JP7464816B2 - Lathe and method for attaching guide member thereto - Google Patents

Description

The present invention relates to a lathe that can switch between a machining method that uses a guide bush and a machining method that does not use a guide bush, and a method for attaching a guide member thereto.

As shown in Patent Document 1, a known lathe is a moving-spindle type lathe in which a guide bush that slidably supports a workpiece is attached to a support table in front of the spindle. In the case of a guide bush type that uses a guide bush, the workpiece held by the spindle is slidably supported by the guide bush and machined by a cutting tool in front of the guide bush. On the other hand, in order to machine a short workpiece, the guide bush may be removed from the support table and the headstock may be advanced compared to when the guide bush is used to machine the workpiece. In the case of a non-guide bush type that does not use a guide bush, an annular quill guide attached to the support table is used to slidably support the front part of the headstock in the direction of the spindle center line. The quill guide is attached to the support table, and a quill arranged outside the spindle with the spindle centered on the spindle center line is inserted in the front part of the headstock.

When switching from the guide bush system to the non-guide bush system, the lathe operator removes the guide bush from the support table, first positions the quill guide on the outside of the quill, moves the headstock forward, and then attaches the quill guide to the support table with a screw. At this point, since changing the mounting position of the quill guide affects the machining accuracy of the workpiece, the operator aligns the center line of the quill guide with the center line of the spindle. Therefore, the operator performs work that involves center alignment every time he switches from the guide bush system to the non-guide bush system.

JP 2016-144843 A

The quill guide is annular and heavy, larger than the quill, to support the quill so that it can slide. Therefore, the installation work of the quill guide, which involves centering the quill guide by pushing up the quill guide that is located on the outside of the quill and attaching it to the support base, places a heavy burden on the operator.

The present invention discloses a lathe that can reduce the work required to switch from a guide bush type to a non-guide bush type, and a method for attaching the guide members.

The lathe of the present invention comprises a spindle for gripping a workpiece;
a headstock having a quill arranged on the outside of the spindle with the center line of the spindle as the center, and rotatably supporting the spindle;
a drive unit that moves the headstock in a direction along the center line of the headstock;
a support base on which a guide bush that slidably supports the workpiece is removably provided in front of the spindle;
a guide member attached to the support base from which the guide bush has been removed, and supporting the quill slidably in the direction of the center line of the spindle;
a positioning member attached to the support base and adapted to align a center line of the guide member with a center line of the spindle ;
In a cross section perpendicular to the center line of the spindle, the positioning member attached to the support base and the guide member attached to the support base are in contact at two contact points that form a triangle with the center of the guide member.

The method for attaching a guide member to a lathe according to the present invention further comprises the steps of:
A spindle that grips the workpiece;
a headstock having a quill arranged on the outside of the spindle with the center line of the spindle as the center, and rotatably supporting the spindle;
a drive unit that moves the headstock in a direction along the center line of the headstock;
A support base on which a guide bush that slidably supports the workpiece is removably provided in front of the spindle;
a guide member that is attached to the support base from which the guide bush has been removed, and that supports the quill slidably in a direction toward a center line of the spindle, comprising:
a positioning step of contacting the guide member with a positioning member attached to the support base, the positioning member being configured to align a center line of the guide member with a center line of the spindle;
and a mounting step of mounting the guide member abutted against the positioning member to the support base from which the guide bush has been removed,
In a cross section perpendicular to the center line of the spindle, the positioning member attached to the support base and the guide member attached to the support base are in contact at two contact points that form a triangle with the center of the guide member.

The present invention provides a lathe that reduces the work involved in switching from a guide bush type to a non-guide bush type.

FIG. 2 is a schematic cross-sectional view of a main part of a lathe. 2A and 2B are schematic diagrams illustrating, in partial cross section, the main parts of a guide bush type lathe. 3A and 3B are perspective views each showing a schematic simplified example of a main part of a lathe. 4A and 4B are schematic diagrams illustrating, in partial cross section, the main parts of a lathe using a non-guide bush system. FIG. 2 is a perspective view showing a schematic simplified example of a main part of a lathe using a non-guide bush system. 5A to 5C are diagrams illustrating an example of a positional relationship between a positioning member and a guide member in a cross section perpendicular to the center line of the spindle. Figure 7A is a cross-sectional view illustrating, in a schematic manner, how a guide member is attached when a positioning member is not attached to the support base of the guide bush; Figure 7B is a cross-sectional view illustrating, in a schematic manner, how a positioning member is attached to the support base by contacting the guide member; and Figure 7C is a cross-sectional view illustrating, in a schematic manner, how the positioning member is fixed to the support base. 8A is a cross-sectional view that illustrates a schematic example of a state in which the guide bush has been removed from the support base, and FIG. 8B is a cross-sectional view that illustrates a schematic example of a state in which the guide member is attached to the support base by abutting against the positioning member. 9A to 9C are schematic diagrams showing modified examples of the positioning member together with the guide member in a cross section perpendicular to the center line of the spindle. 13A and 13B are diagrams illustrating modified examples of the positioning member and the guide member in a cross section perpendicular to the center line of the spindle. FIG. 11A is a cross-sectional view showing a schematic view of a guide member being attached to a support base of a guide bush in a comparative example, and FIG. 11B is a cross-sectional view showing a schematic view of a guide member in a comparative example in which the center line of the guide member is deviated from the center line of the spindle.

