JP2022160131A - Machine tool - Google Patents

Abstract

To provide a machine tool capable of improving working properties for attaching an ejector pin according to a shape of workpiece, to a front end of a pressing rod.SOLUTION: A machine tool (1) comprises: a main shaft (21); a grip mechanism 22; a pressing rod 23; an ejector pin 30; a holding member 24; and an extrusion mechanism 25. The holding member 24 is arranged at outside of the pressing rod 23 with a spindle center line (AX2) as a center, and holds the pressing rod 23 to a shaft center position with the spindle center line (AX2). The extrusion mechanism (25) applies force in an advance direction D1 to the pressing rod 23 which passed through the holding member 24, for extruding workpiece W1 released from the grip mechanism 22 by the ejector pin 30. An aggregate 31 including: an ejector pin main body 40 capable of being inserted into the holding member 24, the ejector pin main body 40 capable of being fitted to the front end 23a of the pressing rod 23 in a detachable state; and a contact member 45 capable of being detachably fitted to the front end 40a of the ejector pin main body 40, is fitted, as the ejector pin 30, to the front end 23a of the pressing rod 23.SELECTED DRAWING: Figure 7

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a machine tool having a work discharge device on its spindle.

2. Description of the Related Art As a machine tool, a lathe is known in which a workpiece, which has been front-machined by a front headstock and a tool post, is back-machined by a back headstock and a tool post. The back headstock is provided with a work ejection device for ejecting the back-machined workpiece.

Patent Literature 1 discloses an automatic lathe having a work discharge device on the back spindle. The automatic lathe includes a gripping mechanism that releasably grips a workpiece at the front end of the back spindle. The gripping mechanism includes a tip-side collet sleeve (chuck sleeve) and a rear-end collet sleeve (push sleeve) inserted into the back spindle, a collet disposed inside the tip-side collet sleeve, the rear end of the collet and the tip-side collet. a compression coil spring between the rear end of the sleeve, a cap attached to the front end of the rear main shaft, a rotating member (claw member) having an engaging portion engaged with the rear end of the rear collet sleeve, An action sleeve (shifter) that rotates the rotating member by moving in the direction of the center line of the main shaft is provided. The gripping mechanism grips the workpiece with the collet by advancing the distal collet sleeve, and releases the workpiece from the collet by retracting the distal collet sleeve. A push rod to which an ejector pin is attached is inserted into the back spindle. The push rod is a rotating body that rotates with the back main shaft. A substantially cylindrical front side holding member and an annular rear side holding member are provided inside the back main shaft and are arranged outside the push bar to hold the push bar at the axial position. The front side holding member is arranged inside the distal side collet sleeve and the rear side collet sleeve. The rear holding member is attached inside the rear main shaft. The automatic lathe has an extrusion mechanism that applies force in the forward direction to a push rod passing through the front side holding member and the rear side holding member, and pushes out the workpiece released from the collet with an ejector pin.

The collet, tip side collet sleeve, and ejector pin are replaced according to the size and shape of the workpiece. If the ejector pin can be passed through the substantially cylindrical front side holding member that holds the push rod, the ejector pin is attached to the front end of the push rod that is not inserted into the back spindle, and the back spindle where the rear side holding member exists. After inserting the ejector pin and push rod from the front end, the distal collet sleeve with the front retaining member attached can be inserted from the front end of the back spindle into the back spindle.

Japanese Patent Application Laid-Open No. 2008-30140

For example, if the workpiece has a through hole that runs along the center line of the spindle, the outer diameter of the front end of the ejector pin must be larger than the inner diameter of the hole in the workpiece in order to eject the workpiece from the back spindle. . If the outer diameter of the front end of the ejector pin needs to be larger than the inner diameter of the substantially cylindrical front side holding member in order to push out a workpiece having a through hole, the ejector pin and push rod are inserted into the back spindle from the front end of the back spindle. After that, the distal side collet sleeve attached with the front side holding member cannot be inserted into the rear main shaft from the front end of the rear main shaft. In order to maximize the outer diameter of the front end of the ejector pin, the push rod is designed to be as thick as possible and the inner diameter of the front side holding member is designed to be as large as possible.
Here, only the cap and collet are removed from the back spindle, and with only the push rod inserted into the back spindle, the tip side collet sleeve and the cylindrical front side holding member are inserted into the back spindle from the front end of the back spindle, and the front side holding member is inserted. Assume that an ejector pin is attached to the front end of the pushed rod. In this case, since the front end of the push rod is inside the tip side collet sleeve even when the push rod is most advanced, the operator needs to attach the ejector pin to the front end of the push rod inside the tip side collet sleeve. be. In this case, workability for attaching the ejector pin is not good.
On the other hand, it is necessary to push out workpieces of various sizes, shapes, etc. from the main shaft with an ejector pin.

The above-described problems also exist in lathes that push out a workpiece from the front spindle and machine tools other than lathes.
The present invention discloses a machine tool capable of improving the workability of attaching an ejector pin suitable for the shape of a work to the front end of a push rod.

The machine tool of the present invention is
a spindle rotatable about the spindle centerline;
a gripping mechanism for releasably gripping a workpiece at the front end of the spindle;
a push rod inserted into the main shaft and movable in a forward direction for pushing out the work and a backward direction opposite to the forward direction;
an ejector pin replaceably attached to the forward end of the pushrod;
a holding member disposed outside the push rod around the center line of the main shaft and holding the push rod at an axial position around the center line of the main shaft;
a pushing mechanism for pushing out the workpiece released from the gripping mechanism with the ejector pin by applying force in the forward direction to the push rod passing through the holding member;
an ejector pin body that can be passed through the holding member and that is detachably attached to the front end of the push rod; and a backing member that is detachably attached to the front end of the ejector pin body. is attached to the front end of the push rod as the ejector pin.

According to the present invention, it is possible to provide a machine tool that improves the workability of attaching an ejector pin suitable for the shape of a workpiece to the front end of a push rod.

FIG. 4 is a front view schematically showing an example of a lathe in which the door of the processing chamber is closed; FIG. 4 is a front view schematically showing an example of the lathe with the door of the processing chamber open. FIG. 4 is a diagram schematically showing an example of a lathe door device; FIG. 4 is a perspective view schematically showing an example of a working portion of a lathe; It is a block diagram which shows typically the structural example of the electric circuit of a lathe. FIG. 4 is a vertical cross-sectional view schematically showing an example of a back headstock provided with a work discharging device; FIG. 4 is a vertical cross-sectional view schematically exemplifying a main part of a back headstock provided with a work discharging device; Figures 4A and 4B schematically show examples of various ejector pins that can be attached to the front end of the pushrod; FIG. 3 is a diagram schematically illustrating an inner diameter Dh of a holding member of a push rod, an outer diameter Dp of a contact member, an outer diameter Dw of a work, and an inner diameter dw of a work hole; FIG. 5 is a diagram schematically illustrating a state in which a contact member is attached to an ejector pin main body with the cap and collet removed from the back main shaft; FIG. 4 is a perspective view schematically showing an example of a tool post table and a sleeve holder; FIG. 5 is a diagram schematically illustrating sizes of sleeve holders compared with reference examples. FIG. 4 is a vertical cross-sectional view schematically illustrating the inside of a sleeve holder compared with a reference example; FIG. 14 is a cross-sectional view of the sleeve holder at position A1-A1 in FIG. 13; It is a figure which illustrates typically the cover structure compared with a reference example. FIG. 2 is a perspective view schematically showing an example of a lathe in which an exterior cover is removed from an exterior member; 1 is a perspective view schematically showing an example of a lathe with an exterior cover attached to an exterior member; FIG. FIG. 4 is a diagram schematically illustrating an inner diameter Dh of a holding member of a push rod, an outer diameter De of an integrated ejector pin, an outer diameter Dw of a work, and an inner diameter dw of a work hole; FIG. 10 is a diagram schematically showing how an integrated ejector pin is attached to a push rod with the cap and collet removed from the back spindle in a comparative example.

