WO2003059558A1

WO2003059558A1 - Guide bush

Info

Publication number: WO2003059558A1
Application number: PCT/JP2003/000217
Authority: WO
Inventors: Shigeo Hasegawa; Yoshihiro Nojima
Original assignee: Citizen Watch Co., Ltd.
Priority date: 2002-01-15
Filing date: 2003-01-14
Publication date: 2003-07-24
Also published as: CN1298467C; CN1496293A; JP3945752B2; JP2003211303A

Abstract

A guide bush (10) has a bar member support (14) adjacent one axial end of a base (12). The bar member support (14) comprises a diametrically elastically deformable outer sleeve portion (16) integrally connected to the base (12), a plurality of inner sleeve piece members (20) disposed inside the outer sleeve portion (16), made of hard material and cooperating with each other to form a cylindrical bar member support surface (18), and an elastic member (22) for elastically holding the inner sleeve piece members (20) in the position where they form the bar member support surface (18). The elastic member (22) comprises elastic connecting elements (34) each interposed between adjacent inner sleeve piece members (20) to elastically interconnect the latter, and elastic intermediate sleeves (36) each interposed between the outer sleeve portion (16) and each inner sleeve piece member (20) to elastically support these inner sleeve piece members (20) from outside. The elastic connecting elements (34) may be formed of liquid gaskets.

Description

Description Guide Push Technical Field

The present invention relates to a guide bush for supporting a bar being turned in the vicinity of a portion to be processed. Further, the present invention relates to an automatic lathe provided with such a guide bush. Background art

In machine tools that can perform various types of automatic turning, such as NC lathes (collectively referred to as “automatic lathes” in this specification), a rod-like shape that is installed on a lathe stand near the position where a tool is used to perform machining and is gripped by a spindle There is known a material provided with a guide bush as an auxiliary support device for supporting a material to be processed (hereinafter, referred to as a bar) in the vicinity of a processing portion at a tip end thereof. The guide bush has a hollow cylindrical rod support that can be elastically deformed in the radial direction. The rod support supports the bar being turned so that the processed part does not run out. It enables high precision processing of products. Conventionally, in automatic lathes, a fixed guide bush that is fixedly arranged on a bar that rotates at high speed during turning and a rotary guide bush that rotates at high speed together with the bar are appropriately selected. It is used.

In addition, in conventional automatic lathes, the tool cutting edge is arranged at a desired position in the longitudinal direction of such a machining length part in order to supply the machining length part at the tip of the bar material as a product to the machining operation position. For this purpose, it is well known that the main shaft gripping the bar moves in the axial direction. In this automatic lathe, the guide bush is fixed or rotary. Even in the form of displacement, the bar sent by the axial movement of the spindle while the bar is centered and supported on the bar support (that is, the bar axis is supported so as to match the rotation axis) is also used. It is necessary to be able to support while accurately guiding in the axial direction. Conventionally, before the start of machining, a bar (round or square) to be machined is inserted into the guide bush, the bar support is elastically deformed, and its inner diameter is fine-tuned to match the outer diameter of the bar. By doing so, it is possible to achieve both centering support and axial guide support of the bar.

In this type of guide bush, the bar support is made up of a two-layer structure consisting of an outer cylinder and an inner cylinder, and the outer diameter of the bar to be processed is changed, and the inner peripheral surface of the bar support (ie, the bar support) is used. A guide bush has been proposed in which the inner cylinder can be replaced as appropriate according to the degree of wear of the surface (Japanese Patent Laid-Open No. 2001-138210). See 3 10 102 A)). This guide bush supports different types of rods (round bar, square bar) with various outer diameters by replacing only the inner cylinder as necessary while mounted on an automatic lathe. In addition, it is possible to quickly cope with a decrease in machining accuracy caused by wear of the bar supporting surface. Furthermore, if the inner cylinder is made of a material having excellent self-lubricating properties, the gap between the bar support surface of the inner cylinder and the outer peripheral surface of the bar to be processed is substantially eliminated, and the rod is fed in the axial direction when the rod is fed. It is possible to manufacture high-quality products by reducing as much as possible the damage on the outer peripheral surface of the rod caused by friction with the inner cylinder.

In the conventional guide bush having the above-described two-layered bar supporting portion, a general “slit” is used so that the inner diameter of the bar supporting portion can be finely adjusted according to the outer diameter of the bar to be processed. While the "structure" was formed in the outer cylinder, the inner cylinder was provided with the desired elasticity so that the diameter of the inner cylinder could be expanded or contracted. Such an inner cylinder having elasticity is particularly suitable for the material itself. When composed of a relatively soft material, there is a risk that the bar support surface will wear due to friction with the bar when the bar is fed in the axial direction. In particular, when a `` pulled material '' drawn to a specified diameter is used as it is as the bar to be processed, the inner cylinder may not be used due to the low external dimension accuracy of the drawn material or the surface roughness. There is a concern that wear of the inner cylinder is likely to occur, and as a result, the frequency of replacing the inner cylinder will increase. Disclosure of the invention

It is an object of the present invention to provide a guide bush installed on an automatic lathe, which has a multi-layered bar supporting portion capable of quickly changing the outer diameter of a bar to be processed and abrasion of a bar supporting surface, Yet another object of the present invention is to provide a guide bush capable of significantly improving the wear resistance of a bar supporting surface. To provide a high-performance automatic lathe provided with such a guide bush. It is in.

In order to achieve the above object, the present invention provides a guide push provided with a hollow cylindrical base and a hollow cylindrical rod support provided in contact with one end of the base in the axial direction! The support portion is provided with an outer cylinder portion integrally connected to the base portion and an inner cylinder portion, each of which is formed of a hard material and cooperates with each other to form a cylindrical bar support surface. A plurality of inner cylinder piece members to be formed, and a sex member for sexually holding the plurality of inner cylinder piece members at a position forming a bar support surface inside the outer cylinder portion are provided. Provide a guide bush with features.

In a preferred aspect, the elastic member includes a flexible connection element interposed between adjacent inner cylinder piece members to elastically connect the inner cylinder piece members to each other.

In this configuration, the flexible connecting element is formed from a liquid gasket. Is advantageous.

In another preferred aspect, the elastic member includes an elastic intermediate cylinder interposed between the outer cylindrical portion and each of the plurality of inner cylindrical piece members to elastically support the inner cylindrical piece members from the outside. Is done.

In this configuration, it is advantageous that the elastic intermediate cylinder is made of a soft material that can be compressed and elastically deformed between the outer cylinder part and the plurality of inner cylinder pieces.

In yet another preferred aspect, the elastic member includes an elastic support element that engages with the plurality of inner cylinder pieces and elastically supports the inner cylinder pieces from the inside.

In this case, the elastic support element can be formed of a spring that urges the plurality of inner cylinder piece members radially outward.

It is advantageous that at least a portion of each of the plurality of inner cylinder piece members that forms the bar support surface is made of ceramics.

In the above guide bush, the outer cylindrical portion of the bar supporting portion can be elastically deformed in the radial direction, and with the elastic deformation of the outer cylindrical portion, the inner diameter of the bar supporting surface formed by the plurality of inner cylindrical piece members is reduced. Can be configured to change.

