JP2734313B2 - Casting method and apparatus for rubber products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to air and gas remaining or generated in a mold or a material when a resin or liquid rubber is mixed and injected at the time of molding and the resin or liquid rubber is cured and vulcanized. It relates to the manufacturing method to discharge.

[0002]

2. Description of the Related Art As a method of curing and vulcanizing a resin or liquid rubber without bubbles (void dressing), a method using a pressurized can and a method using a batch type vacuum casting apparatus have been known. ing.

In the former method, after injecting a resin or liquid rubber into a mold or the like, the resin or liquid rubber is put into a pressurized can before they are cured.
Introduce nitrogen gas (N ₂ ) or compressed air, and a few kgf / cm
^This is a manufacturing method in which the bubbles are apparently made inconspicuous by maintaining the pressure at ² and reducing the volume of the bubbles. Also,
The latter method is a method in which all or a part of the mixing / injection device and a mold and a grinder are confined in a closed container, the closed container is vacuum-evacuated, and material injection and preliminary curing / vulcanization are performed in a vacuum state.

[0004]

However, in the former method using a pressurized can, only the void is reduced (for example, if the effect of the viscosity of the material is neglected, it is 4 kgf / cm by the Boyle-Charles law). ^When a pressure of ² is applied, the volume of the void is 1 / the value at a normal pressure of 1 kgf / cm ^2.
It becomes 5 in size. ), Removal of essentially void is not possible, fine small voids would remain. In addition, there is a drawback in that the size of the apparatus becomes large and the vessel becomes a pressure vessel, so that safety management becomes complicated.

The latter method of injecting a material in a vacuum atmosphere in a closed vessel is the best method for preventing the generation of voids. However, since the mixing and pouring apparatus is installed in the closed vessel, this apparatus is not suitable. The scale becomes large, and the maintenance of the device becomes complicated. In addition, when part of the casting device is outside the sealed container, a pressure difference occurs between the inside and the outside of the sealed container, making it difficult to control the casting amount and mixing ratio, and at the same time, structurally simple sealing. Since the structure is not used, leakage is liable to occur, and it is difficult to maintain the degree of vacuum. Furthermore, since this process is a batch operation,
There are problems such as interlocking with the front and rear devices and difficulty in continuous automation.

[0006] The present invention has been made in view of such a point, mixing and pouring under normal pressure into a mold and slab, immediately transfer only the mold and slab into a closed container, and vacuum-suction to eliminate voids. It becomes possible to cure and vulcanize resin and liquid rubber. At the same time, since this process requires only a small vacuum vessel (vacuum capsule) with a simple structure, a continuous and automatic molding process can be performed by connecting it to the front and rear devices by a transfer system and a rubber product casting method. The purpose is to provide.

[0007]

According to the present invention, a resin or liquid rubber is injected into a mold or the like at normal pressure by means of a mixing / injection device, and then the molding or the mold is immediately transferred to a closed container, and the closed container is removed. by vacuum suction, gas or air contained in the resin or liquid rubber or molded Hire (void) discharged, thereafter, return the sealed container to atmospheric pressure, the
This is a method for producing a resin or liquid rubber voidless mold by a vacuum device which takes out a molding and a grind from a closed container, puts the molding and grind into a heat treatment device, and cures the molding and grind.

[0008] Further, the present invention relates to a molding and shaving device,
A preheating device, a mixing / injection device, a closed vessel (vacuum capsule) and a heat treatment device are sequentially arranged, and a resin or liquid rubber is formed by the mixing / injection device in a casting device in which these devices are connected by a conveyor. The molding and shaping material mixed and injected at normal pressure is transferred to the bottom plate of a sealed container (vacuum capsule), and the bottom plate is raised to house the shaping material in the sealed container.
At the same time, the airtight container is closed, the degree of vacuum is maintained at the predetermined degree of vacuum for a predetermined time, and then the pressure is returned to normal pressure and molding is immediately performed.
This is a casting and molding apparatus for rubber products, characterized in that hardening and vulcanization are carried out by feeding the rubber into a heat treatment apparatus.

