Guide lining device and adjusting method of guide lining device

Abstract

The invention provides a guide lining device which is easy to adjust and an adjusting method of the guide lining device. This guide bush device (6) supports a rod-shaped workpiece (W) so as to be capable of sliding in the direction of the axis (AL) of the workpiece (W), and is provided with: a guide bush (62); a guide bush (63) which is disposed inside the guide bush sleeve (62), has a bush thread (63d) formed thereon, and has an inner diameter that varies in accordance with a position relative to the guide bush sleeve (62) in the direction of the axis (AL); a pull-in sleeve (64) that is disposed inside the guide bush sleeve (62) and on which a first thread (64a) that meshes with the bush thread (63d) and a second thread (64b) that differs from the first thread (64a) in pitch are formed; and a differential attachment / detachment body (65) in which a differential thread (65a) that meshes with the second thread (64b) is formed, the differential attachment / detachment body (65) being able to be fixed to and unfixed from the guide bush sleeve (62).

Description

Technical Field

[0001] The present invention relates to a guide bushing device for freely slidably supporting a rod-shaped workpiece along the axial direction of the workpiece and an adjustment method for the guide bushing device. Background Art

[0002] There is known a guide bushing device that includes a guide bushing that freely slidably supports the front end portion of a rod-shaped workpiece held by a main shaft along the axial direction of the workpiece (for example, refer to Patent Document 1). In a machine tool equipped with a guide bushing device, during machining, the workpiece is supported at two positions, the main shaft and the guide bushing device, to suppress the deflection of the workpiece. Therefore, it is possible to machine particularly long and slender workpieces with high precision. The guide bushing device described in Patent Document 1 includes: a guide bushing having an outer peripheral inclined surface on the outer peripheral surface of the front end side; a guide bushing sleeve that houses the guide bushing inside and has an inner peripheral inclined surface on the inner peripheral surface of the front end side; and a pull-in sleeve (pull rod). By using the pull-in sleeve to displace the relative position of the guide bushing and the guide bushing sleeve in the axial direction of the workpiece, it is possible to change the pressing force between the outer peripheral inclined surface and the inner peripheral inclined surface and adjust the inner diameter of the guide bushing. Further, by adjusting the inner diameter of the guide bushing, an appropriate gap can be formed between the guide bushing and the workpiece. This gap is preferably extremely small, but if it is too small, the guide bushing firmly holds the workpiece, which increases the sliding resistance when moving the workpiece in the axial direction. Therefore, fine adjustment is required.

[0003] In the guide bushing device described in Patent Document 1, a male thread is formed on the outer periphery of the rear end side of the guide bushing, and a female thread having a pitch smaller than the male thread of the guide bushing is formed on the inner peripheral surface of the rear end side of the guide bushing sleeve. Further, a female thread that meshes with the male thread of the guide bushing is formed on the outer periphery of the front end side of the pull-in sleeve, and a male thread that meshes with the female thread of the guide bushing sleeve is formed on the outer periphery of the rear end side of the pull-in sleeve to form a differential mechanism. By using the differential mechanism, even if the pull-in sleeve is rotated one turn, the displacement amount of the relative position of the guide bushing and the guide bushing sleeve in the axial direction is only the pitch difference between the female thread of the pull-in sleeve and the male thread of the pull-in sleeve. Therefore, the inner diameter of the guide bushing can be finely adjusted.

[0004] [Background Art Documents]

[0005] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent No. 6711527 Gazette Summary of the Invention

[0007] [Problems to be Solved by the Invention]

[0008] However, in the guide bushing device described in Patent Document 1, although fine adjustment can be achieved, on the other hand, when the pull-in sleeve is rotated one turn, the change amount of the inner diameter of the guide bushing is small, and it is necessary to rotate the pull-in sleeve multiple turns to adjust the guide bushing to the desired inner diameter. Therefore, there is a problem of complicated adjustment.

[0009] In addition, in the guiding bush device described in Patent Document 1, at the point in time when the female thread of the pulling sleeve meshes with the male thread of the guiding bush, the number of meshing threads of the male thread of the pulling sleeve and the female thread of the guiding bush sleeve changes according to the position of the guiding bush at that point in time. Therefore, the relative position in the axial direction between the adjusted guiding bush sleeve and the pulling sleeve changes significantly with the number of meshing threads. As a result, when the guiding bush is adjusted to a desired inner diameter, there are sometimes cases where the pulling sleeve protrudes significantly rearward from the guiding bush sleeve. In such a case, the pulling sleeve may come into contact with the main shaft or the tool. Also, depending on the number of meshing threads, it is considered that even if the pulling sleeve is screwed into the deep part of the hole formed in the guiding bush sleeve, it may not be possible to bring the outer peripheral inclined surface of the guiding bush into a crimped state with the inner peripheral inclined surface of the guiding bush sleeve. In the case where these states occur, it is necessary to disengage the female thread of the pulling sleeve from the male thread of the guiding bush and readjust, so there is also a problem that the adjustment work becomes more cumbersome.

[0010] The present invention has been completed in view of the above problems, and an object thereof is to provide an easily adjustable guiding bush device and an adjustment method for the guiding bush device.

[0011] [Technical means for solving the problem]

[0012] The guiding bush device of the present invention for solving the above problems is characterized in that:

[0013] It supports the rod-shaped workpiece slidably in the axial direction of the workpiece, and includes:

[0014] A guiding bush sleeve;

[0015] A guiding bush, disposed inside the guiding bush sleeve, having a bush thread formed thereon, and an inner diameter that changes according to the relative position in the axial direction with respect to the guiding bush sleeve;

[0016] A pulling sleeve, disposed inside the guiding bush sleeve, having a first thread that meshes with the bush thread and a second thread having a pitch different from that of the first thread; and

[0017] A differential attachment / detachment body, having a differential thread that meshes with the second thread, and capable of being fixed to the guiding bush sleeve and released from the guiding bush sleeve.

[0018] According to this guide bush device, by rotating the pulling sleeve while the differential handling body is not fixed to the guide bush sleeve, the guide bush can be relatively moved greatly in the axial direction with respect to the guide bush sleeve. In addition, by rotating the pulling sleeve while the differential handling body is fixed to the guide bush sleeve, the guide bush can be relatively moved slightly in the axial direction with respect to the guide bush sleeve, so that the adjustment of the guide bush becomes easy.