Embodiments of the present invention will be described below. Of course, the following embodiments are merely illustrative of the present invention, and not all features shown in the embodiments are essential to the solution of the invention.

(1) Overview of technology included in the present invention:
First, an overview of the technology involved in the present invention will be described with reference to the examples shown in FIGS. 1-19. It should be noted that the figures of the present application are diagrams schematically showing examples, and the magnification in each direction shown in these figures may differ, and each figure may not match. Of course, each element of the present technology is not limited to specific examples indicated by reference numerals.

[Aspect 1]
As illustrated in FIGS. 6 and 7 , a machine tool (for example, a lathe 1) according to one aspect of the present technology includes a spindle (for example, a back spindle 21), a gripping mechanism 22, a push rod 23, an ejector pin 30, a holding member 24 , and an extrusion mechanism (for example, a coil spring 25). The main shaft (21) is rotatable around a main shaft centerline (for example, main shaft centerline AX2). The gripping mechanism 22 releasably grips the workpiece W1 at the front end 21a of the main shaft (21). The push rod 23 is inserted into the main shaft (21) and is movable in a forward direction D1 for pushing out the workpiece W1 and a backward direction D2 opposite to the forward direction D1. The ejector pin 30 is replaceably attached to the front end 23 a of the push rod 23 . The holding member 24 is arranged outside the push rod 23 with the main shaft center line (AX2) as the center, and is positioned at an axial center position with the main shaft center line (AX2) as the center (for example, positions shown in FIGS. 6 and 7). holds the push rod 23 in the position. The push-out mechanism (25) applies force in the forward direction D1 to the push rod 23 passing through the holding member 24, thereby ejecting the work W1 released from the gripping mechanism 22 with the ejector pin 30. Push out. The front end 23a of the push rod 23 is provided with an ejector pin body 40 that can be passed through the holding member 24 and is detachably attached to the front end 23a of the push rod 23, and the ejector. A contact member 45 detachably attached to the front end 40 a of the pin body 40 is attached as the ejector pin 30 .

In the above mode 1, since the ejector pin body 40 can be passed through the holding member 24 of the push rod 23, the ejector pin body 40 is attached to the front end 23a of the push rod 23 that is not inserted into the main shaft (21). After inserting the ejector pin body 40 and the push rod 23 into (21) from the front end of the main shaft (21), the holding member 24 etc. can be inserted into the main shaft (21) from the front end of the main shaft (21). For example, when the gripping mechanism 22 has a chuck sleeve 209 as shown in FIGS. A chuck sleeve 209 with a holding member 24 attached can be inserted into the main shaft (21) from the front end of the main shaft (21). Since the front end 40a of the ejector pin body 40 is on the front side of the front end 23a of the push rod 23, the contact member 45 can be easily attached to the front end 40a of the ejector pin body 40 while the push rod 23 is advanced. 6 and 7, the front end 40a of the ejector pin body 40 is located forward of the chuck sleeve 209, so the abutment member 45 is placed against the front end 40a of the ejector pin body 40 while the push rod 23 is moving forward. Easy to install. In particular, even if the abutment member 45 cannot be passed through the holding member 24 of the push rod 23, after the ejector pin body 40 and the push rod 23 are passed through the holding member 24, the abutment member 45 is attached to the front end 40a of the ejector pin body 40. By attaching it, the contact member 45 that cannot be passed through the holding member 24 can be arranged on the front side of the holding member 24 . Therefore, Aspect 1 can provide a machine tool that improves the workability of attaching an ejector pin suitable for the shape of a workpiece to the front end of the push rod. As a result, for example, the push rod, which is a rotating body, can be designed thinner than before, the vibration of the rotating body can be reduced by reducing the weight, and the manufacturing cost of the push rod can be reduced. Moreover, even if the front end of the ejector pin wears out, only the contact member needs to be replaced, so the running cost can be reduced.

Here, the principal axis includes a back principal axis, a front principal axis, and the like.
Work also includes a work that has been machined, ie, a product.
A gripping tool that grips a workpiece in the gripping mechanism includes a collet, a claw, and the like.
The pushing mechanism includes a spring such as a compression coil spring, a cylinder such as an air cylinder or an electric cylinder, and the like.
The ejector pin body may be divided into two or more. The contact member may also be divided into two or more.
In addition, the additional remark mentioned above is applied also to the following aspects.

[Aspect 2]
As illustrated in FIG. 8 and the like, the front end 23a of the push rod 23 includes the assembly 31 and a portion (such as a contact portion 34) that contacts the work W1 from a portion (such as a male screw portion 33) attached to the push rod 23. ) may be interchangeably attached as the ejector pin 30 . For example, when the workpiece W1 is thin, it is necessary to reduce the inner diameter of the gripping tool (for example, the collet 213) that grips the workpiece W1. If the integrated ejector pin 32 can be passed through the holding member 24 of the push rod 23, the integrated ejector pin 32 is attached to the front end 23a of the push rod 23 when it is not inserted into the main shaft (21). After inserting the integrated ejector pin 32 and push rod 23 from the front end of the main shaft (21), the holding member 24 and the like can be inserted into the main shaft (21) from the front end of the main shaft (21). In this case, the operation of attaching the contact member 45 to the front end 40a of the ejector pin main body 40 becomes unnecessary. For example, when the gripping mechanism 22 has a chuck sleeve 209 as shown in FIGS. , the chuck sleeve 209 to which the holding member 24 is attached can be inserted into the main shaft (21) from the front end of the main shaft (21). In addition to the assembly 31 including the ejector pin main body 40 and the backing member 45, the integrated ejector pin 32 can also be attached to the front end 23a of the push rod 23. Therefore, in this embodiment, an ejector pin suitable for the shape of the workpiece can be attached to the push rod. It is possible to provide a machine tool that further improves the workability of attaching to the front end of the.

(2) Specific example of machine tool configuration:
1 to 5 schematically illustrate a lathe 1 as an example of a machine tool. FIG. 1 is a front view schematically illustrating the lathe 1 with the door 3 of the processing chamber C1 closed. FIG. 2 is a front view schematically showing the lathe 1 with the door 3 of the processing chamber C1 open. 1 and 2, the ranges of the machining chamber C1 and the headstock chamber C2 are indicated by dashed lines. FIG. 3 is a view schematically illustrating the door device 300 of the lathe 1, and is a view of the lathe 1 viewed from the right, omitting illustration of a part of the exterior 2 covering the processing chamber C1. FIG. 4 is a perspective view schematically exemplifying the processing portion of the lathe 1. As shown in FIG. A tool post table 51 schematically shown in FIG. 4 omits the extending portion 51e and the guide mounting portion 51g illustrated in FIG. FIG. 5 is a block diagram schematically illustrating the configuration of the electric circuit of the lathe 1. As shown in FIG.

1 to 4, etc., the code D81 indicates the upward direction, the code D82 indicates the downward direction, the code D83 indicates the left direction, the code D84 indicates the right direction, the code D85 indicates the front direction, and the code D86 indicates the direction. It shows the depth direction. These directions are based on the viewing direction of the lathe 1 shown in FIG. Symbols X1, Y1, Z1, X2 and Z2 indicate control axes.
It should be noted that the drawings referred to in this specification merely show examples for explaining the present technology and are not intended to limit the present technology. The description of the positional relationship of each part is merely an example. Therefore, reversing left and right, reversing the direction of rotation, etc. are also included in the present technology. Identicalness in direction, position, etc. is not limited to strict matching, and includes deviation from strict matching due to errors.