Further, according to the present invention, there is provided an automatic lathe in which a guide bush having the above-described various features is installed in the vicinity of a bar working position. BRIEF DESCRIPTION OF THE FIGURES

The above and other objects, features and advantages of the present invention will become more apparent from the following description of preferred embodiments in conjunction with the accompanying drawings. In the accompanying drawings,

FIG. 1A is a view showing a guide bush according to a first embodiment of the present invention, and is a cross-sectional view taken along line I-I of FIG. 1B, FIG. 1B is an axial end view of the guide bush of FIG. 1A,

FIG. 2A is a diagram showing a base and an outer cylinder portion of the guide bush of FIG. 1A, and is a cross-sectional view taken along a line II_II of FIG. 2B.

Fig. 2B is an axial end view of the base and the outer cylinder of Fig. 2A, and Fig. 3A is a view showing the inner cylinder structure of the guide push of Fig. 1A.

A cross-sectional view along the line I I I-I I I in FIG. 3B,

FIG. 3B is an axial end view of the inner cylinder structure of FIG. 3A,

Fig. 4A is a diagram showing the elastic intermediate における in the guide bush of Fig. 1.

, A cross-sectional view along line IV—IV in FIG. 4B,

FIG. 4B is an axial end view of the elastic intermediate cylinder of FIG. 4A,

Fig. 5 is a sectional view showing the main part of an automatic lathe equipped with the guide bush of Fig. 1,

FIG. 6A is a view showing a guide bush according to a second embodiment of the present invention, and is a cross-sectional view taken along line VI-VI of FIG. 6B,

FIG. 6B is an axial end view of the guide bush of FIG. 6A.

FIG.7A is a view showing a base and an outer cylinder part in the guide push of FIG.6A, and is a cross-sectional view taken along a line VII-VII of FIG.7B.

FIG. 7B is an axial end view of the base and the outer cylinder part of FIG. 7A, and FIG. 8A is a view showing a guide bush according to the third embodiment of the present invention, taken along line VIII-VIII of FIG. 8B. Cross section,

FIG. 8B is an axial end view of the guide bush of FIG. 8A,

FIG. 9A is a diagram showing a plurality of inner cylinder piece members in the guide bush of FIG. 8A, and a cross-sectional view taken along line IX_IX of FIG. 9B;

9B is an axial end view of the plurality of inner cylinder piece members of FIG. 9A, FIG. 10 is a front view of an elastic support element of the guide bush of FIG. 8A,

Fig. 11A shows the base and outer cylinder of the guide bush shown in Fig. 8A. FIG. 11B is a cross-sectional view taken along a line XIA-XIA in FIG. 11B, and FIG. 11B is a cross-sectional view taken along a line XIB-XIB of a base portion and an outer cylinder portion in FIG. 11A. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, identical or similar components are denoted by common reference numerals.

Referring to the drawings, FIGS. 1A and 1B show a guide bush 10 according to a first embodiment of the present invention. The guide bush 10 is a hollow cylindrical auxiliary support device that supports the bar gripped by the main spindle near the part to be machined at the end of an automatic lathe. It is installed on a machine stand. The guide bush 10 of the first embodiment can be applied to both a rotary guide bush and a fixed guide bush.

The guide bush 10 is provided adjacent to a hollow cylindrical base 12 and one end in the axial direction of the base 12, and is a hollow cylinder for centering and supporting a bar machined by an automatic lathe so as to be capable of being axially fed. And a rod support portion 14 having a shape of a bar. The base 12 is an open end face on the rear end in the axial direction (left end in the figure) away from the bar support section 14 for introducing the bar sent from the main spindle on the lathe machine of the automatic lathe. A cylindrical inner peripheral surface 12b adjacent to the open end surface 12a for receiving the bar in a non-contact manner, and a male screw portion 12c on the opposite outer peripheral surface. It is formed.

The bar support portion 14 is provided inside the outer cylinder portion 16 which is integrally connected to the base portion 12 and which can be elastically deformed in the radial direction, and each is formed of a hard material. A plurality of inner cylinder piece members 20 which together form a substantially cylindrical rod support surface 18 together with each other; An elastic member 22 for elastically holding the member 20 at a position where the bar supporting surface 18 is formed inside the outer cylindrical portion 16 is provided. The bar support 14 has a center axis 14a that matches the center axis of the bar to be supported, and supports the centering of the bar (i.e., aligns the bar axis with the axis of rotation during turning). Support).

As shown in FIG. 1A, FIG. 1B, FIG. 2A, and FIG. 2B, a plurality of outer cylinder portions 16 are integrally connected to the base portion 12 at respective base ends 24a (the illustrated embodiment). 3) vertical split pieces 24. The vertical split pieces 24 are adjacent to each other in the circumferential direction via a plurality of (three in the illustrated embodiment) slits 26 provided at equal intervals in the circumferential direction of the outer cylinder portion 16. Will be placed. The slits 26 support the rod material from the open end surface 16a of the outer cylindrical portion 16 at the front end in the axial direction (right end in the figure) away from the base 12 to the base 12. It is formed parallel to the central axis 14a of the part 14 and radially with respect to the central axis 14a. Thus, each of the vertical split pieces 24 can be elastically deformed into a leaf spring shape in the radial direction of the outer cylindrical portion 16 with the base end 24 a as a fulcrum.

The three vertical split pieces 24 constituting the outer cylinder part 16 each have an inner surface 24 b curved in an arc shape, and the inner surfaces 24 b cooperate with each other to form the outer cylinder part 16. Constitutes a substantially cylindrical inner peripheral surface. The inner peripheral surface defines a central axis that matches the central axis 14a of the bar support portion 14 in a state where the vertical split pieces 24 are not elastically deformed. Further, each vertical split piece 24 is formed with a flange portion 28 bulging radially outward, adjacent to its free end, that is, the opening end face 16a of the outer cylindrical portion 16. A pressure receiving surface 28a that extends in a tapered shape toward the base end 24a is formed on the outer peripheral surface of the flange portion 28 of each vertical split piece 24.

Further, each vertical split piece 24 of the outer cylindrical portion 16 is formed with a claw 30 projecting radially inward from the inner surface 24b along the opening end surface 16a. The claws 30 formed on the outer cylinder portion 16 each have a locking surface 30a extending in a tapered shape toward the opening end surface 16a, and cooperate with each other to form a substantially annular locking portion. Form the structure.

As shown in FIG. 1A, FIG. 1B, FIG. 3A and FIG. 3B, the guide push 10 has three inner parts corresponding to the three vertically split pieces 24 of the outer cylinder part 16. The tubular piece member 20 is incorporated in the bar support part 14. Each cylindrical piece member 20 has an outer surface 20a extending in an arc shape facing the inner surface 24b of the corresponding vertical split piece 24 of the outer cylindrical portion 16 via a gap, and an outer surface 20a. It has an inner surface 20b extending in an arc shape on the opposite side, and a pair of side surfaces 20c extending flat between the outer surface 20a and the inner surface 20b. The three cylindrical piece members 20 have a relative arrangement in which the respective inner surfaces 2 O b are substantially located on a common cylindrical surface, and the respective side surfaces 20 c face each other with a gap therebetween. And are combined into a cylindrical shape. In this state, the inner surfaces 20b of the inner cylinder piece members 20 cooperate with each other to center and support the bar so that the bar can be fed in the axial direction. Having 1 8 a).

