JP2594434B2 - Coreless detector for automatic drafting machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention controls a writing instrument having a built-in automatic lead-out mechanism to move up and down with respect to a screen, while maintaining the writing instrument at a constant interval with respect to the screen. The present invention relates to a coreless detecting device for detecting the timing of the lead-out of the writing implement and the state in which there is almost no residual core in the writing implement, in an automatic drafting machine configured to perform drawing by controlling the movement of the writing implement.

[Conventional technology]

The apparatus disclosed in Japanese Patent Application Laid-Open No. 61-132394 detects a centering timing by counting a preset pen-down state duration time, and detects a centerless signal to detect a descending position set by a writing instrument. It is made with a container.

The device disclosed in Japanese Patent Application Laid-Open No. 61-132395 detects the timing of centering by counting the pen down state duration set in advance, and detects a centerless signal from the upper end of the core holding tube in the writing instrument and the center chuck. It is created by the current flowing between the lower ends when they come into contact.

[Problems to be solved by the invention]

In the method of detecting the centering timing by counting the pen down state duration time, the wear speed of the core is not constant depending on the core used, so it is necessary to set the above time anew every time the core is replaced. , The operation is cumbersome,
In addition, a controller program for that purpose was not easy. Therefore, there is an apparatus that performs the centering operation detection and the centerless detection with one switch, but in that case, there is a problem of splicing.

As shown in FIG. 15, the stroke range of the writing instrument 12 is 1 to 2 mm in consideration of the flatness of the drawing board, variation in the dimensions of the writing instrument, and the like.
And Then, since the maximum value of the stroke is 2 mm, the maximum value of the stroke of the writing instrument 12 without the core as shown in FIGS. 6 and 7 is (2 + 1) mm. 1 is a slidable range of the core holding tube 86, that is, the pen tip. Therefore, when the writing tool descends and exceeds 2 mm, the state shown in FIGS. When writing a long line, the core 76 is scraped and the nib 86 slides, and the writing implement gradually descends.
If the pen tip 86 slides 3 mm with respect to the holder cylinder 70 of the writing implement 12, drawing cannot be performed. Therefore, before this state is reached, the writing implement must be raised, and the lead 76 must be projected in the protruding direction by operating the lead automatic feeding mechanism incorporated in the writing implement 12. The position of the detector for performing the centering operation must be below (minimum stroke + 3 mm) from the writing implement ascending position. Under the above conditions, the position of the detector must be 4 mm or less, and preferably 3 to 3.5 mm with a slight margin. When the centering operation detection and the centerless detection are performed by one detector, the detectors are arranged so as to detect a point where the writing implement is lowered 3.5 mm from the ascending position. During drawing, the controller recognizes the centering when the 3.5 mm writing implement is lowered with respect to the ascending position and performs the centering operation.When the writing implement is lowered, it recognizes that there is no center when the 3.5 mm writing implement is lowered, and replaces the writing implement. . Here, when the writing implement descends, there is no core when it exceeds 2 mm, so the writing implement is 3.5
You don't have to wait until it drops to mm. However, since the waiting time of the writing implement is set to the time required for the writing implement to descend by 3.5 mm, the drawing efficiency deteriorates. In this case, even if there is a lead, the motor for moving the drawing head 6 is started after the waiting time has elapsed. Therefore, the drawing processing time as a whole becomes long. Accordingly, an object of the present invention is to increase the drawing efficiency by causing the controller to separately recognize the centering operation detection position and the centerless detection position based on the signal of a single position sensor.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a drawing head that can be controlled to move in the horizontal direction with respect to the drawing surface, a writing tool holder that can be driven in a direction substantially perpendicular to the drawing surface, and Controlled by the controller, the writing implement held in the writing implement holder is configured to be controlled to move up and down in a direction substantially perpendicular to the drawing surface, and the drawing head is provided with a position sensor for detecting the elevation position of the writing implement holder, The writing instrument, the holder tube, the consumable writing lead is prevented from moving in the ascending direction with respect to the holder tube, and the core is so fixed that the fixing force to the core does not act on the movement of the core in the descent direction with respect to the holder tube. A core chuck disposed in the holder cylinder for holding the holder, and a predetermined amount of elastically protruding below the holder cylinder slidably in the holder cylinder within a predetermined range. An automatic drafting machine comprising a core holding tube for holding the core slidably with a predetermined frictional force at a predetermined distance below the core chuck, wherein the lowering position of the writing instrument holder is set in advance to a first position. And a centering signal generating circuit that outputs a centering signal based on the output of the position sensor when the lowering position of the writing instrument holder reaches a preset second setting position. A coreless signal generation circuit that outputs a coreless signal based on the output of the sensor is provided, and the circuit is connected to the controller, and the controller outputs the signal when the centering signal is output during drawing. When the writing tool lowers, the signal indicating no core is output, and when the writing signal is output, it is recognized that the writing tool has lost its core.

