JPH05269694A - Cutter head control method for cutting plotter - Google Patents

Abstract

PURPOSE:To decrease, to the possible minimum the amount of cutting material pinched by a knife edge in a starting point and a bending point of a segment by providing a driving means for turning the direction of a knife edge seen from the center of rotation of a cutter to a plurality of preset reference directions. CONSTITUTION:When a cutter blade 18 cuts a first segment to its terminal point, a cutter head 11 is raised, and in the raised state, the cutter blade 18 is turned in one reference direction closest to the direction of a second segment to be cut, out of plural reference directions, by driving means 21, 22, 23. By the movement of the cutter head 11, the starting point of the second segment is caused to match the knife edge of the cutter, and the knife edge lands on the starting point of the second segment. In such a condition, the rotational center of the cutter blade 18 is turned in circular motion around the knife edge from the reference direction line to the second segment so that the direction of the cutter blade 18 matches the direction of the second segment. Hereinafrter, the cutter 17 is moved along the second segment to cut two segments.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cutter head control method for a cutting plotter which cuts an adhesive sheet or the like using a cutter blade.

[0002]

2. Description of the Related Art Conventionally, the center of rotation of a rotatable cutter attached to a cutter head and the blade edge of the cutter are eccentric to each other to utilize the caster action, and the trajectory of the blade edge follows the movement of the cutter head. No. 2-15358. In the above prior art, when cutting two continuous line segments at an angle,
As shown in FIG. 9, with the cutter head lowered, the center of rotation of the cutter is located on the extension line of the first line segment α in the cutting direction and corresponds to the eccentricity D of the cutting edge from the end point of the line segment. After moving to a position P1 separated by a distance and cutting the first line segment α to the end point, the center of rotation P of the cutter P
Is moved from P1 on the extension line of the first line segment α to P2 on the second line segment β by an arc motion with the eccentricity D as a radius with the cutting edge as the center, and the orientation of the cutter is changed to the second line segment. A method has been performed in which the cutter is moved along the second line segment β so as to match the direction of β, and the two line segments α and β are continuously cut. Therefore, at the bending point where the two line segments α and β intersect, the entire cutter blade rotates horizontally around the blade edge, and the inclined surface toward the tip of the cutter blade twists the cutting material such as the adhesive sheet in the rotation direction. become,
When the angle between the two line segments is acute, the rotation angle (θ2) of the cutter blade is close to 180 degrees at maximum, and the angle at which the cutter blade twists the adhesive sheet becomes large, so the adhesive sheet may be deformed or sticky. The layers may peel off.

[0003]

The pressure-sensitive adhesive sheet or the like cut off by the conventional cutting plotter has difficulty in finishing the corner portion at an acute angle, which may cause a problem in finished quality. Also, if the adhesive layer of the adhesive sheet is damaged,
When the corner portion is deformed, there is a problem that dust or water enters from this portion and is easily peeled off.

Therefore, the present invention is intended to improve the finished quality of the bent portion of the cut line segment, prevent deformation and damage of the cutting material, and improve the quality and durability of the final product. is there.

[0005]

DISCLOSURE OF THE INVENTION The present invention is proposed in order to achieve the above-mentioned object. The cutter is rotatably mounted on the cutter head, and the blade edge of the cutter is eccentric with respect to its rotation center. Then, in a cutting plotter that cuts the cutting material by making the cutting edge follow the movement of the cutter head, the direction of the cutting edge viewed from the rotation center of the cutter is rotated to a plurality of preset reference directions. When cutting two continuous line segments, the cutter head is raised at the end point of the first line segment, and the direction of the cutting edge of the cutter is moved to the reference direction closest to the second line segment by the driving means at the raised position. Rotate to and move the cutter head so that the starting point of the second line segment and the cutting edge of the cutter match, and then move the cutter head. In the descending position, the center of rotation of the cutter is moved from the reference direction line to the second line segment by an arc motion centered around the blade edge of the cutter and having the eccentricity as a radius, and the direction of the cutter and the second direction The present invention provides a method for controlling a cutter head in a cutting plotter, which is characterized in that the cutter head is controlled so that the directions of the line segments are matched.

