JPS61132396A - Lead-less detector for automatic drawing machine - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention is a method for controlling the elevation of a recording pen with a built-in lead automatic feeding mechanism with respect to a drawing surface.

The present invention relates to a coreless detection device that generates a coreless signal when the recording pen is held at a constant distance from a drawing surface and is consumed by a predetermined amount.

[Conventional technology]

In an automatic drawing machine that uses a consumable writing lead such as a lead lead, it is conventional to feed the lead onto the drawing surface as it wears down during drawing operations.

As disclosed in Japanese Patent Publication No. 58-54677, a push shaft movably disposed on a single drawing head is pressed against the core, and the core is pushed onto the printing surface according to the amount of wear on the core.

In such a configuration, if the lead decreases to the point where it is no longer suitable for drawing, the protrusion that interlocks with the push shaft collides with the limit switch provided on the printing head board, and the lead is turned off by the limit switch's input signal. It is configured to detect a state of wear that is unsuitable for drawing, that is, a state of no core.

[Problem that the invention seeks to solve]

However, recently, a recording pen with a built-in automatic lead feeding mechanism has been developed. If this recording pen is held in the drawing head of an automatic drafting machine so that it can be raised and lowered over 5 drawing screens, and the recording pen is controlled up and down with respect to the drawing surfaces, automatic drawing can be performed without using the push shaft mentioned above. becomes. In this case, during one drawing, if the lead in the recording pen becomes short due to wear and becomes unsuitable for drawing, the line becomes blurred, and as soon as the line is drawn, the movement of the drawing head is controlled in that state. Become. The problem is how to detect this coreless state.

The present invention is an automatic drafting machine that uses a recording pen with a built-in lead automatic feeding mechanism, which detects when the lead in the recording pen decreases and becomes short to a predetermined size, and outputs a leadless signal. The object of the present invention is to provide a coreless detection device.

[Means to solve problems]

In order to achieve the above object, the present invention prevents the upward movement of the consumable writing lead 46 with respect to the holder tube 40, and
The core 46
A lead chuck 48,50 disposed in the holder tube 40 that clamps the holder tube 40 protrudes elastically by a predetermined amount below the holder tube 40, so that when the holder tube 40 is lowered relative to the drawing surface, the lower end The core 46 is in contact with the drawing surface and is spaced from the core chuck 48, 50 by a predetermined distance below.
is slidably held with a predetermined frictional force, and when the holder cylinder 40 is raised to a predetermined position with respect to the drawing surface by a pen up signal from the controller, the lead 46 is held in the lead chuck 48.50. A lead holding tube 56 is provided to let out the lead 46 in the downward direction by the amount of wear until the pen-up signal.

