JPH07215722A - Press molding equipment - Google Patents

Abstract

PURPOSE:To improve the dimensional accuracy of pressed products and to decrease defective articles by fixing ferromagnetic material members to metal molds of a press machine for molding glass and combining electromagnets, sensors and control mechanism, thereby executing alignment of the metal molds to each other or position adjustment of deviated weight correction. CONSTITUTION:Glass gob 11 is supplied to a metal mold die 12 and a metal mold punch 13 integrated with an armature 25 is floated by ejecting air from nozzles 22, 23. This punch 13 is lowered by a lifting pressurization mechanism 15 and the alignment of the punch 13 and the die 12 is executed by controlling the currents of 8 pieces of the electromagnets 21 from the time >=3 pieces of the gap sensors 24 descend down to the point where the measurement of the position of the die 12 is possible. The punch 13 is fixed to a frame 20 in contact therewith by stopping the air supply to the nozzle 23 and passing the currents to the electromagnets 26 after the end of the alignment. The punch 13 is lowered to pressurize the glass gob 11 by the lifting pressurization mechanism 15. The punch 13 is raised by the lifting pressurization mechanism 15 after the end of the pressing and the currents of the electromagnets 16 are decreased to zero.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a press machine for molding glass such as cathode ray tube panels and funnels by sandwiching a glass material or the like between a plurality of molds and applying a pressure to the mold. TECHNICAL FIELD The present invention relates to an apparatus and method for correcting biased weight of a pressing machine suitable for a process that requires a highly accurate pressure-controlled press.

[0002]

2. Description of the Related Art FIG. 6 shows an example of a typical layout using a conventional technique, for example, in the step of press molding glass. In addition, a typical example of a press machine and a mold for panel molding of a cathode ray tube used in this layout is shown in FIG.
Shown in. FIG. 6 shows a high temperature glass gob (molten glass) 11
It is the schematic diagram which looked at the place where the lower mold 12 on which is mounted is fixed on the rotary table 30 from above. For example, eight mold lower dies 12 are attached to the rotary table at equal intervals, and when the rotary table 30 rotates clockwise by 45 degrees, the glass gob 11 is supplied to the mold lower dies 12 at the loading position 31. , Press position 3
In step 2, the upper die 13 is lowered by a press machine, and the lower die 12, upper die 13 and barrel 1 are placed on the glass gob 11.
Pressure is applied at 4 to perform molding.

At this time, the positioning accuracy of the mold lower mold 12, the mold upper mold 13, and the mold barrel mold 14 is conventionally determined by the position of the press machine, the stop position of the rotary table 30, and the mold on the rotary table 30. It was determined by the mounting position of the lower die 12 and the assembly accuracy of the die lower die 12 and the die barrel die 14. Further, in order to improve the positioning accuracy, the upper die 13 and the lower die 1
In some cases, the key 16 and the key groove 17 are provided between the two or the mold body mold 14 to perform the key fitting.

Another example of a conventional glass pressing apparatus is shown in FIG.
Shown in. This conventional press machine is composed of a mold upper mold 151, a mold lower mold 152, a mold upper mold guide 155, and a mold upper mold lifting / pressurizing device 156. Mold upper die lifting pressurizing device 1
The glass gob 154 is sandwiched between the upper mold 151 and the lower mold 152 using 56, and pressure is applied to press-mold the glass.

[0005]

However, the following problems occur in the mold alignment of the conventional glass press shown in FIG.

(A) It is difficult to accurately attach a plurality of mold lower dies 12 to the rotary table 30 by a method that does not use key fitting. Even if it can be mounted with high accuracy in a relatively low temperature environment before the start of molding work, the positions of the respective lower mold dies 12 may vary in the high temperature environment during molding work. Even if the position of the upper die 13 of the pressing machine is adjusted, the dimension of the molded glass varies on the order of submillimeters.

