JPH02196616A - Method and device for injection-molding in press holding chamber of synthetic resin - Google Patents

Abstract

PURPOSE:To efficiently perform the plasticizing melting operation for the next injection-molding stage and to enhance a molding cycle by allowing press holding amount to act to a cavity side by the other injection pressure holding stage which immediately acts following the injecting operation via one part of the injection path of the injection-molding stage. CONSTITUTION:When a first-time injection-molding stage is performed and molten resin is filled in a cavity 4, an injection holding pressure correction supporting mechanism (I) immediately acts. When a plunger 14 is advanced by operation of a cylinder 16 and a piston 17, a second slant path 11c is interrupted. The injection holding pressure of injection operating action performed by an injection operating mechanism (II) is substituted as correction of pressholding by the injection holding pressure correction supporting mechanism (I). Thereby the injection operating mechanism (II) released from the holding pressure is returned to the actual condition and preparation such as plasticization and melting of resin for a raw material can be reperformed to inject the next molten resin.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention aims to improve production efficiency by improving the molding cycle, and also eliminates expensive injection holding pressure control using a computer and uses independent holding pressure control. A novel piston-cylinder structure consisting of an extremely simple piston-cylinder structure that has a mechanism, support means for pressure-holding correction provided in this pressure-holding mechanism, and opening/closing means for the pressure-holding process and plasticizing process, and a suckback mechanism. The present invention relates to a synthetic resin pressure chamber injection molding method and its apparatus.

(Prior art) Conventionally, in order to improve production efficiency and quality, this type of molding method and device has been equipped with an expensive computer to increase the price, increase the size, and increase the number of cavities. A method is being used to increase the number of items.

In order to speed up the molding cycle, the present inventor has developed, for example, Japanese Patent Application No. 62-232402 ``Method and device for spraying air into a mold in an injection molding machine''.
There is a technology.

(Problem to be solved by the invention) As mentioned above, if the number of cavities is increased in order to improve production efficiency, the price will increase due to the use of computers, and the molds and injection molding machines themselves will become larger, which will only lead to higher costs. However, this is unreasonable in terms of obtaining small molded products, and is not preferred as a molding method.

In other words, it is unavoidable that the plasticizing means becomes larger in proportion to the magnitude of the mold clamping force.In other words, the diameter of the cylinder tube and screw (plunger) used to plasticize and melt the raw resin becomes larger. During high precision molding, a computer detects and controls the position of the screw of the plasticizing mechanism far away from the cavity at the front of a large cylinder by a near-minimum distance of several sv or less, i.e. Encoder control had to be performed to perform multi-stage holding pressure and suckback operations.

Therefore, injection molding, which was the simplest and was used in the earliest injection molding equipment, evolved from one speed and one pressure, and multi-stage control such as four-speed injection speed, holding pressure and tertiary pressure became common with the use of computers. This control mechanism now accounts for half of the cost of an injection molding machine.

Furthermore, in the case of large-sized configurations, multi-stage pressure holding control after injection operation is necessary to maintain optimal screw movement control within a large-diameter cylinder, even with a small stroke operation of the screw. Since the amount of movement of the raw material resin increases, if the stroke operation is not performed delicately, voids may occur in the molded product due to insufficient holding pressure, or if the holding pressure is excessive, it may cause cracks due to the spacing between the molds. It can be said that it was unavoidable to install an expensive computer as a means of accurately detecting the stroke amount of the screw.

In addition, although the method and device for injecting airflow onto the mold surface are extremely effective in improving the molding cycle, other molding methods,
In particular, it is not a substitute for holding pressure during injection molding operations;
There was a problem in that no particular relevance could be recognized for making the plasticizing and melting means for the next step of preparation for molding work efficiently.

(Means for Solving the Problems) The present invention has been achieved by focusing on the above-mentioned points, and includes a series of synthetic resin molding operations such as opening and closing operations of molds, plasticizing and melting operations of synthetic resin raw materials, and injection molding operations. In the process of performing this, there is an injection molding process in which the molten synthetic resin raw material is injected into a cavity formed in a desired mold through a runner and an injection path leading to the runner, and an injection operation in this injection molding process. Subsequently, injection pressure is applied to the runner and the cavity through a part of the injection path of this injection molding process, and exerts a holding force in a holding pressure chamber formed by blocking the injection path side of the injection molding process. Consists of a holding process.

