JPH0763905B2 - Automatic tool changer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to an automatic tool changer (AT) for a machining center.
Regarding C). More specifically, it relates to an automatic tool changer in which an ATC operation is performed by a cam and a link mechanism.

[Prior Art] Conventionally, automatic tool changers can be classified into a cam system, an oil system, and a pneumatic system, according to drive systems. The cam system is driven by turning and forward / reverse drive sources of the tool changing arm.The hydraulic / pneumatic system is a combination of linear drive cylinders as drive sources, or a linear drive cylinder and a rotary drive. Driven in combination with a shaped cylinder,
It has been known that a tool change operation is performed by using two or more drive sources.

In JP-A-60-213454, a roller gear cam is driven by one motor, a follower roller engaged with the roller gear cam rotates an arm shaft for tool change, and a lever engaged with a plane groove cam directly connected to the roller gear cam. Describes the one that causes the arm shaft to perform the lift operation. Also,
JP-A-61-164743 discloses a similar one in which the roller gear cam is replaced by a parallel cam and the plane groove cam is replaced by a drum cam.

[Problems to be Solved by the Invention] However, the hydraulic / pneumatic drive system has a problem that it requires a control device, wiring, and piping, and has a complicated structure, which makes maintenance difficult. Further, in the cam drive system described in the above-mentioned JP-A-60-213454 and JP-A-61-164743, since the lever is composed of one lever, the specifications of the machining center change every time. It is necessary to change the shape of the plane groove cam or change the lever ratio. That is, the lift amount and rotation amount of the arm shaft and the operation timing of the replacement arm differ depending on the specifications of the machining center. The present invention solves the above-mentioned conventional problems.

An object of the present invention is to provide a link mechanism in which a lever ratio for driving an arm shaft can be easily changed.

Another object of the present invention is to perform a linear / swivel motion of a tool exchanging arm with one drive source, and a structure that requires only one swivel of the arm per tool change, and an automatic tool exchanging device that simplifies the operation. Is provided.

Still another object of the present invention is to provide an automatic tool changer capable of shortening the tool change time on the tool spindle.

[Means for Solving Problems] The following means are adopted to solve the problems.

A tool spindle (20) provided movably with respect to the column (6) and on which a tool (31) is mounted, and a tool storage magazine (30) provided in the column at the end of the tool spindle in the moving direction. An automatic tool changer for exchanging the tool between two tools, the tool being provided between the tool spindle and the tool storage magazine, and between the two positions of the tool storage magazine side and the tool spindle side. An arm unit main body (121) capable of reciprocating in the same direction as the main spindle moving direction is provided between the column and the arm unit main body, and moves the arm unit main body in the same direction as the tool main spindle moving direction. A moving means (130, 134, 138) for moving the tool, and a tool exchange arm (105) rotatably provided on the arm unit body for exchanging the tool between the tool spindle and the tool storage magazine. A roller gear cam (53) provided on the arm unit main body and operating to rotate the tool changing arm around its axis, and a cam (58) provided on the arm unit main body and operating in conjunction with the roller gear cam. And a plurality of levers (72, 77) provided between the cam and the tool changing arm and provided on the arm unit main body and engaged with the cam and the tool changing arm, respectively.
And a link (75), which is provided in the arm unit main body, and a link mechanism (70) which operates to move the tool changing arm forward and backward along the shape of the cam in the axial direction of the tool changing arm. A roller gear cam and a driving body (40) for driving the cam, and moved to the tool exchange position on the tool exchange arm of the arm unit main body that is on standby and moved to the tool spindle side. The automatic tool changer is characterized in that the tool of the tool spindle is inserted and the three operations of rotation, forward movement, and backward movement of the tool exchange arm are linked in an overlapping manner.

A feature of the present invention is that the link mechanism is configured by combining a plurality of linear and L-shaped levers and links, so that the lever ratio can be easily changed.

