JPH11268070A - Foaming machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically set a steam pressure setting work performed heretofore by manual work by a skilled person to the setting condition of an attached mold. SOLUTION: A foam molding machine is constituted of a foaming mold having steam chambers 2a, 2b, the steam pipings 3a, 3b connected to the mold 1, the pressure detector detecting the pressure in the mold 1, the control valves 5a, 5b arranged to the steam pipings 3a, 3b, the drain pipings 20a, 20b connected to molds 1a, 1b and a control part (cont). The detection value of the pressure detector is compared with a preliminarily inputted set value to perform feedback control so as to match the pressure of the steam supplied to the steam chambers 2a, 2b with a set value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a foam molding machine, and more particularly to a foam molding machine employing digital feedback control.

[0002]

2. Description of the Related Art In a foam molding machine, as shown in FIG. 3, pilot pipes (23a) (23b) of pressure detecting devices (24a) (24b) are used.
Was directly connected to the male and female molds (21a) and (21b). In this way, the steam chambers (29a) (29b) of the male and female molds (21a) (21b)
This is for accurately measuring the mold pressure in the heating step. The male and female molds (21a) and (21b) have steam pipes (28a) and (28b) connected to the male and female molds (21a) and (21b) from a steam supply source (27) and other cooling pipes (not shown), Various pipes such as an air pipe (not shown) and a drain pipe (26a) (26b) are connected.
(35) are pre-expanded beads filled in a cavity formed between the male and female molds (21a) and (21b).

In foam molding, generally, one production lot is completed, and when the next lot is switched, the molds (21a) and (21b) are replaced in accordance with the next product. The piping group connected to the molds (21a) and (21b) is removed each time, and a new mold
When (21a) and (21b) are set, they are reconnected. Then, the operator directly operates the steam valves (25a) (25b) to adjust the opening of the steam pressure, the output value of the compressed air, the control pressure in each heating step, etc. each time, and performs a trial shot. The conditions for the new molds (21a) and (21b) are determined.

[0004] Such work requires not only extremely skill but also a long time even by skilled workers, and occupies a large part of the setup work. Therefore, this shortening greatly contributes to shortening of the entire working time. There has been a demand for shortening the time for this part. Further, once the setting is changed, it is difficult to reproduce the vapor pressure sometimes, it takes time and effort to determine the conditions, and there is also a problem that an error easily occurs even if the setting is reset. In addition, there is another problem that every time the molding conditions are changed, the setting must be performed again in accordance with the molding conditions, and the operation is very troublesome.

[0005]

SUMMARY OF THE INVENTION According to the present invention, the setting operation of the steam pressure, which has conventionally been performed manually by a skilled worker, is automatically set to the setting conditions of the mounted mold. The problem is to be solved.

[0006]

According to a first aspect of the present invention, there is provided a foam molding machine comprising a foam mold (1) having a steam chamber (2a) (2b).
And the steam pipes (3a) and (3b) connected to the mold (1), and the mold (1)
Pressure detectors (4a) (4b) that detect internal pressure, and steam piping
(3a) (3a) Control valves (5a) (5b)
(1a) The drain pipes (20a) (20b) connected to (1b) are compared with the detection values of the pressure detection devices (4a) (4b) and set values input in advance, and the steam chamber (2a ) (2b) a control unit (c that performs feedback control so that the steam pressure supplied to the set value is adjusted to
ont). "

[0007] According to this, due to the presence of the control unit (cont) capable of performing feedback control so that the steam pressure supplied to the steam chambers (2a) and (2b) is adjusted to the set value, the mold (1) is controlled. Accurate vapor pressure control of the foaming molding machine can be quickly reproduced according to the set conditions, eliminating the need for complicated adjustment of valves (25a) (25b) that depends on the intuition of skilled workers. Setup work can be significantly reduced.

The second aspect of the present invention is that in the foam molding machine of the first aspect, the pilot pipes (11a) and (11b) for detecting the vapor pressure connected to the pressure detecting devices (4a) and (4b) are connected to the drain valves (8a) and (8a). 8b) (8
B) It is connected upstream from (8a).]

