrum 54, a pressed portion 52a as a point of force application, and a pressing portion 55 as a point of action. Therefore, compared to the case where a piston directly presses the draw tube, the toggle 50 can press the draw tube 44 with a stronger force.

[0072] 2, the draw tube 44 moving in the first direction DR1 moves the sleeve 42 (more specifically, the collet sleeve 42c) in the first direction DR1 against the biasing force of the biasing member 43. As a result, the workpiece W is held by the chuck 40 (more specifically, the collet 41).

[0073] In the example shown in FIG. 12, the chuck mechanism 1 of the lathe (or the workpiece holding device 10) includes three toggles 50 arranged at equal angular intervals around the first axis AX. It goes without saying that the number of toggles 50 included in the chuck mechanism 1 of the lathe (or the workpiece holding device 10) is not limited to three. In the example shown in FIG. 12, the chuck mechanism 1 of the lathe (or the workpiece holding device 10) includes a first toggle 50a, a second toggle 50b, and a third toggle 50c. The shape of the second toggle 50b may be substantially the same as the shape of the first toggle 50a. The shape of the third toggle 50c may be substantially the same as the shape of the first toggle 50a.

[0074] In the example shown in FIG. 11, the toggle 50 has a first arm 511 extending along a first axis AX, a second arm 512 extending away from the first axis AX, and a connecting portion 513 connecting the first arm 511 and the second arm 512.

[0075] The first arm 511 is disposed so as to pass through a groove 57v formed in the flange 57 of the toggle support 56. In addition, a pressed portion 52a is disposed at an end of the first arm 511 (more specifically, at an end on the second direction DR2 side).

[0076] A fulcrum 54 is disposed on the second arm 512. Furthermore, a pressing portion 55 is disposed on the connecting portion 513.

[0077] 11 , a first opening OP1 that allows the first arm 511 to approach the draw tube 44 is formed in the spindle 71. The first opening OP1 formed in the spindle 71 allows the first arm 511 to swing around the fulcrum 54.

[0078] 11 , the toggle support 56 supports the fulcrum 54 of the toggle 50 so that the toggle 50 can swing around the fulcrum 54. The toggle support 56 may have a flange 57 that supports the fulcrum 54 of the toggle 50, and a sleeve portion 58 that extends along the first axis AX. In the example shown in FIG. 11 , the toggle support 56 (more specifically, the sleeve portion 58) has an end portion 58a that contacts the adjustment member 59.

[0079] 11 , a second opening OP2 that allows the first arm 511 to approach the draw tube 44 is formed in the sleeve portion 58. The second opening OP2 formed in the sleeve portion 58 allows the first arm 511 to swing around the fulcrum 54.

[0080] (Adjustment member 59) 11, the lathe chuck mechanism 1 (or workpiece holding device 10) includes an adjustment member 59 that adjusts the relative position of the toggle support 56 (more specifically, the toggle support sleeve 56a) with respect to the spindle 71 in the direction along the first axis AX. In the example shown in FIG. 11, the adjustment member 59 includes a nut 59a that threads onto the end of the spindle 71 on the second direction DR2 side.

[0081] 11, when the adjustment member 59 moves in the first direction DR1, the toggle support 56 pressed by the adjustment member 59 moves in the first direction DR1. When the toggle support 56 moves in the first direction DR1, the entire toggle 50 pressed by the toggle support 56 (more specifically, the flange 57) moves in the first direction DR1.

[0082] 11, the position of the toggle support 56 in the direction along the first axis AX can be adjusted to adjust the size of the inner diameter of the chuck 40 when holding a workpiece. In other words, when the chuck mechanism 1 of the lathe (or the workpiece holding device 10) is equipped with the adjustment member 59, the position of the toggle support 56 in the direction along the first axis AX can be adjusted taking into account the magnitude of the holding force to be applied to the workpiece W, etc.

[0083] In the examples shown in FIGS. 3 and 4 , the piston 3 (more specifically, the second portion 33 of the piston 3) slides against the toggle support 56 (more specifically, the sleeve portion 58) (see arrow AR1). To ensure smooth sliding, a gap generally exists between the two sliding members (for example, a gap exists between the piston 3 and the sleeve portion 58). When the rotor rotates at high speed while the gap exists, the rotor vibrates. In contrast, in the example shown in FIG. 4 , the elastic body 6 (more specifically, the elastic ring 61) is interposed between the cylinder 25 and the piston 3, so that the gap between the piston 3 and the sleeve portion 58 can be eliminated or the size of the gap can be reduced. Thus, when the rotor RB including the second portion 33 of the piston 3, the toggle 50, and the toggle support 56 rotates at high speed, vibration of the rotor RB is suppressed.