Each inner cylinder piece member 20 has a flange portion 32 protruding radially outward, adjacent to one end face 20 d in the axial direction. An engagement surface 32a that extends in a tapered shape toward one end surface 20d in the axial direction is formed on the flange portion 32 of each inner cylinder piece member 20. A groove 32b extending in the axial direction along the radially outer end face is formed in the flange portion 32 of one inner cylinder piece member 20.

Examples of the hard material that can be suitably used for each inner cylinder piece member 20 include ceramics. In this case, the portion including the inner surface 2 0 b which at least forms a bar supporting surface 1 8, alumina (A l ₂ O _3), Jirukonia (Z r 0 _2), silicon nitride (3 1 ^ _4), carbide Engineering ceramics with excellent abrasion resistance, such as silicon (3iC) Can be made. In particular, in addition to the wear resistance and surface smoothness required for the rod supporting surface 18, it is also possible to prevent the inner cylinder piece member 20 from being damaged by repeating insertion and delivery of the rod as much as possible. From the viewpoint, it is advantageous to manufacture from zirconia ceramics having excellent impact strength and toughness. According to such a configuration, in particular, the durability of each inner cylinder piece member 20 can be significantly improved.

The plurality of elastic members 22 are interposed between the opposing side surfaces 20c of the inner cylinder piece members 20 adjacent in the circumferential direction to elastically connect the inner cylinder piece members 20 to each other (FIG. 3) elastic connection elements 3 4. In the guide bush 10, each of the elastic connecting elements 34 is a liquid gasket which is substantially entirely filled in a space between the opposing side surfaces 20 c of the adjacent inner cylinder piece 20. Formed from Liquid gaskets are known as sealants for sealing between joining surfaces of various machine parts. As such, they exhibit the required adhesiveness to the joining surfaces after curing, and are also desirable in a cured state. Can maintain the elasticity. As a liquid gasket that can be suitably used for the elastic connecting element 34, for example, “# 1215 liquid gasket” available from Three Bond Co., Ltd. (Tokyo, Japan) can be mentioned.

The elastic connecting element 34 connects the inner cylinder pieces 20 adjacent to each other in the circumferential direction so as to be relatively displaceable, so that three inner cylinder pieces are formed inside the outer cylinder portion 16 of the rod supporting portion 14. The members 20 are prevented from being separated from each other, and the inner cylinder piece members 20 are held elastically at positions where the cylindrical bar support surfaces 18 are formed. Further, when a pressing force inward in the radial direction is applied to the outer surfaces 20 a of the three inner cylinder piece members 20, respectively, the elastic connection elements 34 face the inner cylinder piece members 20 adjacent to each other. Various elastic deformations occur between the sides 20 c. Along with this, the three inner cylinder piece members 20 are brought into contact with each other until the opposing side faces 20 c are pressed against each other via the elastic connecting element 34. As a result, the inner diameter of the rod supporting surface 18 formed by the inner surface 20 b of the inner cylinder piece 20 decreases. When the pressing force on the outer surface 20a of each inner cylinder piece 20 is released, each inner cylinder piece 20 returns to the initial position under the elastic restoring force of the elastic connection element 34, and the rod The inner diameter of the material support surface 18 is restored.

The elastic connecting element 34 made of a liquid gasket is installed so as to seal the space between the opposing side surfaces 20 c of the inner cylindrical piece member 20 as a whole as shown in the figure. For example, it is possible to prevent chips from entering a space between the inner cylindrical piece members 20 during a bar turning operation by an automatic lathe described later. However, the arrangement of the elastic connecting elements 34 is not limited to this. For example, the elastic connection elements 34 are locally installed at a desired position in a space between the inner cylinder piece members 20 so that the two inner cylinder piece members 20 can be combined. It is also possible to adopt a configuration of interconnecting. In addition, not only the liquid gasket but also individual elastic connecting elements 34 can be constituted by a combination of an elastic body such as a rubber plate and an adhesive.

The elastic member 22 is further provided between the outer cylinder portion 16 and the three inner cylinder piece members 20 to elastically support the inner cylinder piece member 20 from outside. A cylinder 36 is provided. As shown in FIG. 1A, FIG. 1B, FIG. 4A and FIG. 4B, the elastic intermediate cylinder 36 is a cylindrical member, and the inner surface 2 of the three vertical split pieces 24 of the outer cylinder portion 16 is formed. 4b, a substantially cylindrical outer surface 36a to be in contact with the outer surface 36a, and a cylindrical inner surface to be in contact with the outer surfaces 20a of the three inner cylinder piece members 20 on the opposite side of the outer surface 36a. 3 6 b. A plurality (three in the illustrated embodiment) of slits 38 extending linearly in the axial direction along the outer surface 36 a of the elastic intermediate cylinder 36 are formed at regular intervals in the circumferential direction. You. The slits 38 open on the outer surface 36a over the entire length of the elastic intermediate cylinder 36 in the axial direction, and separate from the inner surface 36b (that is, without opening on the inner surface 36b). ) It is formed radially. That As a result, the elastic intermediate cylinder 36 has three arc-shaped wall portions 40 and three thin connecting portions that integrally interconnect the arc-shaped wall portions 40 in the circumferential direction along the respective inner surfaces. 4 2 are formed. In addition, a groove 44 extending in the axial direction along the outer surface is formed in one arc-shaped wall portion 40.

When a pressing force inward in the radial direction is applied to the outer surface 36 a of the flexible intermediate cylinder 36, stress concentrates on the three connecting portions 42, and the connecting portions 42 become Each elastically deforms variously. Along with this, the three arc-shaped wall portions 40 are displaced radially inward until the adjacent arc-shaped wall portions 40 come into contact with each other. As a result, the inner surface 36 b of the elastic intermediate cylinder 36 is distorted from the original cylindrical shape, and as a result, the substantial inner diameter of the elastic intermediate cylinder 36 is reduced. When the pressing force on the outer surface 36a of the elastic intermediate cylinder 36 is released, each arcuate wall portion 40 returns to the initial position under the elastic restoring force of each connecting portion 42, and the elastic intermediate cylinder 36 The inner diameter of 6 is restored.

The elastic intermediate cylinder 36 applies the radially inward pressing force applied to each vertical split piece 24 of the outer cylindrical portion 16 to the corresponding inner cylinder located radially inward of each vertical split piece 24. It works so as to reliably transmit to the one member 20. The elastic intermediate cylinder 36 supports the plurality of inner cylinder piece members 20 from the outside in the radial direction, thereby forming the inner cylinder piece members 20 into a cylindrical rod support surface 18. Hold elastically in position. Further, the elastic intermediate cylinder 36 receives adjacent pressures between the three vertical split pieces 24 of the outer cylinder portion 16 and the three inner cylinder piece members 20 to receive the pressure from both. Each arc-shaped wall portion 40 itself has such a degree of flexibility that it can be compressed and elastically deformed within a range until the wall portions 40 contact each other. As a suitable soft material of the elastic intermediate cylinder 36 capable of exhibiting such characteristics, for example, a fluororesin engineering pipe known as “Tarite B” in the field of bearing materials and the like is known. Resin materials such as plastics can be used.