[0009]

[Effect] Immediately after the mixing / injection device, a closed container (vacuum capsule) is installed independently from the mixing / injection device. Immediately after the closed container, a heat treatment (curing / curing) device will be installed. And mixing and injection device and sealed container (vacuum capsule)
And the heat treatment equipment are connected by a transport system. The mold or mold into which the resin or liquid rubber has been injected under normal pressure by the mixing and injection device is immediately transferred to a vacuum capsule and vacuum-suctioned. After reaching a predetermined degree of vacuum and maintaining the same for a predetermined time, the sealed container (vacuum capsule) is broken in vacuum to introduce outside air and return to normal pressure. Immediately thereafter, by feeding the heat treatment apparatus to the heat treatment apparatus by the transfer system, the curing and vulcanization of the voidless material can be continuously and automatically performed.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of the entire line including the front and rear devices of the device applied to the method of casting and molding a rubber product according to the embodiment. That is, the shaping and shaping (mold) 3 charged into the preheating device 2 by the shaping and shaping (mold) feeding device 1
Is raised to a predetermined temperature while passing through. In response to a command from the centralized control panel 4 for the entire line, the molding and shaping (mold) 3 carried out of the preheating device 2 passes through the conveyor 5 and then goes below the mixing / injection device 6, where the resin or liquid rubber is discharged. Injected. Then, it is immediately transferred under the closed container (vacuum capsule) 8 by the transfer conveyor 5 and the transfer device 7. The bottom plate 9 of the sealed container (vacuum capsule) 8 rises, and the molding and shaping (mold) 3 into which the material is injected is a sealed container (vacuum capsule).
8 sealed. At the same time, the vacuum pump 10 is started, and the airtight container (vacuum capsule) 8 is evacuated. The inside of the sealed container (vacuum capsule) 8 reaches a predetermined degree of vacuum, and after maintaining the degree of vacuum for a predetermined time, the vacuum pump 10 is stopped, outside air is introduced, and the pressure returns to normal pressure. When the sealed container (vacuum capsule) 8 is opened, the transfer device 7 takes out the mold 3 and transfers it to the heat treatment device conveyor 11. Then, after performing heat treatment and curing and vulcanization at a predetermined temperature for a predetermined time in a heat treatment apparatus 12, molding and shaping (mold) are performed.
3 is paid out by the paying-out conveyor 13 and is die-cut to obtain a finished product.

Next, a specific example of the sealed container (vacuum capsule) 8 will be described in detail with reference to FIG. The mold 3 which has been conveyed by the conveyor 5 is a stopper 14
And then lifted by the transfer device 7,
It is lowered onto the bottom plate 9 of the sealed container (vacuum capsule) 8. The transfer device 7 moves forward and stops. Next, the bottom plate 9 on which the forming and shaping (mold) 3 is placed is pushed up by the cylinder 15 and is overlapped on a closed container (vacuum capsule) 8 to be sealed. At the same time, the vacuum pump 10 starts, the outside air introduction leak valve 16 closes, the vacuum valve 17 opens, and vacuum suction starts.

A throttle valve 1 is provided for each of the inlet pipe and the suction pipe.
8 and 19 are provided so that the speed of leak and vacuum suction can be adjusted. Further, the closed container (vacuum capsule) 8 is provided with a viewing window 20 and a spotlight 21 so that the inside of the closed container (vacuum capsule) 8 can be observed. Furthermore, a sealed container (vacuum capsule) 8
A heater 22 and a temperature sensor 23 are respectively installed on the top plate and the bottom plate 9 to control the temperature inside the closed container (vacuum capsule) 8.

The degree of vacuum in the sealed container (vacuum capsule) 8 is displayed on a vacuum gauge 24. When a predetermined degree of vacuum is reached, a timer is activated to maintain the degree of vacuum for a predetermined time. During that time, the material injected into the molding and shaping (mold) 3 is exposed to a vacuum, so that all internal air is exhausted.