The following describes embodiments of the present invention. Of course, the following embodiments are merely examples of the present invention, and not all of the features shown in the embodiments are necessarily essential to the solution of the invention.

(1) Overview of the technology included in the present invention:
First, the outline of the technology included in the present invention will be described with reference to the examples shown in the drawings. Note that the drawings in this application are diagrams showing examples in a schematic manner, and the magnification ratios in each direction shown in these drawings may differ, and each drawing may not be consistent. Of course, each element of the present technology is not limited to the specific example shown by the symbol.
In addition, in this application, a numerical range "Min to Max" means a value equal to or greater than the minimum value Min and equal to or less than the maximum value Max.

[Aspect 1]
As illustrated in Figs. 1 and 5, the lathe 1 according to one aspect of the present technology includes a spindle 12 that grips a workpiece W1, a headstock 10, a drive unit 20, a support base 30, a guide member 40, and a positioning member 50. The headstock 10 has a quill 11 arranged on the outside of the spindle 12 with the spindle center line AX1 as the center, and rotatably supports the spindle 12. The drive unit 20 moves the headstock 10 in the spindle center line direction D1. A guide bush 32 that slidably supports the workpiece W1 in front of the spindle 12 is detachably provided on the support base 30. The guide member 40 is attached to the support base 30 from which the guide bush 32 has been removed, and supports the quill 11 slidably in the spindle center line direction D1. The positioning member 50 is attached to the support base 30, and aligns the center line AX2 of the guide member 40 with the spindle center line AX1.

11A and 11B are cross-sectional views showing a schematic diagram of a process of switching from a guide bush type to a non-guide bush type in a comparative example lathe having no positioning member. Fig. 11A shows a state where an annular guide member 940 is attached to a support base 930 from which the guide bush has been removed.
The quill 911 provided on the headstock 910 is a substantially cylindrical member supported by the guide member 940, and is disposed on the outside of the headstock 912 with the spindle center line AX91 as its center, and extends from a main body 910a of the headstock 910 to a front side S91. The headstock 910 having the quill 911 moves in the Z-axis direction along the spindle center line AX91 during machining of a workpiece. Therefore, the guide member 940 needs to support the quill 911 so that it can slide in the Z-axis direction, and a slight gap is provided between an inner peripheral surface 941 of the guide member 940 and an outer peripheral surface 911a of the quill 911.

When attaching the guide member 940 to the support table 930, the lathe operator performs the following centering operations.
First, in order to align the center line AX92 of the guide member 940 with the spindle center line AX91, the operator first places the guide member 940 outside the quill 911, and places the quill 911 in the through hole 940a of the guide member 940. Next, the operator advances the headstock 910, and places a part of the quill 911 in the through hole 931 of the support base 930. Furthermore, the operator holds the guide member 940 while supporting the guide member 940 with his/her hand so that the center line AX92 of the guide member 940 is aligned with the spindle center line AX91. While maintaining this state, the operator inserts the screw SC91 into the screw insertion hole 943 of the guide member 940 and screws it into the screw hole 933 of the support base 930, and the guide member 940 is fixed to the support base 930. The operator needs to perform the above-mentioned work every time he/she switches from the guide bush type to the non-guide bush type.

Here, when the guide member 940 is screwed in a state in which the center line AX92 of the guide member 940 is shifted from the spindle center line AX91 as shown in FIG. 11A, as shown in FIG. 11B, a deviation occurs in the gap between the inner peripheral surface 941 of the fixed guide member 940 and the outer peripheral surface 911a of the quill 911. In FIG. 11A and 11B, as a result of the center line AX92 of the guide member 940 being shifted downward from the spindle center line AX91, a relatively wide gap CL9 is generated between the inner peripheral surface 941 of the guide member 940 and the outer peripheral surface 911a of the quill 911 below the quill 911. When the center line AX92 of the guide member 940 is shifted from the spindle center line AX91, it affects the machining accuracy of the workpiece. However, since the guide member 940 supports the quill 911 in a slidable manner, it has a ring shape larger than the quill and is heavy. Therefore, the task of attaching the guide member 940 to the support table 930 while aligning the guide member 940 places a heavy burden on the operator. In addition, because the same task must be performed every time the guide bush system is switched from the guide bush system to the non-guide bush system, the attachment position of the guide member 940 changes slightly each time, and differences in the attachment position can affect the machining accuracy of the workpiece.

Meanwhile, in the above-mentioned aspect 1 of the present technology, when the operator of the lathe 1 attaches the guide member 40 to the support table 30 from which the guide bush 32 has been removed, the operator can use the positioning member 50 to align the center line AX2 of the guide member 40 with the spindle center line AX1. This eliminates the need to perform a burdensome task of centering, such as pushing up the heavy guide member 40, every time, and also eliminates the need to first position the guide member 40 outside the quill 11 every time. Therefore, the above-mentioned aspect 1 can provide a lathe that reduces the work of switching from the guide bush type to the non-guide bush type.

