JP2852394B2 - Tool changer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool changer, and more particularly, to a tool changer that automatically changes a tool in a printed circuit board drilling machine or the like.

[Conventional technology]

2. Description of the Related Art Conventionally, a printed board drilling machine is provided with a tool changing device including a tool holding device for holding a plurality of types of tools, and a spindle having a tool mounting chuck disposed above the tool holding device. . As such a tool changing device, the tool holding device is raised using air pressure and stopped at a predetermined tool changing position, and then the spindle is lowered to the tool changing position, and the tool is moved between the tool holding device and the spindle. There has been proposed an automatic exchange.

[Problems to be solved by the invention]

However, in the above prior art, no consideration is given to the impact that occurs when the tool holding device is raised and stops at its operating end, and when the tool holding device is raised and the tool change position is stopped, However, there is a disadvantage that the tool is disengaged from the tool holding device due to an impact applied to the tool.

SUMMARY OF THE INVENTION An object of the present invention is to provide a tool changer capable of reliably performing a tool change by reducing a shock applied to a tool when the tool holder is stopped, thereby preventing a tool from coming off from the tool holder. It is to be.

[Means for solving the problem]

In order to achieve the above object, the present invention provides a reciprocating spindle having a tool mounting chuck, a tool holding unit for holding a plurality of types of tools, and a reciprocating movement of the tool holding unit with respect to the spindle. A driving unit for moving the tool holding unit to stop at a predetermined tool changing position, and then moving the spindle to the tool changing position to perform a tool change. Switching means is provided for switching the driving force of the drive unit when moving to the tool change position to a value smaller than the drive force for maintaining the tool holding unit in a stopped state during tool change.

[Action]

According to the above configuration, when the tool holding unit is moved to the tool changing position, the tool holding unit is moved at a low speed with a minimum driving force required to drive the tool holding unit. When the tool holder is stopped at the tool change position, which is the operating end, in which the tool holder is moved at a low speed, no impact is applied to the tool, and the tool can be prevented from coming off from the tool holder.

When the tool holding unit stops at the tool changing position, the spindle moves to the tool changing position, and the tool is changed between the tool holding unit and the spindle. In this case, since the tool holding unit is pressed by the spindle, the driving force of the drive unit needs to be large enough to maintain the stopped state of the tool holding unit in order to reliably perform the tool change. Therefore, the switching unit is operated to switch the driving force of the driving unit to a value larger than the minimum driving force required for driving the tool holding unit.

〔Example〕

 An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of a printed circuit board drilling machine to which the tool changer of the present invention is attached. In the figure, a guide 2 is fixed on a bed 1, and a table 3 is arranged on the guide 2. The table 3 can be reciprocated in the arrow X direction by a screw feed mechanism (not shown).

A column 4 is erected on both sides of the bed 1 so as to straddle the bed 1, and a guide 5 is fixed to an upper portion of the column 4. A slider 6 is mounted on the guide 5, and the slide 6 is screwed to a feed screw 7 by a nut (not shown). When the feed screw 7 is driven to rotate by the motor 8, the slider 6 reciprocates in the arrow Y direction. A saddle 9 is mounted on the slider 6, and the saddle 9 is reciprocated in an arrow Z direction by a motor 10 fixed to the slider 6.
A spindle 11 is fixed to the saddle 9. The spindle 11 is, as shown in FIG.
A tool 14 having a positioning ring 15 is held by the chuck 13.

In FIG. 1, a printed circuit board 16 is fixed at a predetermined position on the table 3. A tool holder 20 is provided on one side of the table 3. As shown in FIG. 2, the tool holder 20 is provided with a cassette 22 having a plurality of columns and a plurality of rows of holes formed at predetermined intervals.
A tool post 23 is supported in the hole 22 so as to be movable in the vertical direction. The ring 15 of the tool 14 is on the upper end of the tool post 23
A hole 23A into which is fitted is formed. A stopper 24 is formed on the outer periphery of the upper part of the tool post 23. The stopper 24 contacts the cassette 22 to
23 Downward movement is restricted. Further, a ring 25 is fixed to the lower end of the tool post 23.
A spring 26 is mounted between the and cassette 22. The tool post 23 is always urged downward by the spring 26. A cylinder body 32 is disposed below the cassette 22. The cylinder body 32 has a plurality of columns and rows of cylinders 33.
Are formed at the same intervals as the holes of the cassette 22. The cylinder body 32 has a plurality of fluid passages 34 communicating with the bottom surfaces of the plurality of cylinders 33 arranged in each row. A cap 35 is provided on the upper part of the cylinder body 32. The cap 35 has a plurality of fluid passages 36 communicating with the upper surfaces of the plurality of cylinders 33 arranged in each row. A piston 37 is provided in the cylinder 33 so as to be able to move up and down. The upper end of the piston 37 engages with the ring 25 below the tool post 23. The drive mechanism for raising and lowering the piston 37 is as shown in FIG. That is, the fluid passage 36 communicating with the upper portion of the cylinder 33 is connected to an air pressure source (not shown) via the valve 40. From this air pressure supply source, compressed air at an air pressure P ₁ (pressure required to lower the piston 37) is supplied. The fluid passage 34 communicating with the lower portion of the cylinder 33 is connected to two air pressure sources (not shown) via valves 41 and 42. One of the air pressure sources supplies air pressure P ₂ (piston
Compressed air with the minimum pressure required to raise 37 is supplied, and compressed air with the air pressure P ₃ (pressure required to transfer the tool 14 to the chuck 13) is supplied from the other air pressure supply source. You.

