JPH0626819B2 - Casting machine mouth device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application] The present invention relates to a mouth device attached to a resin injection port or an overflow port of a casting mold.

(Prior Art) For example, in a cast molding machine for molding a large-sized molded product such as a bathtub, a raw material resin such as an acrylic resin is injected into a cavity from a resin injection port provided at the bottom of the molding die. Along with this, the air in the cavity is discharged from the overflow port provided in the upper part of the molding die.

Conventionally, as a method of filling the raw material resin, a resin supply hose with a valve is connected to the resin injection port of the molding die, the raw material resin is pumped by a pump and the valve is opened to inject the raw material resin into the molding die, In general, the procedure is to close the valve after confirming that the raw material resin has filled the cavity of the molding die and overflowed from the overflow port. However, with this method, the mold and its surroundings are contaminated by the raw material resin that overflows from the overflow port, which requires time to clean, and the worker pays close attention to the moment when the raw material resin overflows from the overflow port each time the raw material resin is injected. Must-have. For this reason, in this type of cast molding machine, there has been a strong demand for preventing the raw material resin from overflowing and automating the injection work.

As a technique to meet such a demand, it has been considered to attach a mouth device having a function of automatically blocking a raw material resin to a resin injection port or an overflow port of a molding die. As shown schematically in FIG. 14, this is a mouth main body 2 having a communication passage 1 continuous in the cavity of a molding die (not shown).
The valve body 3 is movably provided so that the communication passage 1 can be opened and closed, and the resin supply hose 4 is connected to the connection port provided in the mouth main body 2, and the raw material resin is pumped from the resin supply hose 4. And is made to flow into the cavity through the communication passage 1. With this configuration, when the raw material resin is filled in the cavity of the molding die, the filled raw material resin pushes up the valve body 3 and closes the communication passage 1, so that the supply of the raw material resin is automatically cut off. It is.

A similar port device is attached to the overflow port side, and the valve body 3 is initially opened, and the air expelled from the cavity when the raw material resin is injected is discharged through the communication passage 1. Then, when the raw material resin fills the inside, the valve body 3 is also pushed up by the raw material resin and the communication passage 1
Will be closed, and thus the raw material resin will be prevented from overflowing.

(Problems to be Solved by the Invention) However, in the above configuration, since the closing operation of the communication passage 1 is performed depending on the movement of the raw material resin itself, the reliable closing operation may not be performed. Therefore, there is a problem that the automatic shutoff function of the raw material resin is inferior in reliability, and sometimes the raw material resin overflows from the overflow port without being noticed.

Therefore, an object of the present invention is to provide a mouth molding device of a casting machine capable of reliably blocking the raw material resin, preventing the raw material resin from overflowing, and automating the resin injection work.

[Structure of the Invention] (Means for Solving the Problem) A mouth device of a casting machine according to the present invention is a mouth device which is attached to a resin injection port or an overflow port of a molding die into which a raw material resin is injected. A mouth main body having a communication passage communicating with the cavity of the molding die, a valve portion provided in the mouth main body for opening and closing the communication passage, and a filling detection sensor for detecting that the raw material resin is filled in the molding die. And a valve drive mechanism that closes and operates the valve section on condition that the filling resin has detected the filling of the raw material resin.

(Operation) Raw material resin is injected into the molding die through the communication port of the mouth body. When the raw material resin is filled in the cavity, it is detected by the filling detection sensor, the valve drive mechanism operates the valve portion to close the communication passage, and the flow of the raw material resin is shut off. In this way, the valve drive mechanism forcibly closes the valve portion, so that the reliability of the shutoff function is significantly increased.

(Embodiment) A first embodiment in which the present invention is applied to a bathtub casting machine will be described with reference to FIGS. 1 to 8.

The overall structure of the casting machine is as shown in FIG. A pair of gate-shaped columns 12 are erected on the base 11, and each column 1
Bearings 13 are fixed to the upper portions of the two. Both stanchions 1
A support frame 14 is arranged between the two, a support shaft 15 protruding from the support frame 14 is received by the bearing 13, and a hydraulic cylinder 16 is provided between the support frame 14 and the column 12. A molding die 17 for molding the bathtub by casting is attached to the support frame 14 and can be rotated integrally with the support frame 14 by operating the hydraulic cylinder 16.