Thereafter, the vacuum pump 10 is stopped, the vacuum valve 17 is closed, the outside air introduction (leak) valve 16 is opened, the vacuum is broken, and the inside of the sealed container (vacuum capsule) 8 returns to the atmospheric pressure. Then, the signal of the vacuum gauge 24 with a contact lowers the air cylinder 15 to lower the bottom plate 9 of the sealed container (vacuum capsule) 8. Next, the transfer device 7 returns and lifts the mold 3 and the gate 2 of the heat treatment device 12.
5 is opened and the mold 3 is opened.
In the inside, heat treatment is performed at a predetermined temperature for a predetermined time, and curing and vulcanization are performed to obtain a finished product.

[0015]

As described above, according to the method for casting rubber products of the present invention, there is no need to use a pressurized can or to confine the entire apparatus in a closed chamber and mix and inject (vacuum casting). In addition to solving the problem of large-sized equipment and safety problems, it is a method of transferring to a closed container after injection at normal pressure.
Of different sizes as long as they can be accommodated in a closed container
It can be easily adapted to various types of molding and
It is very practical with few parts replacement. In addition, it is possible to mold without air bubbles in a small facility, and furthermore, it is possible to achieve continuous and automatic operation in combination with the preceding and following devices and a transport system, thereby saving labor. Furthermore, in the case of batch work or manual work, it is easily affected by the outside air temperature, but in the case of the present invention, since conditions such as the passage time of each process are constant, a stable work with little variation in quality can be obtained. Can be In addition, the work environment can be improved by removing heavy 3K work, such as carrying heavy moldings and molds or carrying high-temperature materials by hand.

[Brief description of the drawings]

FIG. 1 is a side view showing a configuration of an entire line of an apparatus applied to a method of casting and molding a rubber product according to the present invention;

FIG. 2 is a side view showing details of a closed container (vacuum capsule) of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1 forming and shaping device 2 preheating device 3 forming and shaping device 4 centralized control panel 5 transport conveyor 6 mixing and injecting device 7 transfer device 8 sealed container (vacuum capsule) 9 bottom plate 10 vacuum pump 11 heat treatment device conveyor 12 heat treatment device 13 delivery conveyor DESCRIPTION OF SYMBOLS 14 Stopper 15 Cylinder 16 Outside air introduction leak valve 17 Vacuum valve 18, 19 Throttle valve 20 Viewing window 21 Spotlight 22 Heater 23 Temperature sensor 24 Vacuum gauge with contact 25 Gate

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masanobu Kanemoto 3-1-1, Sukekawa-cho, Hitachi City, Ibaraki Prefecture, “Inside the wire plant of Hitachi Cable Co., Ltd.” (56) References JP-A-1-122418 (JP) , A)

Claims (2)

(57) [Claims] 1. Immediately after a resin or a liquid rubber is injected into a mold or the like at a normal pressure by a mixing / injection device, the molding or the mold is immediately transferred to a sealed container (vacuum capsule), and the sealed container (vacuum capsule) is removed. by vacuum suction, gas or air contained in the resin or liquid rubber, molding or gutter (void) discharged, thereafter, return the sealed container to atmospheric pressure, this
Remove the mold and grout from the sealed container of
Cast molding method of a rubber product characterized in that a was put into a heat treatment apparatus so as to cure the resin or liquid rubber. 2. A casting apparatus in which a molding and grinding device, a preheating device, a mixing / injection device, a sealed container (vacuum capsule) and a heat treatment device are sequentially arranged, and a casting device in which these devices are connected by a conveyor. And liquid rubber are molded by the above-mentioned mixing and injecting device, and the molding and shaping are performed by mixing and injecting the rubber at normal pressure onto the bottom plate of a closed container (vacuum capsule), and the bottom plate is raised to form a closed container (vacuum capsule). To accommodate yato
At the same time, the hermetic container (vacuum capsule) is sealed, the degree of vacuum is maintained at a predetermined degree of vacuum for a predetermined time, and then the pressure is returned to normal pressure, and the mold is immediately put into a heat treatment apparatus to perform curing and vulcanization. Casting apparatus for rubber products, characterized in that: