JPS6336899B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an automatic tool changer for a machine tool,
In particular, the present invention relates to a new automatic tool changer (hereinafter referred to as an ATC device) that indexes and rotates a tool magazine for tool storage using the rotation of the main shaft of a machine tool.

Various mechanisms are available for starting the indexing rotation of the tool magazine in the ATC device of a machine tool, and the indexing rotation of the tool magazine is started using the reciprocating motion in the axial direction of the machine tool's main spindle. ATC devices are also available. However, there is a continuing need to achieve automatic tool change more quickly to reduce tool change time and improve machine tool operating efficiency.

SUMMARY OF THE INVENTION Therefore, it is an object of the present invention to provide an ATC device for a machine tool that can meet these demands and is compactly formed.

That is, according to the present invention, a spindle head of a machine tool having a spindle rotationally driven by a spindle motor and capable of moving linearly between a machining area and a tool changing area;
An automatic tool changer for a machine tool comprising a rotary tool magazine that is non-fixedly held on the spindle head and moves linearly between the machining area and the tool exchange area. a stopper that is stationary with respect to the tool spindle at a fixed position for attachment and detachment, and that enables attachment and detachment of the tool by moving the spindle head with respect to the fixed position for attachment and detachment; A driven gear for tool indexing that can engage and disengage from a gear mounted on the main shaft in response to the main shaft head reaching or leaving a fixed position for use, and a driven gear for tool indexing that engages with the main shaft and detects its rotation angle. By doing so, the system includes a position coder that detects the engagement position of the gear of the main shaft with respect to the driven gear for tool indexing of the tool magazine and the indexing rotational position of the tool magazine. An ATC device for a machine tool is provided, characterized in that tool exchange is performed between the main spindle and a tool magazine by linear movement and rotation of the main spindle. Hereinafter, the present invention will be described in detail based on embodiments shown in the accompanying drawings.

Fig. 1 is a schematic mechanical diagram showing the overall machine of a numerically controlled machine tool equipped with an embodiment of the ATC device according to the present invention, and Fig. 2 shows the machine tool spindle and tool magazine during tool exchange in the ATC device. It is a schematic mechanical diagram showing the relative positional relationship of the

In Fig. 1, the spindle head 10 of the machine tool is oriented upwardly and downwardly (Z
The vertical main shaft 12 is rotatably supported inside via bearing means. Below this spindle head 10, a work table 16 is mounted on a fixed base 14 of the machine tool so as to be slidable in two perpendicular axes directions (X-axis direction and Y-axis direction) within a horizontal plane perpendicular to the Z-axis. The workpiece W is mounted on the worktable 16.
In the NC machine tool, the above-mentioned movement of the spindle head 10 in the Z-axis direction, rotation of the spindle 12, and movement of the work table 16 in the The movement of the spindle head 10 in the Z-axis direction is controlled by a servo motor controlled by a command signal NCZ of the NC device 18. a Z-axis feed motor 20, a Z-axis feed screw 24 which is rotated by the Z-axis feed motor 20 via an appropriate speed reduction mechanism 22, and a nut provided on the spindle head 10 and engaged with the Z-axis feed screw 24. 26, and the spindle head 10 is moved in the Z-axis direction along the aforementioned column. The rotation of the main shaft 12 is controlled by a command signal from the NC device 18.
It is operated by a main shaft rotation actuating means consisting of a main shaft motor 28 which is a servo motor controlled by the NCS, and a belt pulley mechanism 30 provided between the output shaft of this main shaft motor 28 and the main shaft 12. The rotational speed of the main shaft 12 is determined by a rotational speed signal from a tachometer 32 consisting of a tacho generator.
By sending the SV to the NC device 18, the spindle 1
The rotational speed of No. 2 is controlled to a required machining speed. Furthermore, the movement of the work table 16 in the X-axis direction and the Y-axis direction is controlled by the NC device 1.
X-axis feed motors 34 and Y consisting of servo motors controlled by command signals NCX and NCY from
The shaft feed motor 36 and these feed motors 34,
an X-axis feed screw 38 rotatably operated by 36;
The X-axis feed actuating means and the Y-axis feed actuating means formed by the Y-axis feed screw 40 are respectively actuated. Further, the rotational angular position of the main shaft 12 is determined by a well-known position coder 4 via a precise angle transmission means 42 consisting of a timing belt and a toothed pulley.
4, and this detection signal SP is also sent to the NC device 18, so this detection signal SP is
The main shaft 12 rotated by the main shaft motor 28 can be positioned at a desired rotation angle position with respect to the machine body by detection by the NC device 18. Reference numeral 46 denotes an arm or bracket that is fixedly formed integrally with the above-mentioned spindle head 10, and a spring 48 is stretched between this bracket 46 and a slider 70 of an ATC device that will be described later. 50 is a part of the machine body 52
This is a stopper attached to the slider 70, and is provided at a position facing the slider 70 as described later.

Now, the automatic tool changer (ATC) device 60 according to the present invention has a tool magazine 62, and this tool magazine 62 has a magazine body 6 having a truncated pyramid shape.
4, and a plurality of tool storage holes for storing a plurality _of tools T ₁ . The magazine body 64 is fixed to a magazine cylinder 66, which has rotation bearing means (not shown) therein and is rotatably supported around an oblique shaft 68. When the magazine main body 64 rotates, the plurality of storage holes are configured to pass directly under the main shaft 12 one after another. On the other hand, the upper end of the oblique shaft 68 is fixed to the approximate center of the slider 70, and the slider 70 slides upward and downward between the upper and lower guide portions 54 formed on one side of the spindle head 10. It has sliding parts 72, 72 so as to be movable. Further, the lower end of the spring 48 described above is fixed to the upper end of the slider 70, and the upper end of this spring 48 is fixed to the bracket 46. In the illustrated state, a constant spring tension is maintained, that is, the ATC device 60 is pulled up toward the upper end portion of the bracket 46 via the slider 70. In the state shown in FIG. 1, the storage hole containing one tool T ₁ of the plurality of tools T ₁ ......T _o stored in the magazine body 64 of the ATC device 60 is the tool spindle 1.
The tool T1 is aligned upwardly and downwardly with a tool receiving hole (not shown) formed at the lower end of the tool T1, and the tool _T1 is installed in the tool receiving hole, and this position (hereinafter referred to as the Z-axis origin position) The spindle head 10 descends toward the workpiece W, and the spindle head 10 moves down toward the workpiece W by the operation of the spindle motor 28.
When it rotates, the workpiece W can be machined. It is well known that each of _the tools T ₁ . Now, a bevel gear 74 is fixedly arranged at the upper end of the magazine barrel 66 of the tool magazine 62 concentrically with the diagonal shaft 68, while a bevel gear 58 that rotates integrally with the main shaft 12 is attached to the lower end of the spindle head 10. ing. These double bevel gears 7
4 and 58 have teeth of the same module so that they can mesh with each other, for example, in the case of involute teeth, but the bevel gear 74 on the tool magazine 62 side is connected to the spindle head 10 so that a constant deceleration rate can be obtained. It is formed to have a larger diameter than the bevel gear 58 on the side, and thus a larger gear. When the spindle head 10 and the ATC device 60 are located at the Z-axis origin position shown in FIG. Therefore, the ATC device 60 is in an inactive state.

Next, an automatic tool exchange operation in which the ATC device 60 operates to exchange the tool T ₁ mounted on the spindle 12 of the spindle head 10 with another tool will be described below.

When exchanging tools, first, the spindle head 10 and the tool magazine 62 are moved by the Z-axis feed motor 20 from the machining area for the workpiece W to the above-mentioned constant Z-axis origin position.
It returns to the upward position by the operation of . Also, during this upward return operation, the main shaft 12 of the main shaft head 10 is rotated by the operation of the main shaft motor 28, so that the bevel gear 58 is integrally rotated, and the rotation angle of the main shaft 12 is also controlled by the position coder 44. Due to the detected position, the main shaft 12 and therefore the bevel gear 5
A so-called orientation operation is performed to position 8 at a constant rotational angle position. At a certain rotation angle position determined by this orientation operation, a preselected tooth of the bevel gear 58 comes to a phase position where it can mesh with a tooth of the bevel gear 74 of the tool magazine 62 and stops. On the other hand, in the bevel gear 74 of the tool magazine 62, any tool storage hole in the magazine body 64 is connected to the main shaft 12.
When the teeth of the bevel gear 74 are aligned with the tool receiving hole of the spindle head 10, the teeth of the bevel gear 74 are always in the same phase. A number has been designed and assembled. For this reason, there is always a difference between the number of tool storage holes (N) provided in the magazine body 64 and the number of teeth (M) of the bevel gear 74.
The following relationship has been established: I×N, I...integer. As a result, when the above-described orientation operation positions the selected tooth on the bevel gear 58 of the spindle head 10, particularly the tooth peak, to a phase position that correctly aligns with the tooth trough of the bevel gear 74, This enables smooth meshing and engagement in response to the relative approaching motion of both gears 58 and 74, which will be described later. When the orientation operation of the main shaft 12 and bevel gear 58 of the main spindle head 10 is completed as described above, the main spindle head 10 is moved upward from the Z-axis origin position by the operation of the Z-axis feed actuating means having the Z-axis feed motor 20. It is operated upward in the tool change area (ATC area). At this time, since the ATC device 60 is pulled up toward the bracket 46 via the slider 70 by the tension of the spring 48 as described above, the tool magazine 62 is also pulled up along with the spindle head 10.
Ascend the ATC area as one. During this upward movement, the tight fit between the main shaft 12 and the tool _T1 attached to its lower end is released by means of a known appropriate means such as a cam means not shown in FIG.
Next, when the upper end of the slider 70 in the ATC device 60 rises to a position where it comes into contact with the stopper 50, only the raising of the tool magazine 62 is stopped, and the sliding parts 72, 72 of the slider 70 and the upper and lower guide parts 54 of the spindle head 10 Due to the above-described sliding structure formed by the above, only the spindle head 10 continues to move upward while increasing the tension of the spring 48. As a result, at the lower end of the spindle 12, the tool T ₁ is
2, and is left in the storage hole of the magazine body 64. Then, as shown in FIG. 2, when the tool T ₁ is completely removed from the tool receiving hole of the tool spindle 12, the bevel gear 58 meshes with the bevel gear 74 of the tool magazine 62. When both gears 58 and 74 mesh, the Z-axis feed operation means stops operating.
Next, the main shaft motor 28 is operated in accordance with the command signal NCR of the NC device 18, and when the main shaft 12 and the bevel gear 58 are rotated by a desired amount via the belt pulley mechanism 30, this rotation is caused by the bevel gear 74.
The tool magazine 62 is also rotated by a desired amount, and then the spindle 1
A tool to be mounted on the main shaft 12, for example, a tool _T3 , is indexed directly below the tool receiving hole of the main spindle 12. That is,
Since the tool change order is programmed in advance in the NC device 18, a command signal NCR according to this program is applied to the spindle motor 28, and the spindle 1
By controlling the amount of rotational operation of the tool magazine 62, indexing rotation of the tool magazine 62 is caused by the rotation transmission means consisting of the bevel gears 58 and 74. Moreover, the rotation angle position of the main shaft 12 is
An angle transmission means 4 consisting of a timing belt mechanism
2, the tool magazine 6 is detected by the position coder 44 engaged through the tool magazine 6.
The indexing rotation amount of T 2 is also controlled extremely accurately and precisely, and the new tool T ₃ is indexed to a position where the tool receiving hole of the main spindle 12 is accurately aligned in the axial direction.