The synthetic resin pressure chamber injection molding method is further characterized in that stepless pressure holding control and suckback control are performed in the injection pressure holding step, and opening and closing operations of the injection path in the injection molding step are performed. In the process of performing a series of synthetic resin molding operations, such as opening and closing operations of molds, plasticizing and melting operations of synthetic resin raw materials, and injection molding operations, the molten synthetic resin raw materials are introduced into the cavities formed by the desired molds through runners and an injection molding step of injecting through an injection path leading to the runner, and following the injection operation of this injection molding step, acting on the runner and the cavity through a part of the injection path of the injection molding step, and It consists of an injection pressure holding step in which a holding pressure is applied in a holding pressure chamber formed by blocking the injection path side of the injection molding step, and a mold cooling step in which a cooling medium is injected onto the mold surface when the mold is opened, Furthermore, the present invention relates to a synthetic resin pressure holding chamber injection molding method, characterized in that stepless pressure holding control and suckback control are performed in the injection pressure holding step, and opening and closing operations of the injection path in the injection molding step are performed.

Further, the injection holding step of the present invention is controlled by a small plunger and a small piston that slides and controls the plunger, and the piston is bent to form a straight path, a first slope path, and a second slope path. Among the injection paths, the resin is slid in the first ramp, and the injected resin including opening and closing operations with the second ramp is kept under pressure in the pressure holding chamber and can be sucked back. It is something.

Further, the present invention includes a cavity formed by a mold that can be opened and closed, a desired runner through which a desired molten resin flows through a cavity formed by a mold that can be opened and closed, and a runner through which a desired molten resin is injected into the cavity. an injection path, an injection operating mechanism communicating with the injection path, and a holding force acting along a part of the injection path of the injection operating mechanism to a holding pressure chamber constituted by a part of the injection path and the runner; an injection holding pressure correction support mechanism for opening and closing the injection passage on the side of the injection operation mechanism by providing a synthetic resin pressure holding chamber; a mold cooling mechanism that injects a cooling medium into the mold; a cavity formed by the mold that can be opened and closed; a desired runner through which a desired molten resin flows through the gate of the cavity; an injection passage for injecting the liquid into the cavity, an injection operation mechanism communicating with the injection passage, and a maintenance mechanism that operates along a part of the injection passage of the injection operation mechanism and is composed of a part of the injection passage and the runner. The present invention is characterized by comprising an injection holding pressure correction support mechanism that applies holding pressure to the pressure chamber to open and close the injection path on the side of the injection operation mechanism, and furthermore, the holding pressure correction support mechanism of the present invention The injection holding pressure correction support mechanism is composed of a small plunger and a cylinder that controls the sliding movement of the plunger. The invention is characterized in that the injection path is slidable within the first slope and the communication with the second slope can be opened and closed in an adjustable manner.

A further object of the present invention is to provide a method and apparatus for injection molding a synthetic resin pressure chamber, characterized in that opening and closing operations are performed to adjust the degree of opening and closing of the injection path in the injection molding process.

The object of the present invention is to provide a new molding apparatus and method that returns to the one-speed, one-pressure system that was used in the early stages of the development of injection molding machines, and that also includes a pressure holding chamber with an automatic pressure holding function.

(effect) Mold opening/closing operation 1. Plasticizing operation of synthetic resin raw material.

During a series of synthetic resin molding operations such as injection molding operations, a desired amount of molten resin raw material is injected into a cavity formed by a desired mold. In other words, the moment the molten resin is injected into the cavity and pressure holding chamber through the nozzle and gate at the desired injection pressure and speed (one-speed l-pressure is sufficient) by an injection operation using a screw, etc., the molten resin is expanded. , compressed by injection pressure.

If the temperature and pressure are constant, the amount compressed at this time has a constant value that is a small amount (several percent) corresponding to the total volume of the cavity and the pressure holding chamber. In other words, it includes a very small amount that can also be called a holding pressure amount.

In this invention, immediately following this injection operation, the holding pressure is applied to the cavity side by another injection pressure holding process that operates through a part of the injection path of the injection molding process, so that the injection molding By shortening the working time of applying holding pressure in the process, it is possible to immediately start the plasticizing and melting operation for plasticizing and melting the synthetic resin raw material for injection in the mold to prepare for the injection molding operation.