[0084] In the example shown in FIG. 11 , when the adjustment member 59 is moved in the first direction DR1, the toggle support 56 (more specifically, the sleeve portion 58) slides against the spindle 71 and / or the second portion 33 of the piston 3 (see arrows AR2 and AR3). To ensure smooth sliding, a gap generally exists between the two sliding members (for example, a gap exists between the sleeve portion 58 and the spindle 71 and / or the second portion 33 of the piston 3). When such a gap exists, the rotating body vibrates when it rotates at high speed. In contrast, in the example shown in FIG. 4 , the elastic body 6 (more specifically, the elastic ring 61) is interposed between the cylinder 25 and the piston 3, so that the gap between the toggle support 56 (more specifically, the sleeve portion 58) and the spindle 71 and / or the second portion 33 of the piston 3 can be eliminated or the size of the gap can be reduced. In this way, when the rotating body RB including the second portion 33 of the piston 3 and the toggle 50 rotates at high speed, vibration of the rotating body RB is suppressed.

[0085] (Draw tube 44) Draw tube 44 is movable in a first direction DR1 and in a second direction DR2 opposite to first direction DR1. In the example shown in FIG. 1 , draw tube 44 is disposed inside spindle 71. The central axis of draw tube 44 substantially coincides with the central axis of spindle 71.

[0086] 1, the tip end 44a of the draw tube 44 is disposed inside the spindle 71, and the base end 44b of the draw tube 44 is disposed inside the spindle 71. In addition, in the example shown in FIG. 12, a plurality of toggles 50 are disposed to surround the draw tube 44.

[0087] 1, when the draw tube 44 is pressed in the first direction DR1 by the pressing portion 55 of the toggle 50, the draw tube 44 moves in the first direction DR1. On the other hand, in the example shown in FIG. 2, when the pressing portion 55 of the toggle 50 moves in the second direction DR2, the biasing force of the biasing member 43 moves the draw tube 44 in the second direction DR2.

[0088] 13, the draw tube 44 has a pressed surface 441s that is pressed in the first direction DR1 by the pressing portion 55 (see FIG. 11) of the toggle 50. In the example shown in FIG. 13, the draw tube 44 has a recess 441 that is recessed in the direction toward the first axis AX, and the pressed surface 441s is disposed in the recess 441. At least a portion of the pressing portion 55 of the toggle 50 can enter the recess 441.

[0089] As illustrated in FIG. 14, the draw tube 44 may have a pressing surface 44s that presses the chuck 40 (more specifically, the sleeve 42 that constitutes a part of the chuck 40).

[0090] (Chuck 40) 14, the chuck 40 includes a collet 41 and a sleeve 42 (more specifically, a collet sleeve 42c). The chuck 40 may include a biasing member 43.

[0091] 14, the sleeve 42 (more specifically, the collet sleeve 42c) is pressed by the draw tube 44. Also, the collet 41 is pressed by the sleeve 42 (more specifically, the collet sleeve 42c).

[0092] In the example shown in FIG. 14, the collet 41 includes a cylindrical portion 410. As illustrated in FIG. 15, at least one slit 410s is formed in the cylindrical portion 410, and the cylindrical portion 410 has an inner surface 410t that holds the workpiece W. The at least one slit 410s allows the cylindrical portion 410 to contract in diameter when the cylindrical portion 410 is pressed toward the first axis AX. Furthermore, as the cylindrical portion 410 contracts in diameter, the inner surface 410t firmly holds the workpiece W. In the example shown in FIG. 15, the at least one slit 410s extends in a direction parallel to the first axis AX.

[0093] In the example shown in FIG. 14, the sleeve 42 (more specifically, the collet sleeve 42c) converts the force received from the draw tube 44 (more specifically, the pressing surface 44s of the draw tube 44) into a force that pushes the collet 41 in a direction toward the first axis AX (more specifically, a force that reduces the diameter of the tubular portion 410 of the collet 41).

