JPH0750184Y2 - Material supply device for resin molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a material supply device for supplying a resin material to a resin molding machine.

[Prior Art] Conventionally, as a resin molding machine, there has been known one in which two kinds of resin materials are mixed and kneaded in a molding machine and then injected into a mold molding space, for example, Japanese Patent Laid-Open No. 61-61. In JP-32727, a colorant (masterbatch) is added to and mixed with an uncolored base material (natural material), and the mixed material is injected into a mold molding space to obtain a colored resin molded body. Things are disclosed.

In this case, a hopper for supplying the main agent is attached to the resin molding machine, and a supply pipe for supplying the colorant is arranged so that one end of the supply pipe opens into the hopper, and the molding is performed from the colorant supply pipe. A predetermined amount of colorant is supplied into the machine. That is, the other end of the colorant supply pipe is connected to a colorant supply device which measures a predetermined amount of the colorant and supplies the colorant to the molding machine side, as will be described later in detail. When the measurement of the resin material is started, the colorant sent from the colorant supply device to the colorant supply pipe side is supplied into the molding machine together with the main agent stored in the hopper.

The colorant supply device is provided with a metering container that stores a certain amount of colorant and measures the colorant to be supplied per cycle by, for example, rotation of a feeder. This metering container is usually different. Multiple colorant tanks are connected to store each type of colorant. Then, when the lot production of a certain molded product is completed and then the lot production of a different type of molded product is performed, the molding dies are exchanged, and if the type of colorant to be added is different, the colorant tank is connected. To switch colors.

By the way, in the above-mentioned measuring container, in general, in order to detect the level of the colorant in the container, an upper limit level sensor for detecting that the colorant is stored at a predetermined upper limit level or more in the container, and the colorant. Is provided with a lower limit level sensor for detecting that the level has dropped below a predetermined lower limit level, and during the production of a lot, the lower limit level sensor detects this when the level of the colorant drops to the above lower limit level, The colorant is replenished from the tank side storing the colorant to the measuring container side up to the upper limit level. The lower limit level is set so that even if the colorant in the measuring container drops to this level, the colorant can be supplied for a predetermined number of shots. The supply of colorant to the side is not interrupted.

[Problems to be solved by the invention] However, when the level of the coloring agent in the measuring container is lowered to the lower limit level near the end of the lot production of a certain molded article, the conventional coloring agent is increased to the upper limit level. When replenishment is completed and the above lot production is completed and the color is changed,
It is necessary to discharge from the container the old colorant that has been consumed less since it was replenished and stored near the upper limit level. Further, there is a problem that it takes a long time to change colors because this discharging work takes time.

By the way, when finishing the lot production of a certain molded product and switching the production lot to a different type of molded product, if the type of colorant to be added is different, the old colorant is discharged from the measuring container and the container is replaced. After emptying, a new colorant is stored in the measuring container, but to start production of a new lot, it is sufficient that the colorant has been stored up to a certain level, and it is not always necessary to store the colorant from the initial start up to the upper limit level. There is no need to store it. However, in the past, since the new colorant was stored up to the upper limit level of the measuring container before the production of a new lot was started, it would take an extra time to supply the colorant to the measuring container. There was a problem that the production start of a new lot was delayed by that much.

Further, when the level of the colorant in the measuring container drops to the lower limit level near the end of lot production of a certain molded product, the colorant is conventionally replenished to the upper limit level. Therefore, when the lot production is completed and the color is changed, the colorant consumption after replenishment is small.
There is a problem that it takes a long time to change the color because it takes a long time to discharge the old colorant from the container since the old colorant is stored in the measuring container up to the upper limit level.

In other words, when shortening the production lot switching time, even if the time required for setup change on the resin molding machine side is shortened by automating the exchange of molding dies, etc. There was a problem that it was difficult to realize sufficient time reduction as a whole.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a material supply device for a resin molding machine that can reduce the color change time accompanying the production lot change.

[Means for Solving the Problems] Therefore, the first invention of the present application is to provide a measuring container for measuring and storing the resin material to be supplied into the resin molding machine, and a material for supplying the resin material to the measuring container. In a material supply device for a resin molding machine including a tank, an upper limit level sensor for detecting that the resin material is stored in a predetermined upper limit level or more in the measuring container, and a resin material level for a predetermined lower limit. In addition to providing a lower limit level sensor that detects that the resin material has fallen below a level and an intermediate level sensor that detects that the resin material is stored at a predetermined intermediate level or more between the upper limit level and the lower limit level, At the time, the measuring container is supplied with resin material up to the upper limit level according to the detection signal of the lower limit level sensor, while at the start of production of a new lot, the measuring container is filled with resin material. A control means for supplying the charge to the above intermediate level is provided.

