JPH07491B2 - Automatic centering device for plunger mechanism in glass bottle molding machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to an automatic centering device for a plunger mechanism in an IS type glass bottle molding machine.

(Prior Art) The IS-type (independent section type) glass bottle molding machine is a typical glass bottle molding machine in which a large number of molding sections of the same structure that are operated with a predetermined phase difference are connected in series. In this case, the gob thrown into the rough mold of each section is molded into a parison by a plunger mechanism, and the parison is blow-molded with a finishing mold to mold a glass bottle. In such a glass bottle molding machine, it is necessary that the center of the rough mold of each section and the center of the plunger mechanism are accurately aligned, and if the cores of both parts are misaligned, parison molding will be performed smoothly. It is empirically known that various molding defects will occur because the mold will not be lost.

However, since the glass bottle molding machine molds high-temperature glass, the dimensions of each mechanism change due to thermal expansion between the hot state during glass molding and the cold state when the molding is stopped, and the center of the plunger mechanism is roughened in the cold state. Even if it is correctly aligned with the center of, the center will be slightly out of order in the hot state. Therefore, the thermal expansion is predicted so that the center comes out correctly in the hot state, and the center is intentionally shifted in the cold state to set the plunger mechanism. However, in spite of such ingenuity, the misalignment may become apparent only after observing the molding state of the glass bottle after the start of molding. In such a case, the molding machine must be stopped once to perform the centering work, and a loss of several tens of minutes cannot be avoided.

(Problems to be Solved by the Invention) The present invention solves the above-mentioned conventional problems, and automatically detects the misalignment of the plunger mechanism of the IS type glass bottle molding machine, and automatically performs the alignment. The present invention is made to provide an automatic centering device for a plunger mechanism in a glass bottle molding machine capable of performing the above.

(Means for Solving the Problems) The present invention, which has been made to solve the above problems, is provided on a table that can move the plunger mechanism of each section of an IS type glass bottle molding machine in both X and Y axis directions by a motor. Each plunger mechanism is equipped with an operation sensor that detects the displacement of the conductor mounted on its movable side at a fixed pitch, and when the operation sensor detects an abnormal waveform, it sends an operation signal to the motor. It is characterized in that a control device for sending the

Hereinafter, the present invention will be described in more detail with reference to the illustrated embodiments.

(Embodiment) FIG. 1 is a perspective view schematically showing the whole embodiment of the present invention, and shows two plunger mechanisms (1), (1) for a double cavity of a molding section. There is. Although only two units are shown in the figure, the plunger mechanism (1) having the same structure for each section,
It goes without saying that (1) is installed.

Each plunger mechanism (1), (1) is installed on a table (2), (2), respectively, and these tables (2), (2) place X, Y on the upper surface of the saddle plate (3). It has a structure that can slide in both axial directions. Therefore, each table (2) has a feed screw (1
1) and the Y-axis feed screw (12) are screwed together,
Replace these lead screws (11) and (12) with the worm gear (1
Stepping motors (14), (1) via (3), (13)
It is possible to move the tables (2) and (2) to arbitrary positions by rotating them by an angle controlled by 4). Note that (15) and (16) are sensors that detect the movement amounts of the tables (2) and (2) in the X-axis direction and the Y-axis direction.

On the other hand, in the present invention, the plunger mechanism (1) is provided with an operation sensor for detecting its operation. FIG. 2 is a view showing a specific structure of the operation sensor, (5) is a piston rod of a plunger mechanism, and (6) is a cylinder. A ring-shaped conductor (7) is attached to the surface of the piston rod (5) at a constant pitch, and a coil (8) is attached to the cylinder (6). The structure and operating principle of this operation sensor are as follows.

That is, as shown in FIG. 3, the coil (8) includes primary coils (9a) to (9d) and secondary coils (10a) to (10d), and the cylindrical space of these coils is a piston rod ( It is designed to be concentric with 5). The conductor (7) is made of a conductor that is better than the material of the piston rod (5), and aluminum, copper, etc. can be used,
The surface may be coated with other materials.

When the coil (8) is excited by the primary AC signal, A,
It operates in four phases, B, C, and D, and the magnetic resistance shifts by 90 ° depending on the relative position of the conductor (7) with respect to the coil. For example, when the A phase is a cosine phase, the B phase is a sine phase, the C phase is a minus cosine phase, and the D phase is a minus sine phase.

In the embodiment, the primary coils (9a) to (9d) of each phase and the secondary coils (10a) to (10d) are wound at the same position, and the length of each coil is P / 2 (P is an arbitrary value). Number). A-phase and C-phase coils and B-phase and D-phase coils are provided adjacent to each other, and the spacing between the coil groups is [P × (n + 0.25)].
(N is an arbitrary natural number).

In the above configuration, the primary coils of each phase (9a) to (9d)
When the conductor (7) enters the magnetic field through the piston rod (5), an eddy current flows along the ring-shaped conductor (7) according to the amount of penetration. As a result,
An eddy current flows through each conductor (7) according to the degree of penetration of the conductor (7) into the primary coil of each phase, and a magnetic resistance change due to this eddy current loss occurs in the magnetic circuit of each phase. Then, an AC signal having a level corresponding to the magnetic resistance is excited in the secondary coils (10a) to (10d) of each phase.