If the connection position is upstream of the valve bodies (8a) and (8a), that is, on the mold (1) side, the drain valve (8a) or (8b) or (8a)
And if (8b) is closed, the valve body (8a) of the drain pipe (20a) (20b)
(8b) Since the portion upstream of the die (1) communicates with the inside of the steam chambers (2a) and (2b) of the die (1), the die pressure is the same. Therefore, the valve element (8a) (9b) or the valve element (8a) of the drain valve (8a) (8b) upstream of the valve element (8a) (8a) constituting the drain pipe (20a) (20b) )
(8b) If the pilot pipes (11a) and (11b) of the pressure detectors (4a) and (4b) are connected on the upstream side, the results are almost the same as those connected to the steam chambers (2a) and (2b). Can be obtained. As a result, the drain hoses (7a) (7b) and the molds (1a) (1
Since it is detached at the connection with b) (that is, at the bases (12a) and (12b)), the attachment and detachment of the pilot pipes (11a) and (11b) becomes unnecessary, and the attachment and detachment of the piping is simplified accordingly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an outline of a foam molding machine according to the present invention and a control method thereof will be described in detail with reference to the illustrated embodiments.
FIG. 1 shows an embodiment of the present invention, in which a mold (1) for foam molding is a male mold (1a).
And female type (1b), each of which is provided with a steam chamber (2a) (2b), a drain pipe (20a) (20b), and a cooling pipe (22a).
(22b) Although not shown, air piping and other necessary members are installed.

From the steam source (10), steam pipes (3a) and (3b) are led out and connected to the male and female molds (1a) and (1b), respectively. Control valves (5a) (5b) for these steam pipes (3a) (3b)
Is installed. The control valves (5a) and (5b) reduce the pressure of the steam discharged from the high-pressure steam source (10) to a required pressure and control the flow rate so that the pressure in the steam chambers (2a) and (2b) becomes a predetermined value. It is controlled so that it is maintained at the pressure, and the same effect can be achieved by adjusting the opening of the piston valve (L), so here the piston valve is used as the control valve (5a) (5b) . The steam pipes (3a) and (3b) are connected to the steam side hose (1
They are connected to the steam side bases (13a) (13b) provided on the male and female molds (1a) (1b) via 4a) and (14b).

Also, control valves for the steam pipes (3a) and (3b)
On the upstream side of (5a) and (5b), switching valves (6a) and (6b), which are two-way valves, are arranged to directly control the opening and closing of the steam pipes (3a) and (3b).

The drain side is connected to a drain base (12a) (12b) led out from the bottom of the male and female molds (1a) (1b) by a drain hose (7).
a) (7b) is detachably connected, and the drain hose (7a)
A drain valve is provided at the pipe section (9a) (9b) provided downstream of (7b).
(8a) and (8b) are connected, and the drain pipe (2
0a) and (20b).

The pilot pipes (11a) and (11b) connected to the pressure detecting devices (4a) and (4b) are provided in a pipe section between the drain hoses (7a) and (7b) and the drain valves (8a) and (8b). (9a) (9b) or valve (8
A drain valve connected to the drain valves (8a) and (8b) itself upstream of (b) and (8a) and matching the steam pressure in the steam chambers (2a) and (2b)
(18a) The pressure in (18b) is detected, and an analog signal is sent to a control unit (cont) described later instead of the analog signal. Of course, the connection positions of the pilot pipes (11a) and (11b) are not limited to the positions described above, and may be directly connected to the steam chambers (2a) and (2b) as in the conventional case.

The control unit (cont) comprises a keyboard (23), a display device (24), a control circuit (17), and control drive units (19a) (19b) such as an electropneumatic proportional valve. The control valve driving air pressure source (18) is connected to the control driving units (19a) (19b) through the control valve driving pipe (18a). The compressed air for pilot controlled by the control drive units (19a) and (19b) is supplied to the control drive units (19a) and (19a).
b) Pilot piping (11a ') (11b'), switching valve (6a) (6
b) through the control section of the control valve (5a) (5b) (5
The control valves (5a) and (5b) are supplied to the control valves (5a) and (5b) to control the valve opening degree.