(B) When the key fitting is used, it is possible to reduce the variation of the molded glass as compared with the case where it is not used, but the variation depends on the processing accuracy of the key 16 and the key groove 17. It is determined by the accuracy of attachment to the mold and the size of the fitting gap. With the current machine tool capabilities, it is necessary to ensure that the key and key groove machining accuracy and mounting accuracy of a large glass product in a mold are within a sub-millimeter order of error in a high temperature environment. Is technically difficult. In addition, since there is a rubbing portion in the key fitting, the key 16 or the key groove 17 is worn,
The alignment accuracy becomes worse. Further, the powder generated by the abrasion adheres to the glass, which may make the glass product defective.

(C) Further, since the dies cannot be sufficiently aligned with each other, the fitting between the dies must be loosened. For example, in FIG. 7, the fitting gap 18 between the upper die 13 and the upper die 14 is positioned between the upper die 13 and the upper die 14 so that the upper die 13 and the upper die 14 do not hit and damage each other. It must be larger than the alignment accuracy. When the fitting gap 18 is large, when a large force is applied as the press pressure, the glass protrudes from the fitting gap, and conversely,
If the pressing pressure is too low, there is a problem that the shape of the mold is not sufficiently transferred to the glass.

Further, the conventional press shown in FIG. 8 has the following problems.

(A) It is difficult to adjust the delicate pressure distribution at the time of pressing, which reduces the dimensional accuracy of the pressed product.

(B) In the pressing machine, backlash and flexure occur due to the upper die guide 155 while the die is moving or during pressing. The mold contacts the work at the start and end of pressing,
When separating, the pressing load applied to the whole is small, but due to the backlash and deflection of the pressing machine itself, the mold moves abruptly and a large force is locally or instantaneously applied to the work, and the work is damaged or distorted. . In particular, when the work is glass, the temperature of the glass is lower and the glass is hardened at the end of pressing than at the start of pressing, so when the glass is separated from the mold at the end of pressing, The mold may give an impact to the glass and damage it due to the influence of bending or play.

[0012]

The present invention has been made to solve the above-mentioned problems, and in a press machine for molding glass by sandwiching the glass with a plurality of molds and applying pressure, An armature that has a ferromagnetic part, a mechanism that fixes the die and the armature, a mechanism that movably holds the die and the armature that are fixed to each other in a floating state, and apply a suction force to the ferromagnetic body of the armature It is composed of a plurality of electromagnets for controlling the position / orientation of the mold with multiple degrees of freedom, a control device for controlling the current value flowing in the electromagnet, and a sensor for detecting the position / orientation of the mold. A multi-degree-of-freedom alignment device for a die is provided.

According to the present invention, in a pressing step of molding glass by sandwiching the glass with a plurality of molds and applying a pressure, at least a fixed to an armature before applying a pressure between the plurality of molds. By holding one mold movably and controlling the attractive force of multiple electromagnets placed facing the ferromagnetic part of the armature, the position and posture of the mold fixed to the armature with multiple degrees of freedom. The present invention provides a positioning method characterized in that the positions of a plurality of molds are adjusted by manipulating.

As a mechanism for movably holding the fixed mold and the armature of the present invention in a floating state,
A magnetic levitation mechanism, an air levitation mechanism, a levitation mechanism such as a hydraulic levitation mechanism, and a ball bearing support are preferable because they can be movably supported with low friction, but among them, static pressure air levitation enables stable levitation. The device can be made smaller and lighter,
It is preferably used because it is easy to maintain and can support a large and heavy glass mold.

As a sensor for detecting the position / orientation of the mold of the present invention, a plurality of non-contact type sensors such as an eddy current type gap sensor, an electrostatic capacitance type gap sensor, and a laser position sensor are used. This is preferable because it does not interfere with alignment and has high measurement accuracy.

The present invention further relates to a ferromagnetic material member fixed to a mold and a ferromagnetic member fixed to the mold in a press machine for sandwiching the work with a plurality of molds and applying pressure to mold the work. A stored electromagnet, a sensor that detects the relative position of the mold and the electromagnet, and a control device that controls the current flowing through the electromagnet so that the pressure applied to the work sandwiched by the multiple molds gradually changes. There is provided a bias weight correction device comprising:

Further, according to the present invention, in a pressing step in which a work is sandwiched between a plurality of molds and pressure is applied to form the work, the current of an electromagnet opposed to a ferromagnetic member fixed to the molds. A biased weight correction method characterized in that the suction force between the mold and the electromagnet is changed by controlling the value to gradually change the pressure applied to the work sandwiched by the plurality of molds. I will provide a.