[Action]

In the above-described configuration, the initial position of the new long core 76 is set in advance so that the tip thereof exactly matches the lower end of the core holding tube 86. In the above initial position of the lead, the writing implement
When the 12 is lowered, the tip of the lead 76 collides with the drawing screen, whereby the lowering of the writing implement 12 is stopped, and the lower end of the lead 76 is pressed against the drawing screen. Next, the drawing head 6 is driven by the controller and moves with respect to the drawing while maintaining a certain interval with respect to the drawing, whereby a predetermined drawing is performed on the drawing. During this drawing, the holder cylinder 70 moves in the descending direction by the descending force in accordance with the decrease of the core 76, and the core pressure is maintained. At this time, the core holding tube 86 rises with respect to the holder cylinder 70 by the pressure from the screen according to the decrease of the core 76, and the upper end of the core holding tube 86 approaches the lower ends of the core chucks 78 and 80. Before the upper end of the core holding tube 86 comes into contact with the lower ends of the new chucks 78 and 80, the writing implement 12 reaches the first set position,
The centering signal generation circuit generates a centering signal. When this signal is output, the holder cylinder 70 moves up to a predetermined position with respect to the screen at the next stop position of the drawing head 6 according to a command from the controller. At this time, the core holding tube 86 is lowered to the lowest position with respect to the holder tube 70 by the amount raised with respect to the holder tube 70 in accordance with the decrease amount of the core 76, and the core 76 is In conjunction with the lowering, the lead is lowered with respect to the lead chucks 78 and 80, and the lead 76 is fed from the lead chucks 78 and 80 in the descending direction by the reduced amount. When such a lifting operation of the writing instrument 12 is performed a plurality of times, the lead 76 is gradually shortened, and eventually, the lead 76 is detached from the lead chucks 78 and 80. In this state, when the holder cylinder 70 descends with respect to the screen,
The upper end of the core 76 is locked by the lower ends of the core chucks 78 and 80,
A predetermined core pressure is applied to the screen by this locking action. That is, the lowering force of the holder cylinder 70 on the screen is received on the lower surfaces of the core chucks 78 and 80. Wick 76 as above
Is released from the core chucks 78 and 80, and the holder cylinder 70 is
When the ascent / descent operation for centering is performed,
The holder cylinder 70 comes closer to the screen than when the lead 76 is held between the lead chucks 78 and 80. In this state, when the writing implement 12 is lowered, the writing implement 12 is lowered to the second set position, and the coreless signal generating circuit outputs a coreless signal. When the controller recognizes the coreless signal when the writing implement descends, the controller shifts to the writing implement replacement operation.

〔Example〕

Hereinafter, the configuration of the present invention will be described in detail with reference to embodiments shown in the accompanying drawings.

First, the outline of the configuration of the automatic drafting machine will be described with reference to FIGS.