The guide bush 10 is manufactured by separately manufacturing the above-described various components and then assembling as follows.

First, a push body integrally having the base portion 12 and the outer cylindrical portion 16 of the bar support portion 14 is manufactured from a desired metal material through a cutting step or the like. Therefore, an elastic intermediate cylinder 36 integrally molded from a resin material such as “Tarkai B” through an injection molding process or the like is formed with the outer surface 36 a being the inner surface 2 4 of each vertically split piece 24 of the outer cylinder portion 16. The vertical split pieces 24 and at least one of the elastic intermediate cylinders 36 are elastically deformed and fitted into the outer cylindrical portion 16 so as to be in close contact with b. At this time, the vertical split pieces 24 of the outer cylindrical portion 16 and the arc-shaped wall portions 40 of the elastic intermediate cylinder 36 are aligned with each other, and project from the inner surface 24b of one vertical split piece 24. Insert the detent 46 (Fig. 1A) into the groove 44 of the elastic intermediate cylinder 36. As a result, the elastic intermediate cylinder 36 and the rotation of the elastic intermediate cylinder 36 are stopped at a predetermined position inside the outer cylinder section 16 with the rotation of the elastic intermediate cylinder 36 and the outer cylinder section 16 reduced. At least one is held under elastic restoring force.

On the other hand, three inner cylinder piece members 20 each formed from a hard material such as zirconium ceramics are joined in a cylindrical shape by the elastic connecting element 34 as described above to produce an inner cylinder structure. . This inner cylinder structure is attached to the inner surface 36 b of the elastic intermediate cylinder 36 fitted into the outer cylinder portion 16 by each inner cylinder piece member.

The outer cylinder part 16 and the elastic intermediate cylinder are placed so that the outer surface 20

While elastically deforming at least one of the inner cylinder structure 36 and the inner cylinder structure (mainly the elastic connecting element 34), it fits inside the outer cylinder portion 16 and the elastic intermediate cylinder 36. At this time, each vertical split piece 24 of the outer cylinder part 16 and each arc-shaped wall part 40 of the elastic intermediate cylinder 36 and each inner cylinder piece member 20 of the inner cylinder structure are aligned with each other. The second detent 4 8 (Figure 1A) projecting from the inner surface 24b of one vertical split piece 24 is connected to the flange of one inner cylinder piece member 20. Insert into groove 32b formed in part 32. As a result, the inner cylinder structure is positioned at a predetermined position inside the outer cylinder part 16 and the elastic intermediate cylinder 36 in a state where rotation of all the inner cylinder piece members 20 with respect to the outer cylinder part 16 is prevented. At least one of the inner cylinder structure and the outer cylinder portion 16 is held under elastic restoring force.

When the guide bush 10 is properly assembled in this way, the three inner cylinder piece members 20 of the inner cylinder structure have the center axis 18 a of the bar supporting surface 18 formed by them, and It is kept in a state that matches the central axis 14 a of the part 14. In addition, the engagement surface 32 a of the flange portion 32 formed on each inner cylinder piece member 20 of the inner cylinder structure is engaged with the claw 30 formed on each vertically split piece 24 of the outer cylinder portion 16. The inner cylindrical piece member 20 is closely contacted with the surface 30 a, and the axial end surface 20 d of each inner cylindrical piece member 20 is disposed on the substantially same plane adjacent to the open end surface 16 a of the outer cylindrical portion 16. In this state, the inner cylinder structure is prevented from unintentionally protruding from the predetermined position inside the outer cylinder portion 16 to the outside of the outer cylinder portion 16. In addition, the elastic intermediate cylinder 36 is disposed so as to be substantially shielded by the flange portion 32 of each inner cylinder piece member 20 at a position separated from the opening end face 16 a of the outer cylinder portion 16. As a result, the elastic intermediate cylinder 36 made of a relatively soft material is isolated from the chips scattered during the turning process, so that damage is prevented.

In the guide bush 10, the vertical split pieces 24 of the outer cylinder part 16, the inner cylinder piece members 20 of the inner cylinder structure, and the respective arc-shaped wall parts 40 of the elastic intermediate cylinder 36 are arranged in the circumferential direction. They may be arranged offset from each other. Also, assuming that the outer cylinder part 16, the inner cylinder structure and the elastic intermediate cylinder 36 can generate the intended elastic deformation, the vertical split piece 24 of the outer cylinder part 16 and the inner cylinder structure The numbers of the inner cylinder piece member 20 and the arc-shaped wall portion 40 of the elastic intermediate cylinder 36 may be different from each other, or may be various numbers other than three. In the guide bush 10 having the above configuration, when an external force is applied inward in the radial direction to the three vertical split pieces 24 of the outer cylindrical portion 16, each vertical split piece 24 is elastically deformed, and at the same time, each vertical split piece 24 is deformed. An external force is applied radially inward from each vertical split piece 24 to the outer face 36 a of the elastic intermediate cylinder 36 in contact with the inner face 24 b of the split piece 24, and as described above, The elastic intermediate cylinder 36 is elastically deformed and its substantial inner diameter is reduced. Accordingly, an external force is applied radially inward from the elastic intermediate cylinder 36 to the outer surfaces 20a of the three inner cylinder piece members 20 that are in contact with the inner surface 36b of the elastic intermediate cylinder 36. As a result, as described above, under the elastic deformation of the elastic connecting element 34, the inner diameter of the bar supporting surface 18 formed by the inner surface 20b of the inner cylinder piece 20 is reduced. At this time, at the same time, from the engaging surface 30 a of the claw 30 formed on each of the vertical split pieces 24 of the outer cylinder part 16, the engaging surface 3 of the flange part 3 2 formed on each inner cylinder piece member 20 is formed. A pressing force is directly applied to 2a, and the pressing force also reduces the inner diameter of the bar supporting surface 18. '' From this state, when the radial external force of the outer cylinder part 16 to each vertical split piece 24 is reduced, each vertical split piece 24 is elastically restored, and accordingly the elastic intermediate cylinder 36 and the elastic connection The element 34 recovers elastically and the inner diameter of the bar support surface 18 increases (restores). While the inner diameter of the bar supporting surface 18 decreases and increases, the three inner cylinder pieces 20 move the center axis 18 a of the bar supporting surface 18 a of the bar supporting portion 14. Displaces in the radial direction while maintaining the state of alignment with the center axis 14a. As described above, in the guide bush 10, by adjusting the external force, ie, the pressing force, applied radially inward to the bar support portion 14, the bar formed by the three inner cylinder piece members 20 is adjusted. The inner diameter of the support surface 18 can be adjusted.

In the guide bush 10, the inner diameter of the bar support surface 18 formed by the three piece members 20 is set to be supported (processed) while the guide bush 10 is in an inactive state. Larger than the outside diameter of Is set to Then, before starting the actual machining operation in which the guide bush 10 is put into the working state, the target bar is inserted into the bar support portion 14, and the inner diameter of the bar support surface 18 is changed as described above. By making fine adjustments in accordance with the outer diameter of the bar, a desired fine gap of the order of μm is obtained between the bar support surface 18 and the outer peripheral surface of the bar. The guide bush 10 can center and support the bar so that it can be fed in the axial direction by securing such a fine gap in the operating state.