The lathe 1 shown in FIGS. 1 to 5 is an NC lathe provided with an NC (Numerical Control) device 70 for numerically controlling machining of a work W1 in a machining chamber C1. As shown in FIGS. 1 and 2, the front face of the lathe 1 is provided with an operating section 80 having an input section 81 and a display section 82, and an openable and closable door 3 on the right side of the operating section 80. FIG. An exterior 2 covering the processing chamber C1 has an opening 2op that matches the shape of the door 3. As shown in FIG. Inside the lathe 1, there are provided a machining chamber C1 which is opened when the door 3 is opened, and a headstock chamber C2 on the left of the machining chamber C1. The door 3 opens and closes while being guided by the door rail 4 shown in FIG. Details of the door device 300 including the door 3 and the door rail 4 will be described later. FIG. 2 shows the coolant supply unit 5 that supplies coolant to the workpiece W1 being machined. A liquid such as oil can be used as the coolant.

The lathe 1, as shown in FIG. 4, is a moving spindle type lathe including a front headstock 10, a back headstock 20, a gang tool rest 50, and the like.
The front headstock 10 incorporates a front main spindle 11 rotatable about the main spindle centerline AX1 and is movable in the Z1-axis direction. The Z1-axis direction shown in FIG. 4 is the horizontal direction along the spindle centerline AX1. The front spindle 11 is also called a main spindle. The front main spindle 11 has a collet 12 as a gripping tool at its front end, releasably grips the workpiece W1, and is rotatable together with the workpiece W1 about the spindle center line AX1. When the work W1 before processing is, for example, a cylindrical (rod-shaped) elongated material, the work W1 may be supplied to the collet 12 from the rear end of the front main shaft 11 . In this case, a guide bush 15 that supports the workpiece W1 so as to be slidable in the Z1-axis direction may be arranged on the front side of the front main spindle 11 . Of course, the present technology can be applied even if the lathe 1 does not have the guide bush 15 .

A work W1 after front machining is transferred from the front main spindle 11 to the back main spindle 21. - 特許庁The back headstock 20 incorporates a back spindle 21 rotatable around the spindle centerline AX2, and is movable in the Z2-axis direction and the X2-axis direction. The Z2-axis direction shown in FIG. 4 is the horizontal direction along the spindle centerline AX2. The X2-axis direction shown in FIG. 4 is a horizontal direction orthogonal to the spindle centerline AX2. When the main spindle centerline AX2 coincides with the main spindle centerline AX1, the back main spindle 21 is positioned to face the front main spindle 11. As shown in FIG. The back main shaft 21 is also called a sub-spindle or a counter main shaft. The back spindle 21 is provided with a collet 213 as a gripping tool at the front end, releasably grips the workpiece W1, and is rotatable about the spindle centerline AX2 together with the workpiece W1 after front machining. The work W1 after the front face machining becomes a product by the back face machining, and is pushed out from the back main spindle 21 and discharged by the work discharge device 100 illustrated in FIG. 6 and the like. The back spindle 21 is an example of a spindle into which the work discharge device 100 is incorporated.

The comb-shaped tool post 50 has a metal tool post table 51 on which a plurality of tools T1 for machining the work W1 are attached, and is movable in the X1-axis direction and the Y1-axis direction. The X1-axis direction shown in FIG. 4 is a horizontal direction orthogonal to the spindle centerlines AX1 and AX2. The Y1-axis direction shown in FIG. 4 is a vertical direction orthogonal to the spindle centerlines AX1 and AX2.
It should be noted that "perpendicular" is not limited to strict 90 degrees, and includes deviations from strict 90 degrees due to errors. In addition, the X1 axis and the Y1 axis do not have to be orthogonal as long as they intersect, the Y1 axis and the Z1 axis do not have to be orthogonal as long as they intersect, and the Z1 axis and the X1 axis do not have to be orthogonal. It does not have to be orthogonal if it is. Furthermore, the X2-axis and the Y1-axis may not be orthogonal as long as they intersect, the Y1-axis and Z2-axis may not be orthogonal as long as they intersect, and the Z2-axis and X2-axis may intersect. It does not have to be orthogonal if it is. The X2-axis direction may be a direction shifted from the X1-axis direction.

The tool rest table 51 has an opening OP1 penetrating in the Z1-axis direction, and allows the workpiece W1 to pass therethrough in the Z1-axis direction. The turret table 51 has an upper portion 51a in which a metal sleeve holder 60 is attached to a surface 51z facing the back headstock 20, a front vertical portion 51c in which a plurality of tools T1 projecting in the depth direction D86 are attached, It has a back side vertical portion 51d to which a plurality of tools T1 projecting in the front direction D85 are attached, and a bottom portion 51b connecting the bottom of the front side vertical portion 51c and the bottom of the back side vertical portion 51d. The comb-shaped tool post 50 is a tool post configured so that a plurality of tools T1 surround the work W1. The sleeve holder 60 includes an attachment portion 61 to the tool post table 51 , a holding portion 62 for the tool unit U<b>1 , and a communication portion 63 connecting the attachment portion 61 to the holding portion 62 . The plurality of tools T1 include a cutting tool including a cut-off tool T2, a drill T3, a rotating tool T4, and the like. A plurality of tool units U1 are attached to the sleeve holder 60 attached to the upper portion 51a of the tool rest table 51. As shown in FIG. The tool unit U1 shown in FIG. 4 is a drill unit including a drill T3, but the tool unit U1 is not limited to a drill unit. Details of the sleeve holder 60 and the tool post table 51 will be described later. In the machining chamber C1, the comb-shaped tool post 50 performs front machining of the workpiece W1 held by the collet 12 of the front main spindle 11 with the tool T1, and is held by the collet 12 of the front main spindle 11 and the collet 213 of the back main spindle 21. The work W1 is cut off by the cut-off tool T2, and the work W1 held by the collet 213 of the back spindle 21 is cut off by the tool T1.

The lathe 1 may include a back machining tool post 59 for machining the back of the work W1 gripped by the collet 213 of the back spindle 21 . A plurality of tools T1 (for example, drills T3) arranged in the X2-axis direction are attached to the back surface machining tool post 59 shown in FIG. By moving the back surface headstock 20 in the X2-axis direction, the tool T1 used for back surface processing can be switched without moving the back surface machining tool post 59 . Furthermore, the lathe 1 may be provided with a tool post such as a turret tool post.

Movements of the front headstock 10, the back headstock 20, and the gang tool rest 50 are controlled by an NC device 70 shown in FIG. The NC device 70 shown in FIG. 5 includes a CPU (Central Processing Unit) 71 that is a processor, a ROM (Read Only Memory) 72 that is a semiconductor memory, a RAM (Random Access Memory) 73 that is a semiconductor memory, a clock circuit 74, an I/ F (interface) 75, and the like. In FIG. 5, an operation unit 80, a front headstock drive unit DR1, a front main spindle rotation drive unit DR2, a collet drive unit DR3, a gang tool post drive unit DR4, a rear headstock drive unit DR5, a back main spindle rotation drive unit DR6, a collet The I/Fs of the drive unit DR7, etc. are collectively indicated as I/F75. The ROM 72 is written with a control program PR1 for interpreting and executing the machining program PR2. The ROM 72 may be a rewritable semiconductor memory. The RAM 73 rewritably stores a machining program PR2 created by the operator. A machining program is also called an NC program. The CPU 71 uses the RAM 73 as a work area and executes the control program PR1 recorded in the ROM 72 to control the operation of each section. The operation unit 80 has an input unit 81 and a display unit 82 and functions as a user interface for the NC device 70 . The input unit 81 is composed of, for example, buttons and a touch panel for receiving operation input from an operator. The display unit 82 is configured by, for example, a display that displays the contents of various settings received from the operator and various information regarding the lathe 1 . The operator can store the machining program PR2 in the RAM 73 using the operation unit 80 or an external computer (not shown).