The molding die 17 is composed of a lower die 18 and an upper die 19, and a cavity 20 (schematically indicated by a broken line in the figure) formed of an electroforming surface for bathtub molding is formed inside in a state where the two dies are matched with each other. . A raw material resin such as an acrylic resin is injected into the cavity 20 as described later, and a heating device for heating the raw material resin to, for example, about 100 ° C. to cure the raw material resin. Is built in the molding die 17. The resin injection port 2 is provided in a portion of the molding die 17 located at the lower end in the state shown in FIG.
1 is provided, and an overflow port 22 is provided at a portion located at the upper end. Since the structures of both are the same, the structure of the resin injection port 21 will be described below.
As shown in the figure, two mating plates 23 that are in contact with each other are extended from the mating portions of the lower mold 18 and the upper mold 19. Further, as shown in FIG. 1, a fan-shaped runner recess 24 is formed in the mating plate 23 on the upper mold 19 side, and a through hole 25 connected to the runner recess 24 is formed in a penetrating state. A sealing gasket 26 is arranged around the runner recess 24. When the upper and lower molds 18 and 19 are matched with each other, the runner recess 24 has the matching plate 2 on the lower mold 18 side.
The lid is closed by 3, and the inside of the cavity 20 is in communication with only the through hole 25 through the runner recess 24.

Now, a mouth device embodying the present invention is attached to each of the resin injection port 21 and the overflow port 22 configured as described above, which will be described in detail below. First, as shown in FIGS. 1 to 3, the mouth device attached to the resin injection port portion 21 is provided with a cylindrical mouth body 27, and the inner space thereof is connected to the cavity 20 of the molding die 17. The passage 28 is formed, and a flange portion 27a is integrally formed near one end. Then, one end of the mouth body 27 is fitted into the through hole 25 formed in the matching plate 23 on the upper mold 19 side, and the flange 27a is bolted with the sealing packing 29 sandwiched between the flange 27a and the matching plate 23. It is fixed at 30. Furthermore, mouth body 2
A connection port body 31 and a drain port 32 are provided on the peripheral wall portion of 7, and a resin supply hose 33 connected to a raw material resin supply pump (not shown) is connected to the connection port body 31 and a drain port 32.
A drain valve 34 is connected to the.

On the other hand, a bush 35 is attached to the other end of the mouth main body 27, and a valve shaft 37 made of, for example, a fluororesin having an O-ring 36 attached thereto is slidably provided.
An inversely tapered valve portion 37a is formed at the lower end portion of the valve shaft 37, and the valve portion 37a can be fitted into the lower end opening of the communication passage 28 of the mouth body 27 formed in a similar tapered shape. Therefore, this valve portion 37a is
As shown in the figure, the communication passage 28 of the mouth main body 27 is opened in the state of being lowered, and as shown in FIG. 3, it is raised and the lower end of the valve shaft 37 is fitted into the lower end opening of the communication passage. In this state, the communication passage 28 is closed.

A cylinder bracket 38 is provided on the upper end of the mouth body 27, and a hydraulic cylinder 39 corresponding to a valve drive mechanism is fixed on the cylinder bracket 38. A metal ring 40 is screwed to the upper end portion of the valve shaft 37 protruding into the cylinder bracket 38, and the proximity switch 41 is located in the moving region of the metal ring 40 as the valve shaft 37 moves up and down. Are fixed to the cylinder bracket 38. The proximity switch 41 detects that the metal ring 40 approaches when the cavity 20 of the mold 17 is filled with the raw material resin and the valve shaft 37 made of the fluororesin is lifted up. It functions as a filling detection sensor that detects that the raw material resin is filled in the mold 17. A vertically long connecting hole 43 is formed in the cylinder knuckle 42 connected to the rod 39a of the hydraulic cylinder 39, and a connecting pin 44 is fixed to the upper end of the valve shaft 37, and the connecting pin 44 is connected. The valve shaft 37 and the rod 39a of the hydraulic cylinder 39 are engaged with each other by being fitted into the hole 43. The signal line from the proximity switch 41 is input to a control circuit (not shown), and when the molding resin 17 is filled with the raw material resin and the proximity switch 41 is operated, the hydraulic cylinder 39 is operated by the signal from the control circuit, and thus the valve is operated. The shaft 37 is pulled up to close the valve portion 37a.

Next, the mouth device attached to the overflow mouth portion 22 is
As shown in FIGS. 1 to 6, the configuration is similar to the mouth device on the resin injection port 21 side shown in FIGS. 1 to 3.
Therefore, the same parts are designated by the same reference numerals, detailed description thereof will be omitted, and different parts will be mainly described. First, the mouth main body 2
Two openings are formed in 7, and a valve 45 is attached to each of them. A flange 46 is formed on the upper end of the valve shaft 37, and a compression spring 47 is provided between the flange 46 and the upper end of the cylinder bracket 38.
As a result, the valve shaft 37 is always urged downward, and the valve 37a keeps the communication passage 28 open. This is because when the raw material resin is injected, the air in the cavity 20 of the molding die 17 is pushed out through the communication passage 28 of the mouth body 27 and the valve 45, so that the valve shaft 37 is lifted and the valve portion 37a is naturally formed. This is to prevent it from closing. Others, valve shaft 3
7, the metal ring 40 is attached to the valve shaft 3
The hydraulic cylinder 39 when 7 is raised to the position shown in FIG.
Is operated to forcibly close the valve portion 37a as shown in FIG.
It is exactly the same as the side mouth device.

