JP3378926B2 - Cutting plotter - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutting plotter using an eccentric cutter, and more particularly, to appropriately drive the relative positional relationship of the eccentric cutter in the X and Y directions along a line segment forming a figure. The present invention relates to a cutting plotter in which a plate-shaped or sheet-shaped cutting medium is cut into a desired shape.

[0002]

2. Description of the Related Art In a cutting plotter for controlling the direction of the blade of a rotatable cutter blade having an eccentricity with respect to a rotating shaft by XY movement, for example, FIG.
When the line segments ab and bc refracted at the angle θ as shown in FIG. 1 (A) are continuously cut, the movement locus of the cutter blade is as shown in FIG. As shown, the passing point b is not passed and accuracy cannot be obtained. Therefore, in order to cut as instructed by the host computer, the intersection angle of two consecutive line segments is calculated, and when the calculated angle is less than or equal to a predetermined angle, the line segment on the extension line of the cutout direction of the line segment currently being focused on is calculated. Then, a dummy point assumed at a position distant from the final tip of the line segment by a distance corresponding to the eccentricity is commanded as a drive target coordinate, and further, from the drive target coordinate centering on the final tip of the line segment. A cutting plotter that issues a rotational drive command with the eccentricity as a radius up to the next line segment is disclosed in Japanese Patent Publication No. 2-153.
No. 58 is disclosed.

[0003]

In the above cutting plotter, as shown in FIG. 12, first, the rotation center 4 of the cutter blade 2 overruns the eccentric amount D from the end 6a of the line segment 6. Next, as shown in FIG.
With the blade edge 2a of the cutter blade 2 penetrating into the fulcrum as a fulcrum, the cutter blade 2 is rotated until the rotation center 4 is positioned on the next line segment 10.

In this case, the pressure of the cutter blade 2 acts in the direction of compressing the cutting medium 8 in the next cutting direction. Therefore, there is a problem that the cutting start of the next line segment 10 is disturbed and the cutting quality is deteriorated. Further, when the cutter blade 2 rotates, a large pressure friction acts on the blade surface 2b from the cutting medium 8 and the blade surface 2b is easily deteriorated. In order to remove this defect, the above-mentioned patent publication proposes to raise the cutter blade 2 from the cutting medium 8. However, raising the cutter blade for each cutting direction changing operation is the cutting time. If the center of rotation of the cutter blade 2 deviates even a little while rotating along a circular orbit, as shown in FIG. 14, the corners of the cutting loci 6b, 10b based on the two line segments 6, 10 In the gap 12
There was a defect that the cutting locus was not connected due to the formation of a crack. The present invention aims to eliminate the above defects.

[0005]

[Means for Solving Problems] In order to achieve the above object,
In the present invention, the blade edge 36d of the cutter blade 36c is attached to the rotary shaft 38.
The cutter holder 36a is eccentrically separated by a distance D from the
A head 20 supported on the above, an X, Y drive unit 40 for driving the relative positional relationship between the head 20 and the cutting medium 26 in the X and Y directions, and a Z drive unit 42 for driving the cutter holder 36a in the vertical direction. , A crossing angle calculation unit 54 that calculates a crossing angle of two consecutive line segments when the relative positional relationship is driven in X and Y along a line segment that forms a figure, and the calculated angle is a predetermined angle. At the following time, the first overrun position 58 on the extension line in the cutting direction of the line segment 56 of interest is added to the eccentric amount D plus a predetermined extension amount α on the extension line in the cutting direction. As the drive target coordinates of the line segment 56.
In the direction of the starting point of the cutter blade 36 at the predetermined extension amount α.
The position 62 of the portion c of the penetrating the cutting medium 26 is returned by a distance obtained by adding the maximum width β in the horizontal direction to the cutting medium 26, and is commanded as the second drive target coordinate.
Further, with the final tip 56a of the line segment 56 as the center, the rotational drive with the radius obtained by subtracting the maximum width β from the eccentric amount D from the second drive target coordinate to the next line segment. It is provided with an X, Y drive control unit 46 for instructing.