The front headstock drive unit DR1 moves the front headstock 10 in the Z1-axis direction according to a command from the NC unit 70 . The front main shaft rotation drive unit DR2 rotates the front main shaft 11 around the main shaft center line AX1 according to a command from the NC device 70 . Collet drive unit DR3 drives the gripping mechanism (including collet 12) of front spindle 11 according to a command from NC device 70. As shown in FIG. The gang tool post drive unit DR4 drives the gang tool post 50 in the X1-axis direction and the Y1-axis direction according to commands from the NC device 70 . The back headstock drive unit DR5 moves the back headstock 20 in the Z2-axis direction and the X2-axis direction according to a command from the NC device 70 . The back spindle rotation drive unit DR6 rotates the back spindle 21 around the spindle center line AX2 according to a command from the NC device 70 . The collet drive unit DR7 drives the gripping mechanism 22 (see FIG. 6) of the back main shaft 21 according to a command from the NC device 70. As shown in FIG.

(3) Specific example of workpiece discharging device:
As exemplified in FIGS. 6 and 7, the back spindle 21 incorporates a work discharge device 100 that pushes out and discharges the workpiece W1 after back machining, that is, the product from the back spindle 21 . FIG. 6 is a longitudinal sectional view schematically illustrating the back headstock 20 provided with the work discharge device 100. As shown in FIG. FIG. 7 is a schematic longitudinal sectional view enlarging the front side of the back headstock 20 shown in FIG.
In the work discharging device 100 shown in FIGS. 6 and 7, the forward direction D1 for pushing out the work W1 is the left direction D83, and the backward direction D2 opposite to the forward direction D1 is the right direction D84. In the description of the work discharging device 100, the side in the left direction D83 may be described as the front side, and the side in the right direction D84 may be described as the rear side.

The back headstock 20 shown in FIGS. 6 and 7 has a housing 201 in which the back spindle 21 is rotatably installed. Bearings 205 and 206 (for example, ball bearings) are provided between the housing 201, which is a non-rotating body, and the back main shaft 21, which is a rotating body. The back spindle 21 has a through hole 21h passing through along the spindle centerline AX2.
The back spindle 21 incorporates a gripping mechanism 22 that releasably grips the workpiece W1 at the front end portion 21a of the back spindle 21, and a workpiece discharge device 100. As shown in FIG. The gripping mechanism 22 includes a chuck sleeve 209, a push sleeve 211, a collet 213, a coil spring 215, a cap 216, a claw member 219, a shifter 221, a lever 223, an actuator 225, and the like. A collet drive unit DR7 shown in FIG. 5 is a drive unit that operates the collet 213 around the actuator 225 . The work ejection device 100 includes a push rod 23, an ejector pin 30, a substantially cylindrical holding member 24, an annular rear holding member 26, a coil spring 25, and the like. The holding member 24 is located on the front side of the rear holding member 26 and can also be called a front holding member. Coil spring 25 is an example of a pushing mechanism.

A chuck sleeve 209 and a push sleeve 211 are arranged in the through hole 21h of the back main shaft 21 so as to be movable in the forward direction D1 and the backward direction D2. The rear end of the chuck sleeve 209 abuts the front end of the push sleeve 211 . The chuck sleeve 209 and the push sleeve 211 have a cylindrical shape with a through hole penetrating along the spindle centerline AX2. be. A collet 213 and a coil spring 215 are arranged in the through hole of the chuck sleeve 209 . The inner surface of the chuck sleeve 209 is provided with a tapered portion 209a at the front end that matches the tapered portion 213b on the outer surface of the collet 213, and an engaging portion 209b that engages with the rear end of the coil spring 215 is provided near the rear end. is provided. A cap 216 that holds a collet 213 pressed by a coil spring 215 is attached to the front end portion 21 a of the back main shaft 21 .

The collet 213 has slots at a plurality of locations (eg, three locations) from the front end to the tapered portion 213b. When the tapered portion 213b of the collet 213 is pushed by the tapered portion 209a of the chuck sleeve 209, the collet 213 grips the workpiece W1. When the tapered portion 209a of the chuck sleeve 209 presses against the tapered portion 213b of the collet 213, the collet 213 releases the workpiece W1. A coil spring 215 arranged between the rear end of the collet 213 and the engaging portion 209b of the chuck sleeve 209 is a compression coil spring, which applies a force in the forward direction D1 to the collet 213 and causes the chuck sleeve 209 to move in the backward direction. Apply force to D2.

Claw members 219 are provided at a plurality of locations (for example, two locations) on the outer circumference of the back main shaft 21 , and a shifter 221 is provided on the front side of these claw members 219 . Each pawl member 219 is in contact with an engaging portion 219a against which the rear end of the substantially cylindrical push sleeve 211 abuts, and a tapered portion 221a on the outer surface of the shifter 221 in a slidable state. A contact portion 219b is provided. Each pawl member 219 is rotatable about the shaft member 220 so that the distance from the main shaft center line AX2 to the sliding contact portion 219b changes. The shifter 221 is movable in the forward direction D1 and the backward direction D2. A lever 223 is connected to the shifter 221 via a bearing 222 . Lever 223 is rotatable around shaft member 227 . An actuator 225 is connected to the lever 223 via a shaft member 224 . An electric cylinder, an air cylinder, a hydraulic cylinder, or the like can be used for the actuator 225 .

When the NC device 70 shown in FIG. 5 drives the actuator 225 to rotate the lever 223 counterclockwise in FIG. 6, the shifter 221 moves in the right direction D84, and the sliding contact portion 219b moves toward the spindle center line AX2. Each claw member 219 is rotated in a direction away from the . As a result, the engaging portion 219a of each claw member 219 pushes the push sleeve 211 and the chuck sleeve 209 in the left direction D83, tightens the collet 213 via the tapered portions 209a and 213b, and causes the collet 213 to grip the workpiece W1.
On the other hand, when the NC device 70 drives the actuator 225 to rotate the lever 223 clockwise in FIG. 6, the shifter 221 moves leftward D83. Then, the coil spring 215 pushes the engagement portion 219a of each pawl member 219 in the right direction D84 via the chuck sleeve 209 and the push sleeve 211. As shown in FIG. Each claw member 219 rotates so that the sliding contact portion 219b approaches the spindle center line AX2, and the work W1 is released from the clamping of the collet 213. As shown in FIG.

The push rod 23 has an ejector pin 30 replaceably attached to its front end 23a as shown in FIG. It is possible to move to The push rod 23 has a female threaded portion 23d at the front end 23a for attaching the ejector pin 30, and is inserted through the cylindrical holding member 24 at a midway position in the longitudinal direction of the push rod 23 along the main shaft centerline AX2. It has a large-diameter portion 23c that does not allow the In the push rod 23, a tubular holding member 24 can be passed through an insertion portion 23e located forward of the large-diameter portion 23c. A rear side portion 23 f located on the rear side of the large diameter portion 23 c is passed through an annular rear side holding member 26 attached inside the rear main shaft 21 . A coil spring 25 that applies a force in the forward direction D1 to the large-diameter portion 23c is arranged outside the rear portion 23f.

The ejector pin 30 shown in FIG. 7 is an assembly 31 of the ejector pin main body 40 and the contact member 45 . Details of the replaceable ejector pin 30 will be described later.

