JP2003311513A - Tool rest for machine tool - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tool rest for machine tool having a simple-structure lock mechanism composed of a small number of parts and enabling stable position determination. <P>SOLUTION: A lock mechanism 45 for positioning and fixing a turret head 4 and a milling unit 6 so as to align the center of an input shaft 8, indexed for a processing location A of the lock mechanism, and the center of an output shaft 9 with each other is installed, and the lock mechanism 45 is so composed that the turret head 4 is provided with a positioning pin 47 which can be fitted in an engagement hole 48 of the milling unit and retracted therefrom and the positioning pin 47 is operated by hydraulic pressure for clamping. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for a machine tool in which a turret head having a plurality of tool holders mounted on its outer peripheral portion is rotationally indexed and clamped so that a required tool holder is located at a machining position. Regarding the stand.

[0002]

2. Description of the Related Art For example, in a tool rest such as an NC lathe, a tool holder on which a rotary tool is mounted is rotationally indexed and clamped so as to be positioned at a predetermined machining position, and the rotary tool is driven to rotate. There is a case where it is configured to perform the processing.

This type of turret includes a turret head having a plurality of tool holders mounted on its outer periphery at predetermined angular intervals, a turret head body for supporting the turret head in a rotationally indexable and clampable manner, and the turret. And a milling unit provided with an output shaft that is non-rotatably supported by the table body and that engages with the input shaft of the tool holder indexed to the machining position in a disengageable manner.

In such a tool rest, since the turret head rotates with respect to the fixing of the milling unit,
Every time the turret head is indexed to the machining position, it is necessary to align the output shaft of the milling unit with the input shaft of the tool holder. In this case, the milling unit has a high positioning accuracy in the axial direction with respect to the turret head, but the positioning accuracy in the circumferential direction is low, and therefore the axis of the output shaft and the input shaft may be misaligned. That is, the circumferential positioning of the milling unit is due to the spline groove provided in the rear part of the tool rest body,
It is difficult to align the shaft cores due to distortion of parts, rattling of spline grooves, etc., which may cause clutch failure, heat generation, or noise.

Therefore, in order to solve the problems of clutch error and noise, there is a conventional one equipped with a lock mechanism as shown in FIG. 4 (see Japanese Patent Laid-Open No. 5-285709).
In this unclamping state, the lock pin 61 is urged to the standby position by the spring 62 and the operating pin 6
7 is also biased to the standby position by the spring 68. As a result, the turret head 100 can be rotationally indexed. In this state, the turret head 100 is rotationally indexed to a predetermined processing position, moved toward the tool rest body 101 side, and the coupling 102 is engaged and clamped. Then, by this clamping operation, the operation pin 67 abuts against the tool rest main body 101 and is pushed out to rotate the movable lever 63, the movable lever 63 presses the lock pin 61, and the lock pin 61 engages with the turret head 100. It enters into the fitting hole 69 and engages. As a result, the milling unit 103 is positioned and fixed to the turret head 100, and the axes of the output shaft and the input shaft match. Incidentally, 64 is a pin that pivotally supports the movable lever 63, and 65
Is a follow pin that urges the movable lever 63 to contact the lock pin 61 by the spring 66.

[0006]

However, the lock mechanism of the above-mentioned prior art requires a lock pin, an actuating lever, an actuating pin, a follow pin, and a spring for urging each pin, and therefore the number of parts is large and the structure is large. There is a problem that it is complicated, and because it is difficult to secure a space for arranging these, there is a limit to the number of lock mechanisms that can be arranged, and there is a possibility that positioning becomes unstable. Has been requested.

The present invention has been made in view of the above circumstances, and provides a tool post of a machine tool that has a simple structure, can configure a lock mechanism with a small number of parts, and can perform stable positioning. Is intended.