Here, the number of positioning members may be one or two or more. This statement also applies to the following aspects:

[Aspect 2]
6, in a cross section CS perpendicular to the spindle center line AX1, the positioning member 50 attached to the support base 30 and the guide member 40 attached to the support base 30 may be in contact with each other at two contact points P1 and P2 that form a triangle TR with a center P3 of the guide member 40. As a result, when an operator presses the guide member 40 against the positioning member 50, the guide member 40 and the positioning member 50 come into contact with each other at the two contact points P1 and P2, and the center line AX2 of the guide member 40 coincides with the spindle center line AX1. Therefore, in this embodiment, the center line of the guide member can be accurately positioned to the spindle center line.
Here, the guide member and the positioning member may be in contact at two contact points in a cross section perpendicular to the spindle center line, and may be in linear contact overall. Contact at a contact point in a cross section means point contact in design, and includes linear contact due to errors in the shapes of the guide member and the positioning member, etc. These remarks are also applied to the following aspects.

[Aspect 3]
6, 9A, 9B, etc., the surface (e.g., contact surface 51) of the positioning member 50 where the contact points P1, P2 exist may be a flat surface or a concave curved surface having a radius of curvature larger than the radius of curvature of the outer circumferential surface 42 of the guide member 40 in the cross section CS. This aspect makes it possible to easily realize the two contact points P1, P2 between the positioning member 50 and the guide member 40, and therefore makes it possible to easily position the center line of the guide member with the spindle center line.

[Aspect 4]
As illustrated in FIGS. 7A and 8B, the guide member 40 may have a front/back discrimination unit (e.g., a counterbore 43a) capable of discriminating whether the guide member 40 is in an upside-down state relative to the support base 30. When the guide member 40 is attached in an upside-down state relative to the support base 30, the position of the central axis AX2 of the guide member 40 in the upside-down state may be slightly shifted from the position of the central axis AX2 of the guide member 40 in the unupside-down state. In order to match the position of the central axis AX2 in the upside-down state and the unupside-down state, the guide member 40 needs to be machined with extremely high precision. In this embodiment, since the front/back discrimination unit (43a) can determine whether the guide member 40 is in an upside-down state relative to the support base 30, the operator can attach the guide member 40 in an unupside-down state to the support base 30. In this case, the machining of the guide member 40 does not require high precision to match the position of the central axis AX2 in the upside-down state and the unupside-down state. Therefore, this embodiment can reduce the cost of the guide member.
Here, the front/back discriminating portion is not limited to a countersink, but may be a mark or the like for identifying the front/back of the guide member.

[Aspect 5]
Meanwhile, a method for attaching a guide member to a lathe 1 according to one aspect of the present technology includes the following steps (a) and (b).
(a) A positioning step ST1 in which the guide member 40 is brought into contact with a positioning member 50 attached to the support base 30, the positioning member 50 aligning the center line AX2 of the guide member 40 with the main shaft center line AX1.
(b) An attachment step ST2 in which the guide member 40 abutting against the positioning member 50 is attached to the support base 30 from which the guide bush 32 has been removed.

In the above aspect 5, the operator of the lathe 1 can align the center line AX2 of the guide member 40 with the spindle center line AX1 by placing the guide member 40 against the positioning member 50 attached to the support base 30 from which the guide bush 32 has been removed. In this state, the operator can attach the guide member 40 to the support base 30. This eliminates the need to perform a burdensome task of centering, such as pushing up the heavy guide member 40, every time, and also eliminates the need to first position the guide member 40 outside the quill 11 every time. Therefore, the above aspect 5 can provide a method for attaching a guide member to a lathe that reduces the work of switching from a guide bush type to a non-guide bush type.

(2) Example of a lathe:
FIG. 1 is a schematic diagram of a main part of a lathe 1 using a guide bush system, partially in cross section. FIG. 2A is a schematic diagram of a main part of a lathe 1 using a guide bush system, partially in cross section from above. FIG. 2B is a schematic diagram of a main part of a lathe 1 using a guide bush system, partially in cross section from the Y-axis direction. FIG. 3A is a schematic diagram of a main part of a lathe 1 using a guide bush system, partially in cross section. FIG. 3B is a schematic diagram of a main part of a lathe 1 using a non-guide bush system, partially in cross section. FIG. 4A is a schematic diagram of a main part of a lathe 1 using a non-guide bush system, partially in cross section from above. FIG. 4B is a schematic diagram of a main part of a lathe 1 using a non-guide bush system, partially in cross section from the Y-axis direction. In FIGS. 2A, 2B, 4A, and 4B, the front end position of the headstock 10 is indicated by a solid line, and the rear end position of the headstock 10 is indicated by a two-dot chain line.
The spindle center line AX1 indicates the center line of rotation of the spindle 12, and the spindle center line direction D1 indicates the direction along the spindle center line AX1. The spindle center line direction D1 includes both the direction toward the front side S1 and the direction toward the rear side S2. The Z-axis direction indicates the direction of the control axis along the spindle center line direction D1, the X-axis direction indicates the direction of the control axis along the vertical direction perpendicular to the Z-axis direction, and the Y-axis direction indicates the direction of the control axis along the horizontal direction perpendicular to the Z-axis direction. The X-axis direction, the Y-axis direction, and the Z-axis direction may be different from each other, and although it is preferable that they are substantially perpendicular to each other from the viewpoint of ease of movement control, they may be directions that are shifted from the perpendicular direction by an angle of, for example, 45° or less.