The pressing means referred to in the present invention means, for example, in FIG. 1, a lifting / pressurizing mechanism 15, a frame 20, electromagnets 21, 2
6, an entire lifting drive unit that is connected to the armature 25 such as the air nozzles 22 and 23 and that moves the mold 13 up and down to press-mold glass.

As the ferromagnetic material of the present invention, soft iron, steel, silicon steel, stainless steel, etc. are preferably used. As the elastic body, rubber, spring or the like is preferably used.

As a controller for controlling the value of the current flowing through the electromagnet in the present invention, a known power supply device capable of varying the current value is fed back with information on the position and orientation from the sensor to obtain the current value. A variable control circuit, a controller, a device to which a microcomputer or the like is connected, or the like can be used.

In the present invention, the mechanism for movably holding the armature in a floating state means that the armature 25 is floated in the frame 20 by compressed air or the like in FIG. It is a mechanism that makes it movable.

[0022]

The positioning device and the positioning method of the present invention function in the following procedure. The armature and the mold fixed to each other are movably supported in a floating state, and the displacement of the supplied mold and the other mold of the glass gob to be pressed is directly measured, or the same mold is used before. It is estimated by measuring the dimensions of the glass product, and the position / orientation of the mold fixed to the armature is controlled by the attraction force of the electromagnets arranged around the armature. To match. The above operation must be completed from the end of the previous press to the time immediately before this press. During the press
The position and orientation of the upper die can be held by magnetic force, or can be mechanically fixed to the press machine.

The multi-degree of freedom of the mold can be positioned at high speed and with high accuracy by the principle of moving the mold in a floating state by using the attraction force of the controlled electromagnet. The positioning accuracy is in the same order as the accuracy of the sensor that measures the position / orientation of the mold in the absence of friction. When the multi-degree-of-freedom positioning is performed by the present invention, the positioning time is shorter and the accuracy is better than that of the conventional method, so that the accuracy of the die positioning during pressing can be improved. Therefore, there is an effect that the fitting gap between the molds can be reduced. Further, since it is possible to cope with a thermal positional deviation at the time of starting the glass molding job, an effect of shortening the starting time can be obtained. Furthermore, since it can be easily additionally attached to the existing press machine, it is possible to omit the step of remodeling the existing equipment in the factory in order to achieve high accuracy.

The bias weight correction device and bias weight correction method of the present invention estimate the force that causes backlash, flexure or partial contact when the press machine experiences non-negligible backlash or flexible partial contact. A current is passed through the electromagnet so as to cancel the force. At this time, the attractive force generated by the electromagnet is
Since it is determined from the current value flowing in the electromagnet and the positional relationship between the electromagnet and the ferromagnetic material facing the electromagnet, conversely, from the output of the sensor that detects the relative position of the mold and the electromagnet and the magnitude of the attractive force to be generated. The control device that controls the current flowing through the electromagnet can calculate the value of the current flowing through the electromagnet.

Furthermore, a portion where backlash and flexure are intentionally generated is attached to the press machine, and within the range of the backlash and flexure,
The pressure applied to the work from the mold can be controlled by the attractive force of the electromagnet, and it is possible to realize not only the correction of the biased load but also the pressure distribution that cannot be generated by the conventional press machine.

Since the current passed through the electromagnet can be changed at high speed, it is possible to control with a fine force during a short pressing time, and it is possible to perform highly accurate pressing. In particular, at the time of contacting and separating the mold and the work at the start and end of the press, high-speed force control, which was impossible with the conventional technology, is possible, and it is possible to prevent unacceptable distortion and scratches on the work. It has the effect of being avoidable.

[0027]

Embodiments of the present invention will now be described in detail with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a positioning device according to the present invention, FIG. 2 is a cross-sectional view of the positioning device, and FIG. 3 is a flowchart of a positioning method.

This embodiment is an example of a positioning device and a positioning method when the upper die is a movable body.