[0008]

According to a first aspect of the invention, a tool rest body is rotatably and axially movably supported, and a plurality of tool holders are mounted at predetermined circumferential angular intervals. A turret head, a rotary indexing mechanism for rotating and indexing the turret head so that the required tool holder is located at a predetermined machining position, and a rotary indexing mechanism for clamping the turret head at the machining position, and the turret head being non-rotatable to the tool rest body. And a milling unit having an output shaft that is supported so as to be axially movable together with the input shaft of the rotary tool of the tool holder that is indexed to the machining position, and a rotary tool that rotationally drives the output shaft. In a tool post of a machine tool provided with a drive mechanism, the turret head such that the input shaft indexed to the processing position and the output shaft coincide with each other. A lock mechanism for positioning and fixing the milling unit is provided, and the lock mechanism can be retracted between the fitting position where the positioning pin is fitted to the turret head and the release position where the fitting is released. It is characterized in that it is arranged and the positioning pin is operated by fluid pressure.

According to a second aspect of the invention, in the first aspect, the fluid pressure is commonly used as a clamping hydraulic pressure for clamping the turret head, and the positioning pin is interlocked with the clamping operation by the clamping hydraulic pressure. It is characterized in that it is configured to operate.

[0010]

According to the lock mechanism of the present invention, when the required tool holder is indexed to the machining position and clamped at the machining position, the positioning pin projects due to fluid pressure and fits into the milling unit. Become. As a result, the milling unit is positioned and fixed to the turret head that is clamped to the tool rest body, so that the axis of the input shaft and the output shaft that are indexed to the machining position can be aligned, and during milling It is possible to avoid the problem that the unit and the turret head are misaligned, and it is possible to prevent clutch mistakes, heat generation, and noise generation.

According to the lock mechanism of the present invention, the turret head is provided with positioning pins so that the positioning pins can be retracted, and the positioning pins are fitted and fixed to the milling unit by fluid pressure. The structure is simpler than the link type with levers and levers,
The number of parts can be reduced.

Further, in the present invention, it is only necessary to secure a space for disposing the positioning pin in the turret head, and it is possible to save space. As a result, the number of lock mechanisms arranged can be increased, and stable positioning can be performed.

According to the second aspect of the present invention, the positioning pin is operated in conjunction with the clamping operation of the turret head by the clamping hydraulic pressure. Therefore, the clamping hydraulic pressure can be effectively utilized to drive the positioning pin. It can be simplified and the responsiveness of the positioning pin can be improved.
For example, it is possible to use compressed air as the fluid pressure. However, when compressed air is used, the positioning pin response is lower than hydraulic pressure, and compressed air is supplied separately from the clamp operation hydraulic pressure supply unit. Need to be formed.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings.

1 to 3 are views for explaining a tool rest of a machine tool according to an embodiment of the present invention.
2 is a schematic sectional view of a tool rest, FIG. 2 is a sectional view of a rotary indexing device, and FIG. 3 is a sectional view of a lock mechanism portion of the rotary indexing device.

In the figure, reference numeral 1 denotes a tool rest mounted on an NC lathe. The tool rest 1 is not shown, but with respect to a main shaft fixed on a bed, the main shaft is in the axial direction and the shaft. It is arranged so as to be movable in a right angle direction, and is configured to process a workpiece mounted on the spindle.

The tool rest 1 includes a turret head 4 rotatably and axially movably supported by a tool rest main body 2, and a plurality of turret heads 4 mounted on the outer periphery of the turret head 4 at a predetermined angular interval. The tool holder 3 and the turret head 4 are rotationally indexed so that the required tool holder 3 is located at a predetermined machining position A, and a rotary indexing mechanism 5 for clamping the tool holder 3 at the machining position A and the tool rest body 2 are provided. It has an output shaft 9 which is non-rotatably supported so as to be movable in the axial direction together with the turret head 4, and engageably and disengageably engages with an input shaft 8 of the rotary tool T of the tool holder 3 indexed to the processing position A. Milling unit 6 and output shaft 9
And a rotary tool drive mechanism 7 for rotationally driving.

The turret head 4 comprises a turret head body 10 having a hollow portion 10a and having a substantially disk shape, and a turret cylinder portion 11 fixed to the turret head body 10 by bolts. It is supported by the tool rest main body 2 so as to be rotatable and axially movable. A holder mounting hole 10b for mounting each of the tool holders 3 is provided on the outer peripheral portion of the turret head body 10.
Are formed.

