JP3379145B2 - Machine tools using automatic tool changers - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses an automatic tool changer which is capable of changing a tool between a spindle and a tool magazine having different mounting hole diameters. It relates to machine tools. 2. Description of the Related Art As a conventional machine tool using an automatic tool changer, for example, as disclosed in Japanese Patent Application Laid-Open No. 61-257737, a sub-tool magazine for storing small-diameter tools, a large-diameter tool and a mother A main tool magazine for storing tools,
A main spindle that moves vertically and horizontally to detachably mount a large-diameter tool or a mother tool, a small-diameter tool exchange device that exchanges small-diameter tools between the sub tool magazine and the mother tool of the main tool magazine, and a main tool magazine. Some machines are provided with a spindle tool exchange device for exchanging a large diameter tool or a mother tool between spindles. [0003] As the large-diameter tool, a cup-type milling machine,
There are a drill, an end mill, and the like, and the small-diameter tool includes a small-diameter whetstone, a drill, an end mill, and the like. Preferably, the cup-type milling machine is rotated at a low speed, and the small-diameter grindstone is rotated at a high speed. The main shaft is rotatably supported via a rolling bearing.Because the rolling bearing thermally expands due to the rotation of the main shaft, the preload of the rolling bearing must be set in accordance with low speed rotation or high speed rotation. It is difficult to make the speed correspond widely. Therefore, there has been a problem that sufficient processing accuracy cannot be obtained at low speed rotation or high speed rotation. [0004] In order to solve such a problem, a high-speed spindle capable of rotating at a high speed with a small outer diameter, and increasing the outer diameter to increase the processing rigidity. The low-speed spindle is prepared separately, and the small-diameter tool is exchanged between the tool magazine and the high-speed spindle using the small-diameter tool changer.
It is conceivable to exchange a large-diameter tool between the tool magazine and the low-speed spindle using a large-diameter tool exchange device. However, in such a device, a small-diameter tool changing device for gripping a small-diameter gripped portion of a small-diameter tool,
If a large-diameter tool changer for gripping a large-diameter gripped portion of a large-diameter tool is prepared, there is a problem that the structure becomes complicated and expensive. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has a high-speed rotating spindle for a small-diameter tool on which a small-diameter tool is mounted, and a large-diameter tool mounted thereon. A low-speed rotating spindle for large-diameter tools is prepared, and a transfer device for selectively indexing the automatic tool changer to a position where tool exchange can be performed with the spindle for small-diameter tools or the spindle for large-diameter tools is provided.
The outer diameter of the part to be gripped by the automatic tool changing device for the small-diameter tool so that the tool can be changed by the common automatic tool changing device between the main spindle for the small-diameter tool or the main spindle for the large-diameter tool and the tool magazine. The outer diameter of the gripped portion gripped by the automatic tool changer for the large diameter tool is the same. The automatic tool changer is indexed by the transfer device to a position where the tool can be exchanged with the main spindle for the small diameter tool or the main spindle for the large diameter tool. Tool exchange of a small diameter tool or a large diameter tool is performed between the main spindle and the tool magazine. An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, reference numeral 10 denotes a bed, and pillars 11 are erected at four corners of the bed 10, and a top plate 12 is fixed to an upper end of the pillar 11. A tool magazine 20 is fixed to the upper surface of the top plate 12. The tool magazine 20 includes a rotating motor 21, a rotating plate 22 rotated in a vertical plane by the rotating motor 21, and a rotating plate 22 as shown in FIG. 2. Sockets 23a and 23b provided at equal circumferential intervals. The socket 23a is formed with a small-diameter mounting hole 24a and includes a ball 25a that engages with the pull stud 31a of the small-diameter tool 30a. The ball 25a is urged by a spring 26a. Similarly, socket 23b
Is formed with a large-diameter mounting hole 24b and has a ball 25b that engages with the pull stud 31b of the large-diameter tool 30b. The ball 25b is urged by a spring 26b. The small-diameter tool 30a has a small-diameter tapered shank portion 32a mounted in the mounting hole 24a, and a gripped portion 33 having a concave cross section gripped by an exchange arm 41 described later.
a and a processing unit 34a for processing a work. Similarly, the large-diameter tool 30b includes a large-diameter tapered shank portion 32b to be mounted in the mounting hole 24b and an exchange arm 4 to be described later.