In the figure, 13 is a mold upper mold, 12 is a mold lower mold,
25 is an armature integrated with the upper mold, 21
Are eight electromagnets that move the armature 25 back and forth and left and right and rotate about a vertical axis, and 26 is the armature and the frame 2.
Four electromagnets for fixing 0, 24 is three or more gap sensors for measuring the relative positions of the upper die and the lower die, 20 is a frame to which the electromagnet 21 is fixed, 22 and 23 are armatures 25 and upper die An air nozzle for floating 13 in the air, 1
Reference numeral 5 is a lifting / pressurizing mechanism for the frame 20, and 11 is a glass gob.

Hereinafter, a press work procedure including alignment will be described with reference to FIG. First, as shown in FIG. 2, the upper die 13
The glass gob 11 is supplied to the mold lower die 12 in a state where the mold lower mold 12 and the mold lower mold 12 are separated from each other. The mold upper die 13 is attached to the nozzles 22, 23
By ejecting air from the air, the air is levitated and brought into a floating state. Next, the lifting / pressurizing mechanism 15 lowers the upper die 13 of the mold. The currents of the eight electromagnets 21 are controlled from the time when the upper die 51 moves down to the point where the sensor 24 can measure the position of the lower die, and the upper die 13 is controlled.
And the lower die 12 are aligned. After the alignment is completed, the air supply to the nozzle 23 is stopped and a current is passed through the electromagnet 26 to fix the upper die 13 to the frame 20 in contact therewith. Furthermore, the lifting / pressurizing mechanism 15 lowers the upper mold 13 to pressurize the glass gob 11. After the pressing is completed, the lifting / pressurizing mechanism 15 pulls up the upper die 13 to set the current value of the electromagnet 26 to zero.

When the panel of the cathode ray tube was press-molded by the above-mentioned apparatus and method, 0.1m was obtained when the panel thickness variation of the panel was 0.2 mm or more.
m or less, and the production yield was improved.

(Embodiment 2) The same apparatus as in Embodiment 1 is used to correct the dimensional error of past pressed products, that is, the size derived from the last several products (2 to 5). When the alignment was performed using the average value of the errors,
The panel thickness error was reduced to 0.1 mm or less, and the manufacturing yield was further improved. Also, the fitting gap 18 has been successfully reduced.

(Third Embodiment) The sensor 24 is not provided,
The same apparatus as in Example 1 except that six sensors for measuring the position of the die upper die 13 are provided beside the electromagnet 21, and a target value for alignment is calculated and designed only from the dimensional error of past press products. If you do, the thickness error of the panel is 0.1mm
It was about.

The present invention is not limited to the above embodiment. For example, the armature 25 need not be levitated by air, but may be ball bearing support, hydraulic support, or magnetic levitation. The movable part by magnetic force does not need to be the upper mold, and the lower mold may be the movable part, or both the upper mold and the lower mold may be movable. For light presses that do not require high press pressure, the upper die 1
It is also possible to carry out the pressing work while the 3 is being levitated while being held only by the magnetic force of the electromagnet. The number and arrangement of the sensors need not be the same as the above example as long as the relative displacement between the upper die and the lower die can be detected. Further, the arrangement and number of electromagnets and the shape of the armature are not limited to the above examples, and various modifications exist.

Further, it goes without saying that various modifications can be made without departing from the scope of the present invention.

FIG. 4 is a block diagram of a press device including the bias weight correction device according to the present invention, and FIG. 5 is a flow chart showing the bias weight correction method. The present embodiment is an example of a bias weight correction device and bias weight correction method for applying a suction force of an electromagnet to a mold upper die to correct a biased weight that tilts the mold upper die.

In the figure, 151 is a mold upper mold whose biased weight is corrected, 152 is a mold lower mold, and 122 is eight electromagnets for correcting a force that causes the mold upper mold 151 to tilt. 15
0 is an auxiliary tool made of a ferromagnetic material (steel) for transmitting the magnetic attraction force of the electromagnet 122 to the mold upper die 151, and 121 is for measuring the relative positional relationship between the mold upper die 151 and the electromagnet 122. A plurality of gap sensors, 120 is an electromagnet 12
2 fixed frame, 123 is upper mold 151 and frame 120
The play (play), 156, is intentionally made between the frame 12
A lifting / pressurizing mechanism of 0, 154 is a work (molten glass: gob) to be pressed.