[0006]

When the cutter blade cuts the first line segment to the end point, the cutter head rises, and in this raised state, the cutter blade is one of the plurality of reference directions that is closest to the direction of the second line segment to be cut. It is rotated in one reference direction. By the movement of the cutter head, the starting point of the second line segment and the cutting edge of the cutter are aligned, and the cutting edge lands on the starting point of the second line segment.

In this state, the center of rotation of the cutter blade is circularly moved from the reference direction line to the second line segment about the blade tip, and the direction of the cutter blade and the direction of the second line segment coincide with each other. After that, the cutter is moved along the second line segment to cut two continuous line segments.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a cutter head 11, which is mounted on a head carriage of a cutting plotter (not shown) and is driven in the XY direction on the drawing board together with the head carriage, and a head mounting arm 12 of the head carriage is provided.
The cutting material is cut by moving up and down.

The cutter head 11 accommodates a cutter holder 14 in an outer cylinder 13. Cutter holder 14
Is equipped with a cutter 17 via an upper pivot bearing 15 and a lower radial bearing 16, and the cutter 17 is rotatable with respect to the cutter holder 14. The cutter 17 has a cutter blade 18 formed at the lower end thereof, and a rotary shaft portion provided with a reflection plate 19 for position detection, which will be described later.
20 and the magnet 21 are fixed. Also, 22, 23
Is a coil fixed in a cylindrical holder 24 fixed to the lower end of the head mounting arm 12, and 25 and 26 are reflection type photo sensors.

FIG. 2 shows the arrangement of the coils 22, 23, 27, 28, and the coils 22, 23, 27, 28 are formed by winding conductive wires on both ends of two arc-shaped yokes 29, 30, respectively. The coils 22 and 23, 27 on both ends of the yokes 29, 30
And 28 are respectively connected in series. One of the yokes 29 has its mounting position rotated by 90 ° with respect to the other yoke 30, and the coils 22, 23, 27, 28 are arranged on the four sides around the magnet 21 provided on the shaft of the cutter 17. ..

The magnet 21 attached to the cutter 17 has the south pole facing outward, and as shown in FIG.
The blade edge C of is oriented in the same direction as the S pole. Figure 2
When the middle right is in the X direction (0 °) and the upper is in the Y direction (90 °), if a + current is passed from the terminals a1 to a2, the magnet S
The pole repels the coil 22 on the 0 ° side, is attracted by the coil 23 on the opposite 180 ° side, and the cutter 17 is in the rotating position shown in the figure, and is in the cutting state in the X direction. Further, when the direction of the electric current is reversed, the cutting edge C of the cutter blade 18 is reversed in the 0 ° direction, and the cutting state in the -X direction is established. Similarly, when a current is passed from the terminals b1 to b2, the line segment in the Y direction can be cut,
If the current is reversed, it is possible to cut in the -Y direction.

FIG. 3 shows the arrangement of the photosensors 25, 26 and 31, which are arranged at three 90 ° intervals. Two reflectors 19 and 20 are fixed to the cutter 17 with different mounting angles of 90 °. In addition, in the lower part of the outer cylinder 13, through holes 32, 3 are provided facing the photo sensors 25, 26, 31.
2, 32 are formed so that the reflection plates 19 and 20 can emit light and receive the reflected light.

Here, the reflectors 19 and 20 are rotated 90 ° and 180 ° counterclockwise with respect to the magnet 21, as shown in FIG.
FIG. 4 shows the relationship between the rotational position of the cutter 17 and the detection signals of the photosensors 25, 31, 26 when mounted at an angle of. If the outputs of the three photosensors 25, 26, 31 are regarded as 3-bit signals, as shown in FIG.
It is 011 at 10, 90 °, 001 at 180 °, 100 at 270 °, and 000 outside these angles.