The milling unit 6 is arranged in the hollow portion 10a of the turret head body 10, and has a gear case 14 for rotatably supporting the turret head body 10 via bearings 16 and 17, and the gear case 14. And a milling tube portion 15 that is bolted and fixed to the turret tube portion 11. The milling tube portion 15 is inserted into the turret tube portion 11 so as to be coaxial therewith. This milling cylinder 1
5, a detent nut 16 fixed to the tool rest body 2 is spline-fitted to the rear end portion 15a of the tool rest 5, whereby the milling unit 6 is supported by the tool rest body 2 so as to be axially movable and non-rotatable. Has been done.

A rotary drive shaft 20 is coaxially inserted in the milling unit 6. A front end portion 20a of the rotary drive shaft 20 is supported by the gear case 14 via a bearing 21, and a rear end portion 20b is rotatably supported by the tool rest body 2 via a fitting cylinder 27 as described later. ing.

The output shaft 9 is arranged in the gear case 14 so as to form a right angle with the rotary drive shaft 20, and is supported by the gear case 14 via bearings 22, 22. A bevel gear 25 is integrally formed at the inner end of the output shaft 9, and the bevel gear 25 is spline-coupled to the front end 20a of the rotary drive shaft 20.
Are in mesh. The bevel gear 24 is supported by the gear case 14 via a bearing 23.

In the rotary tool drive mechanism 7, the rear end portion 20b of the rotary drive shaft 20 is axially accommodated in the fitting cylinder 27 rotatably supported by the tool rest main body 2 via bearings 26, 26. A structure in which a spline is movably and rotates together, a pulley 28 is fixed to the rear end of the fitting cylinder 27, and a servo motor is connected to the pulley 28 via a drive belt (not shown). Has become.

The input shaft 8 of each tool holder 3 is arranged at a right angle to the rotary drive shaft 20 and is arranged so as to be coaxial with the output shaft 9 when it is located at the processing position A. The input shaft 8 of the tool holder 3 indexed to the position A is disengageably engaged with the output shaft 9 via the clutch portion. The clutch portion has a structure in which a concave portion 9a extending in the radial direction is formed on the outer end portion of the output shaft 9 and a convex portion 8a that engages with the concave portion 9a is formed on the inner end portion of each input shaft 8. There is.

Here, in the rotary tool driving mechanism 7, as shown in FIG. 2, the rotary drive shaft 20 is arranged so that the concave portion 9a is always oriented in the direction perpendicular to the paper surface (the rotating direction of the turret head). Stop.

An annular guide portion 30 is arranged on the outer peripheral portion of the gear case 14 and is fixed by bolting. A guide groove 30a extending in the circumferential direction is formed on the outer peripheral portion of the guide portion 30 so as to be continuous with the concave portion 9a of the output shaft 9, and the guide groove 30a is provided with a tool holder 3 located at a position other than the machining position A. The convex portion 8a of each input shaft 8 is engaged. A cutout portion is formed in a portion of the guide portion 30 corresponding to the output shaft 9.

With this structure, when any one of the tool holders 3 is indexed at the machining position A, the tool holder 3 is indexed.
The convex portion 8a of the input shaft 8 is automatically engaged with the concave portion 9a of the output shaft 9. Further, when the input shaft 8 is disengaged from the processing position A, the engagement is released.

The rotary indexing mechanism 5 is an indexing drive section 5a for rotating the turret head 4 to a predetermined angular position.
And a clamp portion 5b for clamping the turret head 4 at the angular position.

The indexing drive section 5a is provided with a drive gear 37 of a drive motor 38 via an indexing gear 33 fixed to the turret cylinder 11 via first and second intermediate gears 35 and 36 mounted on an intermediate shaft 34. It has a connected structure.

The clamp portion 5b is an annular movable coupling 40 fixed to the turret head body 10 of the turret head 4 so as to rotate together, and a tool rest so as to face the movable coupling 40 so as to be meshable therewith. An annular fixed coupling 41 fixed to the main body 2 is provided.

A cylinder portion 2a is provided as a recess on the inner peripheral surface of the central portion of the tool rest body 2 in the axial direction.
An annular piston 42, which is fitted and fixed to the outer peripheral surface of the turret cylinder portion 11, is inserted into the inside of a so as to be axially movable. A clamp oil chamber a and an unclamp oil chamber b are formed by the piston 42 and the cylinder portion 2a. Further, the tool rest main body 2 is provided with a clamp hydraulic pressure supply port 2b communicating with the clamp oil chamber a and an unclamp hydraulic pressure supply port 2c communicating with the unclamp oil chamber b, and the respective supply ports 2b, 2c are provided. Are connected to independent hydraulic circuits.