Here, when a “pulled material” with low external dimensional accuracy, which has been drawn to a specified diameter and has low external dimensional accuracy, is used as it is as a bar to be supported (processed), the above is applied to the minimum outer diameter part of the bar. The inner diameter of the rod supporting surface 18 is finely adjusted so that a minute gap is formed. In this state of operation, while the bar supported on the guide bush 10 is fed in the axial direction, the friction between the bar supporting surface 18 and the outer peripheral surface of the bar increases due to the increase in the outer diameter of the bar. Since the vertical split pieces 24 of the outer cylinder part 16 cannot be displaced radially outward, the respective arc-shaped wall parts 40 of the elastic intermediate cylinder 36 are themselves formed as the outer cylinder part 16.を受け Receives pressure with the cylinder structure to deform elastically as described above. As a result, each inner cylinder piece member 20 of the inner cylinder structure is displaced radially outward while elastically deforming the elastic coupling element 3.4, and the inner diameter of the rod support surface 18 is changed to the outer diameter of the rod. Expands passively to size. In this way, the guide bush 10 can center and support a rod made of a drawn material so that it can be fed in the axial direction. In addition, at this time, since each inner cylinder piece member 20 is formed of a hard material, the wear resistance of the rod supporting surface 18 is significantly improved, and each inner cylinder piece member 2 resulting from friction with the rod material is improved. The progress of wear of 0 can be suppressed as much as possible.

In the guide push 10 having the above configuration, the inner cylinder structure and the elastic intermediate cylinder 36 can be removed from the outer cylinder portion 16 as necessary by a procedure reverse to the above-described assembly procedure. Therefore, the outer diameter of the bar to be supported When trying to change the inner diameter of the bar support part 14 in response to a change in the method, the inner cylinder structure that was previously installed must be replaced with another inner cylinder with a different inner diameter of the bar support surface 18. What is necessary is just to replace it with a structure. Therefore, when processing different types of bars (round bars and square bars) with various outer diameters using an automatic lathe equipped with Guide Push 10, the inner diameter corresponding to these different types of bars is required. Various internal cylinder structures are prepared in advance, and the bush body consisting of the base 12 and the outer cylinder 16 is mounted on an automatic lathe. As a result, high-precision processing of different types of bars can be performed sequentially. Also, when the inner surface 20b of each inner cylinder piece member 20 is worn out due to a long working operation, the bush body is not replaced, and only the inner cylinder structure may be appropriately replaced. Here, according to the guide bush 10, the replacement frequency of the inner cylinder structure including the inner cylinder piece member 20 can be reduced by improving the wear resistance of the bar supporting surface 18. Next, with reference to FIG. 5, the configuration of a main part of an automatic lathe 50 provided with the guide bush 10 having the above configuration incorporated therein will be described. The guide bush 10 is moved through the sleeve member 52, the bearing device 54, and the flange member 56 near the machining position by the tool 58 set on the lathe base, and It is installed rotatably on column 60.

The guide bush 10 is accommodated in the front end (left end in the figure) area of the sleeve member 52 so as to be movable in the axial direction and not to rotate relatively. At the front end of the inner peripheral surface of the sleeve member 52, a plurality of pressure receiving surfaces 28 provided on the outer peripheral surface of the rod supporting portion 14 of the guide bush 10 28 2 is formed. In the rear end (right end in the figure) area of the sleeve member 52, an adjustment nut having a female thread to be screwed into the male thread 12c (Fig. 1A) provided on the base 12 of the guide bush 10 is provided. 6 and 4 are stored rotatably fixed in the axial direction. As a result, when the adjusting nut 64 rotates, the guide bush 10 moves in the axial direction within the sleeve member 52. Move in the direction.

A driven gear 68 is attached to the rear end region of the outer peripheral surface of the sleeve member 52 via a key 66. The driven gear 68 is connected to a guide bush drive source (not shown) via a power transmission mechanism (not shown), and has the same rotation speed as the main shaft 70 installed behind the column 60 by the guide bush drive source. It is driven to rotate at a rotation speed of. As a result, the driven gear 68, the adjusting nut 64, the sleeve member 52 and the guide bush 10 rotate integrally at the same rotation speed as the main shaft 70 inside the flange member 56. I do.

The flange member 56 is fixed to the column 60 by, for example, a bolt 72. Thus, the guide bush 10, the sleeving member 52, the flange member 56, the adjustment nut 64 and the driven gear 68 are formed as a rotary guide bush device that has been assembled in advance, and the automatic lathe 50 is used. It can be mounted in place on column 60. When the guide bush 10 is used as a fixed type guide bush device, the bearing device 54, the driven gear 68, the guide bush drive source and the like are omitted.

The spindle 70 holds a bar W to be turned and is driven to rotate by a spindle drive source (not shown). The main shaft 70 is installed movably in the axial direction behind the column 60 so that the rotation axis of the guide bush 10 and the rotation axis of the main shaft 70 coincide with each other. In the front end region of the main shaft 70, an openable / closable chuck 74 that can hold the bar W is accommodated. The chuck 74 is a so-called collet chuck having a slit at the tip. When an external force, that is, a pressing force is applied to the slit at a radially inward direction, the bar gripping hole 76 at the tip is formed. As the diameter is reduced, the check 74 is closed, and the bar W is firmly fixedly held. When the radial external force to the slit is released, the slit is restored and the bar gripping holes 7.6 expand, the chuck 74 opens, and the bar W is released. A hollow cylindrical operating member 78 is further housed in the main shaft 70 so as to be movable in the axial direction. The actuating member 78 accommodates the chuck 74 in its front end area, and is moved axially forward (to the left in the drawing) by a chuck driving source (not shown), so that the chuck 74 is radially inserted into the slit of the chuck 74. Apply inward pressing force to close check 74. When the operating member 78 is moved rearward in the axial direction (rightward in the figure) from this state, the chuck 74 is opened. The configuration of the main shaft 70 is not limited to the above. For example, as a mechanism for opening and closing the chuck, an operating member connected to the rear end of the chuck is moved axially rearward together with the chuck to apply a pressing force radially inward to the slit portion of the chuck. A configuration can also be employed.

In the automatic lathe 50 having the above configuration, when performing the machining work on the bar W, first, the outer cylindrical portion 16 of the guide bush 10 must correspond to the outer diameter of the bar W to be machined. An inner cylinder structure having a nominal inner diameter and an elastic intermediate cylinder 36 of an appropriate size are selected and attached, and attached to a sleeve member 52 mounted on a column 60. Next, the rod W gripped by the main shaft 70 is moved in the axial direction of the main shaft 70 without applying an external force inward in the radial direction to the outer cylinder portion 16, and the base of the guide bush 10 is moved. Insert it into the bar support 16 through the rear end opening. From this state, turn the adjustment nut 64 to move the guide push 10 backward in the axial direction, and to change the pressure receiving surface 28 a of the outer cylinder 16 to the pressure load surface 6 of the sleeve member 52. Press on 2. As a result, the three vertical split pieces 24 (FIG. 1B) of the outer cylinder part 16 are elastically deformed, and the three of the three pieces are elastically deformed by the elastic intermediate cylinder 36 and the elastic coupling element 34. By displacing the cylindrical piece member 20 radially inward, a desired minute gap on the order of μm is formed between the rod supporting surface 18 and the outer peripheral surface of the rod W. After adjusting the inner diameter of the rod supporting surface 18 of the guide bush 10 in this way, the guide bush 10 Turning is performed by, for example, a tool 58 while centering and supporting the vicinity of the processed portion of the bar W.