[0019] Here, the guide bush device can freely rotate with the axis of the workpiece as the rotation axis. When the differential handling body is not fixed to the guide bush sleeve, the pulling sleeve moves the guide bush only by the pitch of the first thread in the axial direction with respect to the guide bush sleeve for each rotation of the pulling sleeve. When the differential handling body is fixed to the guide bush sleeve and the second thread can rotate relative to the differential thread, the pulling sleeve moves the guide bush only by the difference between the pitch of the first thread and the pitch of the second thread in the axial direction with respect to the guide bush sleeve for each rotation of the pulling sleeve. The differential handling body can also be fixed to the guide bush sleeve by a fastening member. The guide bush may also have an outer peripheral inclined surface whose diameter increases toward the front end side on its outer peripheral surface. In addition, the guide bush sleeve may also have an inner peripheral inclined surface whose diameter increases toward the front end side on its inner peripheral surface. The bush thread, the first thread, the second thread, and the differential thread may also have an axial direction in the axial direction.

[0020] This guide bush device may also be in the following form:

[0021] It includes a switching member that changes between a non-rotatable state in which the pulling sleeve and the differential handling body cannot rotate relative to each other and a rotatable state in which the pulling sleeve and the differential handling body can rotate relative to each other.

[0022] According to this form, the state can be simply changed to the non-rotatable state and the rotatable state.

[0023] Here, the pulling sleeve may be formed with a groove that divides the second thread, and the switching member may change the state to the non-rotatable state and the rotatable state by changing the width of the groove to change the pressing force between the second thread and the differential thread. The groove may be locally formed in the circumferential direction along the circumferential direction of the second thread. In addition, the switching member may increase the pressing force between the second thread and the differential thread by increasing the width of the groove to form the non-rotatable state.

[0024] In this guide bush device,

[0025] The pitch of the first thread may also be greater than that of the second thread.

[0026] Thus, by rotating the pulling sleeve while the differential mounting body is not fixed to the guide bushing sleeve, the guide bushing can be relatively moved greatly in the axial direction with respect to the guide bushing sleeve, so that the adjustment of the guide bushing becomes easier.

[0027] The guide bushing device may also be as follows:

[0028] It includes a pressing member that sandwiches the differential mounting body between the guide bushing sleeve by tightening the fastening member, thereby fixing the differential mounting body to the guide bushing sleeve.

[0029] The differential mounting body releases the fixation by the pressing member by weakening the tightening of the fastening member, and thus rotates freely with respect to the guide bushing sleeve.

[0030] By weakening the tightening of the fastening member and rotating the pulling sleeve together with the differential mounting body, the engagement between the bushing thread and the first thread can be released, and the guide bushing can be removed from the guide bushing sleeve. In addition, the bushing thread can be engaged with the first thread, so that the guide bushing can be loaded and unloaded without disassembling the fastening member. Thus, there is no need to worry about the dropping of the fastening member during the replacement operation of the guide bushing.

[0031] In addition, in the adjustment method of the guide bushing device of the present invention for solving the above problems,

[0032] The guide bushing device slidably supports the workpiece freely in the axial direction of the rod-shaped workpiece, and includes: a guide bushing sleeve; a guide bushing whose inner diameter changes according to the relative position with the guide bushing sleeve in the axial direction; a pulling sleeve formed with a first thread that engages with a bushing thread formed on the guide bushing and a second thread having a pitch different from that of the first thread; and a differential mounting body formed with a differential thread that engages with the second thread. The adjustment method of the guide bushing device is characterized by including:

[0033] A rough adjustment step of rotating the pulling sleeve in a non-rotatable state that cannot rotate relative to the differential mounting body with respect to the guide bushing, thereby relatively moving the guide bushing in the axial direction with respect to the guide bushing sleeve;

[0034] A switching step of fixing the differential mounting body that has ended the rough adjustment step to the guide bushing sleeve to form a rotatable state in which the pulling sleeve and the differential mounting body can rotate relative to each other; and

[0035] A fine adjustment step rotates the pull-in sleeve that ends the switching step relative to the guide bushing and the differential handling body, thereby relatively moving the guide bushing in the axial direction relative to the guide bushing sleeve.

[0036] According to this guide bushing adjustment method, in the rough adjustment step, the guide bushing can be relatively moved greatly, and in the fine adjustment step, the guide bushing can be relatively moved slightly. Therefore, the adjustment of the guide bushing becomes easy.

[0037] Here, a rotation prohibition step may also be included. The rotation prohibition step is performed before the rough adjustment step to form a non-rotatable state in which the pull-in sleeve and the differential handling body cannot rotate relative to each other. In addition, a final switching step may also be included. The final switching step makes the pull-in sleeve that ends the fine adjustment step and the differential handling body in the non-rotatable state. In addition, in the rough adjustment step, the guide bushing can be moved in the axial direction relative to the guide bushing sleeve by engaging the bushing thread with the first thread. In addition, in the fine adjustment step, the guide bushing can also be moved in the axial direction relative to the guide bushing sleeve by engaging the bushing thread with the first thread and engaging the second thread with the differential thread.

[0038] [Advantages of the Invention]

[0039] According to the present invention, a guide bushing device that is easy to adjust and an adjustment method for the guide bushing device can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a top view simply showing the internal structure of the NC (Numerical Control) lathe of the present embodiment.

[0041] Figure 2 is a cross-section taken along a vertical plane passing through the axis Figure 1 The shown guide bushing device is a sectional perspective view observed from slightly above and obliquely behind.

[0042] Figure 3 is a cross-section taken along a vertical plane passing through the axis Figure 2 The cross-sectional view of the shown guide bushing device.

[0043] Figure 4 In (a) of Figure 2 The exploded perspective view of the shown guide bushing device, and (b) is a cross-section taken along a vertical plane passing through the axis Figure 2 The exploded cross-sectional view of the shown guide bushing device.

[0044] Figure 5 is observed from slightly obliquely above and in front of Figure 2A perspective view of the situation where the anti-rotation auxiliary tool of the guide bushing device is installed.

[0045] Figure 6 It is a flowchart showing the steps of installing a guide bushing, a pulling sleeve, and a differential attachment / detachment body on a guide bushing sleeve, and the step of adjusting the inner diameter of the guide bushing.

[0046] Figure 7 In (a) of Figure 2 It is a cross-sectional view showing the situation where the pulling unit shown is inserted into the guide bushing sleeve, and (b) is a cross-sectional view showing the situation where the fastening screw is screwed into the guide bushing device after rough adjustment.

[0047] Figure 8 In (a) to (d) of

[0048] Figure 9 It is a flowchart showing the steps of detaching the pulling unit and the guide bushing from the guide bushing sleeve.