When a hydraulic pressure is supplied from the clamp hydraulic pressure supply port 2b to the clamp hydraulic chamber a, the piston 42 moves rearward (to the right in the drawing), the turret head 4 moves accordingly, and the movable coupling 40 moves. It meshes with the fixed coupling 41. In this case, as the turret head 4 moves, the milling unit 6 and the rotary drive shaft 20 also move integrally. When the hydraulic pressure in the clamp oil chamber a is released and the hydraulic pressure is supplied from the unclamp hydraulic pressure supply port 2c to the unclamp hydraulic chamber b, the piston 42 moves forward (to the left in the drawing), and along with this, the turret head. 4 moves, and the engagement between the couplings 40 and 41 is released.

In the tool rest 1 of the present embodiment, the turret head 4 and the milling unit 6 are arranged so that the input shaft 8 and the output shaft 9 indexed to the processing position A coincide with each other. Lock mechanism 45 for positioning and fixing
It is provided in pairs.

The lock mechanism 45 has three cylinder holes 46 formed in the turret head body 10 at predetermined angular intervals in the circumferential direction so as to face the inside of the hollow portion 10a, and a fitting position in each of the cylinder holes 46. A positioning pin 47 that is inserted so as to be retractable between a release position for releasing the fitting and a conical fitting hole formed in a portion of the gear case 14 corresponding to the processing position A of each tool holder 3. And 48.

The positioning pin 47 has a piston portion 4 having a diameter larger than the rear end of the pin portion 47a having a conical tip.
7b is formed, and the piston portion 47
The outer peripheral surface of b is in oil-tight contact with the inner peripheral surface of the cylinder hole 46. Further, the piston portion 47b and the cylinder hole 46 are
A spring 49 for urging the positioning pin 47 in the releasing direction is provided between the stepping portion 46a formed in the opening of the spring and the stepped portion 46a.

A lock oil chamber c is formed by the bottom portion 46b of the cylinder hole 46 and the piston portion 47b. An oil passage 11a formed in the turret cylinder 11 is connected to the lock oil chamber c, and the oil passage 11a is connected to a lock hydraulic pressure supply port via an oil supply passage 2d formed in the tool rest main body 2. 2e is connected for communication.

A hydraulic circuit connected to the clamp hydraulic pressure supply port 2b is shared by the lock hydraulic pressure supply port 2e so that the hydraulic pressure is supplied to the lock oil chamber c at the same time as the clamp oil chamber a. Has become.

Next, the function and effect of this embodiment will be described.

During normal work machining, by engaging the movable coupling 40 with the fixed coupling 41,
The tool holder 3 is clamped at the processing position A. Further, by fitting the positioning pin 47 into the fitting hole 48, the milling unit 6 is positioned and fixed to the turret head 4. In this state, the rotary tool drive mechanism 7 rotationally drives the rotary tool T by the input shaft 8 via the rotary drive shaft 20 and the output shaft 9, and a predetermined milling process is performed.

When the machining is completed and the next workpiece is machined, the turret head 4 is indexed so that the tool holder for the next machining is positioned at the machining position A. In this case, the hydraulic pressure in the clamp oil chamber a is released first, and the hydraulic pressure in the lock oil chamber c is released accordingly. As a result, the positioning pin 47 is retracted to the fitting release position in the cylinder hole 46 by the urging force of the spring 49, and the positioning of the milling unit 6 is released. Subsequently, hydraulic pressure is supplied to the ank clamp oil chamber b, the turret head 4 moves forward, the engagement between the two couplings 40 and 41 is released, and then the indexing drive unit 5a rotationally drives the indexing gear 33. Thereby, the turret head 4 is rotated.