A recording pen 1 having a built-in automatic lead feeding mechanism in which movement of the lead 46 in the upward direction with respect to the holder tube 40 is stopped by the lower end surface of the lead chuck 48, 50.
The holder tube 40 of No. 8 is lowered by the driving force of the solenoid 24 built into the printing head 8 in response to a pen down signal from the controller until the lower end of the lead 46 comes into pressure contact with the printing surface, and in this lowered state, the printing head 8 In an automatic drawing machine in which a predetermined drawing is performed by controlling the movement of the core holding tube 56 relative to the drawing surface according to instructions from a controller, the core holding tube 56 is at its lowest position with respect to the holder tube 40. 56 and the upper end of the core chuck 48.
50 and the lower end thereof is set to be longer than the wear length of the lead 46 during a preset pen-down state duration time, and the lead chuck 48,50 and the lead 46 are connected so that current flows between them. When connected to a power supply circuit and the recording pen is lowered, the lead chuck 48.50
A core presence/absence detector 39 is provided which operates when the contact pressure of the upper end of the core 46 with respect to the lower end decreases and the above-mentioned current value decreases below a set value. First, the initial position is set so that the lower end of the lead 46 and the lower end of the lead holding tube 56 exactly match when the lead holding tube 56 is at the lowest position with respect to the holder tube 40. When the holder tube 40 is lowered by the biasing force of the solenoid 24 at the initial position of the core described above, the lower end of the core 46 collides with the drawing surface, thereby stopping the descent of the holder tube 40, and the lower end of the core 46 is It is pressed against the drawing surface with a pressure determined by the excitation force of the solenoid 24. Next, the drawing head 8 is driven by the controller and moves relative to the drawing surface while maintaining a constant distance from the drawing surface, whereby a predetermined drawing is performed on the drawing surface. During this drawing, the holder tube 40 is moved in the downward direction by the excitation force of the solenoid 24 as the core 46 decreases, and the pressure 8 is maintained constant. At this time, as the number of leads 46 decreases, the lead holding tube 56 rises with respect to the holder cylinder 40 due to the pressure from the cutting surface, and the upper end of the lead holding tube 5.6 approaches the lower end of the lead chuck 48.50. 6. When the preset pen-down state duration time has elapsed, the holder cylinder 40 is raised to a predetermined position relative to the drawing surface according to a command from the controller. At this time, the core holding tube 56 is lowered to the lowest position with respect to the holder tube 40 by the amount that it has risen relative to the holder tube 40 according to the decrease in the core 46, and the core 46 is lowered to the lowest position with respect to the holder tube 40. In conjunction with the lowering, the lead 46 is lowered relative to the lead chuck 48.50, and the lead 46 is paid out from the lead chuck 48.50 in the downward direction by the amount of the decrease. When the recording pen 18 is raised and lowered a plurality of times, the lead 46 gradually becomes shorter, and finally the lead 46 is separated from the lead chuck 48, 50. In this state, when the holder @40 is lowered relative to the work surface, the upper end of the lead 46 is locked by the lower end of the lead chuck 48, 50, and this locking action applies a predetermined pressure of 8 to the work surface. In other words, the holder cylinder 40 due to the excitation force of the solenoid 24
The downward force on the drawing surface is received by the lower surface of the core chuck 48, 50. When the holder cylinder 40 is moved up and down at regular intervals with the lead 46 detached from the lead chuck 48, 50 as described above, as the number of leads 46 decreases, the holder cylinder 40 will be 48. Get closer to the first work screen than when you were held in the grip of 50. When the lead 46 is reduced to the same length as the lead holding tube 56, the lead 46 no longer protrudes from the upper end of the lead holding tube 56, the upper end of the lead holding tube 56 comes into pressure contact with the lower surface of the lead chuck 48, 50, and the lead is removed. The lower end of the holding tube 56 will be pressed against the working surface, and the lead 46 will no longer be able to receive pressure from the lead chuck 48,50. At this time, the core 46
Due to the reduction in contact pressure between the upper end and the core chuck 48.50,
The resistance value of the power supply circuit that flows current between the lead 46 and the lead chuck 48, 50 increases, and the current in this circuit decreases below the set value. Coreless information is output from 39.

〔Example〕

The structure of the present invention will be described below with reference to embodiments shown in the accompanying drawings.

In FIG. 4, 2 is the body of an X-Y plotter, and a Y rail 6 is disposed on a table 4 so as to be movable along the X coordinate axis direction, and a plotting head 8 is movably disposed on the Y rail 6. installed on. As shown in FIG. 4, the printing head 8 includes a pen holding frame 12 fixedly attached to the elevating body 10, and a pen holding arm 14 whose one end is biased in the direction of tape to the elevating body 10. A recording pen 18 having a built-in automatic lead feeding mechanism is detachably held in the pen holder 16. The elevating body 10 has a guide shaft 2 fixed to the base plate of the head 8.
0, and the elevating body 10 is urged upward by a coil spring 22. A solenoid 24 is fixed to the base plate of the head 8, and its output shaft faces a protrusion 10a formed on the elevating body 10.

The solenoid 24 is a CPU of a personal computer.
30 (see FIG. 5) to a solenoid driver 32 of the controller. 33 is a pen holding detector disposed on the elevating body 10, and is constituted by a limit switch. The Y rail 6 and the printing head 8 are linked to XY motors 34 and 36 controlled by a controller, and are moved to a predetermined position on the table 4 by these drives. 38 is a pen stocker in which a plurality of recording pens 18 are held.

When the drawing head 8 is moved to the empty holding part 38a of the pen stocker 38 and the pen holder 16 is positioned within the holding part 38a, and then the drawing head 8 is separated from the holding part 38a, the pen is removed. The recording pen 18 held in the pen holder 16 is transferred to the holding portion 38a by a known pen exchanger II (not shown) built in the stocker 38, and the pen is exchanged. Further, the drawing head 8 that does not hold the recording pen is moved to the holding part 38b of the pen stocker 38 that holds the recording pen, the pen holder 16 is positioned in the holding part 38b, and then the drawing head 8 is When the head 8 is separated from the holding part 38b, the recording pen held in the holding part 38b is held in the pen holder 16 of the drawing head 8 by the pen exchange mechanism, and the pen is replaced. There is.