A substantially cylindrical holding member 24 is arranged inside the chuck sleeve 209 and the pressing sleeve 211 . The holding member 24 is arranged outside the push rod 23 around the main shaft center line AX2, and holds the push rod 23 at the axial position around the main shaft center line AX2. The axial position of the push rod 23 is a position where the center of the push rod 23 is aligned with the main shaft center line AX2, as shown in FIGS. A large-diameter portion 23c of the push rod 23 to which force is applied in the forward direction D1 by a coil spring 25 is hooked on the rear end of the holding member 24. As shown in FIG. The outer surface of the holding member 24 is inserted into the through hole of the chuck sleeve 209 on the front side of the midway position (engagement portion 24c) in the longitudinal direction of the holding member 24 along the spindle centerline AX2. The holding member 24 is attached to the chuck sleeve 209 by screwing, for example. The engaging portion 24 c shown in FIGS. 6 and 7 is a portion of the outer surface of the holding member 24 that is fitted to the rear end of the chuck sleeve 209 . Since the holding member 24 is attached to the chuck sleeve 209 on the front side of the engaging portion 24c, the holding member 24 to which a force in the forward direction D1 is applied from the coil spring 25 via the large-diameter portion 23c moves toward the chuck sleeve. 209 and the push sleeve 211.

The coil spring 25 arranged outside the rear portion 23f of the push rod 23 is a compression coil spring that exists between the large-diameter portion 23c of the push rod 23 and the engagement portion 21c of the back main shaft 21 in the Z2-axis direction. be. That is, the front end of the coil spring 25 abuts against the large-diameter portion 23c, and the rear end of the coil spring 25 abuts against the engaging portion 21c. The coil spring 25 pushes out the workpiece W1 released from the gripping mechanism 22 with the ejector pin 30 by applying a force in the forward direction D1 to the push rod 23 having the insertion portion 23e passing through the holding member 24 .

FIG. 8 schematically illustrates various ejector pins 30 that can be attached to the front end 23a of the push rod 23. FIG.
The attachable ejector pin 30 includes an assembly 31 of the ejector pin body 40 and the backing member 45 and an integrated ejector pin 32 . The concept of the aggregate 31 includes the aggregates 31A and 31B, the concept of the ejector pin main body 40 includes the ejector pin main body 40A, and the concept of the contact member 45 includes the contact members 45A and 45B. This embodiment is characterized in that the assembly 31 and integral ejector pin 32 are interchangeably attached to the front end 23a of the push rod 23. As shown in FIG.

The ejector pin body 40 of the assembly 31 can be passed through the cylindrical holding member 24 and is detachably attached to the front end 23a of the push rod 23. As shown in FIG. The ejector pin main body 40 has a male threaded portion 41 at the rear end 40b that is screwed with the female threaded portion 23d at the front end 23a of the push rod 23, and a female threaded portion 42 that is screwed with the male threaded portion 46 of the backing member 45 at the front end 40a. have.
The contact member 45 of the assembly 31 is detachably attached to the front end 40a of the ejector pin body 40. As shown in FIG. The contact member 45 has a male threaded portion 46 at a rear end 45b that is screwed with the female threaded portion 42 at the front end 40a of the ejector pin body 40, and a contact portion 47 that contacts the workpiece W1 at the front end 45a. The abutting portion 47 shown in FIG. 8 has an outer diameter larger than the outer diameter of the insertion portion 23e of the push rod 23. As shown in FIG.

Integral ejector pin 32 is threadable through tubular retainer member 24 from rear end 32b to front end 32a. The integrated ejector pin 32 has a male threaded portion 33 at its rear end 32b which is screwed with the female threaded portion 23d at the front end 23a of the push rod 23, and a contact portion 34 which contacts the workpiece W1 at its front end 32a. That is, the integrated ejector pin 32 can be passed through the holding member 24 from the attachment portion (male screw portion 33) to the push rod 23 to the portion (contact portion 34) that contacts the workpiece W1.

An assembly 31A shown in FIG. 8 may be attached to the front end 23a of the push rod 23. The assembly 31A includes an ejector pin main body 40A having a male threaded portion 43 at the front end 40a, and an abutment member 45A having a female threaded portion 48 that screws together with the male threaded portion 43A. The contact member 45A is detachably attached to the front end 40a of the ejector pin body 40 by the male threaded portion 43 and the female threaded portion 48. As shown in FIG.
8 may be attached to the front end 23a of the push rod 23. As shown in FIG. The assembly 31B includes an ejector pin body 40 having a female threaded portion 42 at the front end 40a that engages with the male threaded portion of the screw SC1, and a backing member 45B having a screw insertion hole 49 through which the male threaded portion of the screw SC1 is passed. The contact member 45B is detachably attached to the front end 40a of the ejector pin body 40 with a screw SC1.

By the way, it is difficult to make the contact portion 34 of the integrated ejector pin 32 larger in outer diameter than the insertion portion 23 e of the push rod 23 . The reason will be described with reference to FIG.

FIG. 18 schematically illustrates the inner diameter Dh of the substantially cylindrical holding member 24, the outer diameter De of the integrated ejector pin 32, the outer diameter Dw of the workpiece W1, and the inner diameter dw of the workpiece hole W1h. The work hole W1h is a hole formed at least at the rear end of the work W1, and in the example shown in FIG. 18, it is a through hole penetrating along the spindle center line AX2. The lower part of FIG. 18 schematically illustrates how the push rod 23 to which the integrated ejector pin 32 is attached is passed through the holding member 24 .
As shown in FIG. 18, when the work W1 has a work hole W1h, in order to push out the work W1 from the back spindle 21, the outer diameter De of the contact portion 34 of the integrated ejector pin 32 must be larger than the inner diameter dw of the work hole W1h. need to be bigger. When it is necessary to make the outer diameter De of the contact portion 34 larger than the inner diameter Dh of the holding member 24 in order to push out the work W1 having the work hole W1h, the state where the push rod 23 to which the integrated ejector pin 32 is attached exists. Therefore, the chuck sleeve 209 to which the holding member 24 is attached cannot be inserted into the back spindle 21 from the front end of the back spindle 21 . When using the integrated ejector pin 32, in order to maximize the outer diameter De of the contact portion 34, the inserting portion 23e of the push rod 23 is designed to be as large as possible, and the inner diameter Dh of the holding member 24 is designed to be as large as possible. There is a need.

Here, as in the comparative example shown in FIG. Suppose. In this case, as shown in FIG. 19, only the cap 216 and the collet 213 are removed from the back spindle 21, and the push rod 23 is inserted into the chuck sleeve 209 and the holding member 24. After attaching the ejector pin 932 , it is necessary to attach the collet 213 and the cap 216 to the back spindle 21 . Here, as shown in FIG. 19, the push rod 23 can only move forward until the large-diameter portion 23c hits the rear end of the holding member 24. As shown in FIG. The front end 23a of the push rod 23 is within the chuck sleeve 209 even when the push rod 23 is most advanced. Therefore, the operator needs to attach the integrated ejector pin 932 to the front end 23 a of the push rod 23 within the chuck sleeve 209 . Therefore, workability for attaching the integrated ejector pin 932 is not good.

In this specific example, as illustrated in FIG. 9, a contact member 45 having an outer diameter Dp larger than the inner diameter Dh of the holding member 24 is attached to the front end 40a of the ejector pin body 40 having an outer diameter smaller than the inner diameter Dh of the holding member 24. is attached. Since the assembly 31 including the ejector pin main body 40 and the contact member 45 is attached to the front end 23a of the push rod 23, the workability of attaching the ejector pin 30 corresponding to the shape of the work W1 to the front end 23a of the push rod 23 is improved. improves. FIG. 9 schematically illustrates the inner diameter Dh of the substantially cylindrical holding member 24, the outer diameter Dp of the contact member 45, the outer diameter Dw of the workpiece W1, and the inner diameter dw of the workpiece hole W1h.
When the work W1 has a work hole W1h as shown in FIG. 9, in order to push out the work W1 from the back spindle 21, the outer diameter Dp of the contact member 45 must be larger than the inner diameter dw of the work hole W1h. When it is necessary to make the outer diameter Dp of the contact member 45 larger than the inner diameter Dh of the holding member 24 in order to push out the work W1 having the work hole W1h, the contact member 45 cannot be passed through the cylindrical holding member 24. As illustrated in FIG. 10, the work ejecting device 100 of this specific example can attach the abutment member 45 to the front end 40a of the ejector pin main body 40 with only the cap 216 and collet 213 removed from the back main shaft 21.