The lathe 1 shown in FIG. 1 is a moving-spindle lathe equipped with a base 2, a control unit 8, a headstock 10, a drive unit 20, a support table 30, a tool rest 60, etc. The base 2 is also called a bed or table, etc., and constitutes the base portion that supports the drive unit 20, the support table 30, etc.

The control unit 8 controls the operation of the headstock 10, the drive unit 20, the tool rest 60, etc. A known numerical control device can be used for the control unit 8. The numerical control device includes a processor (Central Processing Unit) CPU, a semiconductor memory (Read Only Memory) ROM, a semiconductor memory (Random Access Memory) RAM, a timer circuit, an interface, etc. A control program for interpreting and executing a machining program is written in the ROM. Machining programs created by an operator are rewritably stored in the RAM. The CPU uses the RAM as a work area and executes the control program recorded in the ROM to realize the functions of the numerical control device. Of course, some or all of the above functions may be realized by other means such as an ASIC (Application Specific Integrated Circuit).

The spindle 12 provided on the headstock 10 releasably grips the cylindrical (rod-shaped) workpiece W1 inserted in the Z-axis direction and rotates the workpiece W1 around the spindle center line AX1 along the longitudinal direction of the workpiece W1. The headstock 10 supports the spindle 12 rotatably around the spindle center line AX1 and is movable in the Z-axis direction. A cylindrical quill 11 is provided at the front of the headstock 10 to support the spindle 12 rotatably around the spindle center line AX1. The quill 11 provided on the headstock 10 is a substantially cylindrical member supported by the guide member 40 when the guide bush 32 is not used, and is disposed outside the spindle 12 around the spindle center line AX1 and extends from the main body 10a of the headstock 10 to the front side S1. As shown in Figures 3A and 3B, the outer circumferential surface 11a of the quill 11 has a circular cross section. The headstock 10, which has a quill 11, moves in the Z-axis direction when machining the workpiece.

The drive unit 20 has a motor 21 supported by the base 2 and a feed mechanism 22 along the spindle center line AX1, and moves the headstock 10 in the Z-axis direction. The motor 21 is a servo motor that can be numerically controlled by the control unit 8. The feed mechanism 22 shown in FIG. 1 is a ball screw in which a screw shaft 23 and a nut 24 operate via balls. The screw shaft 23 is arranged along the spindle center line AX1, and its rear end is connected to the motor 21 via a coupling. Therefore, the screw shaft 23 is rotated by the motor 21 around a rotation axis along the spindle center line AX1. The nut 24 is screwed onto the screw shaft 23 via balls, fixed to the headstock 10, and moves in the Z-axis direction in response to the rotation of the screw shaft 23.

The support table 30 supported by the base 2 has a through hole 31 for mounting the guide bush 32. The guide bush 32 attached to the support table 30 is arranged on the front side S1 of the spindle 12, supports the rod-shaped workpiece W1 penetrating the spindle 12 so that it can slide in the Z-axis direction, and is driven to rotate around the spindle center line AX1 in synchronization with the spindle 12. The guide bush 32 is detachably provided on the support table 30. The presence of the guide bush that receives the load from machining such as cutting suppresses the deflection of the elongated workpiece, and high-precision machining is performed. When the guide bush shown in Figures 2A and 2B is used, the spindle table 10 is driven so that the spindle 12 moves in the Z-axis direction within the range S2 behind the guide bush 32. On the other hand, when the guide bush is used, the material from the spindle to the guide bush cannot be machined, so the remaining material becomes long. In addition, since the guide bush supports the outer periphery of the workpiece, the workpiece once machined cannot be moved back into the guide bush and then forward again for machining. Therefore, as shown in Figures 4A and 4B, the guide bush 32 can be removed from the support table 30. In this case, in order to shorten the distance from the spindle 12 to the tool rest 60, the headstock 10 is driven so that the spindle 12 moves in the Z-axis direction within a range that is on the front side S1 compared to when the guide bush is used.

An annular guide member 40 that supports the quill 11 movably in the Z-axis direction is detachably provided on the support base 30 from which the guide bush 32 has been removed. The guide member 40 shown in Figures 4A, 4B, etc. has a through hole 40a into which the quill 11 of the headstock 10 is inserted, and is attached to the support base 30. The guide member 40 attached to the support base 30 supports the quill 11 slidably in the Z-axis direction. A substantially rectangular parallelepiped positioning member 50 that contacts the outer peripheral surface of the guide member 40 is also attached to the support base 30. The guide member 40 and the positioning member 50 are attached to the surface of the rear side S2 of the support base 30.
Incidentally, it is preferable to use a sliding bearing for the guide member 40 which receives the load caused by machining such as cutting, but it is also possible to use various bearings such as a rolling bearing.