The press work procedure including the bias weight correction will be described below with reference to FIG. First, as shown in FIG. 4, with the upper mold 151 and the lower mold 152 separated, the work 154
Is supplied to the mold lower mold 152. Next, the lifting / pressurizing device 15
6, the upper die 151 is lowered. Mold upper mold 15
When the 1 starts to contact the work 154, the upper mold 151
By controlling the current value of the electromagnet 122 in consideration of the output of the gap sensor 121 in the play range between the frame 120 and the frame 120, it is possible to prevent uneven contact of the upper mold 152. Further, when the upper die 151 is lifted by the lifting / pressurizing mechanism 156 after the press is finished, the upper die 151 is smoothly separated from the work 154, and when the upper die 151 is separated, the imbalance of the upper die 151 causes the die to move. The imbalance of the die upper die 151 is controlled by using the information of the sensor 121 with respect to the current value of the electromagnet 131 so that the upper die 151 does not collide with the work 154 by hitting it again.
By doing so, it is possible to prevent the work 154 from being scratched when the upper mold 151 after pressing is pulled up. In particular, when it is applied to a press for a cathode ray tube funnel, it is possible to suppress scratches that occur during pressing.

The present invention is not limited to the above embodiment. For example, when a biased load is generated on the mold lower die 152, or when a biased load that moves the mold in a horizontal direction is corrected, the number of electromagnets and a partner that exerts an attractive force are operated based on the same principle as in the above embodiment. The same effect can be obtained by changing the location, the location, and the direction. It is not always necessary to intentionally make play between the mold and the frame, and it is possible to use the play and deflection of the press itself. For light presses that do not require high press pressure, the upper die 1
While magnetically levitating 51 with the attraction force of the electromagnet 132, the attraction force of the electromagnet 132 can be controlled to adjust the press pressure while performing the pressing. The arrangement of the sensors does not have to be as in the above example as long as the positional relationship between the electromagnet and the ferromagnetic material facing the electromagnet can be detected. Further, the arrangement and number of electromagnets and the shape of the ferromagnetic body that receives the attractive force are not limited to the above examples, and various modifications exist.

Further, it goes without saying that various modifications can be made without departing from the scope of the present invention.

[0041]

INDUSTRIAL APPLICABILITY The present invention has the excellent effect of improving the dimensional accuracy and the manufacturing yield as compared with the conventional glass press machine, and also has a scratch on the pressed product as compared with the conventional press machine. It has an excellent effect that the strain and the strain can be reduced and the manufacturing yield can be further improved.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing the manufacture of a press machine including the alignment device of the present invention.

FIG. 2 is a cross-sectional view of the alignment device of the present invention.

FIG. 3 is a flowchart showing a positioning method of the present invention.

FIG. 4 is a vertical cross-sectional view showing the structure of a press machine including the bias weight correction device of the present invention.

FIG. 5 is a flowchart showing a bias weighted correction method of the present invention.

FIG. 6 is a plan view showing a layout of a glass pressing process according to a conventional technique.

FIG. 7 is a vertical sectional view of a glass press machine according to the related art.

FIG. 8 is a vertical sectional view of a pressing machine according to the related art.

[Explanation of symbols]

 11 ... Glass gob 12 ... Mold lower mold 13 ... Mold upper mold 14 ... Mold upper mold 15 ... Lifting / pressurizing mechanism 16 ... Key 17 ... Key groove 18 ... Fitting gap 20 ... Frame 21 ... Electromagnet 22 ... Air nozzle 23 ... Air nozzle 24 ... Gap sensor 25 ... Armature 26 ... Electromagnet 30 ... Rotating table 31 ... Loading position 32 ... Press position 120 ... Frame with fixed electromagnet 121 ... Gap sensor 122 ... Electromagnet 123 ... Rattling 150 ... Made of ferromagnetic material Auxiliary tool 151 ... Mold upper mold 152 ... Mold lower mold 154 ... Workpiece 155 ... Mold upper mold guide 156 ... Lifting / pressurizing mechanism

