JP3297616B2 - Moving die plate stop position control method and apparatus for foam molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a stop position of a movable die plate to which a movable mold of a foam molding machine is attached.
Those concerning the legal and apparatus.

[0002]

2. Description of the Related Art FIGS. 1 to 4 show the essential parts of a foam molding machine suitable for carrying out the method of the present invention. The basic structure is the same as that of a conventional foam molding machine. The operation of a general foam molding machine will be described with reference to these drawings.

[0003] (3) is a fixed die attached to the fixed die plate (4). (2) is a moving die attached to the moving die plate (1). The movable die plate (1) moves along a tie bar or the like to open and close the mold.

FIG. 1 is a view showing a state in which foamed resin beads prefoamed from a filler (10) are fed into a cavity between the molds (2) and (3). At this time, the molds are not completely closed, but are located with a slight gap (C) between the molds (2) and (3).

[0005] This is because when filling the foamed resin beads, the air in the cavity is released to the outside so that the beads can be easily and reliably filled. Positioning the movable mold (2) such that a slight gap (C) is formed between the molds in this way is called "cracking".

[0006] The gap (C) between the dies during the cracking is
If it is too narrow, the air inside the cavity can be efficiently removed
If it is not possible, if it is too wide, foam resin beads in the cavity
Spills out of the cavity. Therefore, the gap
The width of (C) is determined in consideration of the size of foamed resin beads, etc.
Have been.

After the filling of the foamed resin beads is completed, the mold is completely closed as shown in FIG. 2, and high-temperature steam is blown into the mold from the steam pipes (5) and (6) to foam the foamed resin beads in the cavity. The steam is discharged from the exhaust pipes (7) and (8).

Thereafter, as shown in FIG. 3, the movable die plate (1) is moved to open the mold, and as shown in FIG. 4, the extruding portion (9) is operated to form the mold in the fixed mold (3). Goods
(A) is taken out of the mold (3).

The width of the gap (C) at the time of cracking has an important meaning as described above, and the following means has conventionally been used for the control thereof. The movable die plate (1) is operated by hydraulic pressure, but starts moving to the fixed die plate (4) side at a high speed from the mold open state. When it approaches the fixed die plate (4) side to some extent, it switches to low speed movement by adjusting the oil pressure.

Further, when the movable die plate (1) approaches the fixed die plate (4) side and depresses a limit switch set at a predetermined position, a stop command is transmitted, the hydraulic pressure is cut off, and the movable die plate (1) is released. Stop. Since the movable die plate (1) is operated by hydraulic pressure, it cannot be stopped instantaneously even if the hydraulic pressure is cut off by the stop command, and slightly moves after the stop command is transmitted.

Therefore, the position of the limit switch is provided at a position farther from the fixed die plate (4) than the actual desired stop position in consideration of the movement after the stop command.

If the moving distance from the receiving of the stop command of the movable die plate (1) to the actual stop is always constant, it is only necessary to provide the limit switch at a fixed position. The stop position is not constant due to a change in temperature (rise), a change in the tie bar interval due to the temperature change, a change in the resistance of the bush, and the like.

As described above, if the size of the interval (C) between the molds (2) and (3) is too large or too small, it is inconvenient.
Frequently, the position of the limit switch had to be fine-tuned to keep the stop position as constant as possible.
Further, since the adjustment amount is about 0.1 mm, a skilled technique for tightening a screw for fixing the limit switch and the like is required.

[0014]

It is therefore an object of the present invention to automatically adjust the stop position of the moving die plate of the foam molding machine to reduce errors in the stop position.

[0015]

A moving die plate stop position control method for a foam molding machine according to the present invention comprises the steps of: moving a hydraulically driven moving die plate (1) at a high speed; In the stop position control method of stopping the moving die plate (1) near the set stop position (C) by switching to the low speed movement before, the moving die plate (1) starts from the position (Y _m ) where the die plate stop signal was issued. ) Measures the distance to the position where it actually stopped (X _m ) and outputs the die plate stop signal.
Calculates the average value (b _m ) of the distance from the issued position (Y _m ) to the actual moving die plate (1) stop position (X _m ), and outputs the die plate stop signal (Y _{m + 1} ) Is changed from the set stop position (C) by the average value (b _m ) to the position on the mold opening side so that the set stop position (C) of the movable die plate (1) and the actual stop position (X _m The apparatus for performing the above method includes a fixed die plate (4) on which a fixed mold (3) is attached, and a movable mold (2) attached. Moving die plate (1) and moving die plate
(1) is out with potentiometer for detecting (11) constituting the moving amount of the distance position that issued the die plate stop signal from the (Y _m) to actually stop position the movable platen (1) (X _m)
(b) is measured with a potentiometer (11), the average value (b _m ) of the distance is calculated, and the position (Y
_{m + 1} ) is changed from the set stop position (C) by the average value (b _m ) to the position on the mold opening side, so that the set stop position (C) of the movable die plate (1) and the actual It is characterized in that an error from the stop position (X _m ) is reduced.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to preferred embodiments. As shown in FIGS. 1 to 4, a gear meshing member (13) is attached to the movable die plate (1).
This gear meshing member (13) meshes with the gear (12),
The rotation of (12) is transmitted to the potentiometer (11). That is, the position of the movable die plate (1) can be detected by the potentiometer (11).