[Operation] When the arm drive motor 40 rotates, the globoidal cam 53 and the side surface cam 58 are rotationally driven via the gear transmission mechanism. The rotation of the globoidal cam 53 rotates the arm shaft 100 via the cam follower 60. At the same time, the arm shaft 100 is lifted by the cam lever mechanism 70 engaged with the side surface cam. Arm axis 1 by rotating and lifting arm axis 100
The tool change operation is performed by the twin arm 101 provided at the tip of 00.

Further, the arm unit main body 121 moves to the tool spindle 20 side and stands by by the operation of the moving means 130, 134, 138 prior to the tool exchange. After the tool is replaced with the tool spindle 20, the arm unit body 121 is moved to the tool storage magazine 30 side by the operation of the moving means.

[Embodiment] An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a front view when the automatic tool changer of the present invention is applied to a column travel type machining center 1. FIG. 2 shows the left side view. A column base 3 is provided on the bed 2 slidably along the X-axis slide guide surface 4 in the X-axis direction. Further, on the column base 3, a vertical column 6 is mounted which is driven by a Z-axis servomotor 9 to rotate the screw shaft and slide in the Z-axis direction. Therefore,
The upright column 6 can be slidably moved in the illustrated X and Z axis directions (that is, in a plane).

The linear movement of the column base 3 in the X-axis direction is driven by rotating the screw shaft 8 by the X-axis servomotor 7. A spindle head 7 is provided on the vertical column 6 so as to be vertically movable, that is, in the Y-axis direction. The movement of the spindle head 7 in the Y-axis direction is driven by rotating the feed screw 11 by the Y-axis servomotor 10. A tool spindle 20 is provided in the spindle head 7 with its axis extending horizontally. A tool magazine 30 that can be rotationally indexed is provided on the upper surface of the vertical column 6. Tool magazine 30
Is a turret type and has a large number of tools 31 arranged on the circumference.

This tool magazine 30 allows you to select the desired tool 31 if called.
It is a well-known tool magazine that can be indexed and positioned at a predetermined position. The twin arm 105 is mounted on the arm unit main body 121 that takes three positions. The arm unit body 121 is moved up and down by a drive device described later. The twin arm 105 grabs the tool 31 in the tool magazine 30, moves it to the tool spindle 20 side, and rotates 180 degrees with the tool 31 of the tool spindle to exchange the two.

What is shown in FIG. 3 is a developed view of a drive device for driving the twin arm 105. An arm drive motor 40 is attached to the box-shaped tool changing arm body 41. A bevel gear 43 is key-connected to an output shaft 42 that outputs the rotational driving force of the arm drive motor 40. The bevel gear 43 is rotatably supported by a bearing 44 provided on the tool changing arm body 41. The bevel gear 43 meshes with the bevel gear 45. Bevel gear 45
A small diameter spur gear 46 is provided integrally therewith. The bevel gear 45 and the small diameter spur gear 46 are both keyed to the shaft 47.

A gear 48 is keyed to an intermediate portion of the shaft 47. Further, a chain wheel 49 is keyed to the other end of the shaft 47. A large-diameter large spur gear 51 meshes with the small-diameter spur gear 46. The large diameter spur gear 51 is fixed to a globoidal cam (roller gear cam) 53 by a positioning pin 55 so as not to move relatively, and is clamped by a bolt 56. On the outer circumference of the globoidal cam 53, a spiral groove 54
Is formed.

The spur gear 57 is rotatably provided on the shaft 52. A side cam 58 is provided integrally with the spur gear 57. On the other hand, in the spiral groove 54,
The roller 61 of the cam follower 60 is inserted. A spur gear 63 is fixed to one end of a shaft 62 that fixes the cam follower 60, and the spur gear 63 meshes with the spur gear 90 (Fig. 5). The spur gear 90 is keyed to the arm drive shaft 91. A spline shaft 92 is formed at the other end of the arm drive shaft 91.