Reference numeral 2 denotes a Y supported to be movable on the drawing board 4 in the X coordinate axis direction.
A rail, on which a Y cursor (not shown) is movably connected, and a drawing head 6 is connected to the Y cursor. A plurality of writing tools 12 are detachably held in a writing tool stocker 10 provided in the main body 8 of the automatic drafting machine. An elevating member 16 is mounted on a substrate 14 of the head 6 by a guide shaft.
The elevating member supported so as to be able to move up and down along 17,17a
16 is provided with a writing instrument holder 18 having a moving arm 20. A moving coil 24 is fixed to the coil holder 22 attached to the elevating member 16, and the moving coil 24 is provided with a field constituting unit 26 disposed on the substrate 14.
Facing. When the moving coil 24 is in the non-excited state, the elevating member 16 is configured to rise by the elastic force of the return spring 28 until its upper end is locked by the upper limit stopper 30 fixed to the substrate 14. Reference numeral 32 denotes a position sensor, which includes a light source 34, a light receiving element 36, and a shielding plate 38 as constituent elements. The shielding plate 38 is fixed to the elevating member 16. The light receiving element 36 and an electronic circuit unit built in the casing of the sensor 32 constitute a position-voltage converter 40. When the X motor 40 is driven, the Y rail 2 moves in parallel in the X coordinate axis direction along the drawing board 4, and when the Y motor 42 is driven, the Y cursor moves along the Y rail 2. It is configured to be. The XY motors 40 and 42 are connected to a central processing unit (CPU) via XY motor drivers 44 and 46 as shown in FIG. The moving coil 24 is connected to the CPU 48 via a pen-up / down driver 50 and a digital / analog converter 52, and the position-voltage converter 40 is connected to the CPU 48 via an analog / digital converter 54. ing. A drawing program is stored in a ROM (read only memory) 56. 2, 58 is a ROM, 60 is a RAM (random access memory), 62 is an EEPROM (an electrically readable / writable ROM), 64 is a centering and coreless signal generation circuit, and 66 is a panel operation. Reference numeral 68 denotes an input / output device.

The automatic drafting machine has a writing tool automatic exchange function.
The XY motors 40 and 42 are driven by the control of the CPU 48, and the head 6 is positioned in front of the desired holding unit, for example, the holding unit of No. 1 in FIG. 3 among the plurality of holding units of the writing instrument stocker 10. From the position, the head 6 is moved in a linear direction until the holder 18 is fitted to the writing implement of the NO. 1 holding part on the stocker 10 side. The writing implement holder 18 of the head 6 is the writing implement of the NO.1 holding part.
Arriving at 12, and fitting with the writing instrument, the writing instrument stocker
The writing tool 12 held by the writing tool 10 is held by both the writing tool stocker 10 and the writing tool holder 18 of the head 6. next,
When the head 6 is moved linearly in a direction away from the stocker 10 to a predetermined position, the writing implement 12 held by the NO.1 holding part of the stocker 10 is detached from the holding part of the NO. Is held only by the writing implement holder 18 of the head 6, as shown in FIG. In this state, the flange 12a of the writing implement 12 fits into the groove 18a of the holder 18, and the writing implement 12
Vertical movement of the holder 12 with respect to the holder 18 is prevented,
In addition, the movement of the writing instrument 12 in the direction perpendicular to the longitudinal direction of the writing instrument 12 with respect to the holder 18 is prevented by the elastic holding force of the moving arm 20 constituting the holder 18.

Next, the internal structure of the writing instrument 12 will be described with reference to FIG.

Reference numeral 70 denotes a holder tube, and a guide tube 72 is fixed to the inner peripheral surface of the holder tube. Reference numeral 74 denotes a head block having an annular flange 12a formed on the outer periphery thereof, and a lower portion of the block 74 fixed to an upper portion of the guide cylinder 72. A shaft hole for slidably holding a writing consumable lead 76 made of a lead core is in contact with the center of the block 74. Guide tube 72
Tapered surface 72a that expands downward on the lower inner wall surface of
Are formed. 78 and 80 are a pair of core chucks,
Curved surfaces 78a, 80a are formed below these so that the lateral widths of the core chucks 78, 80 increase downward. A plurality of steel balls 82 are provided between the tapered surface 72a and the curved surface 78a.
Is arranged. The pair of lead chucks 78 and 80 are urged upward by the resilient force of a coil spring. Reference numeral 84 denotes a bottomed cylindrical body fixed to the lower portion of the holder cylinder 70, and the outer peripheral surface of the flange portion of the core holding tube 86 is slidably fitted to the inner peripheral surface thereof. The lower half of the holding tube 86 projects downward from a hole formed in the bottom of the cylindrical body 84. The upper surface of the flange of the holding tube 86 and the core chuck 7
A coil spring is arranged in compression between the lower surface of 8,80. Numeral 88 denotes a friction body made of an annular rubber body, which is fixed to the upper end of the holding tube 86, and the diameter of the shaft hole of the friction body 88 is
The diameter is slightly smaller than the diameter of 76. The block
One core 76 is inserted and arranged in the shaft hole 74, the core chucks 78 and 80, the shaft hole of the friction body 88, and the holding tube 86.