A second invention of the present application is a material for a resin molding machine including a measuring container for measuring and storing a resin material to be supplied into the resin molding machine, and a material tank for supplying the resin material to the measuring container. In the supply device, in the measuring container, an upper limit level sensor that detects that the resin material is stored above a predetermined upper limit level, and a lower limit that detects that the level of the resin material has dropped below a predetermined lower limit level. A level sensor and an intermediate level sensor for detecting that the resin material is stored at a predetermined intermediate level or higher between the upper limit level and the lower limit level are provided, and the detection signal of the lower limit level sensor is normally provided. According to the above, the resin material is supplied to the measuring container up to the upper limit level, while when the number of remaining shots in the production lot is equal to or less than a predetermined value, the measuring container is filled with the resin material. It is provided with a control means for supplying to the level.

[Effect of the Invention] According to the first invention of the present application, the measuring container is provided with the intermediate level sensor in addition to the upper limit and lower limit level sensors, and the material supply device is provided with the control means. At the start of production, the resin material supplied to the measuring container can be limited to the intermediate level, and the initial material supply time can be shortened as compared with the case where the resin material is conventionally supplied to the upper limit level. it can. As a result, the color change time can be shortened, and a new production lot can be quickly started up to improve productivity.

Further, according to the second invention of the present application, since the measuring container is provided with the intermediate level sensor in addition to the upper and lower limit level sensors and the material supply device is provided with the control means, the remaining shots of the production lot are provided. When the number is less than a predetermined value, the resin material supplied to the weighing container can be limited to the intermediate level, and color change due to the switching of the production lot compared to the conventional case where the resin material was supplied to the upper limit level. It is possible to shorten the discharge time of the old colorant from the measuring container and reduce the color change time. As a result, it is possible to shorten the production lot switching time and improve the productivity.

[Embodiment] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings in the case of being applied to a material supply device of a resin molding machine for injection molding a colored resin molded product.

FIG. 2 is an overall configuration diagram showing an outline of the resin molding machine and the material supply apparatus for the resin molding machine according to the present embodiment. As shown in FIG. A main agent hopper 8 for supplying a colored powdery or granular main agent (natural material) is attached, and a main agent tank (not shown) for supplying the stored main agent into the hopper 8 is connected to the hopper 8. . A colorant supply pipe 19 for supplying a colorant (masterbatch) is arranged below the main agent hopper 8, and one end of the supply pipe 19 is opened downward in the hopper 8. , The other end is colored with a molding machine 1
It is connected to a colorant supply device 10 for supplying the side.

As will be described later in detail, the colorant supply device 10 stores, for example, a powdery or granular colorant and compresses the colorant to be supplied per metering cycle by compressed air by the molding machine 1 side. The colorant pressure-fed from the colorant supply device 10 is supplied to the feed pipe.
It is guided to a cyclone 18 via 17, and the colorant and air are separated by this cyclone 18, and only the colorant is sent to a colorant supply pipe 19 opened in the main agent hopper 8 and from this supply pipe 19. It is supplied into the molding machine 1 by natural fall together with the main agent.

The resin molding machine 1 is of the well-known in-line screw type, and has a cylindrical body 2
The main part includes a screw 3 that is inserted into the main body 2 so as to be movable back and forth and rotatable about an axis, an injection cylinder 5 that causes the screw 3 to perform an injection operation, and a drive motor 6 that rotationally drives the screw 3. Drive mechanism 4 configured as
By rotating the screw 3 by the drive motor 6, the resin material is dropped / supplied from the hopper 8 side into the cylinder body 2, and the screw 3 retracts in the cylinder 2 and retracts to a predetermined position. Then, the rotation operation of the screw 3 is stopped, and the measurement and supply of the resin material into the cylinder body 2 is completed.

That is, after the end of the previous cycle, the screw 3 in the forward position is rotated, and the screw 3 is retracted to a predetermined retracted position in accordance with this rotation, whereby the resin material for one cycle is measured and supplied. . Further, in this process, the resin material in the cylinder 2 is plasticized by the rotating operation of the screw 3 and the heating from the outside of the cylinder 2. Then, by operating the injection cylinder 5 from this state and advancing the screw 3 to a predetermined advancing position, the resin material in the cylinder 2 is injected from the nozzle portion 2a toward the mold molding space (not shown). It is like this.

The drive mechanism 4 of the molding machine 1 and the colorant supply device 10 are both connected to a control unit 30 that controls the operation of the resin molding machine 1 and the material supply to the molding machine 1, and on the molding machine 1 side. A command signal is output from the control unit 30 to the colorant supply device 10 in response to the start of the measurement, and the device is driven to supply a predetermined amount of colorant to the molding machine 1 side. There is.