In addition, in this injection pressure holding process, by using a part of the injection path, the injection path on the injection molding process side is closed, and the operation can be started immediately for plasticizing and melting the raw resin as described above. The suck back function can also be performed continuously after the pressure holding operation.

After completing the action of the injection pressure holding step and performing the suck-back operation, the injection path is closed again to enter plasticization metering, proceed to the first injection molding step, and after flI, the same operation can be repeated.

Second, by injecting the cooling medium onto the mold surface through the open path of the mold, the mold can be cooled more quickly and the mold opening time can be shortened.

〔Example〕

Examples of this invention are shown below.

First, Figures 1 and 2 (a), (b) and (C)
An embodiment of the present invention will be described based on the following.

1 is a fixed mold with gate 2 open, 3 is a saw fixed mold 1
The movable molds 1.3 and 1.3 move toward and away from each other, and a desired cavity 4 is formed by both molds 1.3. 5 is fixed mold l
A plurality of mold groups provided at the rear of the cavity 4
7. Place a part of the runner between the nozzle touch and the nozzle touch mentro. A runner 9 such as a manifold branch hole 8 is bored.

Reference numeral 10 denotes a nozzle connected to the touch control of the Yoshiki nozzle, and in the first diagram, it communicates with an injection path 11 in which an injection holding pressure correction support mechanism (I) and an injection operation mechanism (n) are combined.

That is, an injection operating mechanism (II) is provided along the same axial direction as the nozzle touch center of the fixed mold 1, and an injection holding pressure correction support mechanism ( I) is provided.

The injection path 11 includes a straight path 11a from the nozzle 10, a first slope path 11b passing through the axial center hole 12 of the injection holding pressure correction support mechanism (I), and a slope path 11b that passes through the axial center hole 12 of the injection holding pressure correction support mechanism (I), and a slope path 11b that passes through the axial center hole 12 of the injection holding pressure correction support mechanism (I), and a slope path 11b that passes through the axial center hole 12 of the injection holding pressure correction support mechanism (I). ) to the tip passage 13 of the second slope tic
The axial center hole of the injection holding pressure correction support mechanism (I)! By moving back and forth the small-sized brangeaux 14 that slides inside the buranjou 14, the -th side passage 11b and the second side passage 11c can be opened and closed. In addition, the degree of opening and closing is shown in Figure 2 (C).
The flow rate can be controlled freely as shown in the figure.

As a result, when picking up small items or a large number of items, the flow rate and flow rate can be controlled, making it comfortable.

Further, 15 of the injection operation mechanism (■) indicates an injection plunger or screw, and although steps such as plasticizing and melting the raw resin and supplying the raw material are omitted, conventionally known techniques are used for all of them.

And 16 of the injection holding pressure correction support mechanism (I),
A cylinder for driving the plunger 14, 17
indicates the piston, which is controlled by hydraulic pressure such as oil pressure.

X indicates a holding chamber, which includes a runner part 7, a manifold branch hole 8, a runner 9 of the window, and among the injection passages 11 of the injection operation mechanism (■) from the nozzle touch mentro, a straight passage 11a and a first slope passage 11b. refers to the space formed between

Reference numeral 21 indicates a measuring rod protruding from the opposite side of the piston 17 of the plunger 14 of the injection holding pressure correction support mechanism (I), and is a gauge capable of detecting and measuring the amount of movement of the fixed needle 22 and the fixed beam 22. 23 is parallel to the rod 21.

The action will be explained based on the above structure.

The fixed mold 1 and the movable mold 3 can be opened and closed using a normal mold opening/closing means to form a desired cavity 4.

Further, the injection operation mechanism (n) performs the function of a normal plasticizing and melting process of synthetic resin raw materials, and preliminarily measures and melts the synthetic resin raw materials in a state ready for injection.

On the other hand, the plunger 14 of the injection holding pressure correction support mechanism (I)
is moved backward, and the injection path 11 is maintained in a state where it can flow, that is, the first ramp flb and the second side channel 11c are maintained in a communicating state (see FIG. 1).