[0094] 14, the sleeve 42 (more specifically, the collet sleeve 42c) is disposed inside the spindle 71. The collet 41 is disposed inside the sleeve 42.

[0095] 14, the inner surface of the collet sleeve 42c has a first inclined surface 425c that moves away from the first axis AX as it moves in the first direction DR1, and the outer surface of the collet 41 has a second inclined surface 415c that moves away from the first axis AX as it moves in the first direction DR1. Therefore, when the collet sleeve 42c moves in the first direction DR1, the first inclined surface 425c of the collet sleeve 42c presses the second inclined surface 415c of the collet 41 in the direction toward the first axis AX. In this way, the diameter of the cylindrical portion 410 of the collet 41 is reduced, and the workpiece W is held by the inner surface 410t of the collet 41.

[0096] In the example shown in FIG. 14, the lathe chuck mechanism 1 (or workpiece holding device 10) includes a biasing member 43. The biasing member 43 biases the sleeve 42 (more specifically, the collet sleeve 42c) in the second direction DR2. The biasing member 43 is, for example, a spring member. In the example shown in FIG. 14, the biasing member 43 is disposed between the collet 41 and the collet sleeve 42c. The biasing member 43 is also disposed inside the collet sleeve 42c.

[0097] In the example shown in FIG. 4, when the piston 3 moves in the first direction DR1, the second portion 33 of the piston 3 (more specifically, the first pressing surface 331 of the piston 3) moves in a direction away from the pressed portion 52a of the toggle 50 (see FIG. 3), and the pressed portion 52a of the toggle 50 moves in a direction away from the first axis AX (see FIG. 3). When the pressed portion 52a of the toggle 50 moves in a direction away from the first axis AX, the toggle 50 swings around the fulcrum 54, and the pressing portion 55 of the toggle 50 moves in the second direction DR2. When the pressing portion 55 of the toggle 50 moves in the second direction DR2, the biasing force of the biasing member 43 moves the sleeve 42 (more specifically, the collet sleeve 42c) and the draw tube 44 in the second direction DR2. In this way, the holding force applied to the workpiece W by the chuck 40 (more specifically, the collet 41) is released (see FIG. 16).

[0098] 14, the draw tube 44 and the sleeve 42 are separate members. Alternatively, the draw tube 44 and the sleeve 42 may be integrated. In other words, the sleeve 42 may be omitted. In this case, the draw tube 44 may be configured to directly press the collet 41 in a direction approaching the first axis AX.

[0099] In the example shown in FIG. 16, the lathe chuck mechanism 1 (or the workpiece holding device 10) has a lock nut 73 that is threaded onto the tip of the spindle 71. The lock nut 73 prevents the chuck 40 from coming off the spindle 71. After the lock nut 73 is removed from the spindle 71, the chuck 40 can be removed from the spindle 71.

[0100] (Rotating body RB) 17, the rotating body RB includes the spindle 71, the toggle 50, the draw tube 44, and the chuck 40 (more specifically, the collet 41). The rotating body RB also includes the second portion 33 of the piston 3. The rotating body RB may include the toggle support 56 and / or the collet sleeve 42c.

[0101] (Support 2) In the example shown in FIG. 17 , the support body 2 includes a housing 20 that accommodates most of the rotating body RB that rotates about the first axis AX. The housing 20 may include a first housing 21 and a second housing 22 that is directly or indirectly connected to the first housing 21. In the example shown in FIG. 17 , the first housing 21 and the second housing 22 are connected to each other by a fixing member BT such as a bolt BT2. In the example shown in FIG. 17 , the housing 20 (more specifically, the first housing 21) accommodates a piston 3. Furthermore, the housing 20 (more specifically, the first housing 21) functions as a cylinder 25 that guides movement of the piston 3 in the direction along the first axis AX. In the example shown in FIG. 17 , the housing 20 (more specifically, the second housing 22) accommodates a plurality of bearings (93, 94) that support a spindle 71 that is disposed outside the draw tube 44. More specifically, the housing 20 (more specifically, the second housing 22) accommodates a front bearing 93 and a rear bearing 94 that support the spindle 71. The housing 20 (more specifically, the second housing 22) may accommodate the rotary drive device 77 (for example, the stator 77a and the rotor 77b of the rotary drive device 77).