In this embodiment, the sliding range of the core holding tube 86 with respect to the cylinder 84 is set to 3 mm.

 Next, the raising and lowering operation of the writing implement will be described.

When the pen-up / down driver 50 outputs a positive current to the moving coil 24 according to a command from the CPU 48, a descending force acts on the moving coil 24, and the elevating member 16
Descends against the elasticity of Pen up down driver
When a negative current from 50 is applied to the moving coil 24, an electromagnetic force acts on the moving coil 24 in the ascending direction.

When the lifting member 16 moves up and down with respect to the drawing board 4, the shielding plate 38
Moves up and down, and the amount of light irradiated on the light receiving element 36 changes.
The amount of light applied to the light receiving element 36 is output as a voltage signal from an output line 40a of the position-voltage converter 40 shown in FIG. This voltage signal is converted into a digital signal by the A / D converter 54 and supplied to the CPU 48. The CPU 48, based on the digital signal from the converter 54,
That is, the amount of movement of the writing implement holder 18 in the downward or upward direction and the height position are recognized.

The centering and centerless signal generation circuit 64 includes a pair of comparators 90 and 92, as shown in FIG. 1. One input terminal of each of the comparators 90 and 92 is connected to the position voltage-conversion circuit. It is connected to the output end of the vessel 40. Wherein the other input terminal of the comparator 90, the reference voltages V ₁ for out centering signal Concrete is applied to the other input terminal of the comparator 92, the reference voltage V ₂ for output no signal forming core Is applied. In the present embodiment, the distance from the set rising position of the writing implement 12 to the landing on the screen, that is, the pen stroke range, is determined by the flatness of the drawing board 4 and the accuracy of the writing implement 12, that is, the flange 12
The length is set to 1 to 2 mm in consideration of variations in the length S between the lower surface of a and the tip of the core holding tube 86. The reference voltages V ₁ is set to a voltage corresponding to pen stroke 3.5 mm, the reference voltage V ₂ is set to a voltage corresponding to pen stroke 2.1 mm. The comparator 90, the input voltage VE1 reference voltages V ₁
When the VE1 ≧ V ₁ with respect to output a centering signal, the comparator 92 outputs a centerless signal when the input voltage VE2 is VE2 ≧ V ₂ with respect to the reference voltage V _2.

Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG.