Front Page Continuation (72) Inventor Hideharu Odajima 1150 Hazawa-machi, Kanagawa-ku, Yokohama, Kanagawa Asahi Glass Co., Ltd. Central Research Laboratory (72) Inventor Manabu Nito 1-10-1 Kitahonmachi, Funabashi-shi, Chiba Asahi Glass In Funabashi Plant Co., Ltd. (72) Inventor Kazuyuki Ueda 1-10-1 Kitahonmachi, Funabashi City, Chiba Asahi Glass Co., Ltd. Funabashi Plant

Claims (13)

[Claims] 1. A press molding apparatus in which a pressing means for pressing a material to be molded between the two dies is connected to one of the upper die and the lower die, wherein the one die is used. The pressing means and the one of the molds are connected to each other via a position and posture adjusting means of the molds for aligning the molds capable of controlling the connecting and fixing force of the pressing means with respect to each other or for correcting the biased load. Press molding equipment characterized by. 2. The position and attitude adjusting means of the mold comprises:
A ferromagnetic member fixed to one side of the one die or the pressing means, an electromagnet provided on the other side facing the ferromagnetic member, and a sensor for detecting the position of the die. The press molding apparatus according to claim 1, further comprising: a control unit configured to control an attraction force of the electromagnet according to a detection output of the sensor. 3. A press machine for molding glass by sandwiching the glass with a plurality of molds and applying pressure thereto,
An armature having a ferromagnetic material portion, a mechanism for fixing the die and the armature, a mechanism for movably holding the die and the armature fixed to each other in a floating state,
A plurality of electromagnets for controlling the position and orientation of the mold with multiple degrees of freedom by exerting attractive force on the ferromagnetic material of the armature, a control device for controlling the current value flowing through the electromagnet, and the position of the mold A multi-degree-of-freedom alignment device for a die of a press molding device, which is configured by a sensor that detects a posture. 4. A mechanism for movably holding a mold and an armature fixed to each other in a floating state,
The positioning device according to claim 3, wherein a levitation mechanism such as a magnetic levitation mechanism, an air levitation mechanism, or a hydraulic levitation mechanism is used. 5. The pressed product is a cathode ray tube panel or funnel.
Or the alignment device according to 4. 6. At least one metal fixed to an armature before a pressure is applied between a plurality of molds in a press step of molding glass by sandwiching the glass with a plurality of molds and applying a pressure. By holding the mold in a floating state and controlling the attractive force of multiple electromagnets placed facing the ferromagnetic part of the armature, the position of the mold fixed in the armature with multiple degrees of freedom
A positioning method for a press molding apparatus, characterized in that a plurality of molds are adjusted in position by manipulating a posture. 7. The positioning method according to claim 6, wherein a mechanism for movably holding the mold and the armature is stopped at the time of pressing, and the mold and the armature are fixed to the press machine. 8. A press machine for forming a work by sandwiching the work with a plurality of molds and applying pressure to the work, the member being made of a ferromagnetic material fixed to the dies, and facing the ferromagnetic material. An electromagnet, a sensor that detects the relative position of the mold and the electromagnet, and a control device that controls the current flowing through the electromagnet so that the pressure applied to the work sandwiched by the multiple molds gradually changes. Unbalanced weight compensation device for press molding equipment. 9. The bias weight correction device according to claim 8, wherein an elastic body is provided between the die and the press machine or a play is provided. 10. The bias weight correction apparatus according to claim 8 or 9, wherein the pressed product is a cathode ray tube panel or a funnel. 11. A current value of an electromagnet that is opposed to a ferromagnetic member fixed to a mold in a press process in which a work is sandwiched between a plurality of molds and pressure is applied to mold the work. Then, the suction force between the mold and the electromagnet is changed so that the pressure applied to the work sandwiched by the plurality of molds is gradually changed. Method. 12. The pressure applied to the work is gradually changed without suddenly changing the pressure applied from the mold to the work in the process of separating the work from the mold at the end of pressing. 12. The bias weighted correction method according to claim 11, further comprising controlling a current value flowing through the electromagnet. 13. The pressure applied to the work is gradually changed without suddenly changing the pressure applied from the mold to the work in the process of contact between the mold and the work at the start of pressing. 12. The bias weighted correction method according to claim 11, further comprising controlling a current value flowing through the electromagnet.