In the example shown in FIG. 10 , the ejector pin body 40 is attached to the front end 23 a of the push rod 23 that is not inserted into the back main shaft 21 , and the ejector pin body 40 and the push rod 23 are attached to the back main shaft 21 from the front end of the back main shaft 21 . After insertion, the chuck sleeve 209 with the holding member 24 attached can be inserted into the back spindle 21 from the front end of the back spindle 21 . When the push rod 23 is most advanced to the position where the large-diameter portion 23 c hits the rear end of the holding member 24 , the front end 40 a of the ejector pin body 40 protrudes forward from the front end of the chuck sleeve 209 . This makes it possible to easily attach the contact member 45 to the front end 40a of the ejector pin body 40 while the push rod 23 is moving forward. Even if the abutment member 45 cannot be passed through the cylindrical holding member 24, the abutment member 45 can be attached to the front end 40a of the ejector pin body 40 after passing the ejector pin body 40 and the push rod 23 through the holding member 24. , the abutting member 45 that cannot be passed through the holding member 24 can be arranged on the front side of the holding member 24 . Therefore, in this specific example, the workability of attaching the ejector pin 30 corresponding to the shape of the work W1 to the front end 23a of the push rod 23 can be improved.

Further, when the workpiece W1 is thin, it is necessary to reduce the inner diameter of the collet 213 for gripping the workpiece W1. If the integrated ejector pin 32 can be passed through the cylindrical holding member 24, the integrated ejector pin 32 is attached to the front end 23a of the push rod 23 that is not inserted into the back main shaft 21, and the integrated ejector pin 32 is attached to the back main shaft 21. After the ejector pin 32 and push rod 23 are inserted from the front end of the main shaft (21), the chuck sleeve 209 with the holding member 24 attached can be inserted into the back main shaft 21 from the front end of the back main shaft 21. In this case, the operation of attaching the contact member 45 to the front end 40a of the ejector pin main body 40 becomes unnecessary. Since the integrated ejector pin 32 can be attached to the front end 23a of the push rod 23 in addition to the assembly 31 including the ejector pin main body 40 and the backing member 45, this embodiment can flexibly deal with various workpieces W1. is possible and economical.

As described above, the push rod 23 to which the assembly 31 can be attached only needs to be thick enough to form a mounting portion for mounting the ejector pin 30 on the front end 23a. In this specific example, the work W1 having the work hole W1h having the inner diameter dw larger than the outer diameter of the push rod 23 can be pushed out by the contact member 45 and discharged. Since the push rod 23, which is a rotating body, can be designed to be thinner than before, vibration of the rotating body can be reduced by weight reduction, and the manufacturing cost of the push rod 23 can be reduced. Moreover, even if the front end of the ejector pin 30 wears out, only the contact member 45 needs to be replaced, so the running cost can be reduced. Furthermore, it is possible to flexibly deal with not only the workpiece W1 having the workpiece hole W1h but also various parts with different diameters.

The mounting structure of the abutment member 45 to the ejector pin body 40 is not limited to screwing between the male threaded portion and the female threaded portion. Further, the ejector pin main body 40 may be divided into two or more parts, and the contact member 45 may also be divided into two or more parts. Furthermore, the work discharge device 100 is not limited to being assembled on the back spindle 21 and may be assembled on the front spindle 11 .

(4) Specific example of door device:
The lathe 1 of this specific example is characterized by a door device 300 shown in FIGS. In the description of the door device 300, the front direction D85 will be described as the front direction, that is, the front side will be described as the front side, and the depth direction D86 will be described as the rear direction, that is, the back side as the rear side.
The exterior 2 shown in FIGS. 1-3 has a substantially horizontal ceiling portion 2a and a front portion 2b depending from the front edge of the ceiling portion 2a. The exterior 2 has an opening 2op from the ceiling portion 2a to the front portion 2b. The door 3 included in the door device 300 is attached to the exterior 2 and can be changed between a closed position that closes the opening 2op as shown in FIG. 1 and an open position that opens the opening 2op as shown in FIGS. is. The door rails 4 included in the door device 300 are provided on both the left and right sides of the opening 2op, and as shown in FIG. 350 included. Each upper rail portion 340 includes a front horizontal portion 341 and a rear inclined portion 342 . The horizontal portion 341 extends in the depth direction D86 from the connection portion with the front rail portion 350, and the inclined portion 342 extends from the rear end of the horizontal portion 341 to the rear end of the upper rail portion 340 slightly downward in the depth direction D86. Each front rail section 350 includes an upper steep section 351 and a lower vertical section 352 . The steep slope portion 351 extends slightly forward from the connecting portion with the upper door 310 in the downward direction D82, and the vertical portion 352 extends from the lower end of the steep slope portion 351 to the lower end of the front rail portion 350 in the downward direction D82.

As shown in FIGS. 1 and 3, the door 3 includes an upper door 310 aligned with the ceiling part 2a in the closed position, a lower door 320 aligned with the front part 2b in the closed position, and assisting the operation of opening the door 3. A damper 330 is provided.

The upper door 310 has a substantially rectangular plate shape that is aligned with a portion of the opening 2op corresponding to the ceiling portion 2a, and is rotatably connected to the ceiling portion 2a at a rotating portion 311 provided at the rear edge portion. ing. Since the rotation axis of the rotating portion 311 is directed to the left and right, the upper door 310 is rotatable about the rotating portion 311 so that the front edge portion moves up and down.
The front door 320 has a substantially rectangular plate shape that is aligned with a portion of the opening 2op that corresponds to the front surface portion 2b, and rotates with respect to the front edge portion of the upper door 310 at a rotating portion 321 provided at the upper edge portion. movably connected. The front door 320 has a pair of sliders 324 that protrude outward from the lower edge. Each slider 324 is inserted into the door rail 4 and can slide along the door rail 4 . Since the rotating shaft of the rotating portion 321 faces left and right, and the pair of sliders 324 function as rotating shafts facing left and right, the door 3 can be folded at the rotating portion 321 as shown in FIG. The front door 320 further has a transparent window 322 for viewing the processing chamber C1 from the door 3 in the closed position, and a handle 323 for opening and closing the door 3 .

The damper 330 has a base end portion 331 that is rotatable at a fixed position slightly forward and below the rotating portion 311 of the upper door 310 , and a midway position from the rotating portion 311 to the front edge portion of the upper door 310 . It has a tip 332 pivotally connected to the portion. When the door 3 switches from the closed position to the open position, the damper 330 extends, and when the door 3 switches from the open position to the closed position, the damper 330 contracts. The damper 330 applies force in the direction in which the damper 330 extends to the upper door 310 , so that the force is applied in the direction in which the door 3 opens as a whole.

As a comparative example, when the entire upper rail portion 340 is horizontal, if the slider 324 of the front door 320 is at a midway position corresponding to the inclined portion 342 shown in FIG. moves forward in the upper rail portion 340 in the direction D85. As a result, the door 3 is in a half-open state in which it cannot be fully opened, and the workability of maintenance of the machining parts such as the guide bush 15 and the comb-shaped tool post 50 in the machining chamber C1 is lowered. Adding a damming component that holds the door 3 in the open position leads to an increase in the cost of the door device 300 .

The upper rail portion 340 of the door device 300 shown in FIGS. 1 to 3 includes an inclined portion 342 extending slightly downward from the rear end of the horizontal portion 341 in the depth direction D86. When the slider 324 of the front door 320 is in the middle position of the inclined portion 342, the slider 324 is guided by the inclined portion 342 and moves rearward. As a result, as shown in FIG. 3, the door 3 is in the open position where it is completely opened, and the maintenance workability of the machining parts such as the guide bush 15 and the comb-shaped tool post 50 in the machining chamber C1 is improved.