The control circuit (17) includes a key input setting circuit (1) for receiving an input of a set value (X1 kg / cm ² ) from the keyboard (23).
7a), a set value storage circuit (17b) that stores the set value input to the key input setting circuit (17a) and outputs the stored content (X1) to the data conversion circuit (17c) according to the input from the keyboard (23). ),
A data conversion circuit (17c) for converting the output value (X1) from the set value storage circuit (17b) into (Y1), a pressure detection device (4a)
An analog input interface (17d) that takes in the analog signal (Z1 ′) from (4b), an A / D data conversion circuit (D1) that converts the output value (Z1 ′) from the analog input interface (17d) into (Z1). 17e), the data conversion circuit (17
c) and the output value of the A / D data conversion circuit (17e) (Y
1) to perform a comparison operation, and output a deviation (△ t) of the comparison processing circuit (17f), the output value of the comparison processing circuit (17f).
(△ t), a feedback operation circuit (17g) for performing a feedback operation, and the feedback operation circuit (17g).
g) converts the output value (ア ナ ロ グ t) from a digital value to an analog value (△ t '), a D / A data conversion circuit (17h), and a value (△ t') from the D / A data conversion circuit (17h). ) The control drive (19a)
(19b) and an analog output interface (17i).

The operation of the control unit (cont) will now be described. The foam molding process is roughly divided as described below, a “die heating process”, a “one-side heating process”, a “reverse one-side heating process” performed as needed, a “double-side heating process”, and a “cooling process”. In the present invention, “die heating step”, “one-side heating step”, “reverse one-side heating step”, and “double-sided heating step” (particularly, “one-side heating” where delicate steam pressure control is required) Process, reverse one-side heating step and two-sided heating step, or if one-sided one-side heating step is not performed, one-side heating step and two-sided heating step) The pressure control is basically performed.

In the "one-side heating step", the "one-side heating step" and the "two-sided heating step", at least one of the drain valves (8a) or (8b), or (8a) and (8b) is closed. . Then the closed drain valve (8a) or (8b),
Alternatively, steam does not flow in (8a) and (8b), so the steam chamber (2a)
Or (2b), or the same pressure as (2a) and (2b). Therefore, the pressure detection of the steam chamber (2a) or (2b), or (2a) and (2b) is performed by the closed drain valve (8a) or (8b), or (8a).
And (8b) side pressure sensing device (4a) or (4b), or alternatively (4a)
And (4b) will be used.

When the steam is supplied to the steam chamber (2a) or (2b), or (2a) and (2b) while controlling or controlling the maximum flow rate through the control valves (5a) and (5b), the steam is closed. Pressure sensor (4a) or (4b) connected to the other drain valve (8a) or (8b), or (8a) and (8b), or (4a) and (4
According to b), the steam pressure of the steam chamber (2a) or (2b) or the steam pressure of (2a) and (2b) is detected, respectively, and input to the analog input interface (17d) as an analog signal (Z1 ′).
This analog signal (Z1 ′) is converted into a digital signal (Z1) by an A / D conversion circuit (17e) and input to a comparison processing circuit (17f).

On the other hand, the data of each step of the mold (1) attached to the foam molding machine at that time is input to the set value storage circuit (17b), and the data of the step (for example, in the double-sided heating step). If so, the steam pressure (X1) Kg / cm ² ) of the mold (1) in the process is read from the set value storage circuit (17b), and the data is converted by the data conversion circuit (17c).
(X1) → (Y1) >> is output to the comparison processing circuit (17f). In the data conversion by the data conversion circuit (17c), the read value (X1) from the set value storage circuit (17b) is converted into data (Y
1), so that the output value (Z1 ′) from the analog input interface (17d) can be compared with the output value (Z1) digitally converted by the A / D conversion circuit (17e).

The comparison processing circuit (17f) compares the input two data (Y1) and (Z1), and then inputs the data to the feedback operation circuit (17g), where the deviation is determined based on (Y1). (△ t) is calculated and output to the A / D conversion circuit (17h). This digital signal (Δt) is converted into an analog signal (Δt ′) by the D / A conversion circuit (17h) and output to the analog output interface (17i).

From the analog output interface (17i), the converted analog signal (△ t ′) is output to the control valve drive unit (19a) or (19b), or (19a) and (19b),
If the set value << (X1) → (Y1) >> does not match the detected value (Z1) of the pressure detector (4a) or (4b), or (4a) and (4b), the set value << (X1) → Until the detected value (Z1) matches (Y1) >>, control of the valve opening of the control valve (5a) or (5b), or (5a) and (5b) by the control valve drive unit (19a) (19b) Is done,
The vapor pressure is controlled by the optimum set value in the process. Such an action is similarly performed in other steps as necessary. If the lot production is finished and there is a mold change,
When the mold number of the replaced mold is input, the data of the mold number is read from the storage device (17b), and the optimum feedback control is performed in each process of the mold as described above.