In this state, when the injection plunger or screw 15 of the injection operation mechanism (■) is operated to enter the injection molding process, the molten resin is transferred from the tip passage 13 to the second side passage 11c and the second slope passage 11b. , enters the runner 9 from the nozzle 10 through the injection passage 11 consisting of a straight path 11a, and is finally filled into the cavity 4 through the gate 2 to enable molding. Since no molten resin is contained, it goes without saying that the molten resin is first filled into the pressure holding chamber X and then the continuous molding operation is performed.

When the first injection molding process is performed and the cavity 4 is filled with molten mm, the injection holding pressure correction support mechanism (I) immediately operates to move the plunger 14 into the cylinder 1.
6. When moved forward by the action of the piston 17, the second side passage 11c
is shut off, and the injection holding pressure of the injection operation effect by the injection operation mechanism (n) is replaced by correction of holding pressure by the injection holding pressure correction support mechanism CI) (see Fig. 2 (a)).
. That is, the molten resin injected into the cavity 4 completes the injection and compression steps in a very short time, shrinks and solidifies as the mold 1.3 cools, and the volume of the molten resin decreases. The decreasing trace amount must be fed in correctively via the gate 2, which is still open. Otherwise, a trace of deficiency will become a void (picket), and an excess will become a paris. This step is carried out by the injection holding pressure correction support mechanism (I), but the minute amount correctedly supplied into the cavity 4 at this time is also called the holding pressure amount and requires delicate control.

In this way, the two injection holding pressure correction support mechanisms (1) plunger 14 directly presses the molten resin in the -th side path flb, and after injection, the injection holding pressure necessary for cooling solidification molding in the cavity 4 is applied to the injection holding pressure. The injection operation mechanism (CU), which has been released from the holding pressure, returns to its current state and performs the next process of plasticizing, melting, etc. the raw resin again. Preparations for injection can be made. As a result, the plasticizing device can be reduced to 1/2 or less of the conventional one.

Further, the injection holding pressure correction support mechanism (I) that has completed the operation of applying the holding pressure partially retreats its plunger 14 to communicate the first side path ttb and the second side path 11c to prevent suckback. The injection molding process can be continued, and the next injection molding operation can be resumed (Fig. 2 (b)).
reference).

In this case, it is possible to completely avoid molding defects such as pickling and uneven thickness that may occur during suckback, which is the most abhorrent problem in injection molding operations.

Then, substantially simultaneously with the suckback operation of the injection holding pressure correction support mechanism (I), the mold 1.3 is opened and the molded product molded in the cavity 4 can be taken out.

Continuous molding can be performed by repeatedly repeating the above steps.

Conventionally, the injection holding pressure process in the cavity was detected at the position of a thick screw in the space in front of the screw of the plasticizing mechanism far away, and the correction amount for holding pressure was determined. Since it is necessary to determine the amount of pressure, it is necessary to specify the position in 1/1 (Jam order) with a thick screw.For this reason, expensive encoder control has been used. The amount of holding pressure detected at the position (for example, φ5
Because the distance of 2.6 am can be converted and replaced with a small-diameter first ramp 11b that can increase the stroke amount by dividing the distance of 2.6 am with a screw of 8 a + m into three stages such as tertiary pressure, etc., and increasing the stroke amount, By using the gauge 23, the extremely small correction amount of 1/10 m+■ in the conventional screw position detection amount can be expanded to a length equivalent to 10 times, and it can be easily controlled manually, making effective computer control unnecessary. .

Next, another embodiment shown in FIG. 3 will be described.

In this embodiment, a mold cooling mechanism (m) using cooling medium injection is newly added to the configuration shown in the previous embodiment.

Therefore, the same reference numerals are given to the same or corresponding configurations as those in the above embodiment, and detailed explanation thereof will be omitted.

In the figure! Reference numeral 8 denotes an air flow passage hole having a nozzle portion opened in the mold opening surface 1a near where each cavity 4 of the fixed mold 1 is formed, and as shown in the figure, it is branched into three parts and is bored at an angle. A ventilation pipe 19 connects to an airflow controller including an airflow generator, temperature control, etc.

Similarly, in the vicinity of where each cavity 4 of the movable mold 3 is formed, three air flow passage holes 18 each having a nozzle opening are formed in the mold opening surface 3a at an angle and are branched into three places.
Two ventilation pipes 19 are connected to the openings on both sides of the end face of the mold to connect with the air flow controller.