[0006]

When the cutter blade 36c is rotated, pressure back from the cutting medium 26 is applied to its back portion 36e, but almost no pressure friction is applied to the blade surface 36f. In addition, the cutting medium 26 has a side 2 opposite to the next cutting direction.
Since the pressure of the cutter blade 36c is applied to the 6b in the compression direction, the cut end of the next line segment 60 at the start of cutting is not disturbed. Also,
Since the cutting loci 26a and 26c of the cutter blade 36c cross each other, the two line segments can be reliably connected.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be described below in detail with reference to the embodiments shown in the accompanying drawings. FIG. 2 shows the outline of the cutting plotter, and 20 is driven in the XY directions with respect to a support 28 supporting the cutting medium 26 in association with XY drive sources 22 and 24 (see FIG. 4) such as a servomotor. The Z drive source 34 (see FIG. 4), which is a well-known head and drives the elevating arms 30 and 32 in the vertical direction, and includes a known moving coil and the like. The lifting arms 30 and 32 are the cutter holders 36a of the eccentric cutter 36.
Is held detachably. A rotary body 36b is freely rotatably provided on the cutter holder 36a. 38
Indicates the rotation axis of the rotating body 36b, and the rotation axis 38 is set coaxially with the central axes of the cutter holder 36a and the rotating body 36b, and is set perpendicular to the support surface of the support body 28.

Reference numeral 36c denotes a cutter blade detachably attached to the rotating body 36b, and its blade edge 36d is eccentric to the rotating shaft 38 by a distance D as shown in FIG. The XY drive sources 22 and 24 shown in FIG. 4 are driven by an XY drive unit 40, and the Z drive source 34 is a Z drive unit 4.
It is configured to be driven by two. These X
The Y drive unit 40 and the Z drive unit 42 are configured to be controlled by the XY drive control unit 46 and the Z drive control unit 48 of the controller 44.

In the construction of the cutting plotter described above, when the driving force F in an arbitrary direction is applied to the rotating body 36b by the movement of the head 20, as shown in FIG.
A force Fγ for rotating the cutter blade 36c about 6d acts on the cutter blade 36c itself. Therefore, when the cutter holder 36a is driven along the line segment forming the figure, the cutter blade 36 naturally moves in the direction along the line segment.
c rotates, and the cutter blade 36c substantially follows the tangential direction of the cutout shape.

In FIG. 4, reference numeral 50 is a coordinate memory which stores coordinate information necessary for specifying a line segment of a desired shape given by the host CPU, and is configured to be controlled by the CPU 52 of the controller. Has been done.
Reference numeral 54 is an intersection angle calculation unit that calculates an intersection angle formed by two continuous line segments based on the coordinate information read from the coordinate memory 50.

The XY drive control unit 46 and the Z drive control unit 48 are configured to selectively execute the following operations according to the magnitude of the intersection angle calculated by the calculation unit 54. When the crossing angle is equal to or larger than the predetermined angle, in other words, when the line segment currently under consideration (that is, to be cut out from this point) and the next line segment intersect at a relatively obtuse angle. Uses the coordinates read from the coordinate memory 50 as the drive target coordinates and directly commands the X, Y drive unit 40 in the next stage.

When the intersection angle is smaller than a predetermined angle, in other words, when two line segments intersect each other at an angle equal to or smaller than the predetermined angle, X
The Y drive control unit 46 and the Z drive control unit 48 execute the following operations. In FIG. 6, first, the eccentric amount D of the cutting edge 36d from the final tip 56a of the line segment 56 on the extension line in the cutting direction of the line segment 56 that is currently focused (that is, to be cut out from now) The position 58 separated by a distance corresponding to the value obtained by adding α to the overrun position 58 is determined.

The above α is the line segment 5 to be cut out.
It is for cutting out the cutting medium 26 by slightly extending it from 6, and is set to an appropriate value in advance by the panel operation of the controller 44. The coordinates of the obtained overrun position 58 are used as drive target coordinates, and an instruction is given to the XY drive unit 40 and the Z drive unit 42 in the next stage. Cutter blade 36c
Cuts the cutting medium 26 along the line segment 56 in the arrow direction as shown in FIG. 6 until the rotation center 38 of the cutter blade 36c reaches the overrun position 58.

Next, as shown in FIG. 7, the XY drive control unit 46 moves the rotation center 38 of the cutter blade 36c from the position 58 along the line segment 56 in the opposite direction of α + β, that is, the line segment 5
6 is moved to the position 62 in the direction of returning to the starting point direction. As shown in FIG. 8, the above β is the support 28 of the portion 36e of the cutter blade 36c that penetrates the cutting medium 26.
Is the distance in the horizontal direction with respect to the support surface of the
Depends on the thickness of the cutting medium 26.

The above β is stored in the memory of the controller 44 in advance by a panel operation. This α
The return amount of + β is set so that the orientation of the cutter blade 36c does not change. By the movement of the cutter blade 36c in the return direction, the blade tip 36d of the cutter blade 36c is
As shown in FIG. 7, the portion P located on the upper surface of the cutting medium 26 of the cutter blade 36c is α + β from the end of the cutting trajectory 26a of the cutter blade 36c, and is on the side of the starting point direction of the line segment 56. It is located at the end 56a.