This 3-bit signal is input to the drive control unit of the cutter head 11 described later to detect whether or not the direction of the cutter 17 matches the designated reference position. Next, referring to FIG. 5, the reference directions (0 °, 90 °, 180 °, 2
A procedure of generating a drive signal for controlling the direction of the cutter blade 17 to 70 ° will be described. In the figure, α is the first line segment, β
Is the second line segment, and the arrow indicates the cutting direction. Further, θ1 is an angle formed by the reference direction 0 ° and the second line segment β, and θ2 is an angle formed by an extension line (shown by a broken line) of the first line segment α and the second line segment β. Is.

First, the direction segment A2 of the second line segment β in the 45 ° equal-interval segments 0, 1, ... A2 = INTEGER (θ1 / 45) (Equation 1) The reference direction segment B2 = 0, 1, 2, 3 of the second line segment β is obtained from A2 obtained by integerization.

B2 = INTEGER ((A2 + 1) / 2) MODULO 4 ... Equation 2 The calculated reference direction divisions B2 of 0, 1, 2 and 3 are 0, 90 °, 180 ° and 270 ° of reference direction angles. Each corresponds. For example, when A2 = 7, from equation 2, ((7 + 1) / 2) / 4 = 1 ... remainder 0 Therefore, B2 = 0, and the reference direction angle is 0 °.

Next, a method of controlling the cutter head 11 will be described with reference to the flowcharts of FIGS. 6 and 7 and the operation explanatory diagram of FIG. In FIG. 8, P1, P2, ... Are cutter blades 1.
8 shows the center of rotation, and C1, C2, ... Show the positions of the cutting edges C. When the cutting command is input (step 101), the direction of the cutter blade 18 in the standby state (raised position) is indefinite, so the coils 22, 23, 2 shown in FIG.
By energizing the electromagnetic drive mechanism by 7, 28, the directions P1, C1 of the cutter blade 18 are changed to the reference direction P closest to the line segment α.
It is rotated to 1, C2 (step 102). The reference direction is determined by the procedure shown in FIG. Here, the line segment α is regarded as the line segment to be cut next, and is treated as the second line segment.

Then, in order to position the cutting edge C at the starting point S of the target line segment α, the cutter head 11 is moved to move the cutter blade 18 to P2 and C3 (step 103), and the cutter head 11 is lowered to move the cutting edge. Ground C (step 104). Then, the energization of the electromagnetic drive mechanism is cut off, the rotation of the cutter blade 18 is set to the free state, and the direction θ1 of the line segment α is
If does not match the selected reference angle B2, the process proceeds from step 105 to 106, and the rotation center P on the reference direction line
Is moved in an arc with C3 as a fulcrum and the eccentric amount D of the cutting edge C and the rotation axis P as a radius, and moves on the line segment α (P3, C
3) Let it go. Therefore, the rotation angle of the cutter blade 18 is B
It becomes 2 × 90 ° −θ1 and does not exceed 45 °.
If θ1 coincides with the reference angle, the process proceeds from step 105 to step 107 without performing the circular arc motion. In step 107, the XY drive control unit drives the cutter head 11, the line segment α is cut, and after moving the line segment length, it stops at P4 and C4.

If there is no other continuous line segment connected to the line segment α for which the cutting process has been completed, steps 108 to 10
In step 9, the cutter head 11 is raised and moved to the next line segment start position or standby position. If there is another continuous line segment β, the intersection angle θ2 with the extension line of the immediately preceding line segment α is determined (step 110). If θ2 is 45 ° or more,
That is, when the rotation angle of the cutter blade 18 is 45 ° or more, the cutter head 11 is raised to separate the cutting edge C from the cutting material (step 111). And
Returning to step 102, the cutter blade 18 is rotated to the P4 and C5 positions based on the reference direction determining procedure described above. Hereinafter, in step 103, the cutter head 11 is moved down to the P5 and C4 positions and is lowered (step 10
4), in the example shown in FIG. 8, the line segment β is cut into P6 and C4 in the process of step 106 in the next stage (step 10).
7).