[0049] Figure 10 It is a cross-sectional perspective view of the guide bushing device of the second embodiment cut by a vertical plane passing through the axis and viewed from slightly above and obliquely behind, which is the same as Figure 2 the cross-sectional view.

[0050] Figure 11 In (a) of Figure 10 It is an exploded perspective view of the guide bushing device shown, and (b) is an exploded cross-sectional view of the guide bushing device shown cut by a vertical plane passing through the axis. Figure 10 the cross-sectional view.

[0051] Figure 12 It is a cross-sectional view showing the situation of replacing the guide bushing in the guide bushing device shown in Figure 10 the cross-sectional view. Detailed implementation mode

[0052] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In this embodiment, an example of applying the present invention to a guide bushing device provided in a Swiss-type NC (Numerical Control) lathe will be used for description.

[0053] Figure 1 It is a top view simply showing the internal structure of the NC lathe 1 of this embodiment.

[0054] As Figure 1As shown, a control device 2, a main shaft 3, a main shaft table 4, a tool post 5, and a guide bush device 6 are provided on an NC lathe 1. The control device 2 is a computer that operates the main shaft 3, the main shaft table 4, the tool post 5, and the guide bush device 6 according to an NC program. In addition to the operations using the NC program, the NC lathe 1 can also be operated by directly inputting commands to the control device 2 from an operation unit (not shown). A partition wall 11 is fixed to the base, i.e., the foot portion, of the NC lathe 1. The interior of the NC lathe 1 is divided by the partition wall 11 into a main shaft table chamber 12 and a machining chamber 13. Hereinafter, the side of the main shaft table chamber 12 is referred to as the rear, and the side of the machining chamber 13 is referred to as the front. In Figure 1 the figure, the right side in the figure is the front, and the left side in the figure is the rear.

[0055] According to a signal from the control device 2, the main shaft 3 changes between a holding state and a holding release state. The holding state is a state in which a long bar-shaped workpiece W inserted therein is held, and the holding release state is a state in which the holding of the workpiece W is released. The main shaft 3 is mounted on the main shaft table 4 and rotates freely. It rotates by receiving a signal from the control device 2 through a main shaft motor (not shown), and the main shaft 3 and the workpiece W held by the main shaft 3 rotate about the axis AL of the workpiece W. That is, the axis AL of the workpiece W is also the rotation center line of the main shaft 3.

[0056] According to a signal from the control device 2, the main shaft table 4 moves along the Z1 axis together with the main shaft 3. The Z1 axis is a horizontal direction, and in Figure 1 the figure, it is the left-right direction. This Z1 axis is in the same direction as the axis AL of the workpiece W.

[0057] The tool post 5 is mounted on the partition wall 11 and can move along the X1 axis orthogonal to the Z1 axis and facing the horizontal direction, and the Y1 axis facing the vertical direction. The tool post 5 receives a signal from the control device 2 and moves along the X1 axis and the Y1 axis. Figure 1 In the figure, the up-down direction is the X1 axis, and the direction orthogonal to the paper surface is the Y1 axis. A machining tool T for machining the workpiece W is mounted on the tool post 5. Figure 1 The figure shows a case where the machining tool T is mounted on the tool post 5. On the tool post 5, a variety of machining tools T are arranged and mounted along the Y1 axis, including a turning tool for outer diameter machining, a turning tool for cutting, etc. By moving the tool post 5 along the Y1 axis, any one of these various machining tools T is selected. Then, by moving the tool post 5 along the X1 axis, the selected machining tool T is inserted into the workpiece W held by the main shaft 3 to machine the workpiece W.

[0058] The guide bushing device 6 slidably supports the front end portion of the workpiece W in the axial direction of the axis AL of the workpiece W. The workpiece W is held by the main spindle 3, and the front end side protrudes forward from the main spindle 3. The guide bushing device 6 includes a rotating portion that rotates about the axis AL of the workpiece in synchronization with the main spindle 3 by receiving a signal from the control device 2 by a guide bushing motor (not shown). That is, the axis AL of the workpiece is also the rotation center line of the guide bushing device 6. The presence of the guide bushing device 6 suppresses the deflection of the workpiece W during machining, so that a particularly long and slender workpiece W can be machined with high precision.

[0059] Figure 2 is a cross-section taken along a vertical plane passing through the axis AL Figure 1 The sectional perspective view of the guide bushing device 6 shown, as viewed obliquely from slightly above the rear. In addition, Figure 3 is a cross-section taken along a vertical plane passing through the axis AL Figure 2 The cross-sectional view of the guide bushing device 6 shown. In addition, Figure 2 In, the hatching indicating the cross-section is not marked. In addition, Figure 3 In, the partition wall 11 and the following timing belt 623 are shown by solid lines, and only the outer periphery of the workpiece W is shown by a double-dot chain line.

[0060] As Figure 2 shown, the guide bushing device 6 includes a guide bushing body 61, a guide bushing sleeve 62, a guide bushing 63, a pulling-in sleeve 64, a differential mounting body 65, and a bearing 66. Among them, the guide bushing sleeve 62, the guide bushing 63, the pulling-in sleeve 64, and the differential mounting body 65 are rotating portions that rotate about the axis AL. The guide bushing body 61 is a block in which a space for accommodating the guide bushing sleeve 62 is formed inside, and the rear portion is cylindrical. In addition, the guide bushing sleeve 62, the guide bushing 63, and the pulling-in sleeve 64 are substantially cylindrical, and the differential mounting body 65 is substantially annular.

[0061] As Figure 3 shown, the cylindrical portion at the rear of the guide bushing body 61 is inserted into the guide bushing mounting hole 11a formed in the partition wall 11 and fixed to the partition wall 11 by screws (not shown). The front portion of the guide bushing body 61 protrudes into the main spindle chamber 12 (see Figure 1 ).

[0062] The guide bushing sleeve 62 is supported on the guide bushing body 61 by three bearings 66, and is freely rotatable with the axis AL as the rotation center and cannot move in the direction of the axis AL. The guide bushing sleeve 62 has a sleeve body 620, a pulley 621 and a nut 622. At the front end portion of the sleeve body 620, an inner circumferential inclined surface 620a whose diameter increases as it moves forward is formed. The pulley 621 and the nut 622 are firmly mounted on the sleeve body 620, and the sleeve body 620, the pulley 621 and the nut 622 are substantially integrated. A timing belt 623 that transmits the driving force of the guide bushing motor is wound around the pulley 621. By driving the guide bushing motor, the guide bushing sleeve 62 rotates with the axis AL direction as the rotation center. In addition, the guide bushing motor, the pulley 621 and the timing belt 623 can be omitted. When they are omitted, the guide bushing sleeve 62 rotates in conjunction with the guide bushing 63, the pull-in sleeve 64, and the differential loading and unloading body 65 following the rotation of the workpiece W. Alternatively, the guide bushing sleeve 62 may be fixed to the guide bushing body 61 so that it cannot rotate. When the guide bushing sleeve 62 is fixed, when the workpiece W rotates, the guide bushing 63 slides in the rotation direction together with the workpiece W. The inner nut 622 is roughly annular, and inner nut screw holes 622a that penetrate in the front-rear direction are formed at multiple locations in the circumferential direction.