Hereinafter, an application example of the present invention in a heating step in a foam molding machine will be briefly described. First, prior to the foam molding work, the data of the holding mold (1) ... (for example, mold heating,
The steam pressure (X1) Kg / cm ² , (X2) Kg / cm ² … etc.) in each process such as one-side heating, reverse one-side heating, double-sided heating etc.) is input to the key input setting circuit (17a) with the keyboard (23) Then, it is stored in the storage device (17b). Of course, the optimum data may be individually input from the keyboard (23) each time the mold is replaced without using the storage device (17b).

The mold (1) is attached to the foam molding machine whose environment has been set as described above, and the data of the mold (1) is stored in a storage device.
If (17b) is stored, the mold number is input. If individual data is input, the optimum data is input from the keyboard (23) to the storage device (17b) as described above.

Next, the process proceeds to << die heating step >>
Here, the mold (1) is closed, and the closed male and female molds (1a) (1
b) Fill the cavity (16) with the pre-expanded beads (15) through a filler (not shown). When the filling of the pre-expanded beads (15) is completed, the drain valves (8a) (8) of the male and female molds (1a) (1b)
b) and the control valve drive units (19a) and (19b) are operated to open the switching valves (6a) and (6b), and the pilot air is supplied to the control units (5a) and (5a) (or the switching valve (6a) (6b) is closed and the pilot air to the control part (5a) (5a) is shut off.) The control valves (5a) and (5b) are opened, and the steam from the steam source (10) is fed to the male and female molds. (1a) (1b) through the steam chamber (2a) (2b),
The male and female molds (1a) and (1b) are heated. Generally, since the maximum vapor pressure is supplied in this process, the control valves (5a) (5b)
Will be fully opened.

The steam supplied to the steam chambers (2a) and (2b) at the maximum steam pressure is discharged through drain pipes (20a) and (20b), and is discharged from the mold (1).
a) Heating of (1b) and discharge of air and drain in the molds (1a) and (1b) are performed. During this time, since the drain valves (8a) and (8b) are generally fully opened, the steam pressure in the steam chambers (2a) and (2b) is low and the steam chamber (2a) is operated by the pressure detection devices (4a) and (4b). The vapor pressure in (2b) is not detected. However, if the drain diameter is small, or if the drain outlet pipes (20a) (20b) are long, the back pressure may rise and the steam pressure may be detected. Good.

When the heating of the male and female molds (1a) and (1b) is completed,
Switch to << One-side heating process >> to heat the filled beads (15), discharge air and drain between beads (15),
(15) Uniform expansion is achieved. Here is a male (1a) drain valve
Open (8a), close the male (1a) control valve (5a), close the female (1b) drain valve (8b) and open the female (1b) control valve (5b). After the steam flows from the steam chamber (2b) of the female mold (1b) through the cavity (16) and heats the pre-expanded beads (15) in the cavity (16) at the steam pressure controlled by the flow rate or the feedback, the male mold It enters the steam chamber (2a) of (1a) and flows out of the male (1a) drain valve (8a).

During this time, the pressure in the steam chamber (2b) is detected by the pressure detector (4b) connected to the drain valve (8b). On the other hand, as the heating proceeds, the pre-expanded beads (1
5) swells and the flow of steam becomes worse. In other words, the steam room
The pressure of (2b) gradually increases, and this is detected.
Therefore, one-side heating is performed by the above-described feedback control. Then, if the vapor pressure is changed to a display device (2
Displayed in 4).

On the other hand, when the heating step has been completed, << reverse one-side heating >> is performed as necessary (in other words, reverse one-side heating may not be performed). In this step, the flow direction is reversed with respect to the flow direction of the one side heating, and the heating of the beads (15) and the discharge of air and drain between the beads (15) are performed as described above, and the further beads (15) are formed. Inflate. Close the male (1a) drain valve (8a), open the male (1a) control valve (5a), and open the female (1b) drain valve (8b) to control the female (1b) When the valve (5b) is closed, steam flows from the steam chamber (2a) of the male mold (1a) through the cavity (16), and the cavity (1
After heating the pre-expanded beads (15) in 6) from the opposite direction, they enter the female-type (1b) steam chamber (2b) and flow out of the female-type (1b) drain valve (8b).