[0102] In the example shown in FIG. 17 , the support body 2 (more specifically, the second housing 22) has a front bearing support portion 23 that supports the front bearing 93, and a rear bearing support portion 24 that supports the rear bearing 94. The rear bearing support portion 24 is disposed between the front bearing support portion 23 and the piston 3 in the direction along the first axis AX. The front bearing support portion 23 supports the outer ring of the front bearing 93, and the spindle 71 supports the inner ring of the front bearing 93. The rear bearing support portion 24 supports the outer ring of the rear bearing 94, and the spindle 71 supports the inner ring of the rear bearing 94.

[0103] (Piston 3 drive) In the example shown in FIG. 18, the chuck mechanism 1 of the lathe (or the workpiece holding device 10) has a working fluid supply device 12 that supplies working fluid to the inside of the cylinder 25.

[0104] 18 and 19, the working fluid supply device 12 can supply working fluid (e.g., air, oil, etc.) to a first working fluid receiving space SR1 between the cylinder 25 and the piston 3 (more specifically, a first portion 31 of the piston 3) so that the piston 3 moves from a first position P1 (see FIG. 18) to a second position P2 (see FIG. 19). In the example shown in FIG. 19, the first working fluid receiving space SR1 is sealed by a first elastic ring 61a and another elastic ring (more specifically, a third elastic ring 61c). In the example shown in FIG. 19, the first working fluid receiving space SR1 is an annular space surrounding the outer circumferential surface of the piston 3.

[0105] In the example shown in FIG. 19, the cylinder 25 has a first port 251 that communicates the outside of the cylinder 25 with the first working fluid receiving space SR1. When the working fluid supply device 12 supplies working fluid to the first working fluid receiving space SR1 via the first port 251, the piston 3 moves to the second position P2. In the example shown in FIG. 19, the direction from the first position P1 to the second position P2 is the same as the second direction DR2. In the example shown in FIG. 19, when the piston 3 is in the second position P2, the toggle 50 is in a contracted state (more specifically, a state in which the pressed portion 52a is close to the first axis AX). Furthermore, when the piston 3 is in the second position P2, the workpiece W is held by the chuck 40.

[0106] The working fluid (e.g., air or oil) in the first working fluid receiving space SR1 functions as a vibration suppressing substance that suppresses vibration of the rotating body RB in a direction perpendicular to the first axis AX when the rotating body RB rotates (e.g., when the spindle 71 rotates). In particular, when the rotating body RB rotates, the pressure in the first working fluid receiving space SR1 (e.g., air pressure in the first working fluid receiving space SR1) is made higher than atmospheric pressure, so that the working fluid (e.g., air or oil) in the first working fluid receiving space SR1 effectively functions as a vibration suppressing substance that suppresses vibration of the rotating body RB in a direction perpendicular to the first axis AX. Furthermore, when the first working fluid receiving space SR1 is an annular space that surrounds the outer peripheral surface of the piston 3, the vibration suppression effect of the rotating body RB is enhanced.

[0107] 19, when the piston 3 is located at the second position P2, the piston 3, the toggle 50, and the first working fluid receiving space SR1 are arranged on a plane perpendicular to the first axis AX (more specifically, on a fourth plane PL4 perpendicular to the first axis AX). In this case, the working fluid in the first working fluid receiving space SR1 can suitably support at least a portion of the load acting on the piston 3 in a direction perpendicular to the first axis AX when the rotating body RB rotates (for example, when the spindle 71 rotates). Therefore, vibration of the rotating body RB in the direction perpendicular to the first axis AX is more effectively suppressed when the rotating body RB rotates (for example, when the spindle 71 rotates).

[0108] 18 and 19, the working fluid supply device 12 can supply working fluid (e.g., air, oil, etc.) to a second working fluid receiving space SR2 between the cylinder 25 and the piston 3 (more specifically, the first portion 31 of the piston 3) so that the piston 3 moves from the second position P2 (see FIG. 19) to the first position P1 (see FIG. 18). In the example shown in FIG. 18, the second working fluid receiving space SR2 is sealed by a first elastic ring 61a and a second elastic ring 61b. In the example shown in FIG. 18, the second working fluid receiving space SR2 is an annular space surrounding the outer circumferential surface of the piston 3.