In the determination block 100, the CPU 48 determines whether or not the writing implement 12 held by the writing implement holder 18 of the head 6 is a pencil. In this pen type determination, a coded mark indicating the type is attached to the writing implement, the mark is read by a mark reader provided on the head 6, and the CPU 48 makes a determination based on an output signal of the reader. If the writing implement is a pencil, the CPU 48 sets a constant a indicating the number of centering (that is, the writing implement lowering operation) in the RAM 60 to zero (block
106). Next, the CPU 48 supplies the pen-down control current 102 shown in FIG. 15 to the moving coil 24 of the head 6 to lower the writing implement 12 (block 108). When the wick 76 is pressed against the drawing paper 104 on the drawing board 4, the wick 76 tends to rise relatively to the wick chucks 78 and 80 due to the pressure from the drawing paper 104. When the core 76 is going to rise, the steel balls 82 bite tightly between the curved surface 78a and the tapered surface 72a, and the chucks 78, 78a are pressed by the steel balls 82 in a direction approaching each other. . The core 76 is chucked by this pressure.
Movement in the upward direction relative to 78, 78a is prevented. Wick 76
When the lower end is pressed against the drawing paper 104 on the drawing board 4, that is, the screen, the lowering of the elevating member 16 stops. In a state where the core 76 is pressed against the drawing paper 104, the holding tube 86 is, as shown in FIG.
The lower surface of the flange of the holding tube 86 is in elastic contact with the upper surface of the bottom wall of the cylindrical body 84. After the writing implement 12 begins to descend, the writing implement 12 lands on the paper 104 on the drafting board 4,
When a predetermined waiting time considering the time required for stabilization has elapsed (block 110), the CPU 48 determines whether or not a coreless signal is output from the comparator 90 (block 11).
2). If YES, the CPU 48 supplies a pen-up current signal to the moving coil 24 to raise the writing implement 12 to the set position (block 114). Next, the CPU 48 determines whether or not a = 1 (block 116).
Is added, and a = a + 1 is set (block 118), and the process returns to block 106. If YES, the head 6 is a writing instrument holder
The writing implement 12 held at 18 is returned to a predetermined holding section of the writing implement stocker 10 (block 120). Next, the CPU 48
Based on the read signal of the pen type reading device provided in each holding unit of the writing implement stocker 10 or the pen type data of each holding unit read in advance by the reading device of the head 6, the writing implement stocker 10 can be moved to the writing implement stocker 10. Determine if there is a pen or pencil (block 122);
A buzzer sounds to indicate that there is no writing instrument (block 124). Next, the CPU 48 determines in a determination block 126 whether or not the holding part of the writing implement stocker 10 holds the pencil. If YES, the head 6 goes to get the same kind pen of the writing implement stocker 10 and holds it. (Block 128),
Thereafter, the process returns to block 106. CPU48 is the judgment block
If NO is determined in 112, the CPU 48 sets a = 0 (block 130), and then starts the XY motors 40 and 42 (block 132), and executes one process of drawing on paper by the head 6. I do. During drawing, the tip of the lead 76 is worn down while being fixed to the lead chucks 78 and 80. With the abrasion of the tip of the core 76, the elevating member 16 and the holder 18 are lowered by the exciting force of the moving coil 24, and the pressure on the lower end of the core 76 and the screen is kept constant. The wear of the holding tube 86
Rises relative to the cylindrical body 84 by the same amount as the amount of wear of the core 76 against the elasticity of the coil spring, and the lower surface of the flange of the holding tube 86 becomes cylindrical as shown in FIG. Away from the top surface of the bottom wall. Next, when the printing of one process is completed, the XY motors 40 and 42 are stopped (block 134), and the CPU 48 determines whether or not the pen is up (block 136). If YES, perform a pen-up operation. Next, it is determined whether or not there is drawing data in the RAM 60 (block 138). If YES, the XY motors 40 and 42 are activated (block 140), and the head 6 is moved to the drawing start point in the next step. Thereafter, the XY motors 40 and 42 are stopped (block 142). Then, the process returns to block 108. Decision block 13
If 6 determines NO, the CPU 48 determines in a decision block 144 whether the comparator 90 of FIG. 1 is outputting a centering signal. If YES, a pen-up current signal is supplied to the moving coil 24 (block 146), and the lifting member 16
Is raised to a predetermined position. As the lifting member 16 rises, the writing implement 12 rises, and the tip of the lead 76 separates from the screen. When the writing instrument 12 is lifted, the holding tube 86 is moved by the elastic force of the coil spring S1 so that the flange of the holding tube 86 is cylindrical.
It descends relatively to the cylinder 84 until it is engaged with the bottom wall of the cylinder 84. As the holding tube 86 descends with respect to the cylinder 84, the core 76 closely fitted to the friction body 88 descends in conjunction with the holding tube 86 due to the frictional force with the friction body 88. When the lead 76 is lowered, the lead 76 is pulled in a descending direction relative to the chucks 78 and 80, but the pulling direction of the lead 76 is such that the tightening force of the chucks 78 and 80 is loosened. Wick 76 to work
The chuck 7 works in conjunction with the holding tube 86 by the amount of wear.
It slides between 8,80 and will be extended downward. Next, the CPU 48 sets a = a + 1 (block 148) and returns to block 108. If the decision block 144 determines NO,
The CPU 48 starts the XY motors 40 and 42 to perform drawing (block 150), and when the drawing of one process is completed, the XY motors 40 and 42 are started.
Stop 42 (block 152) and return to decision block 136. In this manner, image formation including a number of image formation steps is sequentially performed.