Next, the operation of this embodiment will be described with reference to FIGS.

First, the tool post 23 holding the tool 14 and the spindle 11 are moved to opposing positions by the relative parallel movement of the table 3 and the slider 6, as shown in FIG. thereby opening the fluid passage 36 to the atmosphere by operating, by operating the valve 42 to supply compressed air of the air pressure P ₂ to the valve 41, further fluid passage compressed air of the air pressure P ₂ by operating the valve 41 34 through cylinder 33
Supply within. As a result, the piston 37 moves up, pushes up the tool post 23, and stops the tool post 23 at a predetermined tool change position. In this case, the air pressure P ₂ is
Since the pressure is the minimum pressure required to operate the tool post 23 holding the tool post 23, the ascent speed of the tool post 23 is low, and the tool 14 does not receive an impact even when the tool post 23 stops at the tool change position. From the tool post 23 can be prevented. Next, the spindle 11 is lowered to the tool change position. Then, as shown in FIG. 4 (b),
The shank portion of the tool post 23 is inserted into the spindle 11, and the tool 14 is delivered from the tool post 23 to the chuck 13 of the spindle 11. In this case, since the spindle 11 presses the tool post 23 downward, it is necessary to maintain the tool post 23 in a stopped state against the pressing force. Therefore, by switching the valve 42 to switch the air pressure of the compressed air supplied into the cylinder 33 from P ₂ to P _3.

When the delivery of the tool 14 to the chuck 13 is completed, the valve 41
The valve 42 is operated to open the fluid passage 34 to the atmosphere, and the valve 40 is operated to apply air pressure to the fluid passage 36.
Supplies compressed air of P _1. Then, the piston 37 is pushed down as shown in FIG.
Also, the stopper 24 is pushed down to the standby position where the stopper 24 contacts the cassette 22 by the urging force of the spring 26. At the same time, the spindle 11 rises and returns to a predetermined position. Then, required processing is performed by the tool 14 mounted on the spindle 11.

When the required machining is completed, the spindle 11 is lowered to the tool changing position and the valve 41 and the valve 42 are operated to supply the air pressure P ₂ into the cylinder 33 as shown in FIG. Then, the tool post 23 is raised and stopped at the tool change position. Next, the spindle 11 holding the tool 14 is lowered to the tool change position. In this case, since the spindle 11 presses the tool post 23 downward, it is necessary to keep the tool post 23 stopped at the tool changing position. Therefore, supply compressed air of the air pressure P ₃ in the cylinder 33 by switching the valve 42. In addition, tool post
23 holds the ring 15 of the tool 14 held on the spindle 11, the spindle 11 opens the chuck 14 to release the tool 14, and transfers the tool 14 to the tool post 23.

Thus, when the delivery of the tool 14 from the spindle 11 to the tool post 23 is completed, the spindle 11 moves up to a predetermined position. At the same time, while opening the fluid passage 34 to the atmosphere by operating the valves 41 and the valve 42 actuates the valve 40 to supply compressed air of the air pressure P ₁ in the cylinder 33, in FIG. 4 (e) Press down on tool post 23 as shown.

Next, when another tool 14A (see FIG. 2) is mounted on the spindle 11, the table 3 and the slider 6 are relatively moved in parallel, and the spindle 11 is opposed to the tool post 23 holding the tool 14A. The subsequent operations are performed in the same manner as described above.

〔The invention's effect〕

As described above, according to the present invention, by suppressing the moving speed of the tool holding unit holding the tool to a low level, it is possible to minimize the impact applied to the tool even when the tool holding unit stops at the operating end. As a result, the tool does not come off the tool holding portion, and the reliability of the tool changing device can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a printed circuit board drilling machine to which a tool changing device of the present invention is attached, FIG. 2 is a partial sectional view showing a tool changing state in the tool changing device of the present invention, and FIG. FIG. 4 is a piping system diagram showing a main part of the tool changing device, and FIG. 4 is an explanatory diagram for explaining a tool changing procedure. 1 bed, 2,5 guide, 3 table, 6 slider, 7, 10 motor, 8 feed screw, 9 saddle, 11 spundle, 13 chuck 14 ... Tool, 16 ... Printed circuit board, 20 ... Tool holder, 23 ... Tool post, 33 ... Cylinder, 34,36 ... Fluid passage, 37 ... Piston, 40,41,42 ... Valve .

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B23G 3/155 B23G 3/157

Claims (2)

(57) [Claims] 1. A reciprocating spindle having a tool mounting chuck, a tool holding unit for holding a plurality of types of tools, and a driving unit for reciprocating the tool holding unit with respect to the spindle. A tool changing device that moves the tool holding unit to stop at a predetermined tool changing position, and then moves the spindle to the tool changing position to perform a tool change; wherein the tool holding unit is moved to the tool changing position. A tool changing device for changing a driving force of the driving unit to a value smaller than a driving force for maintaining the tool holding unit in a stopped state at the time of tool change. 2. The tool changing device according to claim 1, wherein the driving force of the driving unit is an air pressure.