The tool rest 60 is supported by the support base 30, has a plurality of tools T1 attached thereto, and is movable, for example, in the X-axis direction and the Y-axis direction. The tools T1 include both fixed tools such as a turning tool that is fixed so as not to rotate, and rotating tools that rotate, such as a rotary drill.
In addition, a back headstock (counter headstock) having a back spindle (counter spindle) that releasably grips the workpiece W1 after front machining inserted in the Z-axis direction may be supported on the base 2.

As shown in Figures 2A and 2B, two rails 200 are installed on the base 2. The two rails 200 are guide rails for linear guides, and are arranged along the spindle center line AX1 at two locations in the Y-axis direction. Each rail 200 guides the rear bearing 110 and the front bearing 120 in the Z-axis direction. The rear bearing 110 and the front bearing 120 are attached to the headstock 10. The rail 200 shown in Figure 2B has a low-rigidity portion 212 that is slightly lower in rigidity due to overhanging with respect to the base 2. The low-rigidity portion 212 includes a moving range R2 of the front bearing 120 when the guide member is used as shown in Figure 4B, but does not include a moving range R1 of the front bearing 120 when the guide member is not used as shown in Figure 2B.
When the low rigidity portion 212 is supported by the base 2, the low rigidity portion 212 may be thin.

When the guide bush is used, the load caused by machining such as cutting is received by the guide bush 32. Here, as shown in FIG. 2B, etc., the low rigidity portion 212 of the rail 200 is not within the movement range R1 of the front bearing 120. Therefore, when the guide bush is used, the headstock 10 is supported with high precision by the rear bearing 110 and the front bearing 120.

When the guide bush is not in use, the load from machining such as cutting is received by the guide member 40. Here, as shown in FIG. 4B etc., the quill 11 of the headstock 10 is also supported by the guide member 40 provided on the support base 30. The low rigidity portion 212 of the rail 200 is easily deformed by the load from the front bearing 120, although it is very small. For this reason, the front bearing 120 has a large play when the guide member is in use, and the function of the front bearing 120 to support the headstock 10 is suppressed. Therefore, when the guide bush is not in use, the headstock 10 is supported with high precision by the rear bearing 110 and the guide member 40, which is located on the front side S1 of the front bearing 120.

The main parts, such as the base 2, the headstock 10, the drive unit 20, the support table 30, the guide bush 32, the guide member 40, the positioning member 50, the tool rest 60, and the rail 200, can be made of metal, for example.

Figure 5 shows a schematic example of the positional relationship between the quill 11, guide member 40, and positioning member 50 in a lathe 1 that uses a non-guide bush system. Figure 6 shows a schematic example of the positional relationship between the positioning member 50 and the guide member 40 in a cross section CS perpendicular to the spindle center line AX1. Figures 7A to 7C show a schematic example of the manner in which the positioning member 50 is attached to the support base 30.

The guide member 40 has a short, generally cylindrical shape along the center line AX2, and has an inner peripheral surface 41 with a circular cross section and an outer peripheral surface 42 with a circular cross section, centered on the center line AX2. The diameter of the inner peripheral surface 41 is slightly larger than the diameter of the outer peripheral surface 11a of the quill 11. As a result, the guide member 40 supports the quill 11 so that it can slide in the Z-axis direction. The guide member 40 has a plurality of screw insertion holes 43 for screwing the guide member 40 to the support base 30. The number of screw insertion holes 43 provided in the guide member 40 is not limited to 10 as shown in FIGS. 5 and 6, and may be 9 or less, or 11 or more. As shown in FIG. 7A, a counterbore 43a is formed in each screw insertion hole 43. This prevents the guide member 40 from being attached to the support base 30 in an upside-down state. The support base 30 has screw holes 33 formed at positions corresponding to the screw insertion holes 43. Each screw hole 33 is screwed into a screw SC<b>1 that passes through a screw insertion hole 43 .
The countersunk 43a is an example of a front/back discriminating section that can discriminate whether the guide member 40 is upside down with respect to the support base 30. Here, the state in which the guide member 40 is not upside down means that the countersunk 43a faces the opposite side to the support base 30, as shown in Figures 5, 7A, etc. The state in which the guide member 40 is upside down means that the guide member 40 faces the opposite direction in the Z-axis direction to the direction shown in Figure 7A, etc., and that the countersunk 43a faces the support base 30.

The outer peripheral surface 42 of the guide member 40 is in contact with the positioning members 50A and 50B. Here, the positioning member 50 is a general term for the positioning members 50A and 50B. In the following, when the positioning members 50A and 50B are described in common, they will simply be referred to as the positioning member 50. The positioning member 50 has a function of aligning the center line AX2 of the guide member 40 with the spindle center line AX1 by contacting the outer peripheral surface 42 of the guide member 40. The positioning member 50 has a plurality of screw insertion holes 53 in order to screw the positioning member 50 to the support base 30. The number of screw insertion holes 53 provided in the positioning member 50 is not limited to two as shown in Figures 5 and 6, and may be three or more. As shown in Figure 7B, the support base 30 has screw holes 34 formed at positions corresponding to each screw insertion hole 53. Each screw hole 34 is screwed into the screw SC2 that has passed through the screw insertion hole 43.