[0063] The guide bushing 63 is arranged at the inner front part of the guide bushing sleeve 62. The center line of the guide bushing 63 is consistent with the axis AL. A sliding surface 63a that slides with the workpiece W is formed on the inner periphery of the front side of the guide bushing 63. In addition, an outer peripheral inclined surface 63b whose diameter increases toward the front is formed on the outer peripheral surface of the front side of the guide bushing 63. By moving the guide bushing 63 backward in a state where the outer peripheral inclined surface 63b is in contact with the inner peripheral inclined surface 620a of the guide bushing sleeve 62, the sliding surface 63a located at the front side part of the guide bushing 63 is reduced in diameter in the radial direction against the elasticity of the guide bushing 63 itself. In other words, the inner diameter of the guide bushing 63 changes according to the relative position of the guide bushing sleeve 62 and the guide bushing 63 in the direction of the axis AL. A part of the outer peripheral surface of the guide bushing 63 is formed to have a diameter slightly smaller than the inner peripheral surface of the front part of the guide bushing sleeve 62 except the inner peripheral inclined surface 620a. A portion of the outer peripheral surface thereof serves as a guide when the guide bush 63 is inserted into the guide bush sleeve 62 .

[0064] On the outer peripheral surface on the rear side of the guide bush 63, a key groove 63c and a bush thread 63d extending in the direction of the axis AL are formed. The lower end of the anti-rotation pin 631 inserted into the pin hole formed in the guide bush sleeve 62 enters the key groove 63c. The guide bush 63 uses the anti-rotation pin 631 and the key groove 63c to prevent relative rotation with the guide bush sleeve 62. Therefore, the guide bush sleeve 62 and the guide bush 63 rotate integrally with the axis AL as the rotation center. On the other hand, the movement of the guide bush 63 in the direction of the axis AL is not restricted by the anti-rotation pin 631. The bush thread 63d is a male thread with an axial pitch in the direction of the axis AL, and the pitch is 1.0. In addition, the guide bush 63 is a commercially available general part prepared according to the inner diameter of each sliding surface 63a. Regardless of the inner diameter of the sliding surface 63a, the pitch is basically set to 1.0. The unit of this pitch is mm, the same below.

[0065] The pulling sleeve 64 is arranged in the inner rear part of the guide bush sleeve 62. The center line of the pulling sleeve 64 coincides with the axis AL. On the inner peripheral surface on the front side of the pulling sleeve 64, a first thread 64a meshing with the bush thread 63d is formed. Figure 2 and Figure 3 The meshing of the bush thread 63d and the first thread 64a is shown. The first thread 64a is a female thread with an axial pitch in the direction of the axis AL, and the pitch is the same as that of the bush thread 63d. In the following rough adjustment and fine adjustment, although the degree of change is different, in the adjustment step, the relative position of the guide bush 63 and the pulling sleeve 64 is changed by changing the number of meshing threads of the bush thread 63d and the first thread 64a.

[0066] A second thread 64b is formed on the outer peripheral surface on the rear side of the pulling sleeve 64. The second thread 64b is a male thread with an axial pitch in the direction of the axis AL, and the pitch is 0.8. In addition, the pitch of the second thread 64b can be the same as or different from that of the first thread 64a. It is preferably that the difference in pitch from the first thread 64a does not reach the pitch of the first thread 64a (1.0 in this embodiment). In addition, a groove 64c that divides the second thread 64b in the direction of the axis AL is formed in the rear side part of the pulling sleeve 64. The groove 64c is formed in two parts locally in the circumferential direction along the circumferential direction of the pulling sleeve 64. At the rear end face of the pulling sleeve 64 and at the position corresponding to the center part in the circumferential direction of the groove 64c, two screw holes recessed in the direction of the axis AL are formed. Plug pins 641 with a length less than the depth of the screw holes are inserted into the bottom side (front side) of these screw holes. In addition, headless full-thread screws 642 are screwed in on the edge side (rear side) of the screw holes closer to the plug pins 641. A part of the outer peripheral surface of the pulling sleeve 64 is formed to have a diameter slightly smaller than the inner peripheral surface of the rear part of the guide bush sleeve 62. A part of its outer peripheral surface serves as a guide when inserting the pulling sleeve 64 into the guide bush sleeve 62.

[0067] As Figure 2As shown, on the rear end face of the pulling-in sleeve 64, a plurality of tool insertion holes 64d recessed in the axial direction are formed. When the pulling-in sleeve 64 is rotatable relative to the differential mounting body 65 or when the differential mounting body 65 is not fixed to the guide bush sleeve 62, a protrusion of a tool is inserted into the tool insertion hole 64d and the tool is rotated, whereby the pulling-in sleeve 64 can be rotated about the axis AL as the rotation center.

[0068] As described above, the differential mounting body 65 is substantially annular, and a differential thread 65a engaged with the second thread 64b is formed on its inner peripheral surface. Figure 2 and Figure 3 The engagement of the second thread 64b and the differential thread 65a is shown. The differential thread 65a is a female thread having an axial direction along the axis AL, and the pitch is the same as that of the second thread 64b. When the second thread 64b and the differential thread 65a are engaged and the front end of the headless full-thread screw 642 is in contact with the rear end of the plug pin 641, when the headless full-thread screw 642 is further screwed in, the width of the groove 64c increases. As a result, the second thread 64b on the front side of the groove 64c and the second thread 64b on the rear side of the groove 64c are separated, and the pressing force between the second thread 64b and the differential thread 65a increases, so that a non-rotatable state in which the pulling-in sleeve 64 and the differential mounting body 65 cannot rotate relative to each other is achieved. On the contrary, by rotating the headless full-thread screw 642 in the loosening direction, the second thread 64b on the front side of the groove 64c and the second thread 64b on the rear side of the groove 64c return to their original intervals, so that a rotatable state in which the pulling-in sleeve 64 and the differential mounting body 65 can rotate relative to each other is achieved. That is, the headless full-thread screw 642 functions as a switching member that changes the pulling-in sleeve 64 and the differential mounting body 65 between a non-rotatable state and a rotatable state. Figure 2 and Figure 3 The non-rotatable state is shown. In addition, the differential mounting body 65 functions as a frontward movement prevention means. In the non-rotatable state, the front end of the differential mounting body 65 is in contact with the rear end of the guide bush sleeve 62 (inner nylon nut 622), thereby preventing the pulling-in sleeve 64 from moving forward.