Next, the internal structure of the recording pen will be explained with reference to FIG.

Reference numeral 40 denotes a holder tube made of an insulator 40a and a conductor 40b, and a guide tube 42 made of a conductor is fixed to the inner peripheral surface of the holder tube. Reference numeral 44 denotes a head block made of a conductive material, and an annular collar 44a is formed on the outer periphery of the head block 44, and the lower part of the block 44 is fixed to the upper part of the guide tube 42. A shaft hole is provided in the center of the block 44 to slidably hold a consumable writing lead 46 made of a conductive lead lead. A tapered surface 42a whose diameter increases downward is formed on the lower inner wall surface of the guide tube 42. Numeral 48 and 50 are core chucks made of a pair of conductors, and curved surfaces 43a and 50a are provided at the bottom of these so that the width of the core chucks 48 and 50 increases downward.
is formed. An insulating member is fixed to a portion of the lower end of the core chucks 48, 50 that receives a coil spring. The tapered surface 42a and the curved surfaces 48a, 50
A plurality of steel balls 52 are arranged between the a and the a. The pair of core chucks 48 and 50 are urged upward by the elastic force of the coil spring. Reference numeral 54 denotes a bottomed conductive cylinder fixed to the lower part of the holder cylinder 40, and the outer peripheral surface of the collar of a core holding tube 56 made of a conductive material is slidably fitted onto the inner peripheral surface of this. There is. The holding tube 56
The lower half of the cylindrical body 54 protrudes downward from a hole formed at the bottom of the cylindrical body 54 . A coil spring is compressed and disposed between the upper surface of the flange of the holding tube 56 and the lower surface of the core chuck 48,50. , 57 is an annular rubber body fixed to the upper end of the holding tube 56, and the diameter of the shaft hole of the rubber body 57 is formed to be slightly smaller than the diameter of the core 46.

A positive DC voltage is applied to the shaft hole of the block 44, the core chucks 48 and 50, and the conductor 40b made of five rubber bodies, so that a current flows between the core chuck 48.50 and the core 46. It is structured to flow. In FIG.

It is set to output the pen-up issue. This preset value determines the amount of wear of the core 46 in one drawing operation. 66.68.70 is an OR circuit. 80
is a current detector, and the core chuck 48.50 and the core 4
6 and is connected to the power supply circuit so as to detect the value of the current flowing through it. 82 is a comparison circuit, 84 is a current value setter, and 86 is an AND circuit, and these constitute the core presence/absence detector 39. One input terminal of the AND circuit 86 is connected to the CPU 30.
The pen-down signal of LL l 74 is input.

Next, the operation of this embodiment will be explained.

First, a new lead 46 is set in the recording pen 18. The amount of protrusion of the core 46 is set so that its lower end exactly coincides with the lower end of the core holding tube 56. Controller C:PU
When the pen down signal is output from driver 3
2 is driven, solenoid 24 is energized, and solenoid 2
4 rondo descends. Due to this.

The elevating body 10 descends, the recording pen 18 held in the pen holder 16 descends, and the tip of the lead 46 comes into elastic contact with both paper surfaces on the table 4 with a predetermined pressure due to the excitation force of the solenoid 24. When the core 46 comes into pressure contact with both papers, the core 46 tends to rise relative to the core chuck 48, 50 due to the pressure from both papers. When the core chuck 48.50 tries to rise, the steel balls 52 bite tightly between the curved surface 48a and the tapered surface 42a, and the chucks 48.48a are pressurized by the steel balls 52 in the direction of approaching each other. . This pressing force causes the core 46 to move between the chuck pieces 48 and 48.
Movement in the upward direction with respect to a is prevented. When the lower end of the core 46 comes into pressure contact with both sheets of paper on the table 4, that is, the drawing surface, the descent of the elevating body 10 is stopped. In the state where the core 46 is in pressure contact with both papers, the holding tube 56 is moved to the cylindrical body 5 as shown in FIG.
4, and the lower surface of the flange of the holding tube 56 is in elastic contact with the upper surface of the bottom wall of the cylindrical body 54. Next, C.P.
Pulses are supplied from U30 to the motor driver 62, which moves in a predetermined direction within the plane, and predetermined drawings are performed on both sheets of paper. During drawing, the lead 46 is held in the lead chuck 48. While fixed at '50, its tip wears out. As the tip of the lead 46 wears out, the elevating body 10 and the pen holder 16 are lowered by the excitation force of the solenoid 24, and the pressure between the lower end of the lead 46 and the drawing surface is maintained constant.