Although not shown, when the intersection angle of the two line segments is less than 45 °, steps 110 to 112 are performed.
Similarly to the prior art, the rotary shaft P moves from the extension line of the immediately preceding line segment to the next target line segment by an arc motion centering on the cutting edge C and having the eccentric amount D as a radius, and proceeds to the cutting process. .. As described above, when the angle between the immediately preceding line segment and the next target line segment that follows the line segment is equal to or greater than a predetermined angle (here, 45 °), the cutter head 11 is once raised to change the direction of the cutter blade 18. After rotating to the reference angle closest to the direction of the target line segment, the blade tip is lowered to the start position of the next target line segment, the direction of the cutter blade 18 is aligned with the direction of the next line segment, and cutting is started. Therefore, in the case where the reference angle of this embodiment is set at 90 ° intervals, the angle at which the blade edge penetrating the pressure sensitive adhesive sheet material rotates to pry the pressure sensitive adhesive sheet material at the time of cutting is 45 ° at the maximum.
It can be suppressed to the following, and the deformation and damage of the cutting material in the bent portion of the line segment can be prevented.

Further, when the line segment data to be cut out is a sign sheet or the like of square Gothic characters, the cutting direction of the line segment is often a right angle direction, and therefore it is not necessary to perform an arc motion and no twisting occurs. As a result, the corner finish is improved. The present invention is not limited to the above-described embodiment, but the number of divisions of the circumferential section B2 by the cutter head rotating mechanism can be set variously, and the present invention extends to those modified. Is natural.

[0022]

Since the present invention is configured as described in detail in the above-mentioned embodiment, the amount of twisting of the cutting material by the cutting edge at the starting point and the bending point of the line segment can be reduced as much as possible. Therefore, the accuracy of cutting is improved and a high quality finish can be obtained. Further, since the corners of the pressure-sensitive adhesive sheet or the like are hardly deformed due to kinking, the fear of a decrease in the adhesive strength due to the deformation can be eliminated, and the quality and durability of the cut product can be improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cutter head used in a control method of the present invention.

FIG. 2 is a view taken along the line AA of FIG.

FIG. 3 is a view taken along the line BB of FIG.

FIG. 4 is a correspondence table between the direction of the cutter blade and the output of the photo sensor.

FIG. 5 is a chart used in a calculation formula for determining a reference angle.

FIG. 6 is the first half of a flowchart for controlling the direction of a cutter blade.

7 is the second half of the flowchart in FIG.

FIG. 8 is an explanatory diagram showing a trajectory of a cutter blade.

FIG. 9 is an explanatory diagram of a conventional cutting method.

[Explanation of symbols]

 11 Cutter Head 14 Cutter Holder 17 Cutter 18 Cutter Blade 19,20 Reflector 21 Magnet 22,23,27,28 Coil 25,26,31 Photosensor α, β Line Segment C Blade Edge P Rotation Center

Claims (1)

[Claims] 1. A cutting plotter that rotatably mounts a cutter on a cutter head, decenters the blade edge of the cutter with respect to its rotation center, and causes the blade edge to follow the movement of the cutter head to cut the cutting material. In this case, a drive means for rotating the direction of the cutting edge viewed from the rotation center of the cutter in a plurality of preset reference directions is provided, and when cutting two continuous line segments, the cutter is cut at the end point of the first line segment. The head is raised, and at the raised position, the direction of the blade edge of the cutter is rotated by the driving means to the reference direction closest to the second line segment, and the starting point of the second line segment and the blade edge of the cutter are aligned. The cutter head is moved, then the cutter head is lowered, and at the lowered position, the center of rotation of the cutter is centered on the blade edge of the cutter. Then, the cutter head is controlled so as to be moved from the reference direction line to the second line segment by an arc motion having the eccentricity as a radius to match the direction of the cutter with the direction of the second line segment. Cutter head control method for cutting plotter.