JPH0642974B2 - Molding equipment for gas curing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a mold making apparatus, and in particular, after blowing molding sand into a mold, a hardening gas is injected to cure the molding sand in the mold. Thus, the present invention relates to an improvement in a gas curing molding apparatus that molds a mold.

(Prior Art) In general, a mold is filled with a molding sand kneaded with a binder by blowing, and then a hardening gas is injected into the molding sand to cure the molding sand to mold the molding sand mold. A so-called cold box method, which is a gas hardening type mold manufacturing method, is known. And, as an example of a molding machine for producing a mold using this method, there is the invention of Japanese Patent Publication No. 48-9246.

As shown in FIG. 5, the slide shutter 1 is installed in a slide case 2 fixed below the blow box 4.
Is slidably mounted, and a molding material blowing hole 5 is penetrated through the slide shutter 1, and
Reaction catalyst gas conduit 8 connected to one side of the shutter 1
Is formed with a reaction catalyst gas injection port 6 which is communicated with the gas passage 7 and is opened only to the pattern 9 side.

According to this, first, the molding material blowing hole 5 penetratingly formed in the slide shutter 1 is aligned with the blowing hole 3 formed in the upper portion of the slide case 2, and the molding material in the blow tank 4 is patterned. 9 and then the slide shutter 1 is slid as shown in the drawing so that the molding material filling port of the pattern 9 and the reaction catalyst gas jet hole 6 in the shutter 1 are aligned with each other, so that the reaction catalyst gas conduit 8 and the While injecting a reaction catalyst gas that is blown out through the gas passage 7 into the molding material in the pattern 9, the molding material is cured to mold a sand mold for casting. As a result, after the blowing of the molding material, the gassing step can be performed at the same position without moving the pattern 9 or the blow tank 4, and the time required for the molding step can be shortened.

(Problems to be Solved by the Invention) In the cold box method, amine gas or the like is generally used as a hardening gas, including the above-mentioned conventional examples. This amine gas has an excellent hardening function for molding materials such as foundry sand, but at the same time, it has harmful properties for the human body.
If the amine gas leaks to the outside during the gassing process, the working environment on the spot is deteriorated, which is not preferable in terms of environmental hygiene. Therefore, when using the curing gas such as the amine gas, consideration must be given to surely prevent the leakage of the curing gas to the outside.

However, in the above conventional example, the slide case 2
The sliding shutter 1 housed therein is slid as necessary to perform the blowing process and the gassing process. In this way, the sliding shutter 1 is slidable. Therefore, the slide shutter 1 and the slide case 2
It is very difficult to add a sealing function of preventing the reaction catalyst gas (curing gas) from leaking to the outside during the gassing step. In addition, the sliding of the slide shutter 1 with respect to the slide case 2 makes it difficult to avoid wear of both of them. If it gets caught between the two, the wear of both is further promoted.

In this case, the reaction catalyst gas (curing gas) supplied into the slide shutter 1 during the gassing process leaks to the outside from between the shutter 1 and the slide case 2, and as described above. It goes without saying that the working environment on the spot is deteriorated, and when the gas flows into the blow tank 4 through the blowing hole 3 formed in the upper part of the slide case 2, the inside of the tank is The unused foundry sand was hardened and hindered the subsequent blowing process.

Therefore, the present invention, in a gas hardening molding apparatus for molding a sand mold for casting using the cold box method, it is possible to perform a blowing step and a gassing step at the same position as in the above-mentioned conventional example, and further, at the time of the gassing step. An object of the present invention is to surely prevent the hardening gas from leaking so as not to adversely affect the working environment and the unused molding sand stored in the molding apparatus.