[0069] As Figure 3As shown, the differential attachment body 65 is formed with a plurality of stepped holes 65b that penetrate in the front-rear direction. The stepped holes 65b are holes with a larger diameter at the rear and a smaller diameter at the front, and are formed at the same angular intervals as the nylon screw holes 622a. When fixing the differential attachment body 65 to the guide bushing sleeve 62, the stepped holes 65b are aligned with the nylon screw holes 622a, and the fastening screw 651 is inserted into the stepped holes 65b. Then, by screwing the fastening screw 651 into the nylon screw hole 622a, the screw head of the fastening screw 651 presses against the stepped portion of the stepped hole 65b, and the differential attachment body 65 is fixed to the guide bushing sleeve 62. Conversely, by removing the fastening screw 651, the fixing of the differential attachment body 65 to the guide bushing sleeve 62 is released. The fastening screw 651 corresponds to an example of a fastening member.

[0070] Figure 4 (a) in Figure 2 is an exploded perspective view of the guide bushing device 6 shown in Figure 4 (b) in Figure 2 is an exploded cross-sectional view of the guide bushing device 6 shown in Figure 4 In (a) in Figure 4 the illustration of the threads of the second thread 64b and the differential thread 65a is omitted. Additionally, Figure 4 in (a) in

[0071] As Figure 4 shown in (a) in Figure 4 and (b) in

[0072] Figure 5 is a perspective view of observing the situation where the anti-rotation auxiliary tool 9 is installed on the guide bushing device 6 shown in Figure 2 from a slightly obliquely front-upper position.

[0073] As Figure 5As shown, the anti-rotation auxiliary tool 9 that prevents the rotation of the guide bushing sleeve 62 can be attached to and detached from the guide bushing body 61. The anti-rotation auxiliary tool 9 is a plate-shaped auxiliary tool in a substantially Y shape. The anti-rotation auxiliary tool 9 is attached to the guide bushing body 61 when replacing the guide bushing 63 and when adjusting the inner diameter of the guide bushing 63.

[0074] Hereinafter, with reference to Figure 7 and Figure 8 and using Figure 6 , the steps of attaching the guide bushing 63, the pulling sleeve 64, and the differential attachment / detachment body 65 to the guide bushing sleeve 62, and the steps of adjusting the inner diameter of the guide bushing 63 will be described.

[0075] Figure 6 FIG. is a flowchart showing the steps of attaching the guide bushing 63, the pulling sleeve 64, and the differential attachment / detachment body 65 to the guide bushing sleeve 62, and the steps of adjusting the inner diameter of the guide bushing 63.

[0076] As Figure 6 shown, the operator of the NC lathe 1 first inserts the guide bushing 63 into the guide bushing sleeve 62 supported by the guide bushing body 61 and freely rotatable from the front (step S11). Then, the Figure 5 shown anti-rotation auxiliary tool 9 is attached to the guide bushing body 61 to lock the guide bushing sleeve 62 so that it does not rotate (step S12). Next, the operator meshes the differential thread 65a of the differential attachment / detachment body 65 with the second thread 64b of the pulling sleeve 64, relatively rotates the pulling sleeve 64 and the differential attachment / detachment body 65 until the rear end face of the pulling sleeve 64 is substantially aligned with the rear end face of the differential attachment / detachment body 65, and screws in the headless full thread screw 642 to make the pulling sleeve 64 and the differential attachment / detachment body 65 in a non-rotatable state (step S13). Hereinafter, the pulling sleeve 64 and the differential attachment / detachment body 65 that have become in a non-rotatable state may sometimes be referred to as the pulling unit. In addition, this step S13 can also be implemented before step S11 or step S12.

[0077] Figure 7 In (a) of FIG., it is a cross-sectional view showing the case where the pulling unit in which the pulling sleeve 64 and the differential attachment / detachment body 65 are integrated is inserted into the guide bushing sleeve 62. In addition, Figure 7 in (a) of FIG., the illustration of the anti-rotation auxiliary tool 9 is omitted.

[0078] After the steps up to step S13 are completed, as Figure 7As shown by the hollow arrow in (a) thereof, the operator inserts the pulling-in unit from the rear of the guide bush sleeve 62. Then, by rotating the pulling-in unit (pulling-in sleeve 64) positively relative to the guide bush 63, the first thread 64a of the pulling-in sleeve 64 is engaged with the bush thread 63d of the guide bush 63. When the front end face of the differential handling body 65 contacts the rear end face of the guide bush sleeve 62 and the pulling-in unit is further rotated positively, the guide bush 63 is pulled backward, and the outer peripheral inclined surface 63b is pressed by the inner peripheral inclined surface 620a of the guide bush sleeve 62, so that the guide bush 63 is reduced in diameter in the radial direction. Here, the operator inserts the workpiece W into the guide bush 63, and while confirming the sliding force of the workpiece W in the Z1 axial direction and the guiding function of the guide bush 63, rotates the pulling-in unit positively. If the sliding force is too strong, the pulling-in unit is rotated reversely, thereby performing a rough adjustment of the guide bush 63 (the above is step S14). This step S14 corresponds to an example of the rough adjustment step. In addition, the positive rotation means the clockwise rotation of the pulling-in sleeve 64 when viewed from the rear to the front of the guide bush device 6, and the reverse rotation means the counterclockwise rotation of the pulling-in sleeve 64 when viewed in the same direction. As described above, the guide bush 63 relatively moves backward and is reduced in diameter relative to the guide bush sleeve 62 by this positive rotation, and relatively moves forward and is increased in diameter relative to the guide bush sleeve 62 by the reverse rotation.

[0079] Figure 7 (b) in it is a cross-sectional view showing the case where the fastening screw 651 is screwed into the guide bush device 6 after the rough adjustment is completed. In addition, Figure 7 The illustration of the anti-rotation auxiliary tool 9 is omitted in (b) in it.