A roller 71 is inserted in the cam groove 59 of the side surface cam 58. The roller 71 is fixed to one end of the swing lever 72.
The swing lever 72 is rotatably provided on the shaft 73. FIG. 4 is a side view of the link mechanism 70. FIG. 6 is a development view of the link mechanism 70. The roller 71 is fixed to substantially the center of the swing lever 72. One end of the swing lever 72 is
It is rotatably provided. A shaft 74 is fixed to the other end of the link 72. One end of a link 75 is rotatably provided on the shaft 74 via a bearing.

The other end of the link 75 is rotatably provided on one end of the shaft 76 via a bearing. The other end of the shaft 76 is fixed to one end of a swing lever 77. The swing lever 77 has an L-shape. The L-shaped corner portion is rotatably provided on the shaft 52. A shaft 78 is fixed to the other end of the swing lever 77.
At the other end of the shaft 78, one end of a link 79 is rotatably provided. The other end of the link 79 is rotatably provided on the shaft 80.
A shifter 81 is fixed to the shaft 80.

An arm shaft 100 having spline teeth on its inner peripheral surface is engaged with the spline shaft 92 of the arm drive shaft 91. A flange 101 is integrally formed on the outer circumference of the arm shaft 100.
Since the shifter 81 is sandwiched by the flange 101 and the flange 102 via the bearing, the flange 102, the nut 103
It is screwed and fixed by. A twin arm 105 is fixed to one end of the arm shaft 100.

On the other hand, the shaft 110 is fixed to the tool change arm body 41. A chain wheel 111 is rotatably supported on the shaft 110 via bearings. On the side of the chain car 111, the cylinder 1
12 are fixed together. A dog 113 is fixed to the outer circumference of the cylindrical body 112. A proximity switch 114 is fixed to the arm body 41 at the rotation position of the dog 113. A chain 115 is stretched between the chain wheel 111 and the chain wheel 49.

Arm unit vertical drive device On the upper part of the vertical column 6, a cylinder 122 having a circular sliding surface 123 having a circular cross section in the Y-axis direction and a prism 124 having a U-shaped sliding surface 125 in three directions are provided in parallel. is there. An arm unit body 121 is provided slidably on the circular sliding surface 123 and the sliding surface 125. The tool exchange arm body 41, the twin arm 105, and the like described above are mounted on the arm unit body 121. On the inner surface of the arm unit body 121,
A slider 126 having a groove 127 in the X-axis direction is fixedly provided.

On the other hand, a cylinder 130 is fixedly provided in the Y-axis direction of the standing column 6. The cylinder 130 is provided with a piston 131 that operates hydraulically. A rack 133 is formed on the piston rod 132. A pinion 134 is engaged with the rack 133. The pinion 134 is fixed to the shaft 135 with a key. The shaft 135 is rotatably provided on the vertical column 6 by a bearing 136. A flange 137 is formed at one end of the shaft 135. A crank 138 is fixed to the flange 137. A pin 139 is fixed to the tip of the crank 138. The pin 139 is inserted in the groove 127. The operation is as follows. Hydraulic pressure is introduced into the cylinder 130 and the piston 131 moves inside the cylinder 130. Piston rod 132
The rack 133 formed in the above turns the pinion 134. Pinion 13
When the 4 rotates, the crank 138 swings, and the pin at the tip moves up and down while sliding in the groove 127.
21 is also moved up and down.

Even if the piston 131 moves at a constant speed, the arm unit body 1
21 moves slowly at the vertical position and at a high speed in the middle, which is good for the tool changing operation described later.

Operation of Automatic Tool Changer FIG. 9 is a diagram showing an operation sequence of the automatic tool changer. The arm unit 120 is positioned at an intermediate position between the tool magazine 30 and the spindle head 7 and stands by (step). When a tool change command is issued, the spindle head 7 moves to the tool change position, and the tool at the tip of the tool spindle 20 moves to the twin arm 105.
After being inserted into the tool, the tool of the tool spindle 20 is unlocked (step). The twin arm 105 pushes the tool of the spindle head 7 forward and pulls it out (step). The twin arm 105 turns 180 degrees (step).