In the embodiment, the piston rod (5) is formed by the phase shift method.
The output signal according to the linear position of is obtained.
That is, in each phase, a periodic magnetic resistance change occurs according to the linear displacement of the piston rod (5), and the phase of this magnetic resistance change is deviated by 90 degrees (P / 4) between adjacent phases.
Therefore, if the phase angle corresponding to the linear displacement is represented by φ, the level of the voltage excited in the secondary coils (10a) to (10d) of each phase will be at the linear position (that is, φ) of the piston rod (5). Accordingly, it can be expressed by the formulas of cos φ for A phase, sin φ for B phase, −cos φ for C phase, and −sin φ for D phase (however, 2π corresponds to P). The A-phase and C-phase primary coils (9a) and (9c) are excited by the sine wave signal sin ωt,
The B-phase and D-phase primary coils (9b) and (9d) are cosine wave signals co
Excited by s ωt. And the secondary coil (10a),
The output signals of (10c) are added differentially, and the secondary coil (10c
The output signals b) and (10d) are also added differentially, and the differential output signals of the respective phases are added and combined to obtain the final output signal Y. Then, the final output signal Y can be expressed by the following equation.

Y = sin ωt cos φ-(-sin ωt cos φ) + cos ωt sin φ-(-cosωt sin φ) = 2sin ωt cos φ + 2cos ωt sin φ = 2sin (ωt + φ) where φ corresponds to the linear position of the piston rod (5) Therefore, the position of the piston rod (5) can be accurately detected by measuring the phase shift φ of the output signal Y corresponding to the primary AC signals sin ωt and cos ωt by a known phase difference detection circuit.

The phase shift data Dφ obtained as described above indicates the absolute position of the piston rod (5) within the range of the length P of one cycle of the periodic pattern of the conductor (7). The current position of the piston rod (5) with respect to the predetermined origin position is data indicating in the phase shift data Dφ what cycle the conductor (7) currently entering the coil (8) is from the origin position. It can be specified by combination with Dx. The signal processing method is not necessarily limited to the phase shift method. By the above method, the absolute position of the molding member operating device such as the piston rod (5) of all sections of the IS-type glass bottle molding machine can be accurately measured in the order of 1 μm.

FIG. 4 is a graph showing an operation curve of the piston rod (5) electrically taken out during the glass forming as described above, in which the vertical axis represents the output voltage and the horizontal axis represents the time. The reference waveform is shown by the solid line in FIG. 4, and the first flat portion shows the state in which the plunger has risen to the loading position, and then rises to the highest position for pressing.

When the plunger is correctly aligned, the plunger (piston rod) rises smoothly according to the reference waveform, but in the case of poor alignment, as shown by the broken line in the example, stagnation or speed A decrease etc. will occur. Then, the operation curve of the actually measured piston rod (5) indicated by a broken line is compared with a reference waveform representing normal operation, and when there is a displacement or a time lag between the reference waveform and the reference waveform, the control device causes the stepping motor to move. Send an operation signal to (14), (14),
Move table (2) in small increments. It should be noted that it is possible to estimate with a considerable probability whether the deviation of the core is in the X-axis or the Y-axis from the deviation state of the operation curve of the piston rod (5). 2)
It is also possible to adopt a trial-and-error method in which the table (2) is moved in the Y-axis direction by detecting whether or not the deviation of the operating curve is corrected by moving the table. Thus, according to the present invention, the center of the plunger mechanism can be automatically adjusted while molding the glass bottle.

(Effects of the Invention) As described above, according to the automatic centering device for the plunger mechanism in the glass bottle molding machine of the present invention, the misalignment of the plunger mechanism of the glass bottle molding machine in the hot state is caused by each plan. The special operation sensor attached to the jar mechanism detects it with high accuracy, and the stepping motor is operated to move the table along with the plunger mechanism in both the X and Y axis directions. . Therefore, unlike the conventional method, it is not necessary to perform centering that predicts thermal expansion in the cold state, and it is not necessary to stop the glass bottle molding machine during the molding to perform centering work, thus significantly reducing loss time. You can

Therefore, the present invention has an extremely great contribution to the industry as an automatic centering device for a plunger mechanism in a glass bottle molding machine that solves the conventional problems.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an embodiment of the present invention, FIG. 2 is a sectional view showing a concrete structure of an operation sensor, and FIG. 3 is an enlarged sectional view showing a structure and an operating principle of the operation sensor. FIG. 4 is a graph showing an operation curve of a piston rod that is electrically taken out during glass forming. (1): Plunger mechanism, (2): Table,
(5): Piston rod, (6): Cylinder,
(7): conductor, (8): coil, (14): motor.

Claims (1)

[Claims] 1. A plunger mechanism (1) for each section of an IS type glass bottle molding machine is installed on a table (2) that can be moved in both X and Y axis directions by a motor (14), and each plunger is also installed. The mechanism (1) is equipped with an operation sensor for detecting the displacement of the conductor (7) mounted on the movable side at a constant pitch, and further operates the motor (14) when the operation sensor detects an abnormal waveform. An automatic centering device for a plunger mechanism in a glass bottle molding machine, which is provided with a control device for sending a signal.