When the tool holder for the next machining is indexed to the machining position A, the hydraulic pressure in the unclamping oil chamber b is released and the hydraulic pressure is supplied to the clamping oil chamber a, and the turret head 4 moves. Both couplings 40 and 41 mesh. On the other hand, as the hydraulic pressure is supplied to the clamp hydraulic chamber a, the hydraulic pressure is also supplied to the lock hydraulic chamber c, the positioning pin 47 is pushed out and fitted into the fitting hole 48 of the gear case 14, and the milling unit 6 moves the turret. The head 4 is positioned and fixed. In this case, the pin portion 47a of the positioning pin 47
Since the fitting hole 48 and the fitting hole 48 are formed in a conical shape, even if there is a deviation between the milling unit 6 and the turret head 4, this can be corrected, and the tool holder for the next processing is processed in this way. When the milling unit 6 is clamped at the position A, the milling unit 6 is accurately positioned on this, and the output shaft 9 and the input shaft 8 are connected with their axes aligned.

Since the milling unit 6 is positioned and fixed on the turret head 4 clamped on the tool rest main body 2 in this manner, the input shaft 8 indexed to the machining position A is obtained.
The output shaft 9 and the output shaft 9 can be made to coincide with each other, and there is no problem that the milling unit 6 is displaced with respect to the turret head 4 during the milling process, so that clutch error, heat generation, and noise generation can be prevented.

According to the lock mechanism 45 of the present embodiment, the position where the positioning pin 47 is fitted in the fitting hole 48 formed in the milling unit 6 in the cylinder hole 46 formed in the turret head 4, Since the positioning pin 47 is arranged to be retractable between the release position and the cylinder hole 46, and the positioning pin 47 is actuated by the hydraulic pressure for clamping, it is possible to use a link type link pin composed of a plurality of conventional pins and levers. The structure can be simpler than that of the conventional one, the number of parts can be reduced, and a lock mechanism that is low in cost and hard to break down can be configured.

Further, in the present embodiment, it is only necessary to secure a space for forming the cylinder hole 46 in which the positioning pin 47 can be accommodated in the turret head 4, so that the space can be saved. As a result, a plurality of lock mechanisms 45 can be arranged in the circumferential direction, and stable positioning can be performed.

In the present embodiment, the lock hydraulic pressure for driving the positioning pin 47 is shared with the clamp hydraulic circuit,
Since the positioning pin 47 is operated in conjunction with the clamp operation of the turret head 4, the positioning hydraulic pin circuit can be effectively utilized to drive the positioning pin 47, which can further simplify the structure and improve the responsiveness of the positioning pin. Can be improved.

[Brief description of drawings]

FIG. 1 is a schematic sectional view for explaining a tool rest of a machine tool according to an embodiment of the present invention.

FIG. 2 is a sectional view of a rotary indexing mechanism portion of the tool post.

FIG. 3 is a cross-sectional view of a lock mechanism portion of the tool post.

FIG. 4 is a cross-sectional view of a conventional lock mechanism.

[Explanation of symbols]

1 Turret 2 turret body 3 Tool holder 4 turret head 5 rotation indexing mechanism 6 milling units 7 Rotary tool drive mechanism 8 input axes 9 Output shaft 45 Lock mechanism 47 Positioning pin A processing position T rotary tool

Claims (2)

[Claims] 1. A turret head, which is rotatably and axially movably supported by a tool rest body, and on which a plurality of tool holders are mounted at predetermined angular intervals in the circumferential direction, and the turret head having the above-mentioned required features. The tool holder is rotationally indexed so as to be located at a predetermined machining position, and the rotary indexing mechanism for clamping the tool holder at the machining position is supported by the tool rest main body so as not to be rotatable and axially movable together with the turret head. A tool post of a machine tool including a milling unit having an output shaft releasably engaged with an input shaft of a rotary tool of a tool holder indexed to a position, and a rotary tool drive mechanism for rotationally driving the output shaft. In the above, the turret head and the milling unit are positioned and fixed so that the input shaft and the output shaft indexed to the machining position are aligned with each other. A locking mechanism for fixing the locking mechanism, and the locking mechanism is disposed so as to be retractable between a fitting position where the positioning pin is fitted to the turret head and a releasing position where the fitting is released, A tool rest of a machine tool, wherein the positioning pin is configured to be operated by fluid pressure. 2. The fluid pressure according to claim 1, wherein a hydraulic pressure for clamping that clamps the turret head is commonly used, and the positioning pin is operated in conjunction with a clamping operation by the hydraulic pressure for clamping. A tool post of a machine tool characterized by being used.