By the way, in the guide bush 10 described above, when the outer diameter of the bar is locally increased while the bar is fed in the axial direction, the arc-shaped wall portions 40 of the elastic intermediate cylinders 3.6 are formed. As a result, the plurality of inner cylinder piece members 20 are displaced radially outward by being compressed and elastically deformed between the outer cylinder portion 16 and each inner cylinder piece member 20, and The inner diameter of the material support surface 18 passively expands in accordance with the outer diameter of the bar. By utilizing such an action of the elastic intermediate cylinder 36, when adjusting the inner diameter of the rod supporting surface 18 described above, a minute micrometer of the order of μm is formed between the rod supporting surface 18 and the outer peripheral surface of the rod. Even if a gap is not intentionally formed, the bar can be centered and supported so that it can be fed in the axial direction simply by keeping the bar supporting surface 18 in contact with the outer peripheral surface of the bar.

From such a viewpoint, the guide bush according to the present invention can omit the mechanism for adjusting the inner diameter of the rod supporting surface. 6A and 6B show a guide bush 80 according to a second embodiment of the present invention having such a simplified configuration. Since the guide bush 80 has substantially the same configuration as the guide bush 10 described above except for the configuration of the outer cylindrical portion of the bar supporting portion, the corresponding components are denoted by the same reference numerals. The description is omitted.

The rod support portion 82 of the guide bush 80 includes an outer cylinder portion 84 integrally connected to the base portion 12 and a plurality (three) of inner cylinders installed inside the outer cylinder portion 84. A piece member 20 and an elastic member 22 for elastically holding the inner cylinder piece member 20 at a position where the bar support surface 18 is formed inside the outer cylinder portion 84 are provided. The bar support portion 82 has a center axis 82a that matches the center axis of the bar to be supported, and supports and centers the bar. As shown in FIGS. 7A and 7B, the outer cylindrical portion 84 It has a configuration in which the slit 26 in the outer cylindrical portion 16 of the brush 10 is omitted, and has a cylindrical shape that defines a central axis that matches the central axis 82 a of the bar support portion 82. It has an inner peripheral surface 84a. Therefore, the outer cylinder portion 84 cannot be substantially elastically deformed in the radial direction, and the inner diameter of the inner peripheral surface 84a cannot be changed.

The elastic intermediate cylinder 36 constituting the elastic member 22 has an outer surface 36a (FIG. 4A) abutting against an inner peripheral surface 84a of the outer cylinder portion 84 and an inner surface 36b. (FIG. 4A) is brought into contact with the outer surface 20a of the three inner cylinder piece members 20 and is disposed between the outer cylinder portion 84 and the inner cylinder piece members 20. The inner cylinder piece member 20 is supported from the outside. In the bar supporting portion 82 having such a configuration, the inner diameter of the bar supporting surface 18 formed by the three inner cylinder piece members 20 cannot be positively adjusted. On the other hand, when an external force is applied to the bar support surface 18 in the radially outward direction, each of the arc-shaped wall portions 40 of the elastic intermediate cylinder 36 (FIG. 4B) As such, by being compressed and elastically deformed between the outer cylinder portion 84 and each inner cylinder piece member 20, the inner cylinder piece members 20 are displaced radially outward, The inner diameter of the bar supporting surface 18 can be passively enlarged.

Accordingly, when the guide bush 80 having the above configuration is mounted on the automatic lathe 50 described above, the guide bush 80 has a rod W having an outer diameter corresponding to the inner diameter of the rod supporting surface 18, and With the surface 18 in contact with the outer peripheral surface of the bar, it can be centered and supported so that it can be axially fed. Here, even if a drawn material having low external dimensional accuracy is used as it is as the bar W, the bar support surface 18 is within the elastically deformable range of each arc-shaped wall portion 40 of the elastic intermediate cylinder 36. It is possible to passively enlarge and reduce the inner diameter of the rod to center and support the rod W so that it can be fed in the axial direction.

In the guide bushes 10 and 80 described above, the bar support portions 14 and 8 2 A plurality of inner cylinder piece members 20 installed in the first housing are connected to each other via an elastic connection element 34 so as to be relatively displaceable. However, the guide bush according to the present invention may also have a bar support portion in which a plurality of inner cylinder piece members are arranged inside the outer cylinder portion while being separated from each other. 8A and 8B show a guide bush 90 having such a configuration according to the third embodiment of the present invention. Since the guide bush 90 has substantially the same configuration as the guide bush 10 described above except for the configuration of the inner cylinder piece member and the elastic member of the bar support portion, the corresponding components have the same reference numerals. And the description is omitted.

The rod supporting portion 92 of the guide bush 90 is installed inside the outer cylindrical portion 16 which is integrally connected to the base portion 12 and which can be elastically deformed in the radial direction. Are formed from a hard material and cooperate with each other to form a plurality of (three) inner cylinder piece members 96 that form a substantially cylindrical bar support surface 94, and these inner cylinder piece members 96 And an elastic member 98 elastically held at a position where the bar support surface 94 is formed on the 內 side of the outer cylinder portion 16. The bar supporting portion 92 has a center axis 92 a that matches the center axis of the bar to be supported, and supports and centers the bar.

As shown in FIGS. 9A and 9B, each inner cylinder piece 96 of the guide bush 90 is attached to the inner surface 24 b of the corresponding vertical split piece 24 of the outer cylinder portion 16 (FIG. 2A). An outer surface 96a extending in an arc shape facing through a gap, an inner surface 96b extending in an arc on the opposite side of the outer surface 96a, and a flat surface between the outer surface 96a and the inner surface 96b. And a pair of extending side surfaces 96c. The three inner cylinder piece members 96 have a relative arrangement in which the respective inner surfaces 96 b are substantially positioned on a common cylindrical surface, and the respective side surfaces 96 c face each other with a gap therebetween. It is housed inside the outer cylinder part 16. In this state, the inner surfaces 96 b of the inner cylinder piece members 96 cooperate with each other to center and support the bar so that the bar can be axially fed. A holding surface 94 (having a central axis 94a) is formed.

Each inner cylinder piece member 96 has a flange portion 100 protruding radially outward, adjacent to one end surface 96 d in the axial direction. A flange portion 100 of each inner cylinder piece 96 has an engagement surface 100a extending in a tapered shape toward one end surface 96d in the axial direction, and a radially outer end surface thereof. A groove 100b extending in the axial direction is engraved. Further, each inner cylinder piece member 96 has an arc-shaped cross section at the boundary area between the inner surface 96 b and one end surface 96 d in the axial direction and the other end surface 96 e in the axial direction. Is formed.

As a hard material that can be suitably used for each inner cylinder piece member 96, engineering ceramics can be given. In this case, it is advantageous that at least the portion including the inner surface 96b forming the bar support surface 94 is made of zirconium ceramics having excellent wear resistance, impact strength, and surface smoothness. According to such a configuration, in particular, the durability of the bar supporting surface 94 can be significantly improved.