[0109] In the example shown in FIG. 18, the cylinder 25 has a second port 252 that communicates the outside of the cylinder 25 with the second working fluid receiving space SR2. When the working fluid supply device 12 supplies working fluid to the second working fluid receiving space SR2 via the second port 252, the piston 3 moves to the first position P1. In the example shown in FIG. 18, the direction from the second position P2 toward the first position P1 is the same as the first direction DR1. In the example shown in FIG. 18, when the piston 3 is in the first position P1, the toggle 50 is in an expanded state (more specifically, a state in which the pressed portion 52a of the toggle 50 is relatively farther away from the first axis AX than in the contracted state). Furthermore, when the piston 3 is in the first position P1, the chuck 40 releases the workpiece W from being held thereon.

[0110] 18, when the working fluid is supplied to the second working fluid receiving space SR2 by the working fluid supply device 12, the piston 3 moves from the second position P2 to the first position P1. Furthermore, when the piston 3 moves to the first position P1, the working fluid inside the first working fluid receiving space SR1 (see FIG. 19) is discharged from the first working fluid receiving space SR1 to the outside of the cylinder 25.

[0111] 19, when the working fluid is supplied to the first working fluid receiving space SR1 by the working fluid supply device 12, the piston 3 moves from the first position P1 to the second position P2. Furthermore, when the piston 3 moves to the second position P2, the working fluid inside the second working fluid receiving space SR2 (see FIG. 18) is discharged from the second working fluid receiving space SR2 to the outside of the cylinder 25.

[0112] 18 and 19, the working fluid supply device 12 includes an air source 121 and at least one valve 123. The valve 123 is, for example, a solenoid valve 123a.

[0113] In the example shown in FIG. 19, when the state of the valve 123 (e.g., solenoid valve 123a) is the first state, the air source 121 and the first working fluid receiving space SR1 are fluidly connected. In this way, air is supplied from the air source 121 to the first working fluid receiving space SR1. When the state of the valve 123 (e.g., solenoid valve 123a) is the first state, the second working fluid receiving space SR2 (see FIG. 18) and the first air discharge port 126a may be fluidly connected. In the example shown in FIG. 19, the second working fluid receiving space SR2 (see FIG. 18) and the first air discharge port 126a are fluidly connected via the first silencer 125a.

[0114] In the example shown in FIG. 18, when the state of the valve 123 (e.g., solenoid valve 123a) is the second state, the air source 121 and the second working fluid receiving space SR2 are fluidly connected. In this way, air is supplied from the air source 121 to the second working fluid receiving space SR2. When the state of the valve 123 (e.g., solenoid valve 123a) is the second state, the first working fluid receiving space SR1 (see FIG. 19) and the second air discharge port 126b may be fluidly connected. In the example shown in FIG. 18, the first working fluid receiving space SR1 (see FIG. 19) and the second air discharge port 126b are fluidly connected via the second silencer 125b.

[0115] In the examples shown in FIGS. 18 and 19, the chuck mechanism 1 of the lathe (or the workpiece holding device 10) has an air flow path 124 that connects an air source 121 and a cylinder 25. A valve 123 is arranged in the air flow path 124. The air flow path 124 may include a first flow path 124a that connects the valve 123 and a first port 251, and a second flow path 124b that connects the valve 123 and a second port 252. Note that a valve that opens and closes the first flow path 124a and a valve that opens and closes the second flow path 124b may be provided separately.

[0116] The working fluid may be oil. In this case, the working fluid supply device 12 may have a pump that supplies oil, an oil flow path that connects the pump and the cylinder 25, and a valve disposed in the oil flow path. The oil flow path may include a first flow path that supplies oil to the first working fluid receiving space SR1 and a second flow path that supplies oil to the second working fluid receiving space SR2.

[0117] (Third Modification) 20 , the draw tube 44 may be configured to move in a second direction DR2 when the piston 3 moves in a first direction DR1. In the example shown in FIG. 20 , when the piston 3 moves in the first direction DR1, the pressed portion 52a of the toggle 50 is pressed by the second portion 33 of the piston 3 (more specifically, the first pressing surface 331). In addition, in response to the pressed portion 52a being pressed by the second portion 33 of the piston 3, the pressing portion 55 of the toggle 50 presses the draw tube 44 in the second direction DR2. As a result, the draw tube 44 moves in the second direction DR2. The draw tube 44 converts the swinging motion of the toggle 50 into the opening and closing motion of the chuck 40.