[0080] After the rough adjustment performed by step S14 is completed, as Figure 7 shown by the hollow arrow in (b) in it, the operator fixes the differential handling body 65 to the guide bush sleeve 62 by inserting the fastening screw 651 into the stepped hole 65b and screwing in the fastening screw 651 (step S15).

[0081] Figure 8 is a cross-sectional view of the guide bush device 6 for explaining the switching step of the rotation state and the fine adjustment step. This Figure 8 shows the main part on the upper side of the guide bush device 6. In addition, Figure 8 the illustration of the anti-rotation auxiliary tool 9 is omitted in it.

[0082] As Figure 8 shown in (a) in it, in the state after step S15 is completed, the pulling-in unit is fixed to the guide bush sleeve 62. As Figure 8As shown in (b) thereof, the operator loosens the headless full-thread screw 642 from this state, making the pulling-in sleeve 64 and the differential handling body 65 rotatable (step S16). These steps S15 and S16 are an example of the switching steps. Through steps S15 and S16, with the differential handling body 65 fixed to the guide bushing sleeve 62, the pulling-in sleeve 64 becomes capable of rotating about the axis AL as the rotation center. In addition, step S16 can also be executed first and then step S15.

[0083] After step S16 ends, as Figure 8 shown in (c) thereof, when the pulling-in sleeve 64 is rotated forward, through the forward rotation of the second thread 64b meshing with the differential thread 65a, for each full rotation, the pulling-in sleeve 6 moves forward by 0.8 mm of the pitch. On the other hand, through the forward rotation of the first thread 64a meshing with the bushing thread 63d, for each full rotation, the pulling-in sleeve 64 and the guide bushing 63 move toward each other by 1 mm of the pitch. Through these, every time the pulling-in sleeve 64 rotates forward one full turn, the guide bushing 63 is pulled backward relative to the guide bushing sleeve 62 and reduced in diameter by 0.2 mm, which is the difference in their pitches. Conversely, when the pulling-in sleeve 64 is rotated backward, for each full rotation, the guide bushing 63 is pushed forward relative to the guide bushing sleeve 62 and increased in diameter by 0.2 mm. Here, the operator makes the pulling-in sleeve 64 rotate forward and backward relative to the guide bushing 63 and the differential handling body 65 while confirming the sliding force of the workpiece W inserted into the guide bushing 63 in the Z1 axial direction and the guiding function of the guide bushing 63, thereby finely adjusting the inner diameter of the guide bushing 63 (the above is step S17). This step S17 is an example of the fine adjustment step.

[0084] After the fine adjustment ends, as Figure 8 shown in (d) thereof, the operator screws in the headless full-thread screw 642, making the pulling-in sleeve 64 and the differential handling body 65 non-rotatable (step S18). This step S18 is an example of the final switching step. Thereby, the guide bushing 63, the pulling-in sleeve 64, and the differential handling body 65 are fixed to the guide bushing sleeve 62. Finally, the operator removes the anti-rotation auxiliary tool 9 from the guide bushing body 61, making the guide bushing sleeve 62 freely rotatable (step S19). Above, the installation of the guide bushing 63, the pulling-in sleeve 64, and the differential handling body 65 to the guide bushing sleeve 62 and the adjustment of the guide bushing 63 are completed.

[0085] Next, the steps for disassembling the pulling-in unit and the guide bush 63 from the guide bush sleeve 62 will be described. In addition, when machining a workpiece W with an outer diameter different from that of the previously machined workpiece W, as one of the so-called preparation operations, the guide bush 63 is replaced according to the outer diameter of the workpiece W to be machined next. In this replacement operation, the steps for disassembling the pulling-in unit and the guide bush 63 from the guide bush sleeve 62 described below are performed, and then, the inner diameter adjustment of the new guide bush 63 and the fixing of the guide bush 63 and the like to the guide bush sleeve 62 are performed through steps S11 to S19 other than step S13.

[0086] Figure 9 FIG. is a flowchart showing the steps for disassembling the pulling-in unit and the guide bush 63 from the guide bush sleeve 62.

[0087] As Figure 9 shown, the operator first installs the anti-rotation auxiliary tool 9 on the guide bush body 61 and locks the guide bush sleeve 62 so that it does not rotate (step S21). Next, the fastening screw 651 is disassembled to release the fixing of the guide bush sleeve 62 and the pulling-in unit (differential attachment / detachment body 65) (step S22). Thereafter, the operator reversely rotates the pulling-in unit (pulling-in sleeve 64) to release the engagement of the bush thread 63d of the guide bush 63 and the first thread 64a of the pulling-in sleeve 64, and withdraws the pulling-in unit from the guide bush sleeve 62 (step S23).

[0088] Then, the operator disassembles the anti-rotation auxiliary tool 9 from the guide bush body 61 (step S24). Finally, the guide bush 63 is withdrawn from the guide bush sleeve 62 (step S25). The above is the end of the operation of disassembling the pulling-in unit and the guide bush 63 from the guide bush sleeve 62.

[0089] According to the guide bush device 6 of the present embodiment described above, by rotating the pulling-in sleeve 64 in a state where the differential attachment / detachment body 65 is not fixed to the guide bush sleeve 62, the guide bush 63 can be relatively moved greatly in the axial direction AL with respect to the guide bush sleeve 62, so that the guide bush 63 can be quickly and roughly adjusted. Then, in a state where the differential attachment / detachment body 65 is fixed to the guide bush sleeve 62, the engagement of the bush thread 63d and the first thread 64a and the engagement of the differential thread 65a and the second thread 64b function as a differential mechanism, and even if the pulling-in sleeve 64 is rotated one turn, the guide bush 63 only slightly displaces with respect to the guide bush sleeve 62. Therefore, the inner diameter of the guide bush 63 can be finely adjusted. Through these, the inner diameter adjustment of the guide bush 63 becomes easy.

[0090] In addition, the rough adjustment is completed by performing a rough adjustment in a state where the differential loading and unloading body 65 is not fixed to the guide bushing sleeve 62. Therefore, in the fine adjustment, it is only necessary to slightly rotate the pull-in sleeve 64, suppressing a large displacement of the position of the pull-in sleeve 64 in the axial direction of the axis AL due to the fine adjustment. Thus, it is possible to prevent the pull-in sleeve 64 from protruding significantly rearward from the differential loading and unloading body 65, thereby reducing the limitation of the movement range of the main shaft 3 in the Z1 axial direction. In addition, it is also possible to suppress the contact between the tool used for maintenance work and the protruding portion of the pull-in sleeve 64, which may interfere with the maintenance work.