The elastic member 98 is interposed between the outer cylinder portion 16 and each of the three inner cylinder piece members 96 to elastically support the inner cylinder piece members 96 from outside. 36, and a pair of elastic support elements 104 engaged with the three inner cylinder piece members 96 to elastically support the inner cylinder piece members 96 from inside. The flexible intermediate cylinder 36 is brought into contact with the inner surface 24 b of the three vertical split pieces 24 of the outer cylinder portion 16 on the outer surface 36 a (FIG. 4A), and the inner surface 3 6 b (FIG. 4A), it comes into contact with the outer surfaces 96a of the three inner cylinder piece members 96. The elastic intermediate cylinder 36 applies a radially inward pressing force applied to each vertical split 24 of the outer cylindrical portion 16 to the corresponding inner cylinder located radially inward of each vertical split 24. It works so as to reliably transmit to the one-piece member 96. In addition, the elastic intermediate cylinder 36 supports a plurality of inner cylinder piece members 96 from the outside in the radial direction, thereby supporting the inner cylinder piece members 96 with cylindrical rod members. It is elastically held in the position where the surface 94 is formed. In addition, the elastic intermediate cylinder 36 receives adjacent pressures between the three vertically split pieces 24 of the outer cylinder part 16 and the three inner cylinder piece members 96 to form adjacent arc-shaped sections. Each arc-shaped wall portion 40 itself is flexible enough to be compressed and elastically deformed until the wall portions 40 (FIG. 4B) contact each other.

As shown in FIG. 10, each of the pair of elastic supporting elements 104 is formed of an annular spring formed by bending a spring wire into a C-ring shape. The elastic supporting elements 104 are respectively received in the pair of edge grooves 102 of the inner cylinder piece members 96 in a length region obtained by substantially dividing the entire length thereof into three equal parts. The one member 96 is elastically urged radially outward. As a result, the elastic support elements 104 cooperate with each other to move the three inner cylinder piece members 96 from the radially inner side to the position where the cylindrical bar support surface 94 is formed. Hold. Each elastic support element 104 does not have a function of mechanically interconnecting the inner cylinder piece members 96, but each has a radially inward surface on the outer surface 96a of the three inner cylinder piece members 96. When a pressing force is applied to the elastic support element 104, the elastic deformation is performed so as to reduce the diameter of the elastic support element 104 itself. Accordingly, the three inner cylinder piece members 96 are displaced radially inward until the opposing side surfaces 96c contact each other, and as a result, the inner cylinder piece members 96 are displaced. The inner diameter of the bar support surface 94 formed by the inner surface 96 b decreases. When the pressing force on the outer surface 96a of each inner cylinder piece member 96 is released, each inner cylinder piece member 96 returns to the initial position under the elastic restoring force of both elastic support elements 104. The inner diameter of the bar supporting surface 94 is restored.

The guide push 90 is manufactured by separately manufacturing the above-described various components and then assembling as follows. First, similarly to the above-described guide bush 10 assembling process, the bush body having the base portion 12 and the outer cylindrical portion 16 of the rod supporting portion 92 is integrally elastically attached. Assemble the intermediate cylinder 36. At this time, the detent 46 installed on one vertical split piece 24 of the outer cylinder part 16 is inserted into the groove 44 (Fig. 4B) of the elastic intermediate cylinder 36, so that the outer cylinder part 1 The rotation of the elastic intermediate cylinder 36 with respect to 6 is prevented. As shown in FIG. 11B, a second detent 48 protruding from the inner surface 24 b is provided on all the vertical pieces 24 of the outer cylindrical portion 16.

On the other hand, a pair of elastic support elements 104 are assembled as described above to three inner cylinder piece members 96 each molded from a hard material such as zirco-ceramics to form a substantially cylindrical inner cylinder. Create the structure. This inner cylinder structure is connected to the outer cylinder part 16 so that the outer surface 96 a of each inner cylinder piece 96 closely contacts the inner surface 36 b of the elastic intermediate cylinder 36 fitted in the outer cylinder part 16. The at least one of the intermediate cylinder 36 and the inner cylinder structure (mainly the elastic support element 104) is fitted inside the outer cylinder part 16 and the elastic intermediate cylinder 36 while elastically deforming at least one of them. At this time, the vertical split pieces 24 and the respective arc-shaped wall portions 40 of the elastic intermediate cylinder 36 and the internal cylinder piece members 96 of the internal cylinder structure are aligned with each other, and each vertical split piece 24 The second detent 48 projecting from the inner surface 24 b of the inner cylinder piece 96 is inserted into the groove 100 b formed in the flange portion 100 of the corresponding inner cylinder piece 96. As a result, the inner cylinder structure is positioned at a predetermined position inside the outer cylinder part 16 and the elastic intermediate cylinder 36 in a state where rotation of all the inner cylinder piece members 96 with respect to the outer cylinder part 16 is prevented. The outer cylinder part 16 and the elastic intermediate cylinder 36 and the inner cylinder structure (mainly the elastic support element 104) are held under the elastic restoring force generated by at least one of them. Preferably, in this state, each elastic support element 104 is fixedly received and held in the edge groove 102 of the three inner cylinder piece members 96 by its own elastic restoring force. .

When the guide bush 90 is properly assembled in this way, the three inner cylinder piece members 96 of the inner cylinder structure are formed by the bar support surface 94 formed by them. The center axis 94a of the rod support portion 92 is kept in a state of matching with the center axis 92a of the bar support portion 92. In addition, the engagement surface 100 a of the flange portion 100 formed on each inner cylinder piece member 96 of the inner cylinder structure is formed by a claw 30 formed on each vertically split piece 24 of the outer cylinder portion 16. The inner surface 96 a of the inner cylindrical piece 96 is closely contacted with the locking surface 30 a (FIG. 11A), and the axial end surface 96 d of the inner cylindrical piece 96 is open end surface 16 a of the outer cylindrical portion 16 (FIG. 11). A) is arranged on substantially the same plane adjacent to. In this state, the inner cylinder structure is prevented from unintentionally protruding from the predetermined position inside the outer cylinder portion 16 to the outside of the outer cylinder portion 16. In addition, the elastic intermediate cylinder 36 is disposed so as to be substantially shielded by the flange portion 100 of each of the inner cylinder piece members 96 at a position distant from the opening end face 16 a of the outer cylinder portion 16. As a result, the elastic intermediate cylinder 36 made of a relatively soft material is isolated from the chips scattered during the turning process, so that the damage is prevented.

In the guide bush 90, each vertical split piece 24 of the outer cylinder part 16, each inner cylinder piece member 96 of the inner cylinder structure, and each arc-shaped wall part 40 of the elastic intermediate cylinder 36 are arranged in the circumferential direction. They may be arranged offset from each other. Also, assuming that the outer cylinder part 16, the inner cylinder structure and the elastic intermediate cylinder 36 can generate the intended elastic deformation, the vertical split piece 24 of the outer cylinder part 16 and the inner cylinder structure The numbers of the inner cylinder piece member 96 and the arc-shaped wall portion 40 of the elastic intermediate cylinder 36 may be different from each other, and may be various numbers other than three.