[0118] 20, when the draw tube 44 moves in the second direction DR2, the chuck 40 (more specifically, the collet 41) is pressed in a direction approaching the first axis AX. In this way, the workpiece is held by the chuck 40.

[0119] (Second embodiment) A lathe 100 according to the second embodiment will be described with reference to Figures 1 to 23. Figure 21 is a diagram schematically showing the lathe 100 according to the second embodiment. Figures 22 and 23 are block diagrams showing an example of the hardware configuration of a control device 108.

[0120] In the second embodiment, differences from the first embodiment will be mainly described. On the other hand, in the second embodiment, repeated descriptions of matters already described in the first embodiment will be omitted. Therefore, it goes without saying that matters already described in the first embodiment can be applied to the second embodiment even if they are not explicitly described in the second embodiment.

[0121] 21, the lathe 100 in the second embodiment includes a workpiece holding device 10, a machining head 102, and a moving device 105. The lathe 100 in the second embodiment may also include a control device 108.

[0122] The workpiece holding device 10 has already been described in the first embodiment, so a repeated description of the workpiece holding device 10 will be omitted.

[0123] The machining head 102 holds a tool T (more specifically, a turning tool). The moving device 105 moves the machining head 102 relative to the workpiece holding device 10. The machining head 102 may have a tool rotation device that rotates the tool T (more specifically, a milling tool). In other words, the lathe 100 may be capable of selectively performing turning and milling.

[0124] The lathe 100 in the second embodiment has the same effects as the workpiece holding device 10 in the first embodiment.

[0125] (Optional configuration) Next, optional additional configurations that can be employed in the lathe 100 of the second embodiment will be described with reference to FIGS.

[0126] (Mobile device 105) 21 , the movement device 105 includes a machining head movement device 106 that moves the machining head 102. The machining head movement device 106 may include a first drive device 106a that moves the machining head 102 in a direction parallel to the first axis AX, and / or a second drive device 106b that moves the machining head 102 in a direction perpendicular to the first axis AX (e.g., the vertical direction).

[0127] The moving device 105 may include a second moving device 107 that moves the workpiece holding device 10 (more specifically, the support body 2). In the example shown in Fig. 21, the second moving device 107 moves the support body 2 in a direction parallel to the first axis AX.

[0128] (control device 108) The control device 108 controls the rotary drive device 77 and the moving device 105. Additionally, the control device 108 may control the working fluid supply device 12.

[0129] 22, the control device 108 includes a processor 108a, a memory 108b, a communication circuit 108c, an input device 108d, and a display 108e. The processor 108a, the memory 108b, the communication circuit 108c, the input device 108d, and the display 108e are connected to one another via a bus 108f. Data DT required for machining the workpiece W (e.g., shape data of the workpiece W, machining position data of the workpiece W, etc.) may be input to the control device 108 via the input device 108d, or may be input to the control device 108 from another computer via the communication circuit 108c. The input device 108d may be a touch panel on the display 108e. Alternatively, or additionally, the input device 108d may include a button, a switch, a lever, a pointing device, and / or a keyboard.

[0130] The processor 108a generates a control signal by executing the machining program PM stored in the memory 108b. The communication circuit 108c transmits the control signal to the controlled devices (e.g., the rotation drive device 77, the movement device 105, the working fluid supply device 12, etc.). In this way, the processor 108a executes the machining program PM, so that the control device 108 can control the controlled devices (e.g., the rotation drive device 77, the movement device 105, the working fluid supply device 12, etc.).

[0131] 22, the control device 108 transmits a first control signal S1 to the working fluid supply device 12 (more specifically, the valve 123), and the working fluid supply device 12, upon receiving the first control signal S1, supplies the working fluid to the first working fluid receiving space SR1. When the working fluid is supplied to the first working fluid receiving space SR1, the piston 3 moves in a direction along the first axis AX (e.g., the second direction DR2), the toggle 50 pressed by the piston 3 swings, and the draw tube 44 pressed by the toggle 50 moves in a direction along the first axis AX (e.g., the first direction DR1). As the draw tube 44 moves, the chuck 40 (more specifically, the collet 41) is pressed in a direction approaching the first axis AX. In this way, the workpiece W is held by the chuck 40 (more specifically, the collet 41).