Due to the wear of the lower end of the core 46, the holding tube 56 rises relative to the cylinder 54 by the same amount as the amount of wear of the core 46 against the elasticity of the coil spring, and the lower end of the flange of the holding tube 56 rises. is separated from the upper surface of the bottom wall of the cylindrical body 54. The amount of wear of the core 46 in one process of drawing is converted into the number of pulses, and the number of pulses is
It is preset in the count circuit 64 in advance. Core 4
6 has worn out a predetermined amount, the count circuit 64 outputs a pen-up signal. When the driver 32 is driven by the pen-up signal and the power to the solenoid 24 is cut off, the elevating body 10 is raised to a predetermined position by the elastic force of the coil spring 22. This elevating body 10
As the recording pen 18 rises, the tip of the lead 46 moves away from the drawing surface. When the recording pen 18 rises, the holding tube 56 is moved relative to the cylindrical body 54 until the flange of the holding tube 56 is locked to the bottom wall of the cylindrical body 54 by the elastic force of the coil spring S1. to descend. This holding tube 5
The core 46, which is tightly fitted into the rubber body 57 due to the lowering of the cylindrical body 6 with respect to the cylinder body 54, is moved by the holding tube 5 due to the frictional force with the rubber body 57.
It descends in conjunction with 6. This lowering of the core 46 causes the core 46 to
6 is pulled in the downward direction relative to the chucks 48 and 50, but the direction of the pulling force on the core 46 is in the direction in which the clamping force of the chucks 48 and 50 is loosened, so the core 46 , by the amount of wear.

It slides between the chucks 48 and 50 in conjunction with the holding tube 56 and is drawn out downward. Note that when the count circuit 64 outputs a pen-up signal, this signal is input to the reset terminal of the count circuit 64 via the OR circuit 68, and the count circuit 64 is reset.

In this way, each pen-up operation causes the lead 46 to be drawn downward by the amount of wear. As the core 46 becomes shorter, the core 46 is removed from between the chucks 48 and 50, as shown in FIG. Due to the mutual guiding action of the coil springs, the core 4 is brought into contact with each other by the lower end surfaces of the chucks 48 and 50 in this contact state.
The upper end of 6 will be locked. The core 46 is the chuck 48
In the state where the lead 46 is held between 50° and 50°, or in the state where the lead 46 is shortened and the upper end of the lead 46 is pressed against the lower end of the chuck 48. This current value a is detected by a current detector 80 and supplied to a comparison circuit 82, where it is compared with a set value and if a>b, the comparison circuit 82 outputs On.

As shown in FIG. 3, the total length of the core 46 is reduced to about the same length as the total length of the core holding tube 56 including the rubber body 57, and the upper end of the core 46 is on the same plane as the upper end of the core holding tube 56. In this state, when the elevating body 10 is lowered by the excitation force of the solenoid 24 in response to a pen-down signal until the lower end of the lead 46 comes into contact with both paper surfaces, the upper end of the lead holding tube 56 and the lower end of the lead chuck 48, 50 are brought into contact with each other. The contact pressure between the lower end of the lead chuck 48, 50 and the upper end of the lead 46 is reduced. This decrease in contact pressure increases the resistance value of the current-carrying circuit of the core 46.
The current flowing through decreases to the value indicated by C in FIG. When the current value becomes less than the set value, the comparator circuit 82 outputs 1 to the CPU.
11 Outputs +l coreless signal. If the one-stroke head 8 is continued to be driven in the drawing direction in the state shown in FIG. The lower end no longer comes into pressure contact with the drawing surface, the drawing line becomes blurred, and after that, it becomes impossible to print a single drawing line. The no-pen signal from the detector 39 is sent to the CPU via the AND circuit 86, and the CPU receives this signal and stops the drawing head 8 according to a pre-stored program.