The guide bush 90 having the above configuration operates in the same manner as the guide bush 10 described above. That is, when an external force is applied radially inward to the three vertical split pieces 24 of the outer cylindrical portion 16, the vertical split pieces 24 are elastically deformed, and at the same time, the inner surface of each vertical split piece 24 is formed. The outer surface 36 a of the elastic intermediate cylinder 36 in contact with 24 b is loaded with an external force radially inward from each of the vertical split pieces 24, thereby causing the elastic intermediate cylinder 36 to be elastic as described above. Deformed fruit The qualitative inner diameter dimension is reduced. Accordingly, an external force is applied radially inward from the elastic intermediate cylinder 36 to the outer surfaces 96 a of the three inner cylinder piece members 96 that are in contact with the inner surface 36 b of the elastic intermediate cylinder 36. As a result, as described above, under the elastic deformation of the pair of elastic support elements 104, the inner diameter of the bar support surface 94 formed by the inner surfaces 96b of the inner tubular piece members 96 decreases. From this state, if the radial external force on the vertical split pieces 24 of the outer cylinder part 16 is reduced, the vertical split pieces 24 restore elasticity, and accordingly the elastic intermediate cylinder 36 and both elastic supports Element 104 recovers elastically, and the inner diameter of bar support surface 94 increases (restores). While the inner diameter of the bar supporting surface 94 decreases and increases, the three inner cylinder piece members 96 move the center axis 94 a of the bar supporting surface 94 to the bar supporting portion 92. Displaces in the radial direction while maintaining the state of alignment with the central axis 92a of As described above, in the guide push 90, the external force, that is, the pressing force applied radially inward to the bar support portion 92 is adjusted, whereby the rod formed by the three inner cylinder piece members 96 is adjusted. The inner diameter of the material support surface 94 can be adjusted.

In the guide bush 90, the inner diameter of the bar support surface 94 formed by the three inner cylinder piece members 96 is such that while the guide bush 90 is in a non-operating state, the rod material to be supported (processed) is It is set to be larger than the outside diameter of. Then, before the actual machining operation in which the guide bush 90 is put into the working state, the target bar is inserted into the bar support portion 92, and the inner diameter of the bar support surface 94 is changed as described above. By making fine adjustments in accordance with the outer diameter of the bar, a desired fine gap of the order of μm is obtained between the bar support surface 94 and the outer peripheral surface of the bar. The guide bush 90 can center and support the bar so that it can be fed in the axial direction by securing such a fine gap in the operating state.

Here, when a “pulled material” with low external dimensional accuracy that has been drawn to a specified diameter and has low external dimensional accuracy is used as it is as a bar material to be supported (processed), The fine gap described above is formed at the minimum outer diameter part of the bar.

Finely adjust the inner diameter of the bar support surface 94. In this state of operation, while the rod supported by the guide bush 90 is fed in the axial direction, the friction between the rod supporting surface 94 and the outer peripheral surface of the rod increases due to the increase in the outer diameter of the rod. Since the vertical split pieces 24 of the outer cylinder part 16 are in a state where they cannot be displaced radially outward, each arc-shaped wall part 40 of the elastic intermediate cylinder 36 has the outer cylinder part 16 and the inner cylinder structure. When the pressure is applied between them, they are elastically deformed as described above. As a result, each inner cylinder piece member 96 is displaced radially outward, and the inner diameter of the rod supporting surface 94 is passively enlarged in accordance with the outer diameter of the rod. In this way, the guide bush 90 can center and support a rod made of a drawn material so that it can be fed in the axial direction. In addition, at this time, since each inner cylinder piece member 96 is formed of a hard material, the wear resistance of the rod supporting surface 94 is significantly improved, and each inner cylinder piece member caused by friction with the rod material is formed. The progress of the wear of 96 can be suppressed as much as possible.

The elastic support element 104 incorporated in the guide bush 90 can be additionally incorporated in the aforementioned guide bush 10 having the elastic connection element 34. According to such a configuration, since the elastic action of the elastic member 22 in the guide bush 10 can be enhanced, the responsiveness of the radial displacement operation of the inner cylinder piece member 20 can be improved, and the rod support portion 1 can be improved. 4 to obtain more accurate centering support characteristics. Further, when the plurality of inner cylinder piece members 20 are combined into a cylindrical shape using the elastic connecting element 34 made of a liquid gasket, even if the positional accuracy of each inner cylinder piece member 20 is somewhat low, the combination is performed. However, by the support operation of the elastic support elements 104, the positional accuracy of each inner cylinder piece member 20 can be obtained as a result. This simplifies the manufacturing process of the guide push 10 and reduces the work cost when the inner cylinder piece 20 is replaced.

As is clear from the above description, according to the present invention, an automatic lathe is installed. In the guide bush to be installed, the outer diameter of the bar to be machined is changed by providing the bar support of multi-layer structure. ゃ Not only can the wear of the bar support surface be quickly dealt with, but also the bar The wear resistance of the support surface can be significantly improved. Therefore, according to the present invention, the influence of the wear of the guide push, particularly the bar supporting surface, on the processing accuracy and the manufacturing cost of the product in the automatic lathe can be reduced as much as possible, and the bar made of the drawn material is used. In such a case, it becomes possible to produce high-quality products.

As described above, some preferred embodiments according to the present invention have been described. However, the present invention is not limited to these embodiments, and various modifications and changes can be made within the disclosure of the claims.

Claims

The scope of the claims

1. In a guide push including a hollow cylindrical base portion and a hollow cylindrical bar support portion provided adjacent to one end in the axial direction of the base portion, the rod support portion includes:

An outer cylinder part integrally connected to the base,

A plurality of inner cylinder piece members installed inside the outer cylinder portion, each being formed of a hard material, and forming a cylindrical bar support surface in cooperation with each other;

A guide bush comprising: an elastic member that elastically holds the plurality of inner cylinder piece members at a position forming the bar support surface inside the outer cylinder part.

2. The guide bush according to claim 1, wherein the elastic member includes an elastic connecting element interposed between the adjacent inner cylinder piece members to elastically connect the inner cylinder piece members to each other.

3. The guide bush according to claim 2, wherein the elastic connecting element is formed from a liquid gasket.

4. The elastic member includes an elastic intermediate cylinder interposed between the outer cylinder portion and each of the plurality of inner cylinder piece members to elastically support the inner cylinder piece members from the outside. Guide bush described in.

5. The guide bush according to claim 4, wherein the elastic intermediate cylinder is formed of a soft material that can be compressed and elastically deformed between the outer cylinder portion and the plurality of inner cylinder pieces.

6. The guide bush according to claim 1, wherein the elastic member includes an elastic support element that engages with the plurality of inner cylinder piece members and elastically supports the inner cylinder piece members from the inside.

7. The elastic support element moves the plurality of inner cylinder pieces outward in the radial direction. Guy Dobu' shoe according to claim 6, which is formed from a spring that resiliently biases ₀

8. The guide bush according to claim 1, wherein in each of the plurality of inner cylinder piece members, at least a portion forming the bar support surface is made of ceramics.

9. The outer cylinder portion of the bar support portion can be elastically deformed in the radial direction, and the inner diameter dimension of the bar support surface formed by the plurality of inner cylinder piece members with the elastic deformation of the outer cylinder portion. The guide bush according to claim 1, wherein

10. An automatic lathe having the guide push according to any one of claims 1 to 9 installed in the vicinity of a bar material processing operation position.