(5) Specific example of sleeve holder and turret table:
FIG. 11 is a perspective view schematically showing the tool post table 51 and the sleeve holder 60 without the tool T1 or the like attached. FIG. 12 is a diagram schematically illustrating the size of the sleeve holder 60 of this specific example compared with the sleeve holder 860 of the reference example. FIG. 13 is a longitudinal sectional view schematically illustrating the interior of a sleeve holder 60 compared with the sleeve holder 860 of the reference example. 14 is a cross-sectional view of the sleeve holder 60 taken along line A1-A1 in FIG. 13. FIG.

The tool post table 51 shown in FIG. 11 has an extension portion 51e extending upward D81 from the upper portion 51a. A mounting portion 51f for mounting a ball screw included in the gang tool post drive portion DR4 shown in FIG. 5 is provided at the upper end of the extension portion 51e. The aforementioned ball screw is a component for moving the tool post table 51 in the Y1-axis direction. In the near side vertical portion 51c and the far side vertical portion 51d, the surfaces facing the front headstock 10, that is, the surfaces opposite to the surface 51z on which the sleeve holder 60 is mounted, are respectively provided with gang tool post drive portions DR4. A recessed guide mounting portion 51g is formed for mounting the linear guide included in the . The aforementioned linear guide is a component for moving the tool rest table 51 in the Y1-axis direction. Therefore, each guide mounting portion 51g is a portion that is thinner than the surrounding portion along the Y1 axis direction, and is thinner than the upper portion 51a.
The tool post table 51 has an opening OP1 in which the distance between the upper portion 51a and the lower portion 51b is wider than the distance between the front side vertical portion 51c and the depth side vertical portion 51d.

The sleeve holder 60 shown in FIGS. 11 to 14 is made of metal, and includes an attachment portion 61 attached to the upper portion 51a of the tool post table 51, a holding portion 62 for holding a plurality of tool units U1, and an attachment portion 61 to the holding portion. It has a connecting part 63 connected to 62 . The mounting portion 61 has a plurality of screw insertion holes 61a through which screws (not shown) are threaded into screw holes (not shown) in the upper portion 51a of the tool post table 51 . FIGS. 11 and 12 show the attachment portion 61 having four screw insertion holes 61a surrounding the communication portion 63. As shown in FIGS. The holding portion 62 has a plurality of holding holes 62a into which the tool unit U1 is inserted so as to protrude in the left direction D83 and the right direction D84. 11 and 12 show the holding portion 62 having five holding holes 62a. As shown in FIG. 13, when a force F1 in the Z1-axis direction is applied to the tool unit U1, a force that bends the connecting portion 63 is applied. The communication portion 63 has an octagonal cross-sectional shape as shown in FIG. As shown in FIG. 13 , the sleeve holder 60 has a hollow portion 64 spanning the mounting portion 61 and the connecting portion 63 . The attachment portion 61 has an opening 61op connected to the hollow portion 64 on the surface attached to the tool rest table 51 . As shown in FIG. 14 , the shape of the cross section of the hollow portion 64 in the communication portion 63 is an octagon along the outer shape of the communication portion 63 .

For convenience, the outer surface of the connecting portion 63 is divided into surfaces 63a to 63h aligned with the sides of the octagonal cross section. Here, the surface 63a is the upper surface, the surface 63e is the lower surface, the surface 63g is the front surface, the surface 63c is the rear surface, and the surface 63b is the surface 63a and the surface 63c. , surface 63d is between surfaces 63c and 63e, surface 63f is between surfaces 63e and 63g, and surface 63h is between surfaces 63g and 63a.

The sleeve holder 860 of the reference example shown in FIGS. 12 and 13 is made of metal and is attached to the surface 51z of the back side vertical portion 51d of the tool post table 51 facing the back headstock 20 . For comparison with the sleeve holder 60, the orientation of the sleeve holder 860 is changed to match the sleeve holder 60 in FIGS. The sleeve holder 860 includes a mounting portion 861 having a plurality of screw insertion holes 861a, a holding portion 862 having a plurality of holding holes 862a, and a communication portion 863 connecting the mounting portion 861 to the holding portion 862. The attachment portion 861 and the communication portion 863 are substantially solid.
Here, L1 is the distance from the screw insertion hole 61a closest to the holding portion 62 to the center of the holding hole 62a furthest when viewed from the central axis direction of the tool unit U1. The distance from the screw insertion hole 861a closest to the holding portion 862 to the center of the holding hole 862a furthest from the holding portion 862 is L9. Since the opening OP1 of the tool rest table 51 is wider in the Y1-axis direction than in the X1-axis direction, the distance L1 in the sleeve holder 60 of this specific example is longer than the distance L9 in the sleeve holder 860 of the reference example.

When it is necessary to attach the sleeve holder 60 to the upper portion 51a of the tool rest table 51, it is necessary to satisfy L1>L9 for the above reasons. The reason why L1>L9 must be satisfied is also to avoid interference with a coolant discharge unit (not shown). If the mounting portion 61 and the connecting portion 63 are substantially solid, the sleeve holder 60 becomes heavier than the sleeve holder 860 of the reference example. When compared with the sleeve holder 860 of the reference example, the natural frequency of the sleeve holder 60 is lowered, and unfavorable vibrations are likely to occur during processing. Further, when the gang tool post 50 is accelerated or decelerated, the load applied to the axial feed motor of the gang tool post drive unit DR4 increases.

Therefore, the sleeve holder 60 of this specific example has a weight similar to that of the sleeve holder 860 of the reference example by forming a hollow portion 64 in the attachment portion 61 and the communication portion 63 as shown in FIG. As a result, the natural frequency of the sleeve holder 60 is increased, and undesirable vibrations are less likely to occur during processing. In addition, the load on the axial feed motor of the gang tool post drive unit DR4 is reduced when the gang tool post 50 is accelerated or decelerated.

Further, in order to suppress the decrease in rigidity due to the weight reduction of the sleeve holder 60, the width w1 of the mounting portion 61 of this specific example is made wider than the width w9 of the mounting portion 861 of the reference example, as shown in FIG. Here, the width w1 is the length of the mounting portion 61 in the direction orthogonal to the direction from the mounting portion 61 to the holding portion 62 when viewed from the central axis direction of the tool unit U1. The width w9 is the length of the mounting portion 861 in the direction orthogonal to the direction from the mounting portion 861 to the holding portion 862 when viewed from the central axis direction of the tool unit U1. The length of the mounting portion 61 in the direction from the mounting portion 61 to the holding portion 62 when viewed from the central axis direction of the tool unit U1 is substantially the same. Since w1>w9, the mounting portion 61 of this specific example has a larger area than the mounting portion 861 of the reference example when viewed from the central axis direction of the tool unit U1.

Further, in the tool post table 51, the upper portion 51a to which the sleeve holder 60 of this specific example is attached is thicker than the depth side vertical portion 51d having the guide attachment portion 51g. As a result, the tool post table 51 having the sleeve holder 60 of this specific example attached to the upper portion 51a has higher rigidity than the tool post table 51 having the sleeve holder 860 of the reference example attached to the back side vertical portion 51d. there is

If the outer shape of the communication portion 63 of the sleeve holder 60 attached to the upper portion 51a of the tool post table 51 is rectangular in cross section, the communication portion 63 may make it difficult to supply coolant to the workpiece W1 (see FIG. 4). be. The connecting portion 63 of this specific example has an outer shape of an octagonal cross section, and particularly has oblique surfaces 63d and 63f facing downward. Therefore, the communication portion 63 does not become an obstacle when supplying coolant to the work W1, and the coolant can be easily supplied to the work W1.