The tool attached to the opposite end of the twin arm 105 is inserted into the tool spindle 20 (step), the tool is locked in the tool spindle 20, and at the same time the spindle head 7 moves to the machining position (step). The twin arm 105 is extended in the Z-axis direction (step). The twin arm 105 rises in the Y-axis direction and is positioned on the tool pot on the tool magazine 30 (step). Twin Arm 105 is a tool magazine 30
The tool held by the twin arm 105 is inserted into the magazine 30. (Step) When the tool is locked in the tool magazine 30, the arm unit 120 starts descending (step). The tool magazine 30 rotates to index the required next tool to be used (step). The arm unit 120 rises and holds the tools in the tool magazine 30 (step). Twin arms
The 105 lifts in the Z-axis direction and pulls out the tool in the magazine (step). The arm unit 120 descends to the Y-axis origin and waits in a state of entering the Z-axis direction (steps, ...).

The feature of the above tool exchange operation is that the tool exchange of the tool spindle 20 is a step-to-step operation. Further, since the tools can be stored in the tool magazine 30 and the standby tools can be selected during machining, the tool replacement time can be greatly shortened.

Forward / backward movement of twin arm 105, rotation operation The above-described operation is a tool exchange operation. Next, the retracting / rotation operation of twin arm 105 will be described according to the movement of the mechanism. When the arm drive motor 40 starts rotating, the bevel gear 43, the bevel gear 45, and the small diameter spur gear 46 are driven to rotate. When the small diameter spur gear 46 is driven to rotate, the large diameter spur gear
51, the globoidal cam 53 is rotated. The globoidal cam 53 rotates the cam follower 60, the shaft 62, and the spur gear 63. The rotation of the spur gear 63 rotates the spur gear 90 and the arm drive shaft 01.

The rotation of the arm drive shaft 91 rotates the twin arm 105 by 180 °. At the same time as this operation, the rotation of the shaft 47
Rotate spur gear 48 to rotate spur gear 57 to rotate side cam 58
Rotate. When the side surface cam 58 rotates, the roller 71 moves along the cam groove 59. This movement uses the swing lever 72 as an axis.
Swing 73 around. This swinging movement of the swinging lever 72 moves the link 75 and swings the swinging lever 77 about the shaft 52.

The swing lever 77 swings around the shaft 52 to move the link 79 and the shaft.
80, shifter 81 along with spline shaft 92 arm shaft 100
In the axial direction. In this hoisting operation, the twin arm 105 moves the tool 31 into the tool spindle 20 or the tool magazine 30.
It is an operation for appearing and disappearing. On the other hand, this hoisting / moving operation is performed by the shaft 47, the chain car 49, the chain 115, and the chain car 111.
To rotate. When the cylindrical body 112 fixed to the chain wheel 111 rotates, the dog 113 is detected by the proximity switch 114 and stopped.

In this stop position, the twin arm 105 moves the tool to the tool spindle 2
It is an operation of inserting or withdrawing to or from the tool magazine 30. The operation of the series of twin arms 105 is the seventh.
To be driven according to the sequence of operations shown in the figure,
The cam groove 59, the swing lever 72, the link 75, the swing lever 77, and the arm unit 120 are designed, adjusted, and assembled so that the timings match.

[Other Embodiments] The arm drive motor 40 of the above embodiments is a rotating electric motor, but may be a drive motor such as a hydraulic cylinder or a hydraulic rotary motor. Further, the link mechanism 70 described above,
It is composed of three rocking levers 72, links 75, and rocking levers 77, but a similar link mechanism may be made by adding other links and levers.

[Effect of the Invention] Since the automatic tool changer of the present invention is configured with the cam link mechanism by combining a plurality of levers, it is possible to change the specifications of the machining center simply by changing the lever ratio.

In the tool change of the twin arm of the present invention, since three operations of forward movement, backward movement, rotation and backward movement are carried out in series, very few movements are required, and mechanical movements are made by using the globoidal cam and the link mechanism. Therefore, a plurality of motions can be overlapped and exercised with good timing.

Further, since the globoidal cam and the link mechanism are used for driving the tool change of the twin arm according to the present invention, it is possible to operate smoothly without backlash.

Further, the automatic tool changer of the present invention comprises an arm unit main body capable of reciprocating between two positions on the tool storage magazine side and the tool spindle side in the same direction as the moving direction of the tool spindle, and a moving means for moving the arm unit main body. Since it has and, it also has the following effects.

In other words, by moving the arm unit body to the tool spindle side and making it stand by, the tool attached to the tool spindle can be inserted into the tool exchange arm simply by moving the tool spindle to the tool exchange position. Yes, you can move on to the tool withdrawal operation. Then, after a new tool is mounted on the tool spindle by the advancing / retreating operation and the rotating operation of the tool exchanging arm, the tool spindle is moved to the machining position so that machining can be performed immediately. In this way, the movement of the tool exchanging arm on the tool spindle is reduced and the movement distance of the tool spindle for tool exchange is shortened, so that the tool exchange time can be shortened.

Further, by moving the arm unit main body to the tool storage magazine side, it is possible to select and grip the next tool without interfering with the spindle head during machining.

Since the automatic tool changer of the present invention has a simple structure, maintenance is easy.

[Brief description of drawings]

FIG. 1 is a front view of a machining center, FIG. 2 is a side view of FIG. 1, FIG. 3 is a development view of a drive device of a tool changing device, and FIG. 4 is a view seen from a direction IV of FIG. FIG. 5 is a view seen from the direction V in FIG. 3, FIG. 6 is a developed view of the lever mechanism, and FIG. 7 is a cross-sectional view of the arm unit main body in the XZ axis plane,
FIG. 8 is a sectional view taken along the line VIII-VIII in FIG. 7, and FIG. 9 is a flow chart of the automatic tool changing operation. 1 …… Column travel type machining center, 2 …… Bed, 3 …… Column base, 20 …… Tool spindle, 30 …… Tool magazine, 40 …… Arm drive motor, 53 …… Glovoidal cam, 5
8 …… Side cam, 60 …… Cam follower, 70 …… Link mechanism,
100 …… Arm axis, 120 …… Arm unit

Front page continuation (72) Inventor Jiro Watanabe 1 Abiko, Abiko, Chiba Prefecture, Hitachi Seiki Co., Ltd. (56) Reference JP 61-44546 (JP, A) JP 1-115539 (JP, A) ) JP-B-48-25356 (JP, B1)

Claims (1)

[Claims] 1. A tool spindle (20) provided movably with respect to a column (6) and having a tool (31) mounted thereon,
An automatic tool changer for exchanging the tool with a tool storage magazine (30) provided in the column at the end of the tool spindle in the moving direction, wherein the tool spindle and the tool storage magazine are provided. An arm unit main body (121) that is reciprocally movable between two positions of the tool storage magazine side and the tool spindle side in the same direction as the movement direction of the tool spindle, and the column and the arm unit body. A moving means (130, 134, 138) provided between the arm unit main body and the tool main spindle for moving in the same direction as the tool main spindle moving direction; A tool exchanging arm (105) for exchanging the tool between the arm unit body and the arm exchanging arm so as to rotate the tool exchanging arm around its axis. A roller gear cam (53) to be moved, a cam (58) provided in the arm unit body and operating in conjunction with the roller gear cam, and provided between the cam and the tool changing arm and in the arm unit body. And a plurality of levers (72, 77) respectively engaged with the cam and the tool change arm.
And a link (75), which is provided in the arm unit main body, and a link mechanism (70) which operates to move the tool changing arm forward and backward along the shape of the cam in the axial direction of the tool changing arm. A roller gear cam and a driving body (40) for driving the cam, and moved to the tool exchange position on the tool exchange arm of the arm unit main body that is on standby and moved to the tool spindle side. An automatic tool changer characterized in that a tool of the tool spindle is inserted, and three operations of rotation, forward movement and backward movement of the tool exchange arm are overlapped and interlocked.