[0091] In addition, by screwing in the headless full-thread screw 642, the pull-in sleeve 64 and the differential loading and unloading body 65 can be changed between a non-rotatable state and a rotatable state, so that the rotatable state can be simply changed.

[0092] Furthermore, the pitch of the first thread 64a is made larger than the pitch of the second thread 64b. Therefore, in the rough adjustment performed in a state where the differential loading and unloading body 65 is fixed to the guide bushing sleeve 62, the displacement amount of the guide 63 in the axial direction of the axis AL can be made larger with one rotation of the pull-in sleeve 64. Conversely, the pitch of the second thread 64b can be made larger than the pitch of the first thread 64a. However, if it is too large, in the rough adjustment, the inner diameter of the guide 63 is reduced by positive rotation, and in the fine adjustment, the same positive rotation enlarges the inner diameter of the guide 63, so that the operator may be confused. In the present embodiment, the pitch of the first thread 64a is made larger than the pitch of the second thread 64b, and it is configured that in both the rough adjustment and the fine adjustment, the inner diameter of the guide 63 is reduced by positive rotation and enlarged by reverse rotation, so that the operator can be prevented from being confused. In addition, depending on the direction of rotation of the pull-in sleeve 64 in the fine adjustment, if the pitch of the second thread 64b is larger, the amount of protrusion of the pull-in sleeve 64 from the differential loading and unloading body 65 may increase compared to the case where the pitch is smaller. In the present embodiment, by making the pitch of the second thread 64b smaller than the pitch of the first thread 64a, even if the pull-in sleeve 64 protrudes rearward from the differential loading and unloading body 65 in the fine adjustment, the amount of protrusion can be made smaller. Thus, the possibility of re-adjustment required to reduce the rearward protrusion amount of the pull-in sleeve 64 can be reduced. Through these, the adjustment of the inner diameter of the guide 63 becomes easier.

[0093] Next, the guide device 6 of the second embodiment will be described. In the following description, sometimes the same reference numerals as those used above are assigned to the same components as those described above, and the repeated description is omitted.

[0094] Figure 10 That is, the guide device 6 of the second embodiment is cut by a vertical plane passing through the axis AL and viewed from slightly above obliquely behind with Figure 2Identical sectional perspective views. Additionally, Figure 11 In (a) of Figure 10 is an exploded perspective view of the guide bushing device 6 shown in Figure 11 In (b) of Figure 10 is an exploded sectional view of the guide bushing device 6 shown in Figure 10 In, hatching indicating the cross-section is not marked. Additionally, Figure 11 In (a) of

[0095] As Figure 10 and Figure 11 shown, the difference between the guide bushing device 6 of the second embodiment and the above-described embodiment lies in the shape of the differential attachment / detachment body 65 and the provision of the pressing member 67. The differential attachment / detachment body 65 is in the shape of a flanged cylinder, in which the cylindrical portion 65c formed at the rear and the flange portion 65d formed at the front and protruding outward in diameter from the cylindrical portion 65c are integrated.

[0096] The pressing member 67 is substantially annular. The inner peripheral surface of the pressing member 67 includes a rear inner peripheral surface 67a and a front inner peripheral surface 67b having a diameter larger than that of the rear inner peripheral surface 67a. The diameter of the rear inner peripheral surface 67a is slightly larger than that of the cylindrical portion 65c of the differential attachment / detachment body 65 and smaller than that of the flange portion 65d. The diameter of the front inner peripheral surface 67b is larger than that of the flange portion 65d. Additionally, a plurality of pressing portion stepped holes 67c penetrating in the front-rear direction are formed in the pressing member 67. The pressing portion stepped hole 67c is a hole having a larger diameter at the rear and a smaller diameter at the front, and is formed at the same angular interval as the inner nylon screw hole 622a. Additionally, Figure 11 In (a) of Figure 4 is shown a case where the fastening screw 651 is inserted into the pressing portion stepped hole 67c of the pressing member 67, and in order to facilitate the observation of the pressing member 67 and the fastening screw 651,

[0097] In the guide bushing device 6 of this second embodiment, by screwing in the fastening screw 651, the differential attachment / detachment body 65 is sandwiched between the pressing member 67 and the guide bushing sleeve 62 (inner nylon nut 622), thereby fixing the differential attachment / detachment body 65 to the guide bushing sleeve 62. Figure 10The case where the differential handling body 65 is fixed to the guide bush sleeve 62 is shown. Further, by loosening the fastening screw 651, the fixing of the differential handling body 65 with respect to the guide bush sleeve 62 is released by weakening the fastening of the fastening screw 651, and it is freely rotatable. In addition, when detaching the differential handling body 65 and the pressing member 67 from the guide bush sleeve 62, it is necessary to detach the fastening screw 651 from the guide bush sleeve 62. Conversely, in the state where only the fastening screw 651 is loosened and the threaded portion of the fastening screw 651 still engages with the nylon screw hole 622a, the differential handling body 65 is freely rotatable with respect to the guide bush sleeve 62 but remains mounted on the guide bush sleeve 62. In addition, in this state, the pressing member 67 also remains mounted on the guide bush sleeve 62.

[0098] In the guide bush device 6 of the second embodiment, the steps of mounting the guide bush 63, the pulling-in sleeve 64, and the differential handling body 65 on the guide bush sleeve 62, and the step of adjusting the inner diameter of the guide bush 63 can also be implemented by the same steps as in the above-described embodiment. However, in step S15, the differential handling body 65 is not directly fixed to the guide bush sleeve 62 with the fastening screw 651, but the differential handling body 65 is fixed by sandwiching the differential handling body 65 between the pressing member 67 and the guide bush sleeve 62 with the fastening screw 651. In addition, the steps of detaching the pulling-in unit and the guide bush 63 from the guide bush sleeve 62 can also be implemented by the same steps as in the above-described embodiment. However, in the second embodiment, the difference from the above-described embodiment is that when replacing the guide bush 63, it is not necessary to detach the pulling-in unit from the guide bush sleeve 62, and the guide bush 63 can be replaced by loading and unloading the guide bush 63 with respect to the guide bush sleeve 62.

[0099] Figure 12 It shows in Figure 10 a cross-sectional view showing the case of replacing the guide bush 63 in the shown guide bush device 6.