Next, the operation of this embodiment will be described. Prior to the injection of the raw material resin, as shown in FIGS. 1 and 4, each valve portion 37a of each port device is open. Further, the drain valve 34 provided in the port device on the resin injection port 21 side is closed, and the valve 45 provided in the port device on the overflow port 22 side is opened.

Now, the raw material resin is fed into the cavity 20 of the molding die 17 from the mouth device on the resin injection port 21 side. The flow path of the raw material resin flows from the resin supply pump to the resin supply hose 33, the connection port body 31, the communication passage 28 of the port body 27 and the runner recess 2 of the mating plate 23 as shown by the arrow in FIG.
4 to reach the inside of the cavity 20. In addition, with the supply of the raw material resin, the air in the cavity 20 is discharged to the outside through the communication passage 28 and the valve 45 of the mouth device on the overflow mouth 22 side. When the supply of the raw material resin progresses and the inside of the cavity 20 is filled with the resin, the valve shaft 37 of the mouth device on the overflow mouth 22 side is lifted by the raw material resin that has entered the runner recess 24,
As shown in FIG. 5, the metal ring 40 is a proximity switch 41.
And the hydraulic cylinder 39 operates based on the signal from the proximity switch 41. As a result, the valve shaft 37 is sufficiently pulled up, and as shown in FIG.
7a is completely closed.

As a result, since the inflow of the raw material resin is blocked, the valve shaft 37 also slightly rises in the mouth device on the resin injection port 21 side, and the metal ring 40 approaches as shown in FIG. The switch 41 comes closest to the switch 41, and a signal from the proximity switch 41 activates the hydraulic cylinder 39 of the mouth device on the resin injection port 21 side.
As shown in FIG. 3, the valve shaft 37 is sufficiently pulled up to forcibly close the valve portion 37a. Such a state where the raw material resin is forcibly shut off is maintained until the raw material resin filled in the cavity 20 is cured, and a situation in which the excess raw material resin is continuously supplied and the raw material resin overflows is reliably prevented.

As described above, according to this embodiment, the work of injecting the raw material resin can be completely automated, and the efficiency of the casting work can be greatly improved. Moreover, when the molding die 17 is filled with the raw material resin, the valve portions 37a are forcibly closed, so that the supply of the raw material resin is reliably cut off, and the excessive raw material resin is supplied to the raw material resin. It is possible to prevent resin overflow from occurring.

While the filling resin in the cavity 20 is cured, if the heat dissipation of the mouth device on the side of the resin injection port 21 is sufficiently ensured, the raw material resin remaining in the mouth main body 27 is removed from the molding die 17. It does not cure under the heat of. However, if the heat dissipation is insufficient, it may be forcibly cooled or the drain valve 34 may be opened after the valve portion 37a is closed to discharge the residual resin. In addition, in the unlikely event that the raw material resin enters the communication passage 28 of the port device on the side of the overflow port 22, the valves 4 provided there are provided.
After opening 5, the cleaning liquid can be flowed into the communication passage 28 to clean the inside.

Furthermore, the present invention is not limited to the above-mentioned first embodiment, and can be implemented by variously modifying as follows, for example.

(1) Second Embodiment The proximity switch 41 is not provided in the mouth device on the side of the resin injection port 21, and the hydraulic cylinder of the mouth device on the side of the resin injection port 21 is provided based on the signal from the proximity switch 41 of the overflow port 22. 39 can be activated. Even in this case, since the filling of the raw material resin can be detected and each valve portion 37a can be completely closed, the supply of the raw material resin can be automatically and reliably shut off.

(2) Third Embodiment The filling detection sensor is not limited to the structure shown in the first embodiment. For example, the fact that the internal resin pressure rises when the filling of the raw material resin is completed is used to detect it. You may For that purpose, for example, as shown in FIG. 9, a pressure sensor 50 for detecting the resin pressure in the runner recess 24 is provided in the mating plate 23 portion of the resin injection port 21, and the pressure changes so as to exceed a certain value. At that time, it may be considered that the filling of the raw material resin is completed.