6, the positioning member 50 attached to the support base 30 and the guide member 40 attached to the support base 30 are in contact with each other at two contact points P1 and P2 that form a triangle TR with the center P3 of the guide member 40. The center P3 is the intersection point of the center line AX2 of the guide member 40 and the cross section CS. The contact point P1 is the contact point between the positioning member 50A and the guide member 40. The contact point P2 is the contact point between the positioning member 50B and the guide member 40.
Here, the surface of the positioning member 50 where the contact points P1 and P2 exist is referred to as the contact surface 51. The contact surface 51 is a flat surface. Therefore, the outer peripheral surface 42 of the guide member 40 and the contact surface 51 of the positioning member 50 are in linear contact along the center line AX2 of the guide member 40. When viewed in a cross section CS perpendicular to the spindle center line AX1, the outer peripheral surface 42 and the contact surface 51 are in point contact. By making the contact surface 51 a flat surface, the position of contact is limited to one point, and the position of the guide member 40 can be determined with high precision.

Since the center P3 and the contact points P1 and P2 form a triangle TR, when the operator presses the unfixed guide member 40 against the positioning member 50, the guide member 40 and the positioning member 50 come into contact at the contact points P1 and P2, and the center line AX2 of the guide member 40 coincides with the spindle center line AX1. Here, the interior angle θ of the center P3 in the triangle TR may be greater than 0° and less than 180°, and is preferably 90° to 140°. If the interior angle θ is 90° or more, the guide member 40 can be easily and stably pressed against both the positioning members 50A and 50B. If the interior angle θ is 140° or less, the position of the guide member 40 can be determined with high precision when the guide member 40 is pressed against the positioning members 50A and 50B. Therefore, if the interior angle θ is 90° to 140°, the center line AX2 of the guide member 40 can be positioned with even higher precision on the spindle center line AX1.

In addition, because the contact surface 51 of the positioning member 50 is flat, two contact points P1 and P2 between the positioning member 50 and the guide member 40 can be easily realized, and the center line AX2 of the guide member 40 can be easily positioned to the spindle center line AX1.

(3) Specific examples of attaching the positioning member to the support base:
First, an example of attaching a positioning member 50 to the support base 30 of the guide bush 32 will be described with reference to FIGS. 7A to 7C.
Fig. 7A illustrates a schematic diagram of a state in which the guide member 40 is attached in a state in which the positioning member 50 is not attached to the support base 30. Fig. 7B illustrates a schematic diagram of a state in which the positioning member 50 is attached to the support base 30 by contacting the guide member 40. Fig. 7C illustrates a schematic diagram of a state in which the positioning member 50 is fixed to the support base 30.

When attaching the positioning member 50 to the support table 30, it is necessary to fix it at a position where the center line AX2 of the guide member 40 coincides with the spindle center line AX1. Therefore, the work of attaching the positioning member 50 to the support table 30 may be performed by a skilled worker of the lathe manufacturer. Of course, the lathe operator may also attach the positioning member 50 to the support table 30. Hereinafter, the person who attaches the positioning member 50 to the support table 30 will be called the operator.
First, the operator places the guide member 40 outside the quill 11, and places the quill 11 in the through hole 40a of the guide member 40. Next, the operator advances the headstock 10, and while supporting the guide member 40 with his/her hand, holds the guide member 40 so that the center line AX2 of the guide member 40 is aligned with the spindle center line AX1. This state is shown in Fig. 7A. When the operator inserts the screws SC1 into the screw insertion holes 43 of the guide member 40 and screws them into the screw holes 33 of the support base 30, the guide member 40 is fixed to the support base 30.

After the guide member 40 is fixed, the worker may move the headstock 10 backward. Since the guide member 40 is fixed to the support base 30, the worker supports the positioning member 50 with his fingers and holds the positioning member 50 with the contact surface 51 of the positioning member 50 against the outer peripheral surface 42 of the guide member 40. This state is shown in FIG. 7B. While maintaining this holding state, the worker inserts screws SC2 into each screw insertion hole 53 of the positioning member 50 and screws them into the screw holes 34 of the support base 30, and the positioning member 50 is fixed to the support base 30 as shown in FIG. 7C.

Even if the lathe 1 is subsequently changed to the guide bush type, there is no need to remove the positioning member 50 from the support base 30. Below, a specific example of switching between the guide bush type and the non-guide bush type is described.

(4) Specific examples of switching between guide bush type and non-guide bush type:
When switching from the non-guide bush system shown in Figures 4B, 7C, etc. to the guide bush system shown in Figure 2B, etc., the operator moves the headstock 10 backward, removes the guide member 40 from the support base 30 by unscrewing the screw SC1, and attaches the guide bush to the support base 30. As shown in Figures 2A and 2B, the positioning member 50 is located in a position that does not interfere with the movement of the headstock 10 in the Z-axis direction, so there is no need to remove the positioning member 50 from the support base 30 even in the guide bush system.

Next, a specific example of switching from the guide bush type to the non-guide bush type will be described with reference to Figures 8A, 8B, 7C, etc.
Fig. 8A illustrates a schematic diagram of the guide bush 32 being removed from the support base 30. Fig. 8B illustrates a schematic diagram of the guide member 40 being attached to the support base 30 by abutting against the positioning member 50.