[0132] 23, the control device 108 transmits a second control signal S2 to the working fluid supply device 12 (more specifically, the valve 123), and the working fluid supply device 12, upon receiving the second control signal S2, supplies the working fluid to the second working fluid receiving space SR2. When the working fluid is supplied to the second working fluid receiving space SR2, the piston 3 moves in a direction along the first axis AX (for example, in a first direction DR1), the pressing force of the piston 3 is released or alleviated, causing the toggle 50 to swing, the draw tube 44 to move in a direction along the first axis AX (for example, in a second direction DR2), and the chuck 40 (more specifically, the collet 41) to release the workpiece W from its hold.

[0133] The present invention is not limited to the above-described embodiments or modifications, and it is clear that each embodiment or modification can be appropriately modified or changed within the scope of the technical concept of the present invention. Furthermore, various techniques used in each embodiment or modification can be applied to other embodiments or modifications as long as no technical contradiction occurs. Furthermore, optional additional configurations in each embodiment or modification can be omitted as appropriate. [Explanation of symbols]

[0134] 1: Chuck mechanism 2:Support 3: Piston 3a: Annular piston 6: Elastic body 6a: First elastic body 6b: Second elastic body 6c: Third elastic body 10: Work holding device 12: Working fluid supply device 20: Housing 21: 1st Housing 21v: First annular groove 21u: Second annular groove 21w: Third annular groove 22: Second housing 23: Front bearing support 24: Rear bearing support 25: Cylinder 31: First part of piston 31e: End of the first part of the piston on the second direction side 31f: End of the first part of the piston on the first direction side 31v: First annular groove 31u: Second annular groove 31w: Third annular groove 32: Outer ring support part 33: Second part of piston 33c: Cam surface 33e: End of the second portion of the piston on the second direction side 33f: End of the second part of the piston on the first direction side 34: Inner ring support part 35: Bearing 35a: First bearing 35b: Second bearing 36: Outer ring 37: Insider 38: Rolling element 40: Zipper 41: Colette 42: Sleeve 42c: Collet sleeve 43: biasing member 44: Draw tube 44a: Tip of draw tube 44b: Base end of draw tube 44s: Draw tube pressing surface 50: Toggle 50a: First toggle 50b: Second toggle 50c: 3rd toggle 52:Protrusion 52a: Pressed portion 54:Fulcrum 54s: Convex curved surface 55: Pressing part 56: Toggle support 56a: Toggle support sleeve 57: Flange 57s: Concave surface 57v: Groove 58: Sleeve part 58a: End of toggle support 59: Adjustment member 59a: Nut 61: Elastic ring 61a: First elastic ring 61b: Second elastic ring 61c: Third elastic ring 71: Spindle 71a: Tip of spindle 71b: Base end of spindle 73: Lock nut 77: Rotational drive unit 77a: Stator 77b: rotor 93: Front bearing 94: Rear bearing 100: Lathe 102: Processing head 105: Mobile device 106: Processing head moving device 106a: First driving device 106b: Second driving device 107:Second moving device 108: Control device 108a: Processor 108b: Memory 108c: communication circuit 108d: Input device 108e: Display 108f: Bus 121: Air source 123: Valve 123a: Solenoid valve 124: Air flow path 124a: First flow path 124b: Second flow path 125a: 1st silencer 125b: Second silencer 126a: 1st air outlet 126b: 2nd air outlet 251: First port 252: Second port 311: First annular part 312: Second annular part 321: 1st support part 322:Second support part 331: First pressing surface 332: Second pressing surface 341:Third support part 342: 4th support part 410:Cylinder part 410s: Slit 410t: Inner surface 415c: 2nd slope 425c: 1st slope 441: Recess 441s: Pressed surface 511: First arm 512: Second arm 513 :Connection part 615a: Inner surface of first elastic ring 615b: Inner surface of second elastic ring 615c: Inner surface of third elastic ring AT: Central axis of the annular piston AX: 1st axis BT: Fixing member BT1: Bolt BT2: Bolt DR1: 1st direction DR2: 2nd direction DT: Data OP1: 1st opening OP2: Second opening P1: 1st position P2: 2nd position PC1, PC2, PC3, PC4, PC5, PC6, PC7, PC8: Plane PL1: 1st plane PL2: 2nd plane PL3: 3rd plane PL4: 4th plane PM: Machining program RB: Rotating body S1: First control signal S2: Second control signal SP1: Internal space defined by the inner surface of the piston SP2: The internal space defined by the inner surface of the first part of the piston SQ1: Internal space defined by the inner surface of the first elastic ring SQ2: Internal space defined by the inner surface of the second elastic ring SQ3: Internal space defined by the inner surface of the third elastic ring SR1: First working fluid receiving space SR2: Second working fluid receiving space T:Tool W: Work