After that, a pen exchange signal is output. Based on this pen exchange signal, the recording pen 18 of the 0-print head 8 is automatically exchanged with a desired recording pen in the pen stocker 386. Furthermore, based on the no-pen signal from the detector 39, the CPU ,
A coreless alarm lamp may be lit, or a coreless alarm buzzer may be driven. Further, the automatic drafting machine may have a configuration in which the drawing surface is perpendicular to the floor surface, that is, a configuration in which FIG. 4 is a front view. Therefore, in the above specification, the expressions "ascend" and "descend" used are based on the drawing surface, and when the drawing surface is set vertically, movement approaching perpendicular to the drawing surface is descending and movement away from the drawing surface. This means that there is a rise.

〔effect〕

As described above, the present invention lowers a recording pen with a built-in lead automatic feeding mechanism to the drawing surface by the excitation force of the solenoid, and causes the consumable writing lead inside the recording pen to come into elastic contact with the drawing surface by the excitation force of the solenoid. Therefore, when the lead decreases due to wear, the recording pen moves toward the printing surface due to the excitation force of the solenoid, and when the pen moves down, the contact pressure between the lead chuck and the lead decreases, causing the flow of water through the lead. Since the lead presence/absence detector is configured to operate when the current decreases below a set value, it is possible to detect when the lead in the recording pen has worn out by a predetermined amount.

[Brief explanation of drawings]

The figures show preferred embodiments of the present invention.
8... Printing head, 10... Elevating body,
12... Pen holding frame, 14... Pen holding arm, 16... Pen holder. 18...Recording pen, 20...Guide shaft. 22...Coil spring, 24...Solenoid. 30...CPU, 32...Solenoid driver, 33...Pen holding detector, 34°36.
...Motor, 38...Pen stocker. 39... Core presence/absence detector, 40... Holder simple, 44... Head block, 42... Guide tube, 46... Core, 48.50... Core Chuck, 56...Core holding tube patent applicant Muto Kogyo Co., Ltd. - ゛2Representative patent attorney Ayao Nishijima:
2.) Figure 5 Figure 6

Claims (1)

[Scope of Claims] 1. The conductive consumable writing lead 46 is prevented from moving in the upward direction relative to the holder cylinder 40, and the lead 4 is prevented from moving in the downward direction relative to the holder cylinder 40.
A core chuck 48 disposed within the holder tube 40 that clamps the core 46 so that no fixing force is applied to the core 46.
, 50 elastically protrudes below the holder tube 40 by a predetermined amount, and when the holder tube 40 descends relative to the drawing surface, its lower end abuts the drawing surface and is spaced apart from the core chucks 48 and 50 by a predetermined distance. The lead 46 is held in a slidable manner with a predetermined frictional force at a distance below, and when the holder tube 40 is raised to a predetermined position relative to the drawing surface by a pen-up signal from the controller, the lead 46 A lead holding tube 56 that is fed out in a downward direction relative to the lead chucks 48 and 50 by the amount of wear of the lead 46 up to the pen-up signal.
When the lead 46 is released from the lead chucks 48 and 50 by feeding out the lead 46 in the downward direction, the lower end surfaces of the lead chucks 48 and 50 prevent the lead 46 from moving in the upward direction with respect to the holder tube 40. The holder tube 40 of the recording pen 18, which has a built-in automatic lead feeding mechanism that is locked, is moved to the drawing surface by the driving force of the solenoid 24 built into the printing head 8 in response to a pen down signal from the controller. In an automatic drawing machine, the drawing head 8 is lowered until it comes into pressure contact with the drawing surface, and in the lowered state, the drawing head 8 is controlled to move relative to the drawing surface according to instructions from a controller to perform a predetermined drawing. The upper end of the core holding tube 56 and the core chucks 48 and 50 at the lowermost position of the tube 56 relative to the holder tube 40
The opposing interval with the lower end of the lead chucks 48, 50 and the lead 46 is set to be longer than the wear length of the lead 46 during a preset pen-down state duration time, and the lead chucks 48, 50 and the lead 46 are connected so that current flows between them. connected to the power supply circuit, and the recording pen 18
In the lowered state, the core chucks 48, 50
A coreless detection device comprising a core presence/absence detector 39 that operates when the contact pressure of the upper end of the core 46 with respect to the lower end decreases and the current value decreases below a set value.