As described above, the turret table 51 with the sleeve holder 60 attached to the upper portion 51a has a reduced weight and good rigidity. Although the sleeve holder 60 is made of metal, the sleeve holder may be made of a lighter and more rigid material such as carbon or ceramic.

(6) Specific example of cover structure for processing chamber:
In the machining chamber C1 shown in FIGS. 1 and 2, the lathe 1 processes the workpiece W1 with a tool post such as a comb-shaped tool post 50 and a back machining tool post 59 while supplying coolant to the work W1 from a coolant supply unit 5. do. On the other hand, in the headstock chamber C2, a shaft feed motor included in the front headstock drive unit DR1 and a shaft feed motor included in the gang tool post drive unit DR4 are arranged. In order to prevent coolant from entering the headstock chamber C2 from the machining chamber C1, a tool post cover or the like is arranged in the headstock chamber C2, and an exterior cover or the like is arranged in the machining chamber C1.

FIG. 15 is a diagram schematically illustrating the cover structure 400 of this specific example compared with the cover device 700 of the reference example. FIG. 16 is a perspective view schematically illustrating the lathe 1 with the exterior cover 420 removed from the exterior member 410. FIG. FIG. 17 is a perspective view schematically illustrating the lathe 1 with the exterior cover 420 attached to the exterior member 410. FIG.

The cover structure 400 of this specific example shown in FIGS. 15 to 17 includes an exterior member 410 forming part of the exterior 2 shown in FIGS. includes a turret cover 430 located in the . The tool post cover 430 is arranged on the headstock chamber C2 side at the boundary between the machining chamber C1 and the headstock chamber C2. The exterior cover 420 is attached to the exterior member 410 with screws SC2, and is arranged on the machining chamber C1 side at the boundary between the machining chamber C1 and the headstock chamber C2. The exterior member 410 has an elongated hole 411 as a screw insertion hole for passing the screw SC2. The female threaded portion to be screwed with the screw SC2 may be provided on the exterior cover 420 itself or may be provided on the nut.

A cover device 700 of a reference example shown in the lower part of FIG. 15 includes an exterior member 710 integrated with a cover portion 720 arranged in the machining chamber C1, and a tool post cover 730 arranged in the headstock chamber C2. there is Since the exterior member 710 has a large number of components, dimensional errors are large. Therefore, CL9 between the cover portion 720 and the tool post cover 730 in the Z1-axis direction must be increased. In order to prevent the coolant and chips from the work W1 from entering the headstock chamber C2 from the machining chamber C1, the overlapping margin 740 between the cover portion 720 and the tool post cover 730 is increased. Chips from the workpiece W1 enter the headstock chamber C2.

The cover structure 400 of this specific example includes a fitting adjustment means that makes the gap CL1 between the exterior cover 420 and the tool post cover 430 in the Z1-axis direction smaller than the gap CL9 of the reference example. As shown in FIGS. 15 and 17, the exterior member 410 has an elongated hole 411 that is long in the Z1-axis direction as a screw insertion hole for passing the screw SC2. As a result, the mounting position of the exterior cover 420 with respect to the exterior member 410 can be adjusted in the Z1-axis direction, and the clearance CL1 between the exterior cover 420 and the tool post cover 430 in the Z1-axis direction is larger than the clearance CL9 of the reference example. can be reduced. Therefore, the cover structure 400 of this specific example can prevent coolant and chips from the work W1 from entering the headstock chamber C2 through the clearance CL1. Note that the screw insertion hole for passing the screw SC2 may be any hole other than the elongated hole 411, such as an elliptical hole or a round hole slightly wider than the screw, as long as the fixing position of the screw SC2 can be adjusted.

(7) Modification:
Various modifications of the present invention are conceivable.
For example, the lathe is not limited to a movable spindle type lathe, and may be a fixed spindle type lathe in which the front headstock 10 does not move, or a lathe with a fixed spindle in which the front headstock 10 does not move, or a lathe in which the front headstock 10 does not move in the Z2-axis direction and the front headstock 10 moves in the Z1-axis direction. A lathe that moves to Furthermore, this technology can also be applied to lathes that do not have a back headstock.
The moving direction of the driven object in the lathe is not limited to the specific examples described above.

(8) Knot:
INDUSTRIAL APPLICABILITY As described above, according to the present invention, it is possible to provide a technique for a machine tool or the like that can improve the workability of attaching an ejector pin to the front end of a push rod in accordance with the shape of a workpiece. can. Of course, the above-described basic actions and effects can be obtained even with a technique consisting only of the constituent elements of the independent claims.
In addition, a configuration in which each configuration disclosed in the above examples is replaced with each other or the combination thereof is changed, and each configuration disclosed in the known technology and the above example is replaced with each other or the combination thereof is changed. , etc. can also be implemented. The present invention also includes these configurations and the like.

1... lathe (example of machine tool), 2... exterior, 3... door, 4... door rail,
DESCRIPTION OF SYMBOLS 10... Front headstock, 11... Front spindle, 12... Collet, 15... Guide bush,
20... Back headstock,
21... back spindle (example of spindle), 21a... front end, 21h... through hole,
22 ... gripping mechanism,
23 Push rod 23a Front end 23c Large-diameter portion 23d Female screw portion 23e Insertion portion
24... Holding member, 24c... Engagement part,
25... Coil spring (example of extrusion mechanism),
26... Rear side holding member,
30... ejector pin, 31, 31A, 31B... assembly,
32...Integrated ejector pin, 32a...front end, 32b...rear end,
33... male screw part (example of mounting part), 34... contact part (example of part that comes into contact with a work),
40, 40A... ejector pin main body, 40a... front end, 40b... rear end,
41... male screw part, 42... female screw part, 43... male screw part,
45, 45A, 45B... backing member, 45a... front end, 45b... rear end, 46... male screw portion,
47... Contact part, 48... Female screw part, 49... Screw insertion hole,
50 ... comb-shaped tool post,
51... Tool post table, 51a...Upper part, 51c...Front side vertical part, 51d... Back side vertical part,
60... Sleeve holder, 61... Mounting part, 62... Holding part, 63... Communication part, 64... Hollow part,
100 ... work discharge device,
209... chuck sleeve, 211... push sleeve, 213... collet,
215... Coil spring, 216... Cap, 219... Claw member, 221... Shifter,
223... lever, 225... actuator,
300...Door device, 310...Upper door, 320...Front door, 330...Damper,
340... Upper rail portion, 341... Horizontal portion, 342... Inclined portion, 350... Front rail portion,
400 ... cover structure,
410 ... exterior member, 411 ... long hole, 420 ... exterior cover, 430 ... tool post cover,
AX1, AX2...spindle center line,
C1... machining chamber, C2... headstock chamber,
D1...forward direction, D2...reverse direction,
D81...upward, D82...downward, D83...leftward, D84...rightward,
D85...front direction, D86...back direction,
W1... work, W1h... work hole.

Claims (2)

a spindle rotatable about the spindle centerline;
a gripping mechanism for releasably gripping a workpiece at the front end of the spindle;
a push rod inserted into the main shaft and movable in a forward direction for pushing out the work and a backward direction opposite to the forward direction;
an ejector pin replaceably attached to the forward end of the pushrod;
a holding member disposed outside the push rod around the center line of the main shaft and holding the push rod at an axial position around the center line of the main shaft;
a pushing mechanism for pushing out the workpiece released from the gripping mechanism with the ejector pin by applying force in the forward direction to the push rod passing through the holding member;
an ejector pin body that can be passed through the holding member and that is detachably attached to the front end of the push rod; and a backing member that is detachably attached to the front end of the ejector pin body. is attached to the front end of said push rod as said ejector pin. At the front end of the push rod, the assembly and an integrated ejector pin that can be passed through the holding member from the attachment portion to the push rod to the portion that contacts the work are replaceably attached as the ejector pin. A machine tool according to claim 1.

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