The air flow passage hole 18 may be arranged so that the nozzle portion is closed when the molds 1 and 3 are closed, and the nozzle portion is opened when the molds 1 and 3 are opened.

Since the configuration is as described above, molds 1 and 3 are installed as shown in Figure 3.
is in the open state, the mold cooling mechanism (m) works, and the airflow obtained from the airflow controller passes through the passage pipe 19 and enters the airflow passage hole 1.
8 and is injected from the nozzle portion, the airflow reaches the mold opening surface 1a.

3a, the mold can be rapidly cooled, and the gate 2 is also cooled at the same time, thereby preventing the so-called dripping phenomenon in which molten resin flows down from the surface 1a, and the stringing phenomenon in which a thread is pulled from the gate 2. You can also do that.

In addition, sufficient heat dissipation and cooling can be achieved in a short time by forced cooling to areas with small volume such as the uneven pattern of the cavity 4 of the mold 1.3, protrusions, or sharp points, resulting in good shape retention. Even if the mold is worn out, the shape of the cavity 4 does not collapse, and it can maintain its durability for a long time.

In addition to being able to shorten the cooling time of the mold in the mold opening path, the injection holding pressure correction support mechanism (I)
The holding pressure (Fig. 2 (a)) and suckback (Fig. 2 (b)) allow the injection operation mechanism (n) to quickly move to its original state, and the next injection molding operation can be carried out efficiently. Through preparation, so-called high-speed molding can be achieved to the utmost.

In the figure, 20 is an integral part of the hot runner of the runner part 7. The integrated hot runner 20 can open and close the so-called gate 2 by intermittently raising and lowering the temperature of the tip portion facing the gate 2 in connection with the injection molding operation to solidify or melt the resin at the gate portion. It can also be configured.

Furthermore, the configuration of the injection path 11 is not limited to the configuration shown in the drawings, but can be provided as a desired bent structure.

Although runnerless injection molding was described in the above-described embodiments, cordless runner injection molding can also be performed.

(Effects of the Invention) According to this invention, the injection path on the injection molding process side is partially closed at the same time as the injection holding pressure process starts, so it is entered into the plasticity meter 1 immediately after the start of injection.Therefore, it can be used for plasticity measurement. Compared to the conventional method, which starts after the shut-off valve closes, the plasticization measurement can be performed for more than twice as long, so the time can be more than doubled.

In other words, there is a remarkable effect that less than half the capacity is required compared to the conventional one.

In the past, in pursuit of high-cycle molding, the screws were given high-speed rotation to cause molecular breakage, resulting in high horsepower.
Due to the molecular shear heat, the temperature of the resin when it exited the nozzle was about 10% higher than the indicated temperature of the heating tube.

This 10% higher resin temperature also resulted in a 10% cooling delay when the resin was cooled in the mold, which actually hindered high-cycle molding.

With this invention, more than twice as much time can be spent, so the screw rotation speed can be reduced to the minimum necessary, thereby suppressing the generation of shearing force that hinders high-cycle molding. It can also prevent sharpening. In addition, the horsepower of the drive source motor can be reduced, and the injection mechanism can be miniaturized to about the size of the mold clamping force that was thought to be commensurate with the horsepower.

Furthermore, in the past, the performance of an injection molding machine was expressed in terms of mold clamping force tonnage, and the corresponding plasticizing capacity was determined by the machine itself.

The present invention significantly breaks the conventional balance between mold clamping force and plasticizing ability, and can reduce the plasticizing ability by about half.

According to this invention, during the injection molding process, following the injection molding operation, an injection holding pressure step is included to apply a holding pressure for injection molding, so that plasticization and melting for the next injection molding process is included. The operation can be performed independently, effectively and efficiently, and the so-called molding cycle can be significantly improved.

Further, according to the present invention, since a mold cooling mechanism using airflow is provided to forcibly cool the mold surface, the mold can be cooled quickly, and furthermore, the layer molding cycle can be shortened. It is possible to achieve the most efficient synthetic resin molding process.

Moreover, the overall configuration is not particularly complicated and can be simply incorporated into a conventional device, so the cost is not high and it can be provided at an extremely low cost.