(Means for Solving the Problem) That is, according to the present invention, after the foundry sand stored in the sand tank is filled into the mold through the blow hole formed in the lower surface of the tank, In a gas curing molding apparatus configured to mold a mold by injecting a curing gas into the molding sand therein to cure the molding sand, the molding apparatus is provided above the sand tank and is separated from the tank by a partition wall. Gas supply chamber, a nozzle tip made of an elastic material that is attached to the lower end of the blow hole and is pressed against a molding sand filling port provided in the mold, and a sand tank so that one end faces the blow hole. A tubular nozzle positioned inside and having the other end penetrating the partition wall and projecting into the supply chamber; and a predetermined gap between the tip of the nozzle and the blow hole by constantly urging the nozzle upward. Elastic member to be formed, and While providing a pressing plate for fitting the tip of the nozzle into the nozzle chip by pressing the tubular nozzle against the elastic member, when fitting the nozzle into the nozzle chip,
It is characterized in that the outer peripheral surface of the nozzle tip is crimped by the inner peripheral surface of the nozzle tip.

(Operation) According to the above configuration, the nozzle tip made of the elastic material, which is mounted on the lower end of the blow hole in the sand tank, is pushed into the molding sand filling port provided in the mold, whereby the filling port and the blow port are blown. If pressurized air is introduced into the sand tank while communicating with the holes, the molding sand in the sand tank will be blown into the mold. After that, by pressing the tubular nozzle against the elastic member by the pressing plate to lower it and inserting the tip of the nozzle into the nozzle tip, and then introducing the pressurized curing gas into the gas supply chamber, The hardening gas is injected into the mold through the tubular nozzle whose one end penetrates into the gas supply chamber, so that the casting filled in the mold is hardened. At this time,
Since the nozzle tip is strongly pressed against the molding sand filling port provided in the mold, the curing gas injected into the mold does not leak outside between the filling port and the nozzle chip. . Further, the tip of the tubular nozzle is forcibly inserted under the condition that the inner diameter of the nozzle tip is contracted under the influence of its reaction force by strongly pressing the nozzle tip against the filling port. By virtue of this, the inner peripheral surface of the nozzle tip strongly seals the outer peripheral surface of the distal end of the tubular nozzle, so that the curing gas is sandwiched between the nozzle tip and the nozzle via the blow hole. It does not flow back into the tank. As a result, the working environment is not deteriorated and the unused molding sand in the sand tank is not hardened.

(Example) Next, the specific Example of this invention is described based on drawing.

As shown in FIG. 1, the gas curing molding apparatus 11 according to this embodiment is supported by the frame 12 in a suspended manner, and the lower surface 13a is in contact with the upper surface of the mold A installed below. A sand tank 13 serving as a blow head part and a gas supply chamber 1 integrally provided above the sand tank 13 via a partition wall 14.
5 and. The sand tank 13 and the gas supply chamber 15 are attached to the lower end portion of 17 which is projected downward from the lifting cylinder 16 installed on the upper surface of the frame 12, and the hydraulic pressure (or pneumatic pressure) to the cylinder 16 is provided.
By the vertical movement of the piston 18 due to the supply and discharge of the above, the piston 18 is moved up and down through the piston rod 17 between a position shown in the figure and a position above a certain stroke thereof. A plurality of guide rods 19 ... 19 are erected on the upper surface 15a of the gas supply chamber 15, and these rods 19 ... 19 are respectively fixed to guide sleeves 20 ... 20 fixed to the upper surface of the frame 12. The sand tank 13 and the supply chamber 15 are vertically movable while being guided by them.

The piston rod 17 has a hollow pipe shape, the lower end of which is penetrated from the upper surface 15a of the gas supply chamber 15 through the supply chamber 15 and the partition wall 14 into the sand tank 13, and the rod 17 is also provided. Inside the pipe 2
1 is inserted. And the rod 17 and the pipe 2
1 is an air passage 22 communicating with the inside of the sand tank 13, and the end of the rod 17 protruding from the upper end of the cylinder 16 is connected to the air passage 22 from a pressurized air source (not shown). Or sand tank 13
An air inlet 23 to the inside is provided. A sand passage 24 is also provided inside the pipe 21 and communicates with the inside of the sand tank 13. At the upper end of the pipe 21, a sand feeder (not shown) is provided to the sand passage 24 or inside the sand tank 13. The sand supply port 25 for introducing the casting sand B previously kneaded with the binder is provided, and the pipe 2 is provided at the opening 24a to the sand tank 13 at the lower end of the sand passage 24.
The cylinder 21 installed at the upper end of the pipe 21
An on-off valve 2 that is moved up and down via a rod 27 that penetrates the inside.
8 is provided so that the molding sand B is supplied into the sand tank 13 through the sand passage 24 when the opening / closing valve 28 opens the opening 24a.

However, in the sand tank 13, a plurality of cylinders 29 ... 29 which are erected from the bottom thereof are arranged. 29a are formed in the lower side surface of the lower surface 13a of the sand tank 13 and have holes 29a ... 29a which open to a plurality of blow holes 30. The inside is a hollow tubular nozzle 31 ...
Each of the tubular nozzles 31 is urged upward by a spring 32 mounted in the tubular body 29 and normally held at the upper end position shown in the drawing. The upper end 31a of each tubular nozzle 31 is projected into the gas supply chamber 15, and the upper end 31a
A plurality of inlets 31b for allowing the hardening gas to flow into each tubular nozzle 31 at the time of the gassing process are provided in the circumferential direction as shown in the drawing, and the lower end 31b is provided.
c projects into the blow hole 30 so as to form a predetermined gap with the blow hole 30. In addition, the hole 29a communicating with the blow hole 30 in each tubular body 29 is provided in an inclined shape at a predetermined angle in order to smoothly blow out the molding sand B. Is set so that the casting sand B does not fall from the blow hole 30 when the is not introduced.

Here, the blow holes 30 ... 30 correspond to the positions of the filling ports A ″ ... A ″ of the molding sand B which are provided on the upper wall of the mold A (upper mold A ₁ ) and communicate with the cavity A ′. Nozzle chips 33 ... 33 made of elastic material are attached to the lower ends of the blow holes 30.
Lower surface of the sand tank 13 (blow head) as shown
When the nozzle tip 33 is pressed against the filling port A ″, the blow holes 30 ... 30 and the filling ports A ″ ... A ″ communicate with each other when the nozzle tip 33 is pressed against the filling port A ″. In this case, as shown in an enlarged view in Fig. 2, the nozzle tip 33 seals the communicating portion between the blow hole 30 and the filling port A ", and the nozzle tip 33 is filled. It is pressed by the mouth A ″ and its inner diameter is reduced.

On the other hand, in the gas supply chamber 15, a pressing plate in which a boss portion 34a is vertically slidably fitted to the outer peripheral surface of the piston rod 17 penetrating the supply chamber 15 and protruding into the sand tank 13. 34 is positioned immediately above the upper end 31a of the tubular nozzle 31, and a pressing plate 34 is provided on the upper surface 15a of the supply chamber 15 via piston rods 35 ... Cylinders 36 ... 36 that are moved vertically with respect to the position (see FIG. 3) are fixed. Further, an inlet pipe 37 for introducing a hardening gas or pressurized air from respective supply sources (not shown) to the side wall 15b of the gas supply chamber 15 depending on the gassing process and the blowing process. Is connected to the inlet 38.

At the bottom of the lower mold A ₂ that constitutes the mold A, a discharge for discharging the curing gas injected into the cavity A ′ into the suction passage 39 formed in the pedestal C during the gassing process. The passage 40 is provided and the passage 40
A vent plug 41 having a net for preventing leakage of foundry sand is attached to the upper end of the vent plug 41.

Next, the operation of this embodiment will be described. First, as shown in FIG. 1, a required amount of foundry sand B is supplied into the sand tank 13 from the sand passage 24, and the tank 13 is lowered by the lifting cylinder 16, and its lower surface 13a is set downward. The upper surface of the existing mold A (upper mold A ₁ ) is brought into contact with it. At this time, the blow hole 30 formed in the lower surface of the sand tank 13
The nozzle tip 33 made of elastic material attached to the lower end of
Pressed by the filling port A ″ opened on the upper wall of the upper mold A ₁ ,
As a result, the cavity A ′ formed in the sand tank 13 and between the upper molds A ₁ and A ₂ forming the mold A is defined by the introduction port 29a, the blow hole 30, the nozzle tip 33 and the upper mold of the cylindrical body 29. It is communicated via the filling port A ″ at A ₁ .

Next, in this state, pressurized air is introduced into the sand tank from the inlet 23 provided at the upper end of the piston rod 17 through the air passage 22, and is also introduced into the gas supply chamber 15 at least into the sand tank. If pressurized air having a pressure equal to or higher than that of the pressurized air introduced is introduced through the introduction port 38, the molding sand B stored in the tank 13 will have the above-mentioned holes due to the pressure of the air. 29A, the blow hole 30, the nozzle tip 33, and the filling port A ″ to fill the cavity A ′ of the mold A. At this time, the pressurized air introduced into the gas supply chamber 15 is the tubular nozzle 31. The tip 3 of the nozzle 31 passing through the inside
Since it flows out from the 1c into the blow hole 30, the inflow of the molding sand B from the inside of the sand tank 13 into the cavity A'of the mold A is promoted, and the filling of the casting B into the cavity A'is more effective. This tubular nozzle 31
The pressurized air flowing out from the tip portion 31c of the nozzle prevents the casting sand B from flowing back into the nozzle 31, and the nozzle tip portion 31c
Is not blocked by the foundry sand B.

Then, while the molding sand B is filled in the cavity A ′ of the mold A, the cylinders 36 ... 36 installed on the upper surface 15a of the gas supply chamber 15 are operated to lower the pressing plate 34, and When the upper end portion 31a of the nozzle 31 is pressed and the nozzle 31 is lowered against the spring 32, the tip end portion 31 of the nozzle 31 as shown by the chain line in FIG.
When c is pressed against the filling port A ″ of the upper mold A _1, the c is forcibly fitted into the nozzle tip 33 whose inner diameter is narrowed, and the introduction port 3 formed at the upper end 31 a of the nozzle 3
1b is projected into the gas supply chamber 15. In this state, if the curing gas pressurized is supplied into the gas supply chamber 15 through the introduction port 38, the curing gas flows into the introduction port 31b protruding into the gas supply chamber 15,
The hardening gas is injected through the tubular nozzle 31 into the molding sand B filled in the cavity A ′ of the mold A to cure the molding sand B, whereby the core of the cavity A ′ is formed. It will be molded. At this time, since the nozzle tip 33 is made of an elastic material and is strongly pressed against the filling port A ″ of the upper die A ₁ of the mold A, the nozzle tip 33 is brought into close contact with the filling port A ″. The hardening gas injected into the cavity A'does not leak to the outside from between the filling port A "and the nozzle tip 33. Further, the outer peripheral surface of the distal end portion 31c of the tubular nozzle has the inner diameter reduced as described above. Since the peripheral surface is sealed by the inner circumference of the nozzle tip 33 thus formed, the above-mentioned curing gas is applied to the nozzle tip 3
3 does not flow back into the sand tank 13 between the nozzle 3 and the tubular nozzle 31. As a result, the working environment is not deteriorated due to the leakage of the hardening gas to the outside, and the backflow of the hardening gas into the sand tank 13 is prevented to cure the unused sand in the tank. Never.

When the core is formed in the mold A in this way, the pressurized air is supplied again into the gas supply chamber 15 through the inlet 38, so that the mold A as well as the inside of the supply chamber 15 is supplied.
The curing gas filled in the cavity A'of
After introducing the curing gas into the neutralization tank (not shown) provided at a predetermined position through the discharge passage 40 provided in the lower mold A ₂ and the suction passage 39 formed in the pedestal C, The elevating cylinder 16 operates and the sand tank 13 is elevated to the upper position via the piston rod 17 as shown in FIG. Further, after the sand tank 13 is raised, the upper die A _{1 of the} die A is elevated by the separately provided lifting means D, D, and the die A is opened.
At this time, the core is formed in the cavity A 'E is increased with the upper mold A ₁ remain attached to the lower the upper mold A _1.

Then, as shown in FIG. 3, with the upper surface of the upper mold A _{1 in contact} with the lower surface 13a of the sand tank 13 again, the cylinder 36 fixedly mounted on the upper surface of the gas supply chamber 15 is operated to press the pressing plate. 34 to lower the tip portion 3 of each tubular nozzle.
If 1c is projected further downward than during the gassing process,
Tip portion 31c is to be plunged into the filling opening A "in the upper mold A _1. Forcibly Thus, the core has been attached to the lower upper mold A ₁ E is from the upper mold A ₁ Is separated into
It will be taken out on the receiving member F carried in below.
That is, the tubular nozzles 31 ... 31 can also be applied as eject pins for taking out the core E.

Incidentally, as shown in an enlarged manner in FIG. 4, the tubular nozzle 31 '
A plurality of slits 42a '...
You may comprise so that the nozzle cap 42 'in which 42a' was formed may be mounted. By doing so, it is possible to more effectively prevent the backflow of the molding sand B into the tubular nozzle 31 'in the blowing step.

(Effect of the Invention) As described above, according to the present invention, the hardening gas is injected from the inside of the sand tank into the molding sand filled in the mold through the blow hole provided on the lower surface of the tank to cure the molding sand. In the molding device for gas curing, which is configured to cure and mold the mold,
A gas supply chamber partitioned by a partition wall is integrally provided on the upper part of the sand tank, and a tubular nozzle having one end protruding into the gas supply chamber and the other end facing the blow hole is provided. The tip of the tubular nozzle is inserted into the nozzle tip attached to the lower end of the blow hole to inject the curing gas supplied into the gas supply chamber into the mold, so that the blowing is performed at the same position. The process and the gassing process can be performed, and the time required for the casting molding process can be shortened. Furthermore, during the gassing process,
Since the tip outer peripheral surface of the tubular nozzle is pressed by the inner peripheral surface of the nozzle tip whose inner diameter is narrowed by being pressed by the filling port of the mold, it is ejected from the tip of the tubular nozzle. The sealing property with respect to the curing gas is remarkably improved, and it is possible to reliably prevent not only the leakage of the curing gas to the outside but also the backflow into the sand tank. As a result, the working environment is not deteriorated and the unused foundry sand in the sand tank is not hardened.

[Brief description of drawings]

FIG. 1 is an overall vertical sectional view showing a state of a gas curing molding apparatus according to the present embodiment during a blowing process, FIG. 2 is an enlarged sectional view of an essential part of the gas curing molding apparatus, and FIG. 3 is an eject. FIG. 4 is a longitudinal sectional view of a main part showing a state during a process, FIG. 4 is an enlarged sectional view showing another embodiment of the tip portion of the tubular nozzle, and FIG. 5 is a vertical sectional view showing a conventional mold making machine. 13 ... Sand tank, 14 ... Partition, 15 ... Gas supply chamber, 30, 30 ... Blow hole, 31, 31 ... Tubular nozzle, 32, 32 ... Spring (elastic member), 33,
33 ... Nozzle tip, 34 ... Pressing plate, A ...
Mold (A ₁ ... upper mold, A ₂ ... lower mold), A "... filling port, B ... casting sand.

Claims (1)

[Claims] 1. A mold sand is filled with molding sand stored in a sand tank through a blow hole formed in the lower surface of the tank, and then a hardening gas is injected into the molding sand in the mold. A molding apparatus for gas hardening, which is configured to mold a mold by hardening the foundry sand, wherein a gas supply chamber provided at an upper portion of the sand tank and partitioned from the tank by a partition, and the blow A nozzle tip made of an elastic material that is attached to the lower end of the hole and is pressed against the foundry sand filling port provided in the mold, and the other end is located in the sand tank so that one end faces the blow hole and the other end A tubular nozzle penetrating the partition wall and projecting into the gas supply chamber; an elastic member for constantly urging the nozzle upward to form a predetermined gap between the tip of the nozzle and the blow hole; Against the elastic member A pressing plate for fitting the tip of the nozzle into the nozzle tip by pressing, so that the outer peripheral surface of the nozzle tip is crimped by the inner peripheral surface of the nozzle tip when the nozzle is fitted into the nozzle tip. A molding apparatus for gas curing, which is configured.