When switching from the guide bush type shown in FIG. 2B etc. to the non-guide bush type shown in FIGS. 4B, 7C etc., the operator performs the following operations.
First, the operator removes the guide bush 32 from the support base 30. This state is shown in FIG. 8A. Since the positioning member 50 is fixed to the support base 30 as shown in FIG. 8A, the operator holds the guide member 40 by hand and holds the guide member 40 with the outer circumferential surface 42 of the guide member 40 against the contact surface 51 of the positioning member 50 (positioning step ST1). This state is shown in FIG. 8B. Since the positioning member 50 shown in FIG. 8B remains attached to the support base 30 at the position shown in FIG. 7C, the position of the guide member 40 shown in FIG. 8B has not changed from the position of the guide member 40 attached to the support base 30 so that the center line AX2 coincides with the spindle center line AX1 as shown in FIGS. 7A and 7B. Therefore, there is no need to insert the quill 11 into the through hole 40a of the guide member 40 to align the center line AX2 of the guide member 40 with the spindle center line AX1. As shown in FIG. 8B, when the operator inserts a screw SC1 into each screw insertion hole 43 of the guide member 40 and screws it into the screw hole 33 of the support base 30, the positioning member 50 is fixed to the support base 30 with the center line AX2 aligned with the spindle center line AX1 as shown in FIG. 7C (installation process ST2).

As a result, it is no longer necessary to perform the burdensome task of centering, such as pushing up the heavy guide member 40. It is also no longer necessary to first position the guide member 40 on the outside of the quill 11. In other words, it is no longer necessary to perform the burdensome task every time the system is switched from the guide bush system to the non-guide bush system. Therefore, this example can reduce the workload of switching from the guide bush system to the non-guide bush system.
In addition, since the guide member 40 has the counterbore 43a, it is possible to determine whether the guide member 40 is in an upside-down state relative to the support base 30, and therefore the operator can attach the guide member 40 to the support base 30 in an uninverted state. As described above, when the guide member 40 is attached in an upside-down state relative to the support base 30, the guide member 40 needs to be machined with extremely high precision in order to match the position of the central axis AX2 in the upside-down state and in the uninverted state. Because of the counterbore 43a, the machining of the guide member 40 does not require high precision to match the position of the central axis AX2 in the upside-down state and in the uninverted state. Therefore, this specific example can reduce the cost of the guide member.

(5) Modifications:
The present invention contemplates various modifications.
For example, the quill 11 of the headstock 10 described above covers the outside of the spindle 12 up to near the front end of the spindle 12, but the positional relationship between the quill and the spindle in the direction of the spindle centerline can be changed as appropriate. For example, if the distance from the front end of the quill to the front end of the spindle is long, a spindle cover that covers the outside of the spindle from the front end of the quill to near the front end of the spindle may be attached to the front end of the quill.
In order to attach the positioning member 50 to the support base 30, a biasing means, for example, a spring, which presses the positioning member 50 toward the guide member 40 may be provided on the support base 30. In this case, since the biasing means presses the positioning member 50 against the guide member 40 when attaching the positioning member 50 to the guide member 40 as shown in Figures 7B and 7C, the operator can attach the positioning member 50 to the support base 30 without having to hold the positioning member 50 by hand.

The positioning member 50 described above is a substantially rectangular parallelepiped, but the shape of the positioning member is not limited to a substantially rectangular parallelepiped. Figures 9A to 9C are schematic diagrams showing modified examples of the positioning member 50 together with the guide member 40 in a cross section CS perpendicular to the spindle center line AX1. In the following modified examples, the same elements as in the above example are given the same reference numerals and detailed descriptions are omitted.

9A shows an example in which one positioning member 50 has two contact points P1 and P2. The positioning member 50 shown in FIG. 9A has a contact surface 51A having a contact point P1 and a contact surface 51B having a contact point P2. The two contact surfaces 51A and 51B are included in the contact surface 51 of the present technology. When the contact surfaces 51A and 51B are flat, the outer peripheral surface 42 of the guide member 40 and the contact surface 51 of the positioning member 50 are in linear contact along the center line AX2 of the guide member 40. In the example shown in FIG. 9A, the operator applies the outer peripheral surface 42 of the guide member 40 to the contact surfaces 51A and 51B of the positioning member 50, so that the center line AX2 of the guide member 40 is aligned with the spindle center line AX1, eliminating the need for a burdensome centering operation.

Figure 9B shows an example in which the contact surface 51 of the positioning member 50 is a concave curved surface with a radius of curvature larger than the radius of curvature of the outer peripheral surface 42 of the guide member 40 in a cross section CS perpendicular to the spindle center line AX1. In this case too, the outer peripheral surface 42 of the guide member 40 and the contact surface 51 of the positioning member 50 are in linear contact along the center line AX2 of the guide member 40. In the example shown in Figure 9B, the operator applies the outer peripheral surface 42 of the guide member 40 to the contact surface 51 of the positioning member 50, so that the center line AX2 of the guide member 40 is aligned with the spindle center line AX1.