[Brief explanation of the drawing]

FIG. 1 is an explanatory side view showing an embodiment of the synthetic resin injection molding apparatus according to the present invention, showing a main part in longitudinal section, FIG. 2(a),
(b) and (C) are explanatory cross-sectional views showing the three bad aspects of the same essential part, and FIG. 3 is a partially cutaway side explanatory view of the essential part showing the other side. I --- Injection holding pressure correction support mechanism ■ --- Injection operation mechanism 2 --- Gate 3 --- Movable mold 4 --- Cavity 10 --- Nozzle 11 --- One injection path 11 a - = = Straight path 11b --- First side path 11 c --- Second side path 12 --- Shaft center hole 13 --- Tip passage 14 --- Blunger 7 --- Piston 21 --- Measuring rod 22 --- Fixed needle 23 --- Gauge

Claims (8)

[Claims] (1) In the process of performing a series of synthetic resin molding operations such as opening and closing operations of the mold, plasticizing and melting operations of the synthetic resin raw material, and injection molding operations, the molten synthetic resin raw material is poured into the cavity formed by the desired mold. an injection molding step in which injection is injected through a runner and an injection path leading to the runner, and following the injection operation of this injection molding step, the injection molding is injected into the runner and cavity through a part of the injection path of this injection molding step. and an injection pressure holding step in which holding pressure is applied in a holding pressure chamber formed by blocking the injection path side of the injection molding process, and furthermore, the injection pressure holding step performs stepless pressure holding control and suckback control. . A synthetic resin pressure chamber injection molding method, characterized in that an injection path in the injection molding step is opened and closed. (2) The synthetic resin pressure chamber injection molding method according to claim 1, characterized in that opening and closing operations are performed so that the degree of opening and closing of the injection path in the injection molding process can be adjusted. (3) In the process of performing a series of synthetic resin molding operations such as opening and closing operations of the mold, plasticizing and melting operations of the synthetic resin raw material, and injection molding operations, the molten synthetic resin raw material is poured into the cavity formed by the desired mold. An injection molding process in which injection is carried out through a runner and an injection path leading to the runner, and following the injection operation of this injection molding process, injection is carried out through a part of the injection path in the second injection molding process to the runner and the cavity. and a mold cooling step in which a cooling medium is injected onto the mold surface when the mold is opened. It consists of a process,
A method for injection molding a synthetic resin pressure chamber, further comprising stepless pressure holding control and suckback control in the injection pressure holding step, and opening and closing operations of the injection path in the injection molding step. (4) The synthetic resin pressure chamber injection molding method according to claim 3, wherein the opening and closing operations are performed so that the degree of opening and closing of the injection path in the injection molding process can be adjusted. (5) The injection holding step is controlled by a small plunger and a small piston that slides and controls the plunger, and the straight path is formed by bending the piston.
Of the injection path consisting of a first slope and a second slope, the injected resin can be slid in the first slope and opened/closed with the second slope to hold the pressure in the pressure holding chamber and can be sucked back. 4. The synthetic resin pressure chamber injection molding method according to claim 1 or 3. (6) a cavity formed by a mold that can be opened and closed;
A desired runner through which a desired molten resin flows through the gate of the cavity; an injection path through which the molten resin is injected into the cavity; an injection operating mechanism communicating with the injection path; Injection holding that operates along a part of the injection path and applies a holding pressure to a pressure holding chamber constituted by a part of the injection path and the runner to open and close the injection path on the injection operation mechanism side. A synthetic resin pressure chamber injection molding device comprising a pressure compensation support mechanism. (7) A mold cooling mechanism that injects a cooling medium onto the mold surface, a cavity formed by the mold that can be opened and closed, a desired runner that communicates with the gate of this cavity and through which a desired molten resin flows; an injection passage communicating with the runner and injecting molten resin into the cavity; an injection operating mechanism communicating with the injection passage; A synthetic resin pressure chamber injection molding device comprising: an injection holding pressure correction support mechanism that applies a holding pressure to a pressure chamber formed by a pressure chamber and opens and closes an injection path on the side of the injection operation mechanism. . (8) The injection holding pressure correction support mechanism is composed of a small plunger and a cylinder that slides and controls the plunger, and is connected to a straight path formed by bending the piston, a first slope path, and a second slope path. The synthetic resin pressure chamber injection according to claim 4 or 5, characterized in that the synthetic resin pressure holding chamber is configured to slide in the first ramp of the injection passages and to be able to open and close the communication with the second ramp in an adjustable manner. Molding equipment.