(3) Fourth Embodiment With respect to the filling detection sensor, for example, when the liquid level of the raw material resin in the molding die rises, the characteristic of the molding die temperature at that portion lower than the preheating temperature can be utilized. To this end, for example, as shown in FIG. 10, a temperature sensor 60 such as a thermocouple is provided in the vicinity of the overflow port 22 of the molding die 17, and the temperature detected by the temperature sensor 60 is lowered to a certain value or less. At this time, it may be considered that the filling of the raw material resin is completed.

When the filling detection sensors having the configurations of the third and fourth embodiments are provided, the proximity switch 4 of the first embodiment is provided.
1 is not necessary, of course, and the hydraulic cylinder 3 of the port device on the resin injection port 21 side or the overflow port 22 side based on the signal from the pressure sensor 50 or the temperature sensor 60.
9 may be activated.

(4) Fifth Embodiment Even if the structure of the present invention is not necessarily adopted in the mouth device on the overflow port side, as shown in FIG. 11, for example, the inside of the runner recess 24 on the overflow port 22 side is exposed to the outside. It is possible to adopt a structure in which a perforated plug 71 having air permeability is fitted into the continuous through holes 25. With this configuration, when the raw material resin is injected, the air in the cavity freely passes through the porous stopper 71, and the raw material resin is filled in the molding die and flows into the porous stopper 71. As shown in, the porous plug 71 is blocked by the raw material resin having high viscosity, and the resin pressure inside rises sharply. Therefore, when the proximity switch 41 as in the first embodiment is provided in the mouth device on the resin injection port 21 side, the filling of the resin can be detected by the valve shaft 37 moving in the closing direction. When the pressure sensor 60 as in the embodiment is provided,
By the operation of the pressure sensor 60, the filling of the raw material resin can be detected. In this configuration, since the raw material resin that has entered the porous plug 71 is hardened together with the molded product, the porous plug 71 is housed in the sleeve 72 or the like so that it can be replaced at each molding. It is necessary to keep it. As a material of the porous plug 71, glass mat, urethane foam, porous sintered ceramic, plastic or the like can be used.

(5) Sixth Embodiment In the fifth embodiment, as shown in FIG. 13, the through hole 25 may be forcibly closed by the closing member 81 operated by the hydraulic cylinder 80.

(6) Others For example, the valve drive mechanism is not limited to the hydraulic cylinder, but may be an air cylinder, an electromagnetic solenoid, or the like.
Further, the valve of the port device on the overflow port side may be provided if necessary, and the present invention can be variously modified and implemented without departing from the scope of the invention.

[Effects of the Invention] As described above, according to the mouth device of the casting machine according to the present invention, the raw material resin can be surely blocked, and the raw material resin can be prevented from overflowing and the resin injection work can be automated. It has an excellent effect of being able to.

[Brief description of drawings]

1 to 8 show a first embodiment of the present invention. Of these, FIGS. 1 to 3 are vertical cross-sectional views of the mouth device on the resin injection port side, showing different states. 4 to 6 are vertical cross-sectional views of the mouth device on the overflow mouth side, each showing a different state. FIG. 7 is a perspective view showing the entire casting machine, and FIG. 8 is an enlarged perspective view of a resin injection port portion. FIG. 9 is a partial perspective view showing the third embodiment of the present invention, and FIG.
FIG. 11 is a partial vertical sectional view showing a fourth embodiment of the present invention, FIGS. 11 and 12 are vertical sectional views showing a fifth embodiment of the present invention in different states, and FIG. 13 is a sixth embodiment of the present invention. It is a longitudinal cross-sectional view showing an example. FIG. 14 is a schematic vertical sectional view showing a conventional mouth device. In the drawings, 17 is a molding die, 20 is a cavity, 21 is a resin injection port, 22 is an overflow port, 27 is a port body,
28 is a communication passage, 32 is a drain port, 33 is a resin supply hose, 37 is a valve shaft, 37a is a valve portion, 39 is a hydraulic cylinder (valve drive mechanism), 40 is a metal ring,
41 is a proximity switch (filling detection sensor), 50 is a pressure sensor (filling detection sensor), and 60 is a temperature sensor (filling detection sensor).

Claims (1)

[Claims] 1. A mouth device attached to a resin injection port or an overflow port of a molding die into which a raw material resin is injected, the mouth body having a communication passage communicating with the cavity of the molding die, and the mouth body. A valve portion provided in the main body for opening and closing the communication passage, a filling detection sensor for detecting that the molding resin is filled with the raw material resin, and the filling detection sensor for detecting the filling of the raw material resin into the molding die. A mouth device of a casting machine comprising a valve drive mechanism for closing and operating the valve portion under the above conditions.