First, the average value of the distance (overrun amount) from when a maker issues a stop command to when it actually stops is measured, and based on the measured value, the set stop position and the actual stop position are matched. Set the stop command position.

When the user or the like actually operates, a deviation between the set stop position and the actual stop position occurs. In this embodiment, the deviation is corrected as follows. That is, the distance from when a stop command is issued until the actual stop is detected, an average value is calculated from a plurality of detection results, and the stop command position is shifted from the set stop position by the obtained average value (correction value). It has been changed to be located on the open side. The detection of these distances and the calculation and the change of the stop command position are automatically performed.

The average of a plurality of overruns is calculated. If the stop command position is moved based on only the amount of overrun associated with one operation, the response becomes too sensitive and handling is difficult. Because it becomes.

In the present embodiment, the numerical value for calculating the position is such that the mold clamping completion position is 0 and the numerical value increases toward the mold opening completion position (rightward in the figure). Therefore, the following relationship is obtained: Ym + 1 = C + bm Ym + 1 : The value of the moving die plate stop command position after correction C: The value of the set stop position (desired stop position) bm: Correction value (average value of overrun amount) Can be

Since the actual stop position Xm at the m-th time is always closer to the mold clamping completion position than the stop command position Ym at that time, the value is always smaller than Ym, and bm is always a positive value.
Here, bm is, for example, bm = [( _{Ym- (n-1)} -Xm- _(n-1) ) + ( _{Ym- (n-2)} -X
_{m− (n−2)} ) +... + (Y _m −X _m )] / n. That is, bm is an average value of the measured values of the overrun amount of the latest n times.
Move by m so that the stop command position is on the mold opening side.
(Of course, if bm is the same as the average value calculated last time, the stop command position does not move.) Thereby, the value of the actual stop position Xm approaches the value of the set stop position C.

If an average value is calculated by sampling five measured values, the measured values to be averaged are, for example, the first to fifth times, the second to sixth times, and then the third to seventh times. The measurements to be averaged may partially overlap.

Further, continuous measurement values within a non-overlapping range, such as the first to fifth times, followed by the sixth to tenth times, may be used.
A measurement value with an interval such as the 25th to 25th measurement may be used.

The stop command position may be changed every time the correction value is calculated, or the error between the actual stop position and the set stop position may be within a predetermined error tolerance (one time or continuously).
You may go when you exceed.

FIG. 5 is a diagram showing the variation of the actual stop position of the movable die plate (1). The solid line indicates the case where the stop instruction position is not corrected, and the broken line indicates the stop instruction position according to the present invention. 3 shows a case where the correction has been performed.

As is apparent from FIG. 1, when no correction is performed, a deviation of 1 mm or more occurs at the maximum, and the error is too large. On the other hand, when the correction is performed, the error is ± 0.25 mm or less, and the movable die plate (1) has a sufficiently practical value.
Could be stopped.

In the above embodiment, the movable die plate (1)
Is detected by the potentiometer (11) and the gear (12), but may be detected by another means.

[0028]

As described above, according to the present invention, the stop position of the movable die plate can be automatically adjusted, so that the movable die plate can always be stopped at an appropriate position without any skill. .

[Brief description of the drawings]

FIG. 1 is a diagram showing a state in which foam beads are injected into a cavity between molds of a foam molding machine.

FIG. 2 is a diagram showing a state in which a mold is closed and foam beads are foamed.

FIG. 3 is a view showing an opened state.

FIG. 4 is a view showing removal of a molded product.

FIG. 5 is a diagram showing a change in an actual stop position.

[Explanation of symbols]

 (A) Foam molded product (C) Gap between dies (1) Moving die plate (2) Moving die (3) Fixed die (4) Fixed die plate (5) Steam piping (6) Steam piping (7 ) Exhaust pipe (8) Exhaust pipe (9) Extruded part of molded product (10) Filler (11) Potentiometer (12) Gear (13) Gear meshing member

Continuation of the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B29C 44/00-44/60 B29C 67/20 B29C 33/00-33/24

Claims (2)

(57) [Claims] [Claim 1] After the movable die plate of the hydraulic drive moved at high speed, class switch to slow moving before setting the stop position
In the stop position control method for stopping the movable die plate near the set stop position for locking , the distance from the position where the die plate stop signal is issued to the position where the movable die plate is actually stopped is measured, and the distance is measured. By calculating the average value and changing the position at which the die plate stop signal is output from the set stop position by the average value to the position on the mold opening side, the error between the set stop position of the moving die plate and the actual stop position A method for controlling a stop position of a moving die plate of a foam molding machine, characterized in that the number of movements is reduced. 2. A fixed die having a fixed mold attached thereto.
Plate and moving die plate with moving mold
And a potentiometer that detects the amount of movement of the moving die plate
Stops the moving die plate of the foam molding machine composed of
In the position control device, Moving die play from the position where the die plate stop signal was issued
The distance to the position where the
, Calculate the average value of the distance, The position where the die plate stop signal is output is
By changing only the average value to the mold open side position
The set stop position of the moving die plate and the actual stop position
Movement of a foam molding machine characterized by reducing errors in
Die plate stop position control device.