During this time, as described above, the pressure detector (4a) connected to the drain valve (8a) changes the pressure from the steam chamber (2a) to (2b).
The steam pressure of the steam chamber (2a) flowing to the mold is detected and feedback-controlled by the above-described method, so that the reverse one-side heating is performed by the optimal steam pressure in the reverse one-side heating step in the mold (1). . On the other hand, at the end of the heating step, the beads (15) in the cavity are sufficiently foamed to form a foamed molded product (S), and there is almost no steam flow. Then, the process is switched to the next double-sided heating step.

The << double-sided heating step >> is a step mainly aimed at fusing the surface portion of the foamed molded article (S) by increasing the heating temperature by increasing the steam pressure. Male and female mold (1a) (1b) drain valve (8
a) Close (8b) and control valve (5a) for male and female molds (1a) (1b)
(5b) is opened, and steam is supplied to the steam chambers (2a) (2b) of the male and female molds (1a) (1b). In this case, the steam does not flow through the cavity (16), and the foam molding (S) is heated on both sides to sufficiently expand the foam molding.
The beads (15) on the surface of (S) are fused together. At this time, steam does not flow to both drain pipes (20a) (20b), but the pressure detectors (4a) (4b) are connected to the drain valves (8a) (8b) and the steam chambers (2a) (2b) The feedback control of the vapor pressure in the double-sided heating step is performed by the above-described method, and the double-sided heating is performed under the optimum condition.

When the double-sided heating is completed, the foam molded body in the cavity is cooled to a predetermined temperature by a suitable means such as vacuum cooling or water cooling. 《Cooling process》

After that, the mold is opened and the foamed molded product (S) is
It is taken out from (1) and the molding is completed. Such a cycle is repeated to form the foamed molded product (S). The die is exchanged before the lot is completed and changed to the next lot. At this time, the mold number of the replaced mold or the data of each step of the mold is input into the storage device (17b) via the keyboard (23), and the foam molding operation is started.

[0034]

As described above, according to the present invention, the presence of the control unit capable of performing feedback control so that the steam pressure supplied to the steam chamber is adjusted to the set value allows the foam molding machine to be set in accordance with the set conditions according to the mold. It was possible to quickly reproduce the precise steam pressure control of the valve, eliminate the complicated valve adjustment work that relied on the intuition of skilled workers, and significantly shorten the setup work. In addition, if the pilot pipe for detecting the vapor pressure connected to the pressure detecting device is connected to the drain valve upstream of the valve body of the drain valve, the connection portion between the drain hose and the mold during mold replacement ( That is, since it is detached at the base part), attachment / detachment of the pilot pipe is not required, and attachment / detachment of the pipes is simplified accordingly.

[Brief description of the drawings]

FIG. 1 is a piping system diagram of an embodiment according to the present invention.

FIG. 2 is a sectional view showing a connection position between a drain valve and a pilot pipe according to the present invention.

FIG. 3 is a diagram of a main piping system of a conventional example.

[Explanation of symbols]

 (1)… Die (1a)… Male (1b)… Female (2a) (2b)… Steam chamber (3a) (3b)… Steam piping (4a) (4b)… Pressure detector (5a) ( 5b) Control valve (6a) (6b) Switching valve (7a) (7b) Drain hose (8a) (8b) Drain valve (9a) (9b) Pipe line from drain hose to drain valve (10 ) ... Steam source (11a) (11b) (11a ') (11b') ... Bilot piping (20a) (20b) ... Drain piping (cont) ... Control unit

Claims (2)

[Claims] 1. A mold for foam molding having a steam chamber, a steam pipe connected to the mold, a pressure detection device for detecting a pressure in the mold, a control valve installed in the steam pipe, A drain pipe connected to the mold, and a control unit that performs feedback processing to compare the detection value of the pressure detection device with a previously input set value and adjust the steam pressure supplied to the steam chamber to the set value. A foam molding machine characterized by comprising: 2. The foam molding machine according to claim 1, wherein
A foam molding machine, wherein a pilot pipe for detecting a vapor pressure connected to a pressure detecting device is connected upstream of a valve body of a drain valve.