As shown in FIG. 1, the colorant supply device 10 stores a powdery or granular colorant and measures the colorant to be supplied per one metering cycle.
And a feeder 15 that collects the colorant from the weighing machine 11 by a hopper 16 and sends the colorant under pressure to the molding machine 1 side by compressed air.

The weighing machine 11 includes a weighing container 12 for storing a colorant and a coil-shaped feeder 13 which is rotationally driven by an electric motor 14, and the rotation of the feeder 13 causes the colorant in the weighing container 12 to be fed by a feeding device. It is sent to the 15 side. At this time, the feeder
By controlling the rotation amount of 13, it is possible to meter the amount of the colorant to be added per molded article (that is, the amount to be supplied per metering cycle).

Replenishment pipes 21a, 21b, 21c extending from a plurality of colorant tanks Ta, Tb, Tc respectively storing different colorants A, B, C are connected to the upper portion of the measuring container 12, and each colorant is Replenishment shutters 22a, 22b, 22 provided on the tanks Ta, Tb, Tc
By switching the open / closed state of c, the connection state of the measuring container 12 and each colorant tank Ta, Tb, Tc can be switched. In addition, shutters 23a, 23b, and 23c for discharge are installed at the bottoms of the colorant tanks Ta, Tb, and Tc, respectively.

On the other hand, at the bottom of the measuring container 12, a discharge shutter that is opened when the colorant in the measuring container 12 is discharged such as when changing colors.
25 is provided, and the shutter 25 is provided with a cylinder device 25d for opening and closing the shutter. Below the discharge shutter 25, a hopper 26 for collecting the colorant discharged from the measuring container 12 is installed, and on the downstream side of the collecting hopper 26, the colorant discharged from the measuring container 12 is colored. Agent tank
Collecting pipes 28a, 28b, 28c for collecting respectively Ta, Tb, Tc are arranged, and between the respective collecting pipes 28a, 28b, 28c and the collecting hopper 26, the collecting pipes 28a, 28b, 28c are collected depending on the kind of the coloring agent. A branching device 27 for switching the connection state between the hopper 26 and the recovery pipes 28a, 28b, 28c is provided.

In the present embodiment, in the measuring container 12, in order to detect the level of the coloring agent in the container 12, the upper limit level sensor 31 for detecting that the coloring agent is stored in the container 12 at a predetermined upper limit level or higher. And a lower limit level sensor 33 for detecting that the colorant level has dropped below a predetermined lower limit level,
An intermediate level sensor 32 for detecting that the colorant is stored at a predetermined intermediate level or more between the upper limit level and the lower limit level is provided, and these level sensors are provided.
All 31, 32, 33 are electrically connected to the control unit 30 which controls the operation of the resin molding machine 1. A drive device for the replenishment shutters 22a, 22b, 22c and discharge shutters 23a, 23b, 23c of the colorant tanks, and the discharge shutter 25d of the weighing container 12, and the branch device 27, the control unit 30. Is connected so that signals can be transmitted and received.

Then, during lot production, the lower limit level sensor 33 detects that the level of the colorant drops to the above lower limit level during normal production, and stores the colorant based on the detection signal of the lower limit level sensor 33. Control is performed so that the colorant is replenished from the tank side to the measuring container 12 side up to the above upper limit level. The lower limit level, even if the colorant in the measuring container 12 is lowered to this level, the level is set so that the colorant can be supplied for a predetermined number of shots, at the time of replenishment to the measuring container 12, The supply of the colorant to the molding machine 1 side is not interrupted.

Further, in this embodiment, when the production of a new lot is started, and when the number of remaining shots during the lot production becomes less than or equal to a predetermined value (for example, 10 shots), the colorant is replenished to the measuring container 12. The amount is limited to the above intermediate level.

Hereinafter, the supply of the colorant to the measuring container 12 in the colorant supply device 10 will be described.

FIG. 3 is a process explanatory diagram in which the horizontal axis shows time for explaining the supply control of the colorant to the measuring container 12, and as shown in this figure, the injection molding is performed by the molding die D. When the production of the lot of the molded product to be performed is started and a predetermined shot (for example, 5 shots) progresses, the colorant is supplied to the measuring container 12 based on the detection signal of the lower limit level sensor 33. In this case, the colorant is supplied only to the above intermediate level at the start of lot production.
For replenishment after production is started,
The colorant is replenished up to the upper limit level.

Further, when the production process progresses and the number of remaining shots reaches a predetermined value (for example, 10 shots), the control unit 30 outputs a switching signal to switch the colorant supply level from the upper limit level to the intermediate level. The control unit 30 includes
The number n (that is, the total number of shots) of molded products to be produced in the lot is stored in advance, and the remaining shots are obtained by counting the number of shots at that time from the number of rotations of the screw 3 or the number of injection operations. The number is calculated.