[0100] When taking out the guide bush 63 when replacing the guide bush 63, the operator first locks the rotation of the guide bush sleeve 62 using the rotation prevention jig 9 (refer to Figure 5 ). In addition, Figure 12 the illustration of the rotation prevention jig 9 is omitted in Figure 12 . Then, as shown in Figure 12 , by loosening the fastening screw 651, the fixing of the differential handling body 65 with respect to the guide bush sleeve 62 is released, and by reversely rotating the pulling-in unit, as shown by the two-dot chain line in Figure 12 , the guide bush 63 is pushed forward. Then, by reversely rotating the pulling-in sleeve 64 and the differential handling body 65 together, the engagement between the bush thread 63d and the first thread 64a is released, and thus the guide bush 63 can be withdrawn from the guide bush sleeve 62.

[0101] Next, after pulling out the previously installed guide bushing 63 from the guide bushing sleeve 62, a new guide bushing 63' is installed in the guide bushing sleeve 62. The outer peripheral shapes of the guide bushing 63 and the new guide bushing 63' are the same, and only the inner diameter of the sliding surface 63a part is different. When installing the new guide bushing 63', as shown by the thick black arrow in Figure 12 , the new guide bushing 63' is inserted into the guide bushing sleeve 62, and the pulling-in unit is rotated forward, whereby the bushing thread 63d is engaged with the first thread 64a. Then, the guide bushing 63 is pulled backward by rotating the pulling-in unit forward, and the rough adjustment of the guide bushing 63 is performed in the same manner as in step S14. Thereafter, the operation of installing the new guide bushing 63' in the guide bushing sleeve 62 is completed by performing the processes after steps S15 to S19. In addition, in this process, in step S15, the differential mounting body 65 is clamped between the pressing member 67 and the guide bushing sleeve 62 by the fastening screw 651, whereby the differential mounting body 65 is fixed to the guide bushing sleeve 62.

[0102] The guide bushing device 6 of the second embodiment also produces the same effects as the above-described embodiment. In addition, even without disassembling the fastening screw 651, the differential mounting body 65, and the pressing member 67 from the guide bushing sleeve 62 by rotating the pulling-in sleeve 64 by weakening the fastening of the fastening screw 651, the guide bushing 63 can be attached to and detached from the guide bushing sleeve 62. Therefore, there is also an effect that there is no need to worry about the dropping of the fastening screw 651 and the differential mounting body 65 during the replacement operation of the guide bushing 63.

[0103] The present invention is not limited to the above-described embodiments, and various changes can be made within the scope described in the claims. For example, in the description of the present embodiment, the guide bushing device 6 provided in the NC lathe 1 is illustrated, and the guide bushing device 6 of the present invention can also be applied to machine tools other than the NC lathe 1. In addition, the NC lathe 1 may be provided with a rear spindle, a rear spindle table, and a rear spindle tool post facing the main spindle 3. Furthermore, the bushing thread 63d of the guide bushing 63 may be a female thread, and the first thread 64a of the pulling-in sleeve 64 may be a male thread. In addition, furthermore, the second thread 64b of the pulling-in sleeve 64 may be a female thread, and the differential thread 65a of the differential mounting body 65 may be a male thread. Also, steps S13 and S16 may be omitted, and instead, the following step may be provided after step S14: the differential thread 65a of the differential mounting body 65 is engaged with the second thread 64b of the pulling-in sleeve 64, and the differential mounting body 65 is rotated clockwise when viewed from the rear to the front of the guide bushing device 6 until the front end face of the differential mounting body 65 contacts the rear end face of the guide bushing sleeve 62. However, in this case, since the rough adjustment of step S14 is performed visually, it is preferably to install the guide bushing 63 by performing the steps of S11 to S19.

[0104] In addition, even the constituent elements included only in the descriptions of the respective embodiments or respective modification examples described above can be applied to other embodiments or other modification examples.

[0105] [Reference Signs]

[0106] 1: NC lathe

[0107] 6: Guide bushing device

[0108] 62: Guide bushing sleeve

[0109] 63: Guide bushing

[0110] 63d: Bushing thread

[0111] 64: Pull-in sleeve

[0112] 64a: First thread

[0113] 64b: Second thread

[0114] 65: Differential loading and unloading body

[0115] 65a: Differential thread

[0116] W: Workpiece.

Claims

1. A guide bushing device, characterized in that: The rod-shaped workpiece is supported so as to be freely slidable along the axial direction of the workpiece, and comprises: Guide bushing; A guide bushing is arranged inside the guide bushing sleeve, is formed with bushing threads, and has an inner diameter that varies according to a relative position with the guide bushing sleeve in the axial direction; A pull-in sleeve is disposed inside the guide bushing and is formed with a first thread that meshes with the bushing thread and a second thread having a different pitch from the first thread; and The differential attachment and detachable body has a differential thread that meshes with the second thread, and can be fixed to and released from the guide bushing.

2. The guide bushing device according to claim 1 comprises a switching component which switches between a non-rotatable state in which the pulling-in sleeve and the differential attachment and detachable body cannot rotate relative to each other and a rotatable state in which the pulling-in sleeve and the differential attachment and detachable body can rotate relative to each other. 3 . The guide bushing device according to claim 1 , wherein a pitch of the first thread is greater than a pitch of the second thread.

4. The guide bushing device according to any one of claims 1 to 3, comprising a pressing member which sandwiches the differential detachable body between the guide bushing sleeve by fastening with a fastening member, thereby fixing the differential detachable body to the guide bushing sleeve. The differential detachable body releases the fixation by the pressing member by weakening the fastening of the fastening member, thereby freely rotating relative to the guide bushing.

5. A method for adjusting a guide bushing device, the guide bushing device supporting a rod-shaped workpiece in a freely slidable manner along the axial direction of the workpiece, and comprising a guide bushing sleeve; a guide bushing whose inner diameter changes according to the relative position with the guide bushing sleeve in the axial direction; a sleeve drawn in, formed with a first thread meshing with a bushing thread formed on the guide bushing, and a second thread having a pitch different from the first thread; and a differential attachment and detachment body, formed with a differential thread meshing with the second thread; the method for adjusting the guide bushing device is characterized by comprising: A general adjustment step of rotating the retracting sleeve in a non-rotatable state relative to the differential attachment and detachable body relative to the guide bushing, thereby causing the guide bushing to move relative to the guide bushing sleeve in the axial direction; a switching step of fixing the differential attachment and detachable body after the rough adjustment step to the guide bushing, and switching the state to a rotatable state in which the retracting sleeve and the differential attachment and detachable body can rotate relative to each other; and The fine adjustment step is to rotate the retracting sleeve that has completed the switching step relative to the guide bush and the differential attachment and detachable body, thereby causing the guide bush to move relative to the guide bush sleeve in the axial direction.

Images