A gripped portion 33b that is gripped by the first and has a concave cross section and a processing portion 34b that processes a work are provided. The small diameter tool 30
a to be gripped portion 33a and gripped portion 33b of large-diameter tool 30b
Are formed to have the same diameter so as to be gripped by the same automatic tool changer 40 described later. An automatic tool changer 40 is mounted on the lower surface of the top plate 12, and includes an exchange arm 41 that rotates around a horizontal axis.
At both ends of 1, there are provided gripping portions 42 for detachably gripping the gripped portion 33a of the small-diameter tool 30a or the gripped portion 33b of the large-diameter tool 30b. As shown in FIG. 3, each of the gripping portions 42 has a fixed engaging portion 42a having a convex cross section and an arc shape that engages with the gripped portions 33a and 33b, and a gripped portion 33a that prevents the tools 30a and 30b from coming off. , 33b to be engaged with the gripped portion 3b.
It is urged by a spring 42c in a direction to engage with 3a, 33b. The exchange arm 41 is turned 90 degrees from a horizontal state by a drive source 43, forwardly moved, turned 180 degrees,
The reverse and the 90-degree turning in the opposite direction are continuously performed,
When the movable engagement portion 42b is retracted by the degree rotation and the movable engagement portion 42b is advanced by the spring 42c, the gripped portion 33a of the small-diameter tool 30a or the large-diameter tool 30
b is mechanically gripped, the movable engaging portion 42b is retracted by the tool by the 90-degree turning in the opposite direction, and the movable engaging portion 42b is advanced by the spring 42c, thereby causing the small-diameter tool 30a to move forward. Gripped part 33a
Alternatively, the gripping of the gripped portion 33b of the large-diameter tool 30b is mechanically released. A guide table 50 is provided on the bed 10, and a table 51 is guided by the guide table 50 so as to be movable in a horizontal direction orthogonal to the rotation axis of the exchange arm 41. A servo motor 15 is attached to the guide table 50, and the table 51 is moved in the left-right direction in FIG. 1 via a ball screw (not shown). A transfer device for moving the table 51 by the servo motor 15 and the ball screw is configured. On the table 51, there is a headstock 5
As shown in FIG. 4, a spindle 53 for a small-diameter tool and a spindle 54 for a large-diameter tool are respectively mounted on the headstock 52 so as to be rotatable around an axis parallel to the turning axis of the exchange arm 41. Have been. The spindle 53 is for high-speed rotation, has a small spindle outer diameter, and has a small-diameter mounting hole 53a formed at the tip of the spindle for detachably holding the small-diameter tool 30a. The spindle 54 is for low-speed rotation, has a large spindle outer diameter, and has a large-diameter mounting hole 54a formed at the tip of the spindle so as to detachably hold the large-diameter tool 30b. The spindle 53,
Numeral 54 is adapted to be rotationally driven by respective built-in motors 55, 56 built in the headstock 52, and mounting holes 53a,
Collet chico-jack type gripping devices 57, 58 for gripping the pull studs 31a, 31b of the tools 30a, 30b mounted on the 54a are provided. The operation of the tool magazine 20, the automatic tool changer 40 and the table 51 is controlled by a numerical controller. Next, the operation will be described based on the configuration described above. When a small-diameter tool change command is issued from the numerical controller, the rotary plate 22 of the tool magazine 20 is rotated, and the next tool to be used is indexed to a position where it can be gripped by the change arm 41. Further, the table 51 is moved, and the small-diameter tool 30a of the main shaft 53 is indexed to a position where the small-diameter tool 30a can be gripped by the exchange arm 41. Subsequently, the exchange arm 41 rotates 90 degrees, the gripped portion 33a of the small-diameter tool 30a of the tool magazine 20 is mechanically gripped by one gripper 42, and the small-diameter tool 30 of the spindle 53 is gripped by the other gripper 42.
The gripped portion 33a of “a” is mechanically gripped. In this state, the grasping of the pull stud 31a by the grasping device 57 of the main shaft 53 is released, and the exchange arm 41 is advanced. As a result, the grip of the small tool 30a to be used next by the ball 25a is automatically released and the socket 23a
And the small-diameter tool 30a is extracted from the main shaft 53. next,
The exchange arm 41 is rotated by 180 degrees, the exchange arm 41 is retracted, and the next small-diameter tool 30a to be used next is mounted in the mounting hole 53a of the main shaft 53, and the used small-diameter tool 30a is
Into the mounting hole 24a of the socket 23a. At this time, the used small-diameter tool 30a is automatically gripped by the ball 24a. Subsequently, the next small-diameter tool 30
The pull stud 31a is gripped by the gripping device 57 of the main shaft 53, the exchange arm 41 is turned by 90 degrees in the opposite direction, and the small-diameter tool 30a is gripped by the grip portion 42 of the exchange arm 41.