Figure 9C shows an example in which the contact surface 51 of the positioning member 50 is circular in a cross section CS perpendicular to the spindle center line AX1. When the positioning member 50 is substantially cylindrical with its central axis along the spindle center line AX1 as its center, the outer peripheral surface 42 of the guide member 40 and the contact surface 51 of the positioning member 50 make linear contact along the center line AX2 of the guide member 40. When the positioning member 50 is substantially spherical, the outer peripheral surface 42 of the guide member 40 and the contact surface 51 of the positioning member 50 make point contact. In these examples, the operator applies the outer peripheral surface 42 of the guide member 40 to the contact surface 51 of the positioning member 50, so that the center line AX2 of the guide member 40 aligns with the spindle center line AX1.

In addition, while the inner peripheral surface 41 and the outer peripheral surface 42 of the above-described guide member 40 have a circular cross section, the inner peripheral surface and the outer peripheral surface of the guide member are not limited to being circular in cross section. Figure 10 illustrates an example of a guide member 40 in which the inner peripheral surface 41 and the outer peripheral surface 42 are both non-circular in cross section in a cross section CS perpendicular to the spindle center line AX1.

The inner circumferential surface 41 of the guide member 40 shown in FIG. 10 has multiple recesses 41a recessed in a direction away from the center line AX2. In this case, too, the inner circumferential surface 41 has a diameter slightly larger than the diameter of the outer circumferential surface 11a of the quill 11 excluding the recesses 41a, so that the guide member 40 can support the quill 11 so that it can slide in the Z-axis direction.

The outer peripheral surface 42 of the guide member 40 shown in FIG. 10 has a rectangular cross section. In this case, too, by appropriately attaching the positioning member 50 to the support base 30, the guide member 40 can be positioned so that the positioning member 50 aligns the center line AX2 with the spindle center line AX1. FIG. 10 shows that three positioning members 50A, 50B, and 50C are arranged to position the guide member 40 with high precision. Of course, the three positioning members 50A, 50B, and 50C are included in the positioning member 50 of the present technology.

(6) Conclusion:
As described above, according to the present invention, it is possible to provide a technology for lathes and the like that reduces the work of switching from a guide bush type to a non-guide bush type through various aspects. Of course, even if the technology is composed only of the constituent elements according to the independent claims, the basic functions and effects described above can be obtained.
In addition, configurations in which the configurations disclosed in the above examples are substituted with each other or the combination is changed, configurations in which the configurations disclosed in the publicly known techniques and the above examples are substituted with each other or the combination is changed, etc. The present invention also includes these configurations.

1...Lathe,
10... headstock, 10a... main body, 11... quill, 11a... outer circumferential surface, 12... spindle,
20... Drive unit,
30: Support base; 31: Through hole; 32: Guide bush; 33, 34: Screw holes;
40: guide member; 40a: through hole; 41: inner peripheral surface; 42: outer peripheral surface;
43...screw insertion hole, 43a...countersink,
50, 50A, 50B, 50C...positioning members,
51, 51A, 51B...contact surfaces, 53...screw insertion hole,
60...Tool holder,
AX1: spindle center line, AX2: center line,
CS...cross section,
D1: spindle center line direction,
P1, P2...contact points, P3...center,
S1...front side, S2...rear side,
SC1, SC2...Screw,
ST1: Positioning step, ST2: Mounting step,
TR...triangle,
W1...Work.

Claims (4)

A spindle that grips a workpiece;
a headstock having a quill arranged on the outside of the spindle with the center line of the spindle as the center, and rotatably supporting the spindle;
a drive unit that moves the headstock in a direction along the center line of the headstock;
a support base on which a guide bush that slidably supports the workpiece is removably provided in front of the spindle;
a guide member attached to the support base from which the guide bush has been removed, and supporting the quill slidably in the direction of the center line of the spindle;
a positioning member attached to the support base and adapted to align a center line of the guide member with a center line of the spindle ;
A lathe, in a cross section perpendicular to the center line of the spindle, the positioning member attached to the support base and the guide member attached to the support base are in contact at two contact points that form a triangle with the center of the guide member . 2. The lathe according to claim 1 , wherein the surface of the positioning member on which the contact point exists is a flat surface or a concave curved surface having a radius of curvature larger than a radius of curvature of the outer peripheral surface of the guide member in the cross section. 3. The lathe according to claim 1, wherein the guide member has a front / back discriminating portion capable of determining whether the guide member is upside down with respect to the support base. A spindle that grips a workpiece;
a headstock having a quill arranged on the outside of the spindle with the center line of the spindle as the center, and rotatably supporting the spindle;
a drive unit that moves the headstock in a direction along the center line of the headstock;
a support base on which a guide bush that slidably supports the workpiece is removably provided in front of the spindle;
a guide member that is attached to the support base from which the guide bush has been removed, and that supports the quill slidably in a direction toward a center line of the spindle,
a positioning step of contacting the guide member with a positioning member attached to the support base, the positioning member being configured to align a center line of the guide member with a center line of the spindle;
and a mounting step of mounting the guide member abutted against the positioning member to the support base from which the guide bush has been removed,
A method for mounting a guide member of a lathe, in a cross section perpendicular to the center line of the spindle, the positioning member attached to the support base and the guide member attached to the support base are in contact at two contact points that form a triangle with the center of the guide member .

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