After the switching signal is output, if the colorant level falls below the lower limit level, replenishment up to an intermediate level (for example, replenishment for 5 shots) is performed. And
When the total number of shots n has been reached, the operation of the resin molding machine 1 is stopped, the molding die is replaced with the mold E for the new production lot, and the color of the colorant is also changed.

That is, as shown in the flowchart of FIG. 4, first, in step # 1, the old colorant is discharged from the measuring container 12. In this case, after the remaining shots are 10 shots or less at the end of the previous lot, the replenishment is performed only up to the intermediate level, so that the residual amount of the colorant is small and the colorant can be quickly discharged.

Next, in step # 2, the inside of the weighing container 12 is cleaned using, for example, compressed air. Then, following this cleaning, in step # 3, a new colorant for a new lot is supplied to the weighing container 12. At this time, the supply amount is limited to the intermediate level of the measuring container 12, and the supply can be completed in a short time.

After that, in step # 4, the electric motor 14 is driven to start the initial weighing of the new lot by the weighing machine 11. That is, the color change accompanying the change of the production lot is completed.

After the color change is completed, the branching device 27 is operated to collect the old colorant for the previous lot into a predetermined colorant tank (steps # 5 and # 6).
Incidentally, in the past, the operation of collecting the old colorant by the operation of this branching device was performed between the cleaning operation of the measuring container 12 in step # 2 and the new colorant supply operation in step # 3.
In the present embodiment, since the color change with high process flexibility is completed, the color change time can be shortened also in this respect.

As described above, according to the present embodiment, the measuring container 12 is provided with the intermediate level sensor 32 in addition to the upper and lower limit level sensors 31 and 33. Since the colorant supply amount when the level of the colorant in the inside falls below the lower limit level, the initial colorant supply time is longer than that in the case where the colorant level is conventionally supplied to the upper limit level. Can be shortened. Even when the number of remaining shots in the production lot is less than or equal to a predetermined value, the replenishment amount of the colorant is similarly limited to the above intermediate level. The discharge time of the colorant from the measuring container 12 can be shortened. Furthermore, more preferably, since the old colorant is collected in the tank as an external setup after the color change is completed, it is possible to quickly start the production of a new lot.

As a result, it is possible to shorten the color changing time when changing the production lot and improve the productivity.

It should be noted that the above-mentioned embodiment was applied to the material supply device of the resin molding machine for injection-molding the colored resin molded product, but the present invention is not limited to the above case, and other resin molding machines may be used. It can also be effectively applied to a material supply device for.

[Brief description of drawings]

FIG. 1 is an equipment configuration diagram showing an outline of a material supply device according to an embodiment of the present invention, and FIG. 2 is an overall configuration diagram showing an outline of a resin molding machine and its material supply device according to the embodiment described above. FIG. 4 is a process explanatory diagram of the production lot according to the above-described embodiment, and FIG. 4 is a flowchart of the color changing process according to the above-described embodiment. 1 ... Resin molding machine, 12 ... Measuring container, 30 ... Control unit, 31 ... Upper level sensor, 32 ... Intermediate level sensor, 33 ... Lower level sensor, Ta, Tb, Tc ... Colorant tank .

Claims (2)

[Scope of utility model registration request] 1. A material supply device for a resin molding machine, comprising: a measuring container for measuring and storing a resin material to be supplied into the resin molding machine; and a material tank for replenishing the measuring container with the resin material. An upper limit level sensor for detecting that the resin material is stored at a predetermined upper limit level or more in the measuring container,
A lower limit level sensor that detects that the level of the resin material has dropped below a predetermined lower limit level, and an intermediate that detects that the resin material is stored above a predetermined intermediate level between the upper limit level and the lower limit level. In addition to providing a level sensor, normally, the resin material is replenished to the measuring container up to the upper limit level according to the detection signal of the lower limit level sensor, while at the start of production of a new lot, the measuring container is filled with the resin material at the intermediate level. A material supply device for a resin molding machine, which is provided with control means for supplying up to. 2. A material supply device for a resin molding machine, comprising: a measuring container for measuring and storing a resin material to be supplied into the resin molding machine; and a material tank for supplying the resin material to the measuring container. An upper limit level sensor for detecting that the resin material is stored at a predetermined upper limit level or more in the measuring container,
A lower limit level sensor that detects that the level of the resin material has dropped below a predetermined lower limit level, and an intermediate that detects that the resin material is stored above a predetermined intermediate level between the upper limit level and the lower limit level. In addition to providing a level sensor, the measuring container is normally replenished with resin material to the upper limit level in accordance with the detection signal of the lower limit level sensor, while the remaining number of shots in the production lot is below a predetermined value A material supply device for a resin molding machine, comprising a control means for replenishing the resin material to the above intermediate level.