〔effect〕

According to the present invention, as described above, the controller can separately recognize the centering operation detection position and the centerless detection position of the writing implement based on the output of one position sensor, so that the waiting time for drawing can be reduced. There is an effect that the drawing efficiency can be improved.

[Brief description of the drawings]

1 is a block circuit explanatory diagram, FIG. 2 is a block circuit explanatory diagram, FIG. 3 is a plan view, FIG. 4 is a sectional view, FIG. 5 is a sectional view, FIG. 6 is a sectional view, and FIG. FIG. 8 is an explanatory view, FIG. 9 is an explanatory view, FIG. 10 is an electronic circuit diagram, and FIG.
FIG. 10 is an output characteristic diagram, FIG. 12 is a flowchart, FIG. 13 is a flowchart, FIG. 14 is a flowchart, and FIG. 15 is an explanatory diagram. 2 ... Y rail, 4 ... drawing board, 6 ... drawing head, 8 ... automatic drawing machine body, 10 ... writing implement stocker, 12 ... writing implement, 14
…… board, 16 …… elevating member, 18 …… writing instrument holder, 20…
… Moving arm, 22… coil holder, 24… moving coil, 26… field constituent part, 28… return spring, 30… upper limit stopper, 32… position sensor, 34… light source, 36… Light receiving element, 38 ... Shielding plate, 40 ... X motor, 42 ... Y motor,
44, 46 …… Motor driver, 48 …… Central processing unit (CPU),
50 …… Pen up / down driver, 70 …… Holder tube,
72 …… Guide tube, 72a …… Tapered surface, 74 …… Head block,
76 …… Core, 78,80 …… Core chuck, 78a, 80a …… Curved surface, 82…
… Steel ball, 84 …… Cylinder, 86 …… Core holding tube, 88 …… Friction body, 102
…… Pen down control current, 104 …… Drawing paper

Claims (3)

(57) [Claims] A writing head capable of being driven in a direction substantially perpendicular to the drawing surface is provided on a drawing head that can be controlled to move in the horizontal direction with respect to the drawing surface, and the writing tool holder is controlled by a controller. The writing implement held in the writing implement holder is controlled to rise and fall in a direction substantially perpendicular to the drawing surface, and the drawing head is provided with a position sensor for detecting the elevation position of the writing implement holder. A holder for holding the lead so as to prevent movement of the consumable writing lead with respect to the holder tube in the upward direction and prevent the fixing force on the lead from acting on the downward movement of the lead with respect to the holder tube; A core chuck disposed in the cylinder, and a predetermined amount of elastically protruding below the holder cylinder slidably in the holder cylinder within a predetermined range and projecting from the core chuck by a predetermined amount. A lowering position of the writing instrument holder is set to a first set position set in advance in an automatic drafting machine comprising a wick holding tube for slidably holding the wick with a predetermined frictional force below the isolated portion. When it reaches, the centering signal generating circuit that outputs a centering signal based on the output of the position sensor, and when the descending position of the writing instrument holder reaches a second set position set in advance, the output of the position sensor is output. A coreless signal generation circuit that outputs a coreless signal based on
The circuit is connected to the controller, and the controller recognizes a decrease in a predetermined amount of the wick by the signal when the centering signal is output during drawing, and the coreless signal is output when the writing implement descends. A leadless detecting device configured to recognize that the lead in the writing instrument has disappeared when the signal is received. 2. The first set position is set to a minimum value of a descending amount when the writing implement is lowered from its raised position until the tip of the lead holding tube reaches a drawing screen. 2. The automatic drawing according to claim 1, wherein the writing implement is set at a position where the writing instrument is lowered from the ascending position by a distance close to the reference value that is equal to or less than the reference value, based on a value obtained by adding a slidable range amount to the holder cylinder. Machine coreless detector. 3. The writing device according to claim 2, wherein the second setting position is based on a maximum value of a descending amount when the writing implement is lowered from its raised position until the tip of the core holding tube reaches a screen. 2. The coreless detection device for an automatic drafting machine according to claim 1, wherein the position is lowered from an ascending position by an amount exceeding the maximum value.