Is mechanically released from the gripped portion 33a. continue,
The work of the workpiece is performed by rotating the main shaft 53 and moving the table 51. At this time, the spindle 54 on the side of the large-diameter tool 30b is idle, and the work is not processed. The replacement of the large-diameter tool 30b is performed in the same manner as in the case of the small-diameter tool 30a. In this case, the large-diameter tool 30b of the main shaft 43 holds the table 51 by the exchange arm 41 according to the large-diameter tool exchange command of the numerical controller. Determine where possible. Thus, by providing the main shaft 53 for the small diameter tool and the main shaft 54 for the large diameter tool, by selecting and using the main shaft 53 for the small diameter tool and the main shaft 54 for the large diameter tool according to the main shaft rotation speed, Processing accuracy can be improved. That is, by rotating the small-diameter grindstone at a high speed using the small-diameter tool spindle 53, the machining accuracy can be improved, and the cup-type milling machine or the like can be rotated at a low speed using the large-diameter tool spindle 54 having a high processing rigidity. By doing so, the processing accuracy can be improved. Further, the gripped portion 33a of the small-diameter tool 30a and the gripped portion 30b of the large-diameter tool 30b have the same diameter and can be gripped by the common automatic tool changer 40, so that the structure is simplified and the cost is reduced. Machine tools can be provided.
In the above-described embodiment, the example has been described in which the table 51 is moved and the main shaft 53 for the small-diameter tool or the main shaft 54 for the large-diameter tool is located at a position where the tool can be changed by the automatic tool changer 40. 20 and the automatic tool changer 40 are moved, and the automatic tool changer 40 is
May be indexed to a position where the tool can be replaced with the small-diameter tool 30a or the large-diameter tool 30b of the main shaft 54. In addition, a tool magazine for small-diameter tools is provided at a position corresponding to the main shaft 53 for small-diameter tools, a tool magazine for large-diameter tools is provided at a position corresponding to the main shaft 54 for large-diameter tools, and the automatic tool changer 40 is provided. Tool magazine for small diameter tools and spindle 53 for small diameter tools or tool magazine for large diameter tools and spindle 5 for large diameter tools
A position at which the tool can be exchanged with the position 4 may be determined. As described above, according to the present invention, the grasped portion of the small-diameter tool and the grasped portion of the large-diameter tool have the same diameter .
The gripped portion of the small-diameter tool and the gripped portion of the large-diameter tool for low-speed rotation can be gripped. Therefore, the structure is simplified, and an effect that an inexpensive machine tool can be provided is obtained.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a machine tool using an automatic tool changer according to the present invention. FIG. 2 is a sectional view taken along the arrow A in FIG. FIG. 3 is a partial cross-sectional view of an exchange arm. FIG. 4 is a sectional view taken along line BB in FIG. 1; [Description of Signs] 10 Bed 15 Servo motor (transfer device) 20 Tool magazine 30a Small-diameter tool 30b Large-diameter tool 32a Shank portion 32b Shank portion 33a Grabbed portion 33b Grabbed portion 40 Automatic tool changer 51 Table 52 Headstock 53 Spindle 53a mounting hole 54 spindle 54a mounting hole

Claims (1)

(57) [Claim 1] A headstock provided with a rotating spindle and having a mounting hole at the tip of the spindle in which a tool is removably mounted, and a tool magazine for storing a plurality of tools. In a machine tool using an automatic tool changing device having an automatic tool changing device for performing a tool change between a spindle and a tool magazine, a small diameter tool having a mounting hole in which a small shank portion of a small diameter tool is mounted.
A high-speed rotating spindle and a low-speed rotating spindle for a large-diameter tool having a mounting hole into which a large-diameter shank portion of a large-diameter tool is mounted, respectively, and the automatic tool changing device is used for a spindle for a small-diameter tool or for a large-diameter tool. A transfer device is provided for selectively indexing the main spindle to a position where the tool can be changed, and the outer diameter of the gripped portion gripped by the automatic tool changing device for the small-diameter tool and the transfer device gripped by the automatic tool changing device for the large-diameter tool are provided. A machine tool using an automatic tool changer, wherein an outer diameter of a grip portion is made equal.