When a new tool _T3 is indexed as described above, the operation of the spindle motor 28 is stopped and the NC is started again.
The Z-axis feed motor 20 is actuated by the command signal NCZ from the device 18, and the spindle head 10 is moved downward toward the Z-axis origin position by the operation of the Z-axis feed actuation means. When the arbor 56 of the new tool T ₃ is fitted into the tool receiving hole of the spindle 12, the new tool T ₃ is moved to the spindle 1 by the operation of appropriate means such as the cam means described above.
2 is tightly fitted and tightened. During this time, in response to the descent of the spindle head 10, only the spindle head 10 is lowered independently until the tension of the spring 48 is relaxed to a constant force, so that the bevel gear 5
8 and 74 are disengaged. When the tension of the spring 48 is relaxed to a certain level, the spindle head 10 and the ATC device 60
The tool magazines 62 are lowered together, and when both reach the Z-axis home position, the Z-axis feed motor 2
0, the lowering is stopped and the automatic tool change operation is completed. When the automatic tool change operation is completed, the spindle head 10 moves down the machining area toward the workpiece W under the control of the NC device 18 and replaces the new tool.
Machining is done using _T3 .

As is clear from the above description, according to the present invention, the indexing rotation of the tool magazine 62 in the ATC device 60 utilizes the rotation of the main shaft 12, that is, the tool magazine 62 is
Furthermore, since the position coder 44 engaged with the main shaft 12 detects the amount of indexing rotation, extremely accurate and precise, yet rapid indexing rotation is achieved. This makes it possible to significantly improve the reliability and efficiency of automatic tool change operations. Moreover, since the rotation transmission means described above is constituted by a pair of gear mechanisms, the structure of the ATC device 60 disposed close to the spindle head 10 can also be made compact.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing the overall mechanism of a numerically controlled machine tool equipped with an automatic tool changer according to an embodiment of the present invention, and Fig. 2 is a machine tool main shaft during tool change in the automatic tool changer. FIG. 3 is a schematic mechanical diagram showing the relative positional relationship between and the tool magazine. 10...Spindle head, 12...Spindle, 16...Work table, 18...NC control device, 20...Z
Axis feed motor, 28...Main shaft motor, 34...X
Axis feed motor, 36... Y-axis feed motor, 44...
...Position coder, 60...ATC device, 62
...Tool magazine, 58,74...Bevel gear,
T ₁ ......T _o ...Tool.

Claims (1)

[Scope of Claims] 1. A spindle head of a machine tool having a spindle rotationally driven by a spindle motor and capable of moving linearly between a machining area and a tool changing area; In an automatic tool changer for a machine tool, the tool magazine is stationary relative to the spindle at a predetermined position for attaching and removing tools in the tool change area. a stopper that enables the tool to be attached and detached by moving the spindle head relative to the fixed position for attaching and detaching the tool; and a stopper that is attached to the tool magazine so that the spindle head reaches and leaves the fixed position for tool indexing in the tool changing area. a driven gear for tool indexing that can be engaged with and disengaged from the gear mounted on the main shaft according to the operation;
A position that detects the engagement position of the gear of the main shaft with respect to the driven gear for tool indexing of the tool magazine and the indexing rotational position of the tool magazine by engaging the main shaft and detecting its rotation angle. 1. An automatic tool changer for a machine tool, comprising: a coder, and is configured to change tools between the spindle and a tool magazine by linear movement of the spindle head and rotation of the spindle. 2. Claim 1, wherein the main shaft drive motor and the position coder engaged with the main shaft are coupled to a numerical control device and controlled by the numerical control device.
An automatic tool changer for a machine tool described in .