Claims

1. A cylinder; a piston disposed inside the cylinder; a chuck that holds the workpiece by opening and closing and is rotatable around a first axis; a toggle disposed inside the piston, rotatable around the first axis, and swinging in accordance with the movement of the piston; a draw tube that is rotatable about the first axis and movable along the first axis, and that converts the pivoting motion of the toggle into the opening and closing motion of the chuck; an elastic body disposed between the cylinder and the piston; Equipped with Lathe chuck mechanism.

2. The piston and the toggle are disposed on a first plane perpendicular to the first axis.

2. The lathe chuck mechanism according to claim 1.

3. The elastic body, the piston, and the toggle are arranged on a first plane perpendicular to the first axis.

2. The lathe chuck mechanism according to claim 1.

4. The elastic body is a first elastic ring; a second elastic ring; a third elastic ring; Including, the first elastic ring is disposed between the second elastic ring and the third elastic ring in a direction along the first axis, The first elastic ring is disposed on the first plane.

4. The chuck mechanism for a lathe according to claim 3.

5. a hydraulic fluid supply device that supplies hydraulic fluid to a first hydraulic fluid receiving space between the cylinder and the piston so that the piston moves from the first position to the second position; 2. The lathe chuck mechanism according to claim 1.

6. The piston is an annular piston.

6. The chuck mechanism for a lathe according to claim 1.

7. The piston is a first portion that contacts the elastic body; a second portion that contacts the toggle; a bearing disposed between the first portion and the second portion; have 6. The chuck mechanism for a lathe according to claim 1.

8. The toggle a pressed portion that is pressed by the piston; a fulcrum of the swinging motion; a pressing portion that presses the draw tube in a direction substantially parallel to the first axis; have 6. The chuck mechanism for a lathe according to claim 1.

9. The chuck is a collet sleeve pressed by the draw tube; a collet pressed by the collet sleeve; Contains 6. The chuck mechanism for a lathe according to claim 1.

10. The elastic body suppresses vibration of the piston and the toggle in a direction perpendicular to the first axis when a rotating body including the toggle rotates.

6. The chuck mechanism for a lathe according to claim 1.

11. a chuck that holds the workpiece by opening and closing and is rotatable around a first axis; a rotating body including the chuck; a support body including a cylinder and supporting the rotating body so that the rotating body is rotatable about the first axis; a piston disposed inside the cylinder; an elastic body disposed between the cylinder and the piston; a rotation drive device that rotates the rotating body around the first axis; Equipped with The rotating body is The chuck; a toggle disposed inside the piston and swinging in accordance with the movement of the piston; a draw tube movable along the first axis and converting the pivoting motion of the toggle into the opening and closing motion of the chuck; Contains Work holding device.

12. a first housing that accommodates the piston and guides the movement of the piston; a second housing connected to the first housing and containing a plurality of bearings supporting a spindle disposed outside the draw tube; Equipped with The workpiece holding device according to claim 11.

13. A work holding device; a machining head for holding a tool; a moving device that moves the processing head relative to the workpiece holding device; Equipped with The workpiece holding device is a chuck that holds the workpiece by opening and closing and is rotatable around a first axis; a rotating body including the chuck; a support body including a cylinder and supporting the rotating body so that the rotating body is rotatable about the first axis; a piston disposed inside the cylinder; an elastic body disposed between the cylinder and the piston; a rotation drive device that rotates the rotating body around the first axis; Equipped with The rotating body is The chuck; a toggle disposed inside the piston and swinging in accordance with the movement of the piston; a draw tube movable along the first axis and converting the pivoting motion of the toggle into the opening and closing motion of the chuck; Contains lathe.

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