Next, the Z drive controller 48 controls the cutter blade 3
The pressure of 6c on the cutting medium 26 is reduced. Next, the XY drive control unit 46, as shown in FIG.
End 56a of 6, ie the cutting medium 2 of the cutter blade
6 is centered on a portion P located on the upper surface of 6 and the eccentricity amount D-
The rotation center 38 of the cutter blade 36c is moved to the next line segment 60 along the locus of a circle 59 (see FIG. 1) having a radius of β.

At this time, the cutter blade 36c rotates around the portion P located on the upper surface of the cutting medium 26. During this rotation, the spine 36e (see FIG. 9) of the cutting edge 36d receives pressure friction from the cutting medium 26, but the blade surface 36f hardly receives pressure friction.

The rotation of the cutter blade 36c about the portion P acts in the direction of compressing the cutting medium (26) at the portion 26b (see FIG. 9) opposite to the next cutting direction. , This compressive force does not affect the cutting start point portion of the next line segment 60. Therefore, the cut end of the next line segment 60 at the start of cutting is in a good state. Further, by the overrun cutting for α, the notch 26c (FIG. 9A) is formed before the portion P of the cutter blade 36c.
(Refer to FIG. 3), the pressure friction from the cutting medium 26 to the cutter blade 36c becomes small, and the cutter blade 3
6c can be smoothly rotated.

Reference numerals 26a and 26c in FIG. 10 show cutting trajectories when the cutting medium is cut along two right-angled line segments.
6, 60 are surely connected and cut. Next, the Z drive control unit 48 controls the cutting medium 2 of the cutter blade 36c.
6 and the XY drive control unit 46
Controls the movement of the cutter blade 36c along the next line segment 60. The arrow direction in FIG. 1 indicates the rotation center 3 of the cutter blade 36c.
The locus of 8 is shown.

[0020]

Since the present invention is configured as described above, it is possible to reduce the wear of the cutter blade, improve the quality of the line segment at the start of cutting, and further intersect at an angle smaller than a predetermined angle. There is an effect that two line segments can be reliably connected.

[Brief description of drawings]

FIG. 1 is an explanatory diagram.

FIG. 2 is a schematic side view of a cutting plotter.

FIG. 3 is an explanatory diagram.

FIG. 4 is a block diagram.

FIG. 5 is an external view of an eccentric cutter.

FIG. 6 is an explanatory diagram.

FIG. 7 is an explanatory diagram.

FIG. 8 is an explanatory diagram.

FIG. 9 is an explanatory diagram.

FIG. 10 is an explanatory diagram.

FIG. 11 is an explanatory diagram of a conventional technique.

FIG. 12 is an explanatory diagram of a conventional technique.

FIG. 13 is an explanatory diagram of a conventional technique.

FIG. 14 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

2 cutter blade 4 center of rotation 6 line segments 8 cutting media 10 line segments 12 gaps 20 heads 26 cutting media 28 Support 30 lifting arm 32 Lifting arm 36 eccentric cutter 36a cutter holder 36b rotating body 36c cutter blade 36d cutting edge 38 rotation axis 44 controller 56 line segments 58 Overrun position 60 line segments 62 position

Claims (2)

(57) [Claims] 1. A cutting edge (36d) of a cutter blade (36c).
A head (20) rotatably supported by a cutter holder (36a) eccentrically by a distance D from a rotary shaft (38), and a relative positional relationship between the head (20) and the cutting medium (26) is X, X, Y drive unit (40) driven in Y direction
And a Z drive unit (42) for driving the cutter holder (36a) in the ascending / descending direction, and two continuous line segments when the relative positional relationship is X, Y driven along a line segment that constitutes a figure. A crossing angle calculation unit (54) for calculating a crossing angle, and when the calculated angle is less than or equal to a predetermined angle, the line segment (56) is on the extension line in the cutout direction of the line segment (56) currently focused on.
From the final tip (56a) of 6), an overrun position (58) obtained by adding a predetermined extension amount α to the eccentric amount D is commanded as a first drive target coordinate, and further, from the first drive target coordinate, In the direction of the starting point of the line segment (56), the predetermined extension amount α
The portion of the cutting blade (36c) that penetrates the cutting medium (26).
The maximum return distance β in the horizontal direction with respect to the return position (6
2) as the second drive target coordinate, and further, the eccentricity amount from the second drive target coordinate to the next line segment centering on the final tip (56a) of the line segment (56). A cutting plotter comprising: an X and Y drive control unit (46) for instructing a rotational drive with a radius obtained by subtracting the maximum width β from D. 2. The Z drive control section (48) issues a command to weaken the pressure of the cutter blade (36c) against the cutting medium (